RESUMO
The distribution and diversity of woody vegetation are crucial for understanding the structure and ecology of urban forests. As urbanization accelerates, the construction and composition of urban forests vary significantly along the urban-rural gradient. Qingdao's urban forests offer an opportunity to test the relationship between the diversity of woody plants and the urban-rural gradient. We classified the urban-rural gradient using imperviousness and construction time, then investigated the diversity of woody plants in Qingdao's urban forests under different urban-rural gradients and tested the reasonableness of their allocation. Correlation analysis found that the diversity index of woody plants in urban forests was highly connected to the urban-rural gradient (by imperviousness: rMargalef Index = -0.589, rShannon-Wiener Index = -0.373, rPielou Index = -0.170, rSimpson Index = 0.272/by construction time: rMargalef Index = -0.530, rShannon-Wiener Index = -0.360, rPielou Index = -0.148, rSimpson Index = 0.272/0.174). With a decrease in urbanization density, the Margalef (H), Shannon-Wiener (H'), and Simpson (D) indices all decreased while the Pielou (E) index increased. The four diversity indices showed a substantial correlation with one another, but not with the Margalef and Pielou indices. The analysis utilizing the 10/20/30 rule of empirical demonstrates a clear irrationality in allocating shrub species in Qingdao's urban forests, and the distribution of tree species is reasonable. Based on the study results, strategies for optimizing and enhancing urban forests in Qingdao are proposed for different urban-rural gradients, respectively. This study can provide a scientific framework for urban biodiversity conservation and management in Qingdao and serve as a guide for urban forests and greening with comparable climates.
RESUMO
Designing high efficiency platinum (Pt)-based catalysts for methanol oxidation reaction (MOR) with high "non-CO" pathway selectivity is strongly desired and remains a grand challenge. Herein, PtRuNiCoFeGaPbW HEA ultrathin nanowires (HEA-8 UNWs) are synthesized, featuring unique cascaded p-d orbital hybridization interaction by inducing dual p-block metals (Ga and Pb). In comparison with Pt/C, HEA-8 UNWs exhibit 15.0- and 4.2-times promotion of specific and mass activity for MOR. More importantly, electrochemical in situ FITR spectroscopy reveals that the production/adsorption of CO (CO*) intermediate is effectively avoided on HEA-8 UNWs, leading to the complete "non-CO" pathway for MOR. Theoretical calculations demonstrate the optimized electronic structure of HEA-8 UNWs can facilitates a lower energy barrier for the "non-CO" pathway in the MOR.
RESUMO
The new tea cultivar Ziyan has a high content of anthocyanin and ester catechins in the raw material, but the conventional processing and application methods are limited. To explore its application potential, the freeze-drying method was used to prepare microcapsules with an embedding time of 30 min, solid content of 30%, and core to wall ratio of 1:10 (g/g). The anthocyanin recovery was 95.94 ± 0.50%, and the encapsulation efficiency was 96.15 ± 0.11%. The stability of microcapsules and composite wall materials was evaluated in the simulation system. Results showed that microcapsules employing a maltodextrin-gum arabic ratio of 2:8 (w/w) as the wall material significantly reduced degradation rates, extending anthocyanin half-life under various storage conditions. Characterization indicated improved physical properties of Ziyan anthocyanin powder post-microencapsulation. FT-IR and DSC- revealed the formation of a new phase between anthocyanins and wall materials, leading to increased enthalpy and enhanced thermal stability. The microencapsulation results of this experiment proved that the storage stability of anthocyanin was effectively enhanced.
RESUMO
CAR-like membrane protein (CLMP) is a tight junction-associated protein whose mutation is associated with congenital short bowel syndrome (CSBS), but its functions in colorectal cancer (CRC) remain unknown. Here, we demonstrate that CLMP is rarely mutated but significantly decreased in CRC patients, and its deficiency accelerates CRC tumorigenesis, growth, and resistance to all-trans retinoic acid (ATRA). Mechanistically, CLMP recruits ß-catenin to cell membrane, independent of cadherin proteins. CLMP-mediated ß-catenin translocation inactivates Wnt(Wingless and INT-1)/ß-catenin signaling, thereby suppressing CRC tumorigenesis and growth in ApcMin/+, azoxymethane/dextran sodium sulfate (AOM/DSS), and orthotopic CRC mouse models. As a direct target of Wnt/ß-catenin, cytochrome P450 hydroxylase A1 (CYP26A1)-an enzyme that degrades ATRA to a less bioactive retinoid-is upregulated by CLMP deficiency, resulting in ATRA-resistant CRC that can be reversed by administering CYP26A1 inhibitor. Collectively, our data identify the anti-CRC role of CLMP and suggest that CYP26A1 inhibitor enable to boost ATRA's therapeutic efficiency.
Assuntos
Neoplasias Colorretais , beta Catenina , Camundongos , Animais , Humanos , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , beta Catenina/metabolismo , Ácido Retinoico 4 Hidroxilase/genética , Ácido Retinoico 4 Hidroxilase/metabolismo , Tretinoína/farmacologia , Tretinoína/metabolismo , Transformação Celular Neoplásica , Carcinogênese , Neoplasias Colorretais/metabolismo , Via de Sinalização Wnt , Linhagem Celular TumoralRESUMO
Intratumor heterogeneity (ITH) is a barrier to effective therapy. However, it is largely unknown how ITH is established at the onset of tumor progression, such as in colorectal cancer (CRC). Here, we integrate single-cell RNA-seq and functional validation to show that asymmetric division of CRC stem-like cells (CCSC) is critical for early ITH establishment. We find that CCSC-derived xenografts contain seven cell subtypes, including CCSCs, that dynamically change during CRC xenograft progression. Furthermore, three of the subtypes are generated by asymmetric division of CCSCs. They are functionally distinct and appear at the early stage of xenografts. In particular, we identify a chemoresistant and an invasive subtype, and investigate the regulators that control their generation. Finally, we show that targeting the regulators influences cell subtype composition and CRC progression. Our findings demonstrate that asymmetric division of CCSCs contributes to the early establishment of ITH. Targeting asymmetric division may alter ITH and benefit CRC therapy.