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1.
Front Plant Sci ; 13: 963269, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36119592

RESUMO

The tea plant is a kind of ammonium-preferring crop, but the mechanism whereby ammonium (NH4 +) regulate its growth is not well understood. The current study focused on the effects of NH4 + on tea plants. Transcriptomic analysis was performed to investigate the early- and late-stage NH4 + deprivation and resupply in tea plants shoots. Through short- and long-term NH4 + deficiency, the dynamic response to NH4 + stress was investigated. The most significant effects of NH4 + deficiency were found to be on photosynthesis and gene ontology (GO) enrichment varied with the length of NH4 + deprivation. Enriched KEGG pathways were also different when NH4 + was resupplied at different concentrations which may indicate reasons for tolerance of high NH4 + concentration. Using weighted gene co-expression network analysis (WGCNA), modules related to significant tea components, tea polyphenols and free amino acids, were identified. Hence, NH4 + could be regarded as a signaling molecule with the response of catechins shown to be higher than that of amino acids. The current work represents a comprehensive transcriptomic analysis of plant responses to NH4 + and reveals many potential genes regulated by NH4 + in tea plants. Such findings may lead to improvements in nitrogen efficiency of tea plants.

2.
Chem Commun (Camb) ; 58(60): 8384-8387, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35792136

RESUMO

A high-conductivity thiocyanate ionic liquid (EMIMSCN) was introduced into perovskite solar cells for the first time. The high conductivity of EMIMSCN ensures an adequate supply of free SCN- anions and EMIM+ cations, so as to multifunctionally passivate the I vacancy and Pb-I antisite defects and realize an optimized interfacial energy level. Consequently, the devices with EMIMSCN treatment achieve a high PCE of 22.55% with substantial enhancement in stability. This simple and efficient strategy provides new insights into the selection of passivation agents for efficient and stable PSCs.

3.
Angew Chem Int Ed Engl ; 61(25): e202204148, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35384201

RESUMO

Defect passivation via post-treatment of perovskite films is an effective method to fabricate high-performance perovskite solar cells (PSCs). However, the passivation durability is still an issue due to the weak and vulnerable bonding between passivating functional groups and perovskite defect sites. Here we propose a cholesterol derivative self-assembly strategy to construct crosslinked and compact membranes throughout perovskite films. These supramolecular membranes act as a robust protection layer against harsh operational conditions while providing effective passivation of defects from surface toward inner grain boundaries. The resultant PSCs exhibit a power conversion efficiency of 23.34 % with an impressive open-circuit voltage of 1.164 eV. The unencapsulated devices retain 92 % of their initial efficiencies after 1600 h of storage under ambient conditions, and remain almost unchanged after heating at 85 °C for 500 h in a nitrogen atmosphere, showing significantly improved stability.

4.
Physiol Plant ; 174(1): e13646, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35129836

RESUMO

As a preferred nitrogen form, ammonium (NH4 + ) transport via specific transporters is particularly important for the growth and development of tea plants (Camellia sinensis L.). However, our understanding of the functions of the AMT family in tea plants is limited. We identified and named 16 putative AMT genes according to phylogenetic analysis. All CsAMT genes were divided into three groups, distributed on 12 chromosomes with only one segmental duplication repetition. The CsAMT genes showed different expression levels in different organs, and most of them were expressed mainly in the apical buds and roots. Complementation analysis of yeast mutants showed that CsAMTs restored the uptake of NH4 + . This study provides insights into the genome-wide distribution and spatial expression of AMT genes in tea plants.


Assuntos
Compostos de Amônio , Camellia sinensis , Compostos de Amônio/metabolismo , Camellia sinensis/genética , Camellia sinensis/metabolismo , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Chá/metabolismo
5.
Bioinorg Chem Appl ; 2021: 5285625, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956341

RESUMO

Nanostructure CeO2 powders were synthesized using tea waste extract as gel precursor. The as-prepared samples were characterized by thermogravimetric analyzer (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Based on the TGA/DTG analysis, the intermediates of cerium chloride hydrates (CeCl3.4H2O and CeCl3.H2O) and cerium anhydrous (CeCl3) were produced, and the formation temperature of CeO2 was estimated to be 773 K. The cubic fluorite structure of CeO2 was detected to be the predominant species and was completely formed at the calcination temperature of 773K-1073 K with a crystal size between 8.8 and 11.4 nm based on the XRD measurement. Moreover, the main chemical state of ceria on the surface of the synthesized samples was confirmed to be tetravalent ceria by XPS. All samples show a strong Raman signal at a well-defined chemical shift of 463 cm-1 and a significant symmetry feature was observed, suggesting that the tetravalent ceria is the dominant species throughout the bulk sample. All the synthesized CeO2 calcined at different temperatures showed higher adsorption efficiency for Congo red (CR) compared with commercial CeO2. The adsorption efficiency maintained a steady state of more than 95% when the concentration of CR and adsorption temperature were varied in this study. The kinetic analysis showed that the second-order model was the appropriate model to interpret the adsorption behavior of synthesized CeO2. The calculated adsorption capacity derived from the second-order model is in good agreement with the experimental data. The isotherm analysis revealed that the Freundlich and D-R models fit well for the synthesized CeO2 and represent physisorption with a multilayer mechanism. The thermodynamic parameters, including the changes in Gibb's free energy, enthalpy, and entropy, suggested that the adsorption of CR on the synthesized CeO2 sample was a spontaneous and endothermic process.

6.
Molecules ; 24(8)2019 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-31010195

RESUMO

As a hydrogen storage material, Zr2Fe alloy has many advantages such as fast hydrogen absorption speed, high tritium recovery efficiency, strong anti-pulverization ability, and difficulty self-igniting in air. Zr2Fe alloy has lower hydrogen absorption pressure at room temperature than LaNi5 alloy. Compared with the ZrVFe alloy, the hydrogen release temperature of Zr2Fe is lower so that the material can recover hydrogen isotopes at lower hydrogen concentration efficiently. Unfortunately, the main problem of Zr2Fe alloy in application is that a disproportionation reaction is easy to occur after hydrogen absorption at high temperature. At present, there is little research on the generation and influencing factors of a disproportionation reaction in Zr2Fe alloy. In this paper, the effects of temperature and hydrogen pressure on the disproportionation of Zr2Fe alloy were studied systematically. The specific activation conditions and experimental parameters for reducing alloy disproportionation are given, which provide a reference for the specific application of Zr2Fe alloy.


Assuntos
Ligas/química , Hidrogênio/química , Temperatura
7.
RSC Adv ; 9(1): 408-428, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-35521580

RESUMO

Magnesium hydride and its compounds have a high hydrogen storage capacity and are inexpensive, and thus have been considered as one of the most promising hydrogen storage materials for on-board applications. Nevertheless, Mg/MgH2 systems suffer from great drawbacks in terms of kinetics and thermodynamics for hydrogen uptake/release. Over the past decades, although significant progress has been achieved with respect to hydrogen sorption kinetics in Mg/MgH2 systems, their high thermal stability remains the main drawback, which hinders their practical applications. Accordingly, herein, we present a brief summary of the synthetic routes and a comprehensive overview of the advantages and disadvantages of the promising strategies to effectively tune the thermodynamics of Mg-based materials, such as alloying, nanostructuring, metastable phase formation, changing reaction pathway, and nano Mg-based composites. Among them nanostructuring and metastable phase formation, which have the superiority of changing the thermodynamics without affecting the hydrogen capacity, have attracted increasing interest in this field. To further optimize the hydrogen storage performance, we specially emphasize novel nanostructured materials, which have the advantage of combining alloy engineering, nanostructuring and the synergistic effect to change the thermodynamics of Mg/MgH2 to some extent. Furthermore, the remaining challenges and the directions of further research on MgH2, including the fundamental mechanism of the Mg-H bond instability, advanced synthetic routes, stabilizing nanostructures, and predicting novel composite materials, are proposed.

8.
Phys Chem Chem Phys ; 17(20): 13606-12, 2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-25940663

RESUMO

In this paper, the gaseous and electrochemical hydrogen storage properties of 200 nm Mg-Pd thin films with different morphologies have been investigated. The results show that Mg-Pd films become porous with the increase of substrate temperature. Porous Mg-Pd films exhibit superior gaseous and electrochemical hydrogen storage behaviors under mild conditions, including rapid hydrogen sorption kinetics, a large hydrogen storage amount, high electrochemical discharge capacity, and a fast hydrogen diffusion rate. The excellent behaviors of porous Mg-Pd films might be ascribed to the significantly shortened hydrogen diffusion paths and the large contact areas between the hydrogen gas and the solid Mg phases, which are elucidative for the development and applications of thick Mg-Pd films.

9.
Zhongguo Gu Shang ; 22(2): 90-2, 2009 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-19281007

RESUMO

OBJECTIVE: To investigate the effects of antibiotic-PMMA (polymethyl-methacrylate) beads combined with external fixator in treatment of infected fracture nonunion. METHODS: Twenty-two cases of infected fracture-nonunions were reviewed involving 20 male and 2 female with an average age of 34.68 years (ranging 21 to 74 years). The data consisted of 9 cases of tibial fractures, 2 distal fractures of the femur, 6 femoral shaft fractures, 3 intertrochanteric fracture of the femur and 2 humeral shaft fractures. The procedure included thorough debridement to wipe out dead bone and granulation tissue, then antibiotic-PMMA bead chains imbedded into the dead space. One week later, secondary debridement was performed, antibiotic-PMMA bead chains were changed according to result of bacterial culture and susceptibility test, and fractures were stabilized with external fixator. Three months after debridement, antibiotic-PMMA bead chains were taken out and bone graft with autogenous iliac cancellous bone chips was performed. RESULTS: The mean follow-up period was 19.98 months (ranging 15 to 28 months). Infection was controlled in 20 cases. One tibial fracture and 1 intertrochanteric fracture of the femur needed repeated debridement 2 and 3 months after bone grafting respectively,because of infection recurrence and sinus formation. All 22 cases achieved bony union averaged 15.09 weeks after bone grafting with a range of 8 to 24 weeks. CONCLUSION: Thorough debridement, imbedding antibiotic-PMMA bead chains combined with external fixator and staged bone grafting has proven to be effective and simple for treatment of infected fracture nonunion. The antibiotic bead delivers high tissue levels,obliterates dead space, aids bone repair.


Assuntos
Antibacterianos/uso terapêutico , Doenças Ósseas Infecciosas/tratamento farmacológico , Doenças Ósseas Infecciosas/microbiologia , Fraturas Ósseas/complicações , Fraturas não Consolidadas/complicações , Adulto , Idoso , Doenças Ósseas Infecciosas/cirurgia , Transplante Ósseo , Fixadores Externos , Feminino , Seguimentos , Fraturas Ósseas/tratamento farmacológico , Fraturas Ósseas/cirurgia , Fraturas não Consolidadas/tratamento farmacológico , Fraturas não Consolidadas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Polimetil Metacrilato/química , Adulto Jovem
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