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1.
J Exp Bot ; 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39082682

RESUMEN

The optimal timing of the transition from vegetative growth to reproductive growth is critical for plant reproductive success, and the underlying regulatory mechanisms have been well studied in angiosperm model species, but relatively little in gymnosperms. DAL1, a MADS domain transcription factor (TF) gene that shows a conserved age-related expression profile in conifers, may be an age timer. However, how the DAL1 mediates the onset of reproductive growth remains poorly understood. Here, we have shown that the PtDAL1 directly regulates the PtDAL10 transcription by binding to its promoter region in vitro. PtDAL1, forms ternary complexes in vitro and in N. benthamiana with PtDAL10 and PtMADS11, two potential candidate regulators of the vegetative to reproductive transition in Chinese pine (Pinus tabuliformis). The PtDAL10 was progressively induced in new shoots with age and highly accumulated in male and female cones. Overexpression of PtDAL10 rescued the flowering of ft-10 and soc1-1-2 mutants in Arabidopsis. We provide insight into the molecular components associated with the PtDAL1, which integrates the vegetative to reproductive phase transition into age-mediated progressive development of the whole plant in conifers.

2.
J Health Psychol ; : 13591053241245100, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38600686

RESUMEN

Social media platforms play a significant role in the lives of young people. While the usage of these platforms has grown, research exploring the challenges of body image remains limited. This study investigated whether initiating negative body talk functioned as an indirect pathway between appearance comparison on social media and body shame and whether perceived sociocultural influences from parents, friends, and media on body image moderated this indirect effect. An online cross-sectional survey of 795 Chinese college students (Mage = 20.17, SD = 1.65; 60% female, 40% male) was conducted. Negative body talk was a partial indirect pathway in the association, and this indirect effect was significant among those experiencing higher sociocultural pressures from all three sources. This study highlights the need for health psychology in understanding and addressing the mental health consequences associated with digital media and sociocultural influences on body image perception.

3.
Soft Robot ; 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38386561

RESUMEN

Soft robotics promises to achieve safe and efficient interactions with the environment by exploiting its inherent compliance and designing control strategies. However, effective control for the soft robot-environment interaction has been a challenging task. The challenges arise from the nonlinearity and complexity of soft robot dynamics, especially in situations where the environment is unknown and uncertainties exist, making it difficult to establish analytical models. In this study, we propose a learning-based optimal control approach as an attempt to address these challenges, which is an optimized combination of a feedforward controller based on probabilistic model predictive control and a feedback controller based on nonparametric learning methods. The approach is purely data-driven, without prior knowledge of soft robot dynamics and environment structures, and can be easily updated online to adapt to unknown environments. A theoretical analysis of the approach is provided to ensure its stability and convergence. The proposed approach enabled a soft robotic manipulator to track target positions and forces when interacting with a manikin in different cases. Moreover, comparisons with other data-driven control methods show a better performance of our approach. Overall, this work provides a viable learning-based control approach for soft robot-environment interactions with force/position tracking capability.

4.
Front Oncol ; 14: 1406764, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39055565

RESUMEN

Background: Hepatocellular carcinoma (HCC) patients with compensated cirrhosis typically face a high prevalence and unfavorable prognosis. However, there is currently a deficiency in prediction models to anticipate the prognosis of these patients. Therefore, our study included the Gamma-glutamyl transpeptidase-to-platelet ratio (GPR) in analysis and aimed to develop a nomogram for HCC patients with compensated cirrhosis after local ablation. Methods: Enrolling 669 patients who underwent local ablation at Beijing You'an Hospital during the period from January 1, 2014, to December 31, 2022, this study focused on individuals with compensated cirrhotic HCC. In a ratio of 7:3, patients were allocated to the training cohort (n=468) and the validation cohort (n=201). Lasso-Cox regression was employed to identify independent prognostic factors for overall survival (OS). Subsequently, a nomogram was constructed using these factors and was validated through receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Results: GPR, age, and hemoglobin were identified by Lasso-Cox regression as independent prognostic factors of the nomogram. The area under the ROC curves (AUCs) for 3-, 5-, and 8-year OS (0.701, 0.755, and 0.768 for the training cohort; 0.684, 0.707, and 0.778 for the validation cohort), and C-indices (0.695 for training cohort; 0.679 for validation cohort) exhibited the excellent predictive ability of the nomogram. Calibration curves and DCA curves indicated favorable calibration performance and clinical utility. Patients were further stratified into two risk groups according to the median nomogram score. There existed an obvious distinction between the two groups both in the training cohort and validation cohort. Conclusion: In summary, this research established and validated a novel nomogram to predict OS, which had good predictive power for HCC patients with compensated cirrhosis after local ablation.

5.
Biomolecules ; 14(4)2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38672469

RESUMEN

Porcine extraintestinal pathogenic Escherichia coli (ExPEC) is a pathogenic bacterium that causes huge economic losses to the pig farming industry and considerably threatens human health. The quorum sensing (QS) system plays a crucial role in the survival and pathogenesis of pathogenic bacteria. Hence, it is a viable approach to prevent ExPEC infection by compromising the QS system, particularly the LuxS/AI-2 system. In this study, we investigated the effects of baicalin on the LuxS/AI-2 system of ExPEC. Baicalin at concentrations of 25, 50, and 100 µg/mL significantly diminished the survival ability of ExPEC in hostile environments and could inhibit the biofilm formation and autoagglutination ability in ExPEC. Moreover, baicalin dose-dependently decreased the production of AI-2 and down-regulated the expression level of luxS in PCN033. These results suggest that baicalin can weaken the virulence of PCN033 by inhibiting the LuxS/AI-2 system. After the gene luxS was deleted, AI-2 production in PCN033 was almost completely eliminated, similar to the effect of baicalin on the production of AI-2 in PCN033. This indicates that baicalin reduced the production of AI-2 by inhibiting the expression level of luxS in ExPEC. In addition, the animal experiment further showed the potential of baicalin as a LuxS/AI-2 system inhibitor to prevent ExPEC infection. This study highlights the potential of baicalin as a natural quorum-sensing inhibitor for therapeutic applications in preventing ExPEC infection by targeting the LuxS/AI-2 system.


Asunto(s)
Proteínas Bacterianas , Liasas de Carbono-Azufre , Escherichia coli Patógena Extraintestinal , Flavonoides , Homoserina , Homoserina/análogos & derivados , Percepción de Quorum , Percepción de Quorum/efectos de los fármacos , Flavonoides/farmacología , Animales , Liasas de Carbono-Azufre/genética , Liasas de Carbono-Azufre/metabolismo , Porcinos , Virulencia/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Homoserina/metabolismo , Escherichia coli Patógena Extraintestinal/efectos de los fármacos , Escherichia coli Patógena Extraintestinal/patogenicidad , Escherichia coli Patógena Extraintestinal/genética , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Lactonas/farmacología , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/tratamiento farmacológico
6.
Sci Adv ; 10(8): eadk7140, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38394197

RESUMEN

Acaryochloris marina is a unique cyanobacterium using chlorophyll d (Chl d) as its major pigment and thus can use far-red light for photosynthesis. Photosystem II (PSII) of A. marina associates with a number of prochlorophyte Chl-binding (Pcb) proteins to act as the light-harvesting system. We report here the cryo-electron microscopic structure of a PSII-Pcb megacomplex from A. marina at a 3.6-angstrom overall resolution and a 3.3-angstrom local resolution. The megacomplex is organized as a tetramer consisting of two PSII core dimers flanked by sixteen symmetrically related Pcb proteins, with a total molecular weight of 1.9 megadaltons. The structure reveals the detailed organization of PSII core consisting of 15 known protein subunits and an unknown subunit, the assembly of 4 Pcb antennas within each PSII monomer, and possible pathways of energy transfer within the megacomplex, providing deep insights into energy transfer and dissipation mechanisms within the PSII-Pcb megacomplex involved in far-red light utilization.


Asunto(s)
Complejo de Proteína del Fotosistema II , Proclorofitas , Complejo de Proteína del Fotosistema II/metabolismo , Clorofila/metabolismo , Fotosíntesis
7.
Front Microbiol ; 15: 1367658, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38737410

RESUMEN

Introduction: Nitrososphaeria, formerly known as Thaumarchaeota, constitute a diverse and widespread group of ammonia-oxidizing archaea (AOA) inhabiting ubiquitously in marine and terrestrial environments, playing a pivotal role in global nitrogen cycling. Despite their importance in Earth's ecosystems, the cellular organization of AOA remains largely unexplored, leading to a significant unanswered question of how the machinery of these organisms underpins metabolic functions. Methods: In this study, we combined spherical-chromatic-aberration-corrected cryo-electron tomography (cryo-ET), scanning transmission electron microscopy (STEM), and energy dispersive X-ray spectroscopy (EDS) to unveil the cellular organization and elemental composition of Nitrosopumilus maritimus SCM1, a representative member of marine Nitrososphaeria. Results and Discussion: Our tomograms show the native ultrastructural morphology of SCM1 and one to several dense storage granules in the cytoplasm. STEM-EDS analysis identifies two types of storage granules: one type is possibly composed of polyphosphate and the other polyhydroxyalkanoate. With precise measurements using cryo-ET, we observed low quantity and density of ribosomes in SCM1 cells, which are in alignment with the documented slow growth of AOA in laboratory cultures. Collectively, these findings provide visual evidence supporting the resilience of AOA in the vast oligotrophic marine environment.

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