The cyclone dust collector is an important subsystem of straw crushers used in agriculture.In the present study,a new type of dust collector with involute morphology is proposed to obtain better dust removal efficienc...The cyclone dust collector is an important subsystem of straw crushers used in agriculture.In the present study,a new type of dust collector with involute morphology is proposed to obtain better dust removal efficiency with respect to that of classical tangential and spiral dust collectors.A discrete phase model(DPM)method is used in synergy with a turbulence model,and the SIMPLE algorithm to simulate the flow field inside the dust collector and the related particle dynamics.It is shown that the internal flow field features a primary swirl,a secondary swirl and blockage effects.Moreover,for the involute dust collector,the tangential velocity in the initial stage and the pressure in the high-pressure area are larger than those obtained for the classical types.The dust removal efficiency is 37.11%,25.3%,and 16.37%for the involute type dust collector,the tangential type and the spiral type,respectively.展开更多
BACKGROUND Visual hallucination(VH)refers to a spontaneous visual perception without corresponding external stimuli and often occurs in ophthalmological and neuropsychiatric disorders.It is associated with poor qualit...BACKGROUND Visual hallucination(VH)refers to a spontaneous visual perception without corresponding external stimuli and often occurs in ophthalmological and neuropsychiatric disorders.It is associated with poor quality of life,and increased patient hospitalization and nursing home admission.To date,a scientometric analysis of research on VH is lacking.AIM To objectively summarize the features of VH research and gain insights into the emerging trends in research on VH.METHODS CiteSpace V was used in this article.Publication outputs,document types,geographic distributions,co-authorship status,research hotspots,and co-citation status were analyzed.A total of 2176 original articles and 465 reviews were included in the database downloaded from the Web of Science Core Collection.We selected the top 50 most cited or occurring articles or items to create a visualized network with a 1-year interval.In the document co-citation analysis stage,we performed clustering analysis on co-cited references,and log likelihood tests were used to name the clusters.RESULTS The results showed that most publications can be classified into neurology,sports,and ophthalmology studies.In addition,North America,Europe,Asia and Australia published the most documents.Some well-known authors have always had a leading role in this field;meanwhile,new authors keep emerging.A relatively stable cooperation has been formed among many authors.Furthermore,neuropsychiatric symptom and functional connectivity are the top hotspots.Research on VH in dementia with Lewy bodies and Parkinson’s disease(PD)have received much attention.Studies on VH in PD are likely to be the new emerging trends in the future,especially the mechanisms of VH.CONCLUSION Research on VH has formed a complete system.More large-scale clinical and indepth basic research are required to better understand the mechanisms underlying VH,which will contribute to our understanding of the pathophysiology and therapeutic options for VH.展开更多
Microwave absorbers with unique optical and mechanical performance are urgent for complex electromagnetic environment.Here,we demonstrate the mechanically flexible,optically transparent,and microwave-absorbing polyacr...Microwave absorbers with unique optical and mechanical performance are urgent for complex electromagnetic environment.Here,we demonstrate the mechanically flexible,optically transparent,and microwave-absorbing polyacrylamide(PAM)hydrogel,in which the polar water molecules with high polarization contribute to the efficient microwave attenuation,but the binding between water molecules and PAM will slow down the orientation polarization of polar molecules.Meanwhile,the dominated dielectric property of water molecules in PAM hydrogel determines that the molecules displacement in polymer mixture is feasible for manipulating permittivity.Besides,by decreasing temperature,the flexible and transparent hydrogel will switch to rigid and opaque state as the phase conversion between amorphous and polycrystal state.By constructing structures with such hydrogel,the obtained absorber also exhibits the optical and mechanical switchable properties,covering the effective absorption within 5.7-18 GHz.This work provides an effective method to fabricate optically and mechanically manipulable microwave absorbers for intelligent electromagnetic stealth systems.展开更多
The discovery of biological activities of natural products plays a vital part in drug development.The mechanism by which organisms respond to temperature changes via biosynthesis of natural products remained largely c...The discovery of biological activities of natural products plays a vital part in drug development.The mechanism by which organisms respond to temperature changes via biosynthesis of natural products remained largely cryptic.A thermophilic fungus under cold stress turned black and accumulated a polyketide metabolite 1 and lipid mass.Deficiency in 1 caused melanin loss and accumulated extra lipid mass,unexpectedly leading to seriously damaged mitochondria diagnostic for ferroptosis.Further analysis revealed that lipid mass induced by cold stress intensively increased ferroptosis risk and 1 functioned as cell wall reinforcer against mass lipid accumulation and as reactive oxygen species scavenger against lipid peroxidation.We also found that melanin in mice lowered lipid level but enhanced animal resistance to cold stress.Treatment with melanin precursors significantly increased mouse cell survival rate under cold stress.Our results unveiled a metabolite-lipid-ferroptosis-cold relationship,which provided mechanistic insights into the functions of most common metabolites and into diseases related to cold stress.These findings opened a perspective for developing anti-cold and anti-ferroptosis therapeutics and agents.展开更多
Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental impor...Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental importance in understanding the underlying mechanism of their atmospheric reactions.In sharp contrast to the intensively studied parent molecule(CH_(2)OO)and the alkyl-substituted derivatives,the knowledge about the fluorinated analogue CF_(3)C(H)OO is scarce.By carefully heating the triplet carbene CF_(3)CH in an O2-doped Ar-matrix to 35 K,the elusive carbonyl oxide CF_(3)C(H)OO in syn-and anti-conformations has been generated and characterized with infrared(IR)and ultraviolet-visible(UV-vis)spectroscopy.The spectroscopic identification is supported by^(18)O-labeling experiments and quantum chemical calculations at the B3 LYP/6-311++G(3df,3pd)and MP2/6-311++G(2d,2p)levels.Upon the long-wavelength irradiation(λ>680 nm),both conformers of CF_(3)C(H)OO decompose to give trifluoroacetaldehyde CF_(3)C(H)O and simultaneously rearrange to the isomeric dioxirane,cyclic-CF_(3)CH(OO),which undergoes isomerization to the lowest-energy carboxylic acid CF_(3)C(O)OH upon UV-light excitation at 365 nm.The O_(2)-oxidation of CF_(3)CH via the intermediacy of CF_(3)C(H)OO and cyclic-CF_(3)CH(OO)might provide new insight into the mechanism for the degradation of hydro-chlorofluorocarbon CF_(3)CHCl_(2)(HCFC-123)in the atmosphere.展开更多
基金supported by the Independent Research Fund of the State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines(No.SKLMRDPC20ZZ06)and the Program in the Youth Elite Support Plan in Universities of Anhui Province(No.gxyq2020013).
文摘The cyclone dust collector is an important subsystem of straw crushers used in agriculture.In the present study,a new type of dust collector with involute morphology is proposed to obtain better dust removal efficiency with respect to that of classical tangential and spiral dust collectors.A discrete phase model(DPM)method is used in synergy with a turbulence model,and the SIMPLE algorithm to simulate the flow field inside the dust collector and the related particle dynamics.It is shown that the internal flow field features a primary swirl,a secondary swirl and blockage effects.Moreover,for the involute dust collector,the tangential velocity in the initial stage and the pressure in the high-pressure area are larger than those obtained for the classical types.The dust removal efficiency is 37.11%,25.3%,and 16.37%for the involute type dust collector,the tangential type and the spiral type,respectively.
基金Supported by National Key Research and Development Program of China,No.2016YFC1306601Special Funds of the Jiangsu Provincial Key Research and Development Program,No.BE2018610 and No.BE2019612+2 种基金Jiangsu Provincial Cadre Health Projects,No.BJ16001 and No.BJ17006Special Funds of the Jiangsu Provincial 333 Highlevel Talent Cultivation ProjectsNanjing Medical Science and Technology Development Foundation,No.ZKX17031 and No.QRX17026.
文摘BACKGROUND Visual hallucination(VH)refers to a spontaneous visual perception without corresponding external stimuli and often occurs in ophthalmological and neuropsychiatric disorders.It is associated with poor quality of life,and increased patient hospitalization and nursing home admission.To date,a scientometric analysis of research on VH is lacking.AIM To objectively summarize the features of VH research and gain insights into the emerging trends in research on VH.METHODS CiteSpace V was used in this article.Publication outputs,document types,geographic distributions,co-authorship status,research hotspots,and co-citation status were analyzed.A total of 2176 original articles and 465 reviews were included in the database downloaded from the Web of Science Core Collection.We selected the top 50 most cited or occurring articles or items to create a visualized network with a 1-year interval.In the document co-citation analysis stage,we performed clustering analysis on co-cited references,and log likelihood tests were used to name the clusters.RESULTS The results showed that most publications can be classified into neurology,sports,and ophthalmology studies.In addition,North America,Europe,Asia and Australia published the most documents.Some well-known authors have always had a leading role in this field;meanwhile,new authors keep emerging.A relatively stable cooperation has been formed among many authors.Furthermore,neuropsychiatric symptom and functional connectivity are the top hotspots.Research on VH in dementia with Lewy bodies and Parkinson’s disease(PD)have received much attention.Studies on VH in PD are likely to be the new emerging trends in the future,especially the mechanisms of VH.CONCLUSION Research on VH has formed a complete system.More large-scale clinical and indepth basic research are required to better understand the mechanisms underlying VH,which will contribute to our understanding of the pathophysiology and therapeutic options for VH.
基金This work was financially supported by the National Natural Science Foundation of China(No.62101073)Natural Science Foundation of Hunan Province(Nos.2021JJ30154 and 2022JJ40127)+1 种基金Scientific Research Project of Hunan Provincial Education Department(No.21B0557)Development and Reform Commission of Hunan Province 2021 Innovative Research and Development Project(No.10:Preparation and Electromagnetic Properties of Biochar Composites).
文摘Microwave absorbers with unique optical and mechanical performance are urgent for complex electromagnetic environment.Here,we demonstrate the mechanically flexible,optically transparent,and microwave-absorbing polyacrylamide(PAM)hydrogel,in which the polar water molecules with high polarization contribute to the efficient microwave attenuation,but the binding between water molecules and PAM will slow down the orientation polarization of polar molecules.Meanwhile,the dominated dielectric property of water molecules in PAM hydrogel determines that the molecules displacement in polymer mixture is feasible for manipulating permittivity.Besides,by decreasing temperature,the flexible and transparent hydrogel will switch to rigid and opaque state as the phase conversion between amorphous and polycrystal state.By constructing structures with such hydrogel,the obtained absorber also exhibits the optical and mechanical switchable properties,covering the effective absorption within 5.7-18 GHz.This work provides an effective method to fabricate optically and mechanically manipulable microwave absorbers for intelligent electromagnetic stealth systems.
基金supported by the National Natural Science Foundation of China(21977086,82260691,and 21867018)“Double tops”from Yunnan Province and Yunnan University(202201BF070001-012)the Yunnan Innovative Research Team for Discovery and Biosynthesis of Bioactive Natural Products(2018HC012)。
文摘The discovery of biological activities of natural products plays a vital part in drug development.The mechanism by which organisms respond to temperature changes via biosynthesis of natural products remained largely cryptic.A thermophilic fungus under cold stress turned black and accumulated a polyketide metabolite 1 and lipid mass.Deficiency in 1 caused melanin loss and accumulated extra lipid mass,unexpectedly leading to seriously damaged mitochondria diagnostic for ferroptosis.Further analysis revealed that lipid mass induced by cold stress intensively increased ferroptosis risk and 1 functioned as cell wall reinforcer against mass lipid accumulation and as reactive oxygen species scavenger against lipid peroxidation.We also found that melanin in mice lowered lipid level but enhanced animal resistance to cold stress.Treatment with melanin precursors significantly increased mouse cell survival rate under cold stress.Our results unveiled a metabolite-lipid-ferroptosis-cold relationship,which provided mechanistic insights into the functions of most common metabolites and into diseases related to cold stress.These findings opened a perspective for developing anti-cold and anti-ferroptosis therapeutics and agents.
基金supported by the National Natural Science Foundation of China(Nos.22003010 and 22025301)
文摘Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental importance in understanding the underlying mechanism of their atmospheric reactions.In sharp contrast to the intensively studied parent molecule(CH_(2)OO)and the alkyl-substituted derivatives,the knowledge about the fluorinated analogue CF_(3)C(H)OO is scarce.By carefully heating the triplet carbene CF_(3)CH in an O2-doped Ar-matrix to 35 K,the elusive carbonyl oxide CF_(3)C(H)OO in syn-and anti-conformations has been generated and characterized with infrared(IR)and ultraviolet-visible(UV-vis)spectroscopy.The spectroscopic identification is supported by^(18)O-labeling experiments and quantum chemical calculations at the B3 LYP/6-311++G(3df,3pd)and MP2/6-311++G(2d,2p)levels.Upon the long-wavelength irradiation(λ>680 nm),both conformers of CF_(3)C(H)OO decompose to give trifluoroacetaldehyde CF_(3)C(H)O and simultaneously rearrange to the isomeric dioxirane,cyclic-CF_(3)CH(OO),which undergoes isomerization to the lowest-energy carboxylic acid CF_(3)C(O)OH upon UV-light excitation at 365 nm.The O_(2)-oxidation of CF_(3)CH via the intermediacy of CF_(3)C(H)OO and cyclic-CF_(3)CH(OO)might provide new insight into the mechanism for the degradation of hydro-chlorofluorocarbon CF_(3)CHCl_(2)(HCFC-123)in the atmosphere.
