Adaptation of Asia-Pacific forests to climate change

Climate change is a threat to the stability and productivity of forest ecosystems throughout the AsiaPacific region. The loss of forests due to climate-induced stress will have extensive adverse impacts on biodiversity and an array of ecosystem services that are essential for the maintenance of local economies and public health. Despite their importance, there is a lack of decision-support tools required to evaluate the potential effects of climate change on Asia-Pacific ecosystems and economies and to aid in the development of regionally appropriate adaptation and mitigation strategies. The project Adaptation of AsiaPacific Forests to Climate Change, summarized herein,aims to address this lack of knowledge and tools and to provide support for regional managers to develop effective policy to increase the adaptive capacity of Asia-Pacific forest ecosystems. This objective has been achieved through the following activities：（1） development of a highresolution climate downscaling model, Climate AP, applicable to any location in the region;（2） development of climate niche models to evaluate how climate change might affect the distribution of suitable climatic conditions for regionally important tree species;（3） development and application of forest models to assess alternative management strategies in the context of management objectives and the projected impacts of climate change;（4） evaluation of models to assess forest fire risk and the relationship between forest fire and climate change;（5） development of a technique to assess ecosystem carbon storage using Li DAR; and（6） evaluation of how vegetation dynamics respond to climate change using remote sensing technology. All project outputs were developed with a focus on communication and extension to facilitate the dissemination of results to regional forest resource managers to support the development of effective mitigation and adaptation policy.

Erratum to: Adaptation of Asia-Pacific forests to climate change

During the final preparation of this manuscript, Craig R.Nitschke's name was inadvertently omitted from the list of authors. The corresponding author and all co-authors acknowledge that this was an error and that his name should be included amongst the authors of the manuscript.

Piezoelectric film promotes skin wound healing with enhanced collagen deposition and vessels regeneration via upregulation of PI3K/AKT

Skin wounds are common in accidental injuries,and the intricacies of wound repair are closely linked to endogenous electric fields.Electrical stimulation plays a pivotal role in the restorative processes of skin injuries,encompassing collagen deposition,angiogenesis,inflammation,and re-epithelialization.Employing electrical stimulation therapy replicates and enhances the effects of endogenous wound electric fields by applying an external electric field to the wound site,thereby promoting skin wound healing.In this study,we developed a self-powered repetitive mechanical impacts-electrical stimulation(RMI-ES)system utilizing a BaTiO3/polydimethylsiloxane(PDMS)piezoelectric composite film.Compared to conventional electrical stimulation devices,the fabricated piezoelectric composite film efficiently harvests energy from the pressure applied by the stimulation device and the tensile force occurring during natural rat activities.The results demonstrated that piezoelectric stimulation generated by the composite membrane expedited the cell cycle,promoting fibroblast proliferation.Additionally,piezoelectric stimulation induced favorable changes in fibroblast gene expression,including increased expression of transforming growth factor-β1(TGF-β1),connective tissue growth factor(CTGF),collagen 1,collagen 3,vascular endothelial growth factor(VEGF),and alpha-smooth muscle actin(α-SMA),while reducing interleukin-6(IL-6)expression.Transcriptome analysis revealed that piezoelectric stimulation may induce fibroblast migration,proliferation,and collagen expression by influencing PI3K/AKT serine/threonine kinase(AKT)pathways.Further confirmation through the addition of the PI3K inhibitor LY294002 validated that piezoelectric stimulation can regulate the repair process after skin injury through the pathway.Importantly,in vivo results demonstrated that the electric field at the wound site effectively promoted wound healing,reduced inflammation,and stimulated collagen deposition and neovascularization.This study emphasizes the role of the piezoelectric membrane as an effective,safe,and battery-free electrical stimulator crucial for skin wound healing.

Fabrication of graphene nanoplatelets reinforced Mg matrix composites via powder thixoforging

A powder thixoforging route combined with slurry based mixing process was proposed to fabricate graphene nanoplatelets(GNPs) reinforced magnesium matrix composites(MgMCs). The originally spherical and ball-milled ZK60 powders were used as matrices, respectively.The mixing of 0.05 wt.% GNPs with the spherical powder led to GNPs clusters and degraded the mechanical properties of the composite.In contrast, with the addition of an optimal content(0.1 wt.%) of GNPs, the composite fabricated from ball-milled powder achieved a joint enhancement in tensile yield strength(52%) and fracture toughness(19%), demonstrating a pronounced strengthening efficiency of 650% and a good balance between strength and toughness. The ball-milled powder endowed the composite with a homogenous distribution of GNPs and a denser microstructure with reduced Mg-Zn eutectics, and the thixoforging process offered a well-bonded Mg/GNP interface, making full use of the strengthening and toughening potential of GNPs. Theoretical predication based on a modified shear-lag model suggested that load transfer dominated the strengthening mechanisms. In-situ tensile tests verified that crack deflection, secondary cracks and GNPs bridging mainly accounted for the toughening mechanisms. A numerical model with consideration of GNPs orientations was also established to understand the toughening effect from GNPs bridging.

Visible-light responsive organic nano-heterostructured photocatalysts for environmental remediation and H2 generation

The ease of molecular design and functionalization make organic semiconductors(OSCs)unit the electronic,chemical and mechanical benefits with a material structure.The easily tunable optoelectronic properties of OSCs also make it promising building blocks and thereby provide more possibilities in photocatalytic applications.So far,organic nanostructures have gained great impetus and found wide applications in photocatalytic organic synthesis,remediation of water and air,as well as water splitting into hydrogen.But they still suffer from low charge separation and sunlight absorption efficiencies.Accordingly,many strategies have been explored to address these issues,and one of the most effective solutions is to develop nano-heterostructures.To give an impulse for the developments of this field,this review attempts to make a systematic introduction on the recent progress over the rational design and fabrication of organic nano-heterostructured photocatalysts,including the types of organic semiconductor/semiconductor(OSC/SC),organic semiconductor/metal(OSC/M),organic semiconductor/carbon(OSC/C),and OSC-based multinary nano-heterostructures.The emphasis is placed on the structure/property relationships,and their photocatalytic purposes in environmental and energy fields.At last,future challenges and perspectives for the ongoing development of OSC materials and their use in high-quality optoelectronic devices are also covered.

Association of serum potassium level with early and late mortality in very elderly patients with acute kidney injury

Background:The kidneys play a central role in serum potassium(K+)homeostasis,and their dysfunction leads to electrolyte disorders.We aimed to examine the relationship between different levels of K+and mortality among very elderly patients with acute kidney injury(AKI).Methods:We retrospectively enrolled very elderly patients(≥75 years)with AKI from the hospital information system of the Chinese PLA General Hospital from January 1,2007 to December 31,2018.All-cause mortality was examined according to six predefined K+levels:<3.50 mmol/L,3.50-3.79 mmol/L,3.80-4.09 mmol/L,4.10-4.79 mmol/L,4.80-5.49 mmol/L,and≥5.50 mmol/L.We estimated the risk of all-cause mortality using the multivariable adjusted Cox proportional hazard model with the normal K+level at 3.50-3.79 mmol/L as a reference.Results:In total,747 patients were deemed suitable for the final evaluation.The median age of the 747 par-ticipants was 88(84-91)years.After 90 days,the mortality rates in the six strata were 28.3%,21.9%,30.1%,35.4%,45.2%,and 58.3%,respectively.In the multivariable adjusted analysis,patients with K+levels of 4.10-4.79 mmol/L(hazard ratio[HR]:1.638;95%confidence interval[CI]:1.016-2.642),4.80-5.49 mmol/L(HR:2.585;95%CI:1.524-4.384),and≥5.50 mmol/L(HR:2.587;95%CI:1.495-4.479)had an increased risk of all-cause mortality.After 1 year,the mortality rates in the six strata were 44.8%,41.1%,45.1%,51.8%,63.1%,and 76.3%,respectively.In the multivariable adjusted analysis,patients with K+levels of 4.10-4.79 mmol/L(HR:1.452;95%CI:1.014-2.079),4.80-5.49 mmol/L(HR:2.151;95%CI:1.427-3.241),and≥5.50 mmol/L(HR:2.341;95%CI:1.514-3.620)had an increased risk of all-cause mortality.Conclusion:Increased serum K+levels,including levels of 4.10-5.49 mmol/L and≥5.50 mmol/L,were associated with a significantly increased short-and long-term risk of death.Serum K+has the potential to be a marker of disease severity among very elderly patients with AKI.

Duration of acute kidney injury predicts 90-day mortality and chronic kidney disease progression in elderly patients

Background:This study evaluated the prognostic impact of acute kidney injury(AKI)duration on 90-d mortality and new-onset chronic kidney disease(CKD)progression in elderly patients.Methods:We retrospectively enrolled elderly patients(≥75 years;n=693)from the Chinese PLA General Hospital between January 1,2007 and December 31,2018.The 2012 Kidney Disease Improving Global Outcomes(KDIGO)defined serum creatinine(Scr)criteria were used to identify and classify AKI.Patients were divided into transient AKI(T-AKI)and persistent AKI(P-AKI)groups based on whether Scr levels returned to baseline within 48 h post-AKI.We further classified P-AKI based on AKI duration:(1)short duration:resolving AKI lasting 3–4 days;(2)medium duration:resolving AKI lasting 5–7 days;and(3)long duration:AKI lasting>7 days.Results:Among patients,62(9.0%)had T-AKI(1–2 days),104(15.0%)had short-duration,140(20.2%)had medium-duration,and 387(55.8%)had long-duration.In total,209(30.2%)died within 90 days;122(25.2%)developed CKD.After adjusting for multiple covariates,duration of AKI(3–4 days:hazard ratio[HR]=2.512;P=0.045;5–7 days:HR=3.154;P=0.015;>7 days:HR=6.212;P<0.001)was significantly associated with a higher 90-day mortality.Longer AKI duration(3–4 days:odds ratio[OR]=0.982;P=0.980;5–7 days:OR=1.322;P=0.661;>7 days:OR=7.007;P<0.001)was significantly associated with new-onset CKD of survivors.Conclusion:AKI duration is useful for predicting poorer clinical outcomes in elderly patients,emphasizing the importance of identifying an appropriate treatment window for early intervention.

The duration of acute kidney injury is an additional parameter to predict1-year survival in very elderly patients

Background:Acute kidney injury(AKI)is primarily defined and classified according to the magnitude of theelevation of serum creatinine(Scr).We aimed to determine whether the duration of AKI adds prognostic valuein addition to that obtained from the magnitude of injury alone.Methods:This retrospective study enrolled very elderly inpatients(≥75 years)in the Chinese PLA General Hospitalfrom January 2007 to December 2018.AKI was stratified by magnitude according to KDIGO stage(1,2,and 3)andduration(1–2 days,3–4 days,5–7 days,and>7 days).The primary outcome was the 1-year mortality after AKI.Multivariable Cox regression analysis was performed to identify covariates associated with the 1-year mortality.The probability of survival was estimated using the Kaplan–Meier method,and curves were compared using thelog-rank test.Results:In total,688 patients were enrolled,with the median age was 88(84–91)years,and the majority(652,94.8%)were male.According to the KDIGO criteria,317 patients(46.1%)had Stage 1 AKI,169(24.6%)hadStage 2 AKI,and 202(29.3%)had Stage 3 AKI.Of the 688 study subjects,61(8.9%)with a duration of AKIlasted 1–2 days,104(15.1%)with a duration of AKI lasted 3–4 days,140(20.3%)with a duration of AKI lasted5–7 days,and 383(55.7%)with a duration of AKI lasted>7 days.Within each stage,a longer duration of AKIwas slightly associated with a higher rate of 1-year mortality.However,within each of the duration categories,the stage of AKI was significantly associated with 1-year mortality.When considered separately in multivariateanalyses,both the duration of AKI(3–4 days:HR=3.184;95%CI:1.733–5.853;P<0.001,5–7 days:HR=1.915;95%CI:1.073–3.416;P=0.028;>7 days:HR=1.766;95%CI:1.017–3.065;P=0.043)and more advanced AKIstage(Stage 2:HR=3.063;95%CI:2.207–4.252;P<0.001;Stage 3:HR=7.333;95%CI:5.274–10.197;P<0.001)were independently associated with an increased risk of 1-year mortality.Conclusions:In very elderly AKI patients,both a higher stage and duration were independently associated withan increased risk of 1-year mortality.Hence,the duration of AKI adds additional information to predict long-termmortality.

纳米有机半导体光催化剂

近年来,有机半导体因其独特可调的化学结构及光电性质越来越多地被应用于高效可见光催化领域。但是,有机材料本身化学键弱、载流子迁移率低,导致其催化效率低、稳定性差。因此,将有机半导体进行纳米组装及其构建异质结构,得到零维、一维、二维或多元复合纳米有机光催化剂,成为近几年的研究热点。零维粒子尺寸小、比表面积大;一维结构长程有序排列、表面缺陷密度降低;二维结构在增大表面活性位点的同时能最大限度地缩短电荷在材料内部的迁移距离而表现出更高的光生电荷利用率;纳米复合结构的异质界面可以有效促进光生电子-空穴对的分离,因此在提高光催化活性及稳定性方面具有重要意义。同时,纳米有机光催化剂种类丰富,催化机理各不相同,因此被广泛应用于分解水或空气中污染物的光催化领域。本综述中归纳了各类纳米有机光催化剂的制备方法、结构特性以及光催化应用,同时对多种光催化机制进行了介绍,并对其应用前景进行了展望。

Influences of different Zr/Sc ratios on microstructure and mechanical properties of Al-2Si alloy

The influences of different Zr/Sc ratios on the microstructural evolution and mechanical performances of Al-2 Si alloy were investigated in this paper.The as-cast samples were characterized and analyzed by the scanning electron microscope(SEM)with an energy dispersive spectrometer(EDS)to indicate the refining effect of the different Zr/Sc ratios on theα-Al and Si phases in Al-2 Si alloy.The results indicate that theα-Al phases are refined from coarse dendritic structure to relatively fine equiaxed grains when the Zr/Sc ratio is equal to 1:1.Meanwhile,the eutectic Si phase in Al-2 Si-0.2 Zr-0.2 Sc alloy is modified from the coarse plate and needle to fine fiber and partial granular structure,and the average roundness of eutectic Si is decreased by 75%from 16 to 4.With the refinement ofα-Al phases and the modification of eutectic Si structure,the ultimate tensile strength(UTS)is improved by 53%and the elongation(EL)is increased by 64%when the Zr/Sc ratio is equal to 1:1.In addition,the UTS decreases and EL is enhanced with the increase of tensile temperature.Moreover,the fracture model of Al-2 Si-0.2 Zr-0.2 Sc alloy in250℃changes into the ductile fracture.

Effects of AlCoCrFeNiTi high-entropy alloy on microstructure and mechanical properties of pure aluminum

A new kind of AlCoCrFeNiTi high-entropy alloy(HEA)as a grain refiner was prepared by vacuum arc melting.In this work,the effects of HEA(1.0 wt.%,2.0 wt.%and 3.0 wt.%)on the microstructure and mechanical properties of pure aluminum were studied.The microstructure was characterized and examined by scanning electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD),electron probe micro-analyzer(EPMA)and transmission electron microscopy(TEM)to indicate the refining abilities and mechanism of HEA on pure aluminum.Results show that the addition of HEA refined both the macrostructure and microstructure of pure aluminum.When 1.0 wt.%HEA was added,most coarse columnar grains were refined into equiaxed crystals,and as the amount of HEA increased to 2.0 wt.%and3.0 wt.%,aluminum grains were further refined,and the grain boundaries were nearly indistinguishable.Moreover,the morphology ofα-Al transformed from coarse columnar crystals to equiaxed grains,and the mean size ofα-Al grains decreased from 374μm to 27μm.The Al3Ti,Al3Ni,and nano-phase precipitated from the aluminum alloy with HEA in the solidification.The typical rod-like nano-phases distributed interdendritic regions ofα-Al.The average length of nano-phases is 2568 nm,4372 nm,and 6907 nm and the average diameter is 112 nm,103 nm,and 92 nm when 1.0 wt.%,2.0 wt.%and 3.0 wt.%HEA were added to the pure aluminum,respectively.The ultimate tensile strength(UTS)and yield strength(YS)were improved in all samples,whereas the elongation(El)was decreased with increasing HEA concentration.When 3.0 wt.%HEA was added into the aluminum melt,the UTS was improved by 145.2%from62 MPa to 152 MPa,the YS was increased by 173.8%from 42 MPa to 115 MPa,and the El was decreased by 33.3%from 39%to 26%.

Contribution of plant traits to the explanation of temporal variations in carbon and water fluxes in semiarid grassland patches

准确预测异质性景观碳水通量的时空变化,对于综合理解气候变化和植被动态对景观和区域碳水循环的影响至关重要。本研究通过野外观测试验来探究草地斑块碳水通量的季节变化及其与非生物和生物因子之间的关系。在生长季通过密闭同化箱法测定了三个类型草地斑块的日间碳水通量(包括生态系统净交换、总生态系统生产力、生态系统呼吸和蒸散发),同时测定了关键植物性状指标,并计算性状加权平均值和功能分异度。研究结果表明,碳水通量的时间变化受气象因子、土壤因子和群落功能性状的影响。考虑植物功能性状加权平均值和功能分异度可以极大地提高景观尺度碳水通量变异的解释度。比叶面积和叶片δ^(13)C含量是影响气体通量变化的重要性状指标。群落加权平均值对碳通量的预测能力优于功能分异度,而功能分异度对蒸散发的解释度更高。我们的研究结果表明,生物量比假说和互补效应假说互不排斥,但两者对不同的生态系统过程的相对重要性不同,群落功能性状对半干旱草地碳水通量时空变化的机理解释和模型预测具有重要作用。

Early and minimal changes in serum creatinine can predict prognosis in elderly patients receiving invasive mechanical ventilation:A retrospective observational study

BackgroundEmerging evidence suggests that minimal acute kidney injury (stage 1 AKI) is associated with increased hospital mortality rates. However, for those who do not meet the AKI diagnostic criteria, whether a small increase in serum creatinine (SCr) levels is associated with an increased mortality rate in elderly patients is not known. Therefore, we aimed to investigate small elevations in SCr of <26.5 µmol/L within 48 h after invasive mechanical ventilation (MV) on the short-term mortality of critically ill patients in the geriatric population.MethodsWe conducted a retrospective, observational, multicenter cohort study enrolling consecutive elderly patients (≥75 years) who received invasive MV from January 2008 to December 2020. Recursive partitioning was used to calculate the ratio of SCr rise from baseline within 48 h after MV and divided into six groups, (1) <10%, (2) 10%–<20%, (3) 20%–<30%, (4) 30%–<40%, (5) 40%–<50%, and (6) ≥50%, where the reference interval was defined as the ratio <10% based on an analysis, which confirmed that the lowest mortality risk was found in this range. Clinical data and laboratory data were noted. Their general conditions and clinical characteristics were compared between the six groups. Prognostic survival factors were identified using Cox regression analysis. Kaplan–Meier survival analysis was employed for the accumulative survival rate.ResultsA total of 1292 patients (1171 men) with a median age of 89 (interquartile range: 85–92) with MV were suitable for further analysis. In all, 376 patients had any stage of early AKI, and 916 patients had no AKI. Among 916 non-AKI patients, 349 patients were in the ratio <10%, 291 in the 10%–<20% group, 169 in the 20%–<30% group, 68 in the 30%–<40% group, 25 in the 40%–<50% group, and 14 in the ≥50% group. The 28-day mortality rates in the six groups from the lowest (<10%) to the highest (≥50%) were 8.0%, 16.8%, 28.4%, 54.4%, 80.0%, and 85.7%, respectively. In the multivariable-adjusted analysis, patients with a ratio of 10%–<20% (hazard ratio [HR]=2.244;95% confidence interval [CI]: 1.410 to 3.572;P=0.001), 20%–<30% (HR=3.822;95% CI: 2.433 to 6.194;P <0.001), 30%–<40% (HR=10.472;95% CI: 6.379 to 17.190;P <0.001), 40%–<50% (HR=13.887;95% CI: 7.624 to 25.292;P <0.001), and ≥50% (HR=13.618;95% CI: 6.832 to 27.144;P <0.001) had relatively higher 28-day mortality rates. The 90-day mortality rates in the six strata were 30.1%, 35.1%, 45.0%, 60.3%, 80.0%, and 85.7%, respectively. Significant interactions were also observed between the ratio and 90-day mortality: patients with a ratio of 10%–<20% (HR=1.322;95% CI: 1.006 to 1.738;P=0.045), 20%–<30% (HR=1.823;95% CI: 1.356 to 2.452;P <0.001), 30%–<40% (HR=3.751;95% CI: 2.601 to 5.410;P <0.001), 40%–<50% (HR=5.735;95% CI: 3.447 to 9.541;P <0.001), and ≥50% (HR=6.305;95% CI: 3.430 to 11.588;P <0.001) had relatively higher 90-day mortality rates.ConclusionsOur study suggests that a ≥ 10% SCr rise from baseline within 48 h after MV was independently associated with short-term all-cause mortality in mechanically ventilated elderly patients.