Downregulation of Serum PTEN Expression in Mercury-Exposed Population and PI3K/AKT Pathway-Induced Inflammation

Objective This study investigated the impact of occupational mercury(Hg) exposure on human gene transcription and expression, and its potential biological mechanisms.Methods Differentially expressed genes related to Hg exposure were identified and validated using gene expression microarray analysis and extended validation. Hg-exposed cell models and PTEN lowexpression models were established in vitro using 293T cells. PTEN gene expression was assessed using qRT-PCR, and Western blotting was used to measure PTEN, AKT, and PI3K protein levels. IL-6 expression was determined by ELISA.Results Combined findings from gene expression microarray analysis, bioinformatics, and population expansion validation indicated significant downregulation of the PTEN gene in the high-concentration Hg exposure group. In the Hg-exposed cell model(25 and 10 μmol/L), a significant decrease in PTEN expression was observed, accompanied by a significant increase in PI3K, AKT, and IL-6 expression.Similarly, a low-expression cell model demonstrated that PTEN gene knockdown led to a significant decrease in PTEN protein expression and a substantial increase in PI3K, AKT, and IL-6 levels.Conclusion This is the first study to report that Hg exposure downregulates the PTEN gene, activates the PI3K/AKT regulatory pathway, and increases the expression of inflammatory factors, ultimately resulting in kidney inflammation.

Mercury Levels Assessment in the Population of Aby and Frambo Villages in the Vinicity of Aby Lagoon in Côte d’Ivoire (West Africa)

The Minamata Convention in the aim to protect human life and the environment, seeks to reduce mercury (Hg) by monitoring it concentrations in the environment. Artisanal and Small-scale Gold Mining (ASGM) has been identified as the most important anthropogenic source of human exposure to Hg. In this context, the main goal of this study was to assess the level of mercury in hair of two (2) populations living along two lagoons respectively Aby and Tendo, in Ivory Coast. To reach this goal, hair samples of 138 residents were collected and analyzed by using Cold Vapor Atomic Fluorescence Spectrophotometry (CV-AFS) technique for mercury concentration. Results showed that for the entire population the Hg mean was 2.34 μg/g. Also, they were ranged between 0.15 to 8.53 μg/g and presented substantial differences amongst the villages. In Aby village, we observed the highest Hg concentrations (Mean = 2.62 μg/g). Our findings showed that almost the entire sample group (82%) exceed the USEPA recommended limit, furthermore 56% of them exceed the normal level of WHO and 2% of the respondent has the unhealthy levels of mercury (≥6 μg Hg/g) of hair by WHO standards. Gender differences in hair mercury varies greatly among reports. Lower levels in women’s hair compared to men were reported in the both village. Considering age, the lowest concentrations were observed with children. However, when we take in account the age groups, data suggested that the most exposed sub-population of [18-29] years old is from Aby village in opposite at Frambo village, the same case those who were ≥ 40 years old. It’s convenient to note that, the proportion of Mercury levels would not to be neglected among studied population especially with the resident from Aby village. So, some measures need to be taken at the political level to control mercury contamination.

Key issues on magnetic reconnection at Mercury

Magnetic reconnection processes and their impact on planetary magnetospheric dynamics exhibit significant differences due to differences in upstream solar wind conditions and internal planetary environments.Current understanding of reconnection phenomena at Mercury is rooted in the MESSENGER mission.However,direct detection of reconnection remains rare.Here,we aim to assess the limitations of MESSENGER in detecting reconnection in Mercury’s space and to discuss key issues of reconnection that will be addressed by BepiColombo,including the dynamics of magnetic flux ropes,particle acceleration,density asymmetric reconnection,IMF-driven near-tail structures,and potential modes of magnetospheric convection.

Statistical study of magnetic holes in the upstream region of Mercury’s bow shock

Magnetic holes are magnetic depression structures that exist widely in many plasma environments.The magnetic holes with durations of>1 s in the solar wind at Mercury’s orbit have drawn much attention,but the properties of the magnetic holes with shorter durations are still unclear.Here,we investigate the magnetic holes with durations of 0.1-100 s in the upstream region of Mercury’s bow shock based on observations by the MESSENGER(MErcury Surface,Space ENvironment,GEochemistry,and Ranging)spacecraft.They can be divided into two groups according to the distribution of their duration:small-duration magnetic holes(SDMHs,<0.6 s)and large-duration magnetic holes(LDMHs,>0.6 s).The duration of each group approximately obeys a log-normal distribution with a median of~0.25 s and 3 s,respectively.Approximately 1.7%(32.6%)of the SDMHs(LDMHs)reduce the magnetic field strength by more than 50%.For both groups,some structures have a linear or quasi-linear polarization,whereas others have an elliptical polarization.The magnetic hole events in both groups tend to have a higher rate of occurrence when the interplanetary magnetic field strength is weaker.Their occurrence rates are also affected by Mercury’s foreshock,which can increase(decrease)the occurrence rate of the SDMHs(LDMHs).This finding suggests that Mercury’s foreshock might be one source of the SDMHs and that the foreshock can destroy some LDMHs.These observations suggest that a new group of magnetic holes with durations of<0.6 s exist in the upstream region of Mercury’s bow shock.

Tb^(3+)-nucleic acid probe-based label-free and rapid detection of mercury pollution in food

Mercury is a threatening pollutant in food,herein,we developed a Tb^(3+)-nucleic acid probe-based label-free assay for mix-and-read,rapid detection of mercury pollution.The assay utilized the feature of light-up fluorescence of terbium ions(Tb^(3+))via binding with single-strand DNA.Mercury ion,Hg^(2+)induced thymine(T)-rich DNA strand to form a double-strand structure(T-Hg^(2+)-T),thus leading to fluorescence reduction.Based on the principle,Hg^(2+)can be quantified based on the fluorescence of Tb^(3+),the limit of detection was 0.0689μmol/L and the linear range was 0.1-6.0μmol/L.Due to the specificity of T-Hg^(2+)-T artificial base pair,the assay could distinguish Hg^(2+)from other metal ions.The recovery rate was ranged in 98.71%-101.34%for detecting mercury pollution in three food samples.The assay is low-cost,separation-free and mix-to-read,thus was a competitive tool for detection of mercury pollution to ensure food safety.

Rational Synthesis of Crystalline Covalent Triazine Framework with Methylthio Pendant Arms for Efficient Mercury(Ⅱ)Adsorption

The interest in curtailing environmental pollution issues through physical separation processes has inspired an extensive search for novel nanoporous materials with exceptional adsorption capabilities.Covalent triazine frameworks(CTFs),emerged as a class of crystalline covalent organic frameworks(COFs),have been widely examined for various separation applications,owing to their large porosity,high stability,and rich nitrogen(N)doping.The development of CTFs for efficient adsorption of mercury(Ⅱ)(Hg^(2+))is of great importance for the field,whereas it is rarely attempted,on account of limited synthetic strategies and unknown structural-property relations of conventional CTFs derived from ionothermal approaches.Herein,we report rational synthesis of a crystalline CTF with methylthio pendant arms for efficient removal of Hg^(2+)with an exceptional capacity of 751 mg·g^(-1),ranking at the top among previously-reported adsorbents.This work may open up new possibility in the synthesis of COFs for various separations.

Physiological Mechanism of Exogenous Selenium in Alleviating Mercury Stress on Pakchoi(Brassica campestris L.)

The objective of this study was to explain the physiological mechanisms through which Na_(2)SeO_(3) mitigates the growth and developmental inhibition of pakchoi under HgCl_(2)stress.The results showed that treatment with HgCl_(2)(40 mg L^(−1))led to reduced biomass,dwarfing,root shortening,and root tip necrosis in pakchoi.Compared to control(CK),the activities of superoxide dismutase(SOD)and peroxidase(POD)in Hg treatment increased,and the content of malondialdehyde(MDA)also dramatically increased,which negatively impacted the growth of pakchoi.Low concentrations of Na_(2)SeO_(3)(0.2 mg L^(−1))significantly increased the content of soluble sugars compared with control,while chlorophyll,soluble proteins,free amino acids,and vitamin C had no significant changes.The results of the mixed treatments with HgCl_(2)and Na_(2)SeO_(3) suggested that selenium may be able to reduce the toxicity of mercury in pakchoi.The biomass,plant height,root length,chlorophyll content,soluble protein,other physiological indicators,and proline showed significant increases compared with the HgCl_(2)treatment.Additionally,the MDA content and mercury accumulation in pakchoi decreased.Our results revealed the antagonistic effects of selenium and mercury in pakchoi.Thus,a theoretical basis for studying pakchoi’s mercuryexcreted and selenium-rich cultivation technology was provided.

Mercury应用于辅助无机化学的教学研究

无机化学是化学领域的一个重要分支,同时也是各大高校化学类专业的一门专业基础课程。价层电子对互斥理论是无机化学教学的重中之重,是学好后续元素知识的基础,教学中存在概念抽象,二维结构图难以动态展示分子的三维结构等缺点。本文以NO^(-)_(3)、SF_(4)、PCl^(-)_(6)为例,通过Mercury软件将这三个物质进行动态展示,将理论与实验相结合,深入的叙述了这些化合物分子结构、键长、键角等的参数信息。将微观结构宏观化,抽象的化学理论形象化,将静态的二维分子结构进行三维动态展示,解决教学过程中的难点,不断提高教学效率。

Formation and growth of nanophase iron particles on the surface of Mercury revealed by experimental study

Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless planets.However,current research on space weathering focuses mainly on the Moon and certain types of asteroids.In particular,the impacts of meteoroids and micrometeoroids,radiation from solar wind/solar flares/cosmic rays,and thermal fatigue due to temperature variations are being studied.Space weathering produces various transformation products such as melted glass,amorphous layers,iron particles,vesicles,and solar wind water.These in turn lead to soil maturation,changes in visible and near-infrared reflectance spectra(weakening of characteristic absorption peaks,decreased reflectance,increased near-infrared slope),and alterations in magnetism(related to small iron particles),collectively termed the“lunar model”of space weathering transformation.Compared to the Moon and asteroids,Mercury has unique spatial environmental characteristics,including more intense meteoroid impacts and solar thermal radiation,as well as a weaker particle radiation environment due to the global distribution of its magnetic field.Therefore,the lunar model of space weathering may not apply to Mercury.Previous studies have extensively explored the eff ects of micrometeoroid impacts.Hence,this work focuses on the eff ects of solar-wind particle radiation in global magnetic-field distribution and on the weathering transformation of surface materials on Mercury under prolonged intense solar irradiation.Through the utilization of highvalence state,heavy ion implantation,and vacuum heating simulation experiments,this paper primarily investigates the weathering transformation characteristics of the major mineral components such as anorthite,pyroxene,and olivine on Mercury’s surface and compares them to the weathering transformation model of the Moon.The experimental results indicate that ion implantation at room temperature is insufficient to generate np-Fe^(0)directly but can facilitate its formation,while prolonged exposure to solar thermal radiation on Mercury’s surface can lead directly to the formation of np-Fe^(0).Therefore,intense solar thermal radiation is a crucial component of the unique space weathering transformation process on Mercury’s surface.

A monolithic integrated medium wave Mercury Cadmium Telluride polarimetric focal plane array

A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.

Multi-Pollutant Formation and Control in Pressurized Oxy-Combustion:SO_(x),NO_(x),Particulate Matter,and Mercury

Oxy-combustion is a promising carbon-capture technology,but atmospheric-pressure oxy-combustion has a relatively low net efficiency,limiting its application in power plants.In pressurized oxycombustion(POC),the boiler,air separation unit,flue gas recirculation unit,and CO_(2)purification and compression unit are all operated at elevated pressure;this makes the process more efficient,with many advantages over atmospheric pressure,such as low NO_(x)emissions,a smaller boiler size,and more.POC is also more promising for industrial application and has attracted widespread research interest in recent years.It can produce high-pressure CO_(2)with a purity of approximately 95%,which can be used directly for enhanced oil recovery or geo-sequestration.However,the pollutant emissions must meet the standards for carbon capture,storage,and utilization.Because of the high oxygen and moisture concentrations in POC,the formation of acids via the oxidation and solution of SO_(x)and NO_(x)can be increased,causing the corrosion of pipelines and equipment.Furthermore,particulate matter(PM)and mercury emissions can harm the environment and human health.The main distinction between pressurized and atmospheric-pressure oxy-combustion is the former’s elevated pressure;thus,the effect of this pressure on the pollutants emitted from POC—including SO_(x),NO_(x),PM,and mercury—must be understood,and effective control methodologies must be incorporated to control the formation of these pollutants.This paper reviews recent advances in research on SO_(x),NO_(x),PM,and mercury formation and control in POC systems that can aid in pollutant control in such systems.

Estimation of unfrozen water content of saturated sandstones using nuclear magnetic resonance, mercury intrusion porosimetry, and ultrasonic tests

The unfrozenwater content(UWC)is a crucial parameter that affects the strength and thermal properties of rocks in relation to engineering construction and geological disasters in cold regions.In this study,three different methods were employed to test and estimate the UWC of saturated sandstones,including nuclear magnetic resonance(NMR),mercury intrusion porosimetry(MIP),and ultrasonic methods.The NMR method enabled the direct measurement of the UWC of sandstones using the free induction decay(FID).The MIP method was used to analyze the pore structures of sandstones,with the UWC subsequently calculated based on pore ice crystallization.Therefore,the MIP test constituted an indirect measurement method.Furthermore,a correlation was established between the P-wave velocity and the UWC of these sandstones based on the mixture theory,which could be employed to estimate the UWC as an empirical method.All methods demonstrated that the UWC initially exhibited a rapid decrease from 0C to5C and then generally became constant beyond20C.However,these test methods had different characteristics.The NMR method was used to directly and accurately calculate the UWC in the laboratory.However,the cost and complexity of NMR equipment have precluded its use in the field.The UWC can be effectively estimated by the MIP test,but the estimation accuracy is influenced by the ice crystallization process and the pore size distribution.The P-wave velocity has been demonstrated to be a straightforward and practical empirical parameter and was utilized to estimate the UWC based on the mixture theory.This method may be more suitable in the field.All methods confirmed the existence of a hysteresis phenomenon in the freezing-thawing process.The average hysteresis coefficient was approximately 0.538,thus validating the GibbseThomson equation.This study not only presents alternative methodologies for estimating the UWC of saturated sandstones but also contribute to our understanding of the freezing-thawing process of pore water.

Feasibility Evaluation of Using Biochar-based Permeable Reactive Barrier for the Remediation of Mercury and Arsenic Composite Polluted Water Bodies

This study employed a modified biochar material to construct a permeable reactive barrier(PRB)for the treatment of water bodies polluted with mercury and arsenic.The experimental results demonstrated that the addition of goethite-modified biochar significantly enhanced the remediation efficiency of As(III),achieving a maximum removal rate of 100%.Conversely,pure biochar exhibited high efficiency in the removal of Hg(II),with a maximum removal rate approaching 100%.Furthermore,the pH level of the water significantly influenced the adsorption efficiency of heavy metal ions,with the optimal removal performance observed at a pH of 6.0.The PRB system demonstrated excellent removal rates under low concentrations of heavy metals.However,as the concentration increased,the remediation efficiency exhibited a slight decrease.In summary,the findings of this study provide compelling evidence for the use of modified biochar in the construction of PRBs for the remediation of mercury and arsenic-polluted water bodies.Furthermore,the study reveals the mechanism by which pH and heavy metal concentration influence remediation efficiency.

Substituent Effect on Mercury-199 Chemical Shifts in Some Bisarylmercurials and Aryl(2-benzothiazolylthio) mercurials

The present paper covers the 199 Hg NMR chemical shifts of 24 substituted diphenylmercurials and phenyl(2-benzothiazolylthio)mercurials. There is a good linear relationship between the chemical shift and the Hammett constant of the substituents for both series of compounds, and electron donating substituents cause the chemical shift towards downfield.

Distribution and Controlling Factors of Dissolved Gaseous Mercury and Reactive Mercury in Seawater Near Yangtze River Estuary

Complex hydrocultural conditions in the estuary affect the migration and transformation of mercury.Using two voyages in July and October 2018,Dissolved Gaseous Mercury(DGM)and Reactive Mercury(RHg)were determined to explore the source,transformation and influence of DGM content in the adjacent waters of Yangtze River Estuary in summer and autumn.The results showed the contents of DGM and RHg in summer were higher than those in autumn,and both of them were higher than those in open sea.In summer and autumn,the Yangtze River brought a higher concentration of DGM,and different flow direction and runoff resulted in differences in the high value region of the surface.The emergence of low-oxygen zones in summer was conducive to the production of DGM.In autumn,windy weather allowed seawater disturbances to promote the release of mercury from the underlying sediments,especially in shallow sea in northwest.RHg showed a higher concentration in the offshore than in the open sea in summer,but there was no such trend in autumn,reflecting the influence of less runoff input.DGM is the main product of RHg reduction,and there was a significant positive correlation between DGM and RHg in summer(r=0.356,P<0.05),while the correlation between DGM and RHg was not significant in autumn due to the influence of light intensity,wind speed and nutrients.The exchange flux of mercury in the adjacent waters of the Yangtze River Estuary was higher than that in the open sea.There was no significant difference of the release flux of mercury in summer and autumn.This article highlighted that the input of mercury from the Yangtze River runoff promotes the release of mercury in seawater,and the hypoxic zone caused by eutrophication is conducive to the production of DGM.

Assessment of Mercury Concentrations in Water and Fish Tissue Analysis in Kaw Lake, Oklahoma, 2022

The Kaw Nation has been collecting water, sediment, and fish samples from Kaw Lake and upper Arkansas River from 2007 to present to examine the concentrations of Mercury and other heavy metals to protect the health of the tribal members. Kaw Lake is in the North-Central part of Oklahoma. Kaw Lake is a permanent water body constructed in 1976 by the Army of Corps of Engineers. The Lake is consistently fed by the Arkansas River and other tributaries as runoff coming all the way from Colorado through Kansas to Kaw Lake of Oklahoma. The Lake has a surface area of 26.64 square miles (69 km2) and shoreline of 168 miles (270 km) with a total drainage area of 56,345 square miles (145,393 km2) and an average water depth of 8 meters. The water and fish samples were collected from 7 sites of Kaw Lake, once in a month and the fish samples once in a year during summertime, early July to end of July. The fish samples focused on 5 sport, predator, and bottom dwelling species of large consumable size, greater than 200 mm length and 560 grams weight. The five fish sampled were Catfish, White bass, Largemouth and Smallmouth bass, Black and White crappie. The fish and water samples were sent to Accurate Environmental Labs for detailed analysis. Predator species were analyzed as fillet and the bottom dwellings as a whole fish using EPA Method 7471A-M. Mercury from Water and Fish Tissue Samples were analyzed by Atomic Fluorescence Spectrometry. The laboratory analysis indicated that all the Mercury concentration in the fish samples except in Blue Catfish and Spotted Bass fall below the Maximum Contaminant Level (MCL) of 0.5 mg/kg.

Synthesis of Sustainable Sulfur-Rich Copolymers as Mercury Sorbents at 130℃ Using Tung Oil as an Activator

Sulfur-rich copolymers made through inverse vulcanization exhibit a wide range of potentially valuable applications, for example as adsorbents to capture mercury pollution. Among the diverse second monomers of the copolymers, vegetable oil is a renewable resource, and recycled cooking oils have an important role in saving natural products. However, they need relatively high temperatures(160–180 ℃) to react with sulfur. To develop a low-temperature(130 ℃) reaction process for non-conjugated vegetable oil, we incorporate a small amount of tung oil, which contains conjugated trienes that can produce highly active free radicals during reactions. A variety of analytical techniques(proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and dynamic mechanical analysis) are used to characterize the chemical structures and physical properties of the copolymers. The addition of tung oil is found to significantly improve the thermal stability and mechanical properties of the copolymers. We also investigate the effect of different ratios of raw materials on the gel time, free sulfur content, glass transition temperature T_(g), and degradation temperature of the copolymers. We find that increasing the amount of tung oil in the raw material mixture decreases the gel time and free sulfur content, but increases T_(g) and the degradation temperature. The copolymers exhibit a high adsorption capacity for mercury ions up to 33 mg Hg^(2+) per gram of adsorbent. These results demonstrate the feasibility of using sulfur-rich copolymers as effective mercury removal adsorbents, with the potential for further improvement by foaming the copolymers into porous materials.

Mercury accumulation,distribution,and isotopic composition in tissues of the Collared Scops Owl(Otus lettia)

Mercury is a ubiquitous contaminant known to accumulate in wildlife,particularly bird species at higher trophic levels.Knowledge of tissue-specific Hg distributions aids our understanding of Hg bioaccumulation in organisms.In this study,one adult and three juvenile Collared Scops Owls(Otus lettia)were studied to elucidate the bioaccumulation of Hg in body tissues.Six tissues and organs(feathers,nails,heart,liver,gizzard,and muscle),as well as gastric contents,were examined for total Hg(THg)and methylmercury(MeHg)contents,Hg isotopic compositions including mass-dependent fractionation(MDF;δ202Hg)and mass-independent fractionation(MIF;Δ199Hg andΔ201Hg),and C(δ13C)and N(δ15N)isotopic compositions.Tissue-specific THg and MeHg concentrations in the adult were in the ranges of 150–1360 ng/g and17–1060 ng/g,and lower in the juveniles at 91–419 ng/g and 67–350 ng/g,respectively.Theδ^(202)Hg values in the adult were strongly negative at-1.75‰±0.17‰compared with the juveniles at-0.99‰±0.25‰.The adult exhibited lower MIF values than the juveniles,at0.23‰±0.07‰forΔ^(199)Hg and 0.2‰±0.11‰forΔ^(201)Hg,comparedwith0.81‰±0.09‰and0.66‰±0.07‰,respectively.The lower adult MDF and MIF values suggest that the adult tended to accumulate negative Hg isotopes but the juvenile's positive Hg isotopes.Differences between adult and juvenile tissue Hg concentrations indicate that metabolic processes play an important role in Hg accumulation.

On the Attribution of Mercury’s Perihelion Precession

Although Newtonian gravity and general relativity predicted the precession of Mercury perihelion historically, many improved methods continue to predict the precession of Mercury during recent decades of years. Uncertainties in various predictions and observations suggest that the attribution of Mercury’s precession is still not well understood. This paper argues that the cause of Mercury’s precession is not gravity, but the inertia of material motion left over from the formation of the solar system. According to this inertia theory, the planetary precession is associated with the ratio of total mass-energy density of the system to the mass-energy of the Sun and its change over time. If other factors are not changed with time, the perihelion precession of planets per orbit is proportional to his distance relative to the Sun. The conclusions of this paper can provide more effective factor considerations for the complete description of various astronomical events and phenomena using general relativity equations.

Increasing Anthropogenic Mercury Pollution over the Last 200 Years Revealed by Lagoonal Sediments from Hainan Island,South China

The toxic heavy metal mercury(Hg)has significantly enhanced the global Hg cycle influenced by human activities over the last century.In this study,we presented a high-resolution Hg deposition history between∼1780 and 2015 AD in a sediment core from Xincun Lagoon,located in the southeastern Hainan Island,South China,and analyzed it in conjunction with geochemical elements,grain-size distribution,organic matter,and HYSPLIT backward trajectory simulation.The objective was to investigate the influencing factors affecting historical Hg deposition in relatively remote regions and assess the extent of the effects of natural background and human activities.The results showed that the Hg in the sediment was deposited primarily through atmospheric deposition,which was closely related to regional and even global human activities.Anthropogenic Hg contamination increased gradually from the 1830s to 1850s,possibly due to Hg emissions from Opium Wars I and II occurring in southeastern China.High broad peaks of anthropogenic Hg were observed during the 1910s to 1950s and in the 1980s,likely associated with the two world wars and modern Chinese wars.In addition,a further sharp increase in anthropogenic Hg from the mid-1970s to the present occurred,likely originating from the intense industrial activities in China triggered by the reform and opening-up policy of China in 1978 and some countries in Southeast Asia.