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Global climate change is increasing the frequency and intensity of drought and salt stress worldwide, with profound impacts on tree growth and survival. However, the response of plant hydraulic transport and carbon balance to combined drought and salt stress remains unclear. This study investigated the leaf physiological traits, stem xylem hydraulic traits, and nonstructural carbohydrate concentration of Robinia pseudoacacia seedlings under normal irrigation treatment (CK, freshwater at 80–100% FC); salt stress treatment (SS, 0.3% soil salinity with freshwater); drought stress treatment (DS, withholding irrigation); and combined drought and salt treatments (SDS, 0.3% soil salinity withholding irrigation). Our results showed that the leaf physiological traits responded differently to different treatments. DS and SDS treatment significantly decreased leaf water potential and stomatal conductance, while SS treatment did not. DS treatment increased stomatal density but decreased stomatal area to adapt to water deficit, while SS and SDS treatment decreased stomatal length or width. In terms of xylem hydraulic traits, SS, DS and SDS significantly decreased xylem specific hydraulic conductivity by 47%, 42% and 49%, while percent loss of conductivity (PLC) significantly increased by 81% and 62% in DS and SDS, but the PLC of SS was not increased significantly. Additionally, net photosynthetic rate and transpiration rate significantly decreased in SS, DS and SDS, while leaf water use efficiency significantly increased. The chlorophyll content index and maximum light quantum efficiency of photosystem II were also decreased. For nonstructural carbohydrate, the soluble sugars, starch and total non-structural carbohydrate were significantly decreased in DS in specific tissues, showing reductions of 42%, 68%, and 56% in leaves, 69%, 61%, and 62% in stem, and 30%, 59%, and 57% in root. Our findings provide evidence that salt addition alleviated drought stress by improving hydraulic traits and carbohydrate reserves, which is expected to contribute to predicting future vegetation dynamics under climate change. [ABSTRACT FROM AUTHOR]

In this study, our objective is to investigate the anisotropic deformation behavior and the indentation size effect (ISE) of monocrystalline barium fluoride (BaF2) using nanoindentation experiments with a diamond Berkovich indenter. BaF2 is known for its anisotropy, which results in significant variations in its mechanical properties. This anisotropy poses challenges in achieving high processing quality in ultra-precision machining. Through our experiments, we observed numerous pop-in events in the load–displacement curves, indicating the occurrence of plastic deformation in BaF2 crystals, specifically in the (100), (110), and (111) orientations; these pop-in events were observed as the indentation depth increased to 56.9 nm, 58.2 nm, and 57.8 nm, respectively. The hardness–displacement and elastic modulus–displacement curves were obtained from the tests exhibiting the ISE. The nanoindentation hardness of BaF2 is found to be highly dependent on its crystallographic orientation. Similarly, for BaF2 in the (100) orientation, the range is from 2.43 ± 0.74 and 1.24 ± 0.12 GPa. For BaF2 in the (110) orientation, the values range from 2.15 ± 0.66 to 1.18 ± 0.15 GPa. For BaF2 in the (111) orientation, the values range from 2.12 ± 0.53 GPa to 1.19 ± 0.12 GPa. These results highlight the significant influence of crystallographic orientation on the mechanical properties of BaF2. To better understand the ISE, we employed several models including Meyer's law, the Nix–Gao model, the proportional specimen resistance (PSR) model, and the modified PSR (mPSR) model, and compared them with our experimental results. Among these models, the mPSR model demonstrated the best level of correlation ( R 2 > 0.9999 ) with the experimental measurements, providing a reliable description of the ISE observed in BaF2. Our reports provide valuable insights into the anisotropic mechanical characteristics of BaF2 materials and serve as a theoretical guide for the ultra-precision machining of BaF2. [ABSTRACT FROM AUTHOR]

Cavitation resistance is a key trait for characterizing the drought adaption in plants and is usually presented in terms of vulnerability curves. Three principal techniques have been developed to produce vulnerability curves, but curves generated with centrifugation are reported to suffer from artifacts when applied to long-vesseled species. The main cause of this artifact is the issue of open vessels, resulting in a nano-particle effect that may seed premature embolism. We used two methods to test the potential mechanism behind the nano-particle effect in centrifuge-based vulnerability curves. A four-cuvette rotor system based on a traditional Cochard rotor was designed to inhibit effervescence while injecting water, but the recalcitrant vulnerability curves in Robinia could not be eliminated. There may be multiple sources, besides effervescence, of hypothetical nano-particles: they may arise from cut surfaces or they may be always present in the injected water, leading to the premature embolisms. To prevent the entry of the hypothetical nano-particles, water extraction curves in terms of PLV (percentage loss volume of extracted water from stems) vs tensions were constructed. The PLV curves of Robinia showed s-shaped characteristics after subtracting the first Weibull components from water extraction curves, which were not related to the water loss from vessels according to dye staining experiments. The differences between T 50 (xylem tension at which 50% of hydraulic conductivity is lost) in mean PLV curve and T 50 in percentage loss of conductivity curves determined by the four-cuvette rotor system and by the bench dehydration method were 3.9 MPa and 0.7 MPa, respectively. Hence, PLV curves may be a valid way to measure the cavitation resistance in long-vesseled species with centrifugation. Keeping bark intact in the process of measurement is recommended, otherwise it would increase evaporation from the entire system. [ABSTRACT FROM AUTHOR]

Background: Radiotherapy and laser resection are established treatment modalities for early glottic carcinoma. To date, there is no confirmed conclusion which treatment is better for early glottic cancer. The objective of this study was to conduct a meta-analysis to compare the voice outcomes after laser resection (LS) and radiotherapy (RT) of Tis-T1N0M0 glottic carcinoma., Methods: we searched the relevant electronic studies and performed a meta-analysis based on 13 published studies. The Chi-square based I(2)-statistic test was performed to evaluate possible heterogeneity across the studies. Additionally, random-effects models were used to calculate mean differences with 95% confidence intervals (CIs)., Results: Overall, a total of 13 published studies were included in our study, with 368 patients in the RT group and 440 patients in the LS group, respectively. No significant differences in Voice Handicap Index (VHI), jitter and shimmer were found between RT and endoscopic LS among patients with Tis-T1N0M0 glottic carcinoma and T1aN0M0 laryngeal cancer. However, the acoustic voice analysis parameters of Fo values were significantly lower in RT group than that in LS group., Conclusion: The results from this meta-analysis support that the LS has more advantages than RT in terms of voice quality. However, more studies on voice outcome need to validate our findings.