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1.
Nano Lett ; 24(15): 4433-4438, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38564276

RESUMEN

Twisted bilayer graphene (TBG) has the natural merits of tunable flat bands and localized states distributed as a triangular lattice. However, the application of this state remains obscure. By density functional theory (DFT) and pz orbital tight-binding model calculations, we investigate the tip-shaped electrostatic potential of top valence electrons of TBG at half filling. Adsorption energy scanning of molecules above the TBG reveals that this tip efficiently attracts molecules selectively to AA-stacked or AB-stacked regions. Tip shapes can be controlled by their underlying electronic structure, with electrons of low bandwidth exhibiting a more localized feature. Our results indicate that TBG tips offer applications in noninvasive and nonpolluting measurements in scanning probe microscopy and theoretical guidance for 2D material-based probes.

2.
Funct Integr Genomics ; 24(1): 26, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38329581

RESUMEN

The medicinal herb Artemisia annua L. is prized for its capacity to generate artemisinin, which is used to cure malaria. Potentially influencing the biomass and secondary metabolite synthesis of A. annua is plant nutrition, particularly phosphorus (P). However, most soil P exist as insoluble inorganic and organic phosphates, which results to low P availability limiting plant growth and development. Although plants have developed several adaptation strategies to low P levels, genetics and metabolic responses to P status remain largely unknown. In a controlled greenhouse experiment, the sparingly soluble P form, hydroxyapatite (Ca5OH(PO4)3/CaP) was used to simulate calcareous soils with low P availability. In contrast, the soluble P form KH2PO4/KP was used as a control. A. annua's morphological traits, growth, and artemisinin concentration were determined, and RNA sequencing was used to identify the differentially expressed genes (DEGs) under two different P forms. Total biomass, plant height, leaf number, and stem diameter, as well as leaf area, decreased by 64.83%, 27.49%, 30.47%, 38.70%, and 54.64% in CaP compared to KP; however, LC-MS tests showed an outstanding 37.97% rise in artemisinin content per unit biomass in CaP contrary to KP. Transcriptome analysis showed 2015 DEGs (1084 up-regulated and 931 down-regulated) between two P forms, including 39 transcription factor (TF) families. Further analysis showed that DEGs were mainly enriched in carbohydrate metabolism, secondary metabolites biosynthesis, enzyme catalytic activity, signal transduction, and so on, such as tricarboxylic acid (TCA) cycle, glycolysis, starch and sucrose metabolism, flavonoid biosynthesis, P metabolism, and plant hormone signal transduction. Meanwhile, several artemisinin biosynthesis genes were up-regulated, including DXS, GPPS, GGPS, MVD, and ALDH, potentially increasing artemisinin accumulation. Furthermore, 21 TF families, including WRKY, MYB, bHLH, and ERF, were up-regulated in reaction to CaP, confirming their importance in P absorption, internal P cycling, and artemisinin biosynthesis regulation. Our results will enable us to comprehend how low P availability impacts the parallel transcriptional control of plant development, growth, and artemisinin production in A. annua. This study could lay the groundwork for future research into the molecular mechanisms underlying A. annua's low P adaptation.


Asunto(s)
Artemisia annua , Artemisininas , Artemisia annua/genética , Fertilizantes , Perfilación de la Expresión Génica , Lagos , Fósforo
3.
J Phys Chem A ; 128(10): 1925-1937, 2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38430107

RESUMEN

K-means clustering, as a classic unsupervised machine learning algorithm, is the key step to select the interpolation sampling points in interpolative separable density fitting (ISDF) decomposition for hybrid functional electronic structure calculations. Real-valued K-means clustering for accelerating the ISDF decomposition has been demonstrated for large-scale hybrid functional enabled ab initio molecular dynamics (hybrid AIMD) simulations within plane-wave basis sets where the Kohn-Sham orbitals are real-valued. However, it is unclear whether such K-means clustering works for complex-valued Kohn-Sham orbitals. Here, we propose an improved weight function defined as the sum of the square modulus of complex-valued Kohn-Sham orbitals in K-means clustering for hybrid AIMD simulations. Numerical results demonstrate that the K-means algorithm with a new weight function yields smoother and more delocalized interpolation sampling points, resulting in smoother energy potential, smaller energy drift, and longer time steps for hybrid AIMD simulations compared to the previous weight function used in the real-valued K-means algorithm. In particular, we find that this improved algorithm can obtain more accurate oxygen-oxygen radial distribution functions in liquid water molecules and a more accurate power spectrum in crystal silicon dioxide compared to the previous K-means algorithm. Finally, we describe a massively parallel implementation of this ISDF decomposition to accelerate large-scale complex-valued hybrid AIMD simulations containing thousands of atoms (2,744 atoms), which can scale up to 5,504 CPU cores on modern supercomputers.

4.
J Phys Chem A ; 128(10): 1913-1924, 2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38439159

RESUMEN

Density functional perturbation theory (DFPT) is a crucial tool for accurately describing lattice dynamics. The adaptively compressed polarizability (ACP) method reduces the computational complexity of DFPT calculations from O(N4) to O(N3) by combining the interpolative separable density fitting (ISDF) algorithm. However, the conventional QR factorization with column pivoting (QRCP) algorithm, used for selecting the interpolation points in ISDF, not only incurs a high cubic-scaling computational cost, O(N3), but also leads to suboptimal convergence. This convergence issue is particularly pronounced when considering the complex interplay between the external potential and atomic displacement in ACP-based DFPT calculations. Here, we present a machine learning K-means clustering algorithm to select the interpolation points in ISDF, which offers a more efficient quadratic-scaling O(N2) alternative to the computationally intensive cubic-scaling O(N3) QRCP algorithm. We implement this efficient K-means-based ISDF algorithm to accelerate plane-wave DFPT calculations in KSSOLV, which is a MATLAB toolbox for performing Kohn-Sham density functional theory calculations within plane waves. We demonstrate that this K-means algorithm not only offers comparable accuracy to QRCP in ISDF but also achieves better convergence for ACP-based DFPT calculations. In particular, K-means can remarkably reduce the computational cost of selecting the interpolation points by nearly 2 orders of magnitude compared to QRCP in ISDF.

5.
Funct Integr Genomics ; 23(2): 141, 2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-37118364

RESUMEN

Artemisia annua L. is a medicinal plant valued for its ability to produce artemisinin, a molecule used to treat malaria. Plant nutrients, especially phosphorus (P), can potentially influence plant biomass and secondary metabolite production. Our work aimed to explore the genetic and metabolic response of A. annua to hardly soluble aluminum phosphate (AlPO4, AlP), using soluble monopotassium phosphate (KH2PO4, KP) as a control. Liquid chromatography-mass spectrometry (LC-MS) was used to analyze artemisinin. RNA sequencing, gene ontology (GO), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were applied to analyze the differentially expressed genes (DEGs) under poor P conditions. Results showed a significant reduction in plant growth parameters, such as plant height, stem diameter, number of leaves, leaf areas, and total biomass of A. annua. Conversely, LC-MS analysis revealed a significant increase in artemisinin concentration under the AlP compared to the KP. Transcriptome analysis revealed 762 differentially expressed genes (DEGs) between the AlP and the KP. GH3, SAUR, CRE1, and PYL, all involved in plant hormone signal transduction, showed differential expression. Furthermore, despite the downregulation of HMGR in the artemisinin biosynthesis pathway, the majority of genes (ACAT, FPS, CYP71AV1, and ALDH1) were upregulated, resulting in increased artemisinin accumulation in the AlP. In addition, 12 transcription factors, including GATA and MYB, were upregulated in response to AlP, confirming their importance in regulating artemisinin biosynthesis. Overall, our findings could contribute to a better understanding the parallel transcriptional regulation of plant hormone transduction and artemisinin biosynthesis in A. annua L. in response to hardly soluble phosphorus fertilizer.


Asunto(s)
Artemisia annua , Artemisininas , Artemisia annua/genética , Artemisia annua/química , Artemisia annua/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Artemisininas/química , Artemisininas/metabolismo , Fosfatos/metabolismo , Análisis de Secuencia de ARN , Fósforo/metabolismo
6.
BMC Microbiol ; 23(1): 128, 2023 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-37173641

RESUMEN

BACKGROUND: To explore the community composition and diversity of the endophytic fungi in Taxillus chinensis, samples of the parasites growing on seven different hosts, Morus alba, Prunus salicina, Phellodendron chinense, Bauhinia purpurea, Dalbergia odorifera, Diospyros kaki and Dimocarpus longan, were isolated. The strains were identified by their morphological characteristics and their internal transcribed spacer (ITS) sequences. RESULTS: 150 different endophytic fungi were isolated from the haustorial roots of the seven hosts with a total isolation rate of 61.24%. These endophytic fungi were found to belong to 1 phylum, 2 classes, 7 orders, 9 families, 11 genera and 8 species. Among of them, Pestalotiopsis, Neopestalotiopsis and Diaporthe were the dominant genera, accounting for 26.67, 17.33 and 31.33% of the total number of strains, respectively. Diversity and similarity analyses showed that the endophytic fungi isolated from D. longan (H'=1.60) had the highest diversity index. The highest richness indexes were found in M. alba and D. odorifera (both 2.23). The evenness index of D. longan was the highest (0.82). The similarity coefficient of D. odorifera was the most similar to D. longan and M. alba (33.33%), while the similarity coefficient of P. chinense was the lowest (7.69%) with M. alba and D. odorifera. Nine strains showed antimicrobial activities. Among them, Pestalotiopsis sp., N. parvum and H. investiens showed significant antifungal activity against three fungal phytopathogens of medicinal plants. At the same time, the crude extracts from the metabolites of the three endophytic fungi had strong inhibitory effects on the three pathogens. Pestalotiopsis sp., N. parvum and H. investiens had the strongest inhibitory effects of S. cucurbitacearum, with inhibitory rates of 100%, 100% and 81.51%, respectively. In addition, N. parvum had a strong inhibitory effect on D. glomerata and C. cassicola, with inhibitory rates of 82.35% and 72.80%, respectively. CONCLUSIONS: These results indicate that the species composition and diversity of endophytic fungi in the branches of T. chinensis were varied in the different hosts and showed good antimicrobial potential in the control of plant pathogens.


Asunto(s)
Antiinfecciosos , Loranthaceae , Humanos , Hongos , Endófitos , Biodiversidad , Filogenia
7.
Sensors (Basel) ; 23(13)2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37447837

RESUMEN

There are multiple types of services in the Internet of Things, and existing access control methods do not consider situations wherein the same types of services have multiple access options. In order to ensure the QoS quality of user access and realize the reasonable utilization of Internet of Things network resources, it is necessary to consider the characteristics of different services to design applicable access control strategies. In this paper, a preference-aware user access control strategy in slices is proposed, which can increase the number of users in the system while balancing slice resource utilization. First, we establish the user QoS model and slice QoS index range according to the delay, rate and reliability requirements, and we select users with multiple access options. Secondly, a user preference matrix is established according to the user QoS requirements and the slice QoS index range. Finally, a preference matrix of the slice is built according to the optimization objective, and access control decisions are made for users through the resource utilization state of the slice and the preference matrix. The verification results show that the proposed strategy not only balances slice resource utilization but also increases the number of users who can access the system.


Asunto(s)
Internet de las Cosas , Reproducibilidad de los Resultados , Concienciación , Internet
8.
Int J Mol Sci ; 24(4)2023 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-36835049

RESUMEN

Protoplast-based engineering has become an important tool for basic plant molecular biology research and developing genome-edited crops. Uncaria rhynchophylla is a traditional Chinese medicinal plant with a variety of pharmaceutically important indole alkaloids. In this study, an optimized protocol for U. rhynchophylla protoplast isolation, purification, and transient gene expression was developed. The best protoplast separation protocol was found to be 0.8 M D-mannitol, 1.25% Cellulase R-10, and 0.6% Macerozyme R-10 enzymolysis for 5 h at 26 °C in the dark with constant oscillation at 40 rpm/min. The protoplast yield was as high as 1.5 × 107 protoplasts/g fresh weight, and the survival rate of protoplasts was greater than 90%. Furthermore, polyethylene glycol (PEG)-mediated transient transformation of U. rhynchophylla protoplasts was investigated by optimizing different crucial factors affecting transfection efficiency, including plasmid DNA amount, PEG concentration, and transfection duration. The U. rhynchophylla protoplast transfection rate was highest (71%) when protoplasts were transfected overnight at 24 °C with the 40 µg of plasmid DNA for 40 min in a solution containing 40% PEG. This highly efficient protoplast-based transient expression system was used for subcellular localization of transcription factor UrWRKY37. Finally, a dual-luciferase assay was used to detect a transcription factor promoter interaction by co-expressing UrWRKY37 with a UrTDC-promoter reporter plasmid. Taken together, our optimized protocols provide a foundation for future molecular studies of gene function and expression in U. rhynchophylla.


Asunto(s)
Perfilación de la Expresión Génica , Protoplastos , Protoplastos/metabolismo , Perfilación de la Expresión Génica/métodos , Factores de Transcripción/metabolismo , ADN/metabolismo
9.
Nano Lett ; 21(1): 740-746, 2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33356331

RESUMEN

Spin field-effect transistors (SFETs) based on the Rashba effect could manipulate the spin of electrons electrically, while seeking desirable Rashba semiconductors with large Rashba constant and strong electric-field response, to preserve spin coherence remains a key challenge. Herein, we propose a series of 2D Rashba semiconductors with two-atom-thick buckled honeycomb structure (BHS) according to high-throughput first-principles density functional theory calculations. BHS semiconductors show large Rashba constants that are favorable to be integrated into nanodevices superior to conventional bulk materials, and they can be fabricated by mechanical exfoliation or chemical vapor deposition. In particular, 2D AlBi monolayer has the largest Rashba constant (2.77 eVÅ) of all 2D Rashba materials. Furthermore, 2D BiSb monolayer is a promising candidate for SFETs due to its large Rashba constant (1.94 eVÅ) and strong electric field response (0.92 eÅ2). Our designed 2D-BiSb-SFET shows shorter spin channel length (42 nm with strain) than conventional SFETs (2-5 µm).

10.
J Phys Chem A ; 125(34): 7545-7557, 2021 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-34428038

RESUMEN

The GW approximation is an effective way to accurately describe the single-electron excitations of molecules and the quasiparticle energies of solids. However, a perceived drawback of the GW calculations is their high computational cost and large memory usage, which limit their applications to large systems. Herein, we demonstrate an accurate and effective low-rank approximation to accelerate non-self-consistent GW (G0W0) calculations under the static Coulomb hole plus screened exchange (COHSEX) approximation for periodic systems. Our approach is to adopt the interpolative separable density fitting (ISDF) decomposition and Cauchy's integral to construct low-rank representations of the dielectric matrix ϵ and self-energy matrix Σ. This approach reduces the number of floating point operations from O(Ne4) to O(Ne3) and requires a much smaller memory footprint. Two methods are used to select the interpolation points in ISDF, including the standard QR factorization with column pivoting (QRCP) procedure and the machine learning K-means clustering (K-means) algorithm. We demonstrate that these two methods can yield similar accuracy for both molecules and solids at much lower computational cost. In particular, K-means clustering can significantly reduce the computational cost of selecting the interpolation points by an order of magnitude compared to QRCP, resulting in an overall speedup factor of about ten times ISDF accelerated the static COHSEX calculations compared with conventional COHSEX approximation.

11.
Oecologia ; 192(2): 415-423, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31865483

RESUMEN

The Novel Defense Hypothesis predicts that introduced plants may possess novel allelochemicals which act as a defense against native generalist enemies. Here, we aim to test if the chemicals involved in allelopathy in the invasive plant Wedelia trilobata can contribute to higher resistance against generalist herbivore and pathogen enemies by comparing with its native congener W. chinensis in controlled laboratory conditions. The allelopathic effects of the leaf extract from W. trilobata on the generalist enemies were also assessed. We showed that the larvae of two moth species preferred W. chinensis over W. trilobata. The growth rate of larvae feeding on W. trilobata leaves was significantly lower than those feeding on W. chinensis leaves. When detached leaves were inoculated with phytopathogens, the infected leaf area of W. trilobata was significantly smaller than that of W. chinensis. In addition, the leaf extract of W. trilobata also effectively inhibited the growth of the larvae and the mycelial growth of the phytopathogens. Our results indicate that the defenses of invasive W. trilobata against generalist herbivore and pathogen enemies are stronger than that of its native congener, which may be attributed to the allelopathic effects. This study provides novel insights that can comprehensively link the Novel Defense, Behavioral Constraint and Enemy Release hypotheses. These combined hypotheses would explain how invasive plants escape from their natural specialist enemies, where their allelopathic chemicals may deter herbivorous insects and inhibit pathogen infection.


Asunto(s)
Asteraceae , Wedelia , Alelopatía , Animales , Herbivoria , Larva
12.
J Reprod Infant Psychol ; 36(2): 158-167, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29517339

RESUMEN

OBJECTIVES: The reaction of firstborns to the impending arrival of a sibling has received little attention from family psychologists. The present study examined whether firstborns' positive feelings about their sibling before the birth were related to the time at which they were told about the mother's pregnancy and their effortful control, which was defined as the self-regulatory ability to inhibit a dominant response to perform a subdominant response. The goal of this research was to provide preliminary evidence in the social context of the two-child policy in China. METHODS: The sample included 52 Chinese parents and their firstborns when mothers were in their third trimester of pregnancy with their second child. Data were obtained by means of observation and parent-reported questionnaires. RESULTS: Firstborn children who were told earlier in their mothers' pregnancy were more likely to have positive feelings about their sibling before the birth. In addition, firstborns' effortful control was positively associated with positive feelings about a sibling before the birth. Last, firstborns' effortful control moderated the association between the time at which they were told and positive feelings about the sibling before the birth. Specifically, only when firstborns had low levels of effortful control, being told later about the pregnancy, was related to lower levels of positive feelings about the sibling. CONCLUSIONS: Findings enhanced our understanding of how parents' preparation and firstborns' individual characteristics may have a role on firstborns' positive adjustment before the birth of a sibling.


Asunto(s)
Orden de Nacimiento/psicología , Madres/psicología , Parto/psicología , Hermanos/psicología , Revelación de la Verdad , Niño , Conducta Infantil , Preescolar , China , Femenino , Humanos , Masculino , Responsabilidad Parental , Embarazo , Encuestas y Cuestionarios , Factores de Tiempo
13.
Zhongguo Zhong Yao Za Zhi ; 42(14): 2649-2654, 2017 Jul.
Artículo en Zh | MEDLINE | ID: mdl-29098817

RESUMEN

A comprehensive field research had been focused on growing status, underground biomass and active constituents of Notopterygium incisum and N. franchetii to evaluate the ecological suitability and appropriate cultivation zones by growing the two species seedlings along different elevation gradient. The results showed that compared to the survival rate and underground biomass, the beneficial altitude region to N. incisum was ranged from 2 600 m to 4 100 m, while N. franchetii required a lower altitude which ranges from 1 700 m to 3 600 m. For the active constituent contents, the values were higher in the range of 2 600 to 3 600 m for N. incisum, but for N. franchetii, the range was form 1 700 to 3 600 m. This result provides instructional guidance and scientific basis for artificial cultivation of N. incisum and N. franchetii.


Asunto(s)
Altitud , Apiaceae/crecimiento & desarrollo , Producción de Cultivos , Plantas Medicinales/crecimiento & desarrollo , Biomasa , Ecología
14.
Zhongguo Zhong Yao Za Zhi ; 42(14): 2645-2648, 2017 Jul.
Artículo en Zh | MEDLINE | ID: mdl-29098816

RESUMEN

In this study,field cultivation experiments of Notopterygium incisum had been carried out for three years, and samples had been collected monthly during growth seasons, and biomass and nutrient elements of aerial and underground part of sampled plants had been determined to assess their seasonal and interannual dynamics respectively. The results showed that biomass of underground part (dry weight) increased mainly in the second year after seedling transplanting, i.e., biomass increased about 32 times in the second year whilst less than 6 times and 2 times in the first year and in the third year, respectively. Therefore, efforts for yield improvement should be focused on the first two year in artificial cultivation of N. incisum. Accumulation of nutrient elements increased steady in the underground part during the first and second year, then showed a sharp decline in the first phase of growth season in the third year, while its accumulation in July to August of third year was higher than the value of second year. Ca, Fe, B and Zn were larger demand nutrient elements to meet growth demands whether for the underground part or aerial part during the second year and third year for N. incisum cultivation. This result provided instructional guidance and scientific basis for artificial cultivation and specific fertilizer of N. incisum.


Asunto(s)
Apiaceae/química , Nutrientes , Plantas Medicinales/química , Biomasa , Producción de Cultivos , Fertilizantes
15.
J Cell Mol Med ; 20(7): 1329-38, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26987780

RESUMEN

Periodontitis is a chronic inflammatory disease which is caused by bacterial infection and leads to the destruction of periodontal tissues and resorption of alveolar bone. Thus, special attention should be paid to the mechanism under lipopolysaccharide (LPS)-induced periodontitis because LPS is the major cause of periodontitis. However, to date, miRNA expression in the LPS-induced periodontitis has not been well characterized. In this study, we investigated miRNA expression patterns in LPS-treated periodontal ligament cells (PDLCs). Through miRNA array and differential analysis, 22 up-regulated miRNAs and 28 down-regulated miRNAs in LPS-treated PDLCs were identified. Seven randomly selected up-regulated (miR-21-5p, 498, 548a-5p) and down-regulated (miR-495-3p, 539-5p, 34c-3p and 7a-2-3p) miRNAs were examined by qRT-PCR, and the results proved the accuracy of the miRNA array. Moreover, targets of these deregulated miRNAs were analysed using the miRWalk database. Database for Annotation, Visualization and Integration Discovery software were performed to analyse the Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes pathway of differential expression miRNAs, and the results shown that Toll-like receptor signalling pathway, cAMP signalling pathway, transforming growth factor-beta signalling pathway, mitogen-activated protein kinase (MAPK) signalling pathway and other pathways were involved in the molecular mechanisms underlying LPS-induced periodontitis. In conclusion, this study provides clues for enhancing our understanding of the mechanisms and roles of miRNAs as key regulators of LPS-induced periodontitis.


Asunto(s)
Perfilación de la Expresión Génica , Lipopolisacáridos/farmacología , MicroARNs/genética , Ligamento Periodontal/citología , Porphyromonas gingivalis/química , Proliferación Celular/efectos de los fármacos , Análisis por Conglomerados , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Ontología de Genes , Redes Reguladoras de Genes , Humanos , MicroARNs/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Transducción de Señal/genética , Factores de Tiempo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
16.
J Chem Ecol ; 42(2): 85-94, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26879680

RESUMEN

The invasive clonal plant Wedelia trilobata contains higher levels of ent-kaurane diterpenes, which are precursors of gibberellins (GAs), and higher rates of clonal growth than its native congener W. chinensis in invaded habitats. We hypothesized that the higher levels of endogenous GAs facilitate greater ramet growth in W. trilobata compared with W. chinensis. We quantified endogenous levels of GA1+3 in the two species and compared their growth responses to the changes of endogenous and exogenous GA3 by using short-term and long-term hydroponics experiments. After a period of homogeneous cultivation, levels of endogenous GA1+3 were higher in W. trilobata than in W. chinensis. The reduction of endogenous GAs repressed the emergence of adventitious roots and the growth of W. trilobata in the initial cultivation stage, and inhibited its shoot elongation and biomass. Levels of endogenous GA1+3 were positively correlated with the length of shoots and adventitious roots of W. trilobata. Adventitious roots of W. trilobata also emerged earlier and grew faster when treated with exogenous GA3. In contrast, exogenous GA3 treatment inhibited the length of adventitious roots in W. chinensis, and levels of endogenous GA1+3 did not correlate with shoot or adventitious root length. Our study suggests that GAs accelerate the rapid clonal growth of W. trilobata, more than that of its native congener W. chinensis, illustrating the relationship between plant hormones and the clonal growth of invasive plants. These findings are important for understanding the mechanisms associated with the invasiveness of clonal plants and their potential management.


Asunto(s)
Giberelinas/fisiología , Especies Introducidas , Wedelia/fisiología , Raíces de Plantas/crecimiento & desarrollo , Wedelia/crecimiento & desarrollo
17.
J Phys Chem Lett ; 15(7): 2096-2104, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38358755

RESUMEN

Excitonic effects caused by the Coulomb interaction between electrons and holes play a crucial role in photocatalysis at the molecule/metal oxide interface. As an ideal model for investigating the excitonic effect, coadsorption and photodissociation of water and methanol molecules on titanium dioxide involve complex ground-state thermalcatalytic and excited-state photocatalytic reaction processes. Herein, we systemically investigate the excited-state electronic structures of the coadsorption of H2O and CH3OH molecules on a rutile TiO2(110) surface by linear-response time-dependent density functional theory calculations and probe the reaction path for generating HCOOH or CO2, from ground-state and excited-state perspectives. The reaction barriers in excited-state calculations are significantly different from those in ground-state calculations during three processes, with the largest decrease being 0.94 eV for the Ti5c-O-CH2-O-Ti5c formation process.

18.
Front Plant Sci ; 15: 1391042, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38988634

RESUMEN

Introduction: Blumea balsamifera L. (Ainaxiang) DC. is a perennial herb of the compositae family. It is also the primary source of natural borneol. Endo-borneol, the principal medical active element in B. balsamifera, is anti-inflammatory, antioxidant, and analgesic; enhances medicine absorption; refreshes; and is used as a spice and in cosmetic. Industrialization of B. balsamifera is limited by its low L-borneol concentration. Thus, understanding the accumulation pattern of the secondary metabolite endo-borneol and its synthesis process in secondary metabolism is critical for increasing B. balsamifera active ingredient content and cultivation efficiency. Methods: In this work, B. balsamifera was treated with varying concentrations (1.00 and 10.00 mmol/L) of methyl jasmonate (MeJA) as an exogenous foliar activator. The physiological parameters and L-borneol concentration were then assessed. Transcriptome sequencing of B. balsamifera-induced leaves was used to identify key genes for monoterpene synthesis. Results: The treatment effect of 1 mmol/L MeJA was the best, and the leaves of all three leaf positions accumulated the highest L-borneol after 120 h, correspondingly 3.043 mg·g-1 FW, 3.346 mg·g-1 FW, and 2.044 mg·g-1 FW, with significant differences from the control. The main assembly produced 509,285 transcripts with min and max lengths of 201 and 23,172, respectively. DEG analysis employing volcano blots revealed 593, 224, 612, 2,405, 1,353, and 921 upregulated genes and 4, 123, 573, 1,745, 766, and 763 downregulated genes in the treatments D1_1vsCK, D1_10vsCK, D2_1vsCK, D2_10vsCK, D5_1vsCK, and D5_10vsCK. Interestingly, when exposed to MeJA treatments, the MEP pathway's unigenes express themselves more than those of the MVA route. Finally, when treated with 1 mmol/L, the genes DXR, DXS, and GPS showed increased expression over time. At the same time, a 10 mmol/L therapy resulted in elevated levels of ispH and GGPS. Discussion: Our preliminary research indicates that exogenous phytohormones can raise the level of L borneol in B. balsamifera (L.) DC when given in the appropriate amounts. The most significant discovery made while analyzing the effects of different hormones and concentrations on B. balsamifera (L.) DC was the effect of 1 mmol/L MeJA treatment.

19.
Nat Commun ; 15(1): 2969, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582766

RESUMEN

Artificial electronic kagome lattices may emerge from electronic potential landscapes using customized structures with exotic supersymmetries, benefiting from the confinement of Shockley surface-state electrons on coinage metals, which offers a flexible approach to realizing intriguing quantum phases of matter that are highly desired but scarce in available kagome materials. Here, we devise a general strategy to construct varieties of electronic kagome lattices by utilizing the on-surface synthesis of halogen hydrogen-bonded organic frameworks (XHOFs). As a proof of concept, we demonstrate three XHOFs on Ag(111) and Au(111) surfaces, which correspondingly deliver regular, breathing, and chiral breathing diatomic-kagome lattices with patterned potential landscapes, showing evident topological edge states at the interfaces. The combination of scanning tunnelling microscopy and noncontact atomic force microscopy, complemented by density functional theory and tight-binding calculations, directly substantiates our method as a reliable and effective way to achieve electronic kagome lattices for engineering quantum states.

20.
PeerJ ; 11: e15164, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37101792

RESUMEN

Background: Metabolism shifts from glycolysis to mitochondrial oxidative phosphorylation are vital during the differentiation of stem cells. Mitochondria have a direct function in differentiation. However, the metabolic shift and the effect of mitochondria in regulating the osteogenic differentiation of human dental pulp stem cells (hDPSCs) remain unclear. Methods: Human dental pulp stem cells were collected from five healthy donors. Osteogenic differentiation was induced by osteogenic induction medium. The activities of alkaline phosphatase, hexokinase, pyruvate kinase, and lactate dehydrogenase were analyzed by enzymatic activity kits. The extracellular acidification rate and the mitochondrial oxygen consumption rate were measured. The mRNA levels of COL-1, ALP, TFAM, and NRF1 were analyzed. The protein levels of p-AMPK and AMPK were detected by western blotting. Results: Glycolysis decreased after a slight increase, while mitochondrial oxidative phosphorylation continued to increase when cells grew in osteogenic induction medium. Therefore, the metabolism of differentiating cells switched to mitochondrial respiration. Next, inhibiting mitochondrial respiration with carbonyl cyanide-chlorophenylhydrazone, a mitochondrial uncoupler inhibited hDPSCs differentiation with less ALP activity and decreased ALP and COL-1 mRNA expression. Furthermore, mitochondrial uncoupling led to AMPK activation. 5-Aminoimidazole-4-carboxamide ribonucleotide, an AMPK activator, simulated the effect of mitochondrial uncoupling by inhibiting osteogenic differentiation, mitochondrial biogenesis, and mitochondrial morphology. Mitochondrial uncoupling and activation of AMPK depressed mitochondrial oxidative phosphorylation and inhibited differentiation, suggesting that they may serve as regulators to halt osteogenic differentiation from impaired mitochondrial oxidative phosphorylation.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Osteogénesis , Humanos , Proteínas Quinasas Activadas por AMP/genética , Pulpa Dental/metabolismo , Células Cultivadas , Diferenciación Celular/fisiología , Mitocondrias/metabolismo , Células Madre , Respiración
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