Persistent greening against drying in northeast Asian semiarid grasslands:Asymmetrical responses of direct and legacy effects to intensified drought

Despite experiencing a decadal shift towards drought conditions at the end of the 2Oth century,semiarid grasslands in northeast Asia(NEA)exhibited an evident greening trend from 1982 to 2020.However,the mechanism behind this phenomenon remains unclear.Hence,we analysed the interdecadal changes in vegetation response to drought on the basis of the standardised precipitation evapotranspiration index(SPEI)and Global Inventory Modelling and Mapping Studies LAI4g datasets,with an emphasis on the differences between direct and legacy effects(as measured by resilience),to explore the mechanism of persistent grassland greening.Results revealed that during the post-drought shift period(2000-2020),the sudden decrease in the water content of the intermediate soil layer triggered an intensified vegetation response to drought.Specifically,although direct effects and resilience were amplified,they exhibited asymmetric changes.Resilience was stronger than direct effects,and this difference increased with increasing drought(drought recovery)levels.These combined effects may account for persistent greening against intensified drying in the semiarid grasslands in NEA.Given the projected exacerbation of future droughts,this study holds notable importance for comprehending the long-term change dynamics of dryland ecosystems.

In-stent Anchoring Facilitating Side-branch Balloon Delivery for Final Kissing： A Prospective, Single-center Registry Study

Background：Recrossing the compromised side branch （SB） with a balloon is sometimes technically challenging.The aim of this study was to evaluate whether in-stent anchoring （ISA） is safe and effective to facilitate SB balloon delivery for final kissing.Methods：One hundred and fifty-nine consecutive patients were included （166 bifurcation lesions） in this prospective,single-center registry.ISA was used as a bailout method after unsuccessful SB crossing using conventional techniques,including low-profile balloons.Technique success was defined as SB balloon delivery and final kissing.Results：Kissing-balloon delivery was successfully performed with conventional strategies in 149 of 166 lesions （89.8%）.In the remaining 17 lesions （10.2%）,recrossing of the main vessel stent strut was not successful;therefore,ISA was attempted.The balloon successfully crossed the stent struts,and final kissing was achieved in 15 of 17 lesions （88.2%）.Total final kissing was achieved in 164 of 166 lesions （98.8%）,with success rates of 100% in the single-stent group and 97.6% in the two-stent group.Two cases without balloon delivery had complex bifurcation lesions with severe calcification.There was no vessel dissection in the anchoring zone.Conclusions：ISA is safe and effective for recrossing stent struts when conventional low-profile balloons have failed.However,large-scale trials are warranted for further evaluation.