To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO...To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO_(2)precursor solutions with mass fractions of 0,0.2%,0.5%,1.0%,and 3.0%;and Fe_(2)O_(3)-SiO_(2)composite aerogels were fabricated using CO_(2)supercritical drying technology.The effects of the Fe_(2)O_(3)extra addition on the aerogels were investigated.The results show that:(1)Fe_(2)O_(3)doping does not alter the aerogel morphology;Fe_(2)O_(3)suppresses the mass loss at high temperatures and enhances the high-temperature stability of the composite;(2)below 800℃,the aerogel with 0.5%Fe_(2)O_(3)exhibits the lowest thermal conductivity and the best thermal insulation performance;at 800-1000℃,the aerogel with 1%Fe_(2)O_(3)exhibits the lowest thermal conductivity and a good nanoporous structure;(3)by adjusting the Fe_(2)O_(3)extra addition,composite aerogels suitable for different temperature ranges can be tailored.展开更多
The developing course of refactories for glass furnaces in China is reviewed.Suggestions on their development trend in trms of improving in anticipation and meeting the requirements of glass industry in maximum degree...The developing course of refactories for glass furnaces in China is reviewed.Suggestions on their development trend in trms of improving in anticipation and meeting the requirements of glass industry in maximum degree are discussed.展开更多
According to The World Alzheimer Report 2023 by Alzheimer’s Disease International(ADI)estimates that 33 to 38.5 million people worldwide suffer from Alzheimer’s Disease(AD).A crucial hallmark associated with this di...According to The World Alzheimer Report 2023 by Alzheimer’s Disease International(ADI)estimates that 33 to 38.5 million people worldwide suffer from Alzheimer’s Disease(AD).A crucial hallmark associated with this disease is associated with the deficiency of the brain neurotransmitter acetylcholine,due to an affected acetylcholinesterase(AChE)activity.Marine organisms synthesize several classes of compounds,some of which exhibit significant AChE inhibition,such as petrosamine,a coloured pyridoacridine alkaloid.The aim of this work was to characterize the activity of petrosamine isolated for the first time from a Brazilian marine sponge,using two neurotoxicity models with aluminium chloride,as exposure to aluminium is associated with the development of neurodegenerative diseases.The in vitro model was based in a neuroblastoma cell line and the in vivo model exploited the potential of zebrafish(Danio rerio)embryos in mimicking hallmarks of AD.To our knowledge,this is the first report on petrosamine’s activity over these parameters,either in vitro or in vivo,in order to characterize its full potential for tackling neurotoxicity.展开更多
Objectives: This research work intends to clarify the role of artificial saliva, in particularly the role of mucin, a salivary protein, on the surface properties and adhesion ability of Candida spp. oral clinical isol...Objectives: This research work intends to clarify the role of artificial saliva, in particularly the role of mucin, a salivary protein, on the surface properties and adhesion ability of Candida spp. oral clinical isolates to abiotic surfaces. Methods: Four oral clinical isolates of Candida spp. were used: two Candida albicans strains (AC;AM) and two Candida parapsilosis strains (AD;AM2). The strains were isolated from patients using oral prosthesis. The microorganisms were cultured in the absence or presence of mucin and artificial saliva, and their adhesion to an abiotic surface (coated with mucin and artificial saliva) was evaluated. Results: The presence of mucin per se onto the abiotic surface decreased the adhesion of all strains, although the combination of mucin with artificial saliva had reduced this effect. No direct correlation between adhesion and the surface free energies of adhesion of the microorganisms was found. Significance: Candida spp. were human commensal microorganisms that became pathogenic when the host immune defenses were compromised. Medical devices were colonized by Candida spp. particularly, oral prostheses, which might lead to the degradation of the prostheses and systemic infections. The salivary secretions that constantly cover the oral cavity influenced Candida spp. adhesion process. Therefore, it was important to understand the interactions between Candida spp., salivary proteins and the characteristic of oral prosthesis when developing materials for oral prostheses.展开更多
Contact Lens(CLs)are often disposed of via toilet or sinks,ending up in the wastewater treatment plants(WWTPs).Millions of CLs enter WWTPs worldwide each year in macro and micro sizes.Despite WWTPs'ability to remo...Contact Lens(CLs)are often disposed of via toilet or sinks,ending up in the wastewater treatment plants(WWTPs).Millions of CLs enter WWTPs worldwide each year in macro and micro sizes.Despite WWTPs'ability to remove solids,CLs can persist and potentially contaminate watercourses and soils.This study evaluates whether different CLs degrade in WWTP aeration tanks.Six daily CLs(Nelfilcon A,Delefilcon A,Nesofilcon A,Stenfilcon A,Narafilcon A,Somofilcon A)and four monthly CLs(Lotrafilcon B,Comfilcon A,Senofilcon A,and Samfilcon A)were immersed in aeration tanks for twelve weeks.Their physical and chemical properties,including water content(WC),refractive index(RI),chemical prop-erties(Fourier Transform Infrared Spectroscopy),and mechanical properties were assessed.Results show that all CLs maintained their physical appearance after 12 weeks.Neither Nelfilcon A nor Narafilcon A exhibited significant changes in WC and RI,(p>0.05,Tukey test),while other daily lenses showed variations in at least one parameter.Among monthly CLs,only Senofilcon A showed significant differences in both WC(p<0.001,Tukey test)and RI(p<0.0001,Tukey test).No differences in Young's modulus were observed for any lenses(p>0.05 Tukey test).However,Somofilcon A displayed significant changes in stress at break(p<0.0001,Tukey test),and Elongation at Break(p<0.05,Tukey test).No changes were found in the chemical structure of any CLs suggesting that twelve weeks in WWTP aeration tanks is insufficient for CLs degradation.These findings highlight CLs as a potential emerging pollutant,emphasizing their persis-tence in sludge or migration into watercourses and soils.展开更多
Microbial decomposers,especially a fungal group called aquatic hyphomycetes,play a critical role in processing plant litter in freshwaters by increasing its palatability to invertebrate shredders.Traditionally,communi...Microbial decomposers,especially a fungal group called aquatic hyphomycetes,play a critical role in processing plant litter in freshwaters by increasing its palatability to invertebrate shredders.Traditionally,communities of aquatic hyphomycetes have been assessed through the identification of spores,which misses non-sporulating taxa.Among new technologies,454 pyrosequencing stands out as most promising for large-scale species identification.However,very few attempts have been made to validate its effectiveness for assessing the diversity of stream-dwelling fungal communities.We attempted to gain greater insight into the diversity of aquatic fungal communities in streams exposed to various degrees of eutrophication by using the 454 pyrosequencing technology.A total of 173,889 ITS2 pyrosequencing reads with hits for fungi were obtained from the 5 investigated streams.The majority of operational taxonomic units(OTUs)belonged to Ascomycota and the identification to the genus level was achieved for 169 OTUs.Of the total,135,257 reads(ca.78%)showed close affinities to aquatic hyphomycete species.Pyrosequencing showed declining fungal diversity in the most eutrophic streams,which was congruent with a reduced diversity found through spore identification.Dominance patterns revealed by connecting representative OTUs to ITS sequences from aquatic hyphomycetes were similar to those determined by traditional spore identification techniques.However,454 pyrosequencing provided a more comprehensive view of fungal diversity;it captured almost twice as many taxa as spore counts.This study vali-dates the effectiveness of 454 pyrosequencing for surveying the diversity of stream-dwelling fungal decomposer communities.Its application may accelerate the use of these communities for monitoring the integrity of freshwaters.展开更多
文摘To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO_(2)precursor solutions with mass fractions of 0,0.2%,0.5%,1.0%,and 3.0%;and Fe_(2)O_(3)-SiO_(2)composite aerogels were fabricated using CO_(2)supercritical drying technology.The effects of the Fe_(2)O_(3)extra addition on the aerogels were investigated.The results show that:(1)Fe_(2)O_(3)doping does not alter the aerogel morphology;Fe_(2)O_(3)suppresses the mass loss at high temperatures and enhances the high-temperature stability of the composite;(2)below 800℃,the aerogel with 0.5%Fe_(2)O_(3)exhibits the lowest thermal conductivity and the best thermal insulation performance;at 800-1000℃,the aerogel with 1%Fe_(2)O_(3)exhibits the lowest thermal conductivity and a good nanoporous structure;(3)by adjusting the Fe_(2)O_(3)extra addition,composite aerogels suitable for different temperature ranges can be tailored.
文摘The developing course of refactories for glass furnaces in China is reviewed.Suggestions on their development trend in trms of improving in anticipation and meeting the requirements of glass industry in maximum degree are discussed.
基金supported by the“Contrato-Programa”UIDB/04050/2020 funded by national funds through the FCT I.P.https://doi.org/https://doi.org/10.54499/UIDB/04050/2020.MF(SFRH/BD/147819/2019)holds a scholarship from FCTFUNCAP-INTERNACIONALIZAÇÃO(Grant ITR-0214-00060.01.00/23)CNPq-Universal(Grant 406119/2021-0).
文摘According to The World Alzheimer Report 2023 by Alzheimer’s Disease International(ADI)estimates that 33 to 38.5 million people worldwide suffer from Alzheimer’s Disease(AD).A crucial hallmark associated with this disease is associated with the deficiency of the brain neurotransmitter acetylcholine,due to an affected acetylcholinesterase(AChE)activity.Marine organisms synthesize several classes of compounds,some of which exhibit significant AChE inhibition,such as petrosamine,a coloured pyridoacridine alkaloid.The aim of this work was to characterize the activity of petrosamine isolated for the first time from a Brazilian marine sponge,using two neurotoxicity models with aluminium chloride,as exposure to aluminium is associated with the development of neurodegenerative diseases.The in vitro model was based in a neuroblastoma cell line and the in vivo model exploited the potential of zebrafish(Danio rerio)embryos in mimicking hallmarks of AD.To our knowledge,this is the first report on petrosamine’s activity over these parameters,either in vitro or in vivo,in order to characterize its full potential for tackling neurotoxicity.
文摘Objectives: This research work intends to clarify the role of artificial saliva, in particularly the role of mucin, a salivary protein, on the surface properties and adhesion ability of Candida spp. oral clinical isolates to abiotic surfaces. Methods: Four oral clinical isolates of Candida spp. were used: two Candida albicans strains (AC;AM) and two Candida parapsilosis strains (AD;AM2). The strains were isolated from patients using oral prosthesis. The microorganisms were cultured in the absence or presence of mucin and artificial saliva, and their adhesion to an abiotic surface (coated with mucin and artificial saliva) was evaluated. Results: The presence of mucin per se onto the abiotic surface decreased the adhesion of all strains, although the combination of mucin with artificial saliva had reduced this effect. No direct correlation between adhesion and the surface free energies of adhesion of the microorganisms was found. Significance: Candida spp. were human commensal microorganisms that became pathogenic when the host immune defenses were compromised. Medical devices were colonized by Candida spp. particularly, oral prostheses, which might lead to the degradation of the prostheses and systemic infections. The salivary secretions that constantly cover the oral cavity influenced Candida spp. adhesion process. Therefore, it was important to understand the interactions between Candida spp., salivary proteins and the characteristic of oral prosthesis when developing materials for oral prostheses.
基金supported by the Portuguese Foundation for Science and Technology(FCT)in the framework of the Strategic Funding UIDB/04650/2020,as well as by the FCT grant 2021.07082.BD.
文摘Contact Lens(CLs)are often disposed of via toilet or sinks,ending up in the wastewater treatment plants(WWTPs).Millions of CLs enter WWTPs worldwide each year in macro and micro sizes.Despite WWTPs'ability to remove solids,CLs can persist and potentially contaminate watercourses and soils.This study evaluates whether different CLs degrade in WWTP aeration tanks.Six daily CLs(Nelfilcon A,Delefilcon A,Nesofilcon A,Stenfilcon A,Narafilcon A,Somofilcon A)and four monthly CLs(Lotrafilcon B,Comfilcon A,Senofilcon A,and Samfilcon A)were immersed in aeration tanks for twelve weeks.Their physical and chemical properties,including water content(WC),refractive index(RI),chemical prop-erties(Fourier Transform Infrared Spectroscopy),and mechanical properties were assessed.Results show that all CLs maintained their physical appearance after 12 weeks.Neither Nelfilcon A nor Narafilcon A exhibited significant changes in WC and RI,(p>0.05,Tukey test),while other daily lenses showed variations in at least one parameter.Among monthly CLs,only Senofilcon A showed significant differences in both WC(p<0.001,Tukey test)and RI(p<0.0001,Tukey test).No differences in Young's modulus were observed for any lenses(p>0.05 Tukey test).However,Somofilcon A displayed significant changes in stress at break(p<0.0001,Tukey test),and Elongation at Break(p<0.05,Tukey test).No changes were found in the chemical structure of any CLs suggesting that twelve weeks in WWTP aeration tanks is insufficient for CLs degradation.These findings highlight CLs as a potential emerging pollutant,emphasizing their persis-tence in sludge or migration into watercourses and soils.
基金Fund–Operational Competitiveness Programme(FEDER-POFC-COMPETE)(FCOMP-01-0124-FEDER-013954)the Portuguese Foundation for Science and Technology supported this study(PEst-OE/BIA/UI4050/2014 and PTDC/AACAMB/113746/2009)S.Duarte(SFRH/BPD/47574/2008).
文摘Microbial decomposers,especially a fungal group called aquatic hyphomycetes,play a critical role in processing plant litter in freshwaters by increasing its palatability to invertebrate shredders.Traditionally,communities of aquatic hyphomycetes have been assessed through the identification of spores,which misses non-sporulating taxa.Among new technologies,454 pyrosequencing stands out as most promising for large-scale species identification.However,very few attempts have been made to validate its effectiveness for assessing the diversity of stream-dwelling fungal communities.We attempted to gain greater insight into the diversity of aquatic fungal communities in streams exposed to various degrees of eutrophication by using the 454 pyrosequencing technology.A total of 173,889 ITS2 pyrosequencing reads with hits for fungi were obtained from the 5 investigated streams.The majority of operational taxonomic units(OTUs)belonged to Ascomycota and the identification to the genus level was achieved for 169 OTUs.Of the total,135,257 reads(ca.78%)showed close affinities to aquatic hyphomycete species.Pyrosequencing showed declining fungal diversity in the most eutrophic streams,which was congruent with a reduced diversity found through spore identification.Dominance patterns revealed by connecting representative OTUs to ITS sequences from aquatic hyphomycetes were similar to those determined by traditional spore identification techniques.However,454 pyrosequencing provided a more comprehensive view of fungal diversity;it captured almost twice as many taxa as spore counts.This study vali-dates the effectiveness of 454 pyrosequencing for surveying the diversity of stream-dwelling fungal decomposer communities.Its application may accelerate the use of these communities for monitoring the integrity of freshwaters.
