ABSTRACT
Mixed cultivation with legumes may alleviate the nitrogen (N) limitation of monoculture Eucalyptus. However, how leaf functional traits respond to N in mixed cultivation with legumes and how they affect tree growth are unclear. Thus, this study investigated the response of leaf functional traits of Eucalyptus urophylla × Eucalyptus grandis (E. urophylla × E. grandis) and Dalbergia odorifera (D. odorifera) to mixed culture and N application, as well as the regulatory pathways of key traits on seedling growth. In this study, a pot-controlled experiment was set up, and seedling growth indicators, leaf physiology, morphological parameters, and N content were collected and analyzed after 180 days of N application treatment. The results indicated that mixed culture improved the N absorption and photosynthetic rate of E. urophylla × E. grandis, further promoting seedling growth but inhibiting the photosynthetic process of D. odorifera, reducing its growth and biomass. Redundancy analysis and path analysis revealed that leaf nitrogen content, pigment content, and photosynthesis-related physiological indicators were the traits most directly related to seedling growth and biomass accumulation, with the net photosynthetic rate explaining 50.9% and 55.8% of the variation in growth indicators for E. urophylla × E. grandis and D. odorifera, respectively. Additionally, leaf morphological traits are related to the trade-off strategy exhibited by E. urophylla × E. grandis and D. odorifera based on N competition. This study demonstrated that physiological traits related to photosynthesis are reliable predictors of N nutrition and tree growth in mixed stands, while leaf morphological traits reflect the resource trade-off strategies of different tree species.
ABSTRACT
The dearomative functionalization of aromatic compounds represents a fascinating but challenging transformation, as it typically needs to overcome a great kinetic barrier. Here, a catalyst-free dearomative rearrangement of o-nitrophenyl alkyne is successfully established by leveraging the remote oxygen transposition and a weak N-O bond acceleration. This reaction features high atom-, step- and redox-economy, which provides a divergent entry to a series of biologically important benzazepines and bridged polycycloalkanones. The reaction is proposed to proceed through a tandem oxygen transfer cyclization/(3 + 2) cycloaddition/(homo-)hetero-Claisen rearrangement reaction. The resulting polycyclic system is richly decorated with transformable functionalities, such as carbonyl, imine and diene, which enables diversity-oriented synthesis of alkaloid-like polycyclic framework.
Subject(s)
Alkaloids , Benzazepines , Alkaloids/chemistry , Cyclization , Cycloaddition Reaction , OxygenABSTRACT
AIM: To explore the role of gammadeltaT cells in the pathogenesis of allergic bronchial asthma. METHODS: Forty patients with Der.p and Der f allergy and partly-controlled asthma were involved in a random study. Besides the fact that all patients were treated with same basic treatment. Patients in group A were nebulized with 5 mL normal saline while group B with specific allergen twice a week for six months. The percentage of gammadeltaT cells in peripheral blood and induced sputum and the percentage of IL-4(+) and IFN-gamma(+) gammadeltaT cells were detected by flow cytometry(FCM) before and after treatment. RESULTS: The percentage of gammadeltaT cells in group B decreased after treatment, and the percentage of IFN-gamma(+) gammadeltaT cells in both peripheral blood and induced sputum increased significantly in group B than that in group A. CONCLUSION: gammadeltaT cells, which may participate in the pathogenesis of bronchial asthma, may contribute to the prevention and treatment of bronchial asthma by desensitization of allergen nebulization.
