The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan h...The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan highsulfidation Cu-Au deposit,the Luoboling porphyry Cu-Mo deposit,the transitional style Cu deposit(Longjiangting and Wuziqilong)and the Yueyang low-sulfidation Agpolymetallic deposit(Zhang,2013;Zhang et al.,2003)展开更多
0 INTRODUCTION The Andean orogenic belt,a globally significant active continental margin(Lamb et al.,1997),extends in a north-south direction along the western coast of South America.The Colombian Andes,located in the...0 INTRODUCTION The Andean orogenic belt,a globally significant active continental margin(Lamb et al.,1997),extends in a north-south direction along the western coast of South America.The Colombian Andes,located in the northern segment of this orogen,constitute a vital component and host abundant Au-Cu resources.Three principal Au-Cu metallogenic belts(Chocó,Middle Cauca,and Antioquia)are developed from west to east across Colombia(Lesage et al.,2013;Sillitoe,2008;Figure 1a).展开更多
Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a...Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.展开更多
Constructing heterojunction photocatalysts is a highly effective strategy for achieving overall water splitting,particularly by overcoming the challenge of sluggish electron-hole transport.This study employed a defect...Constructing heterojunction photocatalysts is a highly effective strategy for achieving overall water splitting,particularly by overcoming the challenge of sluggish electron-hole transport.This study employed a defect-induced in situ growth approach to anchor NiSe onto carbon-vacancy-rich C_(3)N_(5)(C_(v)-C_(3)N_(5)),forming interfacial Ni-N bonds.The resulting NiSe/C_(v)-C_(3)N_(5)heterojunction exhibited stoichiometric H_(2)and O_(2)evolution rates of 1956.1 and 989.1μmol g^(-1)h^(-1),respectively,8.4 times higher than a counterpart lacking interfacial bonding.Both theoretical calculations and experimental data confirmed that the Ni–N bonds were instrumental in enhancing photocatalytic performance by inducing and reinforcing S-scheme charge transfer.Illumination X-ray photoelectron spectroscopy analysis revealed that a synergistic charge transfer pathway:photoexcited electrons from the NiSe conduction band migrated sequentially to Ni atoms,then to N atoms,and ultimately recombined with holes in the C_(v)-C_(3)N_(5)valence band.Moreover,these interfacial bonds significantly lowered the energy barrier and shortened the transport distance for electron transfer,amplifying the built-in interfacial electric field and accelerating charge dynamics.This study provides critical insights into the rational design of heterojunction photocatalysts for efficient water splitting.展开更多
Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic env...Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic environmental degradation behavior.In this study,photodegradation of a representative of BT-UVs,2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P),was investigated under simulated sunlight irradiation.Results show that UV-P photodegrades slower under neutral conditions (neutral form) than under acidic or alkaline conditions (cationic and anionic forms).Indirect photodegradation is a dominant elimination pathway of UV-P in coastal seawaters.Dissolved organic matter (DOM) from seawaters accelerate the photodegradation rates mainly through excited triplet DOM (3DOM*),and the roles of singlet oxygen and hydroxyl radical are negligible in the matrixes.DOM from seawaters impacted by mariculture exhibits higher steady-state concentration of 3DOM*([3DOM*]) relative to those from pristine seawaters,leading to higher photosensitizing effects on the photodegradation.Halide ions inhibit the DOM-sensitized photodegradation of UV-P by decreasing [3DOM*].Photodegradation half-lives of UV-P are estimated to range from 24.38 to 49.66 hr in field water bodies of the Yellow River estuary.These results are of importance for assessing environmental fate and risk UV-P in coastal water bodies.展开更多
During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella caus...During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella cause a male infertility syndrome,multiple morphological abnormalities of the flagella(MMAF),while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential.However,evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited.Here,we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38(Ccdc38)via inducing a nonsense mutation and find that the males are infertile.The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes.We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm.Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3,a protein associated with acrosome biogenesis,in testes and an aberrant distribution of TEKT3 in sperm.We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility.Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.展开更多
Alternative brominated flame retardants（BFRs） have become prevalent as a consequence of restrictions on the use of polybrominated diphenyl ethers（PBDEs）. For risk assessment of these alternatives, knowledge of the...Alternative brominated flame retardants（BFRs） have become prevalent as a consequence of restrictions on the use of polybrominated diphenyl ethers（PBDEs）. For risk assessment of these alternatives, knowledge of their metabolism via cytochrome P450 enzymes is needed.We have previously proved that density functional theory（DFT） is able to predict the metabolism of PBDEs by revealing the molecular mechanisms. In the current study, the reactivity of 1,2-bis（2,4,6-tribromophenoxy）ethane and structurally similar chemicals with the Compound I model representing the active site of P450 enzymes was investigated. The DFT calculations delineated reaction pathways which lead to reasonable explanations for products that were detected by wet experiments, meanwhile intermediates which cannot be determined were also proposed. Results showed that alkyl hydrogen abstraction will lead to bis（2,4,6-tribromophenoxy）ethanol, which may undergo hydrolysis yielding2,4,6-tribromophenol, a neurotoxic compound. In addition, a general pattern of oxidation reactivity regarding the 2,4,6-tribromophenyl moiety was observed among several model compounds. Our study has provided insights for convenient evaluation of the metabolism of other structurally similar BFRs.展开更多
The parabrachial nucleus(PBN)integrates interoceptive and exteroceptive information to control various behavioral and physiological processes including breathing,emotion,and sleep/wake regulation through the neural ci...The parabrachial nucleus(PBN)integrates interoceptive and exteroceptive information to control various behavioral and physiological processes including breathing,emotion,and sleep/wake regulation through the neural circuits that connect to the forebrain and the brainstem.However,the precise identity and function of distinct PBN subpopulations are still largely unknown.Here,we leveraged molecular characterization,retrograde tracing,optogenetics,chemogenetics,and electrocortical recording approaches to identify a small subpopulation of neurotensin-expressing neurons in the PBN that largely project to the emotional control regions in the forebrain,rather than the medulla.Their activation induces freezing and anxiety-like behaviors,which in turn result in tachypnea.In addition,optogenetic and chemogenetic manipulations of these neurons revealed their function in promoting wakefulness and maintaining sleep architecture.We propose that these neurons comprise a PBN subpopulation with specific gene expression,connectivity,and function,which play essential roles in behavioral and physiological regulation.展开更多
Environmental acidification impairs microorganism diversity and their functions on substance transformation.Rhodococcus is a ubiquitously distributed genus for contaminant detoxification in the environment,and it can ...Environmental acidification impairs microorganism diversity and their functions on substance transformation.Rhodococcus is a ubiquitously distributed genus for contaminant detoxification in the environment,and it can also adapt a certain range of pH.This work interpreted the acid responses from both phenotype and metabolism in strain Rhodococcus biphenylivorans TG9^(T)(TG9)induced at pH 3.The phenotype alterations were described with the number of culturable and viable cells,intracellular ATP concentrations,cell shape and entocyte,degradation efficiency of polychlorinated biphenyl(PCB)31 and biphenyl.The number of culturable cells maintained rather stable within the first 10 days,even though the other phenotypes had noticeable alterations,indicating that TG9 possesses certain capacities to survive under acid stress.The metabolism responses were interpreted based on transcription analyses with four treatments including log phase(LP),acid-induced(PER),early recovery after removing acid(RE)and later recovery(REL).With the overview on the expression regulations among the 4 treatments,the RE sample presented more upregulated and less downregulated genes,suggesting that its metabolism was somehow more active after recovering from acid stress.In addition,the response mechanism was interpreted on 10 individual metabolism pathways mainly covering protein modification,antioxidation,antipermeability,H+consumption,neutralization and extrusion.Furthermore,the transcription variations were verified with RT-qPCR on 8 genes with 24-hr,48-hr and 72-hr acid treatment.Taken together,TG9 possesses comprehensive metabolism strategies defending against acid stress.Consequently,a model was built to provide an integrate insight to understand the acid resistance/tolerance metabolisms in microorganisms.展开更多
Amines have been considered as promising candidates for post-combustion CO2 capture. A mechanistic understanding for the chemical processes involved in the capture and release of CO2 is important for the rational desi...Amines have been considered as promising candidates for post-combustion CO2 capture. A mechanistic understanding for the chemical processes involved in the capture and release of CO2 is important for the rational design of amines. In this study, the structural effects of amines on the kinetic competition among three typical products（carbamates, carbamic acids and bicarbonate） from amines ＋ CO2 were investigated, in contrast to previous thermodynamic studies to tune the reaction of amines with CO2 based on desirable reaction enthalpy and reaction stoichiometry. We used a quantum chemical method to calculate the activation energies（Ea） for the reactions of a range of substituted monoethanolamines with CO2 covering three pathways to the three products. The results indicate that the formation of carbamates is the most favorable, among the three considered products. In addition, we found that the Eavalues for all pathways linearly correlate with pK aof amines, and more importantly, the kinetic competition between carbamate and bicarbonate absorption pathways varies with p Kaof the amines, i.e. stronger basicity results in less difference in Ea. These results highlight the importance of the consideration of kinetic competition among different reaction pathways in amine design.展开更多
As primary degradation products of phthalate esters,phthalate monoesters(MPEs)have been widely detected in various aquatic environments and drawn growing toxicological concerns.Hydrolysis kinetics that is of importanc...As primary degradation products of phthalate esters,phthalate monoesters(MPEs)have been widely detected in various aquatic environments and drawn growing toxicological concerns.Hydrolysis kinetics that is of importance for assessing environmental persistence of chemicals remain elusive for MPEs.Herein,kinetics of base-catalyzed and neutral hydrolysis for 18 MPEs with different leaving groups was investigated by density functional theory calculation.Results indicate that MPEs with leaving groups having p Kaof<10 prefer dissociative transition states.MPEs are more persistent than their parents,and their hydrolysis half-lives were calculated to vary from 3.4 min to 79.2 years(p H=7–9).A quantitative structure-activity relationship model was developed for predicting the hydrolysis kinetics parameters.It was found that p Kaof the leaving groups and electronegativity of the MPEs are key factors determining the hydrolysis kinetics.This work may lay a theoretical foundation for better understanding the chemical process that governs MPE persistence in aquatic environments.展开更多
Distributed collaborative control strategies for microgrids often use periodic time to trigger communication,which is likely to enhance the burden of communication and increase the frequency of controller updates,lead...Distributed collaborative control strategies for microgrids often use periodic time to trigger communication,which is likely to enhance the burden of communication and increase the frequency of controller updates,leading to greater waste of communication resources.In response to this problem,a distributed cooperative control strategy triggered by an adaptive event is proposed.By introducing an adaptive event triggering mechanism in the distributed controller,the triggering parameters are dynamically adjusted so that the distributed controller can communicate only at a certain time,the communication pressure is reduced,and the DC bus voltage deviation is effectively reduced,at the same time,the accuracy of power distribution is improved.The MATLAB/Simulink modeling and simulation results prove the correctness and effectiveness of the proposed control strategy.展开更多
[Objectives] The purpose of this study is to dissociate endophytic fungus producing diterpenoids from Torreya fargesii tissue and examines its inhibiting effect on tumor cells. [Methods]Plant endophytes were isolated ...[Objectives] The purpose of this study is to dissociate endophytic fungus producing diterpenoids from Torreya fargesii tissue and examines its inhibiting effect on tumor cells. [Methods]Plant endophytes were isolated and purified to study their resistance to Gram-positive( G+) and Gram-negative bacteria( G-). High performance liquid chromatography( HPLC) was used for analysis of the retention time,relative peak area and percentage content of its metabolite. By liquid chromatography-mass spectrometry( HPLC-MS),the material characteristic of the ion pair information of the metabolites was measured. The bacterial strain was also classified. [Results] The results showed that the secondary metabolites produced by the strain BP6 T3 possessed double resistance to G+and G-bacteria. The strain was identified as Penicillium sp by preliminary classification. Through HPLC analysis,the retention time of fermentation extracts was 12. 8 min with almost the same as the standard of taxol. According to the chromatograph,the relative peak area was 12 887. 11,the average relative percentage was about 15. 8%,and the content of taxol analogs in fermentation broth reached 16. 59 mg/L. The material characteristic of the formation of ion fragments of taxane analogues in metabolic extracts was identical to that of the taxol standard determined by HPLC-MS. It can be initially determined that strain BP6 T3 can produce taxane compounds. Taxol substance produced by this strain had obvious inhibitory effect on Hela cells with the concentration increasing. Different precursors had a significant effect on the production of paclitaxel metabolites in this strain. L-phenylalanine was used as the precursor and the yield increased most,with an increase rate of 425. 7%. [Conclusions] The strain is expected to be used for mass production in antitumor drug taxol.展开更多
Various computational methods were employed to investigate the zwitterion formation,a critical step for the reaction of monoethanolamine with CO2,in five solvents(water,monoethanolamine,propylamine,methanol and chloro...Various computational methods were employed to investigate the zwitterion formation,a critical step for the reaction of monoethanolamine with CO2,in five solvents(water,monoethanolamine,propylamine,methanol and chloroform)to probe the effect of hydrogen bond capacity of solvents on the reaction of amine with CO2 occurring in the amine-based CO2 capture process.The results indicate that the zwitterion can be formed in all considered solvents except chloroform.For two pairs of solvents(methanol and monoethanolamine,propylamine and chloroform)with similar dielectric constant but different hydrogen bond capacity,the solvents with higher hydrogen bond capacity(monoethanolamine and propylamine)facilitate the zwitterion formation.More importantly,kinetics parameters such as activation free energy for the zwitterion formation are more relevant to the hydrogen bond capacity than to dielectric constant of the considered solvents,clarifying the hydrogen bond capacity could be more important than dielectric constant in determining the kinetics of monoethanolamine with CO2.展开更多
Predicting the logarithm of hexadecane/air partition coefficient(L)for organic compounds is crucial for understanding the environmental behavior and fate of organic compounds and developing prediction models with poly...Predicting the logarithm of hexadecane/air partition coefficient(L)for organic compounds is crucial for understanding the environmental behavior and fate of organic compounds and developing prediction models with polyparameter linear free energy relationships.Herein,two quantitative structure activity relationship(QSAR)models were developed with 1272 L values for the organic compounds by using multiple linear regression(MLR)and support vector machine(SVM)algorithms.On the basis of the OECD principles,the goodness of fit,robustness and predictive ability for the developed models were evaluated.The SVM model was first developed,and the predictive capability for the SVM model is slightly better than that for the MLR model.The applicability domain(AD)of these two models has been extended to include more kinds of emerging pollutants,i.e.,oraganosilicon compounds.The developed QSAR models can be used for predicting L values of various organic compounds.The van derWaals interactions between the organic compound and the hexadecane have a significant effect on the L value of the compound.These in silico models developed in current study can provide an alternative to experimental method for high-throughput obtaining L values of organic compounds.展开更多
基金financially supported by Zijin Mining Group(No.01612216)the Ministry of Natural Resources,China(No.ZKKJ202426)。
文摘The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan highsulfidation Cu-Au deposit,the Luoboling porphyry Cu-Mo deposit,the transitional style Cu deposit(Longjiangting and Wuziqilong)and the Yueyang low-sulfidation Agpolymetallic deposit(Zhang,2013;Zhang et al.,2003)
基金supported by the National Natural Science Foundation of China(No.42572076)the Continental Gold Ltd.,Colombian Branch(No.CG-EXP-041-23).
文摘0 INTRODUCTION The Andean orogenic belt,a globally significant active continental margin(Lamb et al.,1997),extends in a north-south direction along the western coast of South America.The Colombian Andes,located in the northern segment of this orogen,constitute a vital component and host abundant Au-Cu resources.Three principal Au-Cu metallogenic belts(Chocó,Middle Cauca,and Antioquia)are developed from west to east across Colombia(Lesage et al.,2013;Sillitoe,2008;Figure 1a).
基金supported by grants from the Key R and D Program of Zhejiang(Grant Nos.2022C02032 and 2022C02030)the SanNong JiuFang Science and Technology Cooperation Project of Zhejiang Province(Grant No.2023SNJF008)+1 种基金the Grand Science and Technology Special Project of Zhejiang Province(Grant No.2021C02065)the Science and Technology Plan Project of Jiaxing(Grant No.2023AZ11002).
文摘Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.
文摘Constructing heterojunction photocatalysts is a highly effective strategy for achieving overall water splitting,particularly by overcoming the challenge of sluggish electron-hole transport.This study employed a defect-induced in situ growth approach to anchor NiSe onto carbon-vacancy-rich C_(3)N_(5)(C_(v)-C_(3)N_(5)),forming interfacial Ni-N bonds.The resulting NiSe/C_(v)-C_(3)N_(5)heterojunction exhibited stoichiometric H_(2)and O_(2)evolution rates of 1956.1 and 989.1μmol g^(-1)h^(-1),respectively,8.4 times higher than a counterpart lacking interfacial bonding.Both theoretical calculations and experimental data confirmed that the Ni–N bonds were instrumental in enhancing photocatalytic performance by inducing and reinforcing S-scheme charge transfer.Illumination X-ray photoelectron spectroscopy analysis revealed that a synergistic charge transfer pathway:photoexcited electrons from the NiSe conduction band migrated sequentially to Ni atoms,then to N atoms,and ultimately recombined with holes in the C_(v)-C_(3)N_(5)valence band.Moreover,these interfacial bonds significantly lowered the energy barrier and shortened the transport distance for electron transfer,amplifying the built-in interfacial electric field and accelerating charge dynamics.This study provides critical insights into the rational design of heterojunction photocatalysts for efficient water splitting.
基金supported by the National Key R&D Program of China(No.2018YFC1801604)the National Natural Science Foundation of China(No.21661142001)
文摘Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic environmental degradation behavior.In this study,photodegradation of a representative of BT-UVs,2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P),was investigated under simulated sunlight irradiation.Results show that UV-P photodegrades slower under neutral conditions (neutral form) than under acidic or alkaline conditions (cationic and anionic forms).Indirect photodegradation is a dominant elimination pathway of UV-P in coastal seawaters.Dissolved organic matter (DOM) from seawaters accelerate the photodegradation rates mainly through excited triplet DOM (3DOM*),and the roles of singlet oxygen and hydroxyl radical are negligible in the matrixes.DOM from seawaters impacted by mariculture exhibits higher steady-state concentration of 3DOM*([3DOM*]) relative to those from pristine seawaters,leading to higher photosensitizing effects on the photodegradation.Halide ions inhibit the DOM-sensitized photodegradation of UV-P by decreasing [3DOM*].Photodegradation half-lives of UV-P are estimated to range from 24.38 to 49.66 hr in field water bodies of the Yellow River estuary.These results are of importance for assessing environmental fate and risk UV-P in coastal water bodies.
基金supported by the National Key Research and Development Program of China(2021YFC2701400)in part by the National Natural Science Foundation of China(32000393 and 32288101).
文摘During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella cause a male infertility syndrome,multiple morphological abnormalities of the flagella(MMAF),while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential.However,evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited.Here,we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38(Ccdc38)via inducing a nonsense mutation and find that the males are infertile.The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes.We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm.Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3,a protein associated with acrosome biogenesis,in testes and an aberrant distribution of TEKT3 in sperm.We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility.Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.
基金supported by the National Basic Research Program(No.2013CB430403)the National Natural Science Foundation(Nos.21137001,21325729,and 21173211)of Chinasupported by Supercomputing Center of Dalian University of Technology
文摘Alternative brominated flame retardants（BFRs） have become prevalent as a consequence of restrictions on the use of polybrominated diphenyl ethers（PBDEs）. For risk assessment of these alternatives, knowledge of their metabolism via cytochrome P450 enzymes is needed.We have previously proved that density functional theory（DFT） is able to predict the metabolism of PBDEs by revealing the molecular mechanisms. In the current study, the reactivity of 1,2-bis（2,4,6-tribromophenoxy）ethane and structurally similar chemicals with the Compound I model representing the active site of P450 enzymes was investigated. The DFT calculations delineated reaction pathways which lead to reasonable explanations for products that were detected by wet experiments, meanwhile intermediates which cannot be determined were also proposed. Results showed that alkyl hydrogen abstraction will lead to bis（2,4,6-tribromophenoxy）ethanol, which may undergo hydrolysis yielding2,4,6-tribromophenol, a neurotoxic compound. In addition, a general pattern of oxidation reactivity regarding the 2,4,6-tribromophenyl moiety was observed among several model compounds. Our study has provided insights for convenient evaluation of the metabolism of other structurally similar BFRs.
基金supported by the University of Michigan startup funds and the NIH Grants R01 AT011652 and R01 HL156989.
文摘The parabrachial nucleus(PBN)integrates interoceptive and exteroceptive information to control various behavioral and physiological processes including breathing,emotion,and sleep/wake regulation through the neural circuits that connect to the forebrain and the brainstem.However,the precise identity and function of distinct PBN subpopulations are still largely unknown.Here,we leveraged molecular characterization,retrograde tracing,optogenetics,chemogenetics,and electrocortical recording approaches to identify a small subpopulation of neurotensin-expressing neurons in the PBN that largely project to the emotional control regions in the forebrain,rather than the medulla.Their activation induces freezing and anxiety-like behaviors,which in turn result in tachypnea.In addition,optogenetic and chemogenetic manipulations of these neurons revealed their function in promoting wakefulness and maintaining sleep architecture.We propose that these neurons comprise a PBN subpopulation with specific gene expression,connectivity,and function,which play essential roles in behavioral and physiological regulation.
基金supported by the National Key Research and Development Program of China(No.2019YFC1803700)the National Natural Science Foundation of China(Nos.21876149 and 42077125).
文摘Environmental acidification impairs microorganism diversity and their functions on substance transformation.Rhodococcus is a ubiquitously distributed genus for contaminant detoxification in the environment,and it can also adapt a certain range of pH.This work interpreted the acid responses from both phenotype and metabolism in strain Rhodococcus biphenylivorans TG9^(T)(TG9)induced at pH 3.The phenotype alterations were described with the number of culturable and viable cells,intracellular ATP concentrations,cell shape and entocyte,degradation efficiency of polychlorinated biphenyl(PCB)31 and biphenyl.The number of culturable cells maintained rather stable within the first 10 days,even though the other phenotypes had noticeable alterations,indicating that TG9 possesses certain capacities to survive under acid stress.The metabolism responses were interpreted based on transcription analyses with four treatments including log phase(LP),acid-induced(PER),early recovery after removing acid(RE)and later recovery(REL).With the overview on the expression regulations among the 4 treatments,the RE sample presented more upregulated and less downregulated genes,suggesting that its metabolism was somehow more active after recovering from acid stress.In addition,the response mechanism was interpreted on 10 individual metabolism pathways mainly covering protein modification,antioxidation,antipermeability,H+consumption,neutralization and extrusion.Furthermore,the transcription variations were verified with RT-qPCR on 8 genes with 24-hr,48-hr and 72-hr acid treatment.Taken together,TG9 possesses comprehensive metabolism strategies defending against acid stress.Consequently,a model was built to provide an integrate insight to understand the acid resistance/tolerance metabolisms in microorganisms.
基金supported by the National Natural Science Foundation of China (Nos. 21207016, 21325729)the Fundamental Research Funds for the Central Universities (No. DUT12RC(3)07)+1 种基金the Liaoning Provincial Education Department (No. L2012021)Program for Changjiang Scholars and Innovative Research Team in University (No. IRT_13R05)
文摘Amines have been considered as promising candidates for post-combustion CO2 capture. A mechanistic understanding for the chemical processes involved in the capture and release of CO2 is important for the rational design of amines. In this study, the structural effects of amines on the kinetic competition among three typical products（carbamates, carbamic acids and bicarbonate） from amines ＋ CO2 were investigated, in contrast to previous thermodynamic studies to tune the reaction of amines with CO2 based on desirable reaction enthalpy and reaction stoichiometry. We used a quantum chemical method to calculate the activation energies（Ea） for the reactions of a range of substituted monoethanolamines with CO2 covering three pathways to the three products. The results indicate that the formation of carbamates is the most favorable, among the three considered products. In addition, we found that the Eavalues for all pathways linearly correlate with pK aof amines, and more importantly, the kinetic competition between carbamate and bicarbonate absorption pathways varies with p Kaof the amines, i.e. stronger basicity results in less difference in Ea. These results highlight the importance of the consideration of kinetic competition among different reaction pathways in amine design.
基金supported by the National Natural Science Foundation of China (No.22136001)the National Key R&D Program of China (No.2022YFC3902100)+2 种基金the Key R&D Program of Hebei Province (No.21374001D)the Supercomputing Center of Dalian University of Technologythe National Supercomputer Center in Tianjin。
文摘As primary degradation products of phthalate esters,phthalate monoesters(MPEs)have been widely detected in various aquatic environments and drawn growing toxicological concerns.Hydrolysis kinetics that is of importance for assessing environmental persistence of chemicals remain elusive for MPEs.Herein,kinetics of base-catalyzed and neutral hydrolysis for 18 MPEs with different leaving groups was investigated by density functional theory calculation.Results indicate that MPEs with leaving groups having p Kaof<10 prefer dissociative transition states.MPEs are more persistent than their parents,and their hydrolysis half-lives were calculated to vary from 3.4 min to 79.2 years(p H=7–9).A quantitative structure-activity relationship model was developed for predicting the hydrolysis kinetics parameters.It was found that p Kaof the leaving groups and electronegativity of the MPEs are key factors determining the hydrolysis kinetics.This work may lay a theoretical foundation for better understanding the chemical process that governs MPE persistence in aquatic environments.
基金funded by the Natural Science Foundation of Shaanxi Province,Grant No.2021GY-135the Scientific Research Project of Yan’an University,Grant No.YDQ2018-07.
文摘Distributed collaborative control strategies for microgrids often use periodic time to trigger communication,which is likely to enhance the burden of communication and increase the frequency of controller updates,leading to greater waste of communication resources.In response to this problem,a distributed cooperative control strategy triggered by an adaptive event is proposed.By introducing an adaptive event triggering mechanism in the distributed controller,the triggering parameters are dynamically adjusted so that the distributed controller can communicate only at a certain time,the communication pressure is reduced,and the DC bus voltage deviation is effectively reduced,at the same time,the accuracy of power distribution is improved.The MATLAB/Simulink modeling and simulation results prove the correctness and effectiveness of the proposed control strategy.
基金Supported by Provincial College Students’Innovation and Entrepreneurship Training Program of Colleges and Universities in Hubei Province in 2017(2013)"Strategic Emerging(Pillar)Industrial Talent Training Program"of Colleges and Universities in Hubei Province[Hubei Provincial Department of Education EJiao Gao(201711798030)No.11]+2 种基金Pilot Funded Project of"Comprehensive Professional Reform"of Provincial Department of Education and Provincial Department of Finance[EJiao Gao Ban(2014)No.6]Hubei Educational Science"Twelfth Five-Year Plan"Project(2014B272)School Youth Natural Science Foundation(2013dhzk003)
文摘[Objectives] The purpose of this study is to dissociate endophytic fungus producing diterpenoids from Torreya fargesii tissue and examines its inhibiting effect on tumor cells. [Methods]Plant endophytes were isolated and purified to study their resistance to Gram-positive( G+) and Gram-negative bacteria( G-). High performance liquid chromatography( HPLC) was used for analysis of the retention time,relative peak area and percentage content of its metabolite. By liquid chromatography-mass spectrometry( HPLC-MS),the material characteristic of the ion pair information of the metabolites was measured. The bacterial strain was also classified. [Results] The results showed that the secondary metabolites produced by the strain BP6 T3 possessed double resistance to G+and G-bacteria. The strain was identified as Penicillium sp by preliminary classification. Through HPLC analysis,the retention time of fermentation extracts was 12. 8 min with almost the same as the standard of taxol. According to the chromatograph,the relative peak area was 12 887. 11,the average relative percentage was about 15. 8%,and the content of taxol analogs in fermentation broth reached 16. 59 mg/L. The material characteristic of the formation of ion fragments of taxane analogues in metabolic extracts was identical to that of the taxol standard determined by HPLC-MS. It can be initially determined that strain BP6 T3 can produce taxane compounds. Taxol substance produced by this strain had obvious inhibitory effect on Hela cells with the concentration increasing. Different precursors had a significant effect on the production of paclitaxel metabolites in this strain. L-phenylalanine was used as the precursor and the yield increased most,with an increase rate of 425. 7%. [Conclusions] The strain is expected to be used for mass production in antitumor drug taxol.
基金supported by the National Natural Science Foundation of China(Nos.21876024 and 21677028)the Major International(Regional)Joint Research Project(No.21661142001)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT_13R05)the Programme of Introducing Talents of Discipline to Universities(No.B13012)Supercomputing Center of Dalian University of Technology
文摘Various computational methods were employed to investigate the zwitterion formation,a critical step for the reaction of monoethanolamine with CO2,in five solvents(water,monoethanolamine,propylamine,methanol and chloroform)to probe the effect of hydrogen bond capacity of solvents on the reaction of amine with CO2 occurring in the amine-based CO2 capture process.The results indicate that the zwitterion can be formed in all considered solvents except chloroform.For two pairs of solvents(methanol and monoethanolamine,propylamine and chloroform)with similar dielectric constant but different hydrogen bond capacity,the solvents with higher hydrogen bond capacity(monoethanolamine and propylamine)facilitate the zwitterion formation.More importantly,kinetics parameters such as activation free energy for the zwitterion formation are more relevant to the hydrogen bond capacity than to dielectric constant of the considered solvents,clarifying the hydrogen bond capacity could be more important than dielectric constant in determining the kinetics of monoethanolamine with CO2.
基金supported by the National Natural Science Foundation of China (No.21936005)
文摘Predicting the logarithm of hexadecane/air partition coefficient(L)for organic compounds is crucial for understanding the environmental behavior and fate of organic compounds and developing prediction models with polyparameter linear free energy relationships.Herein,two quantitative structure activity relationship(QSAR)models were developed with 1272 L values for the organic compounds by using multiple linear regression(MLR)and support vector machine(SVM)algorithms.On the basis of the OECD principles,the goodness of fit,robustness and predictive ability for the developed models were evaluated.The SVM model was first developed,and the predictive capability for the SVM model is slightly better than that for the MLR model.The applicability domain(AD)of these two models has been extended to include more kinds of emerging pollutants,i.e.,oraganosilicon compounds.The developed QSAR models can be used for predicting L values of various organic compounds.The van derWaals interactions between the organic compound and the hexadecane have a significant effect on the L value of the compound.These in silico models developed in current study can provide an alternative to experimental method for high-throughput obtaining L values of organic compounds.
