Eruption dynamics of CO₂-driven cold-water geysers: Crystal, Tenmile geysers in Utah and Chimayo geyser in New Mexico

Watson, Z.T.,Han, W.S.,Keating, E.H.,Jung, N.H.,Lu, M. North-Holland Pub. Co ; Elsevier Science Ltd 2014 Earth and planetary science letters Vol.408 No.-

The CO<SUB>2</SUB> bubble volume fraction, eruption velocity, flash depth and mass emission of CO<SUB>2</SUB> were determined from multiple wellbore CO<SUB>2</SUB>-driven cold-water geysers (Crystal and Tenmile geysers, in Utah and Chimayo geyser in New Mexico). At shallow depths the bubble volume fraction ranges from 0 to 0.8, eruption velocities range from 2 to 20 m/s and flash depths are predominately shallow ranging from 5 to 40 m below the surface. Annual emission of CO<SUB>2</SUB> is estimated to be (4.77+/-1.92)x10<SUP>3</SUP>, (6.17+/-1.73)x10<SUP>1</SUP>, (6.54+/-0.57)x10<SUP>1</SUP>t/yr for Crystal, Tenmile and Chimayo geysers, respectively. These estimates are coherent with Burnside et al. (2013) showing that the rate of CO<SUB>2</SUB> leakage from wellbores is greater than fault-parallel or diffuse CO<SUB>2</SUB> leakage. The geyser plumbing geometry consists of a vertical wellbore which allows for the upward migration of CO<SUB>2</SUB>-rich fluids due to artesian conditions. The positive feedback system of a CO<SUB>2</SUB>-driven eruption occurs within the well. Active inflow of CO<SUB>2</SUB> into the regional aquifers through faulted bedrock allows geysering to persist for decades. Crystal geyser erupts for over 24 h at a time, highlighting the potential for a wellbore in a natural environment to reach relatively steady-state high velocity discharge. Mitigating high velocity CO<SUB>2</SUB>-driven discharge from wellbores will, however, be easier than mitigating diffuse leakage from faults or into groundwater systems.

Are the ratios of the two concentrations at steady state in the medium pairs of air-water, air-soil, water-soil, water-sediment, and soil-sediment?

Kim, H.S.,Kim, S.K.,Kim, J.G.,Lee, D.S. Elsevier Pub.Co 2016 Science of the Total Environment Vol.553 No.-

For optimization and evaluation of a steady state multimedia model, concurrent multimedia monitoring data of steady state are necessary. In the lack of emission rate information, the primary aim of the present work was to assess if five concentration ratios (CRs) (C<SUB>water</SUB>/C<SUB>air</SUB>, C<SUB>soil</SUB>/C<SUB>air</SUB>, C<SUB>sediment</SUB>/C<SUB>soil</SUB>, C<SUB>water</SUB>/C<SUB>soil</SUB>, and C<SUB>sediment</SUB>/C<SUB>water</SUB>) of chemical compounds are at steady state in South Korea. A total of 16,676 CRs values were calculated using 74,641 concurrent multimedia (air, water, soil and sediment) monitoring data from 96 areas for 45 semi-volatile organic compounds (polychlorinated dibenzo-p-dioxins/furans, polybrominated diphenyl ethers, phthalates, and polycyclic aromatic hydrocarbons). Test of steady state indicated that CR is statistically at steady state with an overall occurrence rate of 70% of the 223 tested cases while the rates of individual chemical groups were 94.5%, 88%, 82.5%, and 37.6% for polycyclic aromatic hydrocarbons, phthalates, polybrominated diphenyl ethers, and polychlorinated dibenzo-p-dioxins/furans, respectively. About 83% of the steady state CRs resulted from scattering of two concentrations in each of the medium pairs without a certain temporal trend while the rest due to closely co-varying two concentrations. Analysis of the 95% confidence interval of the fugacity ratio indicated that CRs at steady state may occur in equilibrium state with higher chances than CRs at unsteady state. A total of 156 point values representing the CRs at steady state were determined that can be used for optimization and evaluation of steady state one-box multimedia models. However, potential influences of the uncertainties of the values arisen from the scattering of the concentration data should quantitatively be assessed in the model optimization and evaluation.

Electronically tuned sulfonamide-based probes with ultra-sensitivity for Ga³⁺ or Al³⁺ detection in aqueous solution

Kumar, A.,Chae, P.S. Elsevier Pub. Co 2017 Analytica chimica acta Vol.958 No.-

<P>Three electronically tuned fluorescent probes (1-3) were synthesized by conjugating a fluorescent unit to N,N-bis-(hydroxyethyl)ethylenediamine. Probe 1 bearing an electron-deficient naphthalenedimide unit did not give a fluorescence response to the presence of various metal ions including monovalent metal ions (Na+, K+, and Ag+), divalent metal ions (Ca2+, Cd2+, Co2+, Ni2+, Cu2+, Hg2+, Pb2+, and Zn2+) and trivalent metal ions (Al3+, Ga3+, Fe3+, and Cr3+) in an aqueous solution. By contrast, probes 2 and 3 possessing 1,8-naphthalimide and pyrene fluorophores, respectively, exhibited selective fluorescent 'OFF-ON' behaviors as a result of Ga3+/Al3+ binding among the diverse metal ions, suggesting the importance of fluorophore electronic character with regard to metal ion sensing. The ethylenediamine analog of probe 3, corresponding to probe 4, was unable to yield a significant change in fluorescence intensity in the presence of any metal ions tested here, revealing the essential role of two hydroxyl groups for metal ion binding. A high association constant of Ka = 2.99 x 10(5) M-1 was obtained for probe 3 with Ga3+, with a limit of detection (LOD) of 10 nM. This LOD is the lowest value known for Ga3+ detection using chemical sensors. Along with an increase in aggregate sizes, PET suppression of probes upon metal ion binding was the primary contributor to the enhancement in fluorescence emission necessary for the sensitive detection of the target ions. The probe-metal ion complexes were fully characterized via TEM, FE-SEM, H-1 NMR, fluorescence spectroscopy techniques and DFT calculations. (C) 2016 Elsevier B.V. All rights reserved.</P>

Clinical characteristics of parkinsonism in frontotemporal dementia according to subtypes

Park, Hee Kyung,Park, Kee Hyung,Yoon, Bora,Lee, Jae-Hong,Choi, Seong Hye,Joung, Jee H.,Yoon, Soo Jin,Kim, Byeong C.,Kim, Seung Hyun,Kim, Eun-Joo,Na, Duk L.,Park, Kyung Won Elsevier Pub. Co 2017 Journal of the neurological sciences Vol.372 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>We investigated the prevalence of parkinsonism in frontotemporal dementia (FTD) subtypes and the cognitive and behavioral differences between FTD with and without parkinsonism in a well-structured, prospective cohort.</P> <P><B>Methods</B></P> <P>One hundred and ninety-one FTD patients were enrolled and all patients underwent comprehensive neurological evaluations, neuropsychological tests, and the Unified Parkinson's Disease Rating Scale.</P> <P><B>Results</B></P> <P>The prevalence of parkinsonism was 38.7% (74 patients), and included 33 (46.5%) behavioral variant FTD (bvFTD), 16 (24.2%) semantic dementia (SD), 19 (45.2%) progressive nonfluent aphasia (PNFA), and 6 (50%) FTD associated with motor neuron disease (FTD-MND). SD patients with parkinsonism had higher CDR sum of boxes scores (9.7±4.5 vs 6.2±4.5, <I>p</I> =0.024), frontal behavioral inventory total score (33.7±20.5 vs 24.3±14.5, <I>p</I> =0.045), and executive function score of frontal executive dysfunction, disinhibition, and apathy (28.9±13.7 vs 19.2±12.9, <I>p</I> =0.021) than those without parkinsonism. Seoul Instrumental Activities of Daily Living score (bvFTD: 23.5±11.7 vs 17.3±11.3, <I>p</I> =0.031, SD: 23.1±11.1 vs 11.3±9.3, <I>p</I> =0.005) was higher for bvFTD and SD with parkinsonism than for those without parkinsonism.</P> <P><B>Conclusions</B></P> <P>Parkinsonism is found to be more common in patients with bvFTD, PNFA, and FTD-MND patients than those with SD. Behavioral disturbances were more prominent in SD with parkinsonism than without. Additional studies are needed to determine the pathomechanism and optimal treatment of parkinsonism in different FTD subtypes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Parkinsonism was present in about 40% of FTD and in all FTD subtypes. </LI> <LI> Global cognitive deficits did not differ between FTD with and without parkinsonism. </LI> <LI> Behavioral disturbances were more severe in SD patients with parkinsonism than in those without. </LI> <LI> Instrumental ADL index was more impaired in bvFTD and SD patients with parkinsonism than in those without. </LI> <LI> Parkinsonism may serve as an important clue to the diagnosis of FTD. </LI> </UL> </P>

Effect of sulfidation and dissolved organic matters on toxicity of silver nanoparticles in sediment dwelling organism, Chironomus riparius

Lee, S.W.,Park, S.Y.,Kim, Y.,Im, H.,Choi, J. Elsevier Pub.Co 2016 Science of the Total Environment Vol.553 No.-

The properties, fate, and toxicity of silver nanoparticles (AgNPs) are readily modified in the environment. Thus, in order to predict the environmental impact of AgNPs, the toxicity test should be conducted to assess the interactions of AgNPs with environmental matrices. Dissolved organic matter (DOM) is known to mitigate AgNPs toxicity in natural systems, and it is also known that silver binds strongly to sulfur. Little is known, however, about the effect of sulfidation and to what extent it could compete with DOM in the sediment. We therefore investigated the effect of sulfide on a sediment dwelling organism, Chironomus riparius using ecotoxicity endpoints. We then investigated how sulfide and a combination of sulfide and DOM affect the toxicity of AgNPs in C. riparius. We also monitored the concentrations of silver in the water and sediment compartments, as well as in C. riparius tissue, in the presence and absence of sulfide. Finally, in order to investigate how sulfide and DOM affect the release of ions from AgNPs, we also monitored released Ag<SUP>+</SUP> in each treatment. In the presence of sulfide, AgNPs were found to be less toxic to C. riparius in acute and chronic endpoints than AgNPs alone, whereas DOM treatment did not modulate the toxicity of AgNPs. Sulfide treatment reduced the release of Ag<SUP>+</SUP> from AgNPs. Water-spiked AgNPs with sulfide were found to be more slowly incorporated into both sediment and larvae as compared to the AgNP alone. Overall, the results suggest that the presence of sulfide in sediment mitigates the ecotoxicity of AgNPs in C. riparius.

Application of MoS₂ modified screen-printed electrodes for highly sensitive detection of bovine serum albumin

Kukkar, M.,Sharma, A.,Kumar, P.,Kim, K.H.,Deep, A. Elsevier Pub. Co 2016 Analytica chimica acta Vol.939 No.-

The present work reports the application of a new molybdenum disulphide (MoS<SUB>2</SUB>)-based electrochemical platform for highly sensitive quantitation of an iron-binding protein, bovine serum albumin (BSA). The gold screen-printed electrodes were modified with MoS<SUB>2</SUB> nanoflakes, followed by bioconjugation with anti-BSA antibodies. Using the above bioelectrode, cyclic voltammetric analysis was carried out in the presence of a Fe<SUP>3+</SUP>/Fe<SUP>2+</SUP> redox probe which exhibited a linear response of peak current with varying concentrations of BSA up to 10 ng/mL (with a detection limit of 0.006 ng/mL). This study is novel in that it shows a considerable enhancement of signal during electrochemical sensing of a protein.

Staring at protein-surfactant interactions: Fundamental approaches and comparative evaluation of their combinations - A review

Li, Yan,Lee, Jae-Seung Elsevier Pub. Co 2019 Analytica Chimica Acta Vol.1063 No.-

<P><B>Abstract</B></P> <P>Protein-surfactant interactions have been explored for decades owing to their widespread application in the pharmaceutical, food, and cosmetics industries and their importance to biochemical systems. However, they require further study owing to their compositional complexity and the innate limitations of current analytical approaches. In this review, we briefly introduce a series of individual approaches used for the qualitative and quantitative investigation of protein-surfactant interactions, including absorbance- or emission-based spectroscopy, scattering-based spectroscopy, mass spectrometry, calorimetry, computation and microscopy. More importantly, we then compare and evaluate various combinations of these approaches and provide comprehensive critical assessments and comments regarding their application to the advanced study of protein-surfactant interactions at the molecular level.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Investigation of protein-surfactant interactions are important in chemistry. </LI> <LI> Individual analytical approaches have limitations. </LI> <LI> Overview of individual analytical approaches: cons and pros. </LI> <LI> Combinations of current individual approaches to overcome their limitations. </LI> <LI> Assessment of the efficiency and validity of combinations of analytical approaches. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Remediation of petroleum hydrocarbon-contaminated sites by DNA diagnosis-based bioslurping technology

Kim, S.,Krajmalnik-Brown, R.,Kim, J.O.,Chung, J. Elsevier Pub.Co 2014 Science of the Total Environment Vol.497 No.-

The application of effective remediation technologies can benefit from adequate preliminary testing, such as in lab-scale and Pilot-scale systems. Bioremediation technologies have demonstrated tremendous potential with regards to cost, but they cannot be used for all contaminated sites due to limitations in biological activity. The purpose of this study was to develop a DNA diagnostic method that reduces the time to select contaminated sites that are good candidates for bioremediation. We applied an oligonucleotide microarray method to detect and monitor genes that lead to aliphatic and aromatic degradation. Further, the bioremediation of a contaminated site, selected based on the results of the genetic diagnostic method, was achieved successfully by applying bioslurping in field tests. This gene-based diagnostic technique is a powerful tool to evaluate the potential for bioremediation in petroleum hydrocarbon contaminated soil.

Hypersensitive electrochemical immunoassays based on highly N-doped silicon carbide (SiC) electrode

Park, Jun-Hee,Song, Zhiquan,Lee, Ga-Yeon,Jeong, Seong-Min,Kang, Min-Jung,Pyun, Jae-Chul Elsevier Pub. Co 2019 Analytica chimica acta Vol.1073 No.-

<P><B>Abstract</B></P> <P>Highly N-doped SiC was presented as an optimal electrode for electrochemical immunoassays with a far higher sensitivity than chemiluminescence detection. As the first step, the electrochemical properties of highly N-doped SiC, such as the double-layer capacitance (C<SUB>dl</SUB>), rate constant for electron transfer (k<SUB>app</SUB>) and ideal polarizable potential range (electrochemical window) were analyzed and compared with those of Au, Pt, and graphite electrodes. The highly N-doped SiC electrode was used for the quantification of oxidized 3,3′,5,5′-tetramethylbenzidine (TMB) which was widely used as chromogenic substrate for commercialized immunoassay kits. In order to enhance the sensitivity for the quantification of the oxidized TMB the chronoamperometry was applied to avoid the background current of i-V measurement. Finally, the chronoamperometry based on the highly N-doped SiC electrode was applied to commercial immunoassay kits for the medical diagnosis of the human immunodeficiency virus (HIV) and the human hepatitis B surface antigen (hHBsAg). The chronoamperometric measurement based on the highly N-doped SiC electrode was proved to detect at far lower limits in comparison with the conventional optical density measurement as well as the chemiluminescence assay based on luminol as a chemiluminescent probe.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hyper sensitive immunoassay with a far higher sensitivity than chemiluminescnece was made by using SiC electrode. </LI> <LI> SiC electrode for chronoamperometry was made by using a highly N-doped SiC wafer. </LI> <LI> Electrochemical properties of SiC electrode were analyzed, such as C<SUB>dl</SUB>, K<SUB>app</SUB>, potential window. </LI> <LI> Hyper sensitive immunoassay with SiC electrode was demonstrated for medical diagnosis of HIV and hHBsAg. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Overview on relative importance of house dust ingestion in human exposure to polybrominated diphenyl ethers (PBDEs): International comparison and Korea as a case

Kim, S.K.,Kim, K.S.,Sang, H.H. Elsevier Pub.Co 2016 The Science of the total environment Vol.571 No.-

Human exposure studies to polybrominated diphenyl ethers (PBDEs) have reached different results about the relative importance of diet intake and house dust ingestion. In the present study, concentrations of PBDEs in Korean house dust (n=15) from geographically different cities were measured, which were in agreement with a previous result, and compared with those for 22 countries of five continents collected from the most recent scientific literature. Compared with other exposure pathways, diet intake was the most important contributor to total PBDEs exposure of Korean adults (i.e., 71% of overall intake). On global comparison, total PBDE levels in house dust differed by two to three orders of magnitude among the countries investigated, with a significant relationship with gross domestic product (GDP). Whereas, dietary daily intakes exhibited a narrow difference within one order of magnitude worldwide and no relationship with GDP. Consequently, the relative importance of major two pathways depended on the contamination extent of PBDEs in house dust, which may be associated with the amount of PBDE products in use. In most countries except for UK and USA, the contribution of house dust ingestion was less important than diet intake in the current and are expected to much more mitigate in the future. However, how fast the effect of regulation will be reflected to house dust and human exposure is necessary to be monitored steadily.