Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 346
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-39312936

RESUMO

In the study of strongly correlated electrons, one of the challenging core tasks is to develop the potential techniques for direct detection of the many-body correlations of strongly correlated electrons. The (γ, 2e) photoemission technique has been developed to investigate the two-body correlations of the target correlated electrons. In this article, we will focus on this technique for the correlated electrons near the Fermi energy in condensed matter. The coincidence detection probability of the two emitted electrons in the (γ, 2e) photoemission measurement is shown to be relevant to a two-body Bethe-Salpeter wave function, which describes the dynamical two-body correlations of the target correlated electrons near the Fermi energy. As the coincidence detection probability involves an electron-electron interaction matrix element, the arbitrary momentum and/or energy transfer due to this electron-electron interaction makes the (γ, 2e) photoemission technique fail to reveal the inner-pair structures of the two-body Bethe-Salpeter wave function. However, the center-of-mass momentum and energy of the two-body Bethe-Salpeter wave function can be distinctly resolved. Thus, the (γ, 2e) photoemission technique can provide the center-of-mass physics of the two-body correlations of the target correlated electrons. It will be one potential technique to study the center-of-mass physics of the Cooper pairs in superconductor.

2.
Int J Mol Sci ; 25(17)2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39273154

RESUMO

UV-B stress destroys the photosynthetic system of Rhododendron chrysanthum Pall. (R. chrysanthum), as manifested by the decrease of photosynthetic efficiency and membrane fluidity, and also promotes the accumulation of lignin. The MYB (v-myb avian myeloblastosis viral oncogene homolog) family of transcription factors can be involved in the response to UV-B stress through the regulation of lignin biosynthesis. This study indicated that both the donor and recipient sides of the R. chrysanthum were significantly damaged based on physiological index measurements made using OJIP curves under UV-B stress. The analysis of bioinformatics data revealed that the RcTRP5 transcription factor exhibits upregulation of acetylation at the K68 site, directly regulating the biosynthesis of lignin. Additionally, there was upregulation of the K43 site and downregulation of the K83 site of the CAD enzyme, as well as upregulation of the K391 site of the PAL enzyme. Based on these findings, we conjectured that the RcTRP5 transcription factor facilitates acetylation modification of both enzymes, thereby indirectly influencing the biosynthesis of lignin. This study demonstrated that lignin accumulation can alleviate the damage caused by UV-B stress to R. chrysanthum, which provides relevant ideas for improving lignin content in plants, and also provides a reference for the study of the metabolic regulation mechanism of other secondary substances.


Assuntos
Regulação da Expressão Gênica de Plantas , Lignina , Proteínas de Plantas , Fatores de Transcrição , Raios Ultravioleta , Lignina/biossíntese , Lignina/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Acetilação
3.
Plant Divers ; 46(4): 530-536, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39280971

RESUMO

Forests, the largest terrestrial carbon sinks, play an important role in carbon sequestration and climate change mitigation. Although forest attributes and environmental factors have been shown to impact aboveground biomass, their influence on biomass stocks in species-rich forests in southern China, a biodiversity hotspot, has rarely been investigated. In this study, we characterized the effects of environmental factors, forest structure, and species diversity on aboveground biomass stocks of 30 plots (1 ha each) in natural forests located within seven nature reserves distributed across subtropical and marginal tropical zones in Guangxi, China. Our results indicate that forest aboveground biomass stocks in this region are lower than those in mature tropical and subtropical forests in other regions. Furthermore, we found that aboveground biomass was positively correlated with stand age, mean annual precipitation, elevation, structural attributes and species richness, although not with species evenness. When we compared stands with the same basal area, we found that aboveground biomass stock was higher in communities with a higher coefficient of variation of diameter at breast height. These findings highlight the importance of maintaining forest structural diversity and species richness to promote aboveground biomass accumulation and reveal the potential impacts of precipitation changes resulting from climate warming on the ecosystem services of subtropical and northern tropical forests in China. Notably, many natural forests in southern China are not fully stocked. Therefore, their continued growth will increase their carbon storage over time.

4.
Oncol Lett ; 28(5): 532, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39290960

RESUMO

Malignant melanoma meningeal metastasis (MMMM) is a rare clinical condition with a poor prognosis. The observation of hemorrhagic cerebrospinal fluid (CSF) in this type of disease is relatively uncommon and may indicate disease progression. The present study reports the case of a 51-year-old male with malignant melanoma who presented with a headache. Imaging studies did not identify abnormalities; however, an analysis of the CSF revealed hemorrhagic changes. The results of cytological examination of the CSF showed melanoma cells, leading to the final diagnosis of MMMM. This case emphasizes the importance of monitoring neurological symptoms and conducting comprehensive CSF cytological examination in patients with melanoma, creating disease awareness in clinicians.

5.
EBioMedicine ; 107: 105311, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39191174

RESUMO

BACKGROUND: The accurate evaluation of axillary lymph node (ALN) response to neoadjuvant chemotherapy (NAC) in breast cancer holds great value. This study aimed to develop an artificial intelligence system utilising multiregional dynamic contrast-enhanced MRI (DCE-MRI) and clinicopathological characteristics to predict axillary pathological complete response (pCR) after NAC in breast cancer. METHODS: This study included retrospective and prospective datasets from six medical centres in China between May 2018 and December 2023. A fully automated integrated system based on deep learning (FAIS-DL) was built to perform tumour and ALN segmentation and axillary pCR prediction sequentially. The predictive performance of FAIS-DL was assessed using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity. RNA sequencing analysis were conducted on 45 patients to explore the biological basis of FAIS-DL. FINDINGS: 1145 patients (mean age, 50 years ±10 [SD]) were evaluated. Among these patients, 506 were in the training and validation sets (axillary pCR rate of 40.3%), 127 in the internal test set (axillary pCR rate of 37.8%), 414 in the pooled external test set (axillary pCR rate of 48.8%), and 98 in the prospective test set (axillary pCR rate of 43.9%). For predicting axillary pCR, FAIS-DL achieved AUCs of 0.95, 0.93, and 0.94 in the internal test set, pooled external test set, and prospective test set, respectively, which were also significantly higher than those of the clinical model and deep learning models based on single-regional DCE-MRI (all P < 0.05, DeLong test). In the pooled external and prospective test sets, the FAIS-DL decreased the unnecessary axillary lymph node dissection rate from 47.9% to 6.8%, and increased the benefit rate from 52.2% to 86.5%. RNA sequencing analysis revealed that high FAIS-DL scores were associated with the upregulation of immune-mediated genes and pathways. INTERPRETATION: FAIS-DL has demonstrated satisfactory performance in predicting axillary pCR, which may guide the formulation of personalised treatment regimens for patients with breast cancer in clinical practice. FUNDING: This study was supported by the National Natural Science Foundation of China (82371933), National Natural Science Foundation of Shandong Province of China (ZR2021MH120), Mount Taishan Scholars and Young Experts Program (tsqn202211378), Key Projects of China Medicine Education Association (2022KTM030), China Postdoctoral Science Foundation (314730), and Beijing Postdoctoral Research Foundation (2023-zz-012).


Assuntos
Neoplasias da Mama , Linfonodos , Imageamento por Ressonância Magnética , Terapia Neoadjuvante , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Feminino , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos , Linfonodos/patologia , Linfonodos/diagnóstico por imagem , Axila , Adulto , Curva ROC , Meios de Contraste , Aprendizado Profundo , Metástase Linfática , Resultado do Tratamento , Estudos Retrospectivos , Estudos Prospectivos , Prognóstico
6.
Plant Cell Rep ; 43(9): 224, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39215829

RESUMO

KEY MESSAGE: This study, using multi-omics combined with physiologic assays, found that calcium-ion signaling can regulate phenolic acid accumulation in R. chrysanthum leaves in response to UV-B stress. UV-B stress is a severe abiotic stress capable of destroying cellular structures and affecting plant growth. Rhododendron chrysanthum Pall. (R. chrysanthum) is a plant that has been exposed to high levels of UV-B radiation for an extended period, leading to the development of adaptive responses to mitigate UV-B stress. As such, it serves as a valuable experimental material for studying plant resilience to UV-B stress. We utilized R. chrysanthum as the experimental material and subjected it to UV-B stress. We conducted a comprehensive analysis of the changes in R. chrysanthum under both control and UV-B stress conditions using multi-omic and physiologic assays. Our aim was to investigate the molecular mechanism underlying R. chrysanthum's resistance to UV-B stress, with a focus on calcium-ion signaling. UV-B stress was found to impact the photosynthesis of R. chrysanthum by decreasing the maximum photosynthetic efficiency of photosystem II, reducing Fm, and increasing F0. In addition, the composition of numerous phenolic acid compounds was significantly altered. Genes and proteins related to calcium signaling showed significant differences, with some proteins (CML, CPK1, CRK3, ATP2C, ERG3, CAR7) being modified by acetylation. The correlation between genes and proteins involved in calcium signaling and phenolic compounds suggested that calcium signaling may play a role in regulating the accumulation of phenolic compounds under UV-B stress to help R. chrysanthum adapt. This study examines the impact of calcium-ion signaling on the accumulation of phenolic acid compounds, offering insights for future research on the molecular mechanisms underlying plant resilience to UV-B stress.


Assuntos
Sinalização do Cálcio , Hidroxibenzoatos , Rhododendron , Estresse Fisiológico , Raios Ultravioleta , Hidroxibenzoatos/metabolismo , Sinalização do Cálcio/efeitos da radiação , Rhododendron/metabolismo , Rhododendron/efeitos da radiação , Rhododendron/genética , Rhododendron/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Fotossíntese/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
7.
Sci Bull (Beijing) ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39174404

RESUMO

After several decades of studies of high-temperature superconductivity, there is no compelling theory for the mechanism yet; however, the spin fluctuations have been widely believed to play a crucial role in forming the superconducting Cooper pairs. The recent discovery of high-temperature superconductivity near 80 K in the bilayer nickelate La3Ni2O7 under pressure provides a new platform to elucidate the origins of high-temperature superconductivity. We perform elastic and inelastic neutron scattering studies on a polycrystalline sample of La3Ni2O7-δ at ambient pressure. No magnetic order can be identified down to 10 K. The absence of long-range magnetic order in neutron diffraction measurements may be ascribed to the smallness of the magnetic moment. However, we observe a weak flat spin-fluctuation signal in the inelastic scattering spectra at ∼ 45 meV. The observed spin excitations could be interpreted as a result of strong interlayer and weak intralayer magnetic couplings for stripe-type antiferromagnetic orders. Our results provide crucial information on the spin dynamics and are thus important for understanding the superconductivity in La3Ni2O7.

8.
Small ; : e2403486, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-39031678

RESUMO

The development of high-performance organic photovoltaic materials is of crucial importance for the commercialization of organic solar cells (OSCs). Herein, two structurally simple donor-π-conjugated linker-acceptor (D-π-A)-configured small-molecule donors with methyl-substituted triphenylamine as D unit, 1,1-dicyanomethylene-3-indanone as A unit, and thiophene or furan as π-conjugated linker, named DTICPT and DTICPF, are developed. DTICPT and DTICPF are facilely prepared via a two-step synthetic process with simple procedures. DTICPF with a furan π-conjugated linker exhibits stronger and broader optical absorption, deeper highest occupied molecular orbital (HOMO) energy levels, and better charge transport, compared to its thiophene analog DTICPT. As a result, vacuum-deposited OSCs based on DTICPF: C70 show an impressive power conversion efficiency (PCE) of 9.36% (certified 9.15%) with short-circuit current density (Jsc) up to 17.49 mA cm-2 (certified 17.56 mA cm-2), which is the highest Jsc reported so far for vacuum-deposited OSCs. Besides, devices based on DTICPT: C70 and DTICPF: C70 exhibit excellent long-term stability under different aging conditions. This work offers important insights into the rational design of D-π-A configured small-molecule donors for high efficient and stable vacuum-deposited OSCs.

9.
Nanotechnology ; 35(41)2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39025081

RESUMO

Flexible electronics, such as wearable displays, implantable electronics, soft robots, and smart skin, have garnered increasing attention. Despite notable advancements in research, a bottleneck remains at the product level due to the prevalent use of polymer-based materials, requiring encapsulation films for lifespan extension and reliable performance. Multilayer composites, incorporating thin inorganic layers to maintain low permeability towards moisture, oxygen, ions, etc, exhibit potential in achieving highly flexible barriers but encounter challenges stemming from interface instability between layers. This perspective offers a succinct review of strategies and provides atomic-scale interface modulation strategy utilizing atomic layer integration technology focused on enhancing the flexibility of high-barrier films. It delves into bendable multilayers with atomic-scale interface modulation strategies, encompassing internal stress and applied stress modulation, as well as stretchable composite structural designs such as gradient/hybrid, wavy, and island. These strategies showcase significant improvements in flexibility from bendable to stretchable while maintaining high barrier properties. Besides, optimized manufacturing methods, materials, and complex structure design based on atomic-scale interface engineering are provided, better aligning with the future development of flexible electronics. By laying the groundwork for these atomic-scale strategies, this perspective contributes to the evolution of flexible electronics, enhancing their flexibility, durability, and functionality.

10.
ACS Nano ; 18(23): 15055-15066, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38825792

RESUMO

The stability issue of Sn-based perovskite solar cells (PSCs) is expected to be resolved by involving a two-dimensional (2D) layered structure. However, Sn-based 2D PSCs, especially Dion-Jacobson (DJ)-phase ones with potentially good stability, have rarely been reported. Herein, superior DJ-phase Sn 2D perovskites with 3-aminobenzylamine (3ABA2+) or 4-aminobenzylamine (4ABA2+) π-conjugated short-chain ligands are reported to fabricate efficient 2D lead-free PSCs. Notably, the high dipole moment of the 3ABAI2 organic spacer is approved to possess faster charge transfer for forming (3ABA)FA4Sn5I16 2D perovskite with an extremely low exciton binding energy (only 84 meV). In combination with a diacetate partial substitution and methylamine iodide/bromide (MAI/MABr) post-treatment strategy to delay crystallization and improve compactness and coverage of the perovskite film, a record power conversion efficiency (PCE) of 6.81% and stability of 840 h (less than 5% degradation in a N2 atmosphere for unencapsulated devices) are acquired in eventual (3ABA)FA4Sn5I16 2D PSCs, which are among the highest PCE and the longest stability of Sn-based 2D PSCs reported to date. Our work provides a prospective molecule design and film preparation strategy of 2D Sn perovskites toward nontoxic high-performance tin-based PSCs, which pushes the almost stagnant research forward.

11.
Biodivers Data J ; 12: e127120, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38912114

RESUMO

Background: Wuzhizhou Island (WZZ) is located in Haitang Bay in the northern region of Sanya, Hainan Island. The sea area surrounding WZZ represents a typical tropical marine ecosystem, characterised by diverse and complex habitats. Therefore, there is a rich variety of marine fish species at WZZ. The marine ecosystem of WZZ was seriously destroyed initially in the 1970s-1980s and recovered in the 1990s, then constructed as the first national tropical marine ranch demonstration area of China in 2019. As fish is an important high trophic vertebrate in the marine ecosystem, understanding the composition and distribution of fish species could help us to recognise the status of the ecosystem of WZZ and supply scientific data for construction of the national marine ranch demonstration area. This study used eDNA technology to investigate the composition of fish community surrounding WZZ and provided a scientific basis for realising and protecting the marine ecosystem of the South China Sea. New information: The WZZ is an offshore island in the South China Sea, harbouring abundant marine fish resources. Although previous research investigated fish species of WZZ, the data were, however, still incomplete due to limitation of sampling methods and survey seasons. In this study, we intended to take advantage of eDNA and supplement data of fish species at WZZ as much as possible. Based on eDNA, this study provided the data on 188 fish species (including nine undetermined species denoted by genus sp.) belonging to 17 orders, 63 families and 124 genera and they were the more comprehensive records of fish species surrounding WZZ. In addition, the information on Molecular Operational Taxonomic Units (MOTUs) for taxon identification was also provided, aiming to contribute to the establishment of a specific eDNA taxon database for fish of the South China Sea. This study included two datasets, which were occurrences of fish taxa at WZZ, as well as MOTUs sequences and geographical coordinate information of sampling sites. The "fish taxon occurrences" dataset presented records on taxonomic, distribution and habitat conditions of 188 fish species detected using eDNA, as well as the latitude and longitude information of the sampling sites, the "MOTUs information" dataset provided the MOTUs sequences, source of sequences, abundance of sequences for 188 fish species, also included the species matched in NCBI and the best NCBI BLAST sequence similarity.

12.
ACS Appl Mater Interfaces ; 16(25): 32240-32248, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38877977

RESUMO

Sn-based perovskite solar cells (Sn-PSCs) have received increasing attention due to their nontoxicity and potentially high efficiency. However, the poor stability of Sn2+ ions remains a major problem in achieving stable and efficient Sn-PSCs. Herein, an in situ polymerization strategy using allyl thiourea and ethylene glycol dimethacrylate as cross-linking agents in the Sn-based perovskite precursor is proposed to improve the device performance of Sn-PSCs. The C═S and N-H bonds of the cross-linkers are able to coordinate with SnI2 and inhibit the oxidation of Sn2+, thereby reducing defect density and improving the stability of Sn-based perovskite films. The high quality of the perovskite film induced by the in situ polymerization strategy delivers an improved power conversion efficiency (PCE) from 7.50 to 9.22%. More importantly, the unpackaged device with cross-linkers maintained more than 70% of the initial PCE after 150 h of AM 1.5G light soaking in a nitrogen atmosphere and 80% of the initial PCE after 1800 h in dark conditions. This work demonstrates that the in situ polymerization strategy is an effective method to enhance the stability of Sn-based perovskite films and devices.

13.
Phys Chem Chem Phys ; 26(26): 18196-18204, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38904087

RESUMO

The Zr-2.5Nb alloy is a typical pressure tube material in heavy water nuclear reactors, and an increase of hydrogen isotope content in the alloy during service can pose major safety risks; hot vacuum extraction-mass spectrometry is an efficient method for evaluating hydrogen isotope concentrations in the Zr-2.5Nb alloy. This work investigates the kinetics and thermodynamic properties of deuterium (D) absorption and desorption of the Zr-2.5Nb alloy using the constant volume adsorption method and the hot vacuum extraction method. In addition to the previously reported volume contraction model, it was observed that at 600 °C and above, the reaction between D2 and Zr-2.5Nb is dominated by diffusion, while the reaction is predominantly influenced by surface adsorption and dissociation below 600 °C. Phase transition sequence of Zr-2.5Nb deuterides during non-isothermal desorption was established using quantitatively calibrated thermal desorption spectra combined with the phase transition process of deuteride decomposition. These results can provide important references for optimizing the process parameters of the hot vacuum extraction-mass spectrometry method.

14.
Biomolecules ; 14(6)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38927135

RESUMO

Lysine acetylation of proteins plays a critical regulatory function in plants. A few advances have been made in the study of plant acetylproteome. However, until now, there have been few data on Rhododendron chrysanthum Pall. (R. chrysanthum). We analyzed the molecular mechanisms of photosynthesis and stress resistance in R. chrysanthum under UV-B stress. We measured chlorophyll fluorescence parameters of R. chrysanthum under UV-B stress and performed a multi-omics analysis. Based on the determination of chlorophyll fluorescence parameters, R. chrysanthum Y(NO) (Quantum yield of non-photochemical quenching) increased under UV-B stress, indicating that the plant was damaged and photosynthesis decreased. In the analysis of acetylated proteomics data, acetylated proteins were found to be involved in a variety of biological processes. Notably, acetylated proteins were significantly enriched in the pathways of photosynthesis and carbon fixation, suggesting that lysine acetylation modifications have an important role in these activities. Our findings suggest that R. chrysanthum has decreased photosynthesis and impaired photosystems under UV-B stress, but NPQ shows that plants are resistant to UV-B. Acetylation proteomics revealed that up- or down-regulation of acetylation modification levels alters protein expression. Acetylation modification of key enzymes of the Calvin cycle (Rubisco, GAPDH) regulates protein expression, making Rubisco and GAPDH proteins expressed as significantly different proteins, which in turn affects the carbon fixation capacity of R. chrysanthum. Thus, Rubisco and GAPDH are significantly differentially expressed after acetylation modification, which affects the carbon fixation capacity and thus makes the plant resistant to UV-B stress. Lysine acetylation modification affects biological processes by regulating the expression of key enzymes in photosynthesis and carbon fixation, making plants resistant to UV-B stress.


Assuntos
Ciclo do Carbono , Fotossíntese , Rhododendron , Ribulose-Bifosfato Carboxilase , Raios Ultravioleta , Acetilação , Rhododendron/metabolismo , Rhododendron/genética , Ribulose-Bifosfato Carboxilase/metabolismo , Estresse Fisiológico , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Proteômica , Regulação da Expressão Gênica de Plantas , Clorofila/metabolismo , Lisina/metabolismo
15.
New Phytol ; 243(3): 881-893, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38840520

RESUMO

Differences in demographic and environmental niches facilitate plant species coexistence in tropical forests. However, the adaptations that enable species to achieve higher demographic rates (e.g. growth or survival) or occupy unique environmental niches (e.g. waterlogged conditions) remain poorly understood. Anatomical traits may better predict plant environmental and demographic strategies because they are direct measurements of structures involved in these adaptations. We collected 18 leaf and twig traits from 29 tree species in a tropical freshwater swamp forest in Singapore. We estimated demographic parameters of the 29 species from growth and survival models, and degree of association toward swamp habitats. We examined pairwise trait-trait, trait-demography and trait-environment links while controlling for phylogeny. Leaf and twig anatomical traits were better predictors of all demographic parameters than other commonly measured leaf and wood traits. Plants with wider vessels had faster growth rates but lower survival rates. Leaf and spongy mesophyll thickness predicted swamp association. These findings demonstrate the utility of anatomical traits as indicators of plant hydraulic strategies and their links to growth-mortality trade-offs and waterlogging stress tolerance that underlie species coexistence mechanisms in tropical forest trees.


Assuntos
Adaptação Fisiológica , Florestas , Folhas de Planta , Árvores , Clima Tropical , Áreas Alagadas , Folhas de Planta/fisiologia , Folhas de Planta/anatomia & histologia , Árvores/fisiologia , Característica Quantitativa Herdável , Água Doce , Ecossistema , Especificidade da Espécie
16.
Plant Divers ; 46(3): 395-405, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38798723

RESUMO

Stomatal regulation is critical for mangroves to survive in the hyper-saline intertidal zone where water stress is severe and water availability is highly fluctuant. However, very little is known about the stomatal sensitivity to vapour pressure deficit (VPD) in mangroves, and its co-ordination with stomatal morphology and leaf hydraulic traits. We measured the stomatal response to a step increase in VPD in situ, stomatal anatomy, leaf hydraulic vulnerability and pressure-volume traits in nine true mangrove species of five families and collected the data of genome size. We aimed to answer two questions: (1) Does stomatal morphology influence stomatal dynamics in response to a high VPD in mangroves? with a consideration of possible influence of genome size on stomatal morphology; and (2) do leaf hydraulic traits influence stomatal sensitivity to VPD in mangroves? We found that the stomata of mangrove plants were highly sensitive to a step rise in VPD and the stomatal responses were directly affected by stomatal anatomy and hydraulic traits. Smaller, denser stomata was correlated with faster stomatal closure at high VPD across the species of Rhizophoraceae, and stomata size negatively and vein density positively correlated with genome size. Less negative leaf osmotic pressure at the full turgor (πo) was related to higher operating steady-state stomatal conductance (gs); and a higher leaf capacitance (Cleaf) and more embolism resistant leaf xylem were associated with slower stomatal responses to an increase in VPD. In addition, stomatal responsiveness to VPD was indirectly affected by leaf morphological traits, which were affected by site salinity and consequently leaf water status. Our results demonstrate that mangroves display a unique relationship between genome size, stomatal size and vein packing, and that stomatal responsiveness to VPD is regulated by leaf hydraulic traits and stomatal morphology. Our work provides a quantitative framework to better understand of stomatal regulation in mangroves in an environment with high salinity and dynamic water availability.

17.
Int J Surg ; 110(5): 2593-2603, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38748500

RESUMO

PURPOSE: The authors aimed to establish an artificial intelligence (AI)-based method for preoperative diagnosis of breast lesions from contrast enhanced mammography (CEM) and to explore its biological mechanism. MATERIALS AND METHODS: This retrospective study includes 1430 eligible patients who underwent CEM examination from June 2017 to July 2022 and were divided into a construction set (n=1101), an internal test set (n=196), and a pooled external test set (n=133). The AI model adopted RefineNet as a backbone network, and an attention sub-network, named convolutional block attention module (CBAM), was built upon the backbone for adaptive feature refinement. An XGBoost classifier was used to integrate the refined deep learning features with clinical characteristics to differentiate benign and malignant breast lesions. The authors further retrained the AI model to distinguish in situ and invasive carcinoma among breast cancer candidates. RNA-sequencing data from 12 patients were used to explore the underlying biological basis of the AI prediction. RESULTS: The AI model achieved an area under the curve of 0.932 in diagnosing benign and malignant breast lesions in the pooled external test set, better than the best-performing deep learning model, radiomics model, and radiologists. Moreover, the AI model has also achieved satisfactory results (an area under the curve from 0.788 to 0.824) for the diagnosis of in situ and invasive carcinoma in the test sets. Further, the biological basis exploration revealed that the high-risk group was associated with the pathways such as extracellular matrix organization. CONCLUSIONS: The AI model based on CEM and clinical characteristics had good predictive performance in the diagnosis of breast lesions.


Assuntos
Inteligência Artificial , Neoplasias da Mama , Mamografia , Humanos , Feminino , Mamografia/métodos , Neoplasias da Mama/diagnóstico por imagem , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Meios de Contraste , Idoso , Aprendizado Profundo , Mama/diagnóstico por imagem , Mama/patologia
19.
Glob Chang Biol ; 30(4): e17274, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38605677

RESUMO

Climate change and other anthropogenic disturbances are increasing liana abundance and biomass in many tropical and subtropical forests. While the effects of living lianas on species diversity, ecosystem carbon, and nutrient dynamics are receiving increasing attention, the role of dead lianas in forest ecosystems has been little studied and is poorly understood. Trees and lianas coexist as the major woody components of forests worldwide, but they have very different ecological strategies, with lianas relying on trees for mechanical support. Consequently, trees and lianas have evolved highly divergent stem, leaf, and root traits. Here we show that this trait divergence is likely to persist after death, into the afterlives of these organs, leading to divergent effects on forest biogeochemistry. We introduce a conceptual framework combining horizontal, vertical, and time dimensions for the effects of liana proliferation and liana tissue decomposition on ecosystem carbon and nutrient cycling. We propose a series of empirical studies comparing traits between lianas and trees to answer questions concerning the influence of trait afterlives on the decomposability of liana and tree organs. Such studies will increase our understanding of the contribution of lianas to terrestrial biogeochemical cycling, and help predict the effects of their increasing abundance.


Assuntos
Ecossistema , Clima Tropical , Florestas , Árvores , Carbono
20.
Plant Physiol Biochem ; 210: 108541, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38552264

RESUMO

Heat shock transcription factors (Hsfs) play multifaceted roles in plant growth, development, and responses to environmental factors. However, their involvement in seed dormancy and germination processes has remained elusive. In this study, we identified a wheat class B Hsf gene, TaHsf-7A, with higher expression in strong-dormancy varieties compared to weak-dormancy varieties during seed imbibition. Specifically, TaHsf-7A expression increased during seed dormancy establishment and subsequently declined during dormancy release. Through the identification of a 1-bp insertion (ins)/deletion (del) variation in the coding region of TaHsf-7A among wheat varieties with different dormancy levels, we developed a CAPS marker, Hsf-7A-1319, resulting in two allelic variations: Hsf-7A-1319-ins and Hsf-7A-1319-del. Notably, the allele Hsf-7A-1319-ins correlated with a reduced seed germination rate and elevated dormancy levels, while Hsf-7A-1319-del exhibited the opposite trend across 175 wheat varieties. The association of TaHsf-7A allelic status with seed dormancy and germination levels was confirmed in various genetically modified species, including Arabidopsis, rice, and wheat. Results from the dual luciferase assay demonstrated notable variations in transcriptional activity among transformants harboring distinct TaHsf-7A alleles. Furthermore, the levels of abscisic acid (ABA) and gibberellin (GA), along with the expression levels of ABA and GA biosynthesis genes, showed significant differences between transgenic rice lines carrying different alleles of TaHsf-7A. These findings represent a significant step towards a comprehensive understanding of TaHsf-7A's involvement in the dormancy and germination processes of wheat seeds.


Assuntos
Germinação , Fatores de Transcrição de Choque Térmico , Dormência de Plantas , Proteínas de Plantas , Sementes , Triticum , Alelos , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Germinação/genética , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Dormência de Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Sementes/genética , Sementes/crescimento & desenvolvimento , Triticum/genética , Triticum/metabolismo , Triticum/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA