Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 13(1): 14536, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37666872

RESUMO

The seed oil of Echium plantagineum L. is rich in unsaturated fatty acids. With the gradual development of the value of echium oil in food, medical care and cosmetics, the corresponding market demand has also increased. The selection of suitable cultivars and the increase of yield per unit area has also become one of the main objectives of current breeding and cultivation of E. plantagineum. To effectively use the local photothermal resources, to improve the use of light energy by E. plantagineum, and to enhance the growth and yield of E. plantagineum. E. plantagineum cultivars Blue Bedder and Mixed Bedding were used as research subjects to study the effects of different sowing dates (1 May, 8 May, 15 May, 22 May and 29 May) on the photosynthetic characteristics and yield of E. plantagineum. Under the same cultivar conditions, with the delay in sowing date, the leaf chlorophyll content (SPAD), photosynthetic rate (Pn), transpiration rate (Tr), stomatal limitation value (Ls), photochemical quenching (qP), electron transfer rate (ETR), actual photochemical efficiency (ΦpsII) and yield of Blue Bedder decreased and reached a maximum at T1, while the SPAD, Pn, Tr, water use efficiency (WUE), Ls, initial fluorescence (Fo), maximum fluorescence (Fm), qP, ETR, ΦpsII and yield of Mixed Bedding reached the maximum at T4. Blue Bedder should be sown early at T1 and Mixed Bedding late at T4 during planting, which will help to improve the photosynthetic characteristics and grain yield of E. plantagineum.


Assuntos
Echium , Humanos , Fluorescência , Melhoramento Vegetal , Clorofila , Grão Comestível
2.
RSC Adv ; 13(15): 9945-9953, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37006345

RESUMO

For decades, corrosion has been classified into many categories according to the microstructural morphology of the chemical reaction products. Until recently, the development of quantum chemistry has simplified the fundamental corrosion mechanism into only two processes: electrochemical dissolution and hydrogen evolution reaction (HER). Although Cr and Ni elements have been found to segregate towards the surface of stainless steel to form a protective layer and prevent Fe dissolution, the understanding of the exact chemistry on top of the Fe surface has not been reported in previous studies. In this study, we have identified suitable doping sites for simultaneous doping of several Cr and Ni atoms, and quantified the effects of different alloy compositions (Fe12Cr3Ni1, Fe11Cr4Ni1, Fe11Cr3Ni2, Fe10Cr4Ni2, Fe10Cr3Ni3) on the stability from two aspects: electron transfer and atomic dissolution. It was found that the doping atoms are more likely to be dispersed rather than aggregated in solid solution. When Cr atoms are symmetrically distributed and Ni atoms are located in the center, it is the site arrangement with the highest work function and stability. Fe10Cr4Ni2 has been found to possess a higher electron binding capacity and thus higher electrode potentials. This is determined by the change of dipole caused by both electronegativity difference between atoms and polarization between the doped layer and the substrate layer. By calculating the vacancy formation energy, it is shown that Fe11Cr4Ni2 is the perfect chemistry on top of the Fe(110) surface due to its high ability of preventing atomic dissolution.

3.
Plants (Basel) ; 12(5)2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36903903

RESUMO

Selections of drought-tolerant cultivars and drought-stress diagnosis are important for sugarcane production under seasonal drought, which becomes a crucial factor causing sugarcane yield reduction. The main objective of this study was to investigate the differential drought-response strategies of drought-resistant ('ROC22') and -susceptible ('ROC16') sugarcane cultivars via photosynthetic quantum efficiency (Φ) simulation and analyze photosystem energy distribution. Five experiments were conducted to measure chlorophyll fluorescence parameters under different photothermal and natural drought conditions. The response model of Φ to photosynthetically active radiation (PAR), temperature (T), and the relative water content of the substrate (rSWC) was established for both cultivars. The results showed that the decreasing rate of Φ was higher at lower temperatures than at higher temperatures, with increasing PAR under well-watered conditions. The drought-stress indexes (εD) of both cultivars increased after rSWC decreased to the critical values of 40% and 29% for 'ROC22' and 'ROC16', respectively, indicating that the photosystem of 'ROC22' reacted more quickly than that of 'ROC16' to water deficit. An earlier response and higher capability of nonphotochemical quenching (NPQ) accompanied the slower and slighter increments of the yield for other energy losses (ΦNO) for 'ROC22' (at day5, with a rSWC of 40%) compared with 'ROC16' (at day3, with a rSWC of 56%), indicating that a rapid decrease in water consumption and an increase in energy dissipation involved in delaying the photosystem injury could contribute to drought tolerance for sugarcane. In addition, the rSWC of 'ROC16' was lower than that of 'ROC22' throughout the drought treatment, suggesting that high water consumption might be adverse to drought tolerance of sugarcane. This model could be applied for drought-tolerance assessment or drought-stress diagnosis for sugarcane cultivars.

4.
Front Endocrinol (Lausanne) ; 12: 779365, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899612

RESUMO

Context: Long-acting recombinant human growth hormone (rhGH) has transformed growth hormone deficiency (GHD) treatment. However, the possibility and rationality for flexible time regimen are pending. Objective: We studied the efficacy of biweekly versus weekly PEGylated rhGH (PEG-rhGH) therapy in GHD children. Design Setting and Patients: This multicenter, phase IV trial with a non-inferiority threshold ≥20% enrolled 585 Tanner stage I GHD children. Intervention: Subjects randomly received 0.20 mg/kg once-weekly or biweekly PEG-rhGH, or 0.25 mg/kg.w rhGH once daily for 26 weeks. Main Outcome Measure: The primary outcome was height SD scores for chronological age (HtSDSCA) at week 26 and safety measurements including adverse events (AEs), IGF-2, and IGFBP-2 changes. Results: At week 26, the median HtSDSCA changed from -2.75, -2.82, and -2.78 to -2.31, -2.43, and -2.28 with weekly and biweekly PEG-rhGH, and daily rhGH, respectively. The difference in HtSDSCA was 0.17 ± 0.28 between weekly and biweekly PEG-rhGH, and 0.17 ± 0.27 between daily rhGH and biweekly PEG-rhGH, failing the non-inferiority threshold. Nevertheless, the height velocity of children receiving biweekly PEG-rhGH reached 76.42%-90.34% and 76.08%-90.60% that of children receiving weekly PEG-rhGH and daily rhGH, respectively. The rate of AEs was comparable among the groups. No statistical difference was observed in IGF-2 and IGFBP-2 levels among the groups. IGFBP-2 levels decreased over time in all groups, with no notable difference in IGF-2 and IGFBP-2 changes among the three treatment groups. Conclusions: Although notably promoted height velocity, biweekly PEG-rhGH failed the non-inferiority threshold as compared with either weekly PEG-rhGH or daily rhGH. Compared with short-term rhGH, long-acting PEG-rhGH did not significantly increase tumor-associated IGF-2 and IGFBP-2 expressions. Clinical Trial Registration: clinicaltrials.gov, identifier NCT02976675.


Assuntos
Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento Humano/administração & dosagem , Hormônio do Crescimento Humano/efeitos adversos , Criança , Pré-Escolar , China , Esquema de Medicação , Nanismo Hipofisário/tratamento farmacológico , Estudos de Equivalência como Asunto , Feminino , Hormônio do Crescimento Humano/deficiência , Humanos , Masculino , Polietilenoglicóis/química , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/química , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...