We demonstrate a method to realize unidirectional negative refraction in an acoustic parity-time(P T)-symmetric system, which is composed of a pair of metasurfaces sandwiching an air gap. The pair of metasurfaces poss...We demonstrate a method to realize unidirectional negative refraction in an acoustic parity-time(P T)-symmetric system, which is composed of a pair of metasurfaces sandwiching an air gap. The pair of metasurfaces possesses loss and gain modulations. The unidirectional negative refraction, which is strictly limited to the case of incident wave imposing on the loss end of the metasurface, is demonstrated at the exception point(EP) in this P T-symmetric system, while the incidence from the other side leads to strong reflection. Based on rigorous calculations, we explicitly show the underlying mechanism of this model to achieve unidirectional wave scatterings around the EP in the parametric space. In addition, the perfect imaging of a point source in the three-dimensional space, as a signature of negative refraction, is simulated to provide a verification of our work. We envision that this work may sharpen the understanding of P T-symmetric structures and inspire more acoustic functional devices.展开更多
Microsporogenesis and flower development in Eucalyptus urophylla 9 E. grandis were examined using chromosome tableting to provide a method to predict the meiotic stages in this species. Although microsporogenesis was ...Microsporogenesis and flower development in Eucalyptus urophylla 9 E. grandis were examined using chromosome tableting to provide a method to predict the meiotic stages in this species. Although microsporogenesis was normal, cytokinesis during meiosis of pollen mother cells occurred simultaneously, with strong asynchronism observed in the two different lengths of stamens in a flower bud. In a single flower, the developmental period of microsporogenesis in anthers on the longer stamens was always ahead of those on the shorter stamens. Flower development was also asynchronous at different locations on a branch. Flower buds on the upper side of the branch were larger in diameter than those on the lower side. In addition,a correlation was observed between microsporogenesisdevelopment and flower bud diameter growth. The pachytene stage was first observed when the diameter of the flower buds increased to 3.0 mm, and the majority of the meiotic stages were observed when bud diameters ranged from 3.5 to5.0 mm. This study showed that the developmental stages of microsporogenesis in Eucalyptus urophylla 9 E. grandis could be distinguished readily, which may be applicable to future breeding studies.展开更多
BACKGROUND The incidence and prevalence of atrial fibrillation are increasing each year,and this condition is one of the most common clinical arrhythmias.AIM To investigate the levels and significance of serum fibrobl...BACKGROUND The incidence and prevalence of atrial fibrillation are increasing each year,and this condition is one of the most common clinical arrhythmias.AIM To investigate the levels and significance of serum fibroblast growth factor 23(FGF-23)and miR-208 b in patients with atrial fibrillation and their relationship with prognosis.METHODS From May 2018 to October 2019,240 patients with atrial fibrillation were selected as an observation group,including 134 with paroxysmal atrial fibrillation and 106 with persistent atrial fibrillation;150 patients with healthy sinus rhythm were selected as a control group.The serum levels of FGF-23 and miR-208 b in the two groups were measured.In the observation group,cardiac parameters were determined by echocardiography.RESULTS The serum levels of FGF-23 and miR-208 b in the observation group were 210.20±89.60 ng/mL and 5.30±1.22 ng/mL,which were significantly higher than the corresponding values in the control group(P<0.05).In the observation group,the serum levels of FGF-23 and miR-208 b in patients with persistent atrial fibrillation were 234.22±70.05 ng/mL and 5.83±1.00 ng/mL,which were significantly higher than the corresponding values in patients with paroxysmal atrial fibrillation(P<0.05).The left atrial dimension(LAD)of patients with persistent atrial fibrillation was 38.81±5.11 mm,which was significantly higher than that of patients with paroxysmal atrial fibrillation(P>0.05).The serum levels of FGF-23and miR-208 b were positively correlated with the LAD(r=0.411 and 0.382,P<0.05).In the observation group,the serum levels of FGF-23 and miR-208 b in patients with a major cardiovascular event(MACE)were 243.30±72.29 ng/mL and 6.12±1.12 ng/mL,which were significantly higher than the corresponding values in patients without a MACE(P<0.05).CONCLUSION The serum levels of FGF-23 and miR-208 b are increased in patients with atrial fibrillation and are related to the type of disease,cardiac parameters,and prognosis.展开更多
Previous reports have suggested that Ang-(1-7)may have a protective effect in endothelial cells against high glucose(HG)-induced cell injury thanks to a modulatory mechanism in the NF-κB signaling pathway.In this stu...Previous reports have suggested that Ang-(1-7)may have a protective effect in endothelial cells against high glucose(HG)-induced cell injury thanks to a modulatory mechanism in the NF-κB signaling pathway.In this study,we have examined whether NF-κB-IL-1βand Heme oxygenase-1(HO-1)pathways contribute to the protection of Ang-(1-7)against hyperglycemia-induced inflammation and oxidative stress in human umbilical vein endothelial cells(HUVECs).Our results indicate that time-varying exposures of HUVECs,from 1 h to 24 h,to high glucose concentrations result in an increased expression of phosphorylated(p)-p65 and HO-1 in a time-dependent manner.As an inhibitor of NF-κB,pyrrolidinedithiocarbamic acid(PDTC)suppressed IL-1βproduction induced by HG.Of note,HUVECs previously treated with Ang-(1-7)(2μM)for 30 min before being exposed to HG concentrations significantly ameliorated the HG-increased in p-p65 and IL-1βexpression;whereas obviously up-regulated the level of HO-1,along with inhibition of oxidative stress,inflammation,and the HG-induced cytotoxicity.Importantly,when HUVECs were previously treated either with PDTC or IL-1Ra for 30 min before being exposed to HG,it significantly prevented damages caused by high glucose concentrations mentioned above,while the treatment of HO-1 inhibitor Sn-protoporphyrin(SnPP)before exposure to both HG and Ang-(1-7)significantly blocked the protective effect exerted by Ang-(1-7)on endothelial cells against injuries induced by HG mentioned above.To conclude,the data of this study showed that activation and inhibition of the NF-κB-IL-1βpathway and HO-1 pathway may constitute an important defense mechanism against endothelial cell damage caused by HG concentrations.We additionally gave new evidence showing that exogenous Ang-(1-7)exerts a protective effect on HUVECs against the HG-induced cell injury via the inhibition and the activation of the NF-κB-IL-1βpathway and the HO-1 pathway,respectively.展开更多
Objective: To study the effects of serum Fractalkine on vascular remodeling and oxidative stress activation in patients with COPD complicated by pulmonary heart disease. Methods:Patients who were hospitalized in Chong...Objective: To study the effects of serum Fractalkine on vascular remodeling and oxidative stress activation in patients with COPD complicated by pulmonary heart disease. Methods:Patients who were hospitalized in Chongqing Armed Corps Police Hospital due to COPD between June 2014 and April 2017 were selected, the patients with COPD alone were included in COPD group, and the patients with COPD complicated by pulmonary heart disease were included in COPD+PHD group;healthy volunteers who underwent physical examination during the same period were selected as the control group of the study. The serum was collected to determine the contents of Fractalkine, vascular remodeling indexes and oxidative stress indexes. Results: Serum Fractalkine, ANG-2, MMP2, MMP9, VEGF, FGF2, Nogo-B, ET-1 and MDA contents of COPD+PHD group and COPD group were higher than those of control group whereas T-AOC contents were lower than that of control group;serum Fractalkine, ANG-2, MMP2, MMP9, VEGF, FGF2, Nogo-B, ET-1 and MDA contents of COPD+PHD group were higher than those of COPD group whereas T-AOC content was lower than that of COPD group. Serum ANG-2, MMP2, MMP9, VEGF, FGF2, Nogo-B, ET-1 and MDA contents of COPD+PHD group of patients with high Fractalkine content were significantly higher than those of COPD+PHD group of patients with low Fractalkine content whereas T-AOC content was lower than that of COPD+PHD group of patients with low Fractalkine content. Conclusion: The increase of serum Fractalkine in patients with COPD complicated by pulmonary heart disease can aggravate the vascular remodeling and promote the oxidative stress activation.展开更多
The wide application of CdSe quantum dots(QDs)increases its stress risk to sewage treatment systems.This study evaluated the response of nitrification performance,floc characteristics and microbial community of nitrif...The wide application of CdSe quantum dots(QDs)increases its stress risk to sewage treatment systems.This study evaluated the response of nitrification performance,floc characteristics and microbial community of nitrifying sludge under long-term exposure to CdSe QDs.Results showed CdSe QDs(≥1 mg/L)would decrease the activity of ammonia monooxygenase(AMO).Under the stress of 30 mg/L CdSe QDs,the activity of AMO was reduced by 66%,while the activities of hydroxylamine oxidase and nitrite oxidoreductase were enhanced by 19.1%and 26%,respectively.Thus,the final nitrification effects were not adversely affected,and the production rates of NO_(2)^(-)-N and NO_(3)^(-)-N were accelerated.Additionally,CdSe QDs improved biomass concentration in sludge and maintained the stability of sludge settleability.High throughput sequencing analysis showed that CdSe QDs evidently reduced the abundance and diversity of microbial community in nitrifying sludge.The abundances of amino acid metabolism and lipid metabolism were enriched.Moreover,CdSe QDs decreased the fluorescence intensity of tryptophan-like protein from 2,326 to 1,179 a.u.in loosely bound extracellular polymeric substances(EPSs)and from 3,792 to 3,117 a.u.in tightly bound EPSs.To relieve CdSe QD stress,the polysaccharide content increased from0.31 to 0.61 mg/g MLSS and intracellular antioxidant defense was activated.With CdSe QD level increasing to 30 mg/L,the total antioxygenic capacity and the activities of catalase were enhanced up to 411%and 143.2%,respectively.Thereby,CdSe QDs had little adverse effects on cell membrane integrity,microbial metabolism and the abundance of Nitrospirae.展开更多
The global problem of petroleum contamination in soils seriously threatens environmental safety and human health.Current studies have successfully demonstrated the feasibility of bioelectrokinetic and bioelectrochemic...The global problem of petroleum contamination in soils seriously threatens environmental safety and human health.Current studies have successfully demonstrated the feasibility of bioelectrokinetic and bioelectrochemical remediation of petroleum-contaminated soils due to their easy implementation,environmental benignity,and enhanced removal efficiency compared to bioremediation.This paper reviewed recent progress and development associated with bioelectrokinetic and bioelectrochemical remediation of petroleum-contaminated soils.The working principles,removal efficiencies,affecting factors,and constraints of the two technologies were thoroughly summarized and discussed.The potentials,challenges,and future perspectives were also deliberated to shed light on how to overcome the barriers and realize widespread implementation on large scales of these two technologies.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-Cov-2)infection,causing CovID-19,is the most challenging pandemic of the modern era.It has resulted in over 5 million deaths worldwide.To quickly explore therapeuti...Severe acute respiratory syndrome coronavirus 2(SARS-Cov-2)infection,causing CovID-19,is the most challenging pandemic of the modern era.It has resulted in over 5 million deaths worldwide.To quickly explore therapeutics for COVID-19,we utilized a previously-established system,namely CEBIT.We performed a highthroughput screening of FDA-approved drugs to inhibit the interaction between the receptor-binding domain(RBD)of SARS-CoV-2 spike protein and its obligate receptor ACE2.This interaction is essential for viral entry and therefore represents a promising therapeutic target.Based on the recruitment of interacting molecules into phase-separated condensates as a readout,we identified six positive candidates from a library of 2572 compounds,most of which have been reported to inhibit the entry of SARs-Cov-2 into host cells.Our surface plasmon resonance(SPR)and molecular docking analyses revealed the possible mechanisms via which these compounds interfere with the interaction between RBD and ACE2.Hence,our results indicate that CEBIT is highly versatile for identifying drugs against SARS-Cov-2 entry,and targeting Cov-2 entry by small molecule drugs is a viable therapeutic option to treat CovID-19 in addition to commonly used monoclonal antibodies.展开更多
基金supported by the National Key R&D Program of China (Grant Nos. 2022YFA1404400 and 2022YFA1404403)the National Natural Science Foundation of China (Grant No. 92263208)+3 种基金the Natural Science Foundation of Jiangsu Province (Grant No. BK20210541)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 21KJB140003)the Fundamental Research Funds for the Central Universitiesthe Open Fund of State Key Laboratory of Acoustics (Grant No. SKLA202313)。
文摘We demonstrate a method to realize unidirectional negative refraction in an acoustic parity-time(P T)-symmetric system, which is composed of a pair of metasurfaces sandwiching an air gap. The pair of metasurfaces possesses loss and gain modulations. The unidirectional negative refraction, which is strictly limited to the case of incident wave imposing on the loss end of the metasurface, is demonstrated at the exception point(EP) in this P T-symmetric system, while the incidence from the other side leads to strong reflection. Based on rigorous calculations, we explicitly show the underlying mechanism of this model to achieve unidirectional wave scatterings around the EP in the parametric space. In addition, the perfect imaging of a point source in the three-dimensional space, as a signature of negative refraction, is simulated to provide a verification of our work. We envision that this work may sharpen the understanding of P T-symmetric structures and inspire more acoustic functional devices.
基金financially supported by the Special Fund for Forest Scientific Research in the Public Welfare(201404113)the 111 Project(B13007)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13047)
文摘Microsporogenesis and flower development in Eucalyptus urophylla 9 E. grandis were examined using chromosome tableting to provide a method to predict the meiotic stages in this species. Although microsporogenesis was normal, cytokinesis during meiosis of pollen mother cells occurred simultaneously, with strong asynchronism observed in the two different lengths of stamens in a flower bud. In a single flower, the developmental period of microsporogenesis in anthers on the longer stamens was always ahead of those on the shorter stamens. Flower development was also asynchronous at different locations on a branch. Flower buds on the upper side of the branch were larger in diameter than those on the lower side. In addition,a correlation was observed between microsporogenesisdevelopment and flower bud diameter growth. The pachytene stage was first observed when the diameter of the flower buds increased to 3.0 mm, and the majority of the meiotic stages were observed when bud diameters ranged from 3.5 to5.0 mm. This study showed that the developmental stages of microsporogenesis in Eucalyptus urophylla 9 E. grandis could be distinguished readily, which may be applicable to future breeding studies.
文摘BACKGROUND The incidence and prevalence of atrial fibrillation are increasing each year,and this condition is one of the most common clinical arrhythmias.AIM To investigate the levels and significance of serum fibroblast growth factor 23(FGF-23)and miR-208 b in patients with atrial fibrillation and their relationship with prognosis.METHODS From May 2018 to October 2019,240 patients with atrial fibrillation were selected as an observation group,including 134 with paroxysmal atrial fibrillation and 106 with persistent atrial fibrillation;150 patients with healthy sinus rhythm were selected as a control group.The serum levels of FGF-23 and miR-208 b in the two groups were measured.In the observation group,cardiac parameters were determined by echocardiography.RESULTS The serum levels of FGF-23 and miR-208 b in the observation group were 210.20±89.60 ng/mL and 5.30±1.22 ng/mL,which were significantly higher than the corresponding values in the control group(P<0.05).In the observation group,the serum levels of FGF-23 and miR-208 b in patients with persistent atrial fibrillation were 234.22±70.05 ng/mL and 5.83±1.00 ng/mL,which were significantly higher than the corresponding values in patients with paroxysmal atrial fibrillation(P<0.05).The left atrial dimension(LAD)of patients with persistent atrial fibrillation was 38.81±5.11 mm,which was significantly higher than that of patients with paroxysmal atrial fibrillation(P>0.05).The serum levels of FGF-23and miR-208 b were positively correlated with the LAD(r=0.411 and 0.382,P<0.05).In the observation group,the serum levels of FGF-23 and miR-208 b in patients with a major cardiovascular event(MACE)were 243.30±72.29 ng/mL and 6.12±1.12 ng/mL,which were significantly higher than the corresponding values in patients without a MACE(P<0.05).CONCLUSION The serum levels of FGF-23 and miR-208 b are increased in patients with atrial fibrillation and are related to the type of disease,cardiac parameters,and prognosis.
基金supported by the Technology Planning Project of Huangpu District(201544-01)Medical Scientific Research Foundation of Guangdong Province(A2015287)+2 种基金Science and Technology Planning Project of Guangdong Province(2017ZC0474)Natural Science Foundation of Guangdong Province(2015A030313690)General Project of Dongguan City(Nos.201950715024922 and 2018507150241344).
文摘Previous reports have suggested that Ang-(1-7)may have a protective effect in endothelial cells against high glucose(HG)-induced cell injury thanks to a modulatory mechanism in the NF-κB signaling pathway.In this study,we have examined whether NF-κB-IL-1βand Heme oxygenase-1(HO-1)pathways contribute to the protection of Ang-(1-7)against hyperglycemia-induced inflammation and oxidative stress in human umbilical vein endothelial cells(HUVECs).Our results indicate that time-varying exposures of HUVECs,from 1 h to 24 h,to high glucose concentrations result in an increased expression of phosphorylated(p)-p65 and HO-1 in a time-dependent manner.As an inhibitor of NF-κB,pyrrolidinedithiocarbamic acid(PDTC)suppressed IL-1βproduction induced by HG.Of note,HUVECs previously treated with Ang-(1-7)(2μM)for 30 min before being exposed to HG concentrations significantly ameliorated the HG-increased in p-p65 and IL-1βexpression;whereas obviously up-regulated the level of HO-1,along with inhibition of oxidative stress,inflammation,and the HG-induced cytotoxicity.Importantly,when HUVECs were previously treated either with PDTC or IL-1Ra for 30 min before being exposed to HG,it significantly prevented damages caused by high glucose concentrations mentioned above,while the treatment of HO-1 inhibitor Sn-protoporphyrin(SnPP)before exposure to both HG and Ang-(1-7)significantly blocked the protective effect exerted by Ang-(1-7)on endothelial cells against injuries induced by HG mentioned above.To conclude,the data of this study showed that activation and inhibition of the NF-κB-IL-1βpathway and HO-1 pathway may constitute an important defense mechanism against endothelial cell damage caused by HG concentrations.We additionally gave new evidence showing that exogenous Ang-(1-7)exerts a protective effect on HUVECs against the HG-induced cell injury via the inhibition and the activation of the NF-κB-IL-1βpathway and the HO-1 pathway,respectively.
文摘Objective: To study the effects of serum Fractalkine on vascular remodeling and oxidative stress activation in patients with COPD complicated by pulmonary heart disease. Methods:Patients who were hospitalized in Chongqing Armed Corps Police Hospital due to COPD between June 2014 and April 2017 were selected, the patients with COPD alone were included in COPD group, and the patients with COPD complicated by pulmonary heart disease were included in COPD+PHD group;healthy volunteers who underwent physical examination during the same period were selected as the control group of the study. The serum was collected to determine the contents of Fractalkine, vascular remodeling indexes and oxidative stress indexes. Results: Serum Fractalkine, ANG-2, MMP2, MMP9, VEGF, FGF2, Nogo-B, ET-1 and MDA contents of COPD+PHD group and COPD group were higher than those of control group whereas T-AOC contents were lower than that of control group;serum Fractalkine, ANG-2, MMP2, MMP9, VEGF, FGF2, Nogo-B, ET-1 and MDA contents of COPD+PHD group were higher than those of COPD group whereas T-AOC content was lower than that of COPD group. Serum ANG-2, MMP2, MMP9, VEGF, FGF2, Nogo-B, ET-1 and MDA contents of COPD+PHD group of patients with high Fractalkine content were significantly higher than those of COPD+PHD group of patients with low Fractalkine content whereas T-AOC content was lower than that of COPD+PHD group of patients with low Fractalkine content. Conclusion: The increase of serum Fractalkine in patients with COPD complicated by pulmonary heart disease can aggravate the vascular remodeling and promote the oxidative stress activation.
基金supported by the Special Scientific Research Program of Shaanxi Provincial Education Department (No.21JK0716)the Natural Science Basic Research Project of Shaanxi Province (No.2022JM-217)the National Natural Science Foundation of China (No.51878537)。
文摘The wide application of CdSe quantum dots(QDs)increases its stress risk to sewage treatment systems.This study evaluated the response of nitrification performance,floc characteristics and microbial community of nitrifying sludge under long-term exposure to CdSe QDs.Results showed CdSe QDs(≥1 mg/L)would decrease the activity of ammonia monooxygenase(AMO).Under the stress of 30 mg/L CdSe QDs,the activity of AMO was reduced by 66%,while the activities of hydroxylamine oxidase and nitrite oxidoreductase were enhanced by 19.1%and 26%,respectively.Thus,the final nitrification effects were not adversely affected,and the production rates of NO_(2)^(-)-N and NO_(3)^(-)-N were accelerated.Additionally,CdSe QDs improved biomass concentration in sludge and maintained the stability of sludge settleability.High throughput sequencing analysis showed that CdSe QDs evidently reduced the abundance and diversity of microbial community in nitrifying sludge.The abundances of amino acid metabolism and lipid metabolism were enriched.Moreover,CdSe QDs decreased the fluorescence intensity of tryptophan-like protein from 2,326 to 1,179 a.u.in loosely bound extracellular polymeric substances(EPSs)and from 3,792 to 3,117 a.u.in tightly bound EPSs.To relieve CdSe QD stress,the polysaccharide content increased from0.31 to 0.61 mg/g MLSS and intracellular antioxidant defense was activated.With CdSe QD level increasing to 30 mg/L,the total antioxygenic capacity and the activities of catalase were enhanced up to 411%and 143.2%,respectively.Thereby,CdSe QDs had little adverse effects on cell membrane integrity,microbial metabolism and the abundance of Nitrospirae.
基金This work was partially supported by grants from the National Natural Science Foundation of China(No.52270029)the Tianshan Youth Project of Xinjiang Uygur Autonomous Region(No.2020Q050)the Key Research and Development Projects of Shaanxi Province(No.2018ZDCXL-SF-31-6).
文摘The global problem of petroleum contamination in soils seriously threatens environmental safety and human health.Current studies have successfully demonstrated the feasibility of bioelectrokinetic and bioelectrochemical remediation of petroleum-contaminated soils due to their easy implementation,environmental benignity,and enhanced removal efficiency compared to bioremediation.This paper reviewed recent progress and development associated with bioelectrokinetic and bioelectrochemical remediation of petroleum-contaminated soils.The working principles,removal efficiencies,affecting factors,and constraints of the two technologies were thoroughly summarized and discussed.The potentials,challenges,and future perspectives were also deliberated to shed light on how to overcome the barriers and realize widespread implementation on large scales of these two technologies.
基金supported by grants from the National Natural Science Foundation of China(Grants No.32100990 and 31800637)and the National Key Research and Development Program of China(Grant No.2019YFA0508403).
文摘Severe acute respiratory syndrome coronavirus 2(SARS-Cov-2)infection,causing CovID-19,is the most challenging pandemic of the modern era.It has resulted in over 5 million deaths worldwide.To quickly explore therapeutics for COVID-19,we utilized a previously-established system,namely CEBIT.We performed a highthroughput screening of FDA-approved drugs to inhibit the interaction between the receptor-binding domain(RBD)of SARS-CoV-2 spike protein and its obligate receptor ACE2.This interaction is essential for viral entry and therefore represents a promising therapeutic target.Based on the recruitment of interacting molecules into phase-separated condensates as a readout,we identified six positive candidates from a library of 2572 compounds,most of which have been reported to inhibit the entry of SARs-Cov-2 into host cells.Our surface plasmon resonance(SPR)and molecular docking analyses revealed the possible mechanisms via which these compounds interfere with the interaction between RBD and ACE2.Hence,our results indicate that CEBIT is highly versatile for identifying drugs against SARS-Cov-2 entry,and targeting Cov-2 entry by small molecule drugs is a viable therapeutic option to treat CovID-19 in addition to commonly used monoclonal antibodies.
