Background:Scientific animal models are indispensable for studying trauma repair.This work aimed at establishing a more scientific rat trauma model by studying different rat trauma models caused by different trauma nu...Background:Scientific animal models are indispensable for studying trauma repair.This work aimed at establishing a more scientific rat trauma model by studying different rat trauma models caused by different trauma numbers,locations,and trauma attachment tension unloaders and rat age.Methods:A four-trauma self-upper,lower,left and right control model;a two-trauma self-trauma bare and ring control model;and a young and old rat trauma model were created to evaluate the condition of these traumas.Results:In the four-trauma self-control model,the healing status of the upper proximal cephalic trauma was better than that of the lower proximal caudal trauma,whereas there was no significant difference between the left and right trauma.The healing rate and postwound condition of the trauma with a ring control in the two-trauma model were better than those of the bare side.The healing speed of the old rats was slower,and the amount of extracellular matrix in the subcutaneous tissue after healing was significantly lower than that of the young rats.Conclusion:The double trauma with a ring is a more scientific and reasonable experimental model.There is a significant difference between young and old rats in the wound healing process.Therefore,the appropriate age of the rats should be selected according to the main age range of the patients with similar conditions in the clinical setting being mimicked.展开更多
A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,t...A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,the aging rates between two age groups are set to be constant.The existence-and-uniqueness of global positive solution is firstly showed.Then,by constructing several appropriate Lyapunov functions and using the high-dimensional Itô’s formula,the sufficient conditions for the stochastic extinction and stochastic persistence of the exposed individuals and the infected individuals are obtained.The stochastic extinction indicator and the stochastic persistence indicator are less-valued expressions compared with the basic reproduction number.Meanwhile,the main results of this study are modified into multi-age groups.Furthermore,by using the surveillance data for Fujian Provincial Center for Disease Control and Prevention,Fuzhou COVID-19 epidemic is chosen to carry out the numerical simulations,which show that the age group of the population plays the vital role when studying infectious diseases.展开更多
The present study aims to establish a relationship between serum AMH levels and age in a large group of women living in Bulgaria, as well as to establish reference age-specific AMH levels in women that would serve as ...The present study aims to establish a relationship between serum AMH levels and age in a large group of women living in Bulgaria, as well as to establish reference age-specific AMH levels in women that would serve as an initial estimate of ovarian age. A total of 28,016 women on the territory of the Republic of Bulgaria were tested for serum AMH levels with a median age of 37.0 years (interquartile range 32.0 to 41.0). For women aged 20 - 29 years, the Bulgarian population has relatively high median levels of AMH, similar to women of Asian origin. For women aged 30 - 34 years, our results are comparable to those of women living in Western Europe. For women aged 35 - 39 years, our results are comparable to those of women living in the territory of India and Kenya. For women aged 40 - 44 years, our results were lower than those for women from the Western European and Chinese populations, close to the Indian and higher than Korean and Kenya populations, respectively. Our results for women of Bulgarian origin are also comparable to US Latina women at age 30, 35 and 40 ages. On the base on constructed a statistical model to predicting the decline in AMH levels at different ages, we found non-linear structure of AMH decline for the low AMH 3.5) the dependence of the decline of AMH on age was confirmed as linear. In conclusion, we evaluated the serum level of AMH in Bulgarian women and established age-specific AMH percentile reference values based on a large representative sample. We have developed a prognostic statistical model that can facilitate the application of AMH in clinical practice and the prediction of reproductive capacity and population health.展开更多
Mathematical models have been widely employed for the simulation of growth dynamics of annual crops,thereby performing yield prediction,but not for fruit tree species such as jujube tree(Zizyphus jujuba).The objective...Mathematical models have been widely employed for the simulation of growth dynamics of annual crops,thereby performing yield prediction,but not for fruit tree species such as jujube tree(Zizyphus jujuba).The objectives of this study were to investigate the potential use of a modified WOFOST model for predicting jujube yield by introducing tree age as a key parameter.The model was established using data collected from dedicated field experiments performed in 2016-2018.Simulated growth dynamics of dry weights of leaves,stems,fruits,total biomass and leaf area index(LAI) agreed well with measured values,showing root mean square error(RMSE) values of 0.143,0.333,0.366,0.624 t ha^-1 and 0.19,and R2 values of 0.947,0.976,0.985,0.986 and 0.95,respectively.Simulated phenological development stages for emergence,anthesis and maturity were 2,3 and 3 days earlier than the observed values,respectively.In addition,in order to predict the yields of trees with different ages,the weight of new organs(initial buds and roots) in each growing season was introduced as the initial total dry weight(TDWI),which was calculated as averaged,fitted and optimized values of trees with the same age.The results showed the evolution of the simulated LAI and yields profiled in response to the changes in TDWI.The modelling performance was significantly improved when it considered TDWI integrated with tree age,showing good global(R2≥0.856,RMSE≤0.68 t ha^-1) and local accuracies(mean R2≥0.43,RMSE≤0.70 t ha^-1).Furthermore,the optimized TDWI exhibited the highest precision,with globally validated R2 of 0.891 and RMSE of 0.591 t ha^-1,and local mean R2 of 0.57 and RMSE of 0.66 t ha^-1,respectively.The proposed model was not only verified with the confidence to accurately predict yields of jujube,but it can also provide a fundamental strategy for simulating the growth of other fruit trees.展开更多
Plantations of Rupprecht's larch(Larix principis-rupprechtii)have been widely established in the drylands of northwest and north China under traditional fastgrowing plantation management strategies.These strategie...Plantations of Rupprecht's larch(Larix principis-rupprechtii)have been widely established in the drylands of northwest and north China under traditional fastgrowing plantation management strategies.These strategies and the long-term logging ban have led to over-populated stands with lower structural and functional stability,less economic benefit and higher water consumption.To guide the sustainable management of larch plantations,field surveys and historical data compilation were undertaken in the Liupan Mountains of northwest China.The main influencing factors(stand structure and site condition)and their effects on mean tree height,mean DBH and timber volumes were determined based on up-boundary line analysis.Tree growth models coupling the effects of tree age,stand density,and elevation were established.Both height and DBH markedly increased initially and then slowly with tree age,decreased with stand density,and showed unimodal change with elevation.The coupled growth models accounted for72-78%of the variations in tree height,DBH and timber growth.Recommendations for future plantation management are:(1)prolong the rotation to at least 60 years to produce large-diameter,high-quality timber and maintain greater carbon stocks;(2)zone the target functions of stands by elevation;and,(3)reduce stand density for balanced supply of multiple ecosystem services.The growth models developed can predict growth response of larch plantations to density alteration under given ages and elevations,and assist the transformation from traditional management for maximum timber production to site-specific and multifunctional management with longer rotations and moderate tree density.展开更多
A reliable chronology is essentially critical for correlating loess records with other paleoenvironmental time series, as well as for continuing improvements in the reconstruction of paleoenvironment and paleoclimate ...A reliable chronology is essentially critical for correlating loess records with other paleoenvironmental time series, as well as for continuing improvements in the reconstruction of paleoenvironment and paleoclimate changes. It is exactly that the scarcity of chronologies across the Sea of Azov has limited the interpretation of climatic and environmental information in the East European Plain. In view of this, this paper conducted an exploratory study to investigate whether the optically stimulated luminescence(OSL) dating of medium-grained quartz could be used to obtain a set of chronologies and the age models could be used to establish an independent time scale since the Late Pleistocene for the Sea of Azov loess. The results showed that an internally consistent set of optical ages for the Azov loess deposited up to ~76 ka. In addition, the ages developed based on magnetic susceptibility and grain size ages models showed good comparability with independent OSL ages at an acceptable range, suggesting that it might be practicable to establish an independent time scale using age models at the Sea of Azov loess, at least for the uppermost part of the Chumbur-Kosa section. Comparison with the ages based on two age models,the grain size ages using fine-grain fractions may provide a more reliable chronological sequence at the Azov loess since the Late Pleistocene. With the help of absolute ages and climate proxies(magnetic susceptibility and grain size), paleoclimatic change in the Sea of Azov have been traced for the Late Pleistocene.展开更多
We present a first-order finite difference scheme for approximating solutions of a mathematical model of cervical cancer induced by the human papillomavirus (HPV), which consists of four nonlinear partial differential...We present a first-order finite difference scheme for approximating solutions of a mathematical model of cervical cancer induced by the human papillomavirus (HPV), which consists of four nonlinear partial differential equations and a nonlinear first-order ordinary differential equation. The scheme is analyzed and used to provide an existence-uniqueness result. Numerical simulations are performed in order to demonstrate the first-order rate of convergence. A sensitivity analysis was done in order to compare the effects of two drug types, those that increase the death rate of HPV-infected cells, and those that increase the death rate of the precancerous cell population. The model predicts that treatments that affect the precancerous cell population by directly increasing the corresponding death rate are far more effective than those that increase the death rate of HPV-infected cells.展开更多
A great discovery made by H. von Foerster, P. M. Mora and L. W. Amiot was published in a 1960 issue of “Science”. The authors showed that existing data for calculating the Earth’s population in the new era (from 1 ...A great discovery made by H. von Foerster, P. M. Mora and L. W. Amiot was published in a 1960 issue of “Science”. The authors showed that existing data for calculating the Earth’s population in the new era (from 1 to 1958) could be described with incredibly high proximity by a hyperbolic function with the point of singularity on 13 November 2026. Thus, empirical regularity of the rise of the human population was established, which was marked by explosive demographic growth in the 20<sup>th</sup> century when during only one century it almost quadrupled: from 1.656 billion in 1900 to 6.144 billion in 2000. Nowadays, the world population has already overcome 7.8 billion people. Immediately after 1960, an active search for phenomenological models began to explain the mechanism of the hyperbolic population growth and the following demographic transition designed to stabilize its population. A significant role in explaining the mechanism of the hyperbolic growth of the world population was played by S. Kuznets (1960) and E. Boserup (1965), who found out that the rates of technological progress historically increased in proportion to the Earth’s population. It meant that the growth of the population led to raising the level of life-supporting technologies, and the latter in its turn enlarged the carrying capacity of the Earth, making it possible for the world population to expand. Proceeding from the information imperative, we have developed the model of the demographic dynamics for the 21<sup>st</sup> century for the first time. The model shows that with the development and spread of Intelligent Machines (IM), the number of the world population reaching a certain maximum will then irreversibly decline. Human depopulation will largely touch upon the most developed countries, where IM is used intensively nowadays. Until a certain moment in time, this depopulation in developed countries will be compensated by the explosive growth of the population in African countries located south of the Sahara. Calculations in our model reveal that the peak of the human population of 8.52 billion people will be reached in 2050, then it will irreversibly go down to 7.9 billion people by 2100, if developed countries do not take timely effective measures to overcome the process of information depopulation.展开更多
Neodymium (Nd) depleted mantle model ages indicate that the Kangding complexes in the northern segment of the western Yangtze craton, argued as representative of the craton's basement, actually formed after 1.6 Ga...Neodymium (Nd) depleted mantle model ages indicate that the Kangding complexes in the northern segment of the western Yangtze craton, argued as representative of the craton's basement, actually formed after 1.6 Ga. An Sm-Nd isochron of 706 Ma constrains the upper limit formation of the complex from Shaba, Sichuan Province. Lead (Pb) isotopic compositions imply that the southern and northern basements of the western Yangtze craton can not be correlated. The southern basement is characterized by higher ~206Pb/~204Pb ratios (≥17.69) than the northern ones (<17.69). However, Hercynian granitoids, gabbros as well as the Permian basalts in the northern segment show no difference from the southern segment in Pb isotopic compositions. This suggests that the southern and northern segments were controlled by one common mantle domain during the Late Paleozoic. Based on Nd model ages of sediments and metasediments, as well as the ages of their relict zircons, we infer that the Yangtze craton is mainly composed of 2.0 Ga crustal components. The Kangding complex represents the accretion products to the Yangtze craton in Neoproterozoic.展开更多
The Tieshanlong ore field is an important part of the Nanling Range,which is famous worldwide for its W-Sn mineralization.Notably,the mineralization age of the Tieshanlong ore field is not well constrained,and our fie...The Tieshanlong ore field is an important part of the Nanling Range,which is famous worldwide for its W-Sn mineralization.Notably,the mineralization age of the Tieshanlong ore field is not well constrained,and our field investigation reveals that granitic emplacement occurred at different stages.However,previous studies have not distinguished these multiple stages of magmatism.The Tieshanlong granite complex is closely related to the Huangsha quartz vein-type W-Sn deposit and Tongling skarn-type Cu-W-Sn deposit in this field.Through field investigations and isotopic age analyses,this work studies the relationship between multistage magmatic activity and mineralization in the Tieshanlong ore field.LA-ICP-MS zircon U-Pb isotope analyses revealed that the first-and second-staged granites formed at 154.2±0.6 Ma(MSDW=1.4)and 151.2±0.4 Ma(MSDW=1.5),with zirconε_(Hf)(t)values ranging from-13.1 to-10.5 and from-14.7 to-11.1,respectively.These data suggest that the Tieshanlong granite complex was derived from the partial melting of ancient crustal material.LA-ICP-MS U-Pb dating of wolframite and cassiterite reveals that W-Sn mineralization occurred at 160-150 Ma,which agrees well with the U-Pb dating results of the second-staged granite within analytical errors.The magmatic activity in this ore field can be divided into three stages:175-154 Ma,154-150 Ma and 150-145 Ma.The quartz vein-and skarn-type W-Sn mineralization is closely related to second-staged fine-grained twomica granite,and formed earlier than skarn-type Cu-mineralization.This study establishes a metallogenic model for the Tieshanlong ore field,and this model has important practical significance for identifying concealed W-Sn(-Cu)deposits around other granitic complexes in the Nanling Range.展开更多
A unified constitutive model is presented to predict the recently observed“multi-stage”creep behavior of Al−Li−S4 alloy.The corresponding microstructural variables related to the yield strength and creep deformation...A unified constitutive model is presented to predict the recently observed“multi-stage”creep behavior of Al−Li−S4 alloy.The corresponding microstructural variables related to the yield strength and creep deformation of the alloy during the creep ageing process,including dislocations and multiple precipitates,have been characterized in detail by X-ray diffraction(XRD)and transmission electron microscopy(TEM).For the yield strength,the model considers the multiphase strengthening behavior of the alloy based on strengthening mechanisms,which includes shearable T1 precipitate strengthening,non-shearable T1 precipitate strengthening andθ′precipitate strengthening.Based on creep deformation mechanism,the“multi-stage”creep behavior of the alloy is predicted by introducing the effects of interacting microstructural variables,including the radius of multiple precipitates,dislocation density and solute concentration,into the creep stress−strain model.It is concluded that the results calculated by the model are in a good agreement with the experimental data,which validates the proposed model.展开更多
The Hongqiling large nickel-copper-cobalt deposit(hereafter referred to as the Hongqiling deposit),a typical mafic-ultramafic copper-nickel deposit in China,boasts proven Ni(Ni)resources of approximately 22×10^(4...The Hongqiling large nickel-copper-cobalt deposit(hereafter referred to as the Hongqiling deposit),a typical mafic-ultramafic copper-nickel deposit in China,boasts proven Ni(Ni)resources of approximately 22×10^(4)t,associated copper resources of 2×10^(4)t,and associated cobalt(Co)resources of 0.5×10^(4)t,with Ni reserves ranking 10th among China's magmatic nickel deposits.Geotectonically,the Hongqiling deposit is situated in the superimposed zone between the Xing'an-Mongolian orogenic belt and the circum-Western Pacific's active continental margin belt.Its ore-bearing plutons occur within the metamorphic rocks of the Ordovician Hulan Group,with the emplacement of plutons and the locations of orebodies governed by the deep-seated Huifahe fault and its secondary NW-trending Fujia-Hejiagou-Beixinglong-Changsheng fault zone.In the deposit,the rock assemblages of ore-bearing plutons predominantly encompass gabbro-pyroxenite-olivine pyroxenite-pyroxene peridotite(pluton No.1)and norite-orthopyroxenite-harzburgite(pluton No.7),with ore-bearing lithofacies consisting primarily of olivine pyroxenite and pyroxenite facies.The Hongqiling deposit hosts stratoid,overhanging lentoid,veined,and pure-sulfide veined orebodies.Its ores principally contain metallic minerals including pyrrhotite,pentlandite,chalcopyrite,violarite,and pyrite.Despite unidentified magma sources of ore-bearing mafic-ultramafic rocks,it is roughly accepted that the magmatic evolution in the Hongqiling deposit primarily involved fractional crystallization and crustal contamination.The ore-forming materials were primarily derived from the upper mantle,mixed with minor crustal materials.The ore-bearing mafic-ultramafic rocks in the deposit,primarily emplaced during the Indosinian(208-239 Ma),were formed in an intense extension setting followed by the collisional orogeny between the North China Plate and the Songnen-Zhangguangcai Range Block during the Middle-Late Triassic.From the perspective of the metallogenic geological setting,surrounding rocks,ore-controlling structures,and rock assemblages,this study identified one favorable condition and seven significant indicators for prospecting for Hongqiling-type nickel deposits and developed a prospecting model of the Hongqiling deposit.These serve as valuable references for exploring similar nickel deposits in the region,as well as the deep parts and margins of the Hongqiling deposit.展开更多
Based on approaches deduced from previous research findings and empirical observations from density control experiments, genetic worth effect response models were developed for black spruce (Picea mariana (Mill) BSP.)...Based on approaches deduced from previous research findings and empirical observations from density control experiments, genetic worth effect response models were developed for black spruce (Picea mariana (Mill) BSP.) and jack pine (Pinus banksiana Lamb.) plantations. The models accounted for the increased rate of stand development arising from the planting of genetically-improved stock through temporal adjustments to the species-specific site-based mean dominant height-age functions. The models utilized a relative height growth modifier based on known estimates of genetic gain. The models also incorporated a phenotypic juvenile age-mature age correlation function in order to account for the intrinsic temporal decline in the magnitude of genetic worth effects throughout the rotation. Integrating the functions into algorithmic variants of structural stand density management models produced stand development patterns that were consistent with axioms of even-aged stand dynamics.展开更多
As a multi-branch estuary system, the Yangtze Estuary presents distinctive characteristics of hydrodynamic processes through co-action among river runoff, tides, wind-waves, and gravitational circulation. To study the...As a multi-branch estuary system, the Yangtze Estuary presents distinctive characteristics of hydrodynamic processes through co-action among river runoff, tides, wind-waves, and gravitational circulation. To study the pathways of flushing water along all of the estuary's branches and analyze their differences, especially those due to the influence of seawater intrusion and discharge variations, a free surface flow modeling suite TELEMAC-MASCARET involving passive tracers was applied to the Yangtze Estuary and the adjacent waters. The open boundary conditions were provided by the Nao.99 b model(Matsumoto et al., 2000), which was calibrated using observed velocity and salinity data obtained in March 2002. The water age, which was used as the diagnostic tool to study the flushing efficiency of the water body across the estuary, was solved by additional advection-diffusion-reaction equations implemented in the TELEMAC modeling system. The transport properties were investigated under different river discharge scenarios, which represented seasonal impacts; aspects relating to the influence of tide, surface wind stress, and density-induced circulation on age were also investigated. Model results showed that river runoff is one of the dominant factors influencing the spatial distribution of the mean age, while tidal force is another important factor. The horizontal freshwater age distribution demonstrated similarity compared with the salinity distribution; the vertical age distribution resembled the stratification pattern of salinity in all branches where stratification persists. An experimental numerical simulation of tracing saltwater age from the lower reaches of the estuary was conducted, and implicated the connectivity with transport processes of freshwater from upstream. Additionally, a particle tracking algorithm was used to analyze the dynamic characteristics of the four passages. The South Passage and South Channel were found to be significant as main water flow passages, while salinity intrusion in the North Branch was found to cause a return flow that partially joins the South Branch flushing water.展开更多
BACKGROUND： Animal models of brachial plexus root avulsion are required for the study of brachial plexus root injuries. The established ventral approach results in slight injuries, and is similar to mechanisms underl...BACKGROUND： Animal models of brachial plexus root avulsion are required for the study of brachial plexus root injuries. The established ventral approach results in slight injuries, and is similar to mechanisms underlying human brachial plexus root avulsion.OBJECTIVE： To analyze the effects of weight, age, and species on the success rate of brachial plexus root avulsion, and to determine the perfect method for establishing models of brachial plexus root avulsion.DESIGN, TIME AND SETTING： A randomized, block design was performed at the Laboratory of Professor Lihua Zhou, Zhongshan School of Medicine, Sun Yat-sen University, China from June 2008 to June 2009.MATERIALS： Sprague Dawley （SD） rats, golden hamsters, and BALb/C mice were used in the present study.METHODS： All animals were randomly subjected to classical brachial plexus root avulsion and modified brachial plexus root avulsion.MAIN OUTCOME MEASURES： Success rate of brachial plexus root avulsion. RESULTS： The success rate of brachial plexus root avulsion was greater in the modified group than in the classical group （P〈0.01）. Moreover, the difference was significant in 15-day-old SD rats, 5-week-old SD rats, and 3-month-old BALb/C mice （P〈0.01）. The success rate of brachial plexus root avulsion was greater in the same weight, 15-day-old juvenile SD rats, than in the 3-month-old BALb/C mice （classical group, P〈0.01; modified group, P〈0.05）. The success rate of brachial plexus root avulsion was significantly greater in 3-month-old golden hamsters than in 5-week-old SD rats in the classical group （P〈0.05）. The success rate of brachial plexus root avulsion was significantly lower in the 15-day-old SD rats compared with the 5-week-old and 3-month-old SD rats in the classical group （P〈0.01）. However, there was no significant difference in the success rate of brachial plexus root avulsion between various ages of SD rats in the modified group （P〉0.05）.CONCLUSION： Modified surgery to induce brachial plexus root avulsion significantly increases the success rate of model establishment. Species, age, and weight affect the success rate of brachial plexus root avulsion, and species plays an important role in the success rate.展开更多
Despite the advances in combinatorial or synthetic chemis- try and bioinformatics, recent literature has demonstrated the relevance of nature and biomass as a source of new molecules to treat different pathologies, i....Despite the advances in combinatorial or synthetic chemis- try and bioinformatics, recent literature has demonstrated the relevance of nature and biomass as a source of new molecules to treat different pathologies, i.e., bioactive com- pounds obtained from Ecteinascidia turbinate to treat some types of cancer or rapamycin from Streptomyces hygroscop- icus to prevent organ rejection after transplant. This trend will continue simply due to the fact that Mother Nature has been synthesizing molecules for millions of years. In our lab- oratory, we have characterized several compounds obtained from natural sources and that possess important neuronal effects,展开更多
Attention to the pension work is the performance of social development and progress, effective selection of effective old-age way to promote the elderly in his later years and it is the inevitable requirement of the d...Attention to the pension work is the performance of social development and progress, effective selection of effective old-age way to promote the elderly in his later years and it is the inevitable requirement of the development of the times. On the basis of comparative analysis of the pros and cons of various pension methods, the actual social work department must carry out specific judgment on the specificold people. The elderly need not only the material aspects of life care, but also the need for emotional support and spiritual comfort, in the new historical conditions must be in the body and mind and informed lines and other aspects of the elderly to give loved ones, considerate, warm and friendly , respect and care. This paper proposes the novel perspective on the planning model of Chinese aged community in background of European and American old-age system. In the future, we will apply the proposed model into more scenarios to test the performance.展开更多
Advanced Glycation End-Products (AGEs), play a crucial part in advancing the process of cellular skin aging and its link to chronological age was re-assessed. AGEs accumulation alters cell structure and function of mo...Advanced Glycation End-Products (AGEs), play a crucial part in advancing the process of cellular skin aging and its link to chronological age was re-assessed. AGEs accumulation alters cell structure and function of most types of skin cells, affecting skin’s mechanical and physiological properties, following the molecular transformations. Slowdown AGEs accumulation rate in skin, although a potent anti-aging strategy, is difficult and tricky. The lack of working methods for <span style="white-space:nowrap;"><i>In-Vitro</i></span> and <span style="white-space:nowrap;"><i>In-Vitro</i></span> measuring AGEs level complicates the evaluation and prediction of active ingredients’ ability to affect cellular AGEs accumulation. A two-step <span style="white-space:nowrap;"><i>In-Vitro</i></span> systematic screening method is proposed and three different cosmetic active ingredients were selected for its demonstration, using BSA-Glucose and Collagen-Glucose predicting models. Candidates’ effects on AGEs accumulation were evaluated as standalone, and when formulated in a blend. Additionally, the potency of non-invasive auto-fluorescence in-vivo measurement to detect AGEs levels among subjects of different ages was demonstrated. The results are presented in this work and the potential contribution of the proposed system to assist the desired inhibition of AGEs accumulation in skin is discussed.展开更多
The constitutive modeling and springback simulation for AA2524 sheet in creep age forming（CAF） process were presented.A series of creep aging tests were performed on AA2524 at the temperature of 180-200 °C and ...The constitutive modeling and springback simulation for AA2524 sheet in creep age forming（CAF） process were presented.A series of creep aging tests were performed on AA2524 at the temperature of 180-200 °C and under the stress of 140-210 MPa for 16 h.Based on these experimental data,material constitutive equations which can well characterize creep aging behaviors of the tested alloy were developed.The effect of interior stress distributed along the sheet thickness on springback was simulated using FE software MSC.MARC by compiling the established constitutive models into the user subroutine.The simulation results showed that the amount of sheet springback was 61.12% when merely considering tensile stress existing along the sheet thickness;while sheet springback was up to 65.93% when taking both tensile and compressive stresses into account.In addition,an AA2524 rectangular sheet was subjected to CAF experiment in resistance furnace.The springback value of the formed rectangular sheet was 68.2%,which was much closer to 65.93%.This confirms that both tensile and compressive stresses across the sheet thickness should be considered in accurately predicting springback of the sheet after forming,which can be more consistent with experimental results.展开更多
基金Shandong Provincial Natural Science Foundation,Grant/Award Number:ZR2022MH211the Key Program of Shandong Provincial Natural Science Foundation,Grant/Award Number:ZR2020KE018National Natural Science Foundation of China,Grant/Award Number:52003068。
文摘Background:Scientific animal models are indispensable for studying trauma repair.This work aimed at establishing a more scientific rat trauma model by studying different rat trauma models caused by different trauma numbers,locations,and trauma attachment tension unloaders and rat age.Methods:A four-trauma self-upper,lower,left and right control model;a two-trauma self-trauma bare and ring control model;and a young and old rat trauma model were created to evaluate the condition of these traumas.Results:In the four-trauma self-control model,the healing status of the upper proximal cephalic trauma was better than that of the lower proximal caudal trauma,whereas there was no significant difference between the left and right trauma.The healing rate and postwound condition of the trauma with a ring control in the two-trauma model were better than those of the bare side.The healing speed of the old rats was slower,and the amount of extracellular matrix in the subcutaneous tissue after healing was significantly lower than that of the young rats.Conclusion:The double trauma with a ring is a more scientific and reasonable experimental model.There is a significant difference between young and old rats in the wound healing process.Therefore,the appropriate age of the rats should be selected according to the main age range of the patients with similar conditions in the clinical setting being mimicked.
基金Supported by National Natural Science Foundation of China(61911530398,12231012)Consultancy Project by the Chinese Academy of Engineering(2022-JB-06,2023-JB-12)+3 种基金the Natural Science Foundation of Fujian Province of China(2021J01621)Special Projects of the Central Government Guiding Local Science and Technology Development(2021L3018)Royal Society of Edinburgh(RSE1832)Engineering and Physical Sciences Research Council(EP/W522521/1).
文摘A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,the aging rates between two age groups are set to be constant.The existence-and-uniqueness of global positive solution is firstly showed.Then,by constructing several appropriate Lyapunov functions and using the high-dimensional Itô’s formula,the sufficient conditions for the stochastic extinction and stochastic persistence of the exposed individuals and the infected individuals are obtained.The stochastic extinction indicator and the stochastic persistence indicator are less-valued expressions compared with the basic reproduction number.Meanwhile,the main results of this study are modified into multi-age groups.Furthermore,by using the surveillance data for Fujian Provincial Center for Disease Control and Prevention,Fuzhou COVID-19 epidemic is chosen to carry out the numerical simulations,which show that the age group of the population plays the vital role when studying infectious diseases.
文摘The present study aims to establish a relationship between serum AMH levels and age in a large group of women living in Bulgaria, as well as to establish reference age-specific AMH levels in women that would serve as an initial estimate of ovarian age. A total of 28,016 women on the territory of the Republic of Bulgaria were tested for serum AMH levels with a median age of 37.0 years (interquartile range 32.0 to 41.0). For women aged 20 - 29 years, the Bulgarian population has relatively high median levels of AMH, similar to women of Asian origin. For women aged 30 - 34 years, our results are comparable to those of women living in Western Europe. For women aged 35 - 39 years, our results are comparable to those of women living in the territory of India and Kenya. For women aged 40 - 44 years, our results were lower than those for women from the Western European and Chinese populations, close to the Indian and higher than Korean and Kenya populations, respectively. Our results for women of Bulgarian origin are also comparable to US Latina women at age 30, 35 and 40 ages. On the base on constructed a statistical model to predicting the decline in AMH levels at different ages, we found non-linear structure of AMH decline for the low AMH 3.5) the dependence of the decline of AMH on age was confirmed as linear. In conclusion, we evaluated the serum level of AMH in Bulgarian women and established age-specific AMH percentile reference values based on a large representative sample. We have developed a prognostic statistical model that can facilitate the application of AMH in clinical practice and the prediction of reproductive capacity and population health.
基金supported by the National Natural Science Foundation of China(41561088 and 61501314)the Science&Technology Nova Program of Xinjiang Production and Construction Corps,China(2018CB020)
文摘Mathematical models have been widely employed for the simulation of growth dynamics of annual crops,thereby performing yield prediction,but not for fruit tree species such as jujube tree(Zizyphus jujuba).The objectives of this study were to investigate the potential use of a modified WOFOST model for predicting jujube yield by introducing tree age as a key parameter.The model was established using data collected from dedicated field experiments performed in 2016-2018.Simulated growth dynamics of dry weights of leaves,stems,fruits,total biomass and leaf area index(LAI) agreed well with measured values,showing root mean square error(RMSE) values of 0.143,0.333,0.366,0.624 t ha^-1 and 0.19,and R2 values of 0.947,0.976,0.985,0.986 and 0.95,respectively.Simulated phenological development stages for emergence,anthesis and maturity were 2,3 and 3 days earlier than the observed values,respectively.In addition,in order to predict the yields of trees with different ages,the weight of new organs(initial buds and roots) in each growing season was introduced as the initial total dry weight(TDWI),which was calculated as averaged,fitted and optimized values of trees with the same age.The results showed the evolution of the simulated LAI and yields profiled in response to the changes in TDWI.The modelling performance was significantly improved when it considered TDWI integrated with tree age,showing good global(R2≥0.856,RMSE≤0.68 t ha^-1) and local accuracies(mean R2≥0.43,RMSE≤0.70 t ha^-1).Furthermore,the optimized TDWI exhibited the highest precision,with globally validated R2 of 0.891 and RMSE of 0.591 t ha^-1,and local mean R2 of 0.57 and RMSE of 0.66 t ha^-1,respectively.The proposed model was not only verified with the confidence to accurately predict yields of jujube,but it can also provide a fundamental strategy for simulating the growth of other fruit trees.
基金funded by the National Natural Science Foundation of China (U20A2085,U21A2005,41971038)the Central Public-Interest Scientifi c Institution Basal Research Fund of Chinese Academy of Forestry (CAFYBB2021ZW002,CAFYBB2020QB004)。
文摘Plantations of Rupprecht's larch(Larix principis-rupprechtii)have been widely established in the drylands of northwest and north China under traditional fastgrowing plantation management strategies.These strategies and the long-term logging ban have led to over-populated stands with lower structural and functional stability,less economic benefit and higher water consumption.To guide the sustainable management of larch plantations,field surveys and historical data compilation were undertaken in the Liupan Mountains of northwest China.The main influencing factors(stand structure and site condition)and their effects on mean tree height,mean DBH and timber volumes were determined based on up-boundary line analysis.Tree growth models coupling the effects of tree age,stand density,and elevation were established.Both height and DBH markedly increased initially and then slowly with tree age,decreased with stand density,and showed unimodal change with elevation.The coupled growth models accounted for72-78%of the variations in tree height,DBH and timber growth.Recommendations for future plantation management are:(1)prolong the rotation to at least 60 years to produce large-diameter,high-quality timber and maintain greater carbon stocks;(2)zone the target functions of stands by elevation;and,(3)reduce stand density for balanced supply of multiple ecosystem services.The growth models developed can predict growth response of larch plantations to density alteration under given ages and elevations,and assist the transformation from traditional management for maximum timber production to site-specific and multifunctional management with longer rotations and moderate tree density.
基金auspices of the National Natural Science Foundation of China (Grant No. 41271024)the International Cooperation and Exchange Project (Grant No. 41411130204)the Fundamental Research Funds for the Central Universities (Grant No. lzujbky-2016-270)
文摘A reliable chronology is essentially critical for correlating loess records with other paleoenvironmental time series, as well as for continuing improvements in the reconstruction of paleoenvironment and paleoclimate changes. It is exactly that the scarcity of chronologies across the Sea of Azov has limited the interpretation of climatic and environmental information in the East European Plain. In view of this, this paper conducted an exploratory study to investigate whether the optically stimulated luminescence(OSL) dating of medium-grained quartz could be used to obtain a set of chronologies and the age models could be used to establish an independent time scale since the Late Pleistocene for the Sea of Azov loess. The results showed that an internally consistent set of optical ages for the Azov loess deposited up to ~76 ka. In addition, the ages developed based on magnetic susceptibility and grain size ages models showed good comparability with independent OSL ages at an acceptable range, suggesting that it might be practicable to establish an independent time scale using age models at the Sea of Azov loess, at least for the uppermost part of the Chumbur-Kosa section. Comparison with the ages based on two age models,the grain size ages using fine-grain fractions may provide a more reliable chronological sequence at the Azov loess since the Late Pleistocene. With the help of absolute ages and climate proxies(magnetic susceptibility and grain size), paleoclimatic change in the Sea of Azov have been traced for the Late Pleistocene.
文摘We present a first-order finite difference scheme for approximating solutions of a mathematical model of cervical cancer induced by the human papillomavirus (HPV), which consists of four nonlinear partial differential equations and a nonlinear first-order ordinary differential equation. The scheme is analyzed and used to provide an existence-uniqueness result. Numerical simulations are performed in order to demonstrate the first-order rate of convergence. A sensitivity analysis was done in order to compare the effects of two drug types, those that increase the death rate of HPV-infected cells, and those that increase the death rate of the precancerous cell population. The model predicts that treatments that affect the precancerous cell population by directly increasing the corresponding death rate are far more effective than those that increase the death rate of HPV-infected cells.
文摘A great discovery made by H. von Foerster, P. M. Mora and L. W. Amiot was published in a 1960 issue of “Science”. The authors showed that existing data for calculating the Earth’s population in the new era (from 1 to 1958) could be described with incredibly high proximity by a hyperbolic function with the point of singularity on 13 November 2026. Thus, empirical regularity of the rise of the human population was established, which was marked by explosive demographic growth in the 20<sup>th</sup> century when during only one century it almost quadrupled: from 1.656 billion in 1900 to 6.144 billion in 2000. Nowadays, the world population has already overcome 7.8 billion people. Immediately after 1960, an active search for phenomenological models began to explain the mechanism of the hyperbolic population growth and the following demographic transition designed to stabilize its population. A significant role in explaining the mechanism of the hyperbolic growth of the world population was played by S. Kuznets (1960) and E. Boserup (1965), who found out that the rates of technological progress historically increased in proportion to the Earth’s population. It meant that the growth of the population led to raising the level of life-supporting technologies, and the latter in its turn enlarged the carrying capacity of the Earth, making it possible for the world population to expand. Proceeding from the information imperative, we have developed the model of the demographic dynamics for the 21<sup>st</sup> century for the first time. The model shows that with the development and spread of Intelligent Machines (IM), the number of the world population reaching a certain maximum will then irreversibly decline. Human depopulation will largely touch upon the most developed countries, where IM is used intensively nowadays. Until a certain moment in time, this depopulation in developed countries will be compensated by the explosive growth of the population in African countries located south of the Sahara. Calculations in our model reveal that the peak of the human population of 8.52 billion people will be reached in 2050, then it will irreversibly go down to 7.9 billion people by 2100, if developed countries do not take timely effective measures to overcome the process of information depopulation.
文摘Neodymium (Nd) depleted mantle model ages indicate that the Kangding complexes in the northern segment of the western Yangtze craton, argued as representative of the craton's basement, actually formed after 1.6 Ga. An Sm-Nd isochron of 706 Ma constrains the upper limit formation of the complex from Shaba, Sichuan Province. Lead (Pb) isotopic compositions imply that the southern and northern basements of the western Yangtze craton can not be correlated. The southern basement is characterized by higher ~206Pb/~204Pb ratios (≥17.69) than the northern ones (<17.69). However, Hercynian granitoids, gabbros as well as the Permian basalts in the northern segment show no difference from the southern segment in Pb isotopic compositions. This suggests that the southern and northern segments were controlled by one common mantle domain during the Late Paleozoic. Based on Nd model ages of sediments and metasediments, as well as the ages of their relict zircons, we infer that the Yangtze craton is mainly composed of 2.0 Ga crustal components. The Kangding complex represents the accretion products to the Yangtze craton in Neoproterozoic.
基金supported by the Young Science and Technology Leader Training Plan Project of Jiangxi Bureau of Geology(Grant No.2024JXDZKJRC01)the Key Laboratory of Ionic Rare Earth Resources and Environment,Ministry of Natural Resources of the People's Republic of China(Grant No.2022IRERE101)+1 种基金the National Key R&D Program of China(Grant No.2020YFA0406400)the Jiangxi Geological Survey Project(Grant Nos.20210041 and 20242001)。
文摘The Tieshanlong ore field is an important part of the Nanling Range,which is famous worldwide for its W-Sn mineralization.Notably,the mineralization age of the Tieshanlong ore field is not well constrained,and our field investigation reveals that granitic emplacement occurred at different stages.However,previous studies have not distinguished these multiple stages of magmatism.The Tieshanlong granite complex is closely related to the Huangsha quartz vein-type W-Sn deposit and Tongling skarn-type Cu-W-Sn deposit in this field.Through field investigations and isotopic age analyses,this work studies the relationship between multistage magmatic activity and mineralization in the Tieshanlong ore field.LA-ICP-MS zircon U-Pb isotope analyses revealed that the first-and second-staged granites formed at 154.2±0.6 Ma(MSDW=1.4)and 151.2±0.4 Ma(MSDW=1.5),with zirconε_(Hf)(t)values ranging from-13.1 to-10.5 and from-14.7 to-11.1,respectively.These data suggest that the Tieshanlong granite complex was derived from the partial melting of ancient crustal material.LA-ICP-MS U-Pb dating of wolframite and cassiterite reveals that W-Sn mineralization occurred at 160-150 Ma,which agrees well with the U-Pb dating results of the second-staged granite within analytical errors.The magmatic activity in this ore field can be divided into three stages:175-154 Ma,154-150 Ma and 150-145 Ma.The quartz vein-and skarn-type W-Sn mineralization is closely related to second-staged fine-grained twomica granite,and formed earlier than skarn-type Cu-mineralization.This study establishes a metallogenic model for the Tieshanlong ore field,and this model has important practical significance for identifying concealed W-Sn(-Cu)deposits around other granitic complexes in the Nanling Range.
基金the National Key R&D Program of China(No.2017YFB0306300)the National Natural Science Foundation of China(Nos.51675538,51601060)+1 种基金the State Key Laboratory of High-performance Complex Manufacturing,China(No.ZZYJKT2018-18)the Fundamental Research Funds for the Central Universities of Central South University,China(No.2018zzts151).
文摘A unified constitutive model is presented to predict the recently observed“multi-stage”creep behavior of Al−Li−S4 alloy.The corresponding microstructural variables related to the yield strength and creep deformation of the alloy during the creep ageing process,including dislocations and multiple precipitates,have been characterized in detail by X-ray diffraction(XRD)and transmission electron microscopy(TEM).For the yield strength,the model considers the multiphase strengthening behavior of the alloy based on strengthening mechanisms,which includes shearable T1 precipitate strengthening,non-shearable T1 precipitate strengthening andθ′precipitate strengthening.Based on creep deformation mechanism,the“multi-stage”creep behavior of the alloy is predicted by introducing the effects of interacting microstructural variables,including the radius of multiple precipitates,dislocation density and solute concentration,into the creep stress−strain model.It is concluded that the results calculated by the model are in a good agreement with the experimental data,which validates the proposed model.
基金funded by projects of the China Geological Survey(Nos.DD20242070,DD20230763,DD20221695,DD20190379,and DD20160346)。
文摘The Hongqiling large nickel-copper-cobalt deposit(hereafter referred to as the Hongqiling deposit),a typical mafic-ultramafic copper-nickel deposit in China,boasts proven Ni(Ni)resources of approximately 22×10^(4)t,associated copper resources of 2×10^(4)t,and associated cobalt(Co)resources of 0.5×10^(4)t,with Ni reserves ranking 10th among China's magmatic nickel deposits.Geotectonically,the Hongqiling deposit is situated in the superimposed zone between the Xing'an-Mongolian orogenic belt and the circum-Western Pacific's active continental margin belt.Its ore-bearing plutons occur within the metamorphic rocks of the Ordovician Hulan Group,with the emplacement of plutons and the locations of orebodies governed by the deep-seated Huifahe fault and its secondary NW-trending Fujia-Hejiagou-Beixinglong-Changsheng fault zone.In the deposit,the rock assemblages of ore-bearing plutons predominantly encompass gabbro-pyroxenite-olivine pyroxenite-pyroxene peridotite(pluton No.1)and norite-orthopyroxenite-harzburgite(pluton No.7),with ore-bearing lithofacies consisting primarily of olivine pyroxenite and pyroxenite facies.The Hongqiling deposit hosts stratoid,overhanging lentoid,veined,and pure-sulfide veined orebodies.Its ores principally contain metallic minerals including pyrrhotite,pentlandite,chalcopyrite,violarite,and pyrite.Despite unidentified magma sources of ore-bearing mafic-ultramafic rocks,it is roughly accepted that the magmatic evolution in the Hongqiling deposit primarily involved fractional crystallization and crustal contamination.The ore-forming materials were primarily derived from the upper mantle,mixed with minor crustal materials.The ore-bearing mafic-ultramafic rocks in the deposit,primarily emplaced during the Indosinian(208-239 Ma),were formed in an intense extension setting followed by the collisional orogeny between the North China Plate and the Songnen-Zhangguangcai Range Block during the Middle-Late Triassic.From the perspective of the metallogenic geological setting,surrounding rocks,ore-controlling structures,and rock assemblages,this study identified one favorable condition and seven significant indicators for prospecting for Hongqiling-type nickel deposits and developed a prospecting model of the Hongqiling deposit.These serve as valuable references for exploring similar nickel deposits in the region,as well as the deep parts and margins of the Hongqiling deposit.
文摘Based on approaches deduced from previous research findings and empirical observations from density control experiments, genetic worth effect response models were developed for black spruce (Picea mariana (Mill) BSP.) and jack pine (Pinus banksiana Lamb.) plantations. The models accounted for the increased rate of stand development arising from the planting of genetically-improved stock through temporal adjustments to the species-specific site-based mean dominant height-age functions. The models utilized a relative height growth modifier based on known estimates of genetic gain. The models also incorporated a phenotypic juvenile age-mature age correlation function in order to account for the intrinsic temporal decline in the magnitude of genetic worth effects throughout the rotation. Integrating the functions into algorithmic variants of structural stand density management models produced stand development patterns that were consistent with axioms of even-aged stand dynamics.
基金supported by the National Natural Science Foundation of China (No. 51409093)
文摘As a multi-branch estuary system, the Yangtze Estuary presents distinctive characteristics of hydrodynamic processes through co-action among river runoff, tides, wind-waves, and gravitational circulation. To study the pathways of flushing water along all of the estuary's branches and analyze their differences, especially those due to the influence of seawater intrusion and discharge variations, a free surface flow modeling suite TELEMAC-MASCARET involving passive tracers was applied to the Yangtze Estuary and the adjacent waters. The open boundary conditions were provided by the Nao.99 b model(Matsumoto et al., 2000), which was calibrated using observed velocity and salinity data obtained in March 2002. The water age, which was used as the diagnostic tool to study the flushing efficiency of the water body across the estuary, was solved by additional advection-diffusion-reaction equations implemented in the TELEMAC modeling system. The transport properties were investigated under different river discharge scenarios, which represented seasonal impacts; aspects relating to the influence of tide, surface wind stress, and density-induced circulation on age were also investigated. Model results showed that river runoff is one of the dominant factors influencing the spatial distribution of the mean age, while tidal force is another important factor. The horizontal freshwater age distribution demonstrated similarity compared with the salinity distribution; the vertical age distribution resembled the stratification pattern of salinity in all branches where stratification persists. An experimental numerical simulation of tracing saltwater age from the lower reaches of the estuary was conducted, and implicated the connectivity with transport processes of freshwater from upstream. Additionally, a particle tracking algorithm was used to analyze the dynamic characteristics of the four passages. The South Passage and South Channel were found to be significant as main water flow passages, while salinity intrusion in the North Branch was found to cause a return flow that partially joins the South Branch flushing water.
基金a Grant from Health Department of Guangdong Province in China,No. A2007169
文摘BACKGROUND： Animal models of brachial plexus root avulsion are required for the study of brachial plexus root injuries. The established ventral approach results in slight injuries, and is similar to mechanisms underlying human brachial plexus root avulsion.OBJECTIVE： To analyze the effects of weight, age, and species on the success rate of brachial plexus root avulsion, and to determine the perfect method for establishing models of brachial plexus root avulsion.DESIGN, TIME AND SETTING： A randomized, block design was performed at the Laboratory of Professor Lihua Zhou, Zhongshan School of Medicine, Sun Yat-sen University, China from June 2008 to June 2009.MATERIALS： Sprague Dawley （SD） rats, golden hamsters, and BALb/C mice were used in the present study.METHODS： All animals were randomly subjected to classical brachial plexus root avulsion and modified brachial plexus root avulsion.MAIN OUTCOME MEASURES： Success rate of brachial plexus root avulsion. RESULTS： The success rate of brachial plexus root avulsion was greater in the modified group than in the classical group （P〈0.01）. Moreover, the difference was significant in 15-day-old SD rats, 5-week-old SD rats, and 3-month-old BALb/C mice （P〈0.01）. The success rate of brachial plexus root avulsion was greater in the same weight, 15-day-old juvenile SD rats, than in the 3-month-old BALb/C mice （classical group, P〈0.01; modified group, P〈0.05）. The success rate of brachial plexus root avulsion was significantly greater in 3-month-old golden hamsters than in 5-week-old SD rats in the classical group （P〈0.05）. The success rate of brachial plexus root avulsion was significantly lower in the 15-day-old SD rats compared with the 5-week-old and 3-month-old SD rats in the classical group （P〈0.01）. However, there was no significant difference in the success rate of brachial plexus root avulsion between various ages of SD rats in the modified group （P〉0.05）.CONCLUSION： Modified surgery to induce brachial plexus root avulsion significantly increases the success rate of model establishment. Species, age, and weight affect the success rate of brachial plexus root avulsion, and species plays an important role in the success rate.
文摘Despite the advances in combinatorial or synthetic chemis- try and bioinformatics, recent literature has demonstrated the relevance of nature and biomass as a source of new molecules to treat different pathologies, i.e., bioactive com- pounds obtained from Ecteinascidia turbinate to treat some types of cancer or rapamycin from Streptomyces hygroscop- icus to prevent organ rejection after transplant. This trend will continue simply due to the fact that Mother Nature has been synthesizing molecules for millions of years. In our lab- oratory, we have characterized several compounds obtained from natural sources and that possess important neuronal effects,
文摘Attention to the pension work is the performance of social development and progress, effective selection of effective old-age way to promote the elderly in his later years and it is the inevitable requirement of the development of the times. On the basis of comparative analysis of the pros and cons of various pension methods, the actual social work department must carry out specific judgment on the specificold people. The elderly need not only the material aspects of life care, but also the need for emotional support and spiritual comfort, in the new historical conditions must be in the body and mind and informed lines and other aspects of the elderly to give loved ones, considerate, warm and friendly , respect and care. This paper proposes the novel perspective on the planning model of Chinese aged community in background of European and American old-age system. In the future, we will apply the proposed model into more scenarios to test the performance.
文摘Advanced Glycation End-Products (AGEs), play a crucial part in advancing the process of cellular skin aging and its link to chronological age was re-assessed. AGEs accumulation alters cell structure and function of most types of skin cells, affecting skin’s mechanical and physiological properties, following the molecular transformations. Slowdown AGEs accumulation rate in skin, although a potent anti-aging strategy, is difficult and tricky. The lack of working methods for <span style="white-space:nowrap;"><i>In-Vitro</i></span> and <span style="white-space:nowrap;"><i>In-Vitro</i></span> measuring AGEs level complicates the evaluation and prediction of active ingredients’ ability to affect cellular AGEs accumulation. A two-step <span style="white-space:nowrap;"><i>In-Vitro</i></span> systematic screening method is proposed and three different cosmetic active ingredients were selected for its demonstration, using BSA-Glucose and Collagen-Glucose predicting models. Candidates’ effects on AGEs accumulation were evaluated as standalone, and when formulated in a blend. Additionally, the potency of non-invasive auto-fluorescence in-vivo measurement to detect AGEs levels among subjects of different ages was demonstrated. The results are presented in this work and the potential contribution of the proposed system to assist the desired inhibition of AGEs accumulation in skin is discussed.
基金Project(2014CB046602)supported by the National Basic Research Program of ChinaProject(20120162110003)supported by Ph D Programs Foundation of Ministry of Education of China
文摘The constitutive modeling and springback simulation for AA2524 sheet in creep age forming（CAF） process were presented.A series of creep aging tests were performed on AA2524 at the temperature of 180-200 °C and under the stress of 140-210 MPa for 16 h.Based on these experimental data,material constitutive equations which can well characterize creep aging behaviors of the tested alloy were developed.The effect of interior stress distributed along the sheet thickness on springback was simulated using FE software MSC.MARC by compiling the established constitutive models into the user subroutine.The simulation results showed that the amount of sheet springback was 61.12% when merely considering tensile stress existing along the sheet thickness;while sheet springback was up to 65.93% when taking both tensile and compressive stresses into account.In addition,an AA2524 rectangular sheet was subjected to CAF experiment in resistance furnace.The springback value of the formed rectangular sheet was 68.2%,which was much closer to 65.93%.This confirms that both tensile and compressive stresses across the sheet thickness should be considered in accurately predicting springback of the sheet after forming,which can be more consistent with experimental results.
