Environmental, hydrological, and social impacts of coal and nonmetal minerals mining operations.

Mining and mineral exploration has many effects on the surrounding environment. The present study reviews the hydrological and environmental impacts of coal and nonmetal mining operations by mine lifecycle stages and facility patterns. Further, a critical review of regulations and policies in South Korea focusing on the mining-water interaction, conservation, and management was performed to emphasize the current state of legislation in the country. The counties where mining was the primary employer in Gangwon-do province in South Korea were assessed for the mining impact on the community's social life and com-pared to the non-mining counties in the same province. The results of the comparative study showed the less education, healthcare and employment chances in mining counties than the adjacent counties with no mining activities.

Microbial mediated reaction of dimethylarsinic acid in wetland water and sediments.

The biogeochemical reactions of dimethylarsinic acid (DMAs(V)) were investigated using simulated wetland systems in a laboratory. DMAs(V) was injected into the wetland water, and the As concentrations in the water, plants, and sediments were monitored. Aqueous and solid-phase As speciation was evaluated, and the results revealed that the DMAs(V) was completely transported to the sediments and plants. X-ray absorption spectroscopic measurement of the As in the sediment revealed that approximately 85-95% of As existed as inorganic As species, demonstrating the important role of microorganisms in the biogeochemical reaction of DMAs(V). The influences of microbes were further investigated in smaller batches under aerobic and anaerobic conditions. The microbial batch results showed that DMAs(V) demethylation reduced the total aqueous As concentration, demonstrating that As(V) has higher affinity to wetland sediment than DMAs(V). The redox conditions were also revealed as an important controlling factor of the As reaction and, under anaerobic conditions, we observed the presence of the most toxic form of inorganic As(III) in the aqueous phase. Although this study reports one example from a specific wetland, the important roles of the redox conditions and microbial influences were identified from the comprehensive analysis of As speciation and mass balance.

Arsenic removal characteristics of natural Mn-Fe binary coating on waste filter sand from a water treatment facility.

In this study, the arsenic (As) removal characteristics of a Mn-Fe binary coating formed on waste sand filter of an acid mine drainage treatment facility are investigated. Owing to the Mn-Fe binary coating forming on the surfaces of the sand grains, its potential for arsenic removal, particularly As(III), was evaluated and characterized through batch experiments and x-ray absorption spectroscopy. Sorption isotherms reveal that the Mn-Fe binary coating exhibits comparable removal efficiencies for As(III) and As(V) under low initial As concentrations. However, at higher initial As(III) and As(V) concentrations, the As(III) removal efficiency increases because of newly formed active adsorption sites from reductive dissolution of Mn. The oxidation of the As(III) and reduction of the Mn oxide phases are verified through As K-edge and Mn K-edge X-ray absorption near edge fine structure analysis. The outstanding As(III) removal efficiency of the Mn-Fe binary coating suggests synergy of Fe- and Mn-oxides, highlighting a potential application for this coating system. The natural formation of binary coating through acid mine drainage treatment reported in this study indicates that similar coating can form naturally in other environments, thus, providing plausible natural attenuation processes for arsenic immobilization.

Precise control of heat-treatment conditions to improve the catalytic performance of V2O5/TiO2 for H2S removal.

The purpose of this study is to investigate the influences of atmospheric gas and temperature while preparing V2O5/TiO2 catalysts to find a suitable heat-treatment method to improve catalytic performance during the process of H2S removal. The catalysts prepared by wet-impregnation were heat-treated at different temperatures (400 or 600 â„ƒ) under various atmospheres (Air, N2, or H2). The catalytic tests demonstrated that the catalyst heat-treated at 400 â„ƒ under N2 atmosphere (N-400) possessed excellent catalytic activities regarding H2S conversion (96.4%) and sulfur yield (89.1%). The characterization results revealed that the mild reducing condition employed for N-400 led to the formation of partially reduced V2O5 crystals and a strong V-Ti interaction owing to the anatase TiO2 phase, resulting in the high oxygen vacancies on the catalyst surface. However, severe reducing conditions (H2 or N2 with 600 â„ƒ) or the higher temperature (600 â„ƒ) induced highly reduced V2O5-x or rutile TiO2 related to a weak V-Ti interaction, respectively, which facilitated lower oxygen vacancies. This study is the first to demonstrate the significance of a precisely controlled heat-treatment to enhance catalytic performance for H2S removal.

Effects of TNFα on Dynamic Cytosolic Ca2 + and Force Responses to Muscarinic Stimulation in Airway Smooth Muscle.

Previously, we reported that in airway smooth muscle (ASM), the cytosolic Ca2+ ([Ca2+] cyt ) and force response induced by acetyl choline (ACh) are increased by exposure to the pro-inflammatory cytokine tumor necrosis factor α (TNFα). The increase in ASM force induced by TNFα was not associated with an increase in regulatory myosin light chain (rMLC20) phosphorylation but was associated with an increase in contractile protein (actin and myosin) concentration and an enhancement of Ca2+ dependent actin polymerization. The sensitivity of ASM force generation to elevated [Ca2+] cyt (Ca2+ sensitivity) is dynamic involving both the shorter-term canonical calmodulin-myosin light chain kinase (MLCK) signaling cascade that regulates rMLC20 phosphorylation and cross-bridge recruitment as well as the longer-term regulation of actin polymerization that regulates contractile unit recruitment and actin tethering to the cortical cytoskeleton. In this study, we simultaneously measured [Ca2+] cyt and force responses to ACh and explored the impact of 24-h TNFα on the dynamic relationship between [Ca2+] cyt and force responses. The temporal delay between the onset of [Ca2+] cyt and force responses was not affected by TNFα. Similarly, the rates of rise of [Ca2+] cyt and force responses were not affected by TNFα. The absence of an impact of TNFα on the short delay relationships between [Ca2+] cyt and force was consistent with the absence of an effect of [Ca2+] cyt and force on rMLC20 phosphorylation. However, the integral of the phase-loop plot of [Ca2+] cyt and force increased with TNFα, consistent with an impact on actin polymerization and, contractile unit recruitment and actin tethering to the cortical cytoskeleton.

Wafer-Scale Unidirectional Alignment of Supramolecular Columns on Faceted Surfaces.

The long-range alignment of supramolecular structures must be engineered as a first step toward advanced nanopatterning processes aimed at miniaturizing features to dimensions below 5 nm. This study introduces a facile method of directing the orientation of supramolecular columns over wafer-scale areas using faceted surfaces. Supramolecular columns with features on the sub-5 nm scale were highly aligned in a direction orthogonal to that of the facet patterning on unidirectional and nanoscopic faceted surface patterns. This unidirectional alignment of supramolecular columns is also observed by varying the thickness of the supramolecular film or by altering the dimensions of the facet pattern. The ordering behavior of the supramolecular columns can be attributed to the triangular depth profile of the bottom facet pattern. Furthermore, this directed self-assembly principle allows for the continuous alignment of supramolecular structures across ultralarge distances on flexible patterned substrates.

Dynamic cytosolic Ca2+ and force responses to muscarinic stimulation in airway smooth muscle.

During agonist stimulation of airway smooth muscle (ASM), agonists such as ACh induce a transient increase in cytosolic Ca2+ concentration ([Ca2+]cyt), which leads to a contractile response [excitation-contraction (E-C) coupling]. Previously, the sensitivity of the contractile response of ASM to elevated [Ca2+]cyt (Ca2+ sensitivity) was assessed as the ratio of maximum force to maximum [Ca2+]cyt. However, this static assessment of Ca2+ sensitivity overlooks the dynamic nature of E-C coupling in ASM. In this study, we simultaneously measured [Ca2+]cyt and isometric force responses to three concentrations of ACh (1, 2.6, and 10 µM). Both maximum [Ca2+]cyt and maximum force responses were ACh concentration dependent, but force increased disproportionately, thereby increasing static Ca2+ sensitivity. The dynamic properties of E-C coupling were assessed in several ways. The temporal delay between the onset of ACh-induced [Ca2+]cyt and onset force responses was not affected by ACh concentration. The rates of rise of the ACh-induced [Ca2+]cyt and force responses increased with increasing ACh concentration. The integral of the phase-loop plot of [Ca2+]cyt and force from onset to steady state also increased with increasing ACh concentration, whereas the rate of relaxation remained unchanged. Although these results suggest an ACh concentration-dependent increase in the rate of cross-bridge recruitment and in the rate of rise of [Ca2+]cyt, the extent of regulatory myosin light-chain (rMLC20) phosphorylation was not dependent on ACh concentration. We conclude that the dynamic properties of [Ca2+]cyt and force responses in ASM are dependent on ACh concentration but reflect more than changes in the extent of rMLC20 phosphorylation.

Field demonstration of solar-powered electrocoagulation water treatment system for purifying groundwater contaminated by both total coliforms and arsenic.

People who drink groundwater in rural areas of Southeast Asia are exposed to pathogens and arsenic (As)-related health problems. A water treatment system consisting of electrocoagulation reactors, using iron (Fe) electrodes and a filtration tank, was designed to treat complex contaminated groundwater for drinking. Its applicability was demonstrated near the Red River in Vietnam. The water treatment system reduced 10.3 CFU/mL of total coliform and 376 µg/L of As(III) in the groundwater to 0 CFU/mL and 6.68 µg/L, respectively. Total coliforms were attenuated by Fe(II) infiltration or enmeshed during Fe precipitate formation. Of the total As, 43% formed As(III) complexation with the Fe precipitates and the other 57% was oxidized to As(V) then adsorbed to Fe precipitates. The Fe precipitates, containing total coliforms and As, were separated from the discharge water in the filtration tank. The system required 49 W of power to operate, which equates to 423 kWh/year, to continuously purify 0.5 t water/day. This requirement was powered by a 380-750 W solar panel, without external energy supply, making the water treatment system an appropriate option for addressing drinking water problems in rural areas.

Aging effects on fractionation and speciation of redox-sensitive metals in artificially contaminated soil.

Artificially contaminated soil is often used in laboratory experiments as a substitute for actual field contaminated soils. In the preparation and use of laboratory contaminated soils, questions remain as to how much and how long metals remain in labile form and in their oxidation state during the contamination process. Therefore, the objectives of this study were to determine if the speciation of added contaminants can be retained in the original form and to observe the change in lability of each element with aging time. In this study, natural soil was artificially polluted with five redox-sensitive toxic elements in their oxidized or reduced forms, i.e., As(III)/As(V), Sb(III)/Sb(V), Cr(III)/Cr(VI), Mo(VI), and W(V). Metal distribution was measured in progressive chemical fractionation using sequential extraction methods in contaminated soils after 3, 100, and 300 days of aging. The results indicated that the more strongly bound fraction of metals increased by day 100; whereas the fractions were not significantly different from those in the 300-day-aged soil. Among five metals, the ratio of weakly-bound fractions remained highest in As- and lowest in Cr-contaminated soils. The W(VI)-contaminated soil showed strong sorption without changes in speciation during aging. The oxidized or reduced metal species converged to occur as a single species under given soil conditions, regardless of the initial form of metal used to spike the soil. Both As and Sb existed as their oxidized form while Cr existed as its reduced form. The results of this study may provide a useful and practical guideline for artificial soil contamination.

Thermal effect on the leachability of extraframework Co2+ in zeolite X.

A partially Co2+-exchanged zeolite X was thermally treated to simulate the effect of decay heat on the leachability of extraframework Co2+. To have a mechanistic insight into thermal effect, X-ray diffraction, scanning electron microscopy, 27Al magic angle spinning nuclear magnetic resonance spectroscopy, and Co K-edge X-ray absorption spectroscopy were employed with leaching tests. Although thermal treatment at ≤ 600 °C did not lead to the collapse of zeolite framework, it removed H2O molecules from the coordination shell of extraframework Co2+, which in turn changed its coordination structure in a way to strengthen the interaction between Co2+ and the lattice oxygens. In leaching tests, the sample treated at higher temperature for a longer period showed less remobilized Co2+ by forming a Co(OH)2-like surface precipitate and a Co hydrotalcite-like phase. Notably, the formation of the latter phase indicated the abstraction of the framework Al, the extent of which increased with the treatment temperature and duration. Two mechanisms, the concurrent extraction of Al with Co2+ remobilization and the hydrolysis-promoted Al abstraction, were proposed to account for thermally promoted dealumination. This study suggests that the exposure of Co2+-exchanged zeolite X to decay heat lessen the risk of extraframework Co2+ to be reintroduced into groundwater.

Genomic and Physiological Properties of a Facultative Methane-Oxidizing Bacterial Strain of Methylocystis sp. from a Wetland.

Methane-oxidizing bacteria are crucial players in controlling methane emissions. This study aimed to isolate and characterize a novel wetland methanotroph to reveal its role in the wetland environment based on genomic information. Based on phylogenomic analysis, the isolated strain, designated as B8, is a novel species in the genus Methylocystis. Strain B8 grew in a temperature range of 15 °C to 37 °C (optimum 30-35 °C) and a pH range of 6.5 to 10 (optimum 8.5-9). Methane, methanol, and acetate were used as carbon sources. Hydrogen was produced under oxygen-limited conditions. The assembled genome comprised of 3.39 Mbp and 59.9 mol% G + C content. The genome contained two types of particulate methane monooxygenases (pMMO) for low-affinity methane oxidation (pMMO1) and high-affinity methane oxidation (pMMO2). It was revealed that strain B8 might survive atmospheric methane concentration. Furthermore, the genome had various genes for hydrogenase, nitrogen fixation, polyhydroxybutyrate synthesis, and heavy metal resistance. This metabolic versatility of strain B8 might enable its survival in wetland environments.

Cytoskeletal remodeling slows cross-bridge cycling and ATP hydrolysis rates in airway smooth muscle.

During isometric activation of airway smooth muscle (ASM), cross-bridge cycling and ATP hydrolysis rates decline across time even though isometric force is sustained. Thus, tension cost (i.e., ATP hydrolysis rate per unit of force during activation) decreases with time. The "latch-state" hypothesis attributes the dynamic change in cross-bridge cycling and ATP hydrolysis rates to changes in phosphorylation of the regulatory myosin light chain (rMLC20 ). However, we previously showed that in ASM, the extent of rMLC20 phosphorylation remains unchanged during sustained isometric force. As an alternative, we hypothesized that cytoskeletal remodeling within ASM cells results in increased internal loading of contractile proteins that slows cross-bridge cycling and ATP hydrolysis rates. To test this hypothesis, we simultaneously measured isometric force and ATP hydrolysis rate in permeabilized porcine ASM strips activated by Ca2+ (pCa 4.0). The extent of rMLC20 phosphorylation remained unchanged during isometric activation, even though ATP hydrolysis rate (tension cost) declined with time. The effect of cytoskeletal remodeling was assessed by inhibiting actin polymerization using Cytochalasin D (Cyto-D). In Cyto-D treated ASM, isometric force was reduced while ATP hydrolysis rate increased compared to untreated ASM strips. These results indicate that external transmission of force, cross-bridge cycling and ATP hydrolysis rates are affected by internal loading of contractile proteins.

Effect of redox variation on the geochemical behavior of Sb in a vegetated Sb(V)-contaminated soil column.

This study examined the geochemical behavior of antimony (Sb) in a vegetated contaminated soil column consisting of unsaturated rhizosphere and a waterlogging layer. The results showed a reducing condition (Oxidation-Reduction Potential (ORP) of -171 mV) was formed in about 5 days in the waterlogging zone. The amount of Sb released was higher under the oxidizing unsaturated-rhizosphere compared to that in the waterlogging zone possibly because of the weaker affinity of Sb(V) to Mn- and/or Fe-oxides in soil. The fraction of Sb(III) in the dissolved total Sb increased with time when soil redox states were subjected to a further reduction. Solid phase Sb K-edge X-ray absorption spectroscopy (XAS) of soils showed that Sb(III) fraction of the deeper layer soil increased while the unsaturated upper soil solely composed Sb(V). In this study, 250 mg/kg of Sb pollution did not significantly affect plant growth and no significant transport of Sb occurred from the soil to plant. However, changes in redox conditions within the soil column induced a shift in soil microbial communities. Consequently, the importance of redox states of soil on geochemical behavior of Sb and the effects of soil flooding or waterlogging deserve attention in the management of Sb-contaminated soil.

Effect of FeS on mercury behavior in mercury-contaminated stream sediment: A case study of Pohang Gumu Creek in South Korea.

This study investigated mercury contamination with respect to the sediment characteristics in Gumu Creek near the Pohang Industrial Complex, South Korea. The contaminated sediment had high levels of Hg, exceeding 250 mg Hg/kg sediment at the sampling position, and high concentrations of iron, sulfur, and organic carbon under extreme anaerobic conditions. The anoxic condition of the sediment produced large amounts of FeS. Hg L3-edge EXAFS analysis revealed that FeS controlled the Hg species in the sediment mainly as ß-HgS like precipitation or Hg-S complexation. We also speculated that the presence of FeS induced the abiotic reduction of Hg(II) to Hg(0) and consequently suppressed the formation of highly toxic methylated mercury species. The results obtained in this study are mostly consistent with those reported in previous studies of geochemical reactions of FeS in controlling Hg(II) under pure FeS mineral systems under laboratory scenarios. This study demonstrates that the laboratory controlled reaction scenarios can explain the field behavior of Hg in the contaminated anoxic sediment of the Gumu Creek site.

Water defluorination using granular composite synthesized via hydrothermal treatment of polyaluminum chloride (PAC) sludge.

In this work, we newly synthesized granular composite (GASA) via hydrothermal treatment of polyaluminum chloride (PAC) and subsequently granulation pelleting with starch gel as an organic binder. The resulting composite was characterized with analytic instruments, and the feasibility of utilizing GASA as adsorbent for the removal of fluoride (F-) was tested in the batch and column experiments. The characterization results revealed that GASA possessed a spherical/porous framework consisting of aluminosilicate (i.e., ordered albite, NaAlSiO3O8). The results of final pH effect experiments and XRD/XPS analyses showed the dominant adsorption mechanisms of F- on GASA were electrostatic attraction by protonated surface Al-OH, ligand exchange between surface hydroxyl groups and F ions, and surface precipitation (i.e., cryolite formation). Based on the results of adsorption kinetics and adsorption isotherm, granulation resulted in the relatively slow kinetics of F adsorption compared to the powder type, but was preferred to retain good adsorption capacity. The regeneration possibility of GASA was also proven with the adsorption/desorption cyclic test. In the column study, 15-cm length of the GASA layer and the flow rate less than 0.85 mL min-1 were proposed to keep the satisfactory level of F in water. The experimental results offer a potential of PAC sludge-derived composite as adsorbent for the removal of F from water.

A multidisciplinary assessment of the impact of spilled acids on geoecosystems: an overview.

We developed and applied a multidisciplinary approach to the impact of an accidentally spilled acid on the underlying geomedia and subsurface environment, based on the concept of geoecosystem. We used mineralogical, geochemical, microbiological, and ecotoxicological techniques to identify and assess the multiple aspects involved. First, we constructed a conceptual model for the acid interactions with the underlying subsurface environment by introducing the concept of a geoecosystem-a multicomponent system composed of inorganic, organic, and biological components to describe the subsurface environment. Second, we designed and manufactured a two dimensional cell to visualize acid transport through geomedia. Third, we hypothesized that the acids are neutralized through dissolution of minerals and protonation of functional groups on the surfaces of minerals and organic matter. We tested this hypothesis by conducting batch-type geomedia-acid reaction and surface titration experiments. Fourth, we observed changes in soil microbial communities before and after the acid exposure and neutralization treatment. Fifth, we performed flow-through experiments using columns packed with soil samples pre-contaminated with arsenic to investigate potential longer term, secondary effects of remnant acids on geoecosystems. Finally, we conducted ecotoxicological investigations using various geomedia and observed that suitability of the geoecosystem as a habitat deteriorated to different degrees depending on the respective systems' acid neutralizing power. We conclude that a holistic understanding of the interactions among the multiple components of geoecosystems and subsequent estimation of the influenced area requires a multidisciplinary approach such as those used in this study. Based on the findings of this study, we propose geoecosystems' vulnerability defined as the reciprocal of their acid-neutralizing capacity against the moving acid fronts and present this concept as central to a quantitative assessment of the impact of acid spills on geoecosystems. We also inventoried the essential components, factors, and parameters necessary in developing geoecosystems' acid vulnerability assessment system.

Cardiac troponin-I phosphorylation underlies myocardial contractile dysfunction induced by hypothermia rewarming.

Rewarming the intact heart after a period of hypothermia is associated with reduced myocardial contractility, decreased Ca2+ sensitivity, and increased cardiac troponin-I (cTnI) phosphorylation. We hypothesized that hypothermia/rewarming (H/R) induces left ventricular (LV) contractile dysfunction due to phosphorylation of cTnI at Ser23/24. To test this hypothesis, the response of wild-type mice (n = 7) to H/R was compared with transgenic (TG) mice expressing slow skeletal TnI (TG-ssTnI; n = 7) that lacks the Ser23/24 phosphorylation sites. Hypothermia was induced by surface cooling and maintained at 23-25°C for 3 h. Subsequently, the animals were rewarmed to 37°C. LV systolic and diastolic function was assessed using a 1.4 F pressure-volume Millar catheter introduced via the right carotid artery. At baseline conditions, there were no significant differences in LV systolic function between wild-type and TG-ssTnI mice, whereas measurements of diastolic function [isovolumic relaxation constant (τ) and end-diastolic pressure-volume relationship (EDPVR)] were significantly (P < 0.05) reduced in TG-ssTnI animals. Immediately after rewarming, significant differences between groups were found in cardiac output (CO; wild-type 6.6 ± 0.7 vs. TG-ssTnI 8.8 ± 0.7 mL/min), stroke work (SW; wild-type 796 ± 112 vs. TG-ssTnI 1208 ± 67 mmHg/µL), and the preload recruited stroke work (PRSW; wild-type 38.3 ± 4.9 vs. TG-ssTnI 68.8 ± 8.2 mmHg). However, EDPVR and τ returned to control levels within 1 h in both groups. We conclude that H/R-induced LV systolic dysfunction results from phosphorylation of cTnI at Ser23/24.NEW & NOTEWORTHY Rewarming following a period of accidental hypothermia leads to a form of acute cardiac failure (rewarming shock), which is in part due to reduced sensitivity to Ca2+ activation of myocardial contraction. The results of the present study support the hypothesis that rewarming shock is due to phosphorylation of cardiac troponin I.

Redox transformation of soil minerals and arsenic in arsenic-contaminated soil under cycling redox conditions.

Changes in the saturation degree of aquifers control the geochemical reactions of redox-sensitive elements such as iron (Fe), sulfur (S), and arsenic (As). In this study, the effects of redox conditions and the presence of Fe and S on the behavior of As in a soil environment were investigated by observation in a batch experimental system. Arsenic was stable on Fe(III) solid surface in an oxidizing environment but was easily released into the aqueous phase following the reductive dissolution of Fe during an anoxic period. The alternating redox cycles led to a change in the concentrations of Fe, S, and As in both the aqueous and solid phases. The composition of Fe minerals changed to a less crystalline phase while that of solid phase As changed to a more reduced phase in both the As-contaminated natural soil and FeS-amended soil batch systems. This tendency was more prominent in the batch containing higher amounts of total Fe and S. These results show that a redox cycle can increase the possibility of As contamination of groundwater during dissolution and reprecipitation of Fe minerals and simultaneous microbial reduction of S and/or As species.

Self-Assembled Nanostructure of C60-Amphiphilic Molecules Complex in Aqueous Solution: A Small Angle Neutron Scattering Study.

In this research, self-assembled nanostructures of C60-agents dispersed in water were investigated using the small angle neutron scattering (SANS) technique. SANS measurements of the C60-agent (surfactant and block copolymers) dispersions showed that clumps of several C60 molecules remain aggregated after ultrasonication and that the C60 aggregates are encapsulated by the agent (surfactants or polymers), existing as a stable dispersion in water. While the shell thickness of dispersed C60-agents (2.04 nm-3.41 nm) differs according to the surfactants and polymers, the formation of C60 aggregates with 4 or 5 fullerenes, where the radius of the C60 aggregates ca. 0.67 nm was not affected. The UV-vis spectrum of the dispersions further supports the formation of C60 aggregates.

Unexpected Phase Behavior of Pluronic Polymer-Organic Derivative Mixtures Depending on Temperature in Aqueous Solution.

The phase behavior of amphiphilic Pluronic block copolymers in aqueous solution is of importance for a broad spectrum of practical applications but has not been fully exploited yet. Here, the phase behavior of the mixture of the Pluronic P65 and P105 triblock copolymer, (which have the same composition of PEO and PPO but the different molecular weight) and organic derivative, 5-methyl salicylic acid (5mS), in aqueous solution has been investigated by using small angle neutron scattering (SANS). According to the temperature and the 5mS concentration, SANS measurements showed that the P65-5mS mixtures sequentially transform into a random coil, sphere, vesicle, cylinder, and vesicle again, while the P105-5mS mixtures form spherical particles with two different sizes without any topological phase transition. Upon heating, the formation of two different kinds of the vesicle structure of amphiphilic block copolymer in aqueous solution is very unusual. This phase behavior was explained as the coupled effect of the simultaneous increase of the hydrophobicity of the polymer and the solubility of 5mS molecules upon heating. This result gives fundamental information for the practical use of Pluronic polymers in nano- and bio-science and it provides a simple route for the fabrication of the nanostructure without a complicated procedure.