Can leaf drought tolerance predict species abundance and its changes in tropical-subtropical forests?

Climate change has resulted in an increase in drought severity in the species-rich tropical and subtropical forests of southern China. Exploring the spatiotemporal relationship between drought-tolerance trait and tree abundance provides a means to elucidate the impact of droughts on community assembly and dynamics. In this study, we measured the leaf turgor loss point (πtlp) for 399 tree species from three tropical forest plots and three subtropical forest plots. The plot area was 1 ha and tree abundance was calculated as total basal area per hectare according to the nearest community census data. The first aim of this study was to explore πtlp abundance relationships in the six plots across a range of precipitation seasonality. Additionally, three of the six plots (two tropical forests and one subtropical forest) had consecutive community censuses data (12-22 years) and the mortality ratios and abundance year slope of tree species were analyzed. The second aim was to examine whether πtlp is a predictor of tree mortality and abundance changes. Our results showed that tree species with lower (more negative) πtlp were more abundant in the tropical forests with relative high seasonality. However, πtlp was not related to tree abundance in the subtropical forests with low seasonality. Moreover, πtlp was not a good predictor of tree mortality and abundance changes in both humid and dry forests. This study reveals the restricted role of πtlp in predicting the response of forests to increasing droughts under climate change.

Tree growth is correlated with hydraulic efficiency and safety across 22 tree species in a subtropical karst forest.

Karst forests are habitats in which access to soil water can be challenging for plants. Therefore, safe and efficient xylem water transport and large internal water storage may benefit tree growth. In this study, we selected 22 tree species from a primary subtropical karst forest in southern China and measured their xylem anatomical traits, saturated water content (SWC), hydraulic conductivity (Ks) and embolism resistance (P50). Additionally, we monitored growth of diameter at breast height (DBH) in 440 individual trees of various sizes over three consecutive years. Our objective was to analyze the relationships between xylem structure, hydraulic efficiency, safety, water storage and growth of karst tree species. The results showed significant differences in structure but not in hydraulic traits between deciduous and evergreen species. Larger vessel diameter, paratracheal parenchyma and higher SWC were correlated with higher Ks. Embolism resistance was not correlated with the studied anatomical traits, and no tradeoff with Ks was observed. In small trees (5-15 cm DBH), diameter growth rate (DGR) was independent of hydraulic traits. In large trees (>15 cm DBH), higher Ks and more negative P50 accounted for higher DGR. From lower to greater embolism resistance, the size-growth relationship shifted from growth deceleration to acceleration with increasing tree size in eight of the 22 species. Our study highlights the vital contributions of xylem hydraulic efficiency and safety to growth rate and dynamics in karst tree species; therefore, we strongly recommend their integration into trait-based forest dynamic models.

The Application of the Nurse-Led Sedation and Analgesia Management in ICU after Heart Surgeries.

Aim: Traditional sedation management consists of doctors adjusting the dosage of sedative drugs or adding other drugs in combination according to the evaluation of nurses; the nurses then execute the orders. The nurses' passive execution in the process is not the ideal model for continuous evaluation and observation of sedation. This study aims to investigate the application and effects of nurse-provided procedural sedation and analgesia for patients in intensive care unit. Methods: The experimental group consisted of 354 heart surgery patients who received procedural sedation and analgesia from nurses from November 2020 to August 2021. The control group consisted of 301 patients who had had heart surgery and received the traditional sedation management program from January to October 2020. The differences in levels of the sedative effect, delirium, and unplanned extubation of patients between these two groups were compared. Results: There were no significant differences in baseline characteristics between the two groups (P > 0.05). It was found that both insufficient sedation and excessive sedation decreased in the experimental group when compared to the control group, while the appropriate proportion of sedation increased (72.41% versus 37.98%); the difference was statistically significant (P < 0.05). The incidence of delirium was lower for patients in the experimental group than for patients in the control group (37.01% versus 66.45%); the difference was statistically significant (P < 0.05). The incidence of unplanned extubation caused by patient factors was lower for the experimental group than for the control group, but the difference was not statistically significant (P > 0.05). Conclusion: The programmed sedation scheme led by nurses can improve the sedation effect and reduce the incidence of delirium. Implications for Practice. The management team gives the sedative goal and establishes the standard flowchart. The sedation management led by the nurse according to the goal and flowchart is better than the traditional sedation management.

In situ synthesis of self-assembled three-dimensional graphene-magnetic palladium nanohybrids with dual-enzyme activity through one-pot strategy and its application in glucose probe.

The self-assembled three-dimensional graphene nanohybrids with in situ-formed Fe3O4 and Pd nanoparticles on it (3DRGO_Fe3O4-Pd) are first synthesized by the one-pot solvothermal method, which have intrinsic peroxidase-like and oxidase-like activity. The catalytic mechanism is analyzed by the electron spin resonance (ESR), fluorescence, and electrochemical methods. The mimic enzyme catalytic activity of 3DRGO_Fe3O4-Pd is much higher than those of monometallic loaded nanohybrids and their physical mixture, probably caused by synergistic effect between Pd and Fe3O4 nanoparticles. The 3DRGO_Fe3O4-Pd nanohybrids was reproducible, stable, and reusable. After 10 cycles, the catalytic activity was still higher than 90%, and the morphology and structure were basically unchanged. Based on its high peroxidase-like activity, especially the enhanced affinity toward H2O2, a new colorimetric detection method for reduced glutathione (GSH) and glucose has been designed using H2O2 as an intermediary, which provides a simple, sensitive, and selective way to detect urine glucose of diabetes with a wide linear range and low detection limit.