To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the dow...To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were designated.Sampling was conducted in September 2021,January,May,and July 2022.Phytoplankton species were identified from both quantitative samples and in-vivo observations.Phytoplankton was quantified by direct counting.Results show that there were 98 species belonging to 6 phyla and 78 genera.In addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the stability.The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in summer.Among 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis sp.was the dominant species in Spring,Autumn,and Winter.The niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three groups.The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in turn.The overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space.Despite this pattern,stability measurements indicated that the dominant species community remained unstable.Therefore,careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter.This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China.展开更多
A stable and highly active core‐shell heterostructure electrocatalyst is essential for catalyzing oxygen evolution reaction(OER).Here,a dual‐trimetallic core‐shell heterostructure OER electrocatalyst that consists ...A stable and highly active core‐shell heterostructure electrocatalyst is essential for catalyzing oxygen evolution reaction(OER).Here,a dual‐trimetallic core‐shell heterostructure OER electrocatalyst that consists of a NiFeWS_(2) inner core and an amorphous NiFeW(OH)_(z)outer shell is designed and synthesized using in situ electrochemical tuning.The electrochemical measurements of different as‐synthesized catalysts with a similar mass loading suggest that the core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) nanosheets exhibit the highest overall performance compared with that of other bimetallic reference catalysts for the OER.Additionally,the nanosheet arrays were in situ grown on hydrophilic‐treated carbon paper to fabricate an integrated three‐dimensional electrode that affords a current density of 10 mA cm^(−2) at a small overpotential of 182 mV and a low Tafel slope of 35 mV decade^(−1) in basic media.The Faradaic efficiency of core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) is as high as 99.5% for OER.The scanning electron microscope,transmission electron microscope,and X‐ray photoelectron spectroscopy analyses confirm that this electrode has excellent stability in morphology and elementary composition after long‐term electrochemical measurements.Importantly,density functional theory calculations further indicate that the core‐shell heterojunction increased the conductivity of the catalyst,optimized the adsorption energy of the OER intermediates,and improved the OER activity.This study provides a universal strategy for designing more active core‐shell structure electrocatalysts based on the rule of coordinated regulation between electronic transport and active sites.展开更多
Constructing self-protected metastable intermolecular composites(MICs) enables the regulation of microstructures towards boosting controllable detonation performance,and also prevents information leakage,which is mean...Constructing self-protected metastable intermolecular composites(MICs) enables the regulation of microstructures towards boosting controllable detonation performance,and also prevents information leakage,which is meaningful but challenging.Herein,a convenient and efficient method of combining highly-controlled electrophoretic assembly,surface modification and microwave heat treatment was employed to design promising heattriggered wettability switchable high-energy smart C-doped Al/Cr_(2)O_(3)MIC,and surface modification mechanism was proposed,respectively.The anti-wetting ability of the product was demonstrated by a series of tests of water contact angle,impact resistance,immersion,selfcleaning,etc.The key information recording/encryption procedures were realized by constructing a hydrophilic/hydrophobic interface and adjusting the wettability of the product.In addition,the output heat of asobtained smart MIC can reach ~1.5 kJ·g^(-1),and its attenuation rate was only ~30% even after underwater aging,further verifying its potential practicality.Thus,our design provides a promising strategy for engineering smart MIC with diversified functional structures for blasting applications and beyond.展开更多
Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configura...Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configurations,we designed a new type of binary-atom catalyst,through engineering Fe-N_(4)electronic structure with adjacent Co-N_(2)C_(2)and nitrogen-coordinated Co nanoclusters,as oxygen electrocatalysts.The resultant optimized electronic structure of the Fe-N_(4)active center favors the binding capability of intermediates and enhances oxygen reduction reaction(ORR)activity in both alkaline and acid conditions.In addition,anchoring M-N-C atomic sites on highly graphitized carbon supports guarantees of efficient charge-and mass-transports,and escorts the high bifunctional catalytic activity of the entire catalyst.Further,through the combination of electrochemical studies and in-situ X-ray absorption spectroscopy analyses,the ORR degradation mechanisms under highly oxidative conditions during oxygen evolution reaction processes were revealed.This work developed a new binary-atom catalyst and systematically investigates the effect of highly oxidative environments on ORR electrochemical behavior.It demonstrates the strategy for facilitating oxygen electrocatalytic activity and stability of the atomically dispersed M-N-C catalysts.展开更多
Introduction of the photothermal effect into transition-metal oxide photoanodes has been proven to be an effective method to improve the photoelectrochemical(PEC)water-splitting performance.However,the precise role of...Introduction of the photothermal effect into transition-metal oxide photoanodes has been proven to be an effective method to improve the photoelectrochemical(PEC)water-splitting performance.However,the precise role of the photothermal effect on the PEC performance of photoanodes is still not well understood.Herein,spinel-structured ZnFe_(2)O_(4)nanoparticles are deposited on the surface of hematite(Fe_(2)O_(3)),and the ZnFe_(2)O_(4)/Fe_(2)O_(3)photoanode achieves a high photocurrent density of 3.17 mA cm^(-2)at 1.23 V versus a reversible hydrogen electrode(VRHE)due to the photothermal effect of ZnFe_(2)O_(4).Considering that the hopping of electron small polarons induced by oxygen vacancies is thermally activated,we clarify that the main reason for the enhanced PEC performance via the photothermal effect is the promoted mobility of electron small polarons that are bound to positively charged oxygen vacancies.Under the synergistic effect of oxygen vacancies and the photothermal effect,the electron conductivity and PEC performance are significantly improved,which provide fundamental insights into the impact of the photothermal effect on the PEC performance of small polaron-type semiconductor photoanodes.展开更多
Background: Individualized corneal refractive surgery requires an understanding of the basis of higher-order aberrations before surgery. To investigate the characteristics and distribution of anterior surface wavefron...Background: Individualized corneal refractive surgery requires an understanding of the basis of higher-order aberrations before surgery. To investigate the characteristics and distribution of anterior surface wavefront aberrations in patients suitable for corneal refractive surgery. Methods: A total of 121 myopic patients (121 eyes, 18 - 45 years old) who underwent corneal refractive surgery were recruited from January to May 2016 at Affiliated Hospital, Yanbian University. Patients were randomly selected by the Pentacam anterior segment analysis system with a spherical equivalent (SE) of -0.25 to -10.00 D. The corneal anterior aberrations (total higher-order aberration;spherical aberration;Coma;Trefoil) and Q and K values were detected, and a correlation analysis of the relevant parameters was carried out. Results: The root-mean-square (RMS) of the third to sixth order aberrations of the corneal anterior wavefront aberrations at a 6 mm analysis diameter showed a decreasing trend in patients suitable for the corneal refractive surgery, and the RMS of the third order aberrations accounted for 62.92% of the total HOAs. The coma ratio (coma/total cornea higher-order aberrations) was increased with the increasing diopters, while the spherical aberration ratio (spherical aberration/total cornea higher-order aberrations) was not changed. In addition, the spherical aberration was 0.203 ± 0.082 μm (range: 0.061 to 0.503 μm), and the Q30 was -0.19 ± 0.03 (range: -0.58 to 0.31). There were significant differences in the coma aberrations of preoperative corneal anterior surface (3, 1) between the low, middle and high myopia groups (P = 0.013). The spherical equivalent was positively correlated with the corneal coma of the anterior corneal surfaces (R =?-0.241, P = 0.009), and the Q value was positively correlated with the total higher-order aberrations (R = 0.326, P Conclusions: Individual wavefront aberrations on the anterior surfaces of the cornea are comparatively different, and the Zernike coefficients are related to the degree of myopia. Spherical aberrations are the most overriding aberrations of the cornea.展开更多
A new diterpene and a new sesquiterpene were isolated from Pteris dispar and identified on the basis of spectral data including 2D NMR.Compounds 1 and 2 showed potent cytotoxic activity against KB cell.
The present study investigated a possible mechanism for endogenous endothelin-1 (ET-1) regulation of atrial natriuretic peptide (ANP) secretion in isolated perfused acute hypoxic rabbit atria. Acute hypoxia significan...The present study investigated a possible mechanism for endogenous endothelin-1 (ET-1) regulation of atrial natriuretic peptide (ANP) secretion in isolated perfused acute hypoxic rabbit atria. Acute hypoxia significantly enhanced the release of ET-1 and the expression of the ET receptor (ETR) type A and B (ETR<sub>A</sub> and ETR<sub>B</sub>) in atrial tissues, with a concomitant increase in ANP secretion. The ETR<sub>A</sub> or ETR<sub>B</sub> antagonist, BQ123 (0.3 μmol/L) or BQ788 (0.3 μmol/L), respectively attenuated hypoxia-induced ANP secretion. Both antagonists significantly attenuated the levels of hypoxiainduced atrial phosphorylated (p)-extracellular signal-regulated kinase (ERK) and p-protein kinase B (Akt). The ERK and Akt inhibitors, PD098059 (30 μmol/L) and LY294002 (30 μmol/L), respectively mimicked the effect of the ETR antagonists. These results demonstrated that acute hypoxia- mediated atrial ET-1 regulated ANP secretion through ETR and the subsequent mitogenactivated protein kinase (MAPK)/ERK and ETR-phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways. These pathways may mediate atrial endocrine functions under hypoxic conditions.展开更多
Our study investigated effects of C-type natriuretic peptide (CNP) on atrial dynamics and hypoxia inducible factor 1 alpha (HIF-1α) activity in perfused beating rat atria, under hypoxic conditions. Hypoxia significan...Our study investigated effects of C-type natriuretic peptide (CNP) on atrial dynamics and hypoxia inducible factor 1 alpha (HIF-1α) activity in perfused beating rat atria, under hypoxic conditions. Hypoxia significantly increased the levels of HIF-1α, concomitant with decreased trial dynamics. CNP (0.1 μmol/L) further decreased atrial dynamics under hypoxia and suppressed hypoxia-induced stimulation of HIF-1α expression. An adenylylcyclase (AC) activator, forskolin (0.1 μmol/L), significantly up-regulated atrial phosphodiesterase subtype 3A (PDE 3A) protein without affecting hypoxia-induced dynamics. In the presence of forskolin, the inhibitory effects of CNP on hypoxia-induced atrial dynamics and HIF-1α levels were significantly attenuated. Forskolin also prevented hypoxia-induced downregulation of PDE3A protein. These findings suggested that CNP inhibited atrial dynamics and HIF-1α activity in the isolated perfused beating rat atria under hypoxic conditions. Furthermore, both effects were modulated by the AC activator forskolin, through activation of CNP-PDE 3A signaling.展开更多
The acute onset of the vision loss by optic never injury following orbital wall reconstruction, has been reported in 0.5% - 5.0% of the cases. Visual impairment can be recovered within an early period after injury. De...The acute onset of the vision loss by optic never injury following orbital wall reconstruction, has been reported in 0.5% - 5.0% of the cases. Visual impairment can be recovered within an early period after injury. Delayed visual recovery from optic nerve injury during a procedure of orbital wall reconstruction has not been reported. We report a case of delayed recovery from optic nerve injury which occurred following orbital wall reconstruction. A 78-year-old man underwent orbital wall reconstruction for medial wall fracture and resulting enophthalmos in the right eye, one week after a traffic accident. Immediate after surgery, postoperative visual acuity in the right eye decreased to light perception, and relative afferent pupillary defect (RAPD) was detected. In spite of mega-dose steroid treatment, the visual acuity did not improve. However, 8 months after surgery, visual acuity began to recover to 0.1, and the degree of RAPD decreased. Twelve months after surgery, visual acuity in the right eye was 0.4, and pupillary light reflex was normal. Our report suggests that patients with optic neuropathy by surgery or trauma require long-term follow-up, regardless of early response to mega-dose steroid treatment.展开更多
Bismuth vanadate(BiVO_(4))is a promising photoanode material for photoelectrochemical(PEC)water oxidation.However,its performance is greatly hindered by poor bulk and interfacial charge transfer.Herein,to address this...Bismuth vanadate(BiVO_(4))is a promising photoanode material for photoelectrochemical(PEC)water oxidation.However,its performance is greatly hindered by poor bulk and interfacial charge transfer.Herein,to address this issue,iron doped vanadyl phosphate(Fe:VOPO_(4))was grafted on molybdenum doped BiVO_(4)(Mo:BiVO_(4))for significantly enhancing charge transfer and oxygen evolution kinetics simultaneously.Consequently,the resultant Fe:VOPO_(4)/Mo:BVO_(4) photoanode exhibits a remarkable photocurrent density of 6.59 mA cm^(-2) at 1.23 V versus the reversible hydrogen electrode(VRHE)under AM 1.5G illumination,over approximately 5.5 times as high as that of pristine BiVO_(4).Systematic studies have demonstrated that the hopping activation energy of small polarons is significantly reduced due to the Mo doping,resulting in accelerated bulk charge transfer.More importantly,the deposition of Fe:VOPO_(4) promotes the interfacial charge transfer between Mo:BiVO_(4) and Fe:VOPO_(4) via the construction of V-O-V and P-O bonds,in addition to facilitating water splitting kinetics.This work provides a general strategy for optimizing charge transfer process,especially at the interface between photoanodes and cocatalysts.展开更多
Atomically precise metal nanocluster and ultrasmall nanoparticle catalysts have garnered significant interest in electrocatalysis applications due to their unique geometric and electronic structures.As an intermediate...Atomically precise metal nanocluster and ultrasmall nanoparticle catalysts have garnered significant interest in electrocatalysis applications due to their unique geometric and electronic structures.As an intermediate state between single-atom catalysts(SACs)and nanoparticles in size,nanoclusters with specific low nuclearity provide designated metallic states with multiple atoms or surface sites for the adsorption and transformation of reactants/intermediates.The unique catalytic properties of nanoclusters offer a novel platform for designing effective and efficient electrocatalysts,potentially surpassing the SACs in certain catalytic reactions.This review summarizes and discusses the latest progress of nanoclusters and ultrasmall nanoparticles for various electrocatalysis applications,including oxygen reduction reaction(ORR),oxygen evolution reaction(OER),CO_(2) reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR),hydrogen evolution reaction(HER),various chemicals oxidation reaction(COR),etc.Specifically,this review highlights surface/interface chemical modification strategies and structure-properties relationships,drawing from the atomic-level insights to determine electrocatalytic performance.Lastly,we present the challenges and opportunities associated with nanocluster or ultrasmall nanoparticle electrocatalysts.展开更多
基金Supported by the National Key Scientific Research Project(No.2018YFC1508200)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX 23_0714)+1 种基金the China Scholarship Council(No.202206710066)the Construction Project of Wenzhou Hydrology High quality Development Pilot Zone(No.WZSW-GZLFZXXQ-202105)。
文摘To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were designated.Sampling was conducted in September 2021,January,May,and July 2022.Phytoplankton species were identified from both quantitative samples and in-vivo observations.Phytoplankton was quantified by direct counting.Results show that there were 98 species belonging to 6 phyla and 78 genera.In addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the stability.The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in summer.Among 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis sp.was the dominant species in Spring,Autumn,and Winter.The niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three groups.The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in turn.The overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space.Despite this pattern,stability measurements indicated that the dominant species community remained unstable.Therefore,careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter.This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China.
基金National Natural Science Foundation of China,Grant/Award Numbers:21978160,52003300,52373087Shaanxi Province Natural Science Foundation,Grant/Award Number:2024JC‐YBMS‐131。
文摘A stable and highly active core‐shell heterostructure electrocatalyst is essential for catalyzing oxygen evolution reaction(OER).Here,a dual‐trimetallic core‐shell heterostructure OER electrocatalyst that consists of a NiFeWS_(2) inner core and an amorphous NiFeW(OH)_(z)outer shell is designed and synthesized using in situ electrochemical tuning.The electrochemical measurements of different as‐synthesized catalysts with a similar mass loading suggest that the core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) nanosheets exhibit the highest overall performance compared with that of other bimetallic reference catalysts for the OER.Additionally,the nanosheet arrays were in situ grown on hydrophilic‐treated carbon paper to fabricate an integrated three‐dimensional electrode that affords a current density of 10 mA cm^(−2) at a small overpotential of 182 mV and a low Tafel slope of 35 mV decade^(−1) in basic media.The Faradaic efficiency of core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) is as high as 99.5% for OER.The scanning electron microscope,transmission electron microscope,and X‐ray photoelectron spectroscopy analyses confirm that this electrode has excellent stability in morphology and elementary composition after long‐term electrochemical measurements.Importantly,density functional theory calculations further indicate that the core‐shell heterojunction increased the conductivity of the catalyst,optimized the adsorption energy of the OER intermediates,and improved the OER activity.This study provides a universal strategy for designing more active core‐shell structure electrocatalysts based on the rule of coordinated regulation between electronic transport and active sites.
基金financially supported by the National Natural Science Foundation of China (Nos.21805014,82102635,52373087,52003300 and 22109120)Chongqing Municipal Education Commission (Nos.CXQT20026 and KJQN202201408)。
文摘Constructing self-protected metastable intermolecular composites(MICs) enables the regulation of microstructures towards boosting controllable detonation performance,and also prevents information leakage,which is meaningful but challenging.Herein,a convenient and efficient method of combining highly-controlled electrophoretic assembly,surface modification and microwave heat treatment was employed to design promising heattriggered wettability switchable high-energy smart C-doped Al/Cr_(2)O_(3)MIC,and surface modification mechanism was proposed,respectively.The anti-wetting ability of the product was demonstrated by a series of tests of water contact angle,impact resistance,immersion,selfcleaning,etc.The key information recording/encryption procedures were realized by constructing a hydrophilic/hydrophobic interface and adjusting the wettability of the product.In addition,the output heat of asobtained smart MIC can reach ~1.5 kJ·g^(-1),and its attenuation rate was only ~30% even after underwater aging,further verifying its potential practicality.Thus,our design provides a promising strategy for engineering smart MIC with diversified functional structures for blasting applications and beyond.
基金funded by the National Natural Science Foundation of China (22208331, 52003300)the Natural Sciences and Engineering Research Council of Canada (NSERC)+4 种基金the Fonds de Recherche du Québec-Nature et Technologies (FRQNT)Centre Québécois sur les Materiaux Fonctionnels (CQMF), McGill Universityécole de Technologie Supérieure (éTS)Institut National de la Recherche Scientifique (INRS)the support from the Marcelle-Gauvreau Engineering Research Chair program
文摘Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configurations,we designed a new type of binary-atom catalyst,through engineering Fe-N_(4)electronic structure with adjacent Co-N_(2)C_(2)and nitrogen-coordinated Co nanoclusters,as oxygen electrocatalysts.The resultant optimized electronic structure of the Fe-N_(4)active center favors the binding capability of intermediates and enhances oxygen reduction reaction(ORR)activity in both alkaline and acid conditions.In addition,anchoring M-N-C atomic sites on highly graphitized carbon supports guarantees of efficient charge-and mass-transports,and escorts the high bifunctional catalytic activity of the entire catalyst.Further,through the combination of electrochemical studies and in-situ X-ray absorption spectroscopy analyses,the ORR degradation mechanisms under highly oxidative conditions during oxygen evolution reaction processes were revealed.This work developed a new binary-atom catalyst and systematically investigates the effect of highly oxidative environments on ORR electrochemical behavior.It demonstrates the strategy for facilitating oxygen electrocatalytic activity and stability of the atomically dispersed M-N-C catalysts.
基金This work was supported by the National Natural Science Foundation of China(51902297,52002361,52003300,and 22109120)the Zhejiang Provincial Natural Science Foundation of China(LQ21B030002)the fund of the Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education,and Hubei Key Laboratory of Catalysis and Materials Science.
文摘Introduction of the photothermal effect into transition-metal oxide photoanodes has been proven to be an effective method to improve the photoelectrochemical(PEC)water-splitting performance.However,the precise role of the photothermal effect on the PEC performance of photoanodes is still not well understood.Herein,spinel-structured ZnFe_(2)O_(4)nanoparticles are deposited on the surface of hematite(Fe_(2)O_(3)),and the ZnFe_(2)O_(4)/Fe_(2)O_(3)photoanode achieves a high photocurrent density of 3.17 mA cm^(-2)at 1.23 V versus a reversible hydrogen electrode(VRHE)due to the photothermal effect of ZnFe_(2)O_(4).Considering that the hopping of electron small polarons induced by oxygen vacancies is thermally activated,we clarify that the main reason for the enhanced PEC performance via the photothermal effect is the promoted mobility of electron small polarons that are bound to positively charged oxygen vacancies.Under the synergistic effect of oxygen vacancies and the photothermal effect,the electron conductivity and PEC performance are significantly improved,which provide fundamental insights into the impact of the photothermal effect on the PEC performance of small polaron-type semiconductor photoanodes.
文摘Background: Individualized corneal refractive surgery requires an understanding of the basis of higher-order aberrations before surgery. To investigate the characteristics and distribution of anterior surface wavefront aberrations in patients suitable for corneal refractive surgery. Methods: A total of 121 myopic patients (121 eyes, 18 - 45 years old) who underwent corneal refractive surgery were recruited from January to May 2016 at Affiliated Hospital, Yanbian University. Patients were randomly selected by the Pentacam anterior segment analysis system with a spherical equivalent (SE) of -0.25 to -10.00 D. The corneal anterior aberrations (total higher-order aberration;spherical aberration;Coma;Trefoil) and Q and K values were detected, and a correlation analysis of the relevant parameters was carried out. Results: The root-mean-square (RMS) of the third to sixth order aberrations of the corneal anterior wavefront aberrations at a 6 mm analysis diameter showed a decreasing trend in patients suitable for the corneal refractive surgery, and the RMS of the third order aberrations accounted for 62.92% of the total HOAs. The coma ratio (coma/total cornea higher-order aberrations) was increased with the increasing diopters, while the spherical aberration ratio (spherical aberration/total cornea higher-order aberrations) was not changed. In addition, the spherical aberration was 0.203 ± 0.082 μm (range: 0.061 to 0.503 μm), and the Q30 was -0.19 ± 0.03 (range: -0.58 to 0.31). There were significant differences in the coma aberrations of preoperative corneal anterior surface (3, 1) between the low, middle and high myopia groups (P = 0.013). The spherical equivalent was positively correlated with the corneal coma of the anterior corneal surfaces (R =?-0.241, P = 0.009), and the Q value was positively correlated with the total higher-order aberrations (R = 0.326, P Conclusions: Individual wavefront aberrations on the anterior surfaces of the cornea are comparatively different, and the Zernike coefficients are related to the degree of myopia. Spherical aberrations are the most overriding aberrations of the cornea.
基金supported by the Natural Science Foundation of Guangdong Province(No.8152402301000019)Science and Technology Planning Project(No.2009B030801336)Science and Technology Planning Project of Scientific Research Institutions of Higher Learning(No.2008108101050)
文摘A new diterpene and a new sesquiterpene were isolated from Pteris dispar and identified on the basis of spectral data including 2D NMR.Compounds 1 and 2 showed potent cytotoxic activity against KB cell.
文摘The present study investigated a possible mechanism for endogenous endothelin-1 (ET-1) regulation of atrial natriuretic peptide (ANP) secretion in isolated perfused acute hypoxic rabbit atria. Acute hypoxia significantly enhanced the release of ET-1 and the expression of the ET receptor (ETR) type A and B (ETR<sub>A</sub> and ETR<sub>B</sub>) in atrial tissues, with a concomitant increase in ANP secretion. The ETR<sub>A</sub> or ETR<sub>B</sub> antagonist, BQ123 (0.3 μmol/L) or BQ788 (0.3 μmol/L), respectively attenuated hypoxia-induced ANP secretion. Both antagonists significantly attenuated the levels of hypoxiainduced atrial phosphorylated (p)-extracellular signal-regulated kinase (ERK) and p-protein kinase B (Akt). The ERK and Akt inhibitors, PD098059 (30 μmol/L) and LY294002 (30 μmol/L), respectively mimicked the effect of the ETR antagonists. These results demonstrated that acute hypoxia- mediated atrial ET-1 regulated ANP secretion through ETR and the subsequent mitogenactivated protein kinase (MAPK)/ERK and ETR-phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways. These pathways may mediate atrial endocrine functions under hypoxic conditions.
文摘Our study investigated effects of C-type natriuretic peptide (CNP) on atrial dynamics and hypoxia inducible factor 1 alpha (HIF-1α) activity in perfused beating rat atria, under hypoxic conditions. Hypoxia significantly increased the levels of HIF-1α, concomitant with decreased trial dynamics. CNP (0.1 μmol/L) further decreased atrial dynamics under hypoxia and suppressed hypoxia-induced stimulation of HIF-1α expression. An adenylylcyclase (AC) activator, forskolin (0.1 μmol/L), significantly up-regulated atrial phosphodiesterase subtype 3A (PDE 3A) protein without affecting hypoxia-induced dynamics. In the presence of forskolin, the inhibitory effects of CNP on hypoxia-induced atrial dynamics and HIF-1α levels were significantly attenuated. Forskolin also prevented hypoxia-induced downregulation of PDE3A protein. These findings suggested that CNP inhibited atrial dynamics and HIF-1α activity in the isolated perfused beating rat atria under hypoxic conditions. Furthermore, both effects were modulated by the AC activator forskolin, through activation of CNP-PDE 3A signaling.
文摘The acute onset of the vision loss by optic never injury following orbital wall reconstruction, has been reported in 0.5% - 5.0% of the cases. Visual impairment can be recovered within an early period after injury. Delayed visual recovery from optic nerve injury during a procedure of orbital wall reconstruction has not been reported. We report a case of delayed recovery from optic nerve injury which occurred following orbital wall reconstruction. A 78-year-old man underwent orbital wall reconstruction for medial wall fracture and resulting enophthalmos in the right eye, one week after a traffic accident. Immediate after surgery, postoperative visual acuity in the right eye decreased to light perception, and relative afferent pupillary defect (RAPD) was detected. In spite of mega-dose steroid treatment, the visual acuity did not improve. However, 8 months after surgery, visual acuity began to recover to 0.1, and the degree of RAPD decreased. Twelve months after surgery, visual acuity in the right eye was 0.4, and pupillary light reflex was normal. Our report suggests that patients with optic neuropathy by surgery or trauma require long-term follow-up, regardless of early response to mega-dose steroid treatment.
基金supported by the National Natural Science Foundation of China(52373087,51973235,52173091,22208331 and 62274050)Program for Leading Talents of National Ethnic Affairs Commission of China(MZR21001)+2 种基金Hubei Provincial Natural Science Foundation of China(2021CFA022)Wuhan Science and Technology Bureau(2020010601012198)Zhejiang Provincial Natural Science Foundation of China under Grant No.LZ21E020002.
文摘Bismuth vanadate(BiVO_(4))is a promising photoanode material for photoelectrochemical(PEC)water oxidation.However,its performance is greatly hindered by poor bulk and interfacial charge transfer.Herein,to address this issue,iron doped vanadyl phosphate(Fe:VOPO_(4))was grafted on molybdenum doped BiVO_(4)(Mo:BiVO_(4))for significantly enhancing charge transfer and oxygen evolution kinetics simultaneously.Consequently,the resultant Fe:VOPO_(4)/Mo:BVO_(4) photoanode exhibits a remarkable photocurrent density of 6.59 mA cm^(-2) at 1.23 V versus the reversible hydrogen electrode(VRHE)under AM 1.5G illumination,over approximately 5.5 times as high as that of pristine BiVO_(4).Systematic studies have demonstrated that the hopping activation energy of small polarons is significantly reduced due to the Mo doping,resulting in accelerated bulk charge transfer.More importantly,the deposition of Fe:VOPO_(4) promotes the interfacial charge transfer between Mo:BiVO_(4) and Fe:VOPO_(4) via the construction of V-O-V and P-O bonds,in addition to facilitating water splitting kinetics.This work provides a general strategy for optimizing charge transfer process,especially at the interface between photoanodes and cocatalysts.
基金financially supported by the National Natural Science Foundation of China(22208331)the Natural Sciences and Engineering Research Council of Canada(NSERC)+2 种基金the Fonds de Recherche du Québec-Nature et Technologies(FRQNT)McGill University,Institut National de la Recherche Scientifique(INRS)andÉcole de Technologie Supérieure(ÉTS).
文摘Atomically precise metal nanocluster and ultrasmall nanoparticle catalysts have garnered significant interest in electrocatalysis applications due to their unique geometric and electronic structures.As an intermediate state between single-atom catalysts(SACs)and nanoparticles in size,nanoclusters with specific low nuclearity provide designated metallic states with multiple atoms or surface sites for the adsorption and transformation of reactants/intermediates.The unique catalytic properties of nanoclusters offer a novel platform for designing effective and efficient electrocatalysts,potentially surpassing the SACs in certain catalytic reactions.This review summarizes and discusses the latest progress of nanoclusters and ultrasmall nanoparticles for various electrocatalysis applications,including oxygen reduction reaction(ORR),oxygen evolution reaction(OER),CO_(2) reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR),hydrogen evolution reaction(HER),various chemicals oxidation reaction(COR),etc.Specifically,this review highlights surface/interface chemical modification strategies and structure-properties relationships,drawing from the atomic-level insights to determine electrocatalytic performance.Lastly,we present the challenges and opportunities associated with nanocluster or ultrasmall nanoparticle electrocatalysts.
