Objective:To explore the anti-aging effects of chlorogenic acid(CGA)and the underlying mechanisms based on a Caenorhabditis elegans(C.elegans)model.Methods:The anti-agingactivityofCGAwasstudied basedon thebodylength,e...Objective:To explore the anti-aging effects of chlorogenic acid(CGA)and the underlying mechanisms based on a Caenorhabditis elegans(C.elegans)model.Methods:The anti-agingactivityofCGAwasstudied basedon thebodylength,exercisebehavior,lipofuscin content,antioxidative stress ability,swallowing frequency,body-bending frequency,and head-swinging ability of C.elegans.Through DAF-16 nuclear translocation and SOD-3-GFP fluorescence experiments,the effects of CGA on ROS levels,antioxidant enzyme activities,MDA content,mutant-strain lifespan,and anti-aging molecular signaling pathways were explored,as well as the underlying mechanisms.Results:CGA improved multiple indices of the nematode:body length was increased(all P<0.001),head-swing frequency and body-bending frequency were increased(all P<0.05),nematode longevity was prolonged(P=0.0021),lipofuscin deposition in nematodes was slowed down(all P<0.001),the chemotaxis index was improved(P=0.0012),ROS levels were reduced(all P<.001),and SOD activity and MDA content were reduced(SOD:P=0.0017 between the low-concentration group and the control group,P<.001 between the high-concentration and medium-concentration groups and the control group;MDA:P=0.0135 between the low-concentration group and the control group,and P<0.001 between the high-concentration and medium-concentration groups and the control group).In addition,CGA also activated the DAF-16 transcription factor,promoted DAF-16 nuclear translocation under oxidative stress conditions(both P<0.001 between the high-concentration and medium-concentration groups and the control group),and increased SOD-3 gene expression in nematodes(all P<0.001).Conclusion:CGA plays an anti-aging role in C.elegans.The underlying mechanisms include activation of the insulin/IGF-1 signaling pathway and enhancement of DAF-16 activity.This study lays a foundation for further research into the anti-aging effects of CGA.展开更多
OBJECTIVE Behavior research and urinary metabolomics method were applied to evaluate the anti-aging effects of Scutellaria baicalensis Georgi extract(SBG)in D-galactose-induced rats.METHODS Fifty rats were randomly di...OBJECTIVE Behavior research and urinary metabolomics method were applied to evaluate the anti-aging effects of Scutellaria baicalensis Georgi extract(SBG)in D-galactose-induced rats.METHODS Fifty rats were randomly divided into five groups(n=10in each group).Group 1served as vehicle control with injection of saline(vehicle control group),and the other groups of rats received daily subcutaneously injected with D-galactose(aged model group)at dose of 100mg·kg-1 for ten weeks,respectively.At the same time,rats in groups 3-5were intragastrically administered SBG 〔extracted twice with 60%(V/V)ethanol〕at doses of 50,100 and 200mg·kg-1 for ten weeks,and the rats of groups 1 and 2 were administrated an equal volume of the vehicle.At the tenth week,the learning and memory abilities were examined by Morris water maze.The urine was collected using metabolic cages and analyzed by high-resolution 1HNMR spectroscopy combined with multivariate statistical analyses.Principal component analysis(PCA)was utilized to classify and reveal the differences between the model group and control group.Then,the concentration of these differences was analyzed with t-test to determine whether SBG was possible to influence the metabolic pattern induced by D-galactose.RESULTS Compared with the vehicle control group,the D-galactose-treated aged model group markedly spent longer time(P<0.05)in finding the platform on days 3-5 in the spatial learning acquisition training of Morris water maze test.However,the escape latency was significantly reduced(P<0.05)by long-term administration of SBG(50,100 and 200mg·kg-1)compared with the D-galactose-treated aged model group on days 3-5.In the probe test,the D-galactose-treated aged model group made fewer(P<0.05)platform crossings and distance travelled in target quadrant(P<0.05)than the vehicle control group,and the SBG at doses of 50,100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the number of times of crossing over the platform site.The SBG at doses of100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the distance travelled in target quadrant compared with the D-galactose-treated aged model group.In addition,the significant difference in metabolic profiling was observed from model group compared with drug-dose group by using PCA,indicating the recovery effect of SBG on D-galactose induced aging rats.Some significantly changed metabolites like glycine,glucose and hexadecanoic acid have been identified.These biochemical changes are related to the the disturbance in aimno acid metabolism,energy metabolism and glycometabolism,which are helpful to further understanding the D-galactose induced aging rats and the therapeutic mechanism of SBG.CONCLUSION These results demonstrate that SBG extract has protective effect on the D-galactose-induced aging in rats.展开更多
Aging and age-related ailments have emerged as critical challenges and great burdens within the global contemporary society.Addressing these concerns is an imperative task,with the aims of postponing the aging process...Aging and age-related ailments have emerged as critical challenges and great burdens within the global contemporary society.Addressing these concerns is an imperative task,with the aims of postponing the aging process and finding effective treatments for age-related degenerative diseases.Recent investigations have highlighted the significant roles of nicotinamide adenine dinucleotide(NAD+)in the realm of anti-aging.It has been empirically evidenced that supplementation with nicotinamide mononucleotide(NMN)can elevate NAD+levels in the body,thereby ameliorating certain age-related degenerative diseases.The principal anti-aging mechanisms of NMN essentially lie in its impact on cellular energy metabolism,inhibition of cell apoptosis,modulation of immune function,and preservation of genomic stability,which collectively contribute to the deferral of the aging process.This paper critically reviews and evaluates existing research on the anti-aging mechanisms of NMN,elucidates the inherent limitations of current research,and proposes novel avenues for anti-aging investigations.展开更多
The fruits of Paulownia catalpifolia Gong Tong are used as a Chinese folk herbal medicine for the treatment of enteritis, tonsillitis, bronchitis, and dysentery, etc. Our previous study has identified new C-geranylate...The fruits of Paulownia catalpifolia Gong Tong are used as a Chinese folk herbal medicine for the treatment of enteritis, tonsillitis, bronchitis, and dysentery, etc. Our previous study has identified new C-geranylated flavanones with obvious anti-proliferative effects in lung cancer A549 cells. In the present study, a new C-geranylated flavone, paucatalinone C(1) and five known C-geranylated flavanones(2-6) were isolated. In addition, a total of 34 C-geranylated flavonoids were detected by HPLC-DAD-ESI-MS/MS coupling techniques from the CH_2Cl_2 extract of P. catalpifolia. Futhermore, anti-aging effects of isolated compounds were evaluated in vitro with premature senescent 2BS cells induced by H_2O_2. Phytochemical results indicated that P. catalpifolia was a natural resource of abundant C-geranylated flavonoids. Diplacone(3) and paucatalinone A(5) were the potent anti-aging agents in the premature senescent 2BS cells induced by H_2O_2 and the C-geranyl substituent may be an important factor because of its lipophilic character.展开更多
BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations ...BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.展开更多
Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research ob...Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.展开更多
The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).Whil...The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.展开更多
The performance of Nb superconducting quantum devices is predominantly limited by dielectric loss at the metal–air interface,where Nb2O5 is considered the main loss source.Here,we suppress the formation of native oxi...The performance of Nb superconducting quantum devices is predominantly limited by dielectric loss at the metal–air interface,where Nb2O5 is considered the main loss source.Here,we suppress the formation of native oxides by in-situ deposition of a TiN capping layer on the Nb film.With TiN capping layers,no Nb2O5 forms on the surface of the Nb film.The quality factor Qi of the Nb resonator increases from 5.6×10^(5) to 7.9×10^(5) at low input power and from 6.8×10^(6) to 1.1×10^(7)at high input power.Furthermore,the TiN capping layer also shows good aging resistance in Nb resonator devices,with no significant performance fluctuations after one month of aging.These findings highlight the effectiveness of TiN capping layers in enhancing the performance and longevity of Nb superconducting quantum devices.展开更多
Boron is an ambitious fuel in energetic materials since its high heat release values,but its application is prohibited by low combustion efficiency and oxidization during storage.The polydopamine(PDA)was introduced in...Boron is an ambitious fuel in energetic materials since its high heat release values,but its application is prohibited by low combustion efficiency and oxidization during storage.The polydopamine(PDA)was introduced into boron particles,investigating the impact of PDA content on the energetic behavior of boron.The results indicated that the PDA coating formed a fishing net structure on the surface of boron particles.The heat release results showed that the combustion calorific value of B@PDA was higher than that of the raw boron.Specifically,the actual combustion heat of boron powder in B@10%PDA increased by 38.08%.Meanwhile,the DSC peak temperature decreased by 100.65℃under similar oxidation rate compared to raw boron.Simultaneously,the B@PDA@AP and B@AP composites were prepared,and their combustion properties were evaluated.It was demonstrated that B@10%PDA@AP exhibited superior performance in terms of peak pressure and burning time,respectively.The peak pressure is 12.43 kPa more than B@AP and burning time is 2.22 times higher than B@AP.Therefore,the coating of PDA effectively inhibits the oxidization of boron during storage and enhances the energetic behavior of boron and corresponding composites.展开更多
Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban...Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.展开更多
Climate change is the most significant threat to public health and exerts myriad influences on health,including the occurrence of extreme temperature events.Studies have demonstrated that populations will experience s...Climate change is the most significant threat to public health and exerts myriad influences on health,including the occurrence of extreme temperature events.Studies have demonstrated that populations will experience significantly severe cold waves in the future^([1]),increasing the risk of respiratory diseases.展开更多
Using micromagnetic simulations, we demonstrate the tilted perpendicular anisotropy-induced spin-orbit ratchet effect. In spin-orbit torque(SOT)-induced magnetization switching, the critical currents required to switc...Using micromagnetic simulations, we demonstrate the tilted perpendicular anisotropy-induced spin-orbit ratchet effect. In spin-orbit torque(SOT)-induced magnetization switching, the critical currents required to switch between the two magnetization states(upward and downward magnetization) are asymmetric. In addition, in the nanowire structure, tilted anisotropy induces formation of tilted domain walls(DWs). The tilted DWs exhibit a ratchet behavior during motion. The ratchet effect during switching and DW motions can be tuned by changing the current direction with respect to the tilting direction of anisotropy. The ratchet motion of the DWs can be used to mimic the leaky-integrate-fire function of a biological neuron, especially the asymmetric property of the “potential” and “reset” processes. Our results provide a full understanding of the influence of tilted perpendicular anisotropy on SOT-induced magnetization switching and DW motion, and are beneficial for designs of further SOT-based devices.展开更多
The present study investigates the effects of congruency and frequency on adjective-noun collocational processing for Chinese learners of English at two proficiency levels based on the data obtained in an online accep...The present study investigates the effects of congruency and frequency on adjective-noun collocational processing for Chinese learners of English at two proficiency levels based on the data obtained in an online acceptability judgment task.The subject pool of this research included 60 English majors studying at a university in China;30 were selected as a higher-proficiency group and 30 as a lower-proficiency group according to their Vocabulary Levels Test(Schmitt et al.,2001)scores and their self-reported proficiency in English.The experimental materials were programmed to E-prime 2.0 and included six types of collocations:(1)15 high-frequency congruent collocations,(2)15 low-frequency congruent collocations,(3)15 high-frequency incongruent collocations,(4)15 low-frequency incongruent collocations,(5)15 Chinese-only items,and(6)75 unrelated items for baseline data.The collected response times(RTs)and accuracy rates data were statistically analyzed by the use of an ANOVA test and pairwise comparisons through SPSS 16.0 software.The results revealed that:(1)the adjective-noun collocational processing of Chinese English learners is influenced by collocational frequency,congruency and L2 proficiency;(2)the processing time is affected by the interaction of congruency and frequency;and(3)the interactive effect of L2 proficiency in conjunction with congruency and frequency also influences the processing quality.展开更多
This socialized environment among educated and developed people causes themto focusmore on their appearance and health,which turns them towards medical-related treatments,leading us to discuss anti-aging treatment met...This socialized environment among educated and developed people causes themto focusmore on their appearance and health,which turns them towards medical-related treatments,leading us to discuss anti-aging treatment methods for each age group,particularly for urban people who are interested in this.Some anti-aging therapies are used to address the alterations brought on by aging in human life without the need for surgery or negative effects.Five anti-aging therapies such as microdermabrasion or dermabrasion,laser resurfacing anti-aging skin treatments,chemical peels,dermal fillers for aged skin,and botox injections are considered in this study.Based on the criteria of safety risk,investment cost,customer happiness,and side effects,the optimal alternative is picked.As a result,a NormalWiggly Hesitant Pythagorean Fuzzy Set(NWHPFS)is constructed and used in Multi-Criteria Decision-Making(MCDM)using traditional wavy mathematical approaches.The entropy approach is utilized to determine weight values,and the Normal Wiggly Hesitant Pythagorean-VlseKriterijumska Optimizacija I Kompromisno Resenje(NWHPF-VIKOR)method is utilized to rank alternatives using MCDM methodologies.Sensitivity analysis and comparative analysis were performed to ensure the robustness and reliability of the proposed method.The smart final choice will undoubtedly assist Decision Makers(DM)in making the right judgments,and the MCDM approach will undoubtedly assist individuals in understanding the medicine.展开更多
The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow movement.Consequently,they are widely used for protection against natural haza...The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow movement.Consequently,they are widely used for protection against natural hazards such as landslides and mudslides.This study,based on the threedimensional DEM(Discrete Element Method),investigated the impact of different baffle positions on debris flow protection.Debris flow velocity and kinetic energy variations were studied through single-factor experiments.Suitable baffle positions were preliminarily selected by analyzing the influence of the first-row baffle position on the impact force and accumulation mass of debris flow.Subsequently,based on the selected baffle positions and four factors influencing the effectiveness of baffle protection(baffle position(P),baffle height(h),row spacing(S_(r)),and angle of transit area(α)),an orthogonal design was employed to further explore the optimal arrangement of baffles.The research results indicate that the use of a baffle structure could effectively slow down the motion velocity of debris flows and dissipate their energy.When the baffle is placed in the transit area,the impact force on the first-row baffle is greater than that when the baffle is placed in the deposition area.Similarly,when the baffle is placed in the transit area,the obstruction effect on debris flow mass is also greater than that when the baffle is placed in the deposition area.Through orthogonal experimental range analysis,when the impact on the first row of baffles is used as the evaluation criterion,the importance of each influencing factor is ranked asα>P>S_(r)>h.When the mass of debris flow behind the baffle is regarded as the evaluation criterion,the rank is changed to P>α>S_(r)>h.The experimental simulation results show that the optimal baffle arrangement is:P_(5),S_(r)=16,α=35°,h=9.展开更多
Size effects are a well-documented phenomenon in heterogeneous catalysis,typically attributed to alterations in geometric and electronic properties.In this study,we investigate the influence of catalyst size in the pr...Size effects are a well-documented phenomenon in heterogeneous catalysis,typically attributed to alterations in geometric and electronic properties.In this study,we investigate the influence of catalyst size in the preparation of carbon nanotube(CNT)and the hydrogenation of 4,6-dinitroresorcinol(DNR)using Fe_(2)O_(3)and Pt catalysts,respectively.Various Fe_(2)O_(3)/Al_(2)O_(3)catalysts were synthesized for CNT growth through catalytic chemical vapor deposition.Our findings reveal a significant influence of Fe_(2)O_(3)nanoparticle size on the structure and yield of CNT.Specifically,CNT produced with Fe_(2)O_(3)/Al_(2)O_(3)containing 28%(mass)Fe loading exhibits abundant surface defects,an increased area for metal-particle immobilization,and a high carbon yield.This makes it a promising candidate for DNR hydrogenation.Utilizing this catalyst support,we further investigate the size effects of Pt nanoparticles on DNR hydrogenation.Larger Pt catalysts demonstrate a preference for 4,6-diaminoresorcinol generation at(100)sites,whereas smaller Pt catalysts are more susceptible to electronic properties.The kinetics insights obtained from this study have the potential to pave the way for the development of more efficient catalysts for both CNT synthesis and DNR hydrogenation.展开更多
Introduction: The greatest effect of maternal mortality is renowned in children aged 2 - 5 months whose mothers had died. Children whose mothers died due to maternal complications were likely to record a higher mortal...Introduction: The greatest effect of maternal mortality is renowned in children aged 2 - 5 months whose mothers had died. Children whose mothers died due to maternal complications were likely to record a higher mortality in infancy compared to children of surviving mothers. Motherless children mostly suffer a lot due to lack of day-to-day care, isolation, lack of motivation as well as economic cost associated with mother’s death. Thus, the purpose of this study was to ascertain the lives of children whose mothers passed away during childbirth at the Sagnarigu Municipality. Methods: This quantitative cross-sectional study was carried out at the Sagnarigu Municipal. The study recruited 297 respondents. To assess the effects of maternal death on the lives of children, families that experienced maternal death were assessed. The number of pregnancies experienced by the deceased woman, pregnancy-related complaints experienced, determinants of maternal death, number of children alive, and their standard of living were assessed with the aid of a structured questionnaire. Results: The data showed that negligence, illiteracy, poor road access, poverty, ignorance, delays in recognizing the problem, delays in making appropriate decisions, delays in the health facility, delays in giving the appropriate treatments, and traditional beliefs were some of the factors that led to maternal death in the Sagnarigu Municipality. Conclusion: The study concluded that determinants of maternal death in the Sagnarigu Municipal included the following;negligence, illiteracy, poverty, and delays in recognizing the problem. The study findings also demonstrated that the effects of maternal death on children are diverse and cut across different areas of a child’s life including livelihood sustenance, healthcare, education, and emotional and psychological development.展开更多
Theoretical studies of the diffusionalisotope effect in solids are still stuck in the 1960s and 1970s.With the development of high spatial resolution mass spectrometers,isotopic data of mineral grains are rapidly accu...Theoretical studies of the diffusionalisotope effect in solids are still stuck in the 1960s and 1970s.With the development of high spatial resolution mass spectrometers,isotopic data of mineral grains are rapidly accumulated.To dig up information from these data,molecularlevel theoretical models are urgently needed.Based on the microscopic definition of the diffusion coe fficient(D),a new theoretical framework for calculating the diffusional isotope effect(DIE(v))(intermsofD*/D)forvacancy-mediated impurity diffusion in solids is provided based on statistical mechanics formalism.The newly derived equation shows that theDIE(v)can be easily calculated as long as the vibration frequencies of isotope-substituted solids are obtained.The calculatedDIE(v)values of^(199)Au/^(195)Au and^(60)Co/^(57)Co during diffusion in Cu and Au metals are all within 1%of errors compared to the experimental data,which shows that this theoretical model is reasonable and precise.展开更多
Artificially controlling the solid-state precipitation in aluminum (Al) alloys is an efficient way to achieve well-performed properties,and the microalloying strategy is the most frequently adopted method for such a p...Artificially controlling the solid-state precipitation in aluminum (Al) alloys is an efficient way to achieve well-performed properties,and the microalloying strategy is the most frequently adopted method for such a purpose.In this paper,recent advances in lengthscale-dependent scandium (Sc) microalloying effects in Al-Cu model alloys are reviewed.In coarse-grained Al-Cu alloys,the Sc-aided Cu/Sc/vacancies complexes that act as heterogeneous nuclei and Sc segregation at the θ′-Al_(2)Cu/matrix interface that reduces interfacial energy contribute significantly to θ′precipitation.By grain size refinement to the fine/ultrafine-grained scale,the strongly bonded Cu/Sc/vacancies complexes inhibit Cu and vacancy diffusing toward grain boundaries,promoting the desired intragranular θ′precipitation.At nanocrystalline scale,the applied high strain producing high-density vacancies results in the formation of a large quantity of (Cu Sc,vacancy)-rich atomic complexes with high thermal stability,outstandingly improving the strength/ductility synergy and preventing the intractable low-temperature precipitation.This review recommends the use of microalloying technology to modify the precipitation behaviors toward better combined mechanical properties and thermal stability in Al alloys.展开更多
In riparian forests,litter decay provides essential energy and nutrients for both terrestrial and fluvial ecosystems.Litter mixing effects(LMEs)are crucial in regulating litter decay and nutrient dynamics,yet how LMEs...In riparian forests,litter decay provides essential energy and nutrients for both terrestrial and fluvial ecosystems.Litter mixing effects(LMEs)are crucial in regulating litter decay and nutrient dynamics,yet how LMEs change over time is unclear in riparian forests.In this study,leaf litter of three common species(Alnus sibirica Fisch.ex Turcz,Betula platyphylla Sukaczev,and Betula fruticosa Pall.)were mixed in an equal mass ratio and LMEs were measured for mass and nitrogen(N)remaining in whole litter mixtures over a 3-year period in a boreal riparian forest,northeastern China.LMEs were also assessed for component litter mass and N remaining by separating litter mixtures by species.During the decay of litter mixtures,antagonistic effects on mass and N remaining were dominant after one and two years of decay,whereas only additive effects were observed after three years.LMEs correlated negatively with functional diversity after the first and two years of decay but disappeared after three years.When sorting litter mixtures by species,non-additive LMEs on mass and N remaining decreased over incubation time.Moreover,non-additive LMEs were more frequent for litter of both B.platyphylla and B.fruticosa with lower N concentration than for A.sibirica litter with higher N concentration.These results indicate that incubation time is a key determinant of litter mixing effects during decay and highlight that late-stage litter mixture decay may be predicted from single litter decay dynamics in boreal riparian forests.展开更多
基金This study was supported by the Key Research Project Fund of Beijing University of Chinese Medicine(2021JYB2002001)the National Natural Science Foundation of Tibetan medicine Collabo-rative Innovation(82130113).
文摘Objective:To explore the anti-aging effects of chlorogenic acid(CGA)and the underlying mechanisms based on a Caenorhabditis elegans(C.elegans)model.Methods:The anti-agingactivityofCGAwasstudied basedon thebodylength,exercisebehavior,lipofuscin content,antioxidative stress ability,swallowing frequency,body-bending frequency,and head-swinging ability of C.elegans.Through DAF-16 nuclear translocation and SOD-3-GFP fluorescence experiments,the effects of CGA on ROS levels,antioxidant enzyme activities,MDA content,mutant-strain lifespan,and anti-aging molecular signaling pathways were explored,as well as the underlying mechanisms.Results:CGA improved multiple indices of the nematode:body length was increased(all P<0.001),head-swing frequency and body-bending frequency were increased(all P<0.05),nematode longevity was prolonged(P=0.0021),lipofuscin deposition in nematodes was slowed down(all P<0.001),the chemotaxis index was improved(P=0.0012),ROS levels were reduced(all P<.001),and SOD activity and MDA content were reduced(SOD:P=0.0017 between the low-concentration group and the control group,P<.001 between the high-concentration and medium-concentration groups and the control group;MDA:P=0.0135 between the low-concentration group and the control group,and P<0.001 between the high-concentration and medium-concentration groups and the control group).In addition,CGA also activated the DAF-16 transcription factor,promoted DAF-16 nuclear translocation under oxidative stress conditions(both P<0.001 between the high-concentration and medium-concentration groups and the control group),and increased SOD-3 gene expression in nematodes(all P<0.001).Conclusion:CGA plays an anti-aging role in C.elegans.The underlying mechanisms include activation of the insulin/IGF-1 signaling pathway and enhancement of DAF-16 activity.This study lays a foundation for further research into the anti-aging effects of CGA.
基金The project supported by the Construction Plan for Basic Condition Platform of Shanxi(2014091022)Program of Science and Technology of Shanxi Province(20140313008-14)
文摘OBJECTIVE Behavior research and urinary metabolomics method were applied to evaluate the anti-aging effects of Scutellaria baicalensis Georgi extract(SBG)in D-galactose-induced rats.METHODS Fifty rats were randomly divided into five groups(n=10in each group).Group 1served as vehicle control with injection of saline(vehicle control group),and the other groups of rats received daily subcutaneously injected with D-galactose(aged model group)at dose of 100mg·kg-1 for ten weeks,respectively.At the same time,rats in groups 3-5were intragastrically administered SBG 〔extracted twice with 60%(V/V)ethanol〕at doses of 50,100 and 200mg·kg-1 for ten weeks,and the rats of groups 1 and 2 were administrated an equal volume of the vehicle.At the tenth week,the learning and memory abilities were examined by Morris water maze.The urine was collected using metabolic cages and analyzed by high-resolution 1HNMR spectroscopy combined with multivariate statistical analyses.Principal component analysis(PCA)was utilized to classify and reveal the differences between the model group and control group.Then,the concentration of these differences was analyzed with t-test to determine whether SBG was possible to influence the metabolic pattern induced by D-galactose.RESULTS Compared with the vehicle control group,the D-galactose-treated aged model group markedly spent longer time(P<0.05)in finding the platform on days 3-5 in the spatial learning acquisition training of Morris water maze test.However,the escape latency was significantly reduced(P<0.05)by long-term administration of SBG(50,100 and 200mg·kg-1)compared with the D-galactose-treated aged model group on days 3-5.In the probe test,the D-galactose-treated aged model group made fewer(P<0.05)platform crossings and distance travelled in target quadrant(P<0.05)than the vehicle control group,and the SBG at doses of 50,100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the number of times of crossing over the platform site.The SBG at doses of100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the distance travelled in target quadrant compared with the D-galactose-treated aged model group.In addition,the significant difference in metabolic profiling was observed from model group compared with drug-dose group by using PCA,indicating the recovery effect of SBG on D-galactose induced aging rats.Some significantly changed metabolites like glycine,glucose and hexadecanoic acid have been identified.These biochemical changes are related to the the disturbance in aimno acid metabolism,energy metabolism and glycometabolism,which are helpful to further understanding the D-galactose induced aging rats and the therapeutic mechanism of SBG.CONCLUSION These results demonstrate that SBG extract has protective effect on the D-galactose-induced aging in rats.
文摘Aging and age-related ailments have emerged as critical challenges and great burdens within the global contemporary society.Addressing these concerns is an imperative task,with the aims of postponing the aging process and finding effective treatments for age-related degenerative diseases.Recent investigations have highlighted the significant roles of nicotinamide adenine dinucleotide(NAD+)in the realm of anti-aging.It has been empirically evidenced that supplementation with nicotinamide mononucleotide(NMN)can elevate NAD+levels in the body,thereby ameliorating certain age-related degenerative diseases.The principal anti-aging mechanisms of NMN essentially lie in its impact on cellular energy metabolism,inhibition of cell apoptosis,modulation of immune function,and preservation of genomic stability,which collectively contribute to the deferral of the aging process.This paper critically reviews and evaluates existing research on the anti-aging mechanisms of NMN,elucidates the inherent limitations of current research,and proposes novel avenues for anti-aging investigations.
基金financially supported by the Natural Science Foundation of Shandong Academy of Medical Sciences(No.2015-08)the Innovation Project of Shandong Academy of Medical Sciences and the Natural Science Open Foundation of State Key Laboratory of Bioactive Substance and Function of Natural Medicines(No.GTZK201503)
文摘The fruits of Paulownia catalpifolia Gong Tong are used as a Chinese folk herbal medicine for the treatment of enteritis, tonsillitis, bronchitis, and dysentery, etc. Our previous study has identified new C-geranylated flavanones with obvious anti-proliferative effects in lung cancer A549 cells. In the present study, a new C-geranylated flavone, paucatalinone C(1) and five known C-geranylated flavanones(2-6) were isolated. In addition, a total of 34 C-geranylated flavonoids were detected by HPLC-DAD-ESI-MS/MS coupling techniques from the CH_2Cl_2 extract of P. catalpifolia. Futhermore, anti-aging effects of isolated compounds were evaluated in vitro with premature senescent 2BS cells induced by H_2O_2. Phytochemical results indicated that P. catalpifolia was a natural resource of abundant C-geranylated flavonoids. Diplacone(3) and paucatalinone A(5) were the potent anti-aging agents in the premature senescent 2BS cells induced by H_2O_2 and the C-geranyl substituent may be an important factor because of its lipophilic character.
基金National Natural Science Foundation of China,No.72101236China Postdoctoral Science Foundation,No.2022M722900+1 种基金Collaborative Innovation Project of Zhengzhou City,No.XTCX2023006Nursing Team Project of the First Affiliated Hospital of Zhengzhou University,No.HLKY2023005.
文摘BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.
基金Under the auspices of National Natural Science Foundation of China(No.42171230)。
文摘Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.
基金jointly supported by the National Key Research and Development Program of China(Grant No.2022YFE0106500)Jiangsu Science Fund for Distinguished Young Scholars(Grant No.BK20200040)。
文摘The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.
基金the National Natural Science Foun-dation of China(Grant Nos.12034018 and 11625419).
文摘The performance of Nb superconducting quantum devices is predominantly limited by dielectric loss at the metal–air interface,where Nb2O5 is considered the main loss source.Here,we suppress the formation of native oxides by in-situ deposition of a TiN capping layer on the Nb film.With TiN capping layers,no Nb2O5 forms on the surface of the Nb film.The quality factor Qi of the Nb resonator increases from 5.6×10^(5) to 7.9×10^(5) at low input power and from 6.8×10^(6) to 1.1×10^(7)at high input power.Furthermore,the TiN capping layer also shows good aging resistance in Nb resonator devices,with no significant performance fluctuations after one month of aging.These findings highlight the effectiveness of TiN capping layers in enhancing the performance and longevity of Nb superconducting quantum devices.
文摘Boron is an ambitious fuel in energetic materials since its high heat release values,but its application is prohibited by low combustion efficiency and oxidization during storage.The polydopamine(PDA)was introduced into boron particles,investigating the impact of PDA content on the energetic behavior of boron.The results indicated that the PDA coating formed a fishing net structure on the surface of boron particles.The heat release results showed that the combustion calorific value of B@PDA was higher than that of the raw boron.Specifically,the actual combustion heat of boron powder in B@10%PDA increased by 38.08%.Meanwhile,the DSC peak temperature decreased by 100.65℃under similar oxidation rate compared to raw boron.Simultaneously,the B@PDA@AP and B@AP composites were prepared,and their combustion properties were evaluated.It was demonstrated that B@10%PDA@AP exhibited superior performance in terms of peak pressure and burning time,respectively.The peak pressure is 12.43 kPa more than B@AP and burning time is 2.22 times higher than B@AP.Therefore,the coating of PDA effectively inhibits the oxidization of boron during storage and enhances the energetic behavior of boron and corresponding composites.
基金the Youth Growth Technology Project,Science and Technology Department of Jilin Province(20230508130RC)Bureau of Forestry and Landscaping of Changchun.
文摘Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.
基金supported by the National Natural Science Foundation of China[Grant Nos.42375177,41975141]Natural Science Foundation of Gansu[Grant No.23JRRA1079]Fundamental Research Funds for the Central Universities[number:lzujbky-2023-it29].
文摘Climate change is the most significant threat to public health and exerts myriad influences on health,including the occurrence of extreme temperature events.Studies have demonstrated that populations will experience significantly severe cold waves in the future^([1]),increasing the risk of respiratory diseases.
基金supported by the National Natural Science Foundation of China (Grant No.12274108)the Natural Science Foundation of Zhejiang Province (Grant Nos.LY23A040008 and LY23A040008)the Basic Scientific Research Project of Wenzhou (Grant No.G20220025)。
文摘Using micromagnetic simulations, we demonstrate the tilted perpendicular anisotropy-induced spin-orbit ratchet effect. In spin-orbit torque(SOT)-induced magnetization switching, the critical currents required to switch between the two magnetization states(upward and downward magnetization) are asymmetric. In addition, in the nanowire structure, tilted anisotropy induces formation of tilted domain walls(DWs). The tilted DWs exhibit a ratchet behavior during motion. The ratchet effect during switching and DW motions can be tuned by changing the current direction with respect to the tilting direction of anisotropy. The ratchet motion of the DWs can be used to mimic the leaky-integrate-fire function of a biological neuron, especially the asymmetric property of the “potential” and “reset” processes. Our results provide a full understanding of the influence of tilted perpendicular anisotropy on SOT-induced magnetization switching and DW motion, and are beneficial for designs of further SOT-based devices.
文摘The present study investigates the effects of congruency and frequency on adjective-noun collocational processing for Chinese learners of English at two proficiency levels based on the data obtained in an online acceptability judgment task.The subject pool of this research included 60 English majors studying at a university in China;30 were selected as a higher-proficiency group and 30 as a lower-proficiency group according to their Vocabulary Levels Test(Schmitt et al.,2001)scores and their self-reported proficiency in English.The experimental materials were programmed to E-prime 2.0 and included six types of collocations:(1)15 high-frequency congruent collocations,(2)15 low-frequency congruent collocations,(3)15 high-frequency incongruent collocations,(4)15 low-frequency incongruent collocations,(5)15 Chinese-only items,and(6)75 unrelated items for baseline data.The collected response times(RTs)and accuracy rates data were statistically analyzed by the use of an ANOVA test and pairwise comparisons through SPSS 16.0 software.The results revealed that:(1)the adjective-noun collocational processing of Chinese English learners is influenced by collocational frequency,congruency and L2 proficiency;(2)the processing time is affected by the interaction of congruency and frequency;and(3)the interactive effect of L2 proficiency in conjunction with congruency and frequency also influences the processing quality.
基金funded by the Korean Government(MSIT)Grant NRF-2022R1C1C1006671.
文摘This socialized environment among educated and developed people causes themto focusmore on their appearance and health,which turns them towards medical-related treatments,leading us to discuss anti-aging treatment methods for each age group,particularly for urban people who are interested in this.Some anti-aging therapies are used to address the alterations brought on by aging in human life without the need for surgery or negative effects.Five anti-aging therapies such as microdermabrasion or dermabrasion,laser resurfacing anti-aging skin treatments,chemical peels,dermal fillers for aged skin,and botox injections are considered in this study.Based on the criteria of safety risk,investment cost,customer happiness,and side effects,the optimal alternative is picked.As a result,a NormalWiggly Hesitant Pythagorean Fuzzy Set(NWHPFS)is constructed and used in Multi-Criteria Decision-Making(MCDM)using traditional wavy mathematical approaches.The entropy approach is utilized to determine weight values,and the Normal Wiggly Hesitant Pythagorean-VlseKriterijumska Optimizacija I Kompromisno Resenje(NWHPF-VIKOR)method is utilized to rank alternatives using MCDM methodologies.Sensitivity analysis and comparative analysis were performed to ensure the robustness and reliability of the proposed method.The smart final choice will undoubtedly assist Decision Makers(DM)in making the right judgments,and the MCDM approach will undoubtedly assist individuals in understanding the medicine.
基金provided by the National Natural Science Foundation of China(Grant No.41977233)the key projects of the Science and Technology Department of Sichuan Province(Grant No.2020YJ0360)+1 种基金Sichuan Education and Teaching Reform project(Grant No.JG2021-1069)the opening project of Sichuan province university key Laboratory(Grant No.SC_FQWLY-2020-Z-02)。
文摘The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow movement.Consequently,they are widely used for protection against natural hazards such as landslides and mudslides.This study,based on the threedimensional DEM(Discrete Element Method),investigated the impact of different baffle positions on debris flow protection.Debris flow velocity and kinetic energy variations were studied through single-factor experiments.Suitable baffle positions were preliminarily selected by analyzing the influence of the first-row baffle position on the impact force and accumulation mass of debris flow.Subsequently,based on the selected baffle positions and four factors influencing the effectiveness of baffle protection(baffle position(P),baffle height(h),row spacing(S_(r)),and angle of transit area(α)),an orthogonal design was employed to further explore the optimal arrangement of baffles.The research results indicate that the use of a baffle structure could effectively slow down the motion velocity of debris flows and dissipate their energy.When the baffle is placed in the transit area,the impact force on the first-row baffle is greater than that when the baffle is placed in the deposition area.Similarly,when the baffle is placed in the transit area,the obstruction effect on debris flow mass is also greater than that when the baffle is placed in the deposition area.Through orthogonal experimental range analysis,when the impact on the first row of baffles is used as the evaluation criterion,the importance of each influencing factor is ranked asα>P>S_(r)>h.When the mass of debris flow behind the baffle is regarded as the evaluation criterion,the rank is changed to P>α>S_(r)>h.The experimental simulation results show that the optimal baffle arrangement is:P_(5),S_(r)=16,α=35°,h=9.
基金financially supported by the National Key Research and Development Program of China(2022YFA1503504)the National Natural Science Foundation of China(22038003,22178100,22178101,and U22B20141)+3 种基金the Shanghai Pilot Program for Basic Research(22TQ1400100-15)the Innovation Program of Shanghai Municipal Education Commissionthe Program of Shanghai Academic/Technology Research Leader(21XD1421000)the Shanghai Science and Technology Innovation Action Plan(22JC1403800)。
文摘Size effects are a well-documented phenomenon in heterogeneous catalysis,typically attributed to alterations in geometric and electronic properties.In this study,we investigate the influence of catalyst size in the preparation of carbon nanotube(CNT)and the hydrogenation of 4,6-dinitroresorcinol(DNR)using Fe_(2)O_(3)and Pt catalysts,respectively.Various Fe_(2)O_(3)/Al_(2)O_(3)catalysts were synthesized for CNT growth through catalytic chemical vapor deposition.Our findings reveal a significant influence of Fe_(2)O_(3)nanoparticle size on the structure and yield of CNT.Specifically,CNT produced with Fe_(2)O_(3)/Al_(2)O_(3)containing 28%(mass)Fe loading exhibits abundant surface defects,an increased area for metal-particle immobilization,and a high carbon yield.This makes it a promising candidate for DNR hydrogenation.Utilizing this catalyst support,we further investigate the size effects of Pt nanoparticles on DNR hydrogenation.Larger Pt catalysts demonstrate a preference for 4,6-diaminoresorcinol generation at(100)sites,whereas smaller Pt catalysts are more susceptible to electronic properties.The kinetics insights obtained from this study have the potential to pave the way for the development of more efficient catalysts for both CNT synthesis and DNR hydrogenation.
文摘Introduction: The greatest effect of maternal mortality is renowned in children aged 2 - 5 months whose mothers had died. Children whose mothers died due to maternal complications were likely to record a higher mortality in infancy compared to children of surviving mothers. Motherless children mostly suffer a lot due to lack of day-to-day care, isolation, lack of motivation as well as economic cost associated with mother’s death. Thus, the purpose of this study was to ascertain the lives of children whose mothers passed away during childbirth at the Sagnarigu Municipality. Methods: This quantitative cross-sectional study was carried out at the Sagnarigu Municipal. The study recruited 297 respondents. To assess the effects of maternal death on the lives of children, families that experienced maternal death were assessed. The number of pregnancies experienced by the deceased woman, pregnancy-related complaints experienced, determinants of maternal death, number of children alive, and their standard of living were assessed with the aid of a structured questionnaire. Results: The data showed that negligence, illiteracy, poor road access, poverty, ignorance, delays in recognizing the problem, delays in making appropriate decisions, delays in the health facility, delays in giving the appropriate treatments, and traditional beliefs were some of the factors that led to maternal death in the Sagnarigu Municipality. Conclusion: The study concluded that determinants of maternal death in the Sagnarigu Municipal included the following;negligence, illiteracy, poverty, and delays in recognizing the problem. The study findings also demonstrated that the effects of maternal death on children are diverse and cut across different areas of a child’s life including livelihood sustenance, healthcare, education, and emotional and psychological development.
基金suppor ted by Chinese NSF projects(42173021,41873024,42130114)the strategic priority research program(B)of CAS(XDB41000000)+1 种基金the preresearch Project on Civil Aerospace Technologies No.D020202 funded by the Chinese National Space Administration(CNSA)Guizhou Provincial 2021 Science and Technology Subsidies(No.GZ2021SIG)。
文摘Theoretical studies of the diffusionalisotope effect in solids are still stuck in the 1960s and 1970s.With the development of high spatial resolution mass spectrometers,isotopic data of mineral grains are rapidly accumulated.To dig up information from these data,molecularlevel theoretical models are urgently needed.Based on the microscopic definition of the diffusion coe fficient(D),a new theoretical framework for calculating the diffusional isotope effect(DIE(v))(intermsofD*/D)forvacancy-mediated impurity diffusion in solids is provided based on statistical mechanics formalism.The newly derived equation shows that theDIE(v)can be easily calculated as long as the vibration frequencies of isotope-substituted solids are obtained.The calculatedDIE(v)values of^(199)Au/^(195)Au and^(60)Co/^(57)Co during diffusion in Cu and Au metals are all within 1%of errors compared to the experimental data,which shows that this theoretical model is reasonable and precise.
基金supported by the National Natural Science Foundation of China(Nos.52201135,52271115,U23A6013,92360301,and U2330203)the 111 Project of China(No.BP2018008)+1 种基金the Shaanxi Province Innovation Team Project,China(No.2024RS-CXTD-58)supported by the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies and by the open research fund of Suzhou Laboratory。
文摘Artificially controlling the solid-state precipitation in aluminum (Al) alloys is an efficient way to achieve well-performed properties,and the microalloying strategy is the most frequently adopted method for such a purpose.In this paper,recent advances in lengthscale-dependent scandium (Sc) microalloying effects in Al-Cu model alloys are reviewed.In coarse-grained Al-Cu alloys,the Sc-aided Cu/Sc/vacancies complexes that act as heterogeneous nuclei and Sc segregation at the θ′-Al_(2)Cu/matrix interface that reduces interfacial energy contribute significantly to θ′precipitation.By grain size refinement to the fine/ultrafine-grained scale,the strongly bonded Cu/Sc/vacancies complexes inhibit Cu and vacancy diffusing toward grain boundaries,promoting the desired intragranular θ′precipitation.At nanocrystalline scale,the applied high strain producing high-density vacancies results in the formation of a large quantity of (Cu Sc,vacancy)-rich atomic complexes with high thermal stability,outstandingly improving the strength/ductility synergy and preventing the intractable low-temperature precipitation.This review recommends the use of microalloying technology to modify the precipitation behaviors toward better combined mechanical properties and thermal stability in Al alloys.
基金National Natural Science Foundation of China(41771108 and 31570479)the Natural Science Foundation of Jiangxi,China(20212ACB215002
文摘In riparian forests,litter decay provides essential energy and nutrients for both terrestrial and fluvial ecosystems.Litter mixing effects(LMEs)are crucial in regulating litter decay and nutrient dynamics,yet how LMEs change over time is unclear in riparian forests.In this study,leaf litter of three common species(Alnus sibirica Fisch.ex Turcz,Betula platyphylla Sukaczev,and Betula fruticosa Pall.)were mixed in an equal mass ratio and LMEs were measured for mass and nitrogen(N)remaining in whole litter mixtures over a 3-year period in a boreal riparian forest,northeastern China.LMEs were also assessed for component litter mass and N remaining by separating litter mixtures by species.During the decay of litter mixtures,antagonistic effects on mass and N remaining were dominant after one and two years of decay,whereas only additive effects were observed after three years.LMEs correlated negatively with functional diversity after the first and two years of decay but disappeared after three years.When sorting litter mixtures by species,non-additive LMEs on mass and N remaining decreased over incubation time.Moreover,non-additive LMEs were more frequent for litter of both B.platyphylla and B.fruticosa with lower N concentration than for A.sibirica litter with higher N concentration.These results indicate that incubation time is a key determinant of litter mixing effects during decay and highlight that late-stage litter mixture decay may be predicted from single litter decay dynamics in boreal riparian forests.