Objective To explore the differential expression and mechanisms of bone formation-related genes in osteoporosis(OP)leveraging bioinformatics and machine learning methodologies;and to predict the active ingredients of ...Objective To explore the differential expression and mechanisms of bone formation-related genes in osteoporosis(OP)leveraging bioinformatics and machine learning methodologies;and to predict the active ingredients of targeted traditional Chinese medicine(TCM)herbs.Methods The Gene Expression Omnibus(GEO)and GeneCards databases were employed to conduct a comprehensive screening of genes and disease-associated loci pertinent to the pathogenesis of OP.The R package was utilized as the analytical tool for the identification of differentially expressed genes.Least absolute shrinkage and selection operator(LASSO)logis-tic regression analysis and support vector machine-recursive feature elimination(SVM-RFE)algorithm were employed in defining the genetic signature specific to OP.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses for the selected pivotal genes were conducted.The cell-type identification by estimating rela-tive subsets of RNA transcripts(CIBERSORT)algorithm was leveraged to examine the infiltra-tion patterns of immune cells;with Spearman’s rank correlation analysis utilized to assess the relationship between the expression levels of the genes and the presence of immune cells.Coremine Medical Database was used to screen out potential TCM herbs for the treatment of OP.Comparative Toxicogenomics Database(CTD)was employed for forecasting the TCM ac-tive ingredients targeting the key genes.AutoDock Vina 1.2.2 and GROMACS 2020 softwares were employed to conclude analysis results;facilitating the exploration of binding affinity and conformational dynamics between the TCM active ingredients and their biological targets.Results Ten genes were identified by intersecting the results from the GEO and GeneCards databases.Through the application of LASSO regression and SVM-RFE algorithm;four piv-otal genes were selected:coat protein(CP);kallikrein 3(KLK3);polymeraseγ(POLG);and transient receptor potential vanilloid 4(TRPV4).GO and KEGG pathway enrichment analy-ses revealed that these trait genes were predominantly engaged in the regulation of defense response activation;maintenance of cellular metal ion balance;and the production of chemokine ligand 5.These genes were notably associated with signaling pathways such as ferroptosis;porphyrin metabolism;and base excision repair.Immune infiltration analysis showed that key genes were highly correlated with immune cells.Macrophage M0;M1;M2;and resting dendritic cell were significantly different between groups;and there were signifi-cant differences between different groups(P<0.05).The interaction counts of resveratrol;curcumin;and quercetin with KLK3 were 7;3;and 2;respectively.It shows that the interac-tions of resveratrol;curcumin;and quercetin with KLK3 were substantial.Molecular docking and molecular dynamics simulations further confirmed the robust binding affinity of these bioactive compounds to the target genes.Conclusion Pivotal genes including CP;KLK3;POLG;and TRPV4;exhibited commendable significant prognostic value;and played a crucial role in the diagnostic assessment of OP.Resveratrol;curcumin;and quercetin;natural compounds found in TCM;showed promise in their potential to effectively modulate the bone-forming gene KLK3.This study provides a sci-entific basis for the interpretation of the pathogenesis of OP and the development of clinical drugs.展开更多
A novel precursor of nickel-cobalt alloy powders with an appropriate Ni to Co molar ratio was prepared under selectively synthetic conditions. The composition and morphology of the precursor were characterized by X-ra...A novel precursor of nickel-cobalt alloy powders with an appropriate Ni to Co molar ratio was prepared under selectively synthetic conditions. The composition and morphology of the precursor were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR) and energy dispersive spectrometry (EDS). The effects of pH value, reaction temperature, metal ion concentrations and surfactant on the morphology and the dispersion of precursor were investigated. The results show that the morphology of precursor depends on ammonia content in the precursor. A fibriform precursor is a complicated ammonia-containing nickel-cobalt oxalate. The uniform shape-controlled fibrous precursor is obtained under the following optimum conditions: ammonia as complex agent as well as pH adjustor, oxalate as coprecipitator, 50-65 °C of reaction temperature, 0.5-0.8 mol/L of total concentration of Ni2+ and Co2+, PVP as dispersant, and pH 8.0-8.4.展开更多
China's economic growth is heavily influenced by exports, while reconciling environmental regulation and economic growth requires handling the relationship between environmental regulation and industrial competitiven...China's economic growth is heavily influenced by exports, while reconciling environmental regulation and economic growth requires handling the relationship between environmental regulation and industrial competitiveness well. The effects of environmental regulation on industrial competitiveness are largely subject to the institutional design of environmental regulation. Despite numerous studies on the relationship between environmental regulation and industrial competitiveness, a consensus has yet to be reached. Aside from differences in research methodology, these studies failed to give sufficient consideration to the impact of environmental regulation on industrial competitiveness. Such effects can be negative or positive depending on the design of environmental regulatory policy. This paper has investigated the relationship between environmental regulation and the competitiveness of China's iron and steel industry and discovered that tighter environmental regulation does not diminish the competitiveness of the iron and steel industry since the policy design of environmental regulation accommodates the tolerance of advanced production capacity and includes a reasonable cost sharing mechanism. This discovery is of important reference for China to develop rational policy design to balance the relationship between environmental regulation and industrial competitiveness.展开更多
Oceanic front, especially Kuroshio front, is an important phenomenon that is of great significance for scientific research, national economy and military uses. However, Kuroshio front to the east of Taiwan (KFETW in ...Oceanic front, especially Kuroshio front, is an important phenomenon that is of great significance for scientific research, national economy and military uses. However, Kuroshio front to the east of Taiwan (KFETW in brief) was rare investigated. In this study, reanalysis method is used to study the KFETW's temporal and spatial variability and frontogenesis mechanism. It is found that although surface thermal front to the east of Taiwan is not obvious, there is an all-year strong Kuroshio thermal front called KFETW under the surface. The KFETW is connected to the south section of Kuroshio front in the East China Sea (KFECS in brief) and distributes along the east coastline of Taiwan. The KFETW has multi-scale variation feature. It has significant seasonal signal, and its intensity and width reach their maximum in summer. By using the reanalysis results obtained from this study, frontogenesis and changing mechanisms of the KFETW are discussed. It is found that both the Kuroshio and up-welling to the east of Taiwan can affect this front, and the up-welling may be the predominant factor in KFETW's frontogenesis and maintenance mechanism.展开更多
The formation mechanism for the body-centred regular icosahedral structure of Li13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes ...The formation mechanism for the body-centred regular icosahedral structure of Li13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li13 has been calculated by using the method of Gou's modified arrangement channel quantum mechanics (MACQM). The result shows that the curve has a minimal energy of-96.951 39 a.u. at R = 5.46ao. When R approaches to infinity, the total energy of thirteen lithium atoms has the value of-96.564 38 a.u. So the binding energy of Lii3 with respect to thirteen lithium atoms is 0.387 01 a.u. Therefore the binding energy per atom for Lii3 is 0.029 77 a.u. or 0.810 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, 0.494 eV for Li3, 0.7878 eV for Li4. 0.632 eV for Lis, and 0.674 eV for Liv calculated by us previously. This means that the Li13 cluster may be formed stably in a body-centred regular icosahedral structure with a greater binding energy.展开更多
Advances in clinical and fimdamental research, which have been promoted over last decades have led to a well- established understanding of atrial fibrillation (AF) as an epiphenomenon that despite similar manifestat...Advances in clinical and fimdamental research, which have been promoted over last decades have led to a well- established understanding of atrial fibrillation (AF) as an epiphenomenon that despite similar manifestations may have different underlying mechanisms and thus require in- dividualized treatments. With rare exceptions of AF caused by mutations in genes coding ion channels in pa- tients with structurally normal atria, fibrotic replacement of atrial myocardium remains the comer stone of atrial pa- thology in patients with AF.展开更多
To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized the albino mutant emb1303-1 in Arabidopsis. The mutant displayed a severe dwarf phenotype with small albino rose...To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized the albino mutant emb1303-1 in Arabidopsis. The mutant displayed a severe dwarf phenotype with small albino rosette leaves and short roots on a synthetic medium containing sucrose. It is pigment-deficient and seedling lethal when grown in soil. Embryo development was delayed in the mutant, although seed germination was not significantly impaired. The plastids of embl303-1 were arrested in early developmental stages without the classical stack of thylakoid membrane. Genetic and molecular analyses uncovered that the EMB1303 gene encodes a novel chloroplast-localized protein. Microarray and RT-PCR analyses revealed that a number of nuclear- and plastid-encoded genes involved in photosynthesis and chloroplast biogenesis were substantially downregulated in the mutant. Moreover, the accumulation of several major chloroplast proteins was severely compromised in emb1303-1. These results suggest that EMB1303 is essential for chloroplast development.展开更多
In this study, we compared the transcriptomes of Nannochloropsis oceanica cultured in f/2 medium prepared with seawater and freshwater, respectively, aiming to understand the acclimation mechanism of this alga to fres...In this study, we compared the transcriptomes of Nannochloropsis oceanica cultured in f/2 medium prepared with seawater and freshwater, respectively, aiming to understand the acclimation mechanism of this alga to freshwater. Differentially expressed genes were mainly assigned to the degradation of cell components, ion transportation, and ribosomal biogenesis. These find- ings indicate that the algal cells degrade its components (mainly amino acids and fatty acids) to yield excessive energy (ATP) to maintain cellular ion (mainly K+ and Ca〉) homeostasis, while the depletion of amino acids and ATP, and the reduction of ribosomes attenuate the protein translation and finally slow down the cell growth.展开更多
Atrial fibrosis is common in atrial fibrillation (AF). Experimental studies have provided convincing evidence that fibrotic transformation of atrial myocardium results in deterioration of atrial conduction, increasi...Atrial fibrosis is common in atrial fibrillation (AF). Experimental studies have provided convincing evidence that fibrotic transformation of atrial myocardium results in deterioration of atrial conduction, increasing anisotropy of impulse propagation and building of boundaries that promote re-entry in the atrial walls that maybe directly relevant for the mechanisms responsible for maintaining AF. Whether or not fibrosis is a result of structural remodelling caused by persistent AF or a manifestation of occult myocardial process that leads to development of arrhythmia is less clear. Human data indicate the presence of association between persistency of AF and the extent of structural changes in atrial myocardium. The role atrial fibrosis plays in the mechanisms of AF, however, may differ between patients with structurally normal hearts, such as lone AF, and those with advanced cardiovascular comorbidities.展开更多
Phosphorus (P) and metal (M) components were incorporated into promoters for enhancing FCC propylene yield, and the reactive behavior of promoters, before and after modification, were investigated. The results sho...Phosphorus (P) and metal (M) components were incorporated into promoters for enhancing FCC propylene yield, and the reactive behavior of promoters, before and after modification, were investigated. The results showed that both LPG and propylene yields were increased, and propylene selectivity was improved after the incorporation of P or M into the matrix, resulting in an increased C3 to C4 ratio in LPG during FCC process. But the sole incorporation of M into the matrix also led to an increase in coke and H2 yields on the other hand. Simultaneous modification of the matrix by P and M components resulted in more enhancement in propylene yield and selectivity along with little influence on FCC product distribution. Physico-chemical characterizations and model compound reactions were used to assist in analyzing the mechanism for improving propylene selectivity. Two types of active centers could strengthen the oligomerization of C4 olefins in LPG and these oligomers could be further cracked into C3 olefins on ZSM-5 zeolite, therefore maximizing the ratio of C3 to C4 in liquefied petroleum gas obtained during FCC process.展开更多
The radical-molecule reaction F+propene (CH2CHCH3) was studied in detail by using the Becke's three parameter Lee-Yang-Parr-B3LYP/6-311G(d,p) and coupled cluster with single, double, and triple excitationsCCSD(...The radical-molecule reaction F+propene (CH2CHCH3) was studied in detail by using the Becke's three parameter Lee-Yang-Parr-B3LYP/6-311G(d,p) and coupled cluster with single, double, and triple excitationsCCSD(T)/6-311+G(2d,2p). It is shown that F+propene reaction mainly occurs through complex-formation mechanism: F attacks the double bond of propene leading to the formation of complex 1 and complex 2. As the two radical complexes are metastable, they can quickly dissociate to H+C3HsF, CH3+C2H3F and HF+C3H5. Based on the ab initio calculations, the CH3+C2H3F is the main channel, and the H elimination and HF forming channels also provide some contribution to products. The calculated values are in good agreement with the recently reported experimental results.展开更多
The coal fire is one of very serious disasters in natural, not only amount of coal resources was burned and some ecological environment problems such as ground subsidence, acid rain, pollution and vegetation died were...The coal fire is one of very serious disasters in natural, not only amount of coal resources was burned and some ecological environment problems such as ground subsidence, acid rain, pollution and vegetation died were caused serious. The No.4 coal seam outcrops fire in Haibaoqing was take as research object, based on the existing theory of mechanism and characteristics of coal outcrop fires, a new fire-fighting composite gel is applicated which fits in with extinguishment of outcrop coal fires well. The technology has many advantages in extinguishing coal fires including isolating the coal from oxygen and lowering the temperature of the high-temperature coal and rock. The structure and chemical composition as well as fires-fighting properties of the composite gel is analyzed profoundly, as a result, reduce and stop the environment destruction caused by the coal fire.展开更多
Labroides dimidiatus has been proven to remove ectoparasites and monogeneans from client fishes and studies showed that they were not infected with the parasite. Due to this, there is a possibility that a defense mech...Labroides dimidiatus has been proven to remove ectoparasites and monogeneans from client fishes and studies showed that they were not infected with the parasite. Due to this, there is a possibility that a defense mechanism against pathogen and parasitic invasion exist in the epidermal mucus which serves as a mechanical as well as biochemical barrier. The study was performed to identify the amino acid and fatty acid components using GC (gas chromatography) and HPLC (high performance liquid chromatography) in epidermal mucus ofL. dimidiatus. The present study revealed 16 components of amino acid and 22 types of fatty acid in epidermal mucus ofL. dimidiatzts. Linoleic acid (C18:2n6c) was the most prominent PUFA (polyunsaturated fatty acid) which contributed approximately 11.69% of total fatty acids. The other major fatty acids are palmitic acid (C 16:0), oleic acid (C 18: l n9c), linoledaidic acid (C18:2n6t), arachidic acid (C20:0), Gamma-Linoleic acid (C18:3n6) and gadoleic acid (C20:1) which contained reasonable amounts of 9.52%, 8.06%, 6.26%, 8.33%, 6.21% and 9.05% of total fatty acids, respectively. This present study also demonstrated the presence of various amino acids in skin extract. Glycine, glutamine, arginine, asparagin and alanine were found at high concentration of 8.09%, 6.95%, 5.73%, 4.74%, 4.58% respectively. The most abundance percentage of linoleic acid (C18:2n6c) was found to be the metabolic precursor of arachidonic acid (AA) which inducing platelet aggregation, facilitate the blood clotting process and adhesion in endothelial cells during wound healing and might be responsible for rapid tissue growth in L. dimidiatus. It can be concluded that the amino acid and fatty acid profile from the epidermal mucus ofL. dimidiatus contains most of the essential components required to play a possible role in its defense mechanism. Understanding the biochemical properties of L. dimidiatus epidermal mucus in defense mechanism would enable to determine how this fish protect itself from parasitic infection.展开更多
As a fundamental component of the host cellular cytoskeleton, actin is routinely engaged by infecting viruses. Furthermore, viruses from diverse groups, and infecting diverse hosts, have convergently evolved an array ...As a fundamental component of the host cellular cytoskeleton, actin is routinely engaged by infecting viruses. Furthermore, viruses from diverse groups, and infecting diverse hosts, have convergently evolved an array of mechanisms for manipulating the actin cytoskeleton for efficacious infection. An ongoing chorus of research now indicates that the actin cytoskeleton is critical for viral replication at many stages of the viral life cycle, including binding, entry, nuclear localization, genomic transcription and reverse transcription, assembly, and egress/dissemination. Specifically, viruses subvert the force-generating and macromolecular scaffolding properties of the actin cytoskeleton to propel viral surfing, internalization, and migration within the cell. Additionally, viruses utilize the actin cytoskeleton to support and organize assembly sites, and eject budding virions for cell-to-cell transmission. It is the purpose of this review to provide an overview of current research, focusing on the various mechanisms and themes of virus-mediated actin modulation described therein.展开更多
Nowadays, the study of myths is rather neglected as a field of research in sociology. There is a void that this paper would like to contribute to filling. It outlines a theoretical and empirical sociological approach ...Nowadays, the study of myths is rather neglected as a field of research in sociology. There is a void that this paper would like to contribute to filling. It outlines a theoretical and empirical sociological approach to social myths as a major component of collective imaginaries and a universal sociological mechanism through time and space. The article recalls the major functions performed by myths in every society (modem as well as "primitive"), introduces new concepts, and sets forth an analytical framework designed to account for the emergence, the reproduction, and the decline of myths, as sacralised collective representations.展开更多
基金National Natural Science Foundation of China(81960877).
文摘Objective To explore the differential expression and mechanisms of bone formation-related genes in osteoporosis(OP)leveraging bioinformatics and machine learning methodologies;and to predict the active ingredients of targeted traditional Chinese medicine(TCM)herbs.Methods The Gene Expression Omnibus(GEO)and GeneCards databases were employed to conduct a comprehensive screening of genes and disease-associated loci pertinent to the pathogenesis of OP.The R package was utilized as the analytical tool for the identification of differentially expressed genes.Least absolute shrinkage and selection operator(LASSO)logis-tic regression analysis and support vector machine-recursive feature elimination(SVM-RFE)algorithm were employed in defining the genetic signature specific to OP.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses for the selected pivotal genes were conducted.The cell-type identification by estimating rela-tive subsets of RNA transcripts(CIBERSORT)algorithm was leveraged to examine the infiltra-tion patterns of immune cells;with Spearman’s rank correlation analysis utilized to assess the relationship between the expression levels of the genes and the presence of immune cells.Coremine Medical Database was used to screen out potential TCM herbs for the treatment of OP.Comparative Toxicogenomics Database(CTD)was employed for forecasting the TCM ac-tive ingredients targeting the key genes.AutoDock Vina 1.2.2 and GROMACS 2020 softwares were employed to conclude analysis results;facilitating the exploration of binding affinity and conformational dynamics between the TCM active ingredients and their biological targets.Results Ten genes were identified by intersecting the results from the GEO and GeneCards databases.Through the application of LASSO regression and SVM-RFE algorithm;four piv-otal genes were selected:coat protein(CP);kallikrein 3(KLK3);polymeraseγ(POLG);and transient receptor potential vanilloid 4(TRPV4).GO and KEGG pathway enrichment analy-ses revealed that these trait genes were predominantly engaged in the regulation of defense response activation;maintenance of cellular metal ion balance;and the production of chemokine ligand 5.These genes were notably associated with signaling pathways such as ferroptosis;porphyrin metabolism;and base excision repair.Immune infiltration analysis showed that key genes were highly correlated with immune cells.Macrophage M0;M1;M2;and resting dendritic cell were significantly different between groups;and there were signifi-cant differences between different groups(P<0.05).The interaction counts of resveratrol;curcumin;and quercetin with KLK3 were 7;3;and 2;respectively.It shows that the interac-tions of resveratrol;curcumin;and quercetin with KLK3 were substantial.Molecular docking and molecular dynamics simulations further confirmed the robust binding affinity of these bioactive compounds to the target genes.Conclusion Pivotal genes including CP;KLK3;POLG;and TRPV4;exhibited commendable significant prognostic value;and played a crucial role in the diagnostic assessment of OP.Resveratrol;curcumin;and quercetin;natural compounds found in TCM;showed promise in their potential to effectively modulate the bone-forming gene KLK3.This study provides a sci-entific basis for the interpretation of the pathogenesis of OP and the development of clinical drugs.
基金Project (20090162120080) supported by Doctoral Fund of Ministry of Education, ChinaProject (20070410989) supported by China Postdoctoral Science FoundationProject(748310000) supported by Central South University Science Foundation for Youths, China
文摘A novel precursor of nickel-cobalt alloy powders with an appropriate Ni to Co molar ratio was prepared under selectively synthetic conditions. The composition and morphology of the precursor were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR) and energy dispersive spectrometry (EDS). The effects of pH value, reaction temperature, metal ion concentrations and surfactant on the morphology and the dispersion of precursor were investigated. The results show that the morphology of precursor depends on ammonia content in the precursor. A fibriform precursor is a complicated ammonia-containing nickel-cobalt oxalate. The uniform shape-controlled fibrous precursor is obtained under the following optimum conditions: ammonia as complex agent as well as pH adjustor, oxalate as coprecipitator, 50-65 °C of reaction temperature, 0.5-0.8 mol/L of total concentration of Ni2+ and Co2+, PVP as dispersant, and pH 8.0-8.4.
文摘China's economic growth is heavily influenced by exports, while reconciling environmental regulation and economic growth requires handling the relationship between environmental regulation and industrial competitiveness well. The effects of environmental regulation on industrial competitiveness are largely subject to the institutional design of environmental regulation. Despite numerous studies on the relationship between environmental regulation and industrial competitiveness, a consensus has yet to be reached. Aside from differences in research methodology, these studies failed to give sufficient consideration to the impact of environmental regulation on industrial competitiveness. Such effects can be negative or positive depending on the design of environmental regulatory policy. This paper has investigated the relationship between environmental regulation and the competitiveness of China's iron and steel industry and discovered that tighter environmental regulation does not diminish the competitiveness of the iron and steel industry since the policy design of environmental regulation accommodates the tolerance of advanced production capacity and includes a reasonable cost sharing mechanism. This discovery is of important reference for China to develop rational policy design to balance the relationship between environmental regulation and industrial competitiveness.
基金supported by grants of the National Basic Research Program of China(No.2007CB816001)the National Natural Science Foundation of China (No.41030854,40906016 and 40906015)
文摘Oceanic front, especially Kuroshio front, is an important phenomenon that is of great significance for scientific research, national economy and military uses. However, Kuroshio front to the east of Taiwan (KFETW in brief) was rare investigated. In this study, reanalysis method is used to study the KFETW's temporal and spatial variability and frontogenesis mechanism. It is found that although surface thermal front to the east of Taiwan is not obvious, there is an all-year strong Kuroshio thermal front called KFETW under the surface. The KFETW is connected to the south section of Kuroshio front in the East China Sea (KFECS in brief) and distributes along the east coastline of Taiwan. The KFETW has multi-scale variation feature. It has significant seasonal signal, and its intensity and width reach their maximum in summer. By using the reanalysis results obtained from this study, frontogenesis and changing mechanisms of the KFETW are discussed. It is found that both the Kuroshio and up-welling to the east of Taiwan can affect this front, and the up-welling may be the predominant factor in KFETW's frontogenesis and maintenance mechanism.
基金supported by National Natural Science Foundation of China under Grant No.19974027
文摘The formation mechanism for the body-centred regular icosahedral structure of Li13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li13 has been calculated by using the method of Gou's modified arrangement channel quantum mechanics (MACQM). The result shows that the curve has a minimal energy of-96.951 39 a.u. at R = 5.46ao. When R approaches to infinity, the total energy of thirteen lithium atoms has the value of-96.564 38 a.u. So the binding energy of Lii3 with respect to thirteen lithium atoms is 0.387 01 a.u. Therefore the binding energy per atom for Lii3 is 0.029 77 a.u. or 0.810 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, 0.494 eV for Li3, 0.7878 eV for Li4. 0.632 eV for Lis, and 0.674 eV for Liv calculated by us previously. This means that the Li13 cluster may be formed stably in a body-centred regular icosahedral structure with a greater binding energy.
文摘Advances in clinical and fimdamental research, which have been promoted over last decades have led to a well- established understanding of atrial fibrillation (AF) as an epiphenomenon that despite similar manifestations may have different underlying mechanisms and thus require in- dividualized treatments. With rare exceptions of AF caused by mutations in genes coding ion channels in pa- tients with structurally normal atria, fibrotic replacement of atrial myocardium remains the comer stone of atrial pa- thology in patients with AF.
文摘To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized the albino mutant emb1303-1 in Arabidopsis. The mutant displayed a severe dwarf phenotype with small albino rosette leaves and short roots on a synthetic medium containing sucrose. It is pigment-deficient and seedling lethal when grown in soil. Embryo development was delayed in the mutant, although seed germination was not significantly impaired. The plastids of embl303-1 were arrested in early developmental stages without the classical stack of thylakoid membrane. Genetic and molecular analyses uncovered that the EMB1303 gene encodes a novel chloroplast-localized protein. Microarray and RT-PCR analyses revealed that a number of nuclear- and plastid-encoded genes involved in photosynthesis and chloroplast biogenesis were substantially downregulated in the mutant. Moreover, the accumulation of several major chloroplast proteins was severely compromised in emb1303-1. These results suggest that EMB1303 is essential for chloroplast development.
基金financially supported by the National Natural Science Foundation of China(31270408)National High Technology Research and Development Program(863 Program)of China(2014AA022001)
文摘In this study, we compared the transcriptomes of Nannochloropsis oceanica cultured in f/2 medium prepared with seawater and freshwater, respectively, aiming to understand the acclimation mechanism of this alga to freshwater. Differentially expressed genes were mainly assigned to the degradation of cell components, ion transportation, and ribosomal biogenesis. These find- ings indicate that the algal cells degrade its components (mainly amino acids and fatty acids) to yield excessive energy (ATP) to maintain cellular ion (mainly K+ and Ca〉) homeostasis, while the depletion of amino acids and ATP, and the reduction of ribosomes attenuate the protein translation and finally slow down the cell growth.
文摘Atrial fibrosis is common in atrial fibrillation (AF). Experimental studies have provided convincing evidence that fibrotic transformation of atrial myocardium results in deterioration of atrial conduction, increasing anisotropy of impulse propagation and building of boundaries that promote re-entry in the atrial walls that maybe directly relevant for the mechanisms responsible for maintaining AF. Whether or not fibrosis is a result of structural remodelling caused by persistent AF or a manifestation of occult myocardial process that leads to development of arrhythmia is less clear. Human data indicate the presence of association between persistency of AF and the extent of structural changes in atrial myocardium. The role atrial fibrosis plays in the mechanisms of AF, however, may differ between patients with structurally normal hearts, such as lone AF, and those with advanced cardiovascular comorbidities.
文摘Phosphorus (P) and metal (M) components were incorporated into promoters for enhancing FCC propylene yield, and the reactive behavior of promoters, before and after modification, were investigated. The results showed that both LPG and propylene yields were increased, and propylene selectivity was improved after the incorporation of P or M into the matrix, resulting in an increased C3 to C4 ratio in LPG during FCC process. But the sole incorporation of M into the matrix also led to an increase in coke and H2 yields on the other hand. Simultaneous modification of the matrix by P and M components resulted in more enhancement in propylene yield and selectivity along with little influence on FCC product distribution. Physico-chemical characterizations and model compound reactions were used to assist in analyzing the mechanism for improving propylene selectivity. Two types of active centers could strengthen the oligomerization of C4 olefins in LPG and these oligomers could be further cracked into C3 olefins on ZSM-5 zeolite, therefore maximizing the ratio of C3 to C4 in liquefied petroleum gas obtained during FCC process.
基金Ⅴ. ACKN0WLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20328304, No.10574068, No.20533060 and No.20525313).
文摘The radical-molecule reaction F+propene (CH2CHCH3) was studied in detail by using the Becke's three parameter Lee-Yang-Parr-B3LYP/6-311G(d,p) and coupled cluster with single, double, and triple excitationsCCSD(T)/6-311+G(2d,2p). It is shown that F+propene reaction mainly occurs through complex-formation mechanism: F attacks the double bond of propene leading to the formation of complex 1 and complex 2. As the two radical complexes are metastable, they can quickly dissociate to H+C3HsF, CH3+C2H3F and HF+C3H5. Based on the ab initio calculations, the CH3+C2H3F is the main channel, and the H elimination and HF forming channels also provide some contribution to products. The calculated values are in good agreement with the recently reported experimental results.
文摘The coal fire is one of very serious disasters in natural, not only amount of coal resources was burned and some ecological environment problems such as ground subsidence, acid rain, pollution and vegetation died were caused serious. The No.4 coal seam outcrops fire in Haibaoqing was take as research object, based on the existing theory of mechanism and characteristics of coal outcrop fires, a new fire-fighting composite gel is applicated which fits in with extinguishment of outcrop coal fires well. The technology has many advantages in extinguishing coal fires including isolating the coal from oxygen and lowering the temperature of the high-temperature coal and rock. The structure and chemical composition as well as fires-fighting properties of the composite gel is analyzed profoundly, as a result, reduce and stop the environment destruction caused by the coal fire.
文摘Labroides dimidiatus has been proven to remove ectoparasites and monogeneans from client fishes and studies showed that they were not infected with the parasite. Due to this, there is a possibility that a defense mechanism against pathogen and parasitic invasion exist in the epidermal mucus which serves as a mechanical as well as biochemical barrier. The study was performed to identify the amino acid and fatty acid components using GC (gas chromatography) and HPLC (high performance liquid chromatography) in epidermal mucus ofL. dimidiatus. The present study revealed 16 components of amino acid and 22 types of fatty acid in epidermal mucus ofL. dimidiatzts. Linoleic acid (C18:2n6c) was the most prominent PUFA (polyunsaturated fatty acid) which contributed approximately 11.69% of total fatty acids. The other major fatty acids are palmitic acid (C 16:0), oleic acid (C 18: l n9c), linoledaidic acid (C18:2n6t), arachidic acid (C20:0), Gamma-Linoleic acid (C18:3n6) and gadoleic acid (C20:1) which contained reasonable amounts of 9.52%, 8.06%, 6.26%, 8.33%, 6.21% and 9.05% of total fatty acids, respectively. This present study also demonstrated the presence of various amino acids in skin extract. Glycine, glutamine, arginine, asparagin and alanine were found at high concentration of 8.09%, 6.95%, 5.73%, 4.74%, 4.58% respectively. The most abundance percentage of linoleic acid (C18:2n6c) was found to be the metabolic precursor of arachidonic acid (AA) which inducing platelet aggregation, facilitate the blood clotting process and adhesion in endothelial cells during wound healing and might be responsible for rapid tissue growth in L. dimidiatus. It can be concluded that the amino acid and fatty acid profile from the epidermal mucus ofL. dimidiatus contains most of the essential components required to play a possible role in its defense mechanism. Understanding the biochemical properties of L. dimidiatus epidermal mucus in defense mechanism would enable to determine how this fish protect itself from parasitic infection.
基金supported by US Public Health Service grant 1R01MH102144 from NIMH to Y. W
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