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 biodiversit...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.展开更多
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 ...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.展开更多
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 injur...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.展开更多
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...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.展开更多
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 a...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.展开更多
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 ...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.展开更多
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 ...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.展开更多
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 addi...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.展开更多
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 scannin...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.展开更多
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 ...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%.展开更多
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 smal...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.展开更多
基金funded by the Asia-Pacific Network for Sustainable Forest Management and Rehabilitation(APFNet)(APFNET/2010/FPF/001)
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.31870967 to W.L.and 81701841 to W.B.W.)the National Key R&D Program of China(No.2018YFC1105800 to W.L.)。
文摘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.
基金financially supported by the National natural Science Foundation of China (Grant No.51761028)。
文摘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.
基金financially supported by the National Key Research and Development Program of China(2016YFB0700300)the National Natural Science Foundation of China(Grant No.51503014 and No.51501008)financial support from Fundamental Research Funds for the Central Universities(No.230201818-002A3).
文摘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.
基金the Special Scien-tific Research Project of Military Health Care(grant 20BJZ27 to FHZ),and the Military Medical。
文摘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.
基金funded by grants from the Special Scientific Research Project of Military Health Care(grant 20BJZ27 to FHZ)the Military Medical Innovation Project(grants 18CXZ026 and CX19010 to FHZ).
文摘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.
基金This study was funded by grants from the Special Scientific Research Project of Military Health Care(grant number:20BJZ27 to Dr FHZ)Special Scientific Research Project ofMilitary Key Laboratory of Military Medical Engineering(grantnumber:2022SYSZZKY12 to Dr FHZ).
文摘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.
基金Project supported by the National Natural Science Foundation of China(51561021),ChinaThe State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals+1 种基金Lanzhou University of Technology(SKLAB02019007),ChinaTraining Program on College Students of Gansu Province(DC2019161),China。
文摘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.
基金financially supported by the National Natural Science Foundation of China(No.51561021)the State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology(No.SKLAB02019007)the National Innovation Training Program of College Students of China(No.DC2019165 DC2019161)。
文摘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%.
基金supported by the National Key Research and Development Program of China(no.2016YFC0501602)International Partnership Program(no.121311KYSB20170004)of Chinese Academy of Sciences.
文摘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.