We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angl...We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners＇ cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.展开更多
The maximal entropy ordered weighted averaging （ME-OWA） operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the...The maximal entropy ordered weighted averaging （ME-OWA） operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the methods for aggregating metasearch engine results are divided into two kinds. One has a unique solution, and the other has multiple solutions. The proposed method not only has crisp weights, but also provides multiple aggregation results for decision makers to choose from. In order to prove the application of the ME-OWA operator method, under the context of aggregating metasearch engine results, an example is given, which shows the results obtained by the ME-OWA operator method and the minimax linear programming （ minimax-LP ） method. Comparison between these two methods are also made. The results show that the ME-OWA operator has nearly the same aggregation results as those of the minimax-LP method.展开更多
Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative ...Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation gene （opd） into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, Pp,bA. From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25~C, the whole-cell activities of the transgenic Anabaena and Nostoc strains were 0.163~0.001 and 0.289~0.042 unit/gg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites.展开更多
The coaggregating behavior of the cationic kinetic probe P16;with different types of surfactants are in complete agreement with predictions based on the newly proposed ESAg concept.
Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the me...Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the methods which have been used to enhance sustainable exploitation of fisheries resources is the use of Fish Aggregating Devices (FADs). The study was conducted in two areas along the Kenyan coast which are: Msambweni in the southern part and Kuruwitu (Vipingo) in the northern part of the Kenyan coast. A combination of systematic site surveys: structured and semi structured interviews with key informants (community leaders and resource users);participant observations;descriptions of daily and seasonal time use;and analyses of secondary sources, such as fisheries records, was used to gather information and triangulate results. The perception of the community about FADs was determined by conducting a socio-economic survey before and after deploying FADs. Colonization and biomass survey around the deployed FADs was undertaken and fish associated with FADs was recorded. Results indicate that nine families of fish aggregated around FADs and at different distances. Catch and effort at FADs have been evaluated by monitoring catch data from fishers on daily basis after deployments.展开更多
The influence on fine particle aggregation and flotation behavior induced by high intensity conditioning(HIC) from saturated of the slurry with CO2 saturation was investigated.Bubble size measurements were conducted.T...The influence on fine particle aggregation and flotation behavior induced by high intensity conditioning(HIC) from saturated of the slurry with CO2 saturation was investigated.Bubble size measurements were conducted.The effect of dissolved gas,xanthate addition and agitation speed on fine sphalerite particle aggregation-and flotation-behavior were studied.The results show that during HIC in air or CO2 saturated water xanthate acts as a frother.The dissolved gas content in the pulp and HIC play a synergistic role in promoting fine particle aggregation and hence flotation;a significantly enhanced aggregation of fine sphalerite particles in a CO2 saturated slurry by HIC is observed.The aggregate size increased when the agitation speed was increased from 700 r/min to 1500 r/min.Increasing the HIC speed to 1500 r/min caused a positive impact on flotation kinetics.Further increasing the speed to 2000 r/min resulted in an adverse effect on flotation kinetics.展开更多
The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amp...The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amphiphilic compounds Cz-C-n containing crown ether increases with the length of alkyl chains, similar to that of carbazole compounds with long alkyl chains.展开更多
At first sight, the choice of a socially best economic policy and the choice of an optimal engineering design seem to be quite separate issues. A closer look, however, shows that both approaches which aim at generatin...At first sight, the choice of a socially best economic policy and the choice of an optimal engineering design seem to be quite separate issues. A closer look, however, shows that both approaches which aim at generating a (set of) best alternative(s) have much in common. We describe and characterize axiomatically an aggregation method that uses a set of evaluations that are arranged on a common scale. This scale establishes a common language, so to speak, which conforms to the criteria that are deemed relevant in order to compare various design options. Two conditions are able to characterize the proposed aggregation mechanism. One is a simple dominance requirement, and the other called cancellation independence makes use of the fact that for any pair of objects, rank differences of opposite sign can be reduced without changing the aggregate outcome of the ranking procedure. The proposed method has its origin in voting theory but may have the potential to prove useful in engineering design as well.展开更多
The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry.In this paper,the aggregating process was simulated with offlattice...The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry.In this paper,the aggregating process was simulated with offlattice diffusion-limited cluster-cluster aggregation(DLCA)Monte Carlo programs.The self-similar fractal structures of aggregates have been clearly demonstrated by the statistical analysis of gyration radius distribution and the existence of a scaling distribution of the reduced cluster size.The fractal dimension determined from the relationship between mass and gyration radius of aggregates was 1.80 or so.The fractal dimension of the aggregates drawn from the radial distribution function and structure factor of a single aggregate is about 1.90-2.10.It was also showed that,along with the increasing of particle volume fraction,the fractal dimension will increase in a nearly square root manner,and the spatial range of the fractal structure appearing becomes narrower.Also,the gelation transition can only occur in a particle suspension system where the particle volume fraction is greater than a critical value.展开更多
Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et a...Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et al.,2022).This molecular event is believed to lead to activation of stress pathways ultimately resulting in cellular dysfunction(Eldeeb et al.,2022).Accordingly,many lines of research investigations focused on dampening the formation of protein aggregates or augmenting the clearance of protein aggregates as a potential therapeutic strategy to counteract the progression of neurodegenerative diseases,albeit with little success(Costa-Mattioli and Walter,2020).Cell stress cues such as the accumulation of protein aggregates lead to the activation of stress response pathways that aid cells in responding to the damage.Despite the notion that the transient activation of these pathways helps cells cope with stressors,persistent activation can induce unwanted apoptosis of cells and reduce overall tissue strength as well as lead to an accumulation of aggregation-prone proteins(Hetz and Papa,2018).Mutations in proteins involved in stress signaling termination can cause conditions like ataxia and early-onset dementia(Conroy et al.,2014).Therefore,it is crucial for stress response signaling to be turned off once conditions have improved.Nevertheless,the mechanisms by which cells silence these signals are still elusive.展开更多
We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-gener...We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.展开更多
Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of re...Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.展开更多
Neuroinflammation is a key process in the pathogenesis of various neurodegenerative diseases,such as multiple sclerosis(MS),Alzheimer's disease,and traumatic brain injury.Even for disorders historically unrelated ...Neuroinflammation is a key process in the pathogenesis of various neurodegenerative diseases,such as multiple sclerosis(MS),Alzheimer's disease,and traumatic brain injury.Even for disorders historically unrelated to neuroinflammation,such as Alzheimer's disease,it is now shown to precede pathological protein aggregations.展开更多
Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unco...Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unconventional secretion pathways,focusing on secretory autophagy and its role in secreting protein aggregates associated with neurodegenerative disorders.We also explore additional neuronal functions of secretory autophagy beyond the release of protein aggregates.We propose autophagosomes as transport organelles that deliver cargo material directly from the endoplasmatic reticulum(ER)to the plasma membrane rather than solely to lysosomes.展开更多
The kinetics of the hydrolysis of p-nitrophenyl esters of three types of single-chain carbo- xylic acids, namely, saturated, olefinic and acetylenic, was investigated in two aquiorgano binary sol- vent systems, DMSO-H...The kinetics of the hydrolysis of p-nitrophenyl esters of three types of single-chain carbo- xylic acids, namely, saturated, olefinic and acetylenic, was investigated in two aquiorgano binary sol- vent systems, DMSO-H_2O and dioxane (DX)-H_2O. The ester probes used are: octanoie (C8), do- decanoic (C12), stearic (C18), oleic (C18-ol), elaidic (C18-el) and stearolic (C18-st). The order of measured CAgC values is: C18-ol>C18-el>C18>C18-st, whereas the order of decreasing magnitude of the observed hydrolytic rate constants of the monomeric species (km) is: C18 >C18-el>C18-ol> C18-st. These rather unanticipated results are discussed.展开更多
Four new amphiphilic molecules, i.e., the bolaamphiphiles n-trimethylamino n-hexadecanoate (deAgr 16), n-dodecanoate (deAgr 12), n-undecanoate (deAgr 11), and n-octanoate (deAgr 8) were synthesized. Their ability as d...Four new amphiphilic molecules, i.e., the bolaamphiphiles n-trimethylamino n-hexadecanoate (deAgr 16), n-dodecanoate (deAgr 12), n-undecanoate (deAgr 11), and n-octanoate (deAgr 8) were synthesized. Their ability as deaggregators to break up the aggregating systems of hexadecyl β-naphthoate (A16) and dodecyl β-naphthoate (A12) in dioxanewater binary solvent systems was investigated in a number of solvent systems and at different A16 and A12 concentrations. The results reveal that this new type of bolaamphiphilic molecules appears to be one of the most efficient deaggregators reported, which, at very low concentrations, can effectively break up the aggregating systems of highly concentrated A16 and A12. It is also found that bolaamphiphfles with longer aliphatic chains possess greater deaggregating ability. However, when the overall concentrations of A16 and A12 are very low but still above their critical aggregating concentration, these bolaamphiphilic molecules lose their deaggregating power and tend to coaggregate with the aggregated A16 or A12 molecules. The quite efficient deaggregating ability of the long-chain bolaamphiphfles (deAgr 16 and deAgr 12), as compared to the short-chain deAgr 8, has been ascribed to their dynamic switch-on/switch-off behavior involving coiled-up and uncoiled conformations of their long aliphatic chains.展开更多
With the development of wind energy,it is necessary to develop equivalent models to represent dynamic behaviors of wind farms in power systems.The equivalent wind method is investigated for the aggregation of doubly-f...With the development of wind energy,it is necessary to develop equivalent models to represent dynamic behaviors of wind farms in power systems.The equivalent wind method is investigated for the aggregation of doubly-fed induction generator wind turbines.The detailed procedures for the calculation of equivalent wind are analyzed.The necessity of classifying incoming winds is shown.To improve the performances of the method,incoming winds are classified according to mean wind speeds and positive/negative semi-variances of wind speeds,and a group of turbines with similar incoming winds are aggregated together.The effectiveness of the method is verified through simulations in MATLAB/Simulink.展开更多
With k_8/k_(16), the ratio of the hydrolytic rate-constants of p-nitrophenyl octanoate (C8) to hexadecanoate (C16), as the indicator of the degree of aggregation, the linear dependence of the deg- ree of aggregation o...With k_8/k_(16), the ratio of the hydrolytic rate-constants of p-nitrophenyl octanoate (C8) to hexadecanoate (C16), as the indicator of the degree of aggregation, the linear dependence of the deg- ree of aggregation on solvent aggregating power (SAgP) has been established in five aquiorgano sol- vents, each within a certain range of volume fraction ( values) of the organic cosolvent. The mea- ning of this linearity has been discussed.展开更多
Hydr hobie一lipophilic interactions(HLI)will start to bri about the formationof simple aggregates(Ag,s)and eoa egates(CoAg,s)from neutral organie moleeuleswhich possess at least onefl ble chain with more than seven eH...Hydr hobie一lipophilic interactions(HLI)will start to bri about the formationof simple aggregates(Ag,s)and eoa egates(CoAg,s)from neutral organie moleeuleswhich possess at least onefl ble chain with more than seven eHZ grou ,1,2 at theeritieala egate eoncentration展开更多
文摘We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners＇ cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.
基金The National Natural Science Foundation of China(No.71171048)
文摘The maximal entropy ordered weighted averaging （ME-OWA） operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the methods for aggregating metasearch engine results are divided into two kinds. One has a unique solution, and the other has multiple solutions. The proposed method not only has crisp weights, but also provides multiple aggregation results for decision makers to choose from. In order to prove the application of the ME-OWA operator method, under the context of aggregating metasearch engine results, an example is given, which shows the results obtained by the ME-OWA operator method and the minimax linear programming （ minimax-LP ） method. Comparison between these two methods are also made. The results show that the ME-OWA operator has nearly the same aggregation results as those of the minimax-LP method.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2002AA601170)the National Natural Science Foundation of China (No. 30623001)
文摘Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation gene （opd） into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, Pp,bA. From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25~C, the whole-cell activities of the transgenic Anabaena and Nostoc strains were 0.163~0.001 and 0.289~0.042 unit/gg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites.
文摘The coaggregating behavior of the cationic kinetic probe P16;with different types of surfactants are in complete agreement with predictions based on the newly proposed ESAg concept.
文摘Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the methods which have been used to enhance sustainable exploitation of fisheries resources is the use of Fish Aggregating Devices (FADs). The study was conducted in two areas along the Kenyan coast which are: Msambweni in the southern part and Kuruwitu (Vipingo) in the northern part of the Kenyan coast. A combination of systematic site surveys: structured and semi structured interviews with key informants (community leaders and resource users);participant observations;descriptions of daily and seasonal time use;and analyses of secondary sources, such as fisheries records, was used to gather information and triangulate results. The perception of the community about FADs was determined by conducting a socio-economic survey before and after deploying FADs. Colonization and biomass survey around the deployed FADs was undertaken and fish associated with FADs was recorded. Results indicate that nine families of fish aggregated around FADs and at different distances. Catch and effort at FADs have been evaluated by monitoring catch data from fishers on daily basis after deployments.
基金Project 50674103 supported by the National Natural Science Foundation of China
文摘The influence on fine particle aggregation and flotation behavior induced by high intensity conditioning(HIC) from saturated of the slurry with CO2 saturation was investigated.Bubble size measurements were conducted.The effect of dissolved gas,xanthate addition and agitation speed on fine sphalerite particle aggregation-and flotation-behavior were studied.The results show that during HIC in air or CO2 saturated water xanthate acts as a frother.The dissolved gas content in the pulp and HIC play a synergistic role in promoting fine particle aggregation and hence flotation;a significantly enhanced aggregation of fine sphalerite particles in a CO2 saturated slurry by HIC is observed.The aggregate size increased when the agitation speed was increased from 700 r/min to 1500 r/min.Increasing the HIC speed to 1500 r/min caused a positive impact on flotation kinetics.Further increasing the speed to 2000 r/min resulted in an adverse effect on flotation kinetics.
基金We thank the National Natural Science Foundation of China. The foundation of the Ministry of Science and Technology of China (grant No. G2000078104 and No. G2000077502) for financial supports.
文摘The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amphiphilic compounds Cz-C-n containing crown ether increases with the length of alkyl chains, similar to that of carbazole compounds with long alkyl chains.
文摘At first sight, the choice of a socially best economic policy and the choice of an optimal engineering design seem to be quite separate issues. A closer look, however, shows that both approaches which aim at generating a (set of) best alternative(s) have much in common. We describe and characterize axiomatically an aggregation method that uses a set of evaluations that are arranged on a common scale. This scale establishes a common language, so to speak, which conforms to the criteria that are deemed relevant in order to compare various design options. Two conditions are able to characterize the proposed aggregation mechanism. One is a simple dominance requirement, and the other called cancellation independence makes use of the fact that for any pair of objects, rank differences of opposite sign can be reduced without changing the aggregate outcome of the ranking procedure. The proposed method has its origin in voting theory but may have the potential to prove useful in engineering design as well.
基金the Foundation of Key Laboratory of National Defense Science and Technology of Plasma Physics,China(No.9140C6806020707)the Foundation of China Academy of Engineering Physics(No.2007B08008)for the support.
文摘The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry.In this paper,the aggregating process was simulated with offlattice diffusion-limited cluster-cluster aggregation(DLCA)Monte Carlo programs.The self-similar fractal structures of aggregates have been clearly demonstrated by the statistical analysis of gyration radius distribution and the existence of a scaling distribution of the reduced cluster size.The fractal dimension determined from the relationship between mass and gyration radius of aggregates was 1.80 or so.The fractal dimension of the aggregates drawn from the radial distribution function and structure factor of a single aggregate is about 1.90-2.10.It was also showed that,along with the increasing of particle volume fraction,the fractal dimension will increase in a nearly square root manner,and the spatial range of the fractal structure appearing becomes narrower.Also,the gelation transition can only occur in a particle suspension system where the particle volume fraction is greater than a critical value.
文摘Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et al.,2022).This molecular event is believed to lead to activation of stress pathways ultimately resulting in cellular dysfunction(Eldeeb et al.,2022).Accordingly,many lines of research investigations focused on dampening the formation of protein aggregates or augmenting the clearance of protein aggregates as a potential therapeutic strategy to counteract the progression of neurodegenerative diseases,albeit with little success(Costa-Mattioli and Walter,2020).Cell stress cues such as the accumulation of protein aggregates lead to the activation of stress response pathways that aid cells in responding to the damage.Despite the notion that the transient activation of these pathways helps cells cope with stressors,persistent activation can induce unwanted apoptosis of cells and reduce overall tissue strength as well as lead to an accumulation of aggregation-prone proteins(Hetz and Papa,2018).Mutations in proteins involved in stress signaling termination can cause conditions like ataxia and early-onset dementia(Conroy et al.,2014).Therefore,it is crucial for stress response signaling to be turned off once conditions have improved.Nevertheless,the mechanisms by which cells silence these signals are still elusive.
基金Funded by the Natural Science Foundation of Jiangsu Province(No.BK20220626)the National Natural Science Foundation of China(No.52078068)+2 种基金Science and Technology Innovation Foundation of NIT(No.KCTD006)Jiangsu Marine Structure Service Performance Improvement Engineering Research CenterKey Laboratory of Jiangsu"Marine Floating Wind Power Technology and Equipment"。
文摘We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.
基金Funded by Natural Science Foundation of Guangxi(No.2025GXNSFBA069565)Guangxi Science and Technology Program(No.AD25069101)Guangxi Bagui Scholars Fund。
文摘Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.
基金supported by FWO(Fonds voor Wetenschappelijk Onderzoek),grant number G07562NFWO(to BB)。
文摘Neuroinflammation is a key process in the pathogenesis of various neurodegenerative diseases,such as multiple sclerosis(MS),Alzheimer's disease,and traumatic brain injury.Even for disorders historically unrelated to neuroinflammation,such as Alzheimer's disease,it is now shown to precede pathological protein aggregations.
基金supported by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)grant LU 2347/3-1(to PL).
文摘Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unconventional secretion pathways,focusing on secretory autophagy and its role in secreting protein aggregates associated with neurodegenerative disorders.We also explore additional neuronal functions of secretory autophagy beyond the release of protein aggregates.We propose autophagosomes as transport organelles that deliver cargo material directly from the endoplasmatic reticulum(ER)to the plasma membrane rather than solely to lysosomes.
基金Project supported by the National Natural Science Foundation of China.
文摘The kinetics of the hydrolysis of p-nitrophenyl esters of three types of single-chain carbo- xylic acids, namely, saturated, olefinic and acetylenic, was investigated in two aquiorgano binary sol- vent systems, DMSO-H_2O and dioxane (DX)-H_2O. The ester probes used are: octanoie (C8), do- decanoic (C12), stearic (C18), oleic (C18-ol), elaidic (C18-el) and stearolic (C18-st). The order of measured CAgC values is: C18-ol>C18-el>C18>C18-st, whereas the order of decreasing magnitude of the observed hydrolytic rate constants of the monomeric species (km) is: C18 >C18-el>C18-ol> C18-st. These rather unanticipated results are discussed.
基金NSFC (No .2 9832 0 40 )andStateKeyProjectofFundamentalResearch (No .G2 0 0 0 0 7810 1)
文摘Four new amphiphilic molecules, i.e., the bolaamphiphiles n-trimethylamino n-hexadecanoate (deAgr 16), n-dodecanoate (deAgr 12), n-undecanoate (deAgr 11), and n-octanoate (deAgr 8) were synthesized. Their ability as deaggregators to break up the aggregating systems of hexadecyl β-naphthoate (A16) and dodecyl β-naphthoate (A12) in dioxanewater binary solvent systems was investigated in a number of solvent systems and at different A16 and A12 concentrations. The results reveal that this new type of bolaamphiphilic molecules appears to be one of the most efficient deaggregators reported, which, at very low concentrations, can effectively break up the aggregating systems of highly concentrated A16 and A12. It is also found that bolaamphiphfles with longer aliphatic chains possess greater deaggregating ability. However, when the overall concentrations of A16 and A12 are very low but still above their critical aggregating concentration, these bolaamphiphilic molecules lose their deaggregating power and tend to coaggregate with the aggregated A16 or A12 molecules. The quite efficient deaggregating ability of the long-chain bolaamphiphfles (deAgr 16 and deAgr 12), as compared to the short-chain deAgr 8, has been ascribed to their dynamic switch-on/switch-off behavior involving coiled-up and uncoiled conformations of their long aliphatic chains.
基金This study was supported by Science Founda-tion of Jiangsu Province(No.BK2011137)National Key Technology R&D Program(No.2011BAA07B03)State Grid Corporation of China,2012 research and demonstration project on the key technol-ogies for large scale grid friendly wind farms.
文摘With the development of wind energy,it is necessary to develop equivalent models to represent dynamic behaviors of wind farms in power systems.The equivalent wind method is investigated for the aggregation of doubly-fed induction generator wind turbines.The detailed procedures for the calculation of equivalent wind are analyzed.The necessity of classifying incoming winds is shown.To improve the performances of the method,incoming winds are classified according to mean wind speeds and positive/negative semi-variances of wind speeds,and a group of turbines with similar incoming winds are aggregated together.The effectiveness of the method is verified through simulations in MATLAB/Simulink.
基金Project supported by the National Natural Science Foundation of China.
文摘With k_8/k_(16), the ratio of the hydrolytic rate-constants of p-nitrophenyl octanoate (C8) to hexadecanoate (C16), as the indicator of the degree of aggregation, the linear dependence of the deg- ree of aggregation on solvent aggregating power (SAgP) has been established in five aquiorgano sol- vents, each within a certain range of volume fraction ( values) of the organic cosolvent. The mea- ning of this linearity has been discussed.
文摘Hydr hobie一lipophilic interactions(HLI)will start to bri about the formationof simple aggregates(Ag,s)and eoa egates(CoAg,s)from neutral organie moleeuleswhich possess at least onefl ble chain with more than seven eHZ grou ,1,2 at theeritieala egate eoncentration
