High-performance liquid chromatographic determination of loxoprofen and its diastereomeric alcohol metabolites in biological fluids by fluorescence labelling with 4-bromomethyl-6,7-methylenedioxycoumarin.

PubMed

Naganuma, H; Kawahara, Y

1990-09-14

A simple and sensitive high-performance liquid chromatographic procedure to determine loxoprofen and its diastereomeric alcohol metabolites in biological specimens is described. The analysis involves liquid-liquid extraction with benzene, pre-column derivatization with a highly fluorogenic reagent, 4-bromomethyl-6,7-methylenedioxycoumarin (BrMDC) and subsequent separation on a reversed-phase column. Loxoprofen, its pharmacologically active metabolite, trans-alcohol, and less active cis-alcohol were completely separated within 20 min with a mobile phase of 55% of aqueous acetonitrile containing acetic acid. Any endogenous substances do not interfere in the analysis of either plasma or urine samples. The quantitation limit was 0.01 micrograms/ml for human plasma and 0.05 micrograms/ml for urine. The method was applied to a pharmacokinetic study in healthy human subjects who had received 60 mg of loxoprofen sodium.

High Resolution Displays Using NCAP Liquid Crystals

NASA Astrophysics Data System (ADS)

Macknick, A. Brian; Jones, Phil; White, Larry

1989-07-01

Nematic curvilinear aligned phase (NCAP) liquid crystals have been found useful for high information content video displays. NCAP materials are liquid crystals which have been encapsulated in a polymer matrix and which have a light transmission which is variable with applied electric fields. Because NCAP materials do not require polarizers, their on-state transmission is substantially better than twisted nematic cells. All dimensional tolerances are locked in during the encapsulation process and hence there are no critical sealing or spacing issues. By controlling the polymer/liquid crystal morphology, switching speeds of NCAP materials have been significantly improved over twisted nematic systems. Recent work has combined active matrix addressing with NCAP materials. Active matrices, such as thin film transistors, have given displays of high resolution. The paper will discuss the advantages of NCAP materials specifically designed for operation at video rates on transistor arrays; applications for both backlit and projection displays will be discussed.

Aloe vera Derived Activated High-Surface-Area Carbon for Flexible and High-Energy Supercapacitors.

PubMed

Karnan, M; Subramani, K; Sudhan, N; Ilayaraja, N; Sathish, M

2016-12-28

Materials which possess high specific capacitance in device configuration with low cost are essential for viable application in supercapacitors. Herein, a flexible high-energy supercapacitor device was fabricated using porous activated high-surface-area carbon derived from aloe leaf (Aloe vera) as a precursor. The A. vera derived activated carbon showed mesoporous nature with high specific surface area of ∼1890 m 2 /g. A high specific capacitance of 410 and 306 F/g was achieved in three-electrode and symmetric two-electrode system configurations in aqueous electrolyte, respectively. The fabricated all-solid-state device showed a high specific capacitance of 244 F/g with an energy density of 8.6 Wh/kg. In an ionic liquid electrolyte, the fabricated device showed a high specific capacitance of 126 F/g and a wide potential window up to 3 V, which results in a high energy density of 40 Wh/kg. Furthermore, it was observed that the activation temperature has significant role in the electrochemical performance, as the activated sample at 700 °C showed best activity than the samples activated at 600 and 800 °C. The electron microscopic images (FE-SEM and HR-TEM) confirmed the formation of pores by the chemical activation. A fabricated supercapacitor device in ionic liquid with 3 V could power up a red LED for 30 min upon charging for 20s. Also, it is shown that the operation voltage and capacitance of flexible all-solid-state symmetric supercapacitors fabricated using aloe-derived activated carbon could be easily tuned by series and parallel combinations. The performance of fabricated supercapacitor devices using A. vera derived activated carbon in all-solid-state and ionic liquid indicates their viable applications in flexible devices and energy storage.

33 CFR 154.2201 - Vapor control system-general requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... high liquid level sensor that activates an alarm that satisfies the requirements of 33 CFR 154.2100(e); and (3) A high-high liquid level sensor that closes the remotely operated cargo vapor shutoff valve... vapor-moving device. One sensor with two stages may be used to meet this requirement as well as...

Extraction and Purification of Glucoraphanin by Preparative High-Performance Liquid Chromatography (HPLC)

ERIC Educational Resources Information Center

Lee, Iris; Boyce, Mary C.

2011-01-01

A student activity that focuses on the isolation of glucoraphanin from broccoli using preparative high-performance liquid chromatography (HPLC) is presented here. Glucoraphanin is a glucosinolate, whose byproducts are known to possess anticancer properties. It is present naturally at high levels in broccoli and other "Brassica" vegetables. This…

Process for preparing active oxide powders

DOEpatents

Berard, Michael F.; Hunter, Jr., Orville; Shiers, Loren E.; Dole, Stephen L.; Scheidecker, Ralph W.

1979-02-20

An improved process for preparing active oxide powders in which cation hydroxide gels, prepared in the conventional manner are chemically dried by alternately washing the gels with a liquid organic compound having polar characteristics and a liquid organic compound having nonpolar characteristics until the mechanical water is removed from the gel. The water-free cation hydroxide is then contacted with a final liquid organic wash to remove the previous organic wash and speed drying. The dried hydroxide treated in the conventional manner will form a highly sinterable active oxide powder.

Effects of nicotine-containing and "nicotine-free" e-cigarette refill liquids on intracranial self-stimulation in rats.

PubMed

Harris, Andrew C; Muelken, Peter; Smethells, John R; Yershova, Katrina; Stepanov, Irina; Olson, Thao Tran; Kellar, Kenneth J; LeSage, Mark G

2018-04-01

Animal models are needed to inform FDA regulation of electronic cigarettes (ECs) because they avoid limitations associated with human studies. We previously reported that an EC refill liquid produced less aversive/anhedonic effects at a high nicotine dose than nicotine alone as measured by elevations in intracranial self-stimulation (ICSS) thresholds, which may reflect the presence of behaviorally active non-nicotine constituents (e.g., propylene glycol) in the EC liquids. The primary objective of this study was to assess the generality of our prior ICSS findings to two additional EC liquids. We also compared effects of "nicotine-free" varieties of these EC liquids on ICSS, as well as binding affinity and/or functional activity of nicotine alone, nicotine-containing EC liquids, and "nicotine-free" EC liquids at nicotinic acetylcholine receptors (nAChRs). Nicotine alone and nicotine dose-equivalent concentrations of both nicotine-containing EC liquids produced similar lowering of ICSS thresholds at low to moderate nicotine doses, indicating similar reinforcement-enhancing effects. At high nicotine doses, nicotine alone elevated ICSS thresholds (a measure of anhedonia-like behavior) while the EC liquids did not. Nicotine-containing EC liquids did not differ from nicotine alone in terms of binding affinity or functional activity at nAChRs. "Nicotine-free" EC liquids did not affect ICSS, but bound with low affinity at some (e.g., α4ß2) nAChRs. These findings suggest that non-nicotine constituents in these EC liquids do not contribute to their reinforcement-enhancing effects. However, they may attenuate nicotine's acute aversive/anhedonic and/or toxic effects, which may moderate the abuse liability and/or toxicity of ECs. Copyright © 2018 Elsevier B.V. All rights reserved.

Liquid metal heat sink for high-power laser diodes

NASA Astrophysics Data System (ADS)

Vetrovec, John; Litt, Amardeep S.; Copeland, Drew A.; Junghans, Jeremy; Durkee, Roger

2013-02-01

We report on the development of a novel, ultra-low thermal resistance active heat sink (AHS) for thermal management of high-power laser diodes (HPLD) and other electronic and photonic components. AHS uses a liquid metal coolant flowing at high speed in a miniature closed and sealed loop. The liquid metal coolant receives waste heat from an HPLD at high flux and transfers it at much reduced flux to environment, primary coolant fluid, heat pipe, or structure. Liquid metal flow is maintained electromagnetically without any moving parts. Velocity of liquid metal flow can be controlled electronically, thus allowing for temperature control of HPLD wavelength. This feature also enables operation at a stable wavelength over a broad range of ambient conditions. Results from testing an HPLD cooled by AHS are presented.

Frequency modulation detection atomic force microscopy in the liquid environment

NASA Astrophysics Data System (ADS)

Jarvis, S. P.; Ishida, T.; Uchihashi, T.; Nakayama, Y.; Tokumoto, H.

True atomic resolution imaging using frequency modulation detection is already well established in ultra-high vacuum. In this paper we demonstrate that it also has great potential in the liquid environment. Using a combination of magnetic activation and high-aspect-ratio carbon nanotube probes, we show that imaging can be readily combined with point spectroscopy, revealing both the tip-sample interaction and the structure of the intermediate liquid.

Luminosity limits for liquid argon calorimetry

NASA Astrophysics Data System (ADS)

J, Rutherfoord; B, Walker R.

2012-12-01

We have irradiated liquid argon ionization chambers with betas using high-activity Strontium-90 sources. The radiation environment is comparable to that in the liquid argon calorimeters which are part of the ATLAS detector installed at CERN's Large Hadron Collider. We measure the ionization current over a wide range of applied potential for two different source activities and for three different chamber gaps. These studies provide operating experience at exceptionally high ionization rates. We can operate these chambers either in the normal mode or in the space-charge limited regime and thereby determine the transition point between the two. From the transition point we indirectly extract the positive argon ion mobility.

Liquid-liquid phase separation of freely falling undercooled ternary Fe-Cu-Sn alloy

NASA Astrophysics Data System (ADS)

Wang, W. L.; Wu, Y. H.; Li, L. H.; Zhai, W.; Zhang, X. M.; Wei, B.

2015-11-01

The active modulation and control of the liquid phase separation for high-temperature metallic systems are still challenging the development of advanced immiscible alloys. Here we present an attempt to manipulate the dynamic process of liquid-liquid phase separation for ternary Fe47.5Cu47.5Sn5 alloy. It was firstly dispersed into numerous droplets with 66 ~ 810 μm diameters and then highly undercooled and rapidly solidified under the containerless microgravity condition inside drop tube. 3-D phase field simulation was performed to explore the kinetic evolution of liquid phase separation. Through regulating the combined effects of undercooling level, phase separation time and Marangoni migration, three types of separation patterns were yielded: monotectic cell, core shell and dispersive structures. The two-layer core-shell morphology proved to be the most stable separation configuration owing to its lowest chemical potential. Whereas the monotectic cell and dispersive microstructures were both thermodynamically metastable transition states because of their highly active energy. The Sn solute partition profiles of Fe-rich core and Cu-rich shell in core-shell structures varied only slightly with cooling rate.

Liquid Quinones for Solvent-Free Redox Flow Batteries.

PubMed

Shimizu, Akihiro; Takenaka, Keisuke; Handa, Naoyuki; Nokami, Toshiki; Itoh, Toshiyuki; Yoshida, Jun-Ichi

2017-11-01

Liquid benzoquinone and naphthoquinone having diethylene glycol monomethyl ether groups are designed and synthesized as redox active materials that dissolve supporting electrolytes. The Li-ion batteries based on the liquid quinones using LiBF 4 /PC show good performance in terms of voltage, capacity, energy efficiency, and cyclability in both static and flow modes. A battery is constructed without using intentionally added organic solvent, and its high energy density (264 W h L -1 ) demonstrates the potential of solvent-free organic redox flow batteries using liquid active materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-pressure liquid-monopropellant strand combustion.

NASA Technical Reports Server (NTRS)

Faeth, G. M.

1972-01-01

Examination of the influence of dissolved gases on the state of the liquid surface during high-pressure liquid-monopropellant combustion through the use of a strand burning experiment. Liquid surface temperatures were measured, using fine-wire thermocouples, during the strand combustion of ethyl nitrate, normal propyl nitrate, and propylene glycol dinitrate at pressures up to 81 atm. These measurements were compared with the predictions of a variable-property gas-phase analysis assuming an infinite activation energy for the decomposition reaction. The state of the liquid surface was estimated using a conventional low-pressure phase equilibrium model, as well as a high-pressure version that considered the presence of dissolved combustion-product gases in the liquid phase. The high-pressure model was found to give a superior prediction of measured liquid surface temperatures. Computed total pressures required for the surface to reach its critical mixing point during strand combustion were found to be in the range from 2.15 to 4.62 times the critical pressure of the pure propellant. Computed dissolved gas concentrations at the liquid surface were in the range from 35 to 50% near the critical combustion condition.

Method of making electrodes for electrochemical cell. [Li-Al alloy

DOEpatents

Kaun, T.D.; Kilsdonk, D.J.

1981-07-29

A method is described for making an electrode for an electrochemical cell in which particulate electrode-active material is mixed with a liquid organic carrier chemically inert with respect to the electrode-active material, mixing the liquid carrier to form an extrudable slurry. The liquid carrier is present in an amount of from about 10 to about 50% by volume of the slurry, and then the carrier is removed from the slurry leaving the electrode-active material. The method is particularly suited for making a lithium-aluminum alloy negative electrode for a high-temperature cell.

Rapid screening, identification, and purification of neuraminidase inhibitors from Lithospermum erythrorhizon Sieb.et Zucc. by ultrafiltration with HPLC-ESI-TOF-MS combined with semipreparative HPLC.

PubMed

Zhang, Minmin; Zhao, Hengqiang; Zhao, Zhiguo; Yan, Huijiao; Lv, Ruimin; Cui, Li; Yuan, Jinpeng; Wang, Daijie; Geng, Yanling; Liu, Daicheng; Wang, Xiao

2016-06-01

We put forward an efficient strategy based on bioassay guidance for the rapid screening, identification, and purification of the neuraminidase inhibitors from traditional Chinese medicines, and apply to the discovery of anti-influenza components from Lithospermiun erythrorhizon Sieb.et Zucc. Ultrafiltration with high-performance liquid chromatography and electrospray ionization time-of-flight mass spectrometry was employed for the rapid screening and preliminarily identification of anti-influenza components from Zicao. Semipreparative high-performance liquid chromatography was used for the rapid separation and purification of the target compounds. NMR spectroscopy, mass spectrometry, and UV spectroscopy were used for further structural identification, and the activity of the compounds was verified by in vitro assay. Five compounds were found to have neuraminidase inhibitory activity by this method. Subsequently, the five compounds were separated by semipreparative high-performance liquid chromatography with the purity over 98% for all of them by high-performance liquid chromatography test. Combined with the NMR spectroscopy, mass spectrometry, and UV spectroscopy data, they were identified as alkannin, acetylalkannin, isobutyrylalkannin, β,β-dimethylacryloylalkannin and isovalerylalkannin. The in vitro assay showed that all five compounds had good neuraminidase inhibitory activities. These results suggested that the method is highly efficient, and it can provide platform and methodology supports for the rapid discovery of anti-influenza active ingredients from complex Chinese herbal medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Per F.

A high-temperature containment-isolation system for transferring heat from a nuclear reactor containment to a high-pressure heat exchanger is presented. The system uses a high-temperature, low-volatility liquid coolant such as a molten salt or a liquid metal, where the coolant flow path provides liquid free surfaces a short distance from the containment penetrations for the reactor hot-leg and the cold-leg, where these liquid free surfaces have a cover gas maintained at a nearly constant pressure and thus prevent high-pressures from being transmitted into the reactor containment, and where the reactor vessel is suspended within a reactor cavity with a plurality ofmore » refractory insulator blocks disposed between an actively cooled inner cavity liner and the reactor vessel.« less

Lightning under water: Diverse reactive environments and evidence of synergistic effects for material treatment and activation

NASA Astrophysics Data System (ADS)

Levchenko, Igor; Bazaka, Kateryna; Baranov, Oleg; Sankaran, R. Mohan; Nomine, Alexandre; Belmonte, Thierry; Xu, Shuyan

2018-06-01

This focused review aims to reveal and illustrate some unique features of processes triggered by high-density energy applied to liquids and gas-liquid interfaces and to highlight a wide spectrum of their technological applications capable of producing various advantageous effects, ranging from nanosynthesis to biological and medical applications. Plasma, electric discharges, laser, and ultrasound power effects were selected as representative examples of high-density energy and liquid interactions, yet the available possibilities are not limited by these quite different types of power and thus the reader could extrapolate the outlined features and effects to other kinds of powerful impacts. The basic physical mechanisms are briefly reviewed with the aim to familiarize the readers with the potential capabilities of high-density energy processes in liquids. These will be of direct interest to researchers tasked with the development, optimization, and characterization of processes and highly reactive environments for highly controlled transformation of matter in abiotic and biological systems. It could also be highly useful for under- and post-graduate students specializing in the related fields and general physical audience involved in various plasma, materials, energy conversion, and other concurrent research activities.

Study of Separation and Identification of the Active Ingredients in Gardenia jasminoides Ellis Based on a Two-Dimensional Liquid Chromatography by Coupling Reversed Phase Liquid Chromatography and Hydrophilic Interaction Liquid Chromatography.

PubMed

Zhou, Xuan; Chen, Cen; Ye, Xiaolan; Song, Fenyun; Fan, Guorong; Wu, Fuhai

2017-01-01

In this paper, by coupling reversed phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC), a two-dimensional liquid chromatography system was developed for separation and identification of the active ingredients in Gardenia jasminoides Ellis (GJE). By applying the semi-preparative C18 column as the first dimension and the core-shell column as the second dimension, a total of 896 peaks of GJE were separated. Among the 896 peaks, 16 active ingredients including geniposide, gardenoside, gardoside, etc. were identified by mass spectrometry analysis. The results indicated that the proposed two-dimensional RPLC/HILIC system was an effective method for the analysis of GJE and might hold a high potential to become a useful tool for analysis of other complex mixtures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Liquid cooled approaches for high density avionics

NASA Astrophysics Data System (ADS)

Levasseur, Robert

Next-generation aircraft will require avionics that provide greater system performance in a smaller volume, a process that requires highly developed thermal management techniques. To meet this need, a liquid-cooled approach has been developed to replace the conventional air-cooled approach for high-power applications. Liquid-cooled chassis and flow-through modules have been developed to limit junction temperatures to acceptable levels. Liquid cooling also permits emergency operation after loss of coolant for longer time intervals, which is desirable for flight-critical airborne applications. Activity to date has emphasized the development of chassis and modules that support the US Department of Defense's (DoD) two-level maintenance initiative as governed by the Joint Integrated Avionics Working Group (JIAWG).

Aligned Carbon Nanotubes for Highly Efficient Energy Generation and Storage Devices

DTIC Science & Technology

2012-01-24

solution processing methods, including filtration, solution-casting, electrophoretic deposition, and Langmuir - Blodgett deposition. However, most...supercapacitors with environmentally friendly ionic liquid electrolytes. These new nanocomposite electrodes consist of the high-surface-area activated...carbons, carbon nanotubes, and ionic liquids as the integrated constituent components. The resultant composites show significantly improved charge

Oxygen reduction reaction properties of nitrogen-incorporated nanographenes synthesized using in-liquid plasma from mixture of ethanol and iron phthalocyanine

NASA Astrophysics Data System (ADS)

Amano, Tomoki; Kondo, Hiroki; Takeda, Keigo; Ishikawa, Kenji; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

2018-04-01

Nanographenes were synthesized using in-liquid plasma from a mixture of iron phthalocyanine and ethanol. In a previous study, micrometer-scale flakes with nitrogen incorporation were obtained. A nonprecious metal catalytic activity was observed with 3.13 electrons in an oxygen reduction reaction under an acidic solute condition. Large-surface-area, high-graphene-crystallinity, and iron-carbon-bonding sites were found owing to a high catalytic activity in Fe-N/nanographene.

[Separation and identification of bovine lactoferricin by high performance liquid chromatography-matrix-assisted laser desorption/ionization time of flight/ time of flight mass spectrometry].

PubMed

An, Meichen; Liu, Ning

2010-02-01

A high performance liquid chromatography-matrix-assisted laser desorption/ionization time of flight/time of flight mass spectrometry (HPLC-MALDI-TOF/TOF MS) method was developed for the separation and identification of bovine lactoferricin (LfcinB). Bovine lactoferrin was hydrolyzed by pepsin and then separated by ion exchange chromatography and reversed-phase liquid chromatography (RP-LC). The antibacterial activities of the fractions from RP-LC separation were determined and the protein concentration of the fraction with the highest activity was measured, whose sequence was indentified by MALDI-TOF/TOF MS. The relative molecular mass of LfcinB was 3 124.89 and the protein concentration was 18.20 microg/mL. The method of producing LfcinB proposed in this study has fast speed, high accuracy and high resolution.

Influence of barrier on partial discharge activity by a conducting particle in liquid nitrogen under AC voltages adopting UHF technique

NASA Astrophysics Data System (ADS)

Sarathi, R.; Giridhar, A. V.; Sethupathi, K.

2011-02-01

The UHF signals are generated due to PD formed by particle movement in liquid nitrogen under AC voltages. The levitation voltage of a particle in liquid nitrogen measured through UHF technique and by conventional PD measurement technique is the same, confirming the sensitivity of UHF technique for identification of PD activity. The frequency content of UHF signal generated due to particle movement in liquid nitrogen, under AC voltages, lies in the range 0.5-1.5 GHz. The characteristics of UHF signal generated due to particle movement between the barrier and high voltage/ground electrode is much similar to the signal generated by particle movement in clean electrode gap. Pseudo resonance phenomena can occur in liquid nitrogen due to particle movement. It is also observed that the partial discharge magnitude, in general, be high when the particle moves between the barrier and high voltage electrode when compared to the barrier and the ground electrode. Percentage of clay in epoxy nanocomposites has not altered the levitation voltage of the particle in the electrode gap. Zero span analysis clearly indicates that pseudo resonance occurs when particle moves (in a short gap) between the barrier and high voltage/ground electrode.

Measurement of tritium in natural water

NASA Astrophysics Data System (ADS)

Li, Meifen

1985-06-01

A detergent-scintillation liquid mixture applied to measure low specific activity of tritium in natural water was studied. The DYS-1 low level liquid scintillation counter designed and manufactured by our institute was employed. In comparing the Triton X-100 scintillation liquid mixture with the dioxane-based-scintillation liquid, a better formula for Triton X-100 scintillation liquid mixture was determined, the mixture possesses the quality of high water content; high efficiency and low back-ground in measuring tritium in water. Chemiluminescence of the Triton X-100 scintillation liquid mixture can be totally de-excited in short time. It can be employed at ambient temperature 11 28°C. For 20ml sample in quartz vials, counting efficiency is 15% with a background 2.17 cpm, Y=31 TU (t=30 min).

Correlation between Fragility and the Arrhenius Crossover Phenomenon in Metallic, Molecular, and Network Liquids.

PubMed

Jaiswal, Abhishek; Egami, Takeshi; Kelton, K F; Schweizer, Kenneth S; Zhang, Yang

2016-11-11

We report the observation of a distinct correlation between the kinetic fragility index m and the reduced Arrhenius crossover temperature θ_{A}=T_{A}/T_{g} in various glass-forming liquids, identifying three distinguishable groups. In particular, for 11 glass-forming metallic liquids, we universally observe a crossover in the mean diffusion coefficient from high-temperature Arrhenius to low-temperature super-Arrhenius behavior at approximately θ_{A}≈2 which is in the stable liquid phases. In contrast, for fragile molecular liquids, this crossover occurs at much lower θ_{A}≈1.4 and usually in their supercooled states. The θ_{A} values for strong network liquids spans a wide range higher than 2. Intriguingly, the high-temperature activation barrier E_{∞} is universally found to be ∼11k_{B}T_{g} and uncorrelated with the fragility or the reduced crossover temperature θ_{A} for metallic and molecular liquids. These observations provide a way to estimate the low-temperature glassy characteristics (T_{g} and m) from the high-temperature liquid quantities (E_{∞} and θ_{A}).

Correlation between Fragility and the Arrhenius Crossover Phenomenon in Metallic, Molecular, and Network Liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaiswal, Abhishek; Egami, Takeshi; Kelton, K. F.

2016-11-10

In this paper, we report the observation of a distinct correlation between the kinetic fragility index m and the reduced Arrhenius crossover temperature θ A = T A/T g in various glass-forming liquids, identifying three distinguishable groups. In particular, for 11 glass-forming metallic liquids, we universally observe a crossover in the mean diffusion coefficient from high-temperature Arrhenius to low-temperature super-Arrhenius behavior at approximately θ A ≈ 2 which is in the stable liquid phases. In contrast, for fragile molecular liquids, this crossover occurs at much lower θ A ≈ 1.4 and usually in their supercooled states. The θ A valuesmore » for strong network liquids spans a wide range higher than 2. Intriguingly, the high-temperature activation barrier E ∞ is universally found to be ~11k BT g and uncorrelated with the fragility or the reduced crossover temperature θ A for metallic and molecular liquids. Finally, these observations provide a way to estimate the low-temperature glassy characteristics (T g and m) from the high-temperature liquid quantities (E ∞ and θ A).« less

A solvated electron lithium electrode for secondary batteries

NASA Astrophysics Data System (ADS)

Sammells, A. F.; Semkow, K. W.

1986-09-01

Attention is given to a novel method for the achievement of high electro-chemical reversibility in Li-based nonaqueous cells, using a liquid negative electrode that consists of Li dissolved in liquid ammonia as a solvated electron Li electrode. The containment of this liquid negative active material from direct contact to a liquid nonaqueous electrolyte in the positive electrode compartment was realized through the use of a Li-intercalated, electronically conducting ceramic membrane.

Device for measuring oxygen activity in liquid sodium

DOEpatents

Roy, P.; Young, R.S.

1973-12-01

A composite ceramic electrolyte in a configuration (such as a closed end tube or a plate) suitable to separate liquid sodium from a reference electrode with a high impedance voltmeter connected to measure EMF between the sodium and the reference electrode as a measure of oxygen activity in the sodium is described. The composite electrolyte consists of zirconiacalcia with a bonded layer of thoria-yttria. The device is used with a gaseous reference electrode on the zirconia-calcia side and liquid sodium on the thoria-yttria side of the electrolyte. (Official Gazette)

Simultaneous Determination of Caffeine and Vitamin B6 in Energy Drinks by High-Performance Liquid Chromatography (HPLC)

ERIC Educational Resources Information Center

Leacock, Rachel E.; Stankus, John J.; Davis, Julian M.

2011-01-01

A high-performance liquid chromatography experiment to determine the concentration of caffeine and vitamin B6 in sports energy drinks has been developed. This laboratory activity, which is appropriate for an upper-level instrumental analysis course, illustrates the standard addition method and simultaneous determination of two species. (Contains 1…

The effects of high concentrations of ionic liquid on GB1 protein structure and dynamics probed by high-resolution magic-angle-spinning NMR spectroscopy.

PubMed

Warner, Lisa; Gjersing, Erica; Follett, Shelby E; Elliott, K Wade; Dzyuba, Sergei V; Varga, Krisztina

2016-12-01

Ionic liquids have great potential in biological applications and biocatalysis, as some ionic liquids can stabilize proteins and enhance enzyme activity, while others have the opposite effect. However, on the molecular level, probing ionic liquid interactions with proteins, especially in solutions containing high concentration of ionic liquids, has been challenging. In the present work the 13 C, 15 N-enriched GB1 model protein was used to demonstrate applicability of high-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy to investigate ionic liquid - protein interactions. Effect of an ionic liquid (1-butyl-3-methylimidazolium bromide, [C 4 -mim]Br) on GB1was studied over a wide range of the ionic liquid concentrations (0.6 to 3.5 M, which corresponds to 10%-60% v/v). Interactions between GB1 and [C 4 -mim]Br were observed from changes in the chemical shifts of the protein backbone as well as the changes in 15 N ps-ns dynamics and rotational correlation times. Site-specific interactions between the protein and [C 4 -mim]Br were assigned using 3D methods under HR-MAS conditions. Thus, HR-MAS NMR is a viable tool that could aid in elucidation of the molecular mechanism of ionic liquid - protein interactions.

Wearable Wide-Range Strain Sensors Based on Ionic Liquids and Monitoring of Human Activities

PubMed Central

Zhang, Shao-Hui; Wang, Feng-Xia; Li, Jia-Jia; Peng, Hong-Dan; Yan, Jing-Hui; Pan, Ge-Bo

2017-01-01

Wearable sensors for detection of human activities have encouraged the development of highly elastic sensors. In particular, to capture subtle and large-scale body motion, stretchable and wide-range strain sensors are highly desired, but still a challenge. Herein, a highly stretchable and transparent stain sensor based on ionic liquids and elastic polymer has been developed. The as-obtained sensor exhibits impressive stretchability with wide-range strain (from 0.1% to 400%), good bending properties and high sensitivity, whose gauge factor can reach 7.9. Importantly, the sensors show excellent biological compatibility and succeed in monitoring the diverse human activities ranging from the complex large-scale multidimensional motions to subtle signals, including wrist, finger and elbow joint bending, finger touch, breath, speech, swallow behavior and pulse wave. PMID:29135928

Recent applications of hydrophilic interaction liquid chromatography in pharmaceutical analysis.

PubMed

Zhang, Qian; Yang, Feng-Qing; Ge, Liya; Hu, Yuan-Jia; Xia, Zhi-Ning

2017-01-01

Hydrophilic interaction liquid chromatography, an alternative liquid chromatography mode, is of particular interest in separating hydrophilic and polar ionic compounds. Compared with traditional liquid chromatography techniques, hydrophilic interaction liquid chromatography offers specific advantages mainly including: (1) relatively green and water-soluble mobile phase composition, which enhances the solubility of hydrophilic and polar ionic compounds; (2) no need for ion-pairing reagents and high content of organic solvent, which benefits mass spectrometry detection; (3) high orthogonality to reverse-phase liquid chromatography, well adapted to two-dimensional liquid chromatography for complicated samples. Therefore, hydrophilic interaction liquid chromatography has been rapidly developed in many areas over the past decades. This review summarizes the recent progress (from 2012 to July 2016) of hydrophilic interaction liquid chromatography in pharmaceutical analysis, with the focus on detecting chemical drugs in various matrices, charactering active compounds of natural products and assessing biotherapeutics through typical structure unit. Moreover, the retention mechanism and behavior of analytes in hydrophilic interaction liquid chromatography as well as some novel hydrophilic interaction liquid chromatography columns used for pharmaceutical analysis are also described. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antifungal activity of ionic liquids based on (-)-menthol: a mechanism study.

PubMed

Suchodolski, Jakub; Feder-Kubis, Joanna; Krasowska, Anna

2017-04-01

The mechanism of toxicity of chiral ionic liquids with (1R,2S,5R)-(-)-menthol [C n -Am-Men][Cl] (n=10, 11 or 12) in the fungus Candida albicans is reported here. Ionic liquids were more toxic towards Candida strain lacking all identified multidrug resistance efflux pumps. Moreover, the compounds tested inhibited C. albicans filamentation at the concentration at which detached fungal cells also adhered to the plastic surface. Our results showed the high activity of all the tested chiral ionic liquids in the permeabilization of C. albicans' membranes and in the digestion and interruption of the cell wall. The investigated ionic liquids thus have potential as disinfectants because besides their antifungal and antiadhesive action these compounds do not cause hemolysis. Copyright © 2017 Elsevier GmbH. All rights reserved.

Mesoscopic simulations of shock-to-detonation transition in reactive liquid high explosive

NASA Astrophysics Data System (ADS)

Maillet, J. B.; Bourasseau, E.; Desbiens, N.; Vallverdu, G.; Stoltz, G.

2011-12-01

An extension of the model described in a previous work (see Maillet J. B. et al., EPL, 78 (2007) 68001) based on Dissipative Particle Dynamics is presented and applied to a liquid high explosive (HE), with thermodynamic properties mimicking those of liquid nitromethane. Large scale nonequilibrium simulations of reacting liquid HE with model kinetic under sustained shock conditions allow a better understanding of the shock-to-detonation transition in homogeneous explosives. Moreover, the propagation of the reactive wave appears discontinuous since ignition points in the shocked material can be activated by the compressive waves emitted from the onset of chemical reactions.

Liquid level detector

DOEpatents

Grasso, A.P.

1984-02-21

A liquid level detector for low pressure boilers. A boiler tank, from which vapor, such as steam, normally exits via a main vent, is provided with a vertical side tube connected to the tank at the desired low liquid level. When the liquid level falls to the level of the side tube vapor escapes therethrough causing heating of a temperature sensitive device located in the side tube, which, for example, may activate a liquid supply means for adding liquid to the boiler tank. High liquid level in the boiler tank blocks entry of vapor into the side tube, allowing the temperature sensitive device to cool, for example, to ambient temperature.

Liquid level detector

DOEpatents

Grasso, Albert P.

1986-01-01

A liquid level detector for low pressure boilers. A boiler tank, from which apor, such as steam, normally exits via a main vent, is provided with a vertical side tube connected to the tank at the desired low liquid level. When the liquid level falls to the level of the side tube vapor escapes therethrough causing heating of a temperature sensitive device located in the side tube, which, for example, may activate a liquid supply means for adding liquid to the boiler tank. High liquid level in the boiler tank blocks entry of vapor into the side tube, allowing the temperature sensitive device to cool, for example, to ambient temperature.

Chemical synthesis of biologically active tat trans-activating protein of human immunodeficiency virus type 1.

PubMed Central

Chun, R; Glabe, C G; Fan, H

1990-01-01

Full-length (86-residue) polypeptide corresponding to the human immunodeficiency virus type 1 tat trans-activating protein was chemically synthesized on a semiautomated apparatus, using an Fmoc amino acid continuous-flow strategy. The bulk material was relatively homogeneous, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing, and it showed trans-activating activity when scrape loaded into cells containing a human immunodeficiency virus long terminal repeat-chloramphenicol acetyl-transferase reporter plasmid. Reverse-phase high-pressure liquid chromatography yielded a rather broad elution profile, and assays across the column for biological activity indicated a sharper peak. Thus, high-pressure liquid chromatography provided for enrichment of biological activity. Fast atom bombardment-mass spectrometry of tryptic digests of synthetic tat identified several of the predicted tryptic peptides, consistent with accurate chemical synthesis. Images PMID:2186178

Surface-bonded ionic liquid stationary phases in high-performance liquid chromatography--a review.

PubMed

Pino, Verónica; Afonso, Ana M

2012-02-10

Ionic liquids (ILs) are a class of ionic, nonmolecular solvents which remain in liquid state at temperatures below 100°C. ILs possess a variety of properties including low to negligible vapor pressure, high thermal stability, miscibility with water or a variety of organic solvents, and variable viscosity. IL-modified silica as novel high-performance liquid chromatography (HPLC) stationary phases have attracted considerable attention for their differential behavior and low free-silanol activity. Indeed, around 21 surface-confined ionic liquids (SCIL) stationary phases have been developed in the last six years. Their chromatographic behavior has been studied, and, despite the presence of a positive charge on the stationary phase, they showed considerable promise for the separation of neutral solutes (not only basic analytes), when operated in reversed phase mode. This aspect points to the potential for truly multimodal stationary phases. This review attempts to summarize the state-of-the-art about SCIL phases including their preparation, chromatographic behavior, and analytical performance. Copyright © 2011 Elsevier B.V. All rights reserved.

Earth-like aqueous debris-flow activity on Mars at high orbital obliquity in the last million years

PubMed Central

de Haas, T.; Hauber, E.; Conway, S. J.; van Steijn, H.; Johnsson, A.; Kleinhans, M. G.

2015-01-01

Liquid water is currently extremely rare on Mars, but was more abundant during periods of high obliquity in the last few millions of years. This is testified by the widespread occurrence of mid-latitude gullies: small catchment-fan systems. However, there are no direct estimates of the amount and frequency of liquid water generation during these periods. Here we determine debris-flow size, frequency and associated water volumes in Istok crater, and show that debris flows occurred at Earth-like frequencies during high-obliquity periods in the last million years on Mars. Results further imply that local accumulations of snow/ice within gullies were much more voluminous than currently predicted; melting must have yielded centimetres of liquid water in catchments; and recent aqueous activity in some mid-latitude craters was much more frequent than previously anticipated. PMID:26102485

Melting properties of Pt and its transport coefficients in liquid states under high pressures

NASA Astrophysics Data System (ADS)

Wang, Pan-Pan; Shao, Ju-Xiang; Cao, Qi-Long

2016-11-01

Molecular dynamics (MD) simulations of the melting and transport properties in liquid states of platinum for the pressure range (50-200 GPa) are reported. The melting curve of platinum is consistent with previous ab initio MD simulation results and the first-principles melting curve. Calculated results for the pressure dependence of fusion entropy and fusion volume show that the fusion entropy and the fusion volume decrease with increasing pressure, and the ratio of the fusion volume to fusion entropy roughly reproduces the melting slope, which has a moderate decrease along the melting line. The Arrhenius law well describes the temperature dependence of self-diffusion coefficients and viscosity under high pressure, and the diffusion activation energy decreases with increasing pressure, while the viscosity activation energy increases with increasing pressure. In addition, the entropy-scaling law, proposed by Rosenfeld under ambient pressure, still holds well for liquid Pt under high pressure conditions.

Outstanding features of alginate-based gel electrolyte with ionic liquid for electric double layer capacitors

NASA Astrophysics Data System (ADS)

Soeda, Kazunari; Yamagata, Masaki; Ishikawa, Masashi

2015-04-01

An alginate-based gel electrolyte with an ionic liquid (Alg/IL) is investigated for electric double-layer capacitors (EDLCs) by using physicochemical and electrochemical measurements. The Alg/EMImBF4 (EMImBF4 = 1-ethyl-3-methylimidazolium tetrafluoroborate) gel electrolyte is thermally stable up to 280 °C, where EMImBF4 decomposes. Furthermore, the EDLC with the gel electrolyte can be operated even at high temperature. The cell containing Alg/EMImBF4 is also electrochemically stable even under high voltage (∼3.5 V) operation. Thus, the alginate is a suitable host polymer for the gel electrolyte for EDLCs. According to the result of charge-discharge characteristics, the voltage drop in the charge-discharge curve for the cell with Alg/EMImBF4 gel electrolyte is considerably smaller than that with liquid-phase EMImBF4 electrolyte. To clarify the effect of Alg in contact with the activated carbon electrode, we also prepared an Alg-containing ACFC electrode (Alg + ACFC), and evaluated its EDLC characteristics in liquid EMImBF4. The results prove that the presence of Alg close to the active materials significantly reduces the internal resistance of the EDLC cell, which may be attributed to the high affinity of Alg to activated carbon.

Influence of fermentation liquid from waste activated sludge on anoxic/oxic- membrane bioreactor performance: Nitrogen removal, membrane fouling and microbial community.

PubMed

Han, Xiaomeng; Zhou, Zhen; Mei, Xiaojie; Ma, Yan; Xie, Zhenfang

2018-02-01

In order to investigate effects of waste activated sludge (WAS) fermentation liquid on anoxic/oxic- membrane bioreactor (A/O-MBR), two A/O-MBRs with and without WAS fermentation liquid addition were operated in parallel. Results show that addition of WAS fermentation liquid clearly improved denitrification efficiency without deterioration of nitrification, while severe membrane fouling occurred. WAS fermentation liquid resulted in an elevated production of proteins and humic acids in bound extracellular polymeric substance (EPS) and release of organic matter with high MW fractions in soluble microbial product (SMP) and loosely bound EPS (LB-EPS). Measurement of deposition rate and fluid structure confirmed increased fouling potential of SMP and LB-EPS. γ-Proteobacteria and Ferruginibacter, which can secrete and export EPS, were also found to be abundant in the MBR with WAS fermentation liquid. It is implied that when WAS fermentation liquid was applied, some operational steps to control membrane fouling should be employed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation and Characterization of Mesoporous Nickel derived from Liquid crystalline Template and Evaluation of its Electro catalytic activity towards Methanol Oxidation

NASA Astrophysics Data System (ADS)

Mohanapriya, S.; Renuka devi, R.; Raj, V.

2018-02-01

Mesoporous Nickel has been prepared by electrodeposition using non-ionic surfactant based liquid crystalline template under optimized processing conditions. Physico-chemical properties of mesoporous nickel is systematically characterized through XRD, SEM and AFM analyses. Comparison of electrocatalytic activity of mesoporous nickel with smooth nickel was interrogated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) analyses. Distinctly enhanced electrocatalytic activity with improved surface poisoning resistance related to mesoporous nickel electrode towards methanol oxidation stems from unique mesoporous morphology. This mesoporous morphology with high surface to volume ratio is highly beneficial to promote active catalytic centers to offer readily accessible Pt catalytic sites for MOR, through facilitating mass and electron transports.

Active background suppression with the liquid argon scintillation veto of GERDA Phase II

NASA Astrophysics Data System (ADS)

Agostini, M.; Allardt, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; Di Marco, N.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Medinaceli, E.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Palioselitis, D.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Salathe, M.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schulz, O.; Schütz, A.-K.; Schwingenheuer, B.; Selivanenko, O.; Shevzik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

2017-09-01

The observation of neutrinoless double beta decay would allow to shed light onto the particle nature of neutrinos. Gerda is aiming to perform a background-free search for this process using high purity germanium detectors enriched in 76Ge operated in liquid argon. This goal relies on the application of active background suppression techniques. A low background light instrumentation has been installed for Phase II to detect events with coincident energy deposition in the nearby liquid argon. The intended background index of ˜10-3 cts/(keV·ky·yr) has been confirmed.

The effects of high concentrations of ionic liquid on GB1 protein structure and dynamics probed by high-resolution magic-angle-spinning NMR spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warner, Lisa; Gjersing, Erica; Follett, Shelby E.

Ionic liquids have great potential in biological applications and biocatalysis, as some ionic liquids can stabilize proteins and enhance enzyme activity, while others have the opposite effect. However, on the molecular level, probing ionic liquid interactions with proteins, especially in solutions containing high concentrations of ionic liquids, has been challenging. In the present work the 13C, 15N-enriched GB1 model protein was used to demonstrate applicability of high-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy to investigate ionic liquid-protein interactions. Effect of an ionic liquid (1-butyl-3-methylimidazolium bromide, [C 4-mim]Br) on GB1was studied over a wide range of the ionic liquid concentrations (0.6-3.5 M, whichmore » corresponds to 10-60% v/v). Interactions between GB1 and [C 4-mim]Br were observed from changes in the chemical shifts of the protein backbone as well as the changes in 15N ps-ns dynamics and rotational correlation times. Site-specific interactions between the protein and [C 4-mim]Br were assigned using 3D methods under HR-MAS conditions. Furthermore, HR-MAS NMR is a viable tool that could aid in elucidation of molecular mechanisms of ionic liquid-protein interactions.« less

The effects of high concentrations of ionic liquid on GB1 protein structure and dynamics probed by high-resolution magic-angle-spinning NMR spectroscopy

DOE PAGES

Warner, Lisa; Gjersing, Erica; Follett, Shelby E.; ...

2016-08-11

Ionic liquids have great potential in biological applications and biocatalysis, as some ionic liquids can stabilize proteins and enhance enzyme activity, while others have the opposite effect. However, on the molecular level, probing ionic liquid interactions with proteins, especially in solutions containing high concentrations of ionic liquids, has been challenging. In the present work the 13C, 15N-enriched GB1 model protein was used to demonstrate applicability of high-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy to investigate ionic liquid-protein interactions. Effect of an ionic liquid (1-butyl-3-methylimidazolium bromide, [C 4-mim]Br) on GB1was studied over a wide range of the ionic liquid concentrations (0.6-3.5 M, whichmore » corresponds to 10-60% v/v). Interactions between GB1 and [C 4-mim]Br were observed from changes in the chemical shifts of the protein backbone as well as the changes in 15N ps-ns dynamics and rotational correlation times. Site-specific interactions between the protein and [C 4-mim]Br were assigned using 3D methods under HR-MAS conditions. Furthermore, HR-MAS NMR is a viable tool that could aid in elucidation of molecular mechanisms of ionic liquid-protein interactions.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, L. H.; Wang, X. D.; Yu, Q.

Temperature-dependent atomistic structure evolution of liquid gallium (Ga) has been investigated by using in situ high energy X-ray diffraction experiment and ab initio molecular dynamics simulation. Both experimental and theoretical results reveal the existence of a liquid structural change around 1000 K in liquid Ga. Below and above this temperature the liquid exhibits differences in activation energy for selfdiffusion, temperature-dependent heat capacity, coordination numbers, density, viscosity, electric resistivity and thermoelectric power, which are reflected from structural changes of the bond-orientational order parameter Q6, fraction of covalent dimers, averaged string length and local atomic packing. This finding will trigger more studiesmore » on the liquid-to-liquid crossover in metallic melts.« less

Ionic liquid-mediated synthesis of meso-scale porous lanthanum-transition-metal perovskites with high CO oxidation performance

DOE PAGES

Lu, Hanfeng; Zhang, Pengfei; Qiao, Zhen-An; ...

2015-02-19

Lanthanum-transition-metal perovskites with robust meso-scale porous frameworks (meso-LaMO 3) are synthesized through use of ionic liquids. The resultant samples demonstrate a rather high activity for CO oxidation, by taking advantage of unique nanostructure-derived benefits. This synthesis strategy opens up a new opportunity for preparing functional mesoporous complex oxides of various compositions.

Ionic liquid-mediated synthesis of meso-scale porous lanthanum-transition-metal perovskites with high CO oxidation performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Hanfeng; Zhang, Pengfei; Qiao, Zhen-An

Lanthanum-transition-metal perovskites with robust meso-scale porous frameworks (meso-LaMO 3) are synthesized through use of ionic liquids. The resultant samples demonstrate a rather high activity for CO oxidation, by taking advantage of unique nanostructure-derived benefits. This synthesis strategy opens up a new opportunity for preparing functional mesoporous complex oxides of various compositions.

Comparison of exogenous surfactant therapy, mechanical ventilation with high end-expiratory pressure and partial liquid ventilation in a model of acute lung injury.

PubMed

Hartog, A; Vazquez de Anda, G F; Gommers, D; Kaisers, U; Verbrugge, S J; Schnabel, R; Lachmann, B

1999-01-01

We have compared three treatment strategies, that aim to prevent repetitive alveolar collapse, for their effect on gas exchange, lung mechanics, lung injury, protein transfer into the alveoli and surfactant system, in a model of acute lung injury. In adult rats, the lungs were ventilated mechanically with 100% oxygen and a PEEP of 6 cm H2O, and acute lung injury was induced by repeated lung lavage to obtain a PaO2 value < 13 kPa. Animals were then allocated randomly (n = 12 in each group) to receive exogenous surfactant therapy, ventilation with high PEEP (18 cm H2O), partial liquid ventilation or ventilation with low PEEP (8 cm H2O) (ventilated controls). Blood-gas values were measured hourly. At the end of the 4-h study, in six animals per group, pressure-volume curves were constructed and bronchoalveolar lavage (BAL) was performed, whereas in the remaining animals lung injury was assessed. In the ventilated control group, arterial oxygenation did not improve and protein concentration of BAL and conversion of active to non-active surfactant components increased significantly. In the three treatment groups, PaO2 increased rapidly to > 50 kPa and remained stable over the next 4 h. The protein concentration of BAL fluid increased significantly only in the partial liquid ventilation group. Conversion of active to non-active surfactant components increased significantly in the partial liquid ventilation group and in the group ventilated with high PEEP. In the surfactant group and partial liquid ventilation groups, less lung injury was found compared with the ventilated control group and the group ventilated with high PEEP. We conclude that although all three strategies improved PaO2 to > 50 kPa, the impact on protein transfer into the alveoli, surfactant system and lung injury differed markedly.

Application of response surface methodology to optimize pressurized liquid extraction of antioxidant compounds from sage (Salvia officinalis L.), basil (Ocimum basilicum L.) and thyme (Thymus vulgaris L.).

PubMed

Hossain, M B; Brunton, N P; Martin-Diana, A B; Barry-Ryan, C

2010-12-01

The present study optimized pressurized liquid extraction (PLE) conditions using Dionex ASE® 200, USA to maximize the antioxidant activity [Ferric ion Reducing Antioxidant Power (FRAP)] and total polyphenol content (TP) of the extracts from three spices of Lamiaceae family (sage, basil and thyme). Optimal conditions with regard to extraction temperature (66-129 °C) and solvent concentration (32-88% methanol) were identified using response surface methodology (RSM). For all three spices, results showed that 129 °C was the optimum temperature with regard to antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of sage and basil extracts were 58% and 60% respectively. Thyme showed a different trend with regard to methanol concentration and was optimally extracted at 33%. Antioxidant activity yields of the optimal PLE were significantly (p < 0.05) higher than solid/liquid extracts. Predicted models were highly significant (p < 0.05) for both total phenol (TP) and FRAP values in all the spices with high regression coefficients (R(2)) ranging from 0.651 to 0.999.

High-sensitivity liquid refractive-index sensor based on a Mach-Zehnder interferometer with a double-slot hybrid plasmonic waveguide.

PubMed

Sun, Xu; Dai, Daoxin; Thylén, Lars; Wosinski, Lech

2015-10-05

A Mach-Zehnder Interferometer (MZI) liquid sensor, employing ultra-compact double-slot hybrid plasmonic (DSHP) waveguide as active sensing arm, is developed. Numerical results show that extremely large optical confinement factor of the tested analytes (as high as 88%) can be obtained by DSHP waveguide with optimized geometrical parameters, which is larger than both, conventional SOI waveguides and plasmonic slot waveguides with same widths. As for MZI sensor with 40μm long DSHP active sensing area, the sensitivity can reach as high value as 1061nm/RIU (refractive index unit). The total loss, excluding the coupling loss of the grating coupler, is around 4.5dB.

Screening, separation, and evaluation of xanthine oxidase inhibitors from Paeonia lactiflora using chromatography combined with a multi-mode microplate reader.

PubMed

Wang, Jing; Shi, Dongfang; Zheng, Meizhu; Ma, Bing; Cui, Jing; Liu, Chunming; Liu, Chengyu

2017-11-01

Natural products have become one of the most important resources for discovering novel xanthine oxidase inhibitors, which are commonly employed in the treatment of hyperuricemia and gout. However, to date, few reports exist regarding the use of monoterpene glycosides as xanthine oxidase inhibitors. Thus, we herein report the use of ultrafiltration coupled with liquid chromatography in the screening of monoterpene glycoside xanthine oxidase inhibitors from the extract of Paeonia lactiflora (P. lactiflora), and both high-performance counter-current chromatography and medium-pressure liquid chromatography were employed to separate the main constituents. Furthermore, the xanthine oxidase inhibitory activities and the mechanisms of inhibition of the isolated compounds were evaluated using a multi-mode microplate reader by Molecular Devices. As a result, three monoterpene glycosides were separated by combined high-performance counter-current chromatography and medium-pressure liquid chromatography in purities of 90.4, 98.0, and 86.3%, as determined by liquid chromatography. These three compounds were identified as albiflorin, paeoniflorin, and 1-O-β-ᴅ-glucopyranosyl-8-O-benzoylpaeonisuffrone by electrospray ionization tandem mass spectrometry, and albiflorin and paeoniflorin were screened as potential xanthine oxidase inhibitors by ultrafiltration with liquid chromatography. The evaluation results of xanthine oxidase inhibitory activity corresponded with the screening results, as only albiflorin and paeoniflorin exhibited xanthine oxidase inhibitory activity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surface and Electrochemical Properties of Polymer Brush-Based Redox Poly(Ionic Liquid).

PubMed

Bui-Thi-Tuyet, Van; Trippé-Allard, Gaëlle; Ghilane, Jalal; Randriamahazaka, Hyacinthe

2016-10-26

Redox-active poly(ionic liquid) poly(3-(2-methacryloyloxy ethyl)-1-(N-(ferrocenylmethyl) imidazolium bis(trifluoromethylsulfonyl)imide deposited onto electrode surfaces has been prepared using surface-initiated atom transfer radical polymerization SI-ATRP. The process starts by electrochemical immobilization of initiator layer, and then methacrylate monomer carrying ferrocene and imidazolium units is polymerized in ionic liquid media via SI-ATRP process. The surfaces analyses of the polymer exhibit a well-defined polymer brushlike structure and confirm the presence of ferrocene and ionic moieties within the film. Furthermore, the electrochemical investigations of poly(redox-active ionic liquid) in different media demonstrate that the electron transfer is not restricted by the rate of counterion migration into/out of the polymer. The attractive electrochemical performance of these materials is further demonstrated by performing electrochemical measurement, of poly(ferrocene ionic liquid), in solvent-free electrolyte. The facile synthesis of such highly ordered electroactive materials based ionic liquid could be useful for the fabrication of nanostructured electrode suitable for performing electrochemistry in solvent free electrolyte. We also demonstrate possible applications of the poly(FcIL) as electrochemically reversible surface wettability system and as electrochemical sensor for the catalytic activity toward the oxidation of tyrosine.

Long-range electrostatic screening in ionic liquids

PubMed Central

Gebbie, Matthew A.; Dobbs, Howard A.; Valtiner, Markus; Israelachvili, Jacob N.

2015-01-01

Electrolyte solutions with high concentrations of ions are prevalent in biological systems and energy storage technologies. Nevertheless, the high interaction free energy and long-range nature of electrostatic interactions makes the development of a general conceptual picture of concentrated electrolytes a significant challenge. In this work, we study ionic liquids, single-component liquids composed solely of ions, in an attempt to provide a novel perspective on electrostatic screening in very high concentration (nonideal) electrolytes. We use temperature-dependent surface force measurements to demonstrate that the long-range, exponentially decaying diffuse double-layer forces observed across ionic liquids exhibit a pronounced temperature dependence: Increasing the temperature decreases the measured exponential (Debye) decay length, implying an increase in the thermally driven effective free-ion concentration in the bulk ionic liquids. We use our quantitative results to propose a general model of long-range electrostatic screening in ionic liquids, where thermally activated charge fluctuations, either free ions or correlated domains (quasiparticles), take on the role of ions in traditional dilute electrolyte solutions. This picture represents a crucial step toward resolving several inconsistencies surrounding electrostatic screening and charge transport in ionic liquids that have impeded progress within the interdisciplinary ionic liquids community. More broadly, our work provides a previously unidentified way of envisioning highly concentrated electrolytes, with implications for diverse areas of inquiry, ranging from designing electrochemical devices to rationalizing electrostatic interactions in biological systems. PMID:26040001

Kelvin Probe Force Microscopy in liquid using Electrochemical Force Microscopy

DOE PAGES

Collins, Liam; Jesse, Stephen; Kilpatrick, J.; ...

2015-01-19

Conventional closed loop-Kelvin probe force microscopy (KPFM) has emerged as a powerful technique for probing electric and transport phenomena at the solid-gas interface. The extension of KPFM capabilities to probe electrostatic and electrochemical phenomena at the solid–liquid interface is of interest for a broad range of applications from energy storage to biological systems. However, the operation of KPFM implicitly relies on the presence of a linear lossless dielectric in the probe-sample gap, a condition which is violated for ionically-active liquids (e.g., when diffuse charge dynamics are present). Here, electrostatic and electrochemical measurements are demonstrated in ionically-active (polar isopropanol, milli-Q watermore » and aqueous NaCl) and ionically-inactive (non-polar decane) liquids by electrochemical force microscopy (EcFM), a multidimensional (i.e., bias- and time-resolved) spectroscopy method. In the absence of mobile charges (ambient and non-polar liquids), KPFM and EcFM are both feasible, yielding comparable contact potential difference (CPD) values. In ionically-active liquids, KPFM is not possible and EcFM can be used to measure the dynamic CPD and a rich spectrum of information pertaining to charge screening, ion diffusion, and electrochemical processes (e.g., Faradaic reactions). EcFM measurements conducted in isopropanol and milli-Q water over Au and highly ordered pyrolytic graphite electrodes demonstrate both sample- and solvent-dependent features. Finally, the feasibility of using EcFM as a local force-based mapping technique of material-dependent electrostatic and electrochemical response is investigated. The resultant high dimensional dataset is visualized using a purely statistical approach that does not require a priori physical models, allowing for qualitative mapping of electrostatic and electrochemical material properties at the solid–liquid interface.« less

Highly sensitive assay for tyrosine hydroxylase activity by high-performance liquid chromatography.

PubMed

Nagatsu, T; Oka, K; Kato, T

1979-07-21

A highly sensitive assay for tyrosine hydroxylase (TH) activity by high-performance liquid chromatography (HPLC) with amperometric detection was devised based on the rapid isolation of enzymatically formed DOPA by a double-column procedure, the columns fitted together sequentially (the top column of Amberlite CG-50 and the bottom column of aluminium oxide). DOPA was adsorbed on the second aluminium oxide column, then eluted with 0.5 M hydrochloric acid, and assayed by HPLC with amperometric detection. D-Tyrosine was used for the control. alpha-Methyldopa was added to the incubation mixture as an internal standard after incubation. This assay was more sensitive than radioassays and 5 pmol of DOPA formed enzymatically could be measured in the presence of saturating concentrations of tyrosine and 6-methyltetrahydropterin. The TH activity in 2 mg of human putamen could be easily measured, and this method was found to be particularly suitable for the assay of TH activity in a small number of nuclei from animal and human brain.

Selective hydrogenation of phenol to cyclohexanone over Pd@CN (N-doped porous carbon): Role of catalyst reduction method

NASA Astrophysics Data System (ADS)

Hu, Shuo; Yang, Guangxin; Jiang, Hong; Liu, Yefei; Chen, Rizhi

2018-03-01

Selective phenol hydrogenation is a green and sustainable technology to produce cyclohexanone. The work focused on investigating the role of catalyst reduction method in the liquid-phase phenol hydrogenation to cyclohexanone over Pd@CN (N-doped porous carbon). A series of reduction methods including flowing hydrogen reduction, in-situ reaction reduction and liquid-phase reduction were designed and performed. The results highlighted that the reduction method significantly affected the catalytic performance of Pd@CN in the liquid-phase hydrogenation of phenol to cyclohexanone, and the liquid-phase reduction with the addition of appropriate amount of phenol was highly efficient to improve the catalytic activity of Pd@CN. The influence mechanism was explored by a series of characterizations. The results of TEM, XPS and CO chemisorption confirmed that the reduction method mainly affected the size, surface composition and dispersion of Pd in the CN material. The addition of phenol during the liquid-phase reduction could inhibit the aggregation of Pd NPs and promote the reduction of Pd (2+), and then improved the catalytic activity of Pd@CN. The work would aid the development of high-performance Pd@CN catalysts for selective phenol hydrogenation.

Millimeter-scale liquid metal droplet thermal switch

NASA Astrophysics Data System (ADS)

Yang, Tianyu; Kwon, Beomjin; Weisensee, Patricia B.; Kang, Jin Gu; Li, Xuejiao; Braun, Paul; Miljkovic, Nenad; King, William P.

2018-02-01

Devices capable of actively controlling heat flow have been desired by the thermal management community for decades. The need for thermal control has become particularly urgent with power densification resulting in devices with localized heat fluxes as high as 1 kW/cm2. Thermal switches, capable of modulating between high and low thermal conductances, enable the partitioning and active control of heat flow pathways. This paper reports a millimeter-scale thermal switch with a switching ratio >70, at heat fluxes near 10 W/cm2. The device consists of a silicone channel filled with a reducing liquid or vapor and an immersed liquid metal Galinstan slug. Galinstan has a relatively high thermal conductivity (≈16.5 W/mK at room temperature), and its position can be manipulated within the fluid channel, using either hydrostatic pressure or electric fields. When Galinstan bridges the hot and cold reservoirs (the "ON" state), heat flows across the channel. When the hot and cold reservoirs are instead filled with the encapsulating liquid or vapor (the "OFF" state), the cross-channel heat flow significantly reduces due to the lower thermal conductivity of the solution (≈0.03-0.6 W/mK). We demonstrate switching ratios as high as 15.6 for liquid filled channels and 71.3 for vapor filled channels. This work provides a framework for the development of millimeter-scale thermal switches and diodes capable of spatial and temporal control of heat flows.

Synthesis and anti-microbial activity of hydroxylammonium ionic liquids.

PubMed

Ismail Hossain, M; El-Harbawi, Mohanad; Noaman, Yousr Abdulhadi; Bustam, Mohd Azmi B; Alitheen, Noorjahan Banu Mohamed; Affandi, Nor Azrin; Hefter, Glenn; Yin, Chun-Yang

2011-06-01

Eight hydroxylammonium-based room temperature ionic liquids (ILs) have been synthesized by acid-base neutralization of ethanolamines with organic acids. The ILs were characterized by infrared and nuclear magnetic resonance spectroscopies and elemental analysis. Their anti-microbial activities were determined using the well-diffusion method. All eight ILs were toxic to Staphylococcus aureus, while 2-hydroxyethylammonium lactate and 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium acetate showed high anti-microbial activity against a wide range of human pathogens. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Development of On-Line High Performance Liquid Chromatography (HPLC)-Biochemical Detection Methods as Tools in the Identification of Bioactives

PubMed Central

Malherbe, Christiaan J.; de Beer, Dalene; Joubert, Elizabeth

2012-01-01

Biochemical detection (BCD) methods are commonly used to screen plant extracts for specific biological activities in batch assays. Traditionally, bioactives in the most active extracts were identified through time-consuming bio-assay guided fractionation until single active compounds could be isolated. Not only are isolation procedures often tedious, but they could also lead to artifact formation. On-line coupling of BCD assays to high performance liquid chromatography (HPLC) is gaining ground as a high resolution screening technique to overcome problems associated with pre-isolation by measuring the effects of compounds post-column directly after separation. To date, several on-line HPLC-BCD assays, applied to whole plant extracts and mixtures, have been published. In this review the focus will fall on enzyme-based, receptor-based and antioxidant assays. PMID:22489144

XPS analysis of activated carbon supported ionic liquids: Enhanced purity and reduced charging

NASA Astrophysics Data System (ADS)

Foelske-Schmitz, A.; Weingarth, D.; Kötz, R.

2011-12-01

Herein we report on XPS measurements on five different [EMIM] based ionic liquids (IL) prepared on activated carbon and aluminium supports. The anions were [TFSI], [BF4], [FAP], [B(CN)4] and [EtOSO3]. The results show that impurities such as O, Si or hydrocarbons were significantly reduced or no longer detected when preparation was performed on the high surface area carbon support. All core level spectra were fitted and for [EMIM][FAP], [EMIM][B(CN)4] and [EMIM][EtOSO3] de-convolution procedures of the C 1s lines are suggested. Comparison of the determined binding energies with published data strongly suggests that sample charging is irrelevant when preparation is performed on the activated carbon support. This observation is supposed to refer to the high capacitance of the high surface area carbon.

Onset of space charge effects in liquid argon ionization chambers

NASA Astrophysics Data System (ADS)

Toggerson, B.; Newcomer, A.; Rutherfoord, J.; Walker, R. B.

2009-09-01

Using a thin-gap liquid argon ionization chamber and Strontium-90 beta sources we have measured ionization currents over a wide range of gap potentials. These precision "HV plateau curves" advance the understanding of liquid argon sampling calorimeter signals, particularly at high ionization rates. The order of magnitude differences in the activities of the beta sources allow us to estimate where the ionization chamber is driven into the space-charge dominated regime.

Delivery of Formulated Industrial Enzymes with Acoustic Technology.

PubMed

Hwang, Jennifer Dorcas; Ortiz-Maldonado, Mariliz; Paramonov, Sergey

2016-02-01

Industrial enzymes are instrumental in many applications, including carbohydrate processing, fabric and household care, biofuels, food, and animal nutrition, among others. Enzymes have to be active and stable not only in harsh application conditions, but also during shipment and storage. In protein stability studies, formulated concentrated enzyme solutions are frequently diluted gravimetrically prior to enzyme activity measurements, making it challenging to move toward more high-throughput techniques using conventional robotic equipment. Current assay methods pose difficulties when measuring highly concentrated proteins. For example, plastic pipette tips can introduce error because proteins adsorb to the tip surface, despite the presence of detergents, decreasing precision and overall efficiency of protein activity assays. Acoustic liquid handling technology, frequently used for various dilute small-molecule assays, may overcome such problems. Originally shown to effectively deliver dilute solutions of small molecules, this technology is used here as an effective alternative to the aforementioned challenge with viscous concentrated protein solutions. Because the acoustic liquid handler transfers nanoliter quantities of liquids without using pipette tips and without sample loss, it rapidly and uniformly prepares assay plates for enzyme activity measurements within minutes. This increased efficiency transforms the nature of enzyme stability studies toward high precision and throughput. © 2015 Society for Laboratory Automation and Screening.

Liquid-permeable electrode

DOEpatents

Folser, George R.

1980-01-01

Electrodes for use in an electrolytic cell, which are liquid-permeable and have low electrical resistance and high internal surface area are provided of a rigid, porous, carbonaceous matrix having activated carbon uniformly embedded throughout. The activated carbon may be catalyzed with platinum for improved electron transfer between electrode and electrolyte. Activated carbon is mixed with a powdered thermosetting phenolic resin and compacted to the desired shape in a heated mold to melt the resin and form the green electrode. The compact is then heated to a pyrolyzing temperature to carbonize and volatilize the resin, forming a rigid, porous structure. The permeable structure and high internal surface area are useful in electrolytic cells where it is necessary to continuously remove the products of the electrochemical reaction.

Novel applications of ionic liquids in materials processing

NASA Astrophysics Data System (ADS)

Reddy, Ramana G.

2009-05-01

Ionic liquids are mixtures of organic and inorganic salts which are liquids at room temperature. Several potential applications of ionic liquids in the field of materials processing are electrowinning and electrodeposition of metals and alloys, electrolysis of active metals at low temperature, liquid-liquid extraction of metals. Results using 1-butyl-3-methylimidazolium chloride with AlCl3 at low temperatures yielded high purity aluminium deposits (>99.9% pure) and current efficiencies >98%. Titanium and aluminium were co-deposited with/without the addition of TiCl4 with up to 27 wt% Ti in the deposit with current efficiencies in the range of 78-85 %. Certain ionic liquids are potential replacements for thermal oils and molten salts as heat transfer fluids in solar energy applications due to high thermal stability, very low corrosivity and substantial sensible heat retentivity. The calculated storage densities for several chloride and fluoride ionic liquids are in the range of 160-210 MJ/m3. A 3-D mathematical model was developed to simulate the large scale electrowinning of aluminium. Since ionic liquids processing results in their low energy consumption, low pollutant emissions many more materials processing applications are expected in future.

Ionic liquid-assisted synthesis of highly dispersive bowknot-like ZnO microrods for photocatalytic applications

NASA Astrophysics Data System (ADS)

Zhao, Shuo; Zhang, Yiwei; Zhou, Yuming; Zhang, Chao; Sheng, Xiaoli; Fang, Jiasheng; Zhang, Mingyu; Yang, Yong

2017-04-01

Here we present a facile method for the preparation of highly dispersive ZnO materials by using ionic liquid 1-methyl-3-[3‧-(trimethoxysilyl) propyl] imidazolium chloride as the template. The influence of ionic liquid concentration and calcined atmosphere on the photoactivity is studied. The samples were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), scanning electron microscope (SEM), N2 gas sorption and ultraviolet-visible diffuse reflectance spectroscopy. The results showed that the as-fabricated ZnO materials consisted of individual microrods with self-assembled bowknot-like architecture whose size was about 1 μm. The formation mechanism of the bowknot-like ZnO materials which is based on the self-assembly of ionic liquid is tentatively elucidated. Moreover, the ZnO-2.6N sample exhibited the higher activity for the photodegradation of MB than the photodegradation of MO and RhB. Furthermore, it was found that the ZnO materials calcined under air atmosphere showed the better photocatalytic activities than that of samples calcined under nitrogen atmosphere in the degradation of methylene blue (MB) under UV irradiation. And the special structure, surface area, adsorption capability of dye, the separation rate of photogenerated electron-hole pairs and band gap had effects on the photocatalytic activity of ZnO photocatalysts. O2rad - was the main active species for the photocatalytic degradation of MB. It is valuable to develop this facile route preparing the highly dispersive bowknot-like ZnO materials and the ZnO materials can be beneficial for environmental protection.

Active suppression of vortex-driven combustion instability using controlled liquid-fuel injection

NASA Astrophysics Data System (ADS)

Pang, Bin

Combustion instabilities remain one of the most challenging problems encountered in developing propulsion and power systems. Large amplitude pressure oscillations, driven by unsteady heat release, can produce numerous detrimental effects. Most previous active control studies utilized gaseous fuels to suppress combustion instabilities. However, using liquid fuel to suppress combustion instabilities is more realistic for propulsion applications. Active instability suppression in vortex-driven combustors using a direct liquid fuel injection strategy was theoretically established and experimentally demonstrated in this dissertation work. Droplet size measurements revealed that with pulsed fuel injection management, fuel droplet size could be modulated periodically. Consequently, desired heat release fluctuation could be created. If this oscillatory heat release is coupled with the natural pressure oscillation in an out of phase manner, combustion instabilities can be suppressed. To identify proper locations of supplying additional liquid fuel for the purpose of achieving control, the natural heat release pattern in a vortex-driven combustor was characterized in this study. It was found that at high Damkohler number oscillatory heat release pattern closely followed the evolving vortex front. However, when Damkohler number became close to unity, heat release fluctuation wave no longer coincided with the coherent structures. A heat release deficit area was found near the dump plane when combustor was operated in lean premixed conditions. Active combustion instability suppression experiments were performed in a dump combustor using a controlled liquid fuel injection strategy. High-speed Schlieren results illustrated that vortex shedding plays an important role in maintaining self-sustained combustion instabilities. Complete combustion instability control requires total suppression of these large-scale coherent structures. The sound pressure level at the excited dominant frequency was reduced by more than 20 dB with controlled liquid fuel injection method. Scaling issues were also investigated in this dump combustor to test the effectiveness of using pulsed liquid fuel injection strategies to suppress instabilities at higher power output conditions. With the liquid fuel injection control method, it was possible to suppress strong instabilities with initial amplitude of +/-5 psi down to the background noise level. The stable combustor operating range was also expanded from equivalence ratio of 0.75 to beyond 0.9.

A novel approach to prepare optically active ion doped luminescent materials via electron beam evaporation into ionic liquids

DOE PAGES

Richter, K.; Lorbeer, C.; Mudring, A. -V.

2014-11-10

A novel approach to prepare luminescent materials via electron-beam evaporation into ionic liquids is presented which even allows doping of host lattices with ions that have a strong size mismatch. Thus, to prove this, MgF 2 nanoparticles doped with Eu 3+ were fabricated. The obtained nanoparticles featured an unusually high luminescence lifetime and the obtained material showed a high potential for application.

Micro-polarimeter for high performance liquid chromatography

DOEpatents

Yeung, Edward E.; Steenhoek, Larry E.; Woodruff, Steven D.; Kuo, Jeng-Chung

1985-01-01

A micro-polarimeter interfaced with a system for high performance liquid chromatography, for quantitatively analyzing micro and trace amounts of optically active organic molecules, particularly carbohydrates. A flow cell with a narrow bore is connected to a high performance liquid chromatography system. Thin, low birefringence cell windows cover opposite ends of the bore. A focused and polarized laser beam is directed along the longitudinal axis of the bore as an eluent containing the organic molecules is pumped through the cell. The beam is modulated by air gap Faraday rotators for phase sensitive detection to enhance the signal to noise ratio. An analyzer records the beams's direction of polarization after it passes through the cell. Calibration of the liquid chromatography system allows determination of the quantity of organic molecules present from a determination of the degree to which the polarized beam is rotated when it passes through the eluent.

GC/MS analysis of high-performance liquid chromatography fractions from Sophora flavescens and Torilis japonica extracts and their in vitro anti-neosporal effects on Neospora caninum.

PubMed

Seo, Hun-Su; Kim, Kyoung Hee; Kim, Dae-Yong; Park, Bong-Kyun; Shin, Nam-Shik; Kim, Jae-Hoon; Youn, Heejeong

2013-01-01

We analyzed alcoholic extracts of herbs possessing anti-neosporal activity against Neospora (N.) caninum. To identify the chemical components of Sophora (S.) flavescens and Torilis (T.) japonica associated with anti-neosporal activity, specific fractions were isolated by high-performance liquid chromatography (HPLC). In vitro activity of the fractions against N. caninum was then assessed. Gas chromatography/ mass spectrometry (GC/MS) was used to identify and quantify specific anti-neosporal molecules in the herbal extracts. Almost all HPLC fractions of S. flavescens and T. japonica had higher levels of anti-neosporal activity compared to the not treated control. Active constituents of the extracts were sophoridane, furosardonin A, and tetraisopropylidene-cyclobutane in S. flavescens; 5,17-β-dihydroxy-de-A-estra-5,7,9,14-tetraene, furanodiene, and 9,12-octadecadienoic acid (Z,Z)-(CAS,1) in T. japonica.

GC/MS analysis of high-performance liquid chromatography fractions from Sophora flavescens and Torilis japonica extracts and their in vitro anti-neosporal effects on Neospora caninum

PubMed Central

Seo, Hun-Su; Kim, Kyoung Hee; Kim, Dae-Yong; Park, Bong-Kyun; Shin, Nam-Shik; Kim, Jae-Hoon

2013-01-01

We analyzed alcoholic extracts of herbs possessing anti-neosporal activity against Neospora (N.) caninum. To identify the chemical components of Sophora (S.) flavescens and Torilis (T.) japonica associated with anti-neosporal activity, specific fractions were isolated by high-performance liquid chromatography (HPLC). In vitro activity of the fractions against N. caninum was then assessed. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify specific anti-neosporal molecules in the herbal extracts. Almost all HPLC fractions of S. flavescens and T. japonica had higher levels of anti-neosporal activity compared to the not treated control. Active constituents of the extracts were sophoridane, furosardonin A, and tetraisopropylidene-cyclobutane in S. flavescens; 5,17-β-dihydroxy-de-A-estra-5,7,9,14-tetraene, furanodiene, and 9,12-octadecadienoic acid (Z,Z)-(CAS,1) in T. japonica. PMID:23820198

Downstream valorization and comprehensive two-dimensional liquid chromatography-based chemical characterization of bioactives from black chokeberries (Aronia melanocarpa) pomace.

PubMed

Brazdauskas, T; Montero, L; Venskutonis, P R; Ibañez, E; Herrero, M

2016-10-14

In this work, a new alternative for the downstream processing and valorization of black chokeberry pomace (Aronia melanocarpa) which could be potentially coupled to a biorefinery process is proposed. This alternative is based on the application of pressurized liquid extraction (PLE) to the residue obtained after the supercritical fluid extraction of the berry pomace. An experimental design is employed to study and optimize the most relevant extraction conditions in order to attain extracts with high extraction yields, total phenols content and antioxidant activity. Moreover, the PLE extracts were characterized by using a new method based on the application of comprehensive two-dimensional liquid chromatography in order to correlate their activity with their chemical composition. Thanks to the use of this powerful analytical tool, 61 compounds could be separated being possible the tentative identification of different anthocyanins, proanthocyanidins, flavonoids and phenolic acids. By using the optimized PLE approach (using pressurized 46% ethanol in water at 165°C containing 1.8% formic acid), extracts with high total phenols content (236.6mg GAE g -1 extract) and high antioxidant activities (4.35mmol TE g -1 extract and EC 50 5.92μgmL -1 ) could be obtained with high yields (72.5%). Copyright © 2016 Elsevier B.V. All rights reserved.

46 CFR 39.2007 - Tankship liquid overfill protection-T/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... tankship must be equipped with an intrinsically safe high-level alarm and a tank overfill alarm. (b) If... letters at least 50.8 millimeters (2 inches) high on a white background; and (3) Activate a visible and... millimeters (2 inches) high on a white background; (3) Activate a visible and audible alarm so that it can be...

46 CFR 39.2007 - Tankship liquid overfill protection-T/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... tankship must be equipped with an intrinsically safe high-level alarm and a tank overfill alarm. (b) If... letters at least 50.8 millimeters (2 inches) high on a white background; and (3) Activate a visible and... millimeters (2 inches) high on a white background; (3) Activate a visible and audible alarm so that it can be...

Measurement of the absolute reflectance of polytetrafluoroethylene (PTFE) immersed in liquid xenon

NASA Astrophysics Data System (ADS)

Neves, F.; Lindote, A.; Morozov, A.; Solovov, V.; Silva, C.; Bras, P.; Rodrigues, J. P.; Lopes, M. I.

2017-01-01

The performance of a detector using liquid xenon (LXe) as a scintillator is strongly dependent on the collection efficiency for xenon scintillation light, which in turn is critically dependent on the reflectance of the surfaces that surround the active volume. To improve the light collection in such detectors the active volume is usually surrounded by polytetrafluoroethylene (PTFE) reflector panels, used due to its very high reflectance—even at the short wavelength of scintillation light of LXe (peaked at 178 nm). In this work, which contributed to the overall R&D effort towards the LUX-ZEPLIN (LZ) experiment, we present experimental results for the absolute reflectance measurements of three different PTFE samples (including the material used in the LUX detector) immersed in LXe for its scintillation light. The obtained results show that very high bi-hemispherical reflectance values (>= 97%) can be achieved, enabling very low energy thresholds in liquid xenon scintillator-based detectors.

Liquid metals for solar power systems

NASA Astrophysics Data System (ADS)

Flesch, J.; Niedermeier, K.; Fritsch, A.; Musaeva, D.; Marocco, L.; Uhlig, R.; Baake, E.; Buck, R.; Wetzel, T.

2017-07-01

The use of liquid metals in solar power systems is not new. The receiver tests with liquid sodium in the 1980s at the Plataforma Solar de Almería (PSA) already proved the feasibility of liquid metals as heat transfer fluid. Despite the high efficiency achieved with that receiver, further investigation of liquid metals in solar power systems was stopped due to a sodium spray fire. Recently, the topic has become interesting again and the gained experience during the last 30 years of liquid metals handling is applied to the concentrated solar power community. In this paper, recent activities of the Helmholtz Alliance LIMTECH concerning liquid metals for solar power systems are presented. In addition to the components and system simulations also the experimental setup and results are included.

Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200 C and method of fabrication

DOEpatents

Carey, P.G.; Smith, P.M.; Havens, J.H.; Jones, P.

1999-01-05

Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100 C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired. 12 figs.

Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200.degree. C and method of fabrication

DOEpatents

Carey, Paul G.; Smith, Patrick M.; Havens, John; Jones, Phil

1999-01-01

Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100.degree. C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired.

Microscopic Theory for the Role of Attractive Forces in the Dynamics of Supercooled Liquids.

PubMed

Dell, Zachary E; Schweizer, Kenneth S

2015-11-13

We formulate a microscopic, no adjustable parameter, theory of activated relaxation in supercooled liquids directly in terms of the repulsive and attractive forces within the framework of pair correlations. Under isochoric conditions, attractive forces can nonperturbatively modify slow dynamics, but at high enough density their influence vanishes. Under isobaric conditions, attractive forces play a minor role. High temperature apparent Arrhenius behavior and density-temperature scaling are predicted. Our results are consistent with recent isochoric simulations and isobaric experiments on a deeply supercooled molecular liquid. The approach can be generalized to treat colloidal gelation and glass melting, and other soft matter slow dynamics problems.

Δ9-Tetrahydrocannabinolic acid synthase: The application of a plant secondary metabolite enzyme in biocatalytic chemical synthesis.

PubMed

Lange, Kerstin; Schmid, Andreas; Julsing, Mattijs K

2016-09-10

Δ(9)-Tetrahydrocannabinolic acid synthase (THCAS) from the secondary metabolism of Cannabis sativa L. catalyzes the oxidative formation of an intramolecular CC bond in cannabigerolic acid (CBGA) to synthesize Δ(9)-tetrahydrocannabinolic acid (THCA), which is the direct precursor of Δ(9)-tetrahydrocannabinol (Δ(9)-THC). Aiming on a biotechnological production of cannabinoids, we investigated the potential of the heterologously produced plant oxidase in a cell-free system on preparative scale. THCAS was characterized in an aqueous/organic two-liquid phase setup in order to solubilize the hydrophobic substrate and to allow in situ product removal. Compared to the single phase aqueous setup the specific activity decreased by a factor of approximately 2 pointing to a substrate limitation of CBGA in the two-liquid phase system. However, the specific activity remained stable for at least 3h illustrating the benefit of the two-liquid phase setup. In a repeated-batch setup, THCAS showed only a minor loss of specific activity in the third batch pointing to a high intrinsic stability and high solvent tolerance of the enzyme. Maximal space-time-yields of 0.121gL(-1)h(-1) were reached proving the two-liquid phase concept suitable for biotechnological production of cannabinoids. Copyright © 2016 Elsevier B.V. All rights reserved.

Antibacterial Activity of Imidazolium-Based Ionic Liquids Investigated by QSAR Modeling and Experimental Studies.

PubMed

Hodyna, Diana; Kovalishyn, Vasyl; Rogalsky, Sergiy; Blagodatnyi, Volodymyr; Petko, Kirill; Metelytsia, Larisa

2016-09-01

Predictive QSAR models for the inhibitors of B. subtilis and Ps. aeruginosa among imidazolium-based ionic liquids were developed using literary data. The regression QSAR models were created through Artificial Neural Network and k-nearest neighbor procedures. The classification QSAR models were constructed using WEKA-RF (random forest) method. The predictive ability of the models was tested by fivefold cross-validation; giving q(2) = 0.77-0.92 for regression models and accuracy 83-88% for classification models. Twenty synthesized samples of 1,3-dialkylimidazolium ionic liquids with predictive value of activity level of antimicrobial potential were evaluated. For all asymmetric 1,3-dialkylimidazolium ionic liquids, only compounds containing at least one radical with alkyl chain length of 12 carbon atoms showed high antibacterial activity. However, the activity of symmetric 1,3-dialkylimidazolium salts was found to have opposite relationship with the length of aliphatic radical being maximum for compounds based on 1,3-dioctylimidazolium cation. The obtained experimental results suggested that the application of classification QSAR models is more accurate for the prediction of activity of new imidazolium-based ILs as potential antibacterials. © 2016 John Wiley & Sons A/S.

[Bis(imidazolyl)-BH₂]+[bis-(triazolyl)-BH₂]- Ionic Liquids with High Density and Energy Capacity.

PubMed

Jiao, Nianming; Li, Hao; Zhang, Yanqiang; Liu, Long; Zhang, Suojiang

2018-05-15

[Bis(imidazolyl)-BH₂]+[bis(triazolyl)-BH₂]- and [bis- (imidazolyl)-BH₂]+[tris(triazolyl)-BH]- were first synthesized, whose cations and anions were all functionalized with B-H groups and azoles. As B-H groups contributing to hypergolic activity and azole groups improving the energy outputs, the resulting ionic liquids exhibited ignition delay time as low as 20 ms and energy output as high as 461.1 kJ mol-1. Besides, densities (1.07-1.22 g∙cm-3) and density-specific impulse (ρIsp, ~ 360 s g cm-3) reach to relatively high level. It has a great promising for those ionic liquids as sustainable rocket fuels. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[The bioelectric activity of the brain in dyscirculatory encephalopathy and arterial hypertension developed in the Chernobyl nuclear disaster liquidators].

PubMed

Podsonnaia, I V; Efremushkin, G G; Zhelobetskaia, E D

2012-01-01

The long-term effects of the ionizing radiation on the bioelectric brain activity in the Chernobyl nuclear disaster liquidators with discirculatory encephalopathy and arterial hypertension were studied. We examined 195 male patients, aged from 30 to 65 years, with the clinical presentations of discirculatory encephalopathy, using electroencephalography: 105 patients were liquidators of the Chernobyl nuclear disaster (the main group) and 90 patients had no radiation anamnesis (the comparison group). It has been found that the development of discirculatory encephalopathy in liquidators of the Chernobyl nuclear disaster is mainly associated with the dysfunction of diencephalic and cortical structures. The specificity of the neurofunctional brain abnormalities in liquidators with discirculatory encephalopathy is characterized by the predominance of the low-amplitude and low-frequency alpha-activity or by the lack of alpha-rhythm and by its substitution for the high-frequency beta-rhythm with the presence of theta- and delta-activity and by the more significant flatness of the alpha-rhythm zonation. The presence of the radiation factor in the past history is correlated with the failure of the bioelectric brain activity in the alpha band (r=0.42) that increases risk of abnormal changes by a factor of 10 (p<0.001). The liquidators with arterial hypertension are characterized by the more frequent occurrence of the asymmetry of the recorded bioelectric potentials between the similar hemispheric areas, by the more significant difference in the external stimulus response of the brain (functional tests). The results indicate the more complicated and diffuse lesion of the brain in the liquidators of the Chernobyl nuclear disaster in the post-radiation period during the development of discirculatory encephalopathy and arterial hypertension.

Effects of dry brining, liquid smoking and high-pressure treatment on the physical properties of aquacultured King salmon (Oncorhynchus tshawytscha) during refrigerated storage.

PubMed

Kong, Kelvin Jia Wey; Alçiçek, Zayde; Balaban, Murat O

2015-03-15

Aquacultured King salmon (Oncorhynchus tshawytscha) pieces were dry brined with a salt/brown sugar mix, dipped in liquid smoke for 3 min, vacuum packed, high hydrostatic pressure (HHP) treated at 600 or 200 MPa for 5 min and stored at 4 °C for up to 40 days. The surface redness (average a*) of the samples increased after dry brining, then decreased after liquid smoke treatment. HHP did not change the outside color of liquid-smoked samples. However, the inside color changed depending on pressure. HHP-treated control samples without dry brining and liquid smoking changed to a pale pink color. HHP at 600 MPa resulted in a significant increase in hardness. Compared with fresh samples, dry-brined samples had reduced water activity, while samples dipped in liquid smoke had lower pH values. Dry brining and liquid smoking protect the outside color of salmon against changes caused by HHP. The increase in hardness may counteract the softening of the smoked salmon tissue over time. © 2014 Society of Chemical Industry.

Hydrogenation of 4-nitrophenol to 4-aminophenol at room temperature: Boosting palladium nanocrystals efficiency by coupling with copper via liquid phase pulsed laser ablation

NASA Astrophysics Data System (ADS)

Park, Hanbit; Reddy, D. Amaranatha; Kim, Yujin; Lee, Seunghee; Ma, Rory; Lim, Manho; Kim, Tae Kyu

2017-04-01

Ultra-dispersed bimetallic nanomaterials have attracted much attention in the hydrogenation of highly toxic aromatic nitro compounds to aromatic amines owing to their high stability, superior activity, reusability, and unique optical and electronic properties, as compared to monometalic nanocrystals. However, the lack of facile and economically controllable strategies of producing highly pure ultra-dispersed bimetallic nanocatalysts limits their practical industrial applications. Considering the above obstacles, we present a simple and effective strategy for the formation of bimetallic (PdCu) nanocrystals by liquid phase pulsed laser ablation using a bulk Pd metal plate submerged in CuCl2 solutions with different concentrations, in contrast to the complex and costly experimental methods used previously. The microstructural and optical properties of the synthesized nanocrystals indicate that the obtained bimetallic nanostructures are highly pure and monodispersed. Moreover, bimetallic PdCu nanostructures show a higher catalytic activity than monometallic Pd nanocrystals for the hydrogenation of 4-nitrophenol to 4-aminophenol at room temperature, also exhibiting high stability for up to four recycles. The mechanism of the enhanced catalytic activity and stability of bimetallic nanocrystals is discussed in detail. Finally, we believe that the presented design strategy and utilization of bimetallic nanocrystals for catalytic applications enables the development of novel bimetallic nanostructures by liquid phase pulsed laser ablation and their catalytic application for environmental remediation.

Comprehensive analysis of pharmaceutical products using simultaneous mixed-mode (ion-exchange/reversed-phase) and hydrophilic interaction liquid chromatography.

PubMed

Kazarian, Artaches A; Nesterenko, Pavel N; Soisungnoen, Phimpha; Burakham, Rodjana; Srijaranai, Supalax; Paull, Brett

2014-08-01

Liquid chromatographic assays were developed using a mixed-mode column coupled in sequence with a hydrophilic interaction liquid chromatography column to allow the simultaneous comprehensive analysis of inorganic/organic anions and cations, active pharmaceutical ingredients, and excipients (carbohydrates). The approach utilized dual sample injection and valve-mediated column switching and was based upon a single high-performance liquid chromatography gradient pump. The separation consisted of three distinct sequential separation mechanisms, namely, (i) ion-exchange, (ii) mixed-mode interactions under an applied dual gradient (reversed-phase/ion-exchange), and (iii) hydrophilic interaction chromatography. Upon first injection, the Scherzo SS C18 column (Imtakt) provided resolution of inorganic anions and cations under isocratic conditions, followed by a dual organic/salt gradient to elute active pharmaceutical ingredients and their respective organic counterions and potential degradants. At the top of the mixed-mode gradient (high acetonitrile content), the mobile phase flow was switched to a preconditioned hydrophilic interaction liquid chromatography column, and the standard/sample was reinjected for the separation of hydrophilic carbohydrates, some of which are commonly known excipients in drug formulations. The approach afforded reproducible separation and resolution of up to 23 chemically diverse solutes in a single run. The method was applied to investigate the composition of commercial cough syrups (Robitussin®), allowing resolution and determination of inorganic ions, active pharmaceutical ingredients, excipients, and numerous well-resolved unknown peaks. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gas-liquid interface-mediated room-temperature synthesis of "clean" PdNiP alloy nanoparticle networks with high catalytic activity for ethanol oxidation.

PubMed

Wang, Rongfang; Ma, Yuanyuan; Wang, Hui; Key, Julian; Ji, Shan

2014-11-04

PdNiP alloy nanoparticle networks (PdNiP NN) were prepared by simultaneous reduction of PdCl2, NiCl2 and NaH2PO2 with NaBH4via a gas-liquid interface reaction at room temperature using N2 bubbles. PdNiP NN had markedly higher activity and durability for ethanol oxidation than PdNi nanoparticle networks and PdNiP grain aggregates.

Propulsion Risk Reduction Activities for Non-Toxic Cryogenic Propulsion

NASA Technical Reports Server (NTRS)

Smith, Timothy D.; Klem, Mark D.; Fisher, Kenneth

2010-01-01

The Propulsion and Cryogenics Advanced Development (PCAD) Project s primary objective is to develop propulsion system technologies for non-toxic or "green" propellants. The PCAD project focuses on the development of non-toxic propulsion technologies needed to provide necessary data and relevant experience to support informed decisions on implementation of non-toxic propellants for space missions. Implementation of non-toxic propellants in high performance propulsion systems offers NASA an opportunity to consider other options than current hypergolic propellants. The PCAD Project is emphasizing technology efforts in reaction control system (RCS) thruster designs, ascent main engines (AME), and descent main engines (DME). PCAD has a series of tasks and contracts to conduct risk reduction and/or retirement activities to demonstrate that non-toxic cryogenic propellants can be a feasible option for space missions. Work has focused on 1) reducing the risk of liquid oxygen/liquid methane ignition, demonstrating the key enabling technologies, and validating performance levels for reaction control engines for use on descent and ascent stages; 2) demonstrating the key enabling technologies and validating performance levels for liquid oxygen/liquid methane ascent engines; and 3) demonstrating the key enabling technologies and validating performance levels for deep throttling liquid oxygen/liquid hydrogen descent engines. The progress of these risk reduction and/or retirement activities will be presented.

Propulsion Risk Reduction Activities for Nontoxic Cryogenic Propulsion

NASA Technical Reports Server (NTRS)

Smith, Timothy D.; Klem, Mark D.; Fisher, Kenneth L.

2010-01-01

The Propulsion and Cryogenics Advanced Development (PCAD) Project s primary objective is to develop propulsion system technologies for nontoxic or "green" propellants. The PCAD project focuses on the development of nontoxic propulsion technologies needed to provide necessary data and relevant experience to support informed decisions on implementation of nontoxic propellants for space missions. Implementation of nontoxic propellants in high performance propulsion systems offers NASA an opportunity to consider other options than current hypergolic propellants. The PCAD Project is emphasizing technology efforts in reaction control system (RCS) thruster designs, ascent main engines (AME), and descent main engines (DME). PCAD has a series of tasks and contracts to conduct risk reduction and/or retirement activities to demonstrate that nontoxic cryogenic propellants can be a feasible option for space missions. Work has focused on 1) reducing the risk of liquid oxygen/liquid methane ignition, demonstrating the key enabling technologies, and validating performance levels for reaction control engines for use on descent and ascent stages; 2) demonstrating the key enabling technologies and validating performance levels for liquid oxygen/liquid methane ascent engines; and 3) demonstrating the key enabling technologies and validating performance levels for deep throttling liquid oxygen/liquid hydrogen descent engines. The progress of these risk reduction and/or retirement activities will be presented.

Dual ultrasonic-assisted dispersive liquid-liquid microextraction coupled with microwave-assisted derivatization for simultaneous determination of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol by ultra high performance liquid chromatography-tandem mass spectrometry.

PubMed

Zhao, Xian-En; Lv, Tao; Zhu, Shuyun; Qu, Fei; Chen, Guang; He, Yongrui; Wei, Na; Li, Guoliang; Xia, Lian; Sun, Zhiwei; Zhang, Shijuan; You, Jinmao; Liu, Shu; Liu, Zhiqiang; Sun, Jing; Liu, Shuying

2016-03-11

This paper, for the first time, reported a speedy hyphenated technique of low toxic dual ultrasonic-assisted dispersive liquid-liquid microextraction (dual-UADLLME) coupled with microwave-assisted derivatization (MAD) for the simultaneous determination of 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT). The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection using multiple-reaction monitoring (MRM) mode. A mass spectrometry sensitizing reagent, 4'-carboxy-substituted rosamine (CSR) with high reaction activity and ionization efficiency was synthesized and firstly used as derivatization reagent. Parameters of dual-UADLLME, MAD and UHPLC-MS/MS conditions were all optimized in detail. Low toxic brominated solvents were used as extractant instead of traditional chlorinated solvents. Satisfactory linearity, recovery, repeatability, accuracy and precision, absence of matrix effect and extremely low limits of detection (LODs, 0.010 and 0.015ng/mL for PPD and PPT, respectively) were achieved. The main advantages were rapid, sensitive and environmentally friendly, and exhibited high selectivity, accuracy and good matrix effect results. The proposed method was successfully applied to pharmacokinetics of PPD and PPT in rat plasma. Copyright © 2016 Elsevier B.V. All rights reserved.

Determination of active components of Ginkgo biloba in human urine by capillary high-performance liquid chromatography/mass spectrometry with on-line column-switching purification.

PubMed

Ding, Shujing; Dudley, Ed; Chen, Lijuan; Plummer, Sue; Tang, Jiandong; Newton, Russell P; Brenton, A Gareth

2006-01-01

Ginkgo biloba is one of the most popular herbal nutritional supplements, with terpene lactones and flavonoids being the two major active components. An on-line purification high-performance liquid chromatography/mass spectrometry (HPLC/MS) method was successfully developed for the quantitative determination of flavonoids and terpene lactones excreted in human urine after ingesting the herbal supplement. Satisfactory separation was obtained using a C18 capillary column made in-house with sample clean-up and pre-concentration achieved using a C18 pre-column with column switching. High selectivity and limits of detection of 1-18 ng/mL were achieved using a selected ion monitoring (SIM) scan in negative ion mode; the on-line solid-phase extraction (SPE) recovery of the active components in Ginkgo biloba determined in this study was greater than 75%. Copyright 2006 John Wiley & Sons, Ltd.

Phase relations in the system NaCl-KCl-H2O: V. Thermodynamic-PTX analysis of solid-liquid equilibria at high temperatures and pressures

USGS Publications Warehouse

Sterner, S.M.; Chou, I.-Ming; Downs, R.T.; Pitzer, Kenneth S.

1992-01-01

The Gibbs energies of mixing for NaCl-KCl binary solids and liquids and solid-saturated NaCl-KCl-H2O ternary liquids were modeled using asymmetric Margules treatments. The coefficients of the expressions were calibrated using an extensive array of binary solvus and solidus data, and both binary and ternary liquidus data. Over the PTX range considered, the system exhibits complete liquid miscibility among all three components and extensive solid solution along the anhydrous binary. Solid-liquid and solid-solid phase equilibria were calculated by using the resulting equations and invoking the equality of chemical potentials of NaCl and KCl between appropriate phases at equilibrium. The equations reproduce the ternary liquidus and predict activity coefficients for NaCl and KCl components in the aqueous liquid under solid-saturation conditions between 673 and 1200 K from vapor saturation up to 5 kbar. In the NaCl-KCl anhydrous binary system, the equations describe phase equilibria and predict activity coefficients of the salt components for all stable compositions of solid and liquid phases between room temperature and 1200 K and from 1 bar to 5 kbar. ?? 1992.

Quantitative determination of total cesium in highly active liquid waste by using liquid electrode plasma optical emission spectrometry.

PubMed

Do, Van-Khoai; Yamamoto, Masahiko; Taguchi, Shigeo; Takamura, Yuzuru; Surugaya, Naoki; Kuno, Takehiko

2018-06-01

A sensitive analytical method for determination of total cesium (Cs) in highly active liquid waste (HALW) by using modified liquid electrode plasma optical emission spectrometry (LEP-OES) is developed in this study. The instrument is modified to measure radioactive samples in a glove box. The effects of important factors, including pulsed voltage sequence and nitric acid concentration, on the emission of Cs are investigated. The limit of detection (LOD) and limit of quantification (LOQ) are 0.005 mg/L and 0.02 mg/L, respectively. The achieved LOD is one order lower than that of recently developed spectroscopic methods using liquid discharge plasma. The developed method is validated by subjecting a simulated HALW sample to inductively coupled plasma mass spectrometry (ICP-MS). The recoveries obtained from a spike-and-recovery test are 96-102%, implying good accuracy. The method is successfully applied to the quantification of Cs in a real HALW sample at the Tokai reprocessing plant in Japan. Apart from dilution and filtration of the HALW sample, no other pre-treatment process is required. The results agree well with the values obtained using gamma spectrometry. The developed method offers a reliable technique for rapid analysis of total Cs in HALW samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Viscous liquid film flow on dune slopes of Mars

NASA Astrophysics Data System (ADS)

Möhlmann, Diedrich; Kereszturi, Akos

2010-06-01

It is shown that viscous liquid film flow (VLF-flow) on the surfaces of slopes of martian dunes can be a low-temperature rheological phenomenon active today on high latitudes. A quantitative model indicates that the VLF-flows are consistent with the flow of liquid brines similar to that observed by imaging at the Phoenix landing site. VLF-flows depend on the viscosity, dynamics, and energetics of temporary darkened liquid brines. The darkening of the flowing brine is possibly, at least partially, attributed to non-volatile ingredients of the liquid brines. Evidence of previous VLF-flows can also be seen on the dunes, suggesting that it is an ongoing process that also occurred in the recent past.

Evaluating the Antibacterial Properties of Polyacetylene and Glucosinolate Compounds with Further Identification of Their Presence within Various Carrot (Daucus carota) and Broccoli (Brassica oleracea) Cultivars Using High-Performance Liquid Chromatography with a Diode Array Detector and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry Analyses.

PubMed

Hinds, L; Kenny, O; Hossain, M B; Walsh, D; Sheehy, E; Evans, P; Gaffney, M; Rai, D K

2017-08-23

Ongoing consumer concerns over using synthetic additives in foods has strongly influenced efforts worldwide to source suitable natural alternatives. In this study, the antibacterial efficacy of polyacetylene and glucosinolate compounds was evaluated against both Gram positive and Gram negative bacterial strains. Falcarinol [minimum inhibitory concentration (MIC) = 18.8-37.6 μg/mL] demonstrated the best overall antibacterial activity, while sinigrin (MIC = 46.9-62.5 μg/mL) was the most active glucosinolate compound. High-performance liquid chromatography with a diode array detector analysis showed falcarinol [85.13-244.85 μg/g of dry weight (DW)] to be the most abundant polyacetylene within six of the eight carrot (Daucus carota) cultivars investigated. Meanwhile, sinigrin (100.2-244.3 μg/g of DW) was the most abundant glucosinolate present within the majority of broccoli (Brassica oleracea) cultivars investigated using ultra performance liquid chromatography-tandem mass spectrometry analysis. The high abundance of both falcarinol and sinigrin within these respective species suggests that they could serve as potential sources of natural antibacterial agents for use as such in food products.

Contaminated water treatment

NASA Technical Reports Server (NTRS)

Gormly, Sherwin J. (Inventor); Flynn, Michael T. (Inventor)

2010-01-01

Method and system for processing of a liquid ("contaminant liquid") containing water and containing urine and/or other contaminants in a two step process. Urine, or a contaminated liquid similar to and/or containing urine and thus having a relatively high salt and urea content is passed through an activated carbon filter to provide a resulting liquid, to remove most of the organic molecules. The resulting liquid is passed through a semipermeable membrane from a membrane first side to a membrane second side, where a fortified drink having a lower water concentration (higher osmotic potential) than the resulting liquid is positioned. Osmotic pressure differential causes the water, but not most of the remaining inorganic (salts) contaminant(s) to pass through the membrane to the fortified drink. Optionally, the resulting liquid is allowed to precipitate additional organic molecules before passage through the membrane.

Analysis of major antioxidants from extracts of Myrmecodia pendans by UV/visible spectrophotometer, liquid chromatography/tandem mass spectrometry, and high-performance liquid chromatography/UV techniques.

PubMed

Engida, Adam Mekonnen; Faika, Sitti; Nguyen-Thi, Bich Thuyen; Ju, Yi-Hsu

2015-06-01

In the present work, heat reflux extraction with ethanol/water (80:20; v/v) as the solvent was used to extract antioxidants from Myrmecodia pendans. The crude extract (CE) was fractionated using hexane and ethyl acetate. Ethyl acetate fraction (EAF) and aqueous fraction were collected. Antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power of the CE, EAF, and aqueous fraction were evaluated. EAF showed comparable antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power to those of the CE. UV/visible, liquid chromatography/electrospray ionization/tandem mass spectrometry, and high-performance liquid chromatography were employed for identifying the major antioxidant compounds in the EAF. Three major phenolic compounds (rosmarinic acid, procyanidin B1, and polymer of procyanidin B1) were identified. The first two compounds were confirmed and quantified by high-performance liquid chromatography using authentic standards, but confirmation of the third compound was hampered by a lack of commercial standard. Concentrations of rosmarinic acid and procyanidin B1 in the EAF were found to be 20.688 ± 1.573 mg/g dry sample and 3.236 ± 0.280 mg/g dry sample, respectively. All these three compounds are reported for the first time in sarang semut. Copyright © 2014. Published by Elsevier B.V.

3D pulsed laser-triggered high-speed microfluidic fluorescence-activated cell sorter

PubMed Central

Chen, Yue; Wu, Ting-Hsiang; Kung, Yu-Chun; Teitell, Michael A.; Chiou, Pei-Yu

2014-01-01

We report a 3D microfluidic pulsed laser-triggered fluorescence-activated cell sorter capable of sorting at a throughput of 23,000 cells sec−1 with 90% purity in high-purity mode and at a throughput of 45,000 cells sec−1 with 45% purity in enrichment mode in one stage and in a single channel. This performance is realized by exciting laser-induced cavitation bubbles in a 3D PDMS microfluidic channel to generate high-speed liquid jets that deflect detected fluorescent cells and particles focused by 3D sheath flows. The ultrafast switching mechanism (20 μsec complete on-off cycle), small liquid jet perturbation volume, and three-dimensional sheath flow focusing for accurate timing control of fast (1.5 m sec−1) passing cells and particles are three critical factors enabling high-purity sorting at high-throughput in this sorter. PMID:23844418

Active tuning of high-Q dielectric metasurfaces

DOE PAGES

Parry, Matthew; Komar, Andrei; Hopkins, Ben; ...

2017-08-02

Here, we demonstrate the active tuning of all-dielectric metasurfaces exhibiting high-quality factor (high-Q) resonances. The active control is provided by embedding the asymmetric silicon meta-atoms with liquid crystals, which allows the relative index of refraction to be controlled through heating. It is found that high quality factor resonances (Q = 270 ± 30) can be tuned over more than three resonance widths. Our results demonstrate the feasibility of using all-dielectric metasurfaces to construct tunable narrow-band filters.

Screening bioactive quality control markers of QiShenYiQi dripping pills based on the relationship between the ultra-high performance liquid chromatography fingerprint and vascular protective activity.

PubMed

Zhuo, Limeng; Peng, Jingjing; Zhao, Yunli; Li, Dongxiang; Xie, Xiuman; Tong, Ling; Yu, Zhiguo

2017-10-01

Traditional Chinese medicine consists of complex phytochemical constituents. Selecting appropriate analytical markers of traditional Chinese medicine is a critical step in quality control. Currently, the combination of fingerprinting and efficacy evaluation is considered as a useful method for screening active ingredients in complex mixtures. This study was designed to develop an orthogonal partial least squares model for screening bioactive quality control markers of QishenYiqi dripping pills based on the fingerprint-efficacy relationship. First, the chemical fingerprints of 49 batches of QishenYiqi dripping pill samples were established by ultra-high performance liquid chromatography coupled with a photodiode array detector. Second, ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry was exploited to systematically investigate the 36 copossessing fingerprint components in QishenYiqi dripping pills. The vascular protective activity of QishenYiqi dripping pills was determined by using a cell counting kit-8 assay. Finally, fingerprint-efficacy relationship was established by orthogonal partial least squares model. The results indicated that ten components exhibited strong correlation with vascular protective activity, and these were preliminarily screened as quality control markers. The present study provided a novel idea for the study of the pharmacodynamic material basis and quality evaluation of QishenYiqi dripping pills. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Silica-grafted ionic liquids for revealing the respective charging behaviors of cations and anions in supercapacitors.

PubMed

Dou, Qingyun; Liu, Lingyang; Yang, Bingjun; Lang, Junwei; Yan, Xingbin

2017-12-19

Supercapacitors based on activated carbon electrodes and ionic liquids as electrolytes are capable of storing charge through the electrosorption of ions on porous carbons and represent important energy storage devices with high power delivery/uptake. Various computational and instrumental methods have been developed to understand the ion storage behavior, however, techniques that can probe various cations and anions of ionic liquids separately remain lacking. Here, we report an approach to monitoring cations and anions independently by using silica nanoparticle-grafted ionic liquids, in which ions attaching to silica nanoparticle cannot access activated carbon pores upon charging, whereas free counter-ions can. Aided by this strategy, conventional electrochemical characterizations allow the direct measurement of the respective capacitance contributions and acting potential windows of different ions. Moreover, coupled with electrochemical quartz crystal microbalance, this method can provide unprecedented insight into the underlying electrochemistry.

A Highly Sensitive Resistive Pressure Sensor Based on a Carbon Nanotube-Liquid Crystal-PDMS Composite.

PubMed

Pan, Jin; Liu, Shiyu; Yang, Yicheng; Lu, Jiangang

2018-06-08

Resistive pressure sensors generally employ microstructures such as pores and pyramids in the active layer or on the electrodes to reduce the Young’s modulus and improve the sensitivity. However, such pressure sensors always exhibit complex fabrication process and have difficulties in controlling the uniformity of microstructures. In this paper, we demonstrated a highly sensitive resistive pressure sensor based on a composite comprising of low-polarity liquid crystal (LPLC), multi-walled carbon nanotube (MWCNT), and polydimethylsiloxane (PDMS) elastomer. The LPLC in the PDMS forms a polymer-dispersed liquid crystal (PDLC) structure which can not only reduce the Young’s modulus but also contribute to the construction of conductive paths in the active layer. By optimizing the concentration of LC in PDMS elastomer, the resistive pressure sensor shows a high sensitivity of 5.35 kPa −1 , fast response (<150 ms), and great durability. Fabrication process is also facile and the uniformity of the microstructures can be readily controlled. The pressure sensor offers great potential for applications in emerging wearable devices and electronic skins.

The Inhibitory Effect of Natural Products on Protein Fibrillation May Be Caused by Degradation Products--A Study Using Aloin and Insulin.

PubMed

Lobbens, Eva S; Foderà, Vito; Nyberg, Nils T; Andersen, Kirsten; Jäger, Anna K; Jorgensen, Lene; van de Weert, Marco

2016-01-01

Protein fibrillation is the pathological hallmark of several neurodegenerative diseases and also complicates the manufacturing and use of protein drugs. As a case study, the inhibitory activity of the natural compound aloin against insulin fibrillation was investigated. Based on Thioflavin T assays, high-performance liquid chromatography and transmission electron microscopy it was found that a degradation product of aloin, formed over weeks of storage, was able to significantly inhibit insulin fibrillation. The activity of the stored aloin was significantly reduced in the presence of small amounts of sodium azide or ascorbic acid, suggesting the active compound to be an oxidation product. A high-performance liquid chromatography method and a liquid chromatography-mass spectrometry method were developed to investigate the degradation products in the aged aloin solution. We found that the major compounds in the solution were aloin A and aloin B. In addition, 10-hydroxy aloin and elgonica dimers were detected in smaller amounts. The identified compounds were isolated and tested for activity by means of Thioflavin T assays, but no activity was observed. Thus, the actual fibrillation inhibitor is an as yet unidentified and potentially metastable degradation product of aloin. These results suggest that degradation products, and in particular oxidation products, are to be considered thoroughly when natural products are investigated for activity against protein fibrillation.

Real-time monitoring of glucose-6-phosphate dehydrogenase activity using liquid droplet arrays and its application to human plasma samples.

PubMed

Jung, Se-Hui; Ji, Su-Hyun; Han, Eun-Taek; Park, Won Sun; Hong, Seok-Ho; Kim, Young-Myeong; Ha, Kwon-Soo

2016-05-15

Glucose-6-phosphate dehydrogenase (G6PD) regulates nicotinamide adenine dinucleotide phosphate (NADPH) levels and is related to the pathogenesis of various diseases, including G6PD deficiency, type 2 diabetes, aldosterone-induced endothelial dysfunction, and cancer. Therefore, a highly sensitive array-based assay for determining quantitative G6PD activity is required. Here, we developed an on-chip G6PD activity assay using liquid droplet fluorescence arrays. Quantitative G6PD activity was determined by calculating reduced resorufin concentrations in liquid droplets. The limit of detection (LOD) of this assay was 0.162 mU/ml (2.89 pM), which is much more sensitive than previous assays. We used our activity assay to determine kinetic parameters, including Michaelis-Menten constants (Km) and maximum rates of enzymatic reaction (Vmax) for NADP(+) and G6P, and half-maximal inhibitory concentrations (IC50). We successfully applied this new assay to determine G6PD activity in human plasma from normal healthy individuals (n=30) and patients with inflammation (n=30). The inflammatory group showed much higher G6PD activities than did the normal group (p<0.001), with a high area under the curve value of 0.939. Therefore, this new activity assay has the potential to be used for diagnosis of G6PD-associated diseases and utilizing kinetic studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Antibacterial and cytotoxic activity of isoprenylated coumarin mammea A/AA isolated from Mammea africana.

PubMed

Canning, Corene; Sun, Shi; Ji, Xiangming; Gupta, Smiti; Zhou, Kequan

2013-05-02

The stem bark of Mammea africana is widely distributed in tropical Africa and commonly used in traditional medicine. This study aims to identify the active compound in Mammea africana and to evaluate its antimicrobial and antiproliferative activity. Methanol extract from the bark of the Mammea africana was separated by liquid-liquid extraction, followed by open column chromatography. A principal antimicrobial compound was purified by high performance liquid chromatography (HPLC) and its structure was elucidated by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). The antibacterial activity of the purified compound was determined using the broth microdilution method against 7 common pathogenic bacteria. The compound was also evaluated for cytotoxicity by cell proliferation assay (MTS) using the mouse embryonic fibroblast cell line NIH 3T3 and the non-small cell lung cancer cell line A549. The purified active compound was determined to be mammea A/AA and was found to be highly active against Campylobacter jejuni (MIC=0.5 μg/ml), Streptococcus pneumoniae (MIC=0.25 μg/ml), and Clostridium difficile (MIC=0.25 μg/ml). The compound exhibited significant antiproliferative activities against both NIH 3T3 and A549 cell lines. Mammea A/AA isolated from Mammea africana exerts specific inhibitory activity against Campylobacter jejuni, Streptococcus pneumoniae, and Campylobacter difficile. Mammea A/AA was also found to exhibit significant cytotoxicity against both cancer and normal cell lines. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Tuning the Selectivity of Single-Site Supported Metal Catalysts with Ionic Liquids

DOE PAGES

Babucci, Melike; Fang, Chia -Yu; Hoffman, Adam S.; ...

2017-09-11

1,3-Dialkylimidazolium ionic liquid coatings act as electron donors, increasing the selectivity for partial hydrogenation of 1,3-butadiene catalyzed by iridium complexes supported on high-surface-area γ-Al 2O 3. High-energy-resolution fluorescence detection X-ray absorption near-edge structure (HERFD XANES) measurements quantify the electron donation and are correlated with the catalytic activity and selectivity. Furthermore, the results demonstrate broad opportunities to tune electronic environments and catalytic properties of atomically dispersed supported metal catalysts.

High-performance liquid chromatography analysis of plant saponins: An update 2005-2010

PubMed Central

Negi, Jagmohan S.; Singh, Pramod; Pant, Geeta Joshi Nee; Rawat, M. S. M.

2011-01-01

Saponins are widely distributed in plant kingdom. In view of their wide range of biological activities and occurrence as complex mixtures, saponins have been purified and separated by high-performance liquid chromatography using reverse-phase columns at lower wavelength. Mostly, saponins are not detected by ultraviolet detector due to lack of chromophores. Electrospray ionization mass spectrometry, diode array detector , evaporative light scattering detection, and charged aerosols have been used for overcoming the detection problem of saponins. PMID:22303089

Alkyl(C16, C18, C22)trimethylammonium-Based Herbicidal Ionic Liquids.

PubMed

Pernak, Juliusz; Giszter, Rafał; Biedziak, Agnieszka; Niemczak, Michał; Olszewski, Radosław; Marcinkowska, Katarzyna; Praczyk, Tadeusz

2017-01-18

In the framework of this study a synthesis methodology and characterization of long alkyl herbicidal ionic liquids (HILs) based on four commonly used herbicides (2,4-D, MCPA, MCPP, and dicamba) are presented. New HILs were obtained with high efficiency (>95%) using an acid-base reaction between herbicidal acids and hexadecyltrimethylammonium, octadecyltrimethylammonium, and behenyltrimethylammonium hydroxides in alcoholic medium. Among all synthesized salts, only three compounds comprising the MCPP anion were liquids at room temperature. Subsequently, the influence of both the alkyl chain length and the anion structure on their physicochemical properties (thermal decomposition profiles, solubility in 10 representative solvents, surface activity, density, viscosity, and refractive index) was determined. All HILs exhibited high thermal stability as well as surface activity; however, their solubility notably depended on both the length of the carbon chain and the structure of the anion. The herbicidal efficacy of the obtained salts was tested in greenhouse and field experiments. Greenhouse testing performed on common lambsquarters (Chenopodium album L.) and flixweed (Descurainia sophia L.) as test plants indicated that HILs were characterized by similar or higher efficacy compared to commercial herbicides. The results of field trials confirmed the high activity of HILs, particularly those containing phenoxyacids as anions (MCPA, 2,4-D, and MCPP).

Conformational changes in human Hsp70 induced by high hydrostatic pressure produce oligomers with ATPase activity but without chaperone activity.

PubMed

Araujo, Thaís L S; Borges, Julio Cesar; Ramos, Carlos H; Meyer-Fernandes, José Roberto; Oliveira Júnior, Reinaldo S; Pascutti, Pedro G; Foguel, Debora; Palhano, Fernando L

2014-05-13

We investigated the folding of the 70 kDa human cytosolic inducible protein (Hsp70) in vitro using high hydrostatic pressure as a denaturing agent. We followed the structural changes in Hsp70 induced by high hydrostatic pressure using tryptophan fluorescence, molecular dynamics, circular dichroism, high-performance liquid chromatography gel filtration, dynamic light scattering, ATPase activity, and chaperone activity. Although monomeric, Hsp70 is very sensitive to hydrostatic pressure; after pressure had been removed, the protein did not return to its native sate but instead formed oligomeric species that lost chaperone activity but retained ATPase activity.

Liquid Crystalline Behavior and Related Properties of Colloidal Systems of Inorganic Oxide Nanosheets

PubMed Central

Nakato, Teruyuki; Miyamoto, Nobuyoshi

2009-01-01

Inorganic layered crystals exemplified by clay minerals can be exfoliated in solvents to form colloidal dispersions of extremely thin inorganic layers that are called nanosheets. The obtained “nanosheet colloids” form lyotropic liquid crystals because of the highly anisotropic shape of the nanosheets. This system is a rare example of liquid crystals consisting of inorganic crystalline mesogens. Nanosheet colloids of photocatalytically active semiconducting oxides can exhibit unusual photoresponses that are not observed for organic liquid crystals. This review summarizes experimental work on the phase behavior of the nanosheet colloids as well as photochemical reactions observed in the clay and semiconducting nanosheets system.

Production of 35S for a Liquid Semiconductor Betavoltaic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meier, David E.; Garnov, A. Y.; Robertson, J. D.

2009-10-01

The specific energy density from radioactive decay is five to six orders of magnitude greater than the specific energy density in conventional chemical battery and fuel cell technologies. We are currently investigating the use of liquid semiconductor based betavoltaics as a way to directly convert the energy of radioactive decay into electrical power and potentially avoid the radiation damage that occurs in solid state semiconductor devices due to non-ionizing energy loss. Sulfur-35 was selected as the isotope for the liquid semiconductor demonstrations because it can be produced in high specific activity and it is chemically compatible with known liquid semiconductormore » media.« less

Effect of pressure on viscosity of liquid Fe-alloys up to 16 GPa

NASA Astrophysics Data System (ADS)

Terasaki, H.; Ohtani, E.; Suzuki, A.; Nishida, K.; Sakamaki, T.; Shindo, S.; Funakoshi, K.

2005-12-01

Viscosity of liquid Fe-alloy is closely related to a convection behavior of the Earth's liquid outer core and also time scale of planetary core formation. In previous studies, viscosity of liquid Fe-S has been measured up to 7 GPa using X-ray radiography falling sphere method [Terasaki et al. 2001]. However, some technical problems, such as chemical reaction between the metal marker sphere and the Fe-alloy sample and insufficient image recording time for less viscous material, have been suggested. In this study, we have measured the viscosity of Fe-S and Fe-C liquids without those problems by using novel techniques combined with in situ X-ray radiography falling sphere method and extended the pressure range to 16 GPa. Falling sphere viscometry was carried out under high pressure and temperature using high speed CCD camera with 1500 ton Kawai-type multi-anvil device at BL04B1, SPring-8 in Japan. Starting compositions of Fe-alloy were Fe78S22 and Fe86C14 which correspond to near eutectic compositions at the experimental pressures. Viscosity marker sphere, which was made of Re or Pt, was coated by alumina in order to prevent the reaction between the sphere and the Fe-alloy sample. Falling sphere images were obtained with recording rate of 50 - 125 frame/second. Viscosity of liquid Fe-S was measured up to 16.1 GPa and 1763 K. Measured viscosity coefficients were in the range of 8.8 - 9.2 mPa-s which indicates that the activation volume of viscous flow is approximately a half of the previous estimations (1.5 cm3/mol). Viscosity of liquid Fe-C was measured up to 5 GPa and 1843 K. Viscosity coefficients are 4.7 - 4.9 mPa-s. Activation volume of Fe-C liquid is estimated to be 0.8 cm3/mol. This pressure dependence is consistent with the result of Lucas (1964) measured at ambient pressure. Consequently, viscosity of Fe-alloy liquids are likely to stay small in the Earth's interior and there is no large difference in viscosity coefficient and activation volume between Fe-S and Fe-C eutectic liquids in the range of measurements.

Containerless high temperature property measurements

NASA Technical Reports Server (NTRS)

Nordine, Paul C.; Weber, J. K. Richard; Krishnan, Shankar; Anderson, Collin D.

1991-01-01

Containerless processing in the low gravity environment of space provides the opportunity to increase the temperature at which well controlled processing of and property measurements on materials is possible. This project was directed towards advancing containerless processing and property measurement techniques for application to materials research at high temperatures in space. Containerless high temperature material property studies include measurements of the vapor pressure, melting temperature, optical properties, and spectral emissivities of solid boron. The reaction of boron with nitrogen was also studied by laser polarimetric measurement of boron nitride film growth. The optical properties and spectral emissivities were measured for solid and liquid silicon, niobium, and zirconium; liquid aluminum and titanium; and liquid Ti-Al alloys of 5 to 60 atomic pct. titanium. Alternative means for noncontact temperature measurement in the absence of material emissivity data were evaluated. Also, the application of laser induced fluorescence for component activity measurements in electromagnetic levitated liquids was studied, along with the feasibility of a hybrid aerodynamic electromagnetic levitation technique.

Catalysis of Rice Straw Hydrolysis by the Combination of Immobilized Cellulase from Aspergillus niger on β-Cyclodextrin-Fe3O4 Nanoparticles and Ionic Liquid

PubMed Central

Huang, Po-Jung; Chang, Ken-Lin; Chen, Shui-Tein

2015-01-01

Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride) was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase−1 at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h−1 L−1. One of the advantages of immobilized cellulase is high reusability—it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L−1). Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase. PMID:25874210

Suspensions as a Valuable Alternative to Extemporaneously Compounded Capsules.

PubMed

Dijkers, Eli; Nanhekhan, Valerie; Thorissen, Astrid; Polonini, Hudson

2017-01-01

The objective of this study was to determine the variation in content of 74 different active pharmaceutical ingredients (APIs) and compare it with what is known in the literature for the content uniformity of extemporaneous prepared capsules. Active pharmaceutical ingredients quantification was performed by high-performance liquid chromatography, via a stability-indicating method. Samples for all active pharmaceutical ingredients were taken throughout a 90-day period and the content was determined. In total, 5,190 different samples were analyzed for 74 different active pharmaceutical ingredients at room (15°C to 25°C) or controlled refrigerated temperature (2°C to 8°C). Each of these datasets was analyzed according to the United States Pharmacopeia Content Uniformity monograph, corrected for the sample number. The mean acceptance values were well within specifications. In addition, all suspensions complied with the criteria defined by the British Pharmacopoeia monograph for Content Uniformity of Liquid Dispersions for both room and controlled refrigerated temperature. In previous studies, it was found that a routine weight variation check is often not sufficient for quality assurance of extemporaneous prepared capsules. Compounded oral liquids show little variation in content for 74 different active pharmaceutical ingredients; therefore, compounded oral liquids are a suitable alternative when compounding individualized medications for patients. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Gas chromatography on wall-coated open-tubular columns with ionic liquid stationary phases.

PubMed

Poole, Colin F; Lenca, Nicole

2014-08-29

Ionic liquids have moved from novel to practical stationary phases for gas chromatography with an increasing portfolio of applications. Ionic liquids complement conventional stationary phases because of a combination of thermophysical and solvation properties that only exist for ionic solvents. Their high thermal stability and low vapor pressure makes them suitable as polar stationary phases for separations requiring high temperatures. Ionic liquids are good solvents and can be used to expand the chemical space for separations. They are the only stationary phases with significant hydrogen-bond acidity in common use; they extend the hydrogen-bond basicity of conventional stationary phases; they are as dipolar/polarizable as the most polar conventional stationary phases; and some ionic liquids are significantly less cohesive than conventional polar stationary phases. Problems in column coating techniques and related low column performance, column activity, and stationary phase reactivity require further exploration as the reasons for these features are poorly understood at present. Copyright © 2014 Elsevier B.V. All rights reserved.

New and highly sensitive assay for L-5-hydroxytryptophan decarboxylase activity by high-performance liquid chromatography-voltammetry.

PubMed

Rahman, M K; Nagatsu, T; Kato, T

1980-12-12

This paper describes a new, inexpensive and highly sensitive assay for aromatic L-amino acid decarboxylase (AADC) activity, using L-5-hydroxytryptophan (L-5-HTP) as substrate, in rat and human brains and serum by high-performance liquid chromatography (HPLC) with voltammetric detection. L-5-HTP was used as substrate and D-5-HTP for the blank. After isolating serotonin (5-HT) formed enzymatically from L-5-HTP on a small Amberlite CG-50 column, the 5-HT was eluted with hydrochloric acid and assayed by HPLC with a voltammetric detector. N-Methyldopamine was added to each incubation mixture as an internal standard. This method is sensitive enough to measure 5-HT, formed by the enzyme, 100 fmol to 140 pmol or more. An advantage of this method is that one can incubate the enzyme for longer time (up to 150 min), as compared with AADC assay using L-DOPA as substrate, resulting in a very high sensitivity. By using this new method, AADC activity was discovered in rat serum.

Development of a high-throughput liquid state assay for lipase activity using natural substrates and rhodamine B.

PubMed

Zottig, Ximena; Meddeb-Mouelhi, Fatma; Beauregard, Marc

2016-03-01

A fluorescence-based assay for the determination of lipase activity using rhodamine B as an indicator, and natural substrates such as olive oil, is described. It is based on the use of a rhodamine B-natural substrate emulsion in liquid state, which is advantageous over agar plate assays. This high-throughput method is simple and rapid and can be automated, making it suitable for screening and metagenomics application. Reaction conditions such as pH and temperature can be varied and controlled. Using triolein or olive oil as a natural substrate allows monitoring of lipase activity in reaction conditions that are closer to those used in industrial settings. The described method is sensitive over a wide range of product concentrations and offers good reproducibility. Copyright © 2015 Elsevier Inc. All rights reserved.

High performance liquid chromatography method for the determination of cinnamyl alcohol dehydrogenase activity in soybean roots.

PubMed

dos Santos, W D; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, O

2006-01-01

This study proposes a simple, quick and reliable method for determining the cinnamyl alcohol dehydrogenase (CAD; EC 1.1.1.195) activity in soybean (Glycine max L. Merr.) roots using reversed-phase high performance liquid chromatography (RP-HPLC). The method includes a single extraction of the tissue and conduction of the enzymatic reaction at 30 degrees C with cinnamaldehydes (coniferyl or sinapyl), substrates of CAD. Disappearance of the substrates in the reaction mixture is monitored at 340 nm (for coniferaldehyde) or 345 nm (for sinapaldehyde) by isocratic elution with methanol/acetic acid through a GLC-ODS (M) column. This HPLC technique furnishes a rapid and reliable measure of cinnamaldehyde substrates, and may be used as an alternative tool to analyze CAD activity in enzyme preparation without previous purification.

[The pharmacokinetics of the dipeptide analog of piracetam with nootropic activity GVS-111 and of its basic metabolites].

PubMed

Boĭko, S S; Zherdev, V P; Dvorianinov, A A; Gudasheva, T A; Ostrovskaia, R U; Voronina, T A; Rozantsev, G G; Seredenin, S B

1997-01-01

The pharmacokinetics of a new nootropic dipeptide analog of piracetam-N-phenylacetyl-L-prolylglycine (GWS-111) and its main metabolites were studied in rats by means of high performance liquid chromatography and gas-liquid chromatography. The compound under study showed a greater resistance to an enzymatic effect than natural neuropeptides. In addition to an unchanged compound three of its metabolites were found in the blood plasma of the rats. One of them, cyclo-Pro-Gly was an active metabolite of GWS-111.

High Performance Liquid Chromatography-Diode Array Detector Method for the Simultaneous Determination of Five Compounds in the Pulp and Seed of Sea Buckthorn.

PubMed

Zhao, Lu; Wen, E; Upur, Halmuart; Tian, Shuge

2017-01-01

Sea buckthorn ( Hippophae rhamnoides L.) as a traditional Chinese medicinal plant has various uses in Xinjiang. A reversed-phase rapid-resolution liquid-chromatography method with diode array detector was developed for simultaneous determination of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the pulp and seed of sea buckthorn, a widely used traditional Chinese medicine for promoting metabolism and treating scurvy and other diseases. Compounds were separated on an Agilent ZORBAX SB-C18 column (4.6 mm × 250 mm, 5 μm; USA) with gradient elution using methanol and 0.4% phosphoric acid (v/v) at 1.0 mL/min. Detection wavelength was set at 280 nm. The fruits of wild sea buckthorn were collected from Wushi County in Aksu, Xinjiang Province. The RSD of precision test of the five compounds were in the range of 0.60-2.22%, and the average recoveries ranged from 97.36% to 101.19%. Good linearity between specific chromatographic peak and component qualities were observed in the investigated ranges for all the analytes ( R 2 > 0.9997). The proposed method was successfully applied to determine the levels of five active components in sea buckthorn samples from Aksu in Xinjiang. The proposed method is simple, fast, sensitive, accurate, and suitable for quantitative assessment of the pulp and seed of sea buckthorn. Quantitative analysis method of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the extract of sea buckthorn pulp and seed is developed by high-performance liquid chromatography (HPLC) diode array detection.This method is simple and accurate; has strong specificity, good precision, and high recovery rate; and provides a reliable basis for further development of the substances in the pulp and seed of sea buckthorn.The method is widely used for content determination of active ingredients or physiologically active components in traditional Chinese medicine and its preparation Abbreviation used: PR: protocatechuic acid, RU: rutin, QU: quercetin, KA: kaempferol, IS: isorhamnetin, HPLC: high-performance liquid chromatography, HPLC-DAD: high performance liquid chromatographydiode array detector, LOD: linearity and limit of detection, LOQ: limit of quantitation, RSD: relative standard deviation.

Thermodynamic Modeling of Organic-Inorganic Aerosols with the Group-Contribution Model AIOMFAC

NASA Astrophysics Data System (ADS)

Zuend, A.; Marcolli, C.; Luo, B. P.; Peter, T.

2009-04-01

Liquid aerosol particles are - from a physicochemical viewpoint - mixtures of inorganic salts, acids, water and a large variety of organic compounds (Rogge et al., 1993; Zhang et al., 2007). Molecular interactions between these aerosol components lead to deviations from ideal thermodynamic behavior. Strong non-ideality between organics and dissolved ions may influence the aerosol phases at equilibrium by means of liquid-liquid phase separations into a mainly polar (aqueous) and a less polar (organic) phase. A number of activity models exists to successfully describe the thermodynamic equilibrium of aqueous electrolyte solutions. However, the large number of different, often multi-functional, organic compounds in mixed organic-inorganic particles is a challenging problem for the development of thermodynamic models. The group-contribution concept as introduced in the UNIFAC model by Fredenslund et al. (1975), is a practical method to handle this difficulty and to add a certain predictability for unknown organic substances. We present the group-contribution model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients), which explicitly accounts for molecular interactions between solution constituents, both organic and inorganic, to calculate activities, chemical potentials and the total Gibbs energy of mixed systems (Zuend et al., 2008). This model enables the computation of vapor-liquid (VLE), liquid-liquid (LLE) and solid-liquid (SLE) equilibria within one framework. Focusing on atmospheric applications we considered eight different cations, five anions and a wide range of alcohols/polyols as organic compounds. With AIOMFAC, the activities of the components within an aqueous electrolyte solution are very well represented up to high ionic strength. We show that the semi-empirical middle-range parametrization of direct organic-inorganic interactions in alcohol-water-salt solutions enables accurate computations of vapor-liquid and liquid-liquid equilibria. References Fredenslund, A., Jones, R. L., and Prausnitz, J. M.: Group-Contribution Estimation of Activity Coefficients in Nonideal Liquid Mixtures, AIChE J., 21, 1086-1099, 1975. Rogge, W. F., Mazurek, M. A., Hildemann, L. M., Cass, G. R., and Simoneit, B. R. T.: Quantification of Urban Organic Aerosols at a Molecular Level: Identification, Abundance and Seasonal Variation, Atmos. Environ., 27, 1309-1330, 1993. Zhang, Q. et al.: Ubiquity and dominance of oxygenated species in organic aerosols in anthropogenically influenced Northern Hemisphere midlatitudes, Geophys. Res. Lett., 34, L13 801, 2007. Zuend, A., Marcolli, C., Luo, B. P., and Peter, T.: A thermodynamic model of mixed organic-inorganic aerosols to predict activity coefficients, Atmos. Chem. Phys., 8, 4559-4593, 2008.

Steady-state studies of the reactions of H2O-CO and CO2-H2 mixtures with liquid iron

NASA Astrophysics Data System (ADS)

Sasaki, Y.; Belton, G. R.

1998-08-01

Studies have been made of the steady-stata composition of liquid iron exposed to high flow rates of H2O-CO mixtures at 1550 °C to 1700 °C and CO2-H2 mixtures at 1600 °C. Values of the steady-state activity of oxygen have been established by measurement of either the carbon concentration or the silicon concentration when the iron was held in a silica crucible. Additions of sulfur or selenium to the iron have been found to result in steady-state oxygen activities, which differ significantly from those expected from water-gas equilibrium. The results are interpreted to show that the ratio of the apparent first-order rate constants for the reactions of H2O and CO2 with liquid iron is about 3 at 1600 °C. It is shown that the dependencies of the rate constants on the activities of sulfur, oxygen, and selenium must, even if complex, be similar for the H2O and CO2 reactions with liquid iron, to a good approximation.

Diversity and relationships in key traits for functional and apparent quality in a collection of eggplant: fruit phenolics content, antioxidant activity, polyphenol oxidase activity, and browning.

PubMed

Plazas, Mariola; López-Gresa, María P; Vilanova, Santiago; Torres, Cristina; Hurtado, Maria; Gramazio, Pietro; Andújar, Isabel; Herráiz, Francisco J; Bellés, José M; Prohens, Jaime

2013-09-18

Eggplant (Solanum melongena) varieties with increased levels of phenolics in the fruit present enhanced functional quality, but may display greater fruit flesh browning. We evaluated 18 eggplant accessions for fruit total phenolics content, chlorogenic acid content, DPPH scavenging activity, polyphenol oxidase (PPO) activity, liquid extract browning, and fruit flesh browning. For all the traits we found a high diversity, with differences among accessions of up to 3.36-fold for fruit flesh browning. Variation in total content in phenolics and in chlorogenic acid content accounted only for 18.9% and 6.0% in the variation in fruit flesh browning, and PPO activity was not significantly correlated with fruit flesh browning. Liquid extract browning was highly correlated with chlorogenic acid content (r = 0.852). Principal components analysis (PCA) identified four groups of accessions with different profiles for the traits studied. Results suggest that it is possible to develop new eggplant varieties with improved functional and apparent quality.

Simultaneous quantification of preactivated ifosfamide derivatives and of 4-hydroxyifosfamide by high performance liquid chromatography-tandem mass spectrometry in mouse plasma and its application to a pharmacokinetic study.

PubMed

Deroussent, Alain; Skarbek, Charles; Maury, Adeline; Chapuis, Hubert; Daudigeos-Dubus, Estelle; Le Dret, Ludivine; Durand, Sylvère; Couvreur, Patrick; Desmaële, Didier; Paci, Angelo

2015-06-15

The antitumor drug, ifosfamide (IFO), requires activation by cytochrome P450 (CYP) to form the active metabolite, 4-hydroxyisfosfamide (4-OHIFO), leading to toxic by-products at high dose. In order to overcome these drawbacks, preactivated ifosfamide derivatives (RXIFO) were designed to release 4-OHIFO without CYP involvement. A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous quantification of 4-OHIFO, IFO and four derivatives RXIFO in mouse plasma using multiple reaction monitoring. Because of its instability in plasma, 4-OHIFO was immediately converted to the semi-carbazone derivative, 4-OHIFO-SCZ. For the six analytes, the calibration curves were linear from 20 to 5000ng/mL in 50μL plasma and the lower limit of quantitation was determined at 20ng/mL with accuracies within ±10% of nominal and precisions less than 12%. Their recoveries ranged from 62 to 96% by using liquid-liquid extraction. With an improved assay sensitivity compared to analogues, the derivative 4-OHIFO-SCZ was stable in plasma at 4°C for 24h and at -20°C for three months. For all compounds, the assay was validated with accuracies within ±13% and precisions less than 15%. This method was applied to a comparative pharmacokinetic study of 4-OHIFO from IFO and three derivatives RXIFO in mice. This active metabolite was produced by some of the novel conjugates with good pharmacokinetic properties. Copyright © 2015 Elsevier B.V. All rights reserved.

Amorphizing of Cu Nanoparticles toward Highly Efficient and Robust Electrocatalyst for CO2 Reduction to Liquid Fuels with High Faradaic Efficiencies.

PubMed

Duan, Yan-Xin; Meng, Fan-Lu; Liu, Kai-Hua; Yi, Sha-Sha; Li, Si-Jia; Yan, Jun-Min; Jiang, Qing

2018-04-01

Conversion of carbon dioxide (CO 2 ) into valuable chemicals, especially liquid fuels, through electrochemical reduction driven by sustainable energy sources, is a promising way to get rid of dependence on fossil fuels, wherein developing of highly efficient catalyst is still of paramount importance. In this study, as a proof-of-concept experiment, first a facile while very effective protocol is proposed to synthesize amorphous Cu NPs. Unexpectedly, superior electrochemical performances, including high catalytic activity and selectivity of CO 2 reduction to liquid fuels are achieved, that is, a total Faradaic efficiency of liquid fuels can sum up to the maximum value of 59% at -1.4 V, with formic acid (HCOOH) and ethanol (C 2 H 6 O) account for 37% and 22%, respectively, as well as a desirable long-term stability even up to 12 h. More importantly, this work opens a new avenue for improved electroreduction of CO 2 based on amorphous metal catalysts. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Separation of three anthraquinone glycosides including two isomers by preparative high-performance liquid chromatography and high-speed countercurrent chromatography from Rheum tanguticum Maxim. ex Balf.

PubMed

Chen, Tao; Li, Hongmei; Zou, Denglang; Liu, Yongling; Chen, Chen; Zhou, Guoying; Li, Yulin

2016-08-01

Anthraquinone glycosides, such as chrysophanol 1-O-β-d-glucoside, chrysophanol 8-O-β-d-glucoside, and physion 8-O-β-d-glucoside, are the accepted important active components of Rheum tanguticum Maxim. ex Balf. due to their pharmacological properties: antifungal, antimicrobial, cytotoxic, and antioxidant activities. However, an effective method for the separation of the above-mentioned anthraquinone glycosides from this herb is not currently available. Especially, greater difficulty existed in the separation of the two isomers chrysophanol 1-O-β-d-glucoside and chrysophanol 8-O-β-d-glucoside. This study demonstrated an efficient strategy based on preparative high-performance liquid chromatography and high-speed countercurrent chromatography for the separation of the above-mentioned anthraquinone glycosides from Rheum tanguticum Maxim.ex Balf. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plastic catalytic pyrolysis to fuels as tertiary polymer recycling method: effect of process conditions.

PubMed

Gulab, Hussain; Jan, Muhammad Rasul; Shah, Jasmin; Manos, George

2010-01-01

This paper presents results regarding the effect of various process conditions on the performance of a zeolite catalyst in pyrolysis of high density polyethylene. The results show that polymer catalytic degradation can be operated at relatively low catalyst content reducing the cost of a potential industrial process. As the polymer to catalyst mass ratio increases, the system becomes less active, but high temperatures compensate for this activity loss resulting in high conversion values at usual batch times and even higher yields of liquid products due to less overcracking. The results also show that high flow rate of carrier gas causes evaporation of liquid products falsifying results, as it was obvious from liquid yield results at different reaction times as well as the corresponding boiling point distributions. Furthermore, results are presented regarding temperature effects on liquid selectivity. Similar values resulted from different final reactor temperatures, which are attributed to the batch operation of the experimental equipment. Since polymer and catalyst both undergo the same temperature profile, which is the same up to a specific time independent of the final temperature. Obviously, this common temperature step determines the selectivity to specific products. However, selectivity to specific products is affected by the temperature, as shown in the corresponding boiling point distributions, with higher temperatures showing an increased selectivity to middle boiling point components (C(8)-C(9)) and lower temperatures increased selectivity to heavy components (C(14)-C(18)).

Fingerprint analysis and quality consistency evaluation of flavonoid compounds for fermented Guava leaf by combining high-performance liquid chromatography time-of-flight electrospray ionization mass spectrometry and chemometric methods.

PubMed

Wang, Lu; Tian, Xiaofei; Wei, Wenhao; Chen, Gong; Wu, Zhenqiang

2016-10-01

Guava leaves are used in traditional herbal teas as antidiabetic therapies. Flavonoids are the main active of Guava leaves and have many physiological functions. However, the flavonoid compositions and activities of Guava leaves could change due to microbial fermentation. A high-performance liquid chromatography time-of-flight electrospray ionization mass spectrometry method was applied to identify the varieties of the flavonoids in Guava leaves before and after fermentation. High-performance liquid chromatography, hierarchical cluster analysis and principal component analysis were used to quantitatively determine the changes in flavonoid compositions and evaluate the consistency and quality of Guava leaves. Monascus anka Saccharomyces cerevisiae fermented Guava leaves contained 2.32- and 4.06-fold more total flavonoids and quercetin, respectively, than natural Guava leaves. The flavonoid compounds of the natural Guava leaves had similarities ranging from 0.837 to 0.927. The flavonoid compounds from the Monascus anka S. cerevisiae fermented Guava leaves had similarities higher than 0.993. This indicated that the quality consistency of the fermented Guava leaves was better than that of the natural Guava leaves. High-performance liquid chromatography fingerprinting and chemometric analysis are promising methods for evaluating the degree of fermentation of Guava leaves based on quality consistency, which could be used in assessing flavonoid compounds for the production of fermented Guava leaves. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Creation of energetic biothermite inks using ferritin liquid protein

NASA Astrophysics Data System (ADS)

Slocik, Joseph M.; McKenzie, Ruel; Dennis, Patrick B.; Naik, Rajesh R.

2017-04-01

Energetic liquids function mainly as fuels due to low energy densities and slow combustion kinetics. Consequently, these properties can be significantly increased through the addition of metal nanomaterials such as aluminium. Unfortunately, nanoparticle additives are restricted to low mass fractions in liquids because of increased viscosities and severe particle agglomeration. Nanoscale protein ionic liquids represent multifunctional solvent systems that are well suited to overcoming low mass fractions of nanoparticles, producing stable nanoparticle dispersions and simultaneously offering a source of oxidizing agents for combustion of reactive nanomaterials. Here, we use iron oxide-loaded ferritin proteins to create a stable and highly energetic liquid composed of aluminium nanoparticles and ferritin proteins for printing and forming 3D shapes and structures. In total, this bioenergetic liquid exhibits increased energy output and performance, enhanced dispersion and oxidation stability, lower activation temperatures, and greater processability and functionality.

Wick-and-pool electrodes for electrochemical cell

DOEpatents

Roche, Michael F.; Faist, Suzan M.; Eberhart, James G.; Ross, Laurids E.

1977-01-01

An electrode system includes a reservoir of liquid-metal reactant, and a wick extending from a submersed location within the reservoir into the molten electrolyte of an electrochemical cell structure. The wick is flooded with the liquid metal and thereby serves as one electrode within the cell. This electrode system has application in high-temperature batteries employing molten alkali metals or their alloys as active material within an electrode submersed within a molten salt electrolyte. It also can be used in electrochemical cells where the purification, separation or electrowinning of liquid metals is accomplished.

Wick-and-pool electrodes for electrochemical cell

DOEpatents

Roche, Michael F.; Faist, Suzan M.; Eberhart, James G.; Ross, Laurids E.

1980-01-01

An electrode system includes a reservoir of liquid-metal reactant, and a wick extending from a submersed location within the reservoir into the molten electrolyte of an electrochemical cell structure. The wick is flooded with the liquid metal and thereby serves as one electrode within the cell. This electrode system has application in high-temperature batteries employing molten alkali metals or their alloys as active material within an electrode submersed within a molten salt electrolyte. It also can be used in electrochemical cells where the purification, separation or electrowinning of liquid metals is accomplished.

Comparing the catalytic oxidation of ethanol at the solid-gas and solid-liquid interfaces over size-controlled Pt nanoparticles: striking differences in kinetics and mechanism.

PubMed

Sapi, Andras; Liu, Fudong; Cai, Xiaojun; Thompson, Christopher M; Wang, Hailiang; An, Kwangjin; Krier, James M; Somorjai, Gabor A

2014-11-12

Pt nanoparticles with controlled size (2, 4, and 6 nm) are synthesized and tested in ethanol oxidation by molecular oxygen at 60 °C to acetaldehyde and carbon dioxide both in the gas and liquid phases. The turnover frequency of the reaction is ∼80 times faster, and the activation energy is ∼5 times higher at the gas-solid interface compared to the liquid-solid interface. The catalytic activity is highly dependent on the size of the Pt nanoparticles; however, the selectivity is not size sensitive. Acetaldehyde is the main product in both media, while twice as much carbon dioxide was observed in the gas phase compared to the liquid phase. Added water boosts the reaction in the liquid phase; however, it acts as an inhibitor in the gas phase. The more water vapor was added, the more carbon dioxide was formed in the gas phase, while the selectivity was not affected by the concentration of the water in the liquid phase. The differences in the reaction kinetics of the solid-gas and solid-liquid interfaces can be attributed to the molecular orientation deviation of the ethanol molecules on the Pt surface in the gas and liquid phases as evidenced by sum frequency generation vibrational spectroscopy.

A chemically regenerative redox fuel cell using (2,2,6,6-tetramethylpiperidin-1-yl)oxyl redox reaction in acid medium

NASA Astrophysics Data System (ADS)

Han, Sang-Beom; Kwak, Da-Hee; Park, Hyun Suk; Park, Jin-Young; Ma, Kyeng-Bae; Won, Ji-Eun; Kim, Do-Hyoung; Kim, Min-Cheol; Park, Kyung-Won

2018-07-01

(2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) with no free radical and non-volatile characteristic can be utilized as a liquid catalyst instead of O2 at the cathode in a chemical regenerative redox fuel cell with H2 as a fuel at the anode. In this study, the electrochemical properties and performance of TEMPO dissolved in sulfuric acid solution are investigated using half and unit cells. In the half-cell, TEMPO shows an activation energy of 1.27 kcal mol-1 K-1 for the reduction. A chemical regenerative redox fuel cell (CRRFC) using TEMPO as the liquid catalyst exhibits an open circuit voltage of 0.7 V and a maximum power density of 90 mW cm-2 at 30 °C with a low activation loss. The regeneration cycling test of the CRRFC is performed at a constant voltage of 0.4 V under a flow rate of the oxygen-bubbled TEMPO solution. The performance of the CRRFC deteriorates, i.e., a power density of zero measured at >200 min. Thus, a highly efficient regeneration system needs to be developed for a high-performance CRRFC using TEMPO used as a liquid-type oxidant. Furthermore, stable liquid oxidants with relatively high standard reduction potentials can be proposed through various organic compounds.

Charge Density Dependent Hole Mobility and Density of States Throughout the Entire Finite Potential Window of Conductivity in Ionic Liquid Gated Poly(3-hexylthiophene)

NASA Astrophysics Data System (ADS)

Paulsen, Bryan D.; Frisbie, C. Daniel

2012-02-01

Ionic liquids, used in place of traditional gate dielectric materials, allow for the accumulation of very high 2D and 3D charge densities (>10^14 #/cm^2 and >10^21 #/cm^3 respectively) at low voltage (<5 V). Here we study the electrochemical gating of the benchmark semiconducting polymer poly(3-hexylthiophene) (P3HT) with the ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([EMI][FAP]). The electrochemical stability of [EMI][FAP] allowed the reproducible accumulation of 2 x 10^21 hole/cm^3, or one hole (and stabilizing anion dopant) per every two thiophene rings. A finite potential/charge density window of high electrical conductivity was observed with hole mobility reaching a maximum of 0.86 cm^2/V s at 0.12 holes per thiophene ring. Displacement current measurements, collected versus a calibrated reference electrode, allowed the mapping of the highly structured and extremely broad density of states of the P3HT/[EMI][FAP] doped composite. Variable temperature and charge density hole transport measurements revealed hole transport to be thermally activated and non-monotonic, displaying a activation energy minimum of ˜20 meV in the region of maximum conductivity and hole mobility. To show the generality of this result, the study was extended to an additional four ionic liquids and three semiconducting polymers.

ENZYMATIC POLYMERIZATION OF PHENOLS IN ROOM TEMPERATURE IONIC LIQUIDS

PubMed Central

Eker, Bilge; Zagorevski, Dmitri; Zhu, Guangyu; Linhardt, Robert J.; Dordick, Jonathan S.

2009-01-01

Soybean peroxidase (SBP) was used to catalyze the polymerization of phenols in room-temperature ionic liquids (RTILs). Phenolic polymers with number average molecular weights ranging from 1200 to 4100 D were obtained depending on the composition of the reaction medium and the nature of the phenol. Specifically, SBP was highly active in methylimidazolium-containing RTILs, including 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(BF4)), and 1-butyl-3-methylpyridinium tetrafluoroborate (BMPy(BF4)) with the ionic liquid content as high as 90% (v/v); the balance being aqueous buffer. Gel permeation chromatography and MALDI-TOF analysis indicated that higher molecular weight polymers can be synthesized in the presence of higher RTIL concentrations, with selective control over polymer size achieved by varying the RTIL concentration. The resulting polyphenols exhibited high thermostability and possessed thermosetting properties. PMID:20161409

Enhanced Densification of PM Steels by Liquid Phase Sintering with Boron-Containing Master Alloy

NASA Astrophysics Data System (ADS)

Vattur Sundaram, Maheswaran; Surreddi, Kumar Babu; Hryha, Eduard; Veiga, Angela; Berg, Sigurd; Castro, Fransisco; Nyborg, Lars

2018-01-01

Reaching high density in PM steels is important for high-performance applications. In this study, liquid phase sintering of PM steels by adding gas-atomized Ni-Mn-B master alloy was investigated for enhancing the density levels of Fe- and Mo- prealloyed steel powder compacts. The results indicated that liquid formation occurs in two stages, beginning with the master alloy melting (LP-1) below and eutectic phase formation (LP-2) above 1373 K (1100 °C). Mo and C addition revealed a significant influence on the LP-2 temperatures and hence on the final densification behavior and mechanical properties. Microstructural embrittlement occurs with the formation of continuous boride networks along the grain boundaries, and its severity increases with carbon addition, especially for 2.5 wt pct of master alloy content. Sintering behavior, along with liquid generation, microstructural characteristics, and mechanical testing revealed that the reduced master alloy content from 2.5 to 1.5 wt pct (reaching overall boron content from 0.2 to 0.12 wt pct) was necessary for obtaining good ductility with better mechanical properties. Sintering with Ni-Mn-B master alloy enables the sintering activation by liquid phase formation in two stages to attain high density in PM steels suitable for high-performance applications.

Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gangwal, Santosh K.; McCabe, Kevin

2015-04-30

The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifiermore » (TRIG TM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H 2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.« less

Photocatalytic Activity of Nanotubular TiO2 Films Obtained by Anodic Oxidation: A Comparison in Gas and Liquid Phase

PubMed Central

Sanabria Arenas, Beatriz Eugenia; Schiavi, Luca; Russo, Valeria; Pedeferri, MariaPia

2018-01-01

The availability of immobilized nanostructured photocatalysts is of great importance in the purification of both polluted air and liquids (e.g., industrial wastewaters). Metal-supported titanium dioxide films with nanotubular morphology and good photocatalytic efficiency in both environments can be produced by anodic oxidation, which avoids release of nanoscale materials in the environment. Here we evaluate the effect of different anodizing procedures on the photocatalytic activity of TiO2 nanostructures in gas and liquid phases, in order to identify the most efficient and robust technique for the production of TiO2 layers with different morphologies and high photocatalytic activity in both phases. Rhodamine B and toluene were used as model pollutants in the two media, respectively. It was found that the role of the anodizing electrolyte is particularly crucial, as it provides substantial differences in the oxide specific surface area: nanotubular structures show remarkably different activities, especially in gas phase degradation reactions, and within nanotubular structures, those produced by organic electrolytes lead to better photocatalytic activity in both conditions tested. PMID:29587360

Self-diffusion and microscopic dynamics in a gold-silicon liquid investigated with quasielastic neutron scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evenson, Zach, E-mail: Zachary.Evenson@frm2.tum.de; Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt; Yang, Fan

2016-03-21

We use incoherent quasielastic neutron scattering to study the atomic dynamics of gold in a eutectic Au{sub 81}Si{sub 19} melt. Despite the glass-forming nature of this system, the gold self-diffusivity displays an Arrhenius behavior with a low activation energy characteristic of simple liquids. At high temperatures, long-range transport of gold atoms is well described by hydrodynamic theory with a simple exponential decay of the self-correlation function. On cooling towards the melting temperature, structural relaxation crosses over to a highly stretched exponential behavior. This suggests the onset of a heterogeneous dynamics, even in the equilibrium melt, and is indicative of amore » very fragile liquid.« less

Development of Plastic Substrate Technology for Active Matrix Liquid Crystal Displays Final Report CRADA No. TC-761-93

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carey, P.; Kamath, H.

Raychem Corporation (RYC) and the Lawrence Livermore National Laboratory (LLNL) conducted a development program with the goal to make rugged, low-cost., high-resolution flat panel displays based on RYC's proprietary Nematic Curvilinear Aligned Phase (NCAP) liquid crystal and LLNL's patented processes for the formation and doping of polycrystalline silicon on low-temperature, flexible, plastic substrates.

Observations and implications of liquid–liquid phase separation at high relative humidities in secondary organic material produced by α-pinene ozonolysis without inorganic salts

DOE PAGES

Renbaum-Wolff, Lindsay; Song, Mijung; Marcolli, Claudia; ...

2016-07-01

Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. In order to predict the role of these particles in climate, visibility and atmospheric chemistry, information on particle phase state (i.e., single liquid, two liquids and solid) is needed. Our paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated in the laboratory using optical microscopy and theoretically using a thermodynamic model at 290 K and for relative humidities ranging from < 0.5 to 100%. In the laboratory studies, a single phase was observed frommore » 0 to 95% relative humidity (RH) while two liquid phases were observed above 95% RH. For increasing RH, the mechanism of liquid–liquid phase separation (LLPS) was spinodal decomposition. The RH range over which two liquid phases were observed did not depend on the direction of RH change. In the modeling studies, the SOM took up very little water and was a single organic-rich phase at low RH values. At high RH, the SOM underwent LLPS to form an organic-rich phase and a water-rich phase, consistent with the laboratory studies. The presence of LLPS at high RH values can have consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima were observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. Recently researchers have observed inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation (i.e., hygroscopic parameters measured below water saturation were inconsistent with hygroscopic parameters measured above water saturation). Furthermore, the work presented here illustrates that such inconsistencies are expected for systems with LLPS when the water uptake at subsaturated conditions represents the hygroscopicity of an organic-rich phase while the barrier for CCN activation can be determined by the second maximum in the Köhler curve when the particles are water rich.« less

Mixed cryogen cooling systems for HTS power applications: A status report of progress in Korea University

NASA Astrophysics Data System (ADS)

Song, Jung-Bin; Lee, Haigun

2012-12-01

A cooling system employing a solid cryogen (SC), such as solid nitrogen (SN2), was recently reported for high-temperature superconducting (HTS) applications. However, thermal contact between the SC and the HTS can be degraded by repeated overcurrent runs, resulting in 'thermal dry-out'. Novel cryogens, SC with small amounts of liquid cryogen, have been suggested to overcome this problem. Such cooling systems rely on the small amount of liquid cryogen to facilitate heat exchange so as to fully exploit the heat capacity of the solid cryogen. This paper presents a description and summary of recent activities at Korea University related to cooling systems employing mixed cryogens of solid-liquid nitrogen, solid argon-liquid nitrogen, and solid nitrogen-liquid neon.

High-performance liquid chromatographic characterization of some medical plant extracts used in cosmetic formulas.

PubMed

Schulz, H; Albroscheit, G

1988-06-17

Rapid and reliable methods are presented for the characterization of biologically active and/or characteristic constituents in aqueous extracts of Hamamelis virginiana, Matricaria chamomilla, Achillea millefolium, Thymus vulgaris, Althaea officinalis and Cinchonia spp. Prior to high-performance liquid chromatographic (HPLC) separation a clean-up step was performed using a solid-phase extraction system. The purified extracts were analysed by HPLC coupled with a diode-array detector and a fluorescence detector. In some instances, previously unreported components of the aqueous plant extracts were found.

A molecular nematic liquid crystalline material for high-performance organic photovoltaics

PubMed Central

Sun, Kuan; Xiao, Zeyun; Lu, Shirong; Zajaczkowski, Wojciech; Pisula, Wojciech; Hanssen, Eric; White, Jonathan M.; Williamson, Rachel M.; Subbiah, Jegadesan; Ouyang, Jianyong; Holmes, Andrew B.; Wong, Wallace W.H.; Jones, David J.

2015-01-01

Solution-processed organic photovoltaic cells (OPVs) hold great promise to enable roll-to-roll printing of environmentally friendly, mechanically flexible and cost-effective photovoltaic devices. Nevertheless, many high-performing systems show best power conversion efficiencies (PCEs) with a thin active layer (thickness is ~100 nm) that is difficult to translate to roll-to-roll processing with high reproducibility. Here we report a new molecular donor, benzodithiophene terthiophene rhodanine (BTR), which exhibits good processability, nematic liquid crystalline behaviour and excellent optoelectronic properties. A maximum PCE of 9.3% is achieved under AM 1.5G solar irradiation, with fill factor reaching 77%, rarely achieved in solution-processed OPVs. Particularly promising is the fact that BTR-based devices with active layer thicknesses up to 400 nm can still afford high fill factor of ~70% and high PCE of ~8%. Together, the results suggest, with better device architectures for longer device lifetime, BTR is an ideal candidate for mass production of OPVs. PMID:25586307

A step toward the development of high-temperature stable ionic liquid-in-oil microemulsions containing double-chain anionic surface active ionic liquid.

PubMed

Rao, Vishal Govind; Banerjee, Chiranjib; Ghosh, Surajit; Mandal, Sarthak; Kuchlyan, Jagannath; Sarkar, Nilmoni

2013-06-20

Owing to their fascinating properties and wide range of potential applications, interest in nonaqueous microemulsions has escalated in the past decade. In the recent past, nonaqueous microemulsions containing ionic liquids (ILs) have been utilized in performing chemical reactions, preparation of nanomaterials, synthesis of nanostructured polymers, and drug delivery systems. The most promising fact about IL-in-oil microemulsions is their high thermal stability compared to that of aqueous microemulsions. Recently, surfactant-like properties of surface active ionic liquids (SAILs) have been used for preparation of microemulsions with high-temperature stability and temperature insensitivity. However, previously described methods present a limited possibility of developing IL-in-oil microemulsions with a wide range of thermal stability. With our previous work, we introduced a novel method of creating a huge number of IL-in-oil microemulsions (Rao, V. G.; Ghosh, S.; Ghatak, C.; Mandal, S.; Brahmachari, U.; Sarkar, N. J. Phys. Chem. B2012, 116, 2850-2855), composed of a SAIL as a surfactant, room-temperature ionic liquids as a polar phase, and benzene as a nonpolar phase. The use of benzene as a nonpolar solvent limits the application of the microemulsions to temperatures below 353 K. To overcome this limitation, we have synthesized N,N-dimethylethanolammonium 1,4-bis(2-ethylhexyl) sulfosuccinate (DAAOT), which was used as a surfactant. DAAOT in combination with isopropyl myristate (IPM, as an oil phase) and ILs (as a polar phase) produces a huge number of high-temperature stable IL-in-oil microemulsions. By far, this is the first report of a huge number of high-temperature stable IL-in-oil microemulsions. In particular, we demonstrate the wide range of thermal stability of [C6mim][TF2N]/DAAOT/IPM microemulsions by performing a phase behavior study, dynamic light scattering measurements, and (1)H NMR measurements and by using coumarin-480 (C-480) as a fluorescent probe molecule.

Engineering of a Stable Whole-Cell Biocatalyst Capable of (S)-Styrene Oxide Formation for Continuous Two-Liquid-Phase Applications

PubMed Central

Panke, Sven; de Lorenzo, Víctor; Kaiser, Arnë; Witholt, Bernard; Wubbolts, Marcel G.

1999-01-01

Recombinant strains of Pseudomonas putida KT2440 carrying genetic expression cassettes with xylene oxygenase- and styrene monooxygenase-encoding genes on their chromosomes could be induced in shaking-flask experiments to specific activities that rivaled those of multicopy-plasmid-based Escherichia coli recombinants. Such strains maintained the introduced styrene oxidation activity in continuous two-liquid-phase cultures for at least 100 generations, although at a lower level than in the shaking-flask experiments. The data suggest that placement of target genes on the chromosome might be a suitable route for the construction of segregationally stable and highly active whole-cell biocatalysts. PMID:10584030

Creation of energetic biothermite inks using ferritin liquid protein

PubMed Central

Slocik, Joseph M.; McKenzie, Ruel; Dennis, Patrick B.; Naik, Rajesh R.

2017-01-01

Energetic liquids function mainly as fuels due to low energy densities and slow combustion kinetics. Consequently, these properties can be significantly increased through the addition of metal nanomaterials such as aluminium. Unfortunately, nanoparticle additives are restricted to low mass fractions in liquids because of increased viscosities and severe particle agglomeration. Nanoscale protein ionic liquids represent multifunctional solvent systems that are well suited to overcoming low mass fractions of nanoparticles, producing stable nanoparticle dispersions and simultaneously offering a source of oxidizing agents for combustion of reactive nanomaterials. Here, we use iron oxide-loaded ferritin proteins to create a stable and highly energetic liquid composed of aluminium nanoparticles and ferritin proteins for printing and forming 3D shapes and structures. In total, this bioenergetic liquid exhibits increased energy output and performance, enhanced dispersion and oxidation stability, lower activation temperatures, and greater processability and functionality. PMID:28447665

Determination of quantitative retention-activity relationships between pharmacokinetic parameters and biological effectiveness fingerprints of Salvia miltiorrhiza constituents using biopartitioning and microemulsion high-performance liquid chromatography.

PubMed

Gao, Haoshi; Huang, Hongzhang; Zheng, Aini; Yu, Nuojun; Li, Ning

2017-11-01

In this study, we analyzed danshen (Salvia miltiorrhiza) constituents using biopartitioning and microemulsion high-performance liquid chromatography (MELC). The quantitative retention-activity relationships (QRARs) of the constituents were established to model their pharmacokinetic (PK) parameters and chromatographic retention data, and generate their biological effectiveness fingerprints. A high-performance liquid chromatography (HPLC) method was established to determine the abundance of the extracted danshen constituents, such as sodium danshensu, rosmarinic acid, salvianolic acid B, protocatechuic aldehyde, cryptotanshinone, and tanshinone IIA. And another HPLC protocol was established to determine the abundance of those constituents in rat plasma samples. An experimental model was built in Sprague Dawley (SD) rats, and calculated the corresponding PK parameterst with 3P97 software package. Thirty-five model drugs were selected to test the PK parameter prediction capacities of the various MELC systems and to optimize the chromatographic protocols. QRARs and generated PK fingerprints were established. The test included water/oil-soluble danshen constituents and the prediction capacity of the regression model was validated. The results showed that the model had good predictability. Copyright © 2017. Published by Elsevier B.V.

MAGNETIC LIQUID DEFORMABLE MIRRORS FOR ASTRONOMICAL APPLICATIONS: ACTIVE CORRECTION OF OPTICAL ABERRATIONS FROM LOWER-GRADE OPTICS AND SUPPORT SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borra, E. F., E-mail: borra@phy.ulaval.ca

2012-08-01

Deformable mirrors are increasingly used in astronomy. However, they still are limited in stroke for active correction of high-amplitude optical aberrations. Magnetic liquid deformable mirrors (MLDMs) are a new technology that has the advantages of high-amplitude deformations and low costs. In this paper, we demonstrate extremely high strokes and interactuator strokes achievable by MLDMs which can be used in astronomical instrumentation. In particular, we consider the use of such a mirror to suggest an interesting application for the next generation of large telescopes. We present a prototype 91 actuator deformable mirror made of a magnetic liquid (ferrofluid). This mirror usesmore » a technique that linearizes the response of such mirrors by superimposing a large and uniform magnetic field on the magnetic field produced by an array of small coils. We discuss experimental results that illustrate the performance of MLDMs. A most interesting application of MLDMs comes from the fact they could be used to correct the aberrations of large and lower optical quality primary mirrors held by simple support systems. We estimate basic parameters of the needed MLDMs, obtaining reasonable values.« less

Purification and sequencing of the active site tryptic peptide from penicillin-binding protein 1b of Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholas, R.A.; Suzuki, H.; Hirota, Y.

This paper reports the sequence of the active site peptide of penicillin-binding protein 1b from Escherichia coli. Purified penicillin-binding protein 1b was labeled with (/sup 14/C)penicillin G, digested with trypsin, and partially purified by gel filtration. Upon further purification by high-pressure liquid chromatography, two radioactive peaks were observed, and the major peak, representing over 75% of the applied radioactivity, was submitted to amino acid analysis and sequencing. The sequence Ser-Ile-Gly-Ser-Leu-Ala-Lys was obtained. The active site nucleophile was identified by digesting the purified peptide with aminopeptidase M and separating the radioactive products on high-pressure liquid chromatography. Amino acid analysis confirmed thatmore » the serine residue in the middle of the sequence was covalently bonded to the (/sup 14/C)penicilloyl moiety. A comparison of this sequence to active site sequences of other penicillin-binding proteins and beta-lactamases is presented.« less

Airway epithelial cell exposure to distinct e-cigarette liquid flavorings reveals toxicity thresholds and activation of CFTR by the chocolate flavoring 2,5-dimethypyrazine.

PubMed

Sherwood, Cara L; Boitano, Scott

2016-05-17

The potential for adverse respiratory effects following exposure to electronic (e-) cigarette liquid (e-liquid) flavorings remains largely unexplored. Given the multitude of flavor permutations on the market, identification of those flavor constituents that negatively impact the respiratory tract is a daunting task. In this study we examined the impact of common e-liquid flavoring chemicals on the airway epithelium, the cellular monolayer that provides the first line of defense against inhaled particulates, pathogens, and toxicants. We used the xCELLigence real-time cell analyzer (RTCA) as a primary high-capacity screening tool to assess cytotoxicity thresholds and physiological effects of common e-liquid flavoring chemicals on immortalized human bronchial epithelial cells (16HBE14o-). The RTCA was used secondarily to assess the capability of 16HBE14o- cells to respond to cellular signaling agonists following a 24 h exposure to select flavoring chemicals. Finally, we conducted biophysical measurements of well-differentiated primary mouse tracheal epithelial (MTE) cells with an Ussing chamber to measure the effects of e-cigarette flavoring constituents on barrier function and ion conductance. In our high-capacity screens five of the seven flavoring chemicals displayed changes in cellular impedance consistent with cell death at concentrations found in e-liquid. Vanillin and the chocolate flavoring 2,5-dimethylpyrazine caused alterations in cellular physiology indicative of a cellular signaling event. At subcytotoxic levels, 24 h exposure to 2,5-dimethylpyrazine compromised the ability of airway epithelial cells to respond to signaling agonists important in salt and water balance at the airway surface. Biophysical measurements of 2,5-dimethylpyrazine on primary MTE cells revealed alterations in ion conductance consistent with an efflux at the apical airway surface that was accompanied by a transient loss in transepithelial resistance. Mechanistic studies confirmed that the increases in ion conductance evoked by 2,5-dimethylpyrazine were largely attributed to a protein kinase A-dependent (PKA) activation of the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel. Data from our high-capacity screening assays demonstrates that individual e-cigarette liquid flavoring chemicals vary in their cytotoxicity profiles and that some constituents evoke a cellular physiological response on their own independent of cell death. The activation of CFTR by 2,5-dimethylpyrazine may have detrimental consequences for airway surface liquid homeostasis in individuals that use e-cigarettes habitually.

Long term storage of Pleurotus ostreatus and Trametes versicolor isolates using different cryopreservation techniques and its impact on laccase activity.

PubMed

Eichlerová, Ivana; Homolka, Ladislav; Tomšovský, Michal; Lisá, Ludmila

2015-12-01

The strain Pleurotus ostreatus Florida f6, its 45 basidiospore-derived isolates (both monokaryons and dikaryons prepared in our laboratory), Trametes versicolor strain CCBAS 614 and 22 other T. versicolor isolates obtained from the sporocarps collected in distant localities were successfully preserved for 12 y using perlite and straw cryopreservation protocols. All tested isolates survived a 12-year storage in liquid nitrogen (LN) and their laccase production and Poly B411 decolorization capacity was preserved. Also mycelium extension rate and the types of colony appearance of individual isolates remained unchanged. Different cryopreservation techniques were also tested for the short time (24 h) and the long time (6 m) storage of the culture liquid with extracellular laccase produced by T. versicolor strain CCBAS 614. The results showed that 10 % glycerol was the most suitable cryopreservant. The absence of the cryopreservant did not cause high loss of laccase activity in the samples; the presence of DMSO (5 or 10 %) in LN-stored samples caused mostly a decrease of laccase activity. For the preservation of laccase activity in the liquid culture the storage in the freezer at -80 °C is more convenient than the storage in liquid nitrogen. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Oxidized template-synthesized mesoporous carbon with pH-dependent adsorption activity: A promising adsorbent for removal of hydrophilic ionic liquid

NASA Astrophysics Data System (ADS)

Zhang, Ling; Cao, Wugang; Alvarez, Pedro J. J.; Qu, Xiaolei; Fu, Heyun; Zheng, Shourong; Xu, Zhaoyi; Zhu, Dongqiang

2018-05-01

Aiming to remove ionic liquid pollutants from water, an ordered mesoporous carbon CMK-3 (OMC) was prepared and modified by oxidation with nitric acid. A commercial microporous activated carbon adsorbent, Filtrasorb-300 (AC), was used as benchmark. Boehm titration showed that oxidized OMC had a substantially higher oxygen content than oxidized AC. Adsorption of the hydrophilic imidazolium-based ionic liquid 1-Butyl-3-methylimidazolium chloride ([Bmim]Cl) on OMC and AC was well-described by the Freundlich isotherm model. Surface oxidation markedly enhanced [Bmim]Cl adsorption by both OMC and AC. Nevertheless, [Bmim]Cl adsorption was much higher on oxidized OMC than on oxidized AC. Increasing pH had negligible influence on [Bmim]Cl adsorption on pristine OMC, but enhanced adsorption on oxidized OMC. Regeneration tests showed stable performance of oxidized OMC over five adsorption-desorption cycles. Thus, oxidized OMC can be a highly effective adsorbent for the removal of hydrophilic ionic liquids from water.

Heterogeneous conversion of CO2 into cyclic carbonates at ambient pressure catalyzed by ionothermal-derived meso-macroporous hierarchical poly(ionic liquid)s† †Electronic supplementary information (ESI) available: Experimental section, details of the IR, 13C NMR and XPS spectra, characterization (1H NMR, 13C NMR, 13C CP-MAS NMR, TG, XRD, SEM, elemental analysis), N2 adsorption–desorption isotherms, pore size distribution, recycling test of the catalyst, comparison of the literature catalytic activity of different heterogeneous catalysts. See DOI: 10.1039/c5sc02050f

PubMed Central

Wang, Xiaochen; Zhou, Yu; Guo, Zengjing; Chen, Guojian; Li, Jing; Shi, Yuming; Liu, Yangqing

2015-01-01

Meso-macroporous hierarchical poly(ionic liquid)s (MPILs) with extremely high ionic site densities and tunable pore structures were ionothermally synthesized through the free radical self-polymerization of our newly designed rigid bis-vinylimidazolium salt monomer. The synthesis avoided the use of any templates, gave a high yield (>99%) and allowed recycling of the IL solvent; thus it is facile, atom-efficient, environmentally friendly and sustainable. The synthesized MPILs possessed distinctive features of polycation matrices, abundant halogen anions, and large surface areas. They not only presented enhanced CO2 capture, but led to breakthroughs in the heterogeneous catalytic conversion of CO2 into cyclic carbonates: (1) unprecedented high activity at atmospheric pressure and low temperature; (2) good substrate compatibility, even being active towards the extremely inert aliphatic long carbon-chain alkyl epoxides. This result renders the first occasion of a metal–solvent–additive free recyclable heterogeneous cycloaddition of CO2 at such mild conditions. PMID:29861930

High performance supercapacitor from activated carbon derived from waste orange skin

NASA Astrophysics Data System (ADS)

Ahmed, Sultan; Hussain, S.; Ahmed, Ahsan; Rafat, M.

2018-05-01

Activated carbon due to its inherent properties such as large surface area and low cost is most frequently used electrode material for supercapacitor. Activated carbon has been previously derived from various biomass such as coconut shell, coffee bean etc. Herein, we report the synthesis of activated carbon from waste orange skin. The material was synthesized employing chemical activation method and the success of synthesis was confirmed by its physical and electrochemical properties. The physical properties of the as-prepared sample were studied using the techniques of XRD, SEM, Raman spectroscopy and N2 adsorption/desorption analysis while its electrochemical properties were studied in two-electrode assembly using liquid electrolyte (consisting of 1 M solution of LiTFSI dispersed in ionic liquid EMITFSI) and employing the techniques of cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge- discharge. The synthesized sample of activated carbon exhibits high specific capacitance of 115 F g-1 at 10 mV s-1. Also, the activated carbon electrode shows the retention of ˜75% in initial capacitance value for more than 2000 initial cycles, indicating the as-prepared activated carbon can be profitably used as electrode material for energy storage devices.

Source localization of brain activity using helium-free interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dammers, Jürgen, E-mail: J.Dammers@fz-juelich.de; Chocholacs, Harald; Eich, Eberhard

2014-05-26

To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-T{sub c}) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localizationmore » of neuromagnetic activity is indeed possible using high-T{sub c} SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-T{sub c} SQUID-based MEG systems.« less

175Hp contrarotating homopolar motor design report

NASA Astrophysics Data System (ADS)

Cannell, Michael J.; Drake, John L.; McConnell, Richard A.; Martino, William R.

1994-06-01

A normally conducting contrarotating homopolar motor has been designed and constructed. The reaction torque, in the outer rotor, from the inner rotor is utilized to produce true contrarotation. The machine utilizes liquid cooled conductors, high performance liquid metal current collectors, and ferrous conductors in the active region. The basic machine output is 175 hp at + or - 1,200 rpm with an input of 4 volts and 35,000 amps.

Purification and identification of corn peptides that facilitate alcohol metabolism by semi-preparative high-performance liquid chromatography and nano liquid chromatography with electrospray ionization tandem mass spectrometry.

PubMed

Ma, Zhi-Li; Hou, Tao; Shi, Wen; Liu, Wei-Wei; Ibrahim, Salam A; He, Hui

2016-11-01

In this study, peptides that facilitate alcohol metabolism were purified and identified from corn protein hydrolysates. The ultra-filtered fraction with a molecular weight < 3 kDa (F3) potential activity was separated into six fractions (F3-H1-F3-H6) by semi-preparative high-performance liquid chromatography. Among the resultant six fractions, F3-H4 and F3-H5 exhibited the highest ability to eliminate alcohol in vivo. A total of 16 peptides with strong signal values were identified from F3-H4 and F3-H5 fractions by nano liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Several identified peptides were then selected and synthesized to determine their potential to facilitate alcohol metabolism. We found that Leu-Leu and Pro-Phe were the key structure units in Gln-Leu-Leu-Pro-Phe responsible for this peptide's ability to facilitate alcohol metabolism. However, the role of Leu-Leu and Pro-Phe may be affected by peptide chain length and hydrophobic properties. Our results have thus provided some insight into the study of the structure-activity relationships of corn peptides. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR 265.314 - Special requirements for bulk and containerized liquids.

Code of Federal Regulations, 2011 CFR

2011-07-01

... carbon (e.g., aluminosilicates, clays, smectites, Fuller's earth, bentonite, calcium bentonite... charcoal/activated carbon); or (ii) High molecular weight synthetic polymers (e.g., polyethylene, high..., polyisobutylene, ground synthetic rubber, cross-linked allylstyrene and tertiary butyl copolymers). This does not...

Numerical modelling of ultrasonic waves in a bubbly Newtonian liquid using a high-order acoustic cavitation model.

PubMed

Lebon, G S Bruno; Tzanakis, I; Djambazov, G; Pericleous, K; Eskin, D G

2017-07-01

To address difficulties in treating large volumes of liquid metal with ultrasound, a fundamental study of acoustic cavitation in liquid aluminium, expressed in an experimentally validated numerical model, is presented in this paper. To improve the understanding of the cavitation process, a non-linear acoustic model is validated against reference water pressure measurements from acoustic waves produced by an immersed horn. A high-order method is used to discretize the wave equation in both space and time. These discretized equations are coupled to the Rayleigh-Plesset equation using two different time scales to couple the bubble and flow scales, resulting in a stable, fast, and reasonably accurate method for the prediction of acoustic pressures in cavitating liquids. This method is then applied to the context of treatment of liquid aluminium, where it predicts that the most intense cavitation activity is localised below the vibrating horn and estimates the acoustic decay below the sonotrode with reasonable qualitative agreement with experimental data. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Ultrasonic technique for monitoring of liquid density variations

NASA Astrophysics Data System (ADS)

Kazys, R.; Rekuviene, R.; Sliteris, R.; Mazeika, L.; Zukauskas, E.

2015-01-01

A novel ultrasonic measurement technique for density measurements of different liquids in extreme conditions has been developed. The proposed density measurement method is based on transformation of the acoustic impedance of the measured liquid. The higher accuracy of measurements is achieved by means of the λ/4 acoustic matching layer between the load and the ultrasonic waveguide transducer. Introduction of the matching layer enhances sensitivity of the measurement system. Sometimes, the density measurements must be performed in very complex conditions: high temperature (up to 200 °C), pressure (up to 10 MPa), and high chemical activity of the medium under measurement. In this case, the special geometry metal waveguides are proposed to use in order to protect the piezoelectric transducer surface from influence of a high temperature. The experimental set-up of technique was calibrated using the reference liquids with different densities: ethyl ether, ethyl alcohol, distilled water, and different concentration (20%, 40%, and 60%) sugar-water solutions. The uncertainty of measurements is less than 1%. The proposed measurement method was verified in real conditions by monitoring the density of a melted polypropylene during manufacturing process.

High energy supercapattery with an ionic liquid solution of LiClO4.

PubMed

Yu, Linpo; Chen, George Z

2016-08-15

A supercapattery combining an ideally polarized capacitor-like electrode and a battery-like electrode is demonstrated theoretically and practically using an ionic liquid electrolyte containing 1-butyl-1-methylpyrrolidinium tri(pentafluoroethyl)trifluorophosphate (BMPyrrFAP), gamma-butyrolactone (γ-GBL) and LiClO4. The electrochemical deposition and dissolution of lithium metal on a platinum and glass carbon electrode were investigated in this ionic liquid solution. The CVs showed that the fresh electrochemically deposited lithium metal was stable in the electrolyte, which encouraged the investigation of this ionic liquid solution in a supercapattery with a lithium battery negative electrode. The active material counted specific energy of the supercapattery based on a lithium negative electrode and an activated carbon (Act-C) positive electrode could reach 230 W h kg(-1) under a galvanostatic charge-discharge current density of 1 mA cm(-2). The positive electrode material (Act-C) was also investigated by CV, AC impedance, SEM and BET. The non-uniform particle size and micropores dominated porous structure of the Act-C enabled its electric double layer capacitor (EDLC) behavior in the ionic liquid solution. The measured specific capacitance of the Act-C in this ionic liquid solution is higher than the same Act-C in aqueous solution, which indicates the Act-C can also perform well in the ionic liquid electrolyte.

Peptide profiling of Internet-obtained Cerebrolysin using high performance liquid chromatography - electrospray ionization ion trap and ultra high performance liquid chromatography - ion mobility - quadrupole time of flight mass spectrometry.

PubMed

Gevaert, Bert; D'Hondt, Matthias; Bracke, Nathalie; Yao, Han; Wynendaele, Evelien; Vissers, Johannes Petrus Cornelis; De Cecco, Martin; Claereboudt, Jan; De Spiegeleer, Bart

2015-09-01

Cerebrolysin, a parenteral peptide preparation produced by controlled digestion of porcine brain proteins, is an approved nootropic medicine in some countries. However, it is also easily and globally available on the Internet. Nevertheless, until now, its exact chemical composition was unknown. Using high performance liquid chromatography (HPLC) coupled to ion trap and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-ion mobility-time-of-flight mass spectrometry (Q-IM-TOF MS), combined with UniProt pig protein database search and PEAKS de novo sequencing, we identified 638 unique peptides in an Internet-obtained Cerebrolysin sample. The main components in this sample originate from tubulin alpha- and beta-chain, actin, and myelin basic protein. No fragments of known neurotrophic factors like glial cell-derived neurotrophic factor (GDNF), neurotrophin nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF) were found, suggesting that the activities reported in the literature are likely the result of new, hitherto unknown cryptic peptides with nootropic properties. Copyright © 2015 John Wiley & Sons, Ltd.

An examination of the prescription and dispensing of medicines by Western herbal therapists: a national survey in Australia.

PubMed

Casey, M G; Adams, J; Sibbritt, D

2007-03-01

To describe the patterns of prescription and dispensing of herbal medicines employed by Western herbal practitioners in Australia. A national postal survey sent to all full members of the National Herbalist Association of Australia (NHAA). Nationwide clinics of professional herbal practitioners in Australia. Measures of medicinal use were collected including aspects of prescription, formulation, dispensing and preparation forms of medicines used. The practitioners were asked if they dispensed their own medicines, about the form of herbal preparations used, aspects of formulation and dosages. The predominant prescription by most Western herbal practitioners in Australia is individualised herbal formulae rather than the use of single herbs. Traditional preparations of herbals such as teas and powders are used but liquid herbal extracts are most commonly dispensed. These liquid medicines are in the form of highly concentrated fluid extracts in ratios of 1:1 or 1:2, herb material to liquid. Pre-formulated tablets or capsules made by herbal manufacturers are being incorporated into modern practice but most prescriptions are individualised liquid formulae prepared and dispensed, from the clinic dispensary, after patient consultation. In addition to internal prescriptions, topical creams, pessaries, douches, gargles, eyebaths and poultices or washes are still incorporated into treatments. Although there is variation in used dosage ranges, the predominant system is that of pharmacologically active doses of highly concentrated fluid extracts. The professional prescription of Western herbal medicines is different to commercial usage. As opposed to pre-formulated tablets, or use of single herbals, the vast majority of Western herbalists in Australia construct individualised herbal formulations for their patients after consultation. The preferred form of administration of these prescriptions is as highly concentrated liquid herbal extracts in pharmacologically active doses.

Wavefront control with a spatial light modulator containing dual-frequency liquid crystal

NASA Astrophysics Data System (ADS)

Gu, Dong-Feng; Winker, Bruce; Wen, Bing; Taber, Don; Brackley, Andrew; Wirth, Allan; Albanese, Marc; Landers, Frank

2004-10-01

A versatile, scalable wavefront control approach based upon proven liquid crystal (LC) spatial light modulator (SLM) technology was extended for potential use in high-energy near-infrared laser applications. The reflective LC SLM module demonstrated has a two-inch diameter active aperture with 812 pixels. Using an ultra-low absorption transparent conductor in the LC SLM, a high laser damage threshold was demonstrated. Novel dual frequency liquid crystal materials and addressing schemes were implemented to achieve fast switching speed (<1ms at 1.31 microns). Combining this LCSLM with a novel wavefront sensing method, a closed loop wavefront controller is being demonstrated. Compared to conventional deformable mirrors, this non-mechanical wavefront control approach offers substantial improvements in speed (bandwidth), resolution, power consumption and system weight/volume.

Oxalic Acid from Lentinula edodes Culture Filtrate: Antimicrobial Activity on Phytopathogenic Bacteria and Qualitative and Quantitative Analyses

PubMed Central

Kwak, A-Min; Lee, In-Kyoung; Lee, Sang-Yeop

2016-01-01

The culture filtrate of Lentinula edodes shows potent antimicrobial activity against the plant pathogenic bacteria Ralstonia solanacearum. Bioassay-guided fractionation was conducted using Diaion HP-20 column chromatography, and the insoluble active compound was not adsorbed on the resin. Further fractionation by high-performance liquid chromatography (HPLC) suggested that the active compounds were organic acids. Nine organic acids were detected in the culture filtrate of L. edodes; oxalic acid was the major component and exhibited antibacterial activity against nine different phytopathogenic bacteria. Quantitative analysis by HPLC revealed that the content of oxalic acid was higher in the water extract from spent mushroom substrate than in liquid culture. This suggests that the water extract of spent L. edodes substrate is an eco-friendly control agent for plant diseases. PMID:28154495

Chemical and thermal stability of N-heterocyclic ionic liquids in catalytic C-H activation reactions.

PubMed

Chen, Guanyi; Kang, Shujuan; Ma, Qisheng; Chen, Weiqun; Tang, Yongchun

2014-11-01

(1)H-NMR spectrum analyses are applied to study the chemical and thermal stability of selected N-heterocyclic ionic liquids within the reaction system that can highly efficiently activate a C-H bond of methane and convert it into the C-O bond in methanol. Our results indicate that under such reaction conditions involving using a powerful Pt-based catalyst and strong acidic solvent, the aromatic ring of an imidazolium cation becomes unstable generating an ammonium ion (NH(4)(+)). Our results also suggest that the instability of the imidazolium ring is more chemically (participation in reactions) than thermally based. Modifications of the aromatic ring structure such as pyrazolium and triazolium cations can increase the chemical/thermal stability of ionic liquids under these reaction conditions. Copyright © 2014 John Wiley & Sons, Ltd.

High-temperature phase relations and thermodynamics in the iron-lead-sulfur system

NASA Astrophysics Data System (ADS)

Eric, R. Hurman; Ozok, Hakan

1994-01-01

The PbS activities in FeS-PbS liquid mattes were obtained at 1100 °C and 1200 °C by the dew-point method. Negative deviations were observed, and the liquid-matte solutions were modeled by the Krupkowski formalism. The liquid boundaries of the FeS-PbS phase diagram were derived from the model equations yielding a eutectic temperature of 842 °C at X Pbs = 0.46. A phase diagram of the pseudobinary FeS-PbS was also verified experimentally by quenching samples equilibrated in evacuated and sealed silica capsules. No terminal solid solution ranges could be found. Within the Fe-Pb-S ternary system, the boundaries of the immiscibility region together with the tie-line distributions were established at 1200 °C. Activities of Pb were measured by the dew-point technique along the metal-rich boundary of the miscibility gap. Activities of Fe, Pb, and S, along the miscibility gap were also calculated by utilizing the bounding binary thermodynamics, phase equilibria, and tie-lines.

Rational Design and Facile Synthesis of Boranophosphate Ionic Liquids as Hypergolic Rocket Fuels.

PubMed

Liu, Tianlin; Qi, Xiujuan; Wang, Binshen; Jin, Yunhe; Yan, Chao; Wang, Yi; Zhang, Qinghua

2018-05-14

The design and synthesis of new hypergolic ionic liquids (HILs) as replacements for toxic hydrazine derivatives have been the focus of current academic research in the field of liquid bipropellant fuels. In most cases, however, the requirements of excellent ignition performances, good hydrolytic stabilities, and low synthetic costs are often contradictory, which makes the development of high-performance HILs an enormous challenge. Here, we show how a fuel-rich boranophosphate ion was rationally designed and used to synthesize a series of high-performance HILs with excellent comprehensive properties. In the design strategy, we introduced the {BH 3 } moiety into the boranophosphate ion for improving the self-ignition property, whereas the complexation of boron and phosphite was used to improve the hydrolytic activity of the borohydride species. As a result, these boranophosphate HILs exhibited wide liquid operating ranges (>220 °C), high densities (1.00-1.10 g cm -3 ), good hydrolytic stabilities, and short ignition delay times (2.3-9.7 milliseconds) with white fuming nitric acid (WFNA) as the oxidizer. More importantly, these boranophosphate HILs could be readily prepared in high yields from commercial phosphite esters, avoiding complex and time-consuming synthetic routes. This work offers an effective strategy of designing boranophosphate HILs towards safer and greener hypergolic fuels for liquid bipropellant applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Performance Liquid Chromatography-Diode Array Detector Method for the Simultaneous Determination of Five Compounds in the Pulp and Seed of Sea Buckthorn

PubMed Central

Zhao, Lu; Wen, E; Upur, Halmuart; Tian, Shuge

2017-01-01

Context: Sea buckthorn (Hippophae rhamnoides L.) as a traditional Chinese medicinal plant has various uses in Xinjiang. Objective: A reversed-phase rapid-resolution liquid-chromatography method with diode array detector was developed for simultaneous determination of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the pulp and seed of sea buckthorn, a widely used traditional Chinese medicine for promoting metabolism and treating scurvy and other diseases. Settings and design: Compounds were separated on an Agilent ZORBAX SB-C18 column (4.6 mm × 250 mm, 5 μm; USA) with gradient elution using methanol and 0.4% phosphoric acid (v/v) at 1.0 mL/min. Detection wavelength was set at 280 nm. Materials and Methods: The fruits of wild sea buckthorn were collected from Wushi County in Aksu, Xinjiang Province. Statistical performances: The RSD of precision test of the five compounds were in the range of 0.60-2.22%, and the average recoveries ranged from 97.36% to 101.19%. Good linearity between specific chromatographic peak and component qualities were observed in the investigated ranges for all the analytes (R2 > 0.9997). Results: The proposed method was successfully applied to determine the levels of five active components in sea buckthorn samples from Aksu in Xinjiang. Conclusions: The proposed method is simple, fast, sensitive, accurate, and suitable for quantitative assessment of the pulp and seed of sea buckthorn. SUMMARY Quantitative analysis method of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the extract of sea buckthorn pulp and seed is developed by high-performance liquid chromatography (HPLC) diode array detection.This method is simple and accurate; has strong specificity, good precision, and high recovery rate; and provides a reliable basis for further development of the substances in the pulp and seed of sea buckthorn.The method is widely used for content determination of active ingredients or physiologically active components in traditional Chinese medicine and its preparation Abbreviation used: PR: protocatechuic acid, RU: rutin, QU: quercetin, KA: kaempferol, IS: isorhamnetin, HPLC: high-performance liquid chromatography, HPLC-DAD: high performance liquid chromatographydiode array detector, LOD: linearity and limit of detection, LOQ: limit of quantitation, RSD: relative standard deviation PMID:28216897

Phenolic acids and antioxidant activity of distillers dried grains with solubles (DDGS) as compared with corn

USDA-ARS?s Scientific Manuscript database

Sample sets of ground corn and the corresponding distillers dried grains with solubles (DDGS) were collected from three commercial plants in Iowa. Phenolic acids were analyzed by high performance liquid chromatography coupled with diode array and/or mass spectrometry. The antioxidant activity was ...

Developing analytical approaches to explore the connectionbetween endocrine-active pharmaceuticals in waterto effects in fish

EPA Science Inventory

The emphasis of this research project was to develop, and optimize, a solid-phase extraction (SPE) method and high performance liquid chromatography-electrospray ionization- mass spectrometry (LC-MS/MS) method, such that a linkage between the detection of endocrine active pharma...

Numerical and experimental study of liquid breakup process in solid rocket motor nozzle

NASA Astrophysics Data System (ADS)

Yen, Yi-Hsin

Rocket propulsion is an important travel method for space exploration and national defense, rockets needs to be able to withstand wide range of operation environment and also stable and precise enough to carry sophisticated payload into orbit, those engineering requirement makes rocket becomes one of the state of the art industry. The rocket family have been classified into two major group of liquid and solid rocket based on the fuel phase of liquid or solid state. The solid rocket has the advantages of simple working mechanism, less maintenance and preparing procedure and higher storage safety, those characters of solid rocket make it becomes popular in aerospace industry. Aluminum based propellant is widely used in solid rocket motor (SRM) industry due to its avalibility, combusion performance and economical fuel option, however after aluminum react with oxidant of amonimum perchrate (AP), it will generate liquid phase alumina (Al2O3) as product in high temperature (2,700˜3,000 K) combustion chamber enviornment. The liquid phase alumina particles aggromorate inside combustion chamber into larger particle which becomes major erosion calprit on inner nozzle wall while alumina aggromorates impinge on the nozzle wall surface. The erosion mechanism result nozzle throat material removal, increase the performance optimized throat diameter and reduce nozzle exit to throat area ratio which leads to the reduction of exhaust gas velocity, Mach number and lower the propulsion thrust force. The approach to avoid particle erosion phenomenon taking place in SRM's nozzle is to reduce the alumina particle size inside combustion chamber which could be done by further breakup of the alumina droplet size in SRM's combustion chamber. The study of liquid breakup mechanism is an important means to smaller combustion chamber alumina droplet size and mitigate the erosion tack place on rocket nozzle region. In this study, a straight two phase air-water flow channel experiment is set up for liquid breakup phenomenon observation. The liquid water material in this experiment will play a comparison role as liquid alumina in high temerature enviornment. The method proposed to control the liquid breakup size of liquid droplet is done by the means of changing the liquid properties of surface tension. The surface tenion of liquid plays an inportant role of providing major liquid droplet bounding pressure or Laplace pressure. By reduceing surface tension of liquid leads to lower Laplace pressure of droplet and result in less droplet dynamic stability which could be breakup under external pressure difference. The reduction of surface tension of liquid aluminum could be achieved by adding magnisium and strontium, it is reported that the surface tension reeducation level could reach 10%˜15% when those additive mension above are adding to aluminum. This study of liquid breakup mechanism include two major part, first part is straight two-phase channel experiment and simulation comparison which provide a validation work of CFD simulation performance when compare to experiment. Second part is single droplet breakup experiment, in this experiment the relation of surface tension and liquid breakup behavior is carefully studied. The straight two-phase flow channel experiment setting will enable to us to study the liquid breakup process in macro scale. The quantification method is achieved by analyzing high-speed camera image by MatLab image process code develop in UW-Milwaukee wind tunnel lab which extract data in images and provide information including liquid droplet count and size distribution, wave frequency and time averaging two-phase free boundary. It was found that liquid breakup mechanism proportional to gas-droplet velocity difference square, gas density and liquid droplet size and inverse proportional to liquid surface tension. The single droplet experiment part is provide a close up view of liquid breakup and prove the reduced surface tension will enhance liquid breakup activity. In this study, we could observe the evidence of enhance liquid breakup activity by the reduced surface tension of liquid. Therefor the approach of reducing surface tension of Solid Rocket Motor (SRM) fuel reacting product is a high potential solution to SRM nozzle erosion.

Non-allowed Pharmacologically Active Substances in Physical and Sexual Performance Enhancing Products

PubMed Central

Pellegrini, Manuela; Rotolo, Maria Concetta; Busardò, Francesco Paolo; Pacifici, Roberta; Pichini, Simona

2017-01-01

Background: Recently, a large amount of physical and sexual performance enhancing products have started to be freely sold mainly on internet web sites as dietary supplements. However, there a high suspicion that pharmacologically active substance, prohibited in these products, can be present to provide the expected effect. Methods: A simple and rapid systematic toxicological analysis by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry has been applied after a liquid-liquid extraction at acidic, neutral and alkaline pH with chloroform-isopropanol (9:1 v/v). The assays were validated in the range from 10 mg to 250 mg/g products showing a good linearity for the calibration curves (r2 ≥0.99). Mean extraction recoveries of analytes from different products were always higher than 90% and intra-assay and inter-assay precision and accuracy were always better than 15%. Results: The developed method was applied to the analysis of products with a high percentage of sales in websites and smart and sexy shops. In twelve of eighty supplements, anabolic steroids, anti-estrogenic drugs, psychoactive substances and sildenafil and analogs were identified and quantified. Conclusion: Eventual health hazards caused by the hidden presence of pharmacologically active substances in physical and sexual performance enhancing products are reported. PMID:27799033

Self-assembly and enhanced photocatalytic properties of BiOI hollow microspheres via a reactable ionic liquid.

PubMed

Xia, Jiexiang; Yin, Sheng; Li, Huaming; Xu, Hui; Yan, Yongsheng; Zhang, Qi

2011-02-01

BiOI uniform flowerlike hollow microspheres with a hole in its surface structures have been successfully synthesized through an EG-assisted solvothermal process in the presence of ionic liquid 1-butyl-3-methylimidazolium iodine ([Bmim]I). The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), nitrogen sorption, and diffuse reflectance spectroscopy (DRS). A possible formation mechanism for the growth of hollow microspheres was discussed. During the reactive process, ionic liquid not only acted as solvents and templates but also as an I source for the fabrication of BiOI hollow microspheres and was vital for the structure of hollow microspheres. Additionally, we evaluated the photocatalytic activities of BiOI on the degradation of methyl orange (MO) under visible light irradiation and found that as-prepared BiOI hollow microspheres exhibited higher photocatalytic activity than BiOI nanoplates and TiO(2) (Degussa, P25) did. On the basis of such analysis, it can be assumed that the enhanced photocatalytic activities of BiOI hollow microspheres could be ascribed to its energy band structure, high BET surface area, high surface-to-volume ratios, and light absorbance.

Liquid-like cationic sub-lattice in copper selenide clusters

NASA Astrophysics Data System (ADS)

White, Sarah L.; Banerjee, Progna; Jain, Prashant K.

2017-02-01

Super-ionic solids, which exhibit ion mobilities as high as those in liquids or molten salts, have been employed as solid-state electrolytes in batteries, improved thermoelectrics and fast-ion conductors in super-capacitors and fuel cells. Fast-ion transport in many of these solids is supported by a disordered, `liquid-like' sub-lattice of cations mobile within a rigid anionic sub-lattice, often achieved at high temperatures or pressures via a phase transition. Here we show that ultrasmall clusters of copper selenide exhibit a disordered cationic sub-lattice under ambient conditions unlike larger nanocrystals, where Cu+ ions and vacancies form an ordered super-structure similar to the bulk solid. The clusters exhibit an unusual cationic sub-lattice arrangement wherein octahedral sites, which serve as bridges for cation migration, are stabilized by compressive strain. The room-temperature liquid-like nature of the Cu+ sub-lattice combined with the actively tunable plasmonic properties of the Cu2Se clusters make them suitable as fast electro-optic switches.

A Class of Organopolysulfides As Liquid Cathode Materials for High-Energy-Density Lithium Batteries.

PubMed

Bhargav, Amruth; Bell, Michaela Elaine; Karty, Jonathan; Cui, Yi; Fu, Yongzhu

2018-06-27

Sulfur-based cathodes are promising to enable high-energy-density lithium-sulfur batteries; however, elemental sulfur as active material faces several challenges, including undesirable volume change (∼80%) when completely reduced and high dependence on liquid electrolyte wherein an electrolyte/sulfur ratio >10 μL mg -1 is required for high material utilization. These limit the attainable energy densities of these batteries. Herein, we introduce a new class of phenyl polysulfides C 6 H 5 S x C 6 H 5 (4 ≤ x ≤ 6) as liquid cathode materials synthesized in a facile and scalable route to mitigate these setbacks. These polysulfides possess sufficiently high theoretical specific capacities, specific energies, and energy densities. Spectroscopic techniques verify their chemical composition and computation shows that the volume change when reduced is about 37%. Lithium half-cell testing shows that phenyl hexasulfide (C 6 H 5 S 6 C 6 H 5 ) can provide a specific capacity of 650 mAh g -1 and capacity retention of 80% through 500 cycles at 1 C rate along with superlative performance up to 10 C. Furthermore, 1302 Wh kg -1 and 1720 Wh L -1 are achievable at a low electrolyte/active material ratio, i.e., 3 μL mg -1 . This work adds new members to the cathode family for Li-S batteries, reduces the gap between the theoretical and practical energy densities of batteries, and provides a new direction for the development of alternative high-capacity cathode materials.

Topological sound in active-liquid metamaterials

NASA Astrophysics Data System (ADS)

Souslov, Anton

Active liquids can flow spontaneously even in the absence of an external drive. Recently, such liquids have been experimentally realized using molecular, colloidal, or macroscopic self-propelled constituents. Using active liquids as a building material, we lay out design principles for artificial structures termed topological active metamaterials. Such metamaterials break time-reversal symmetry and can be designed using periodic lattices composed of annular channels filled with a spontaneously flowing active liquid. We show that these active metamaterials support topologically protected sound modes that propagate unidirectionally (without backscattering) along either sample edges or domain walls, and despite overdamped particle dynamics. Our work illustrates how parity-symmetry breaking in metamaterial structure combined with microscopic irreversibility of active matter leads to novel functionalities that cannot be achieved using only passive materials.

Ionic Liquids and New Proton Exchange Membranes for Fuel Cells

NASA Technical Reports Server (NTRS)

Belieres, Jean-Philippe

2004-01-01

There is currently a great surge of activity in fuel cell research as laboratories across the world seek to take advantage of the high energy capacity provided by &el cells relative to those of other portable electrochemical power systems. Much of this activity is aimed at high temperature fie1 cells, and a vital component of such &el cells must be the availability of a high temperature stable proton-permeable membrane. NASA Glenn Research Center is greatly involved in developing this technology. Other approaches to the high temperature fuel cell involve the use of single- component or almost-single-component electrolytes that provide a path for protons through the cell. A heavily researched case is the phosphoric acid fuel cell, in which the electrolyte is almost pure phosphoric acid and the cathode reaction produces water directly. The phosphoric acid fie1 cell delivers an open circuit voltage of 0.9 V falling to about 0.7 V under operating conditions at 170 C. The proton transport mechanism is mainly vehicular in character according to the viscosity/conductance relation. Here we describe some Proton Transfer Ionic Liquids (PTILs) with low vapor pressure and high temperature stability that have conductivities of unprecedented magnitude for non-aqueous systems. The first requirement of an ionic liquid is that, contrary to experience with most liquids consisting of ions, it must have a melting point that is not much above room temperature. The limit commonly suggested is 100 C. PTILs constitute an interesting class of non-corrosive proton-exchange electrolyte, which can serve well in high temperature (T = 100 - 250 C) fuel cell applications. We will present cell performance data showing that the open circuit voltage output, and the performance of a simple H2(g)Pt/PTIL/Pt/O2(g) fuel cell may be superior to those of the equivalent phosphoric acid electrolyte fuel cell both at ambient temperature and temperatures up to and above 200 C. My work at NASA Glenn Research Center during this summer is to develop and characterize proton exchange membranes doped with ionic liquids. The main techniques used to characterize these materials are: Impedance Spectroscopy, NMR, DSC, TGA, DMA, IR, and SEM ...

SABRE: Dark matter annual modulation detection in the northern and southern hemispheres

NASA Astrophysics Data System (ADS)

Tomei, C.

2017-02-01

SABRE (Sodium-iodide with Active Background REjection) is a new NaI(Tl) experiment designed to search for galactic Dark Matter through the annual modulation signature. SABRE will consist of highly pure NaI(Tl) crystals operated in an active liquid scintillator veto. The SABRE experiment will follow a two-phase approach. In the first phase, one high-purity NaI(Tl) crystal will be operated at LNGS in an active liquid scintillator veto with the goal of demonstrating backgrounds low enough for a sensitive test of the DAMA/LIBRA result. An unprecedented radio-purity for both the NaI powder and the crystal growth will be needed to achieve this goal. The second phase will consist in building two high-purity NaI(Tl) detector arrays, with a total mass of about 50 kg each, located at LNGS and in the Stawell Gold Mine in Australia. The operation of twin full-scale experiments in both the northern and the southern hemispheres will strengthen the reliability of the result against any possible seasonal systematic effect.

Nuclear and analytical methods for investigation of high quality wines

NASA Astrophysics Data System (ADS)

Tonev, D.; Geleva, E.; Grigorov, T.; Goutev, N.; Protohristov, H.; Stoyanov, Ch; Bashev, V.; Tringovska, I.; Kostova, D.

2018-05-01

Nuclear and analytical methods can help to determine the year of production – vintage and the geographical provenance of high quality wines. A complex analytical investigation of Melnik fine wines from “Artarkata” vineyards, Vinogradi village near Melnik in Southwest Bulgaria using different methods and equipment were performed. Nuclear methods, based on measured gamma-ray activity of 137Cs and specific activity of 3H can be used to determine the year of wine production. The specific activity of 137Cs was measured in wines from different vintages using Low-Background High-Resolution Gamma-Spectrometry. Tritium measurements in wine samples were carried out by using a low level liquid scintillation counting in a Packard Tri-Carb 2770 TR/SL liquid scintillation analyzer. The identification of the origin of wines using their chemical fingerprints is of great interest for wine consumers and producers. Determination of 16 chemical elements in samples from soil, wine stems, wine leaves and fine wine from the type Shiroka Melnishka, which are grown in typical Melnik vineyard was made, using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES).

High Performance Liquid Chromatography-mass Spectrometry Analysis of High Antioxidant Australian Fruits with Antiproliferative Activity Against Cancer Cells.

PubMed

Sirdaarta, Joseph; Maen, Anton; Rayan, Paran; Matthews, Ben; Cock, Ian Edwin

2016-05-01

High antioxidant capacities have been linked to the treatment and prevention of several cancers. Recent reports have identified several native Australian fruits with high antioxidant capacities. Despite this, several of these species are yet to be tested for anticancer activity. Solvent extracts prepared from high antioxidant native Australian fruits were analyzed for antioxidant capacity by the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium free radical scavenging assay. Antiproliferative activities against CaCo2 and HeLa cancer cells were determined by a multicellular tumor spheroid-based cell proliferation assay. Toxicity was determined by Artemia franciscana bioassay. Methanolic extracts of all plant species displayed high antioxidant contents (equivalent to approximately 7-16 mg of vitamin C per gram of fruit extracted). Most aqueous extracts also contained relatively high antioxidant capacities. In contrast, the ethyl acetate, chloroform, and hexane extracts of most species (except lemon aspen and bush tomato) had lower antioxidant contents (below 1.5 mg of vitamin C equivalents per gram of plant material extracted). The antioxidant contents correlated with the ability of the extracts to inhibit proliferation of CaCo2 and HeLa cancer cell lines. The high antioxidant methanolic extracts of all species were potent inhibitors of cell proliferation. The methanolic lemon aspen extract was particularly effective, with IC50 values of 480 and 769 μg/mL against HeLa and CaCo2 cells, respectively. In contrast, the lower antioxidant ethyl acetate and hexane extracts (except the lemon aspen ethyl acetate extract) generally did not inhibit cancer cell proliferation or inhibited to only a minor degree. Indeed, most of the ethyl acetate and hexane extracts induced potent cell proliferation. The native tamarind ethyl acetate extract displayed low-moderate toxicity in the A. franciscana bioassay (LC50 values below 1000 μg/mL). All other extracts were nontoxic. A total of 145 unique mass signals were detected in the lemon aspen methanolic and aqueous extracts by nonbiased high-performance liquid chromatography-mass spectrometry analysis. Of these, 20 compounds were identified as being of particular interest due to their reported antioxidant and/or anticancer activities. The lack of toxicity and antiproliferative activity of the high antioxidant plant extracts against HeLa and CaCo2 cancer cell lines indicates their potential in the treatment and prevention of some cancers. Australian fruit extracts with high antioxidant contents were potent inhibitors of CaCo2 and HeLa carcinoma cell proliferationMethanolic lemon aspen extract was particularly potent, with IC50 values of 480 μg/mL (HeLa) and 769 μg/mL (CaCo2)High-performance liquid chromatography-mass spectrometry-quadrupole time-of-flight analysis highlighted and putatively identified 20 compounds in the antiproliferative lemon aspen extractsIn contrast, lower antioxidant content extracts stimulated carcinoma cell proliferationAll extracts with antiproliferative activity were nontoxic in the Artemia nauplii assay. Abbreviations used: DPPH: di (phenyl)- (2,4,6-trinitrophenyl) iminoazanium, HPLC: High-performance liquid chromatography, IC50: The concentration required to inhibit by 50%, LC50: The concentration required to achieve 50% mortality, MS: Mass spectrometry.

Confused ionic liquid ions--a "liquification" and dosage strategy for pharmaceutically active salts.

PubMed

Bica, Katharina; Rogers, Robin D

2010-02-28

We present a strategy to expand the liquid and compositional ranges of ionic liquids, specifically pharmaceutically active ionic liquids, by simple mixing with a solid acid or base to form oligomeric ions.

Aerosol partitioning between the interstitial and the condensed phase in mixed-phase clouds

NASA Astrophysics Data System (ADS)

Verheggen, Bart; Cozic, Julie; Weingartner, Ernest; Bower, Keith; Mertes, Stephan; Connolly, Paul; Gallagher, Martin; Flynn, Michael; Choularton, Tom; Baltensperger, Urs

2007-12-01

The partitioning of aerosol particles between the cloud and the interstitial phase (i.e., unactivated aerosol) has been investigated during several Cloud and Aerosol Characterization Experiments (CLACE-3, CLACE-3? and CLACE-4) conducted in winter and summer 2004 and winter 2005 at the high alpine research station Jungfraujoch (3580 m altitude, Switzerland). Ambient air was sampled using different inlets in order to determine the activated fraction of aerosol particles, FN, defined as the fraction of the total aerosol number concentration (with particle diameter dp > 100 nm) that has been incorporated into cloud particles. The liquid and ice water content of mixed-phase clouds were characterized by analyzing multiple cloud probes. The dependence of the activated fraction on several environmental factors is discussed on the basis of more than 900 h of in-cloud observations and parameterizations for key variables are given. FN is found to increase with increasing liquid water content and to decrease with increasing particle number concentration in liquid clouds. FN also decreases with increasing cloud ice mass fraction and with decreasing temperature from 0 to -25°C. The Wegener-Bergeron-Findeisen process probably contributed to this trend, since the presence of ice crystals causes liquid droplets to evaporate, thus releasing the formerly activated particles back into the interstitial phase. Ice nucleation could also have prevented additional cloud condensation nuclei from activating. The observed activation behavior has significant implications for our understanding of the indirect effect of aerosols on climate.

Ionic liquid-assisted photochemical synthesis of ZnO/Ag2O heterostructures with enhanced visible light photocatalytic activity

NASA Astrophysics Data System (ADS)

Zhao, Shuo; Zhang, Yiwei; Zhou, Yuming; Zhang, Chao; Fang, Jiasheng; Sheng, Xiaoli

2017-07-01

ZnO/Ag2O heterostructures have been successfully fabricated using ionic liquids (ILs) as templates by a simple photochemical route. The influence of the type of ionic liquid and synthetic method on the morphology of ZnO, as well as the photocatalytic activity for the degradation of Rhodamine B (RhB), tetracycline (TC) and ciprofloxacin (CIP) under ultraviolet and visible light irradiation was studied. The samples were characterized by XRD, SEM, TEM, PL and UV-vis DRS. The results established that the type of ionic liquid and synthetic method played an important role in the growth of ZnO nanoparticles. And as-fabricated ZnO/Ag2O materials exhibited self-assembled flower-like architecture whose size was about 3 μm. Moreover, as-prepared ZnO/Ag2O exhibited the enhanced photocatalytic activity than ZnO sample, which may be due to the special structure, heterojunction, enhanced adsorption capability of dye, the improved separation rate of photogenerated electron-hole pairs. According to the results of radical trapping experiments, it can be found that •OH and h+ were the main active species for the photocatalytic degradation of RhB. It is valuable to develop this facile route preparing the highly dispersive flower-like ZnO/Ag2O materials, which can be beneficial for environmental protection.

Updated Liquid Secondary Waste Grout Formulation and Preliminary Waste Form Qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saslow, Sarah A.; Um, Wooyong; Russell, Renee L.

This report describes the results from liquid secondary waste grout (LSWG) formulation and cementitious waste form qualification tests performed by Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions, LLC (WRPS). New formulations for preparing a cementitious waste form from a high-sulfate liquid secondary waste stream simulant, developed for Effluent Management Facility (EMF) process condensates merged with low activity waste (LAW) caustic scrubber, and the release of key constituents (e.g. 99Tc and 129I) from these monoliths were evaluated. This work supports a technology development program to address the technology needs for Hanford Site Effluent Treatment Facility (ETF) liquid secondarymore » waste (LSW) solidification and supports future Direct Feed Low-Activity Waste (DFLAW) operations. High-priority activities included simulant development, LSWG formulation, and waste form qualification. The work contained within this report relates to waste form development and testing and does not directly support the 2017 integrated disposal facility (IDF) performance assessment (PA). However, this work contains valuable information for use in PA maintenance past FY17, and for future waste form development efforts. The provided data should be used by (i) cementitious waste form scientists to further understanding of cementitious dissolution behavior, (ii) IDF PA modelers who use quantified constituent leachability, effective diffusivity, and partitioning coefficients to advance PA modeling efforts, and (iii) the U.S. Department of Energy (DOE) contractors and decision makers as they assess the IDF PA program. The results obtained help fill existing data gaps, support final selection of a LSWG waste form, and improve the technical defensibility of long-term waste form performance estimates.« less

Biredox ionic liquids: new opportunities toward high performance supercapacitors.

PubMed

Bodin, C; Mourad, E; Zigah, D; Le Vot, S; Freunberger, S A; Favier, F; Fontaine, O

2018-01-01

Nowadays commercial supercapacitors are based on purely capacitive storage at the porous carbons that are used for the electrodes. However, the limits that capacitive storage imposes on energy density calls to investigate new materials to improve the capacitance of the device. This new type of electrodes (e.g., RuO 2 , MnO 2 …) involves pseudo-capacitive faradaic redox processes with the solid material. Ion exchange with solid materials is, however, much slower than the adsorption process in capacitive storage and inevitably leads to significant loss of power. Faradaic process in the liquid state, in contrast can be similarly fast as capacitive processes due to the fast ion transport. Designing new devices with liquid like dynamics and improved specific capacitance is challenging. We present a new approach to increase the specific capacitance using biredox ionic liquids, where redox moieties are tethered to the electrolyte ions, allowing high redox concentrations and significant pseudo-capacitive storage in the liquid state. Anions and cations are functionalized with anthraquinone (AQ) and 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) moieties, respectively. Glassy carbon, carbon-onion, and commercial activated carbon electrodes that exhibit different double layer structures and thus different diffusion dynamics were used to simultaneously study the electrochemical response of biredox ionic liquids at the positive and negative electrode.

Shallow transient liquid water environments on present-day mars, and their implications for life

NASA Astrophysics Data System (ADS)

Jones, Eriita G.

2018-05-01

The identification and characterisation of subsurface liquid water environments on Mars are of high scientific interest. Such environments have the potential to support microbial life, and, more broadly, to develop our understanding of the habitability of planets and moons beyond Earth. Given our current state of knowledge of life on Earth, three pre-requisites are necessary for an environment to be considered 'habitable' and therefore capable of supporting terrestrial-like life: energy, biogenic elements, and liquid water with a sufficiently high water activity. The surface of Mars today is predominately cold and dry, and any liquid water exposed to the atmosphere will vaporise or freeze on timescales of hours to days. These conditions have likely persisted for much of the last 10 million years, and perhaps longer. Despite this, briny liquid water flows (Recurrent Slope Linea) have been observed in a number of locations in the present-day. This review examines evidence from the Phoenix Lander (2008) and the Mars Science Laboratory (2012-current), to assess the occurrence of habitable conditions in the shallow Martian regolith. It will be argued that shallow, transient, liquid water brines are potentially habitable by microbial life, are likely a widespread occurrence on Mars, and that future exploration aimed at finding present-day habitable conditions and potential biology should 'follow the salt'.

Measurement of actinides and strontium-90 in high activity waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maxwell, S.L. III; Nelson, M.R.

1994-08-01

The reliable measurement of trace radionuclides in high activity waste is important to support waste processing activities at SRS (F and H Area Waste Tanks, Extended Sludge Processing (ESP) and In-Tank precipitation (ITP) processing). Separation techniques are needed to remove high levels of gamma activity and alpha/beta interferences prior to analytical measurement. Using new extraction chromatographic resins from EiChrom Industries, Inc., the SRS Central Laboratory has developed new high speed separation methods that enable measurement of neptunium, thorium, uranium, plutonium, americium and strontium-90 in high activity waste solutions. Small particle size resin and applied vacuum are used to reduce analysismore » times and enhance column performance. Extraction chromatographic resins are easy to use and eliminate the generation of contaminated liquid organic waste.« less

A new real-time non-coherent to coherent light image converter - The hybrid field effect liquid crystal light valve

NASA Technical Reports Server (NTRS)

Grinberg, J.; Jacobson, A.; Bleha, W.; Miller, L.; Fraas, L.; Boswell, D.; Myer, G.

1975-01-01

A new, high-performance device has been developed for application to real-time coherent optical data processing. The new device embodies a CdS photoconductor, a CdTe light-absorbing layer, a dielectric mirror, and a liquid crystal layer sandwiched between indium-tin-oxide transparent electrodes deposited on optical quality glass flats. The noncoherent image is directed onto the photoconductor; this reduces the impedance of the photoconductor, thereby switching the ac voltage that is impressed across the electrodes onto the liquid crystal to activate the device. The liquid crystal is operated in a hybrid field effect mode. It utilizes the twisted nematic effect to create a dark off-state and the optical birefringence effect to create the bright on-state. The liquid crystal modulates the polarization of the coherent read-out light so an analyzer must be used to create an intensity modulated output beam.

Cold Helium Pressurization for Liquid Oxygen/Liquid Methane Propulsion Systems: Fully-Integrated Hot-Fire Test Results

NASA Technical Reports Server (NTRS)

Morehead, R. L.; Atwell, M. J.; Melcher, J. C.; Hurlbert, E. A.

2016-01-01

Hot-fire test demonstrations were successfully conducted using a cold helium pressurization system fully integrated into a liquid oxygen (LOX) / liquid methane (LCH4) propulsion system (Figure 1). Cold helium pressurant storage at near liquid nitrogen (LN2) temperatures (-275 F and colder) and used as a heated tank pressurant provides a substantial density advantage compared to ambient temperature storage. The increased storage density reduces helium pressurant tank size and mass, creating payload increases of 35% for small lunar-lander sized applications. This degree of mass reduction also enables pressure-fed propulsion systems for human-rated Mars ascent vehicle designs. Hot-fire test results from the highly-instrumented test bed will be used to demonstrate system performance and validate integrated models of the helium and propulsion systems. A pressurization performance metric will also be developed as a means to compare different active pressurization schemes.

Cytotoxic Activity of Salicylic Acid-Containing Drug Models with Ionic and Covalent Binding

PubMed Central

2015-01-01

Three different types of drug delivery platforms based on imidazolium ionic liquids (ILs) were synthesized in high preparative yields, namely, the models involving (i) ionic binding of drug and IL; (ii) covalent binding of drug and IL; and (iii) dual binding using both ionic and covalent approaches. Seven ionic liquids containing salicylic acid (SA-ILs) in the cation or/and in the anion were prepared, and their cytotoxicity toward the human cell lines CaCo-2 (colorectal adenocarcinoma) and 3215 LS (normal fibroblasts) was evaluated. Cytotoxicity of SA-ILs was significantly higher than that of conventional imidazolium-based ILs and was comparable to the pure salicylic acid. It is important to note that the obtained SA-ILs dissolved in water more readily than salicylic acid, suggesting benefits of possible usage of traditional nonsoluble active pharmaceutical ingredients in an ionic liquid form. PMID:26617961

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

PubMed Central

Perosa, Alvise; Guidi, Sandro; Cattelan, Lisa

2016-01-01

Summary The use of ionic liquids (ILs) as organocatalysts is reviewed for transesterification reactions, specifically for the conversion of nontoxic compounds such as dialkyl carbonates to both linear mono-transesterification products or alkylene carbonates. An introductory survey compares pros and cons of classic catalysts based on both acidic and basic systems, to ionic liquids. Then, innovative green syntheses of task-specific ILs and their representative applications are introduced to detail the efficiency and highly selective outcome of ILs-catalyzed transesterification reactions. A mechanistic hypothesis is discussed by the concept of cooperative catalysis based on the dual (electrophilic/nucleophilic) activation of reactants. PMID:27829898

Advanced SLMs for microscopy

NASA Astrophysics Data System (ADS)

Linnenberger, A.

2018-02-01

Wavefront shaping devices such as deformable mirrors, liquid crystal spatial light modulators (SLMs), and active lenses are of considerable interest in microscopy for aberration correction, volumetric imaging, and programmable excitation. Liquid crystal SLMs are high resolution phase modulators capable of creating complex phase profiles to reshape, or redirect light within a three-dimensional (3D) volume. Recent advances in Meadowlark Optics (MLO) SLMs reduce losses by increasing fill factor from 83.4% to 96%, and improving resolution from 512 x 512 pixels to 1920 x 1152 pixels while maintaining a liquid crystal response time of 300 Hz at 1064 nm. This paper summarizes new SLM capabilities, and benefits for microscopy.

Experiments on microjets of undercooled liquid hydrogen

NASA Astrophysics Data System (ADS)

Fernández, José M.; Kühnel, Matthias; Tejeda, Guzmán; Kalinin, Anton; Grisenti, Robert E.; Montero, Salvador

2012-11-01

Novel experiments on liquid microjets (filaments) of hydrogen and deuterium, carried out at the Laboratory of Molecular Fluid Dynamics of the IEM, are reported. These filaments, less than 10 microns in diameter, are an ideal medium to produce highly undercooled liquid samples and to investigate the homogeneous solidification process, free from wall effects. The filaments exit from cryogenic capillary nozzles into a vacuum chamber, to cool down very fast by surface evaporation. Finite size radius leads to a temperature gradient across the filament, determined by thermal conductivity, and, possibly, to a velocity gradient as well. The filaments are monitored by laser shadowgraphy, and analyzed by means of high performance Raman spectroscopy. Real-time measurements in the rotational and vibrational spectral regions reveal the structure and temperature along the filaments, allowing to track the crystal growth process. The high spatial resolution of Raman spectroscopy allows observing in situ the structural changes of the liquid microjets, with a time resolution of ˜ 10 ns. The filaments of pure para-H2 can be cooled down to 9 K (65% of its melting point at 13.8 K), while staying liquid, before eventually solidifying into a metastable polymorph. Crystallization kinetics revealed a growth rate of 33 cm/s, much higher than expected for a thermally activated process. The time and spatial control attained in these experiments offers new opportunities for investigating the processes of nonequilibrium phase transformations in undercooled fluids, as well as the propagation of liquid jets into a rarefied gas media.

Mesoporous and biocompatible surface active silica aerogel synthesis using choline formate ionic liquid.

PubMed

Meera, Kamal Mohamed Seeni; Sankar, Rajavelu Murali; Jaisankar, Sellamuthu N; Mandal, Asit Baran

2011-09-01

In this paper, we report the preparation and characterization of mesoporous and biocompatible transparent silica aerogel by the sol-gel polymerization of tetraethyl orthosilicate using ionic liquid. Choline cation based ionic liquid allows the silica framework to form in a non collapsing environment and controls the pore size of the gel. FT-IR spectra reveal the interaction of ionic liquid with surface -OH of the gel. DSC thermogram giving the evidence of confinement of ionic liquid within the silica matrix, which helps to avoid the shrinkage of the gel during the aging process. Nitrogen sorption measurements of gel prepared with ionic liquid exhibit a low surface area of 100.53 m2/g and high average pore size of 3.74 nm. MTT assay proves the biocompatibility and cell viability of the prepared gels. This new nanoporous silica material can be applied to immobilize biological molecules, which may retain their stability over a longer period. Copyright © 2011 Elsevier B.V. All rights reserved.

Mechanisms for microvascular damage induced by ultrasound-activated microbubbles

NASA Astrophysics Data System (ADS)

Chen, Hong; Brayman, Andrew A.; Evan, Andrew P.; Matula, Thomas J.

2012-10-01

To provide insight into the mechanisms of microvascular damage induced by ultrasound-activated microbubbles, experimental studies were performed to correlate microvascular damage to the dynamics of bubble-vessel interactions. High-speed photomicrography was used to record single microbubbles interacting with microvessels in ex vivo tissue, under the exposure of short ultrasound pulses with a center frequency of 1 MHz and peak negative pressures (PNP) ranging from 0.8-4 MPa. Vascular damage associated with observed bubble-vessel interactions was either indicated directly by microbubble extravasation or examined by transmission electron microscopy (TEM) analyses. As observed previously, the high-speed images revealed that ultrasound-activated microbubbles could cause distention and invagination of adjacent vessel walls, and could form liquid jets in microvessels. Vessel distention, invagination, and liquid jets were associated with the damage of microvessels whose diameters were smaller than those of maximally expanded microbubbles. However, vessel invagination appeared to be the dominant mechanism for the damage of relative large microvessels.

Mechanisms for microvascular damage induced by ultrasound-activated microbubbles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Hong; Brayman, Andrew A.; Evan, Andrew P.

To provide insight into the mechanisms of microvascular damage induced by ultrasound-activated microbubbles, experimental studies were performed to correlate microvascular damage to the dynamics of bubble-vessel interactions. High-speed photomicrography was used to record single microbubbles interacting with microvessels in ex vivo tissue, under the exposure of short ultrasound pulses with a center frequency of 1 MHz and peak negative pressures (PNP) ranging from 0.8-4 MPa. Vascular damage associated with observed bubble-vessel interactions was either indicated directly by microbubble extravasation or examined by transmission electron microscopy (TEM) analyses. As observed previously, the high-speed images revealed that ultrasound-activated microbubbles could cause distentionmore » and invagination of adjacent vessel walls, and could form liquid jets in microvessels. Vessel distention, invagination, and liquid jets were associated with the damage of microvessels whose diameters were smaller than those of maximally expanded microbubbles. However, vessel invagination appeared to be the dominant mechanism for the damage of relative large microvessels.« less

A combined A431 cell membrane chromatography and online high performance liquid chromatography/mass spectrometry method for screening compounds from total alkaloid of Radix Caulophylli acting on the human EGFR.

PubMed

Sun, Meng; Ren, Jing; Du, Hui; Zhang, Yanmin; Zhang, Jie; Wang, Sicen; He, Langchong

2010-10-15

We have developed an online analytical method that combines A431 cell membrane chromatography (A431/CMC) with high performance liquid chromatography and mass spectrometry (LC/MS) for identifying active components from Radix Caulophylli acting on human EGFR. Retention fractions on A431/CMC model were captured onto an enrichment column and the components were directly analyzed by combining a 10-port column switcher with an LC/MS system for separation and preliminary identification. Using Sorafenib tosylate as a positive control, taspine and caulophine from Radix Caulophylli were identified as the active molecules which could act on the EGFR. This A431/CMC-online-LC/MS method can be applied for screening active components acting on EGFR from traditional Chinese medicines exemplified by Radix Caulophylli and will be of great utility in drug discovery using natural medicinal herbs as a source of novel compounds. Copyright © 2010 Elsevier B.V. All rights reserved.

Active Uptake of Amino Acids by Leaves of an Epiphytic Vascular Plant, Tillandsia paucifolia (Bromeliaceae).

PubMed

Nyman, L P; Davis, J P; O'dell, S J; Arditti, J; Stephens, G C; Benzing, D H

1987-03-01

Specialized epidermal trichomes on the leaves of the epiphyte, Tillandsia paucifolia (Bromeliaceae) accumulate amino acids from solution. Simultaneous net uptake of 17 amino acids was determined using high performance liquid chromatography. Uptake occurs against concentration gradients at least as high as 10(4).

One molecule of ionic liquid and tert-alcohol on a polystyrene-support as catalysts for efficient nucleophilic substitution including fluorination.

PubMed

Shinde, Sandip S; Patil, Sunil N

2014-12-07

The tert-alcohol and ionic liquid solvents in one molecule [mim-(t)OH][OMs] was immobilized on polystyrene and reported to be a highly efficient catalyst in aliphatic nucleophilic substitution using alkali metal salts. Herein, we investigated the catalytic activity of a new structurally modified polymer-supported tert-alcohol functionalized imidazolium salt catalyst in nucleophilic substitution of 2-(3-methanesulfonyloxypropyoxy)naphthalene as a model substrate with various metal nucleophiles. The tert-alcohol moiety of the ionic liquid with a hexyl chain distance from polystyrene had a better catalytic activity compared to the other resin which lacked an alkyl linker and tert-alcohol moiety. We found that the maximum [mim-(t)OH][OMs] loading had the best catalytic efficacy among the tested polystyrene-based ionic liquids (PSILs) in nucleophilic fluorination. The catalytic efficiency of the PS[him-(t)OH][OMs] as a phase transfer catalyst (PTC) was determined by carrying out various nucleophilic substitutions using the corresponding alkali metal salts from the third to sixth periodic in CH3CN or tert-BuOH media. The scope of this protocol with primary and secondary polar substrates containing many heteroatoms is also reported. This PS[him-(t)OH][OMs] catalyst not only enhances the reactivity of alkali metal salts and reduces the formation of by-products but also affords high yield with easy isolation.

Field Demonstration of Biologically Active Zone Enhancement (BAZE) for In Situ RDX Degradation in Groundwater

DTIC Science & Technology

2010-07-01

Used Defense Site GAC granular activated carbon HA health advisory HFCS high fructose corn syrup HMX octahydro-1,3,5,7-tetranitro 1,3,5,7... fructose corn syrup (HFCS) by injection is another innovative alternative and was demonstrated at Milan Army Ammunition Plant. Data needed for comparison...tetrazocine HPLC high pressure liquid chromatograph HVAC heating, ventilation, and air conditioning ID inside diameter IW injection well MNX

Establishment of quantitative retention-activity model by optimized microemulsion liquid chromatography.

PubMed

Xu, Liyuan; Gao, Haoshi; Li, Liangxing; Li, Yinnong; Wang, Liuyun; Gao, Chongkai; Li, Ning

2016-12-23

The effective permeability coefficient is of theoretical and practical importance in evaluation of the bioavailability of drug candidates. However, most methods currently used to measure this coefficient are expensive and time-consuming. In this paper, we addressed these problems by proposing a new measurement method which is based on the microemulsion liquid chromatography. First, the parallel artificial membrane permeability assays model was used to determine the effective permeability of drug so that quantitative retention-activity relationships could be established, which were used to optimize the microemulsion liquid chromatography. The most effective microemulsion system used a mobile phase of 6.0% (w/w) Brij35, 6.6% (w/w) butanol, 0.8% (w/w) octanol, and 86.6% (w/w) phosphate buffer (pH 7.4). Next, support vector machine and back-propagation neural networks are employed to develop a quantitative retention-activity relationships model associated with the optimal microemulsion system, and used to improve the prediction ability. Finally, an adequate correlation between experimental value and predicted value is computed to verify the performance of the optimal model. The results indicate that the microemulsion liquid chromatography can serve as a possible alternative to the PAMPA method for determination of high-throughput permeability and simulation of biological processes. Copyright © 2016. Published by Elsevier B.V.

Analysis of partial discharge activity by a conducting particle in liquid nitrogen under AC voltages adopting UHF technique

NASA Astrophysics Data System (ADS)

Sarathi, R.; Giridhar, A. V.; Sethupathi, K.

2010-01-01

Liquid nitrogen (LN 2) is used as an insulant as well as coolant in high temperature superconducting power equipments. Particle contamination in liquid nitrogen is one of the major cause for formation of partial discharges during operation. An attempt has been made in the present study to understand the feasibility of using Ultra High Frequency (UHF) sensors for identification of partial discharge (PD) formed due to particle movement in liquid nitrogen under AC voltages. It is observed that the partial discharge formed in LN 2 radiates UHF signal. The results of the study indicate that the conventional partial discharge measurement and UHF peak amplitude measurement have direct correlation. The Phase Resolved Partial Discharge (PRPD) analysis indicates that the partial discharge formed due to particle movement occurs in the entire phase windows of the AC voltage. The PD magnitude increases with increase in applied voltage. The frequency content of UHF signal generated due to particle movement in liquid nitrogen under AC voltages lies in the range of 0.5-1.5 GHz. The UHF sensor output signal analyzed using spectrum analyzer by operating it in zero-span mode, indicates that burst type PD occurs due to particle movement.

Reflective liquid crystal light valve with hybrid field effect mode

NASA Technical Reports Server (NTRS)

Boswell, Donald D. (Inventor); Grinberg, Jan (Inventor); Jacobson, Alexander D. (Inventor); Myer, Gary D. (Inventor)

1977-01-01

There is disclosed a high performance reflective mode liquid crystal light valve suitable for general image processing and projection and particularly suited for application to real-time coherent optical data processing. A preferred example of the device uses a CdS photoconductor, a CdTe light absorbing layer, a dielectric mirror, and a liquid crystal layer sandwiched between indium-tin-oxide transparent electrodes deposited on optical quality glass flats. The non-coherent light image is directed onto the photoconductor; this reduces the impedance of the photoconductor, thereby switching the AC voltage that is impressed across the electrodes onto the liquid crystal to activate the device. The liquid crystal is operated in a hybrid field effect mode. It utilizes the twisted nematic effect to create a dark off-state (voltage off the liquid crystal) and the optical birefringence effect to create the bright on-state. The liquid crystal thus modulates the polarization of the coherent read-out or projection light responsively to the non-coherent image. An analyzer is used to create an intensity modulated output beam.

Determination of dasatinib in the tablet dosage form by ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis.

PubMed

Gonzalez, Aroa Garcia; Taraba, Lukáš; Hraníček, Jakub; Kozlík, Petr; Coufal, Pavel

2017-01-01

Dasatinib is a novel oral prescription drug proposed for treating adult patients with chronic myeloid leukemia. Three analytical methods, namely ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis, were developed, validated, and compared for determination of the drug in the tablet dosage form. The total analysis time of optimized ultra high performance liquid chromatography and capillary zone electrophoresis methods was 2.0 and 2.2 min, respectively. Direct ultraviolet detection with detection wavelength of 322 nm was employed in both cases. The optimized sequential injection analysis method was based on spectrophotometric detection of dasatinib after a simple colorimetric reaction with folin ciocalteau reagent forming a blue-colored complex with an absorbance maximum at 745 nm. The total analysis time was 2.5 min. The ultra high performance liquid chromatography method provided the lowest detection and quantitation limits and the most precise and accurate results. All three newly developed methods were demonstrated to be specific, linear, sensitive, precise, and accurate, providing results satisfactorily meeting the requirements of the pharmaceutical industry, and can be employed for the routine determination of the active pharmaceutical ingredient in the tablet dosage form. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pressure Dependence of Komatiite Liquid Viscosity and Implications for Magma Ocean Rheology

NASA Astrophysics Data System (ADS)

O'Dwyer Brown, L.; Lesher, C. E.; Terasaki, H. G.; Yamada, A.; Sakamaki, T.; Shibazaki, Y.; Ohtani, E.

2009-12-01

The viscosities of komatiite liquids at high pressures and temperatures were investigated using the in-situ falling sphere technique at BL04B1, SPring-8. Komatiites are naturally occurring magmas, rich in network modifying cations. Despite the refractory and fluid nature of komatiite, we successfully measured the viscosity of molten komatiites from Gorgona Island, Colombia (MgO = 17.8 wt.%; NBO/T = 1.5) between 11 and 13 GPa at 2000 C, and from Belingwe, Zimbabwe (MgO = 28.14 wt.%; NBO/T = 2.1) from 12 to 14 GPa at 2000 C. Under isothermal conditions, the viscosity of Gorgona Island komatiite melt increased with pressure, consistent with our previous measurements at lower pressures for this composition. We interpreted this positive pressure dependence as the result of reductions in interatomic space diminishing the free volume of the liquid when compressed. The viscosity of molten komatiite from Belingwe also increased up to 12 GPa, however between 12 and 14 GPa the viscosity is nearly constant. In previous studies of depolymerized silicate liquids, the pressure dependence of viscosity has been shown to reverse from positive to negative between 8 and 10 GPa with corresponding changes in activation volume [1] [2]. In contrast, the activation volume for Belingwe liquid decreases to near zero, but does not become negative above 11 GPa. Similarly, the activation volume for Gorgona Island komatiite remains positive throughout the pressure range investigated. Molecular dynamics simulations of simple MgO-SiO2 liquids with NBO/T > 2 also show a positive pressure dependence, reflecting the dominant control of free-volume reduction on the viscosity of depolymerized melts. However, the more rapid reduction in activation volume with pressure in komatiite liquids may be related to the presence of Al, Ti and other cations that interact and undergo coordination changes unavailable in simple silicate liquids. Along Hadean and post-Hadean mantle adiabats the net effect of temperature and pressure on ultramafic liquids suggests that changes in viscosity are likely modest and viscosity will decrease with depth. Stiffening and isolation of the lower regions of a magma ocean due to increasing melt viscosity seem unlikely. [1] PEPI (2003) 139, 45 [2] EPSL (2005) 240, 589

Topological sound in active-liquid metamaterials

NASA Astrophysics Data System (ADS)

Souslov, Anton; van Zuiden, Benjamin C.; Bartolo, Denis; Vitelli, Vincenzo

2017-11-01

Liquids composed of self-propelled particles have been experimentally realized using molecular, colloidal or macroscopic constituents. These active liquids can flow spontaneously even in the absence of an external drive. Unlike spontaneous active flow, the propagation of density waves in confined active liquids is not well explored. Here, we exploit a mapping between density waves on top of a chiral flow and electrons in a synthetic gauge field to lay out design principles for artificial structures termed topological active metamaterials. We design metamaterials that break time-reversal symmetry using lattices composed of annular channels filled with a spontaneously flowing active liquid. Such active metamaterials support topologically protected sound modes that propagate unidirectionally, without backscattering, along either sample edges or domain walls and despite overdamped particle dynamics. Our work illustrates how parity-symmetry breaking in metamaterial structure combined with microscopic irreversibility of active matter leads to novel functionalities that cannot be achieved using only passive materials.

Liquid Nitrogen Zero Boiloff Testing

NASA Technical Reports Server (NTRS)

Plachta, David; Feller, Jeffrey; Johnson, Wesley; Robinson, Craig

2017-01-01

Cryogenic propellants such as liquid hydrogen (LH2) and liquid oxygen (LO2) are a part of NASAs future space exploration due to their high specific impulse for rocket motors of upper stages suitable for transporting 10s to 100s of metric tons of payload mass to destinations outside of low earth orbit and for their return. However, the low storage temperatures of LH2 and LO2 cause substantial boil-off losses for missions with durations greater than several months. These losses can be eliminated by incorporating high performance cryocooler technology to intercept heat load to the propellant tanks and modulating the cryocooler to control tank pressure. The active thermal control technology being developed by NASA is the reverse turbo-Brayton cycle cryocooler and its integration to the propellant tank through a distributed cooling tubing network coupled to the tank wall. This configuration was recently tested at NASA Glenn Research Center, in a vacuum chamber and cryo-shroud that simulated the essential thermal aspects of low Earth orbit, its vacuum and temperature. Testing consisted of three passive tests with the active cryo-cooler system off, and 7 active tests, with the cryocooler powered up. The test matrix included zero boil-off tests performed at 90 full and 25 full, and several demonstrations at excess cooling capacity and reduced cooling capacity. From this, the tank pressure response with varied cryocooler power inputs was determined. This test series established that the active cooling system integrated with the propellant tank eliminated boil-off and robustly controlled tank pressure.

From functional food to medicinal product: Systematic approach in analysis of polyphenolics from propolis and wine

PubMed Central

Medić-Šarić, Marica; Rastija, Vesna; Bojić, Mirza; Maleš, Željan

2009-01-01

In the last decade we have been working on standardization of propolis extract and determination of active constituents of wine those are rich in polyphenolics and have nutritional as well as therapeutic value. Here we are summarizing our results and providing overview on systematic approach how to analyse natural products rich in flavonoids and phenolic acids. Chromatographic methods (thin layer chromatography and high performance liquid chromatography) were used for identification, quantification, and characterization of individual flavonoid or phenolic acid. Total content of active constituents and antioxidant activity were determined by spectrophotometry. Pharmacokinetic parameters were determined by high performance liquid chromatography and using appropriate software. Quantitative structure-activity relationship study of antioxidant activity was conducted, as well as assessment of prolonged propolis supplementation on antioxidative status of organism. Thin layer chromatography-densitometry has been proven as quick and reliable method for standard analysis of propolis and wine; the best mobile phase being chloroform – methanol – formic acid (98–100%) in ratio 44 : 3.5 : 2.5 (v/v). Higher number of polyphenolics was determined by high performance liquid chromatography; 15 compared to 9 by thin layer chromatography. Interactions in situ with acetylsalicylic acid were detected with most of polyphenolics analysed. Plasma protein binding and blood-barrier penetration was greatest for flavone. The interactions with human serum albumin have been grater than 95% for all flavonoids analysed. The prolonged propolis consumption increased superoxide dismutase activity. The necessity of standardization of natural products and their registration as functional nutraceuticals demand easy, quick and inexpensive methods of analysis. In this work we provided overview of analytical part for polyphenolics that could be used as data for possible registration of final products either as functional food or medicinal product. This feature introduces the readers to the authors' research through a concise overview of the selected topic. Reference to important work from others in the field is included. PMID:19624827

Optimized ultra-high-pressure-assisted extraction of procyanidins from lychee pericarp improves the antioxidant activity of extracts.

PubMed

Zhang, Ruifen; Su, Dongxiao; Hou, Fangli; Liu, Lei; Huang, Fei; Dong, Lihong; Deng, Yuanyuan; Zhang, Yan; Wei, Zhencheng; Zhang, Mingwei

2017-08-01

To establish optimal ultra-high-pressure (UHP)-assisted extraction conditions for procyanidins from lychee pericarp, a response surface analysis method with four factors and three levels was adopted. The optimum conditions were as follows: 295 MPa pressure, 13 min pressure holding time, 16.0 mL/g liquid-to-solid ratio, and 70% ethanol concentration. Compared with conventional ethanol extraction and ultrasonic-assisted extraction methods, the yields of the total procyanidins, flavonoids, and phenolics extracted using the UHP process were significantly increased; consequently, the oxygen radical absorbance capacity and cellular antioxidant activity of UHP-assisted lychee pericarp extracts were substantially enhanced. LC-MS/MS and high-performance liquid chromatography quantification results for individual phenolic compounds revealed that the yield of procyanidin compounds, including epicatechin, procyanidin A2, and procyanidin B2, from lychee pericarp could be significantly improved by the UHP-assisted extraction process. This UHP-assisted extraction process is thus a practical method for the extraction of procyanidins from lychee pericarp.

High temperature two component explosive

DOEpatents

Mars, James E.; Poole, Donald R.; Schmidt, Eckart W.; Wang, Charles

1981-01-01

A two component, high temperature, thermally stable explosive composition comprises a liquid or low melting oxidizer and a liquid or low melting organic fuel. The oxidizer and fuel in admixture are incapable of substantial spontaneous exothermic reaction at temperatures on the order of 475.degree. K. At temperatures on the order of 475.degree. K., the oxidizer and fuel in admixture have an activation energy of at least about 40 kcal/mol. As a result of the high activation energy, the preferred explosive compositions are nondetonable as solids at ambient temperature, and become detonable only when heated beyond the melting point. Preferable oxidizers are selected from alkali or alkaline earth metal nitrates, nitrites, perchlorates, and/or mixtures thereof. Preferred fuels are organic compounds having polar hydrophilic groups. The most preferred fuels are guanidinium nitrate, acetamide and mixtures of the two. Most preferred oxidizers are eutectic mixtures of lithium nitrate, potassium nitrate and sodium nitrate, of sodium nitrite, sodium nitrate and potassium nitrate, and of potassium nitrate, calcium nitrate and sodium nitrate.

Biotransformation of anthelmintics and the activity of drug-metabolizing enzymes in the tapeworm Moniezia expansa.

PubMed

Prchal, Lukáš; Bártíková, Hana; Bečanová, Aneta; Jirásko, Robert; Vokřál, Ivan; Stuchlíková, Lucie; Skálová, Lenka; Kubíček, Vladimír; Lamka, Jiří; Trejtnar, František; Szotáková, Barbora

2015-04-01

The sheep tapeworm Moniezia expansa is very common parasite, which affects ruminants such as sheep, goats as well as other species. The benzimidazole anthelmintics albendazole (ABZ), flubendazole (FLU) and mebendazole (MBZ) are often used to treat the infection. The drug-metabolizing enzymes of helminths may alter the potency of anthelmintic treatment. The aim of our study was to assess the activity of the main drug-metabolizing enzymes and evaluate the metabolism of selected anthelmintics (ABZ, MBZ and FLU) in M. expansa. Activities of biotransformation enzymes were determined in subcellular fractions. Metabolites of the anthelmintics were detected and identified using high performance liquid chromatography/ultra-violet/VIS/fluorescence or ultra-high performance liquid chromatography/mass spectrometry. Reduction of MBZ, FLU and oxidation of ABZ were proved as well as activities of various metabolizing enzymes. Despite the fact that the conjugation enzymes glutathione S-transferase, UDP-glucuronosyl transferase and UDP-glucosyl transferase were active in vitro, no conjugated metabolites of anthelmintics were identified either ex vivo or in vitro. The obtained results indicate that sheep tapeworm is able to deactivate the administered anthelmintics, and thus protects itself against their action.

Electropolymerized polyazulene as active material in flexible supercapacitors

NASA Astrophysics Data System (ADS)

Suominen, Milla; Lehtimäki, Suvi; Yewale, Rahul; Damlin, Pia; Tuukkanen, Sampo; Kvarnström, Carita

2017-07-01

We report the capacitive behavior of electrochemically polymerized polyazulene films in different ionic liquids. The ionic liquids in this study represent conventional imidazolium based ionic liquids with tetrafluoroborate and bis(trifluoromethylsulfonyl)imide anions as well as an unconventional choline based ionic liquid. The effect of different ionic liquids on the polymerization and capacitive performance of polyazulene films is demonstrated by cyclic voltammetry and electrochemical impedance spectroscopy in a 3-electrode cell configuration. The films exhibit the highest capacitances in the lowest viscosity ionic liquid (92 mF cm-2), while synthesis in high viscosity ionic liquid shortens the conjugation length and results in lower electroactivity (25 mF cm-2). The obtained films also show good cycling stabilities retaining over 90% of their initial capacitance over 1200 p-doping cycles. We also demonstrate, for the first time, flexible polyazulene supercapacitors of symmetric and asymmetric configurations using the choline based ionic liquid as electrolyte. In asymmetric configuration, capacitance of 55 mF (27 mF cm-2) with an equivalent series resistance of 19 Ω is obtained at operating voltage of 1.5 V. Upon increasing the operating voltage up to 2.4 V, the capacitance increases to 72 mF (36 mF cm-2).

Thermodynamics of Pb17Li-bismuth interactions

NASA Astrophysics Data System (ADS)

Hubberstey, Peter; Sample, Tony

1994-09-01

Thermodynamic calculations of the PbBiLi ternary system have been completed to rationalise the formation of solid Li 3Bi on reaction of liquid Pb17Li with bismuth. At 723 K, the bismuth activity in equilibrium with liquid Pi17Li and solid Li 3Bi is calculated to be 9.50 × 10 -4; this can be correlated to a solubility of 2.09 × 10 -1 mol% Bi(2520 wppm). The corresponding bismuth activity in equilibrium with liquid Pb17Li and solid LiBi is 5.04 × 10 -2 (an extrapolated value as LiBi decomposes peritectically at 688 K). The minimum lithium content of PbLi alloys required to react with unit activity bismuth to form Li 3Bi at 723 K is calculated to be ˜ 1.8 mol% Li. The dominance of Li 3Bi in the PbBiLi system is attributed to its extreme stability as evidenced by both its high melting point (1418 K) and free energy of formation [ ΔGf0(Li 3Bi, c 723 K) = 212.8 kJ mol -1].

Mosapride Accelerates the Delayed Gastric Emptying of High-Viscosity Liquids: A Crossover Study Using Continuous Real-Time 13C Breath Test (BreathID System)

PubMed Central

Sakamoto, Yasunari; Sekino, Yusuke; Yamada, Eiji; Ohkubo, Hidenori; Higurashi, Takuma; Sakai, Eiji; Iida, Hiroshi; Hosono, Kunihiro; Endo, Hiroki; Nonaka, Takashi; Ikeda, Tamon; Fujita, Koji; Yoneda, Masato; Koide, Tomoko; Takahashi, Hirokazu; Goto, Ayumu; Abe, Yasunobu; Gotoh, Eiji; Maeda, Shin; Nakajima, Atsushi

2011-01-01

Background/Aims The administration of liquid nutrients to patients is often accompanied by complications such as gastroesophageal reflux. To prevent gastroesophageal reflux, high-viscosity liquid meals are used widely, however, it still remains controversial whether high-viscosity liquid meals have any effect on the rate of gastric emptying. The present study was conducted with the aim of determining whether high-viscosity liquid meals had any effect on the rate of gastric emptying and mosapride might accelerate the rate of gastric emptying of high-viscosity liquid meals. Methods Six healthy male volunteers underwent 3 tests at intervals of > 1 week. After fasting for > 8 hours, each subject received one of three test meals (liquid meal only, high-viscosity liquid meal [liquid meal plus pectin] only, or high-viscosity liquid meal 30 minutes after intake of mosapride). A 13C-acetic acid breath test was performed, which monitored the rate of gastric emptying for 4 hours. Using the Oridion Research Software (β version), breath test parameters were calculated. The study parameters were examined for all the 3 test conditions and compared using the Freidman test. Results Gastric emptying was significantly delayed following intake of a high-viscosity liquid meal alone as compared with a liquid meal alone; however, intake of mosapride prior to a high-viscosity liquid meal was associated with a significantly accelerated rate of gastric emptying as compared with a high-viscosity liquid meal alone. Conclusions This study showed that high-viscosity liquid meals delayed gastric emptying: however, mosapride recovered the delayed rate of gastric emptying by high-viscosity liquid meals. PMID:22148109

Enzyme activity in dialkyl phosphate ionic liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, M.F.; Dunn, J.; Li, L.-L.

2011-12-01

The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariellavolvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v.

The analysis of the wavefront aberration caused by the gravity of the tunable-focus liquid-filled membrane lens

NASA Astrophysics Data System (ADS)

Zhang, Wei; Liu, Pengfei; Wei, Xiaona; Zhuang, Songlin; Yang, Bo

2010-11-01

Liquid lens is a novel optical device which can implement active zooming. With liquid lens, zoom camera can be designed with more miniature size and simpler structure than before. It is thought that the micro zoom system with liquid lens has a very wide potential applications in many fields, in which the volume and weight of the system are critically limited, such as endoscope, mobile, PDA and so on. There are mainly three types of tunable-focus liquid lens: liquid crystal lens, electrowetting effect based liquid lens and liquid-filled membrane lens. Comparing with the other two kinds of liquid lens, the liquid-filled membrane lens has the advantages of simple structure, flexible aperture and high zooming efficiency. But its membrane surface will have an initial shape deformation caused by the gravity when the aperture of the lens is at large size, which will lead to the wave front aberration and the imaging quality impairing. In this paper, the initial deformation of the lens caused by the gravity was simulated based on the theory of Elastic Mechanics, which was calculated by the Finite Element Analysis method. The relationship between the diameter of the lens and the wave front aberration caused by the gravity was studied. And the Optical path difference produced by different liquid density was also analyzed.

Aerosol partitioning in natural mixed-phase clouds

NASA Astrophysics Data System (ADS)

Henning, S.; Bojinski, S.; Diehl, K.; Ghan, S.; Nyeki, S.; Weingartner, E.; Wurzler, S.; Baltensperger, U.

2004-03-01

In situ aerosol and cloud drop microphysical measurements at a high-alpine site are used to investigate aerosol partitioning between cloud and interstitial phases in natural, mid-latitude, mixed-phase clouds. Measurements indicate a decrease in the activated aerosol fraction (FN) for particle diameters dP > 100 nm with cloud temperature from FN ~ 0.54 in summer liquid-phase clouds to FN ~ 0.08 in winter mixed-phase clouds. The latter may be attributed to the Bergeron-Findeisen mechanism whereby ice crystals grow at the expense of liquid water drops, releasing formerly activated aerosols back into the interstitial phase. This provides a means to distinguish the indirect effects of aerosols on drops and ice crystals.

INTERNATIONAL CONFERENCE ON SEMICONDUCTOR INJECTION LASERS SELCO-87: High-performance 1.3-μm InGaAsP/InP heterostructures formed by two-phase liquid epitaxy

NASA Astrophysics Data System (ADS)

Novotný, J.; Procházková, O.; Šrobár, F.; Zelinka, J.

1988-11-01

A description is given of a two-phase liquid epitaxy method used to grow InGaAsP/InP heterostructures intended for injection lasers emitting in the 1.3-μm range. A study was made of heterostructures of three types: double, with an additional quaternary layer (λ approx 1.1 μm) adjoining the active layer; with two quaternary layers between the active layer and the InP confining layers. The configuration with two flanking quaternary layers was found to be the best from the point of view of the threshold current density, optical output power, and reproducibility.

Layer cathode methods of manufacturing and materials for Li-ion rechargeable batteries

DOEpatents

Kang, Sun-Ho [Naperville, IL; Amine, Khalil [Downers Grove, IL

2008-01-01

A positive electrode active material for lithium-ion rechargeable batteries of general formula Li.sub.1+xNi.sub..alpha.Mn.sub..beta.A.sub..gamma.O.sub.2 and further wherein A is Mg, Zn, Al, Co, Ga, B, Zr, or Ti and 0

Isolation and purification of an early pregnancy factor-like molecule from culture supernatants obtained from lymphocytes of pregnant women: II. Identification of the molecule as a Fc-receptor-like molecule: a preliminary report.

PubMed

Aranha, C; Bordekar, A; Shahani, S

1998-11-01

Early pregnancy factor (EPF)-like activity from culture supernatants obtained from stimulated lymphocytes of pregnant women was characterized and identified. The enzyme-linked immunosorbent assay depending on the presence of "Fc" receptors on bovine spermatozoa was used to identify the EPF-like molecule purified by gel filtration and reverse-phase high-performance liquid chromatography. The results indicated that the crude lymphocyte culture supernatant, the EPF-positive G IV fraction obtained on gel filtration, and the EPF-positive reverse-phase high-performance liquid chromatography protein readily bound with the different concentrations of aggregated human gamma-globulin in a manner similar to that in which the standard control of aggregated human gamma-globulin binds to the bovine spermatozoa. EPF-like activity synthesized and secreted by lymphocytes during pregnancy may be a Fc-receptor-like molecule.

A nonradioactive high-performance liquid chromatographic microassay for uridine 5'-monophosphate synthase, orotate phosphoribosyltransferase, and orotidine 5'-monophosphate decarboxylase.

PubMed

Krungkrai, J; Wutipraditkul, N; Prapunwattana, P; Krungkrai, S R; Rochanakij, S

2001-12-15

A novel nonradioactive, microassay method has been developed to determine simultaneously the two enzymatic activities of orotate phosphoribosyltransferase (OPRTase) and orotidine 5'-monophosphate decarboxylase (ODCase), either as a bifunctional protein (uridine 5'-monophosphate synthase, UMPS) or as separate enzymes. Substrates (orotate for OPRTase or orotidine 5'-monophosphate for ODCase) and a product (UMP) of the enzymatic assay were separated by high-performance liquid chromatography (HPLC) using a reversed-phase column and an ion-pairing system; the amount of UMP was quantified by dual-wavelength uv detection at 260 and 278 nm. This HPLC assay can easily detect picomole levels of UMP in enzymatic reactions using low specific activity UMPS of mammalian cell extracts, which is difficult to do with the other nonradioactive assays that have been described. The HPLC assay is suitable for use in protein purification and for kinetic study of these enzymes. (c)2001 Elsevier Science.

Identification of an ACE-Inhibitory Peptide from Walnut Protein and Its Evaluation of the Inhibitory Mechanism.

PubMed

Wang, Cong; Tu, Maolin; Wu, Di; Chen, Hui; Chen, Cheng; Wang, Zhenyu; Jiang, Lianzhou

2018-04-11

In the present study, a novel angiotensin I-converting enzyme inhibitory (ACE inhibitory) peptide, EPNGLLLPQY, derived from walnut seed storage protein, fragment residues 80-89, was identified by ultra-high performance liquid chromatography electrospray ionization quadrupole time of flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) from walnut protein hydrolysate. The IC 50 value of the peptide was 233.178 μM, which was determined by the high performance liquid chromatography method by measuring the amount of hippuric acid (HA) generated from the ACE decomposition substrate (hippuryl-l-histidyl-l-leucine (HHL) to assess the ACE activity. Enzyme inhibitory kinetics of the peptide against ACE were also conducted, by which the inhibitory mechanism of ACE-inhibitory peptide was confirmed. Moreover, molecular docking was simulated by Discovery Studio 2017 R2 software to provide the potential mechanisms underlying the ACE-inhibitory activity of EPNGLLLPQY.

Antioxidant White Grape Seed Phenolics: Pressurized Liquid Extracts from Different Varieties

PubMed Central

Garcia-Jares, Carmen; Vazquez, Alberto; Lamas, Juan P.; Pajaro, Marta; Alvarez-Casas, Marta; Lores, Marta

2015-01-01

Grape seeds represent a high percentage (20% to 26%) of the grape marc obtained as a byproduct from white winemaking and keep a vast proportion of grape polyphenols. In this study, seeds obtained from 11 monovarietal white grape marcs cultivated in Northwestern Spain have been analyzed in order to characterize their polyphenolic content and antioxidant activity. Seeds of native (Albariño, Caiño, Godello, Loureiro, Torrontés, and Treixadura) and non-native (Chardonnay, Gewurtzträminer, Pinot blanc, Pinot gris, and Riesling) grape varieties have been considered. Low weight phenolics have been extracted by means of pressurized liquid extraction (PLE) and further analyzed by LC-MS/MS. The results showed that PLE extracts, whatever the grape variety of origin, contained large amounts of polyphenols and high antioxidant activity. Differences in the varietal polyphenolic profiles were found, so a selective exploitation of seeds might be possible. PMID:26783956

Bubble pump: scalable strategy for in-plane liquid routing.

PubMed

Oskooei, Ali; Günther, Axel

2015-07-07

We present an on-chip liquid routing technique intended for application in well-based microfluidic systems that require long-term active pumping at low to medium flowrates. Our technique requires only one fluidic feature layer, one pneumatic control line and does not rely on flexible membranes and mechanical or moving parts. The presented bubble pump is therefore compatible with both elastomeric and rigid substrate materials and the associated scalable manufacturing processes. Directed liquid flow was achieved in a microchannel by an in-series configuration of two previously described "bubble gates", i.e., by gas-bubble enabled miniature gate valves. Only one time-dependent pressure signal is required and initiates at the upstream (active) bubble gate a reciprocating bubble motion. Applied at the downstream (passive) gate a time-constant gas pressure level is applied. In its rest state, the passive gate remains closed and only temporarily opens while the liquid pressure rises due to the active gate's reciprocating bubble motion. We have designed, fabricated and consistently operated our bubble pump with a variety of working liquids for >72 hours. Flow rates of 0-5.5 μl min(-1), were obtained and depended on the selected geometric dimensions, working fluids and actuation frequencies. The maximum operational pressure was 2.9 kPa-9.1 kPa and depended on the interfacial tension of the working fluids. Attainable flow rates compared favorably with those of available micropumps. We achieved flow rate enhancements of 30-100% by operating two bubble pumps in tandem and demonstrated scalability of the concept in a multi-well format with 12 individually and uniformly perfused microchannels (variation in flow rate <7%). We envision the demonstrated concept to allow for the consistent on-chip delivery of a wide range of different liquids that may even include highly reactive or moisture sensitive solutions. The presented bubble pump may provide active flow control for analytical and point-of-care diagnostic devices, as well as for microfluidic cells culture and organ-on-chip platforms.

Highly efficient broadband terahertz generation from ultrashort laser filamentation in liquids.

PubMed

Dey, Indranuj; Jana, Kamalesh; Fedorov, Vladimir Yu; Koulouklidis, Anastasios D; Mondal, Angana; Shaikh, Moniruzzaman; Sarkar, Deep; Lad, Amit D; Tzortzakis, Stelios; Couairon, Arnaud; Kumar, G Ravindra

2017-10-30

Generation and application of energetic, broadband terahertz pulses (bandwidth ~0.1-50 THz) is an active and contemporary area of research. The main thrust is toward the development of efficient sources with minimum complexities-a true table-top setup. In this work, we demonstrate the generation of terahertz radiation via ultrashort pulse induced filamentation in liquids-a counterintuitive observation due to their large absorption coefficient in the terahertz regime. The generated terahertz energy is more than an order of magnitude higher than that obtained from the two-color filamentation of air (the most standard table-top technique). Such high terahertz energies would generate electric fields of the order of MV cm -1 , which opens the doors for various nonlinear terahertz spectroscopic applications. The counterintuitive phenomenon has been explained via the solution of nonlinear pulse propagation equation in the liquid medium.

Biodiesel production using alkaline ionic liquid and adopted as lubricity additive for low-sulfur diesel fuel.

PubMed

Luo, Hui; Fan, Weiyu; Li, Yang; Nan, Guozhi

2013-07-01

Preparation of biodiesel from vegetable oils, such as rapeseed oil, soybean oil and sunflower oil, catalyzed by an alkaline ionic liquid 1-butyl-3-methylimidazolium imidazolide ([Bmim]Im) was investigated in this work. The results demonstrated that [Bmim]Im exhibited high activity and the yield of biodiesel was up to 95% or more when molar ratio of methanol to vegetable oil was 6:1, ionic liquid dosage was 6 wt.%, reaction temperature was 60°C, and reaction time was 60 min. After [Bmim]Im was used for the sixth time, the yield of biodiesel still remained at about 95%. The effects of the biodiesels on the lubricity of low-sulfur diesel fuel were also investigated using the High Frequency Reciprocating Rig method, and the results showed that sunflower biodiesel and soybean biodiesel had higher lubrication performance than that of rapeseed biodiesel. Copyright © 2012 Elsevier Ltd. All rights reserved.

Efficient removal of tetracycline with KOH-activated graphene from aqueous solution

PubMed Central

Sun, Yiran; Yu, Fei

2017-01-01

Activated graphene absorbents with high specific surface area (SSA) were prepared by an easy KOH-activated method, and were applied in absorbing antibiotics, such as tetracycline (TC). After activation, many micropores were introduced to graphene oxide sheets, leading to higher SSA and many new oxygen-containing functional groups, which gave KOH-activated graphene excellent adsorption capacity (approx. 532.59 mg g−1) of TC. Further study on the adsorption mechanism showed that the Langmuir isotherm model and the pseudo-second-order kinetic model fitted with experiment data. To further understand the adsorption process, the effects of solid–liquid ratio, pH, ionic strength and coexisting ions were also investigated. The results revealed that, compared with pH and ionic strength, solid–liquid ratio and coexisting ions (Cu2+, CrO42−) had more significant influence over the adsorption performance. The findings provide guidance for application of KOH-activated graphene as a promising alternative adsorbent for antibiotics removal from aqueous solutions. PMID:29291064

Rapid screening, separation, and detection of hydroxyl radical scavengers from total flavonoids of Ginkgo biloba leaves by chromatography combined with molecular devices.

PubMed

Wang, Jing; Zheng, Meizhu; Chen, Lina; Liu, Zhiqiang; Zhang, Yuchi; Liu, Chun-Ming; Liu, Shu

2016-11-01

Hydroxyl radicals are the most reactive free radical of human body, a strong contributor to tissue damage. In this study, liquid chromatography coupled to electrospray ionization mass spectrometry was applied to screen and identify hydroxyl radical scavengers from the total flavonoids of Ginkgo biloba leaves, and high-performance counter current chromatography was used to separate and isolate the active compounds. Furthermore, molecular devices were used to determine hydroxyl radical scavenging activities of the obtained hydroxyl radical scavengers and other flavonoids from G. biloba leaves. As a result, six compounds were screened as hydroxyl radical scavengers, but only three flavonoids, namely, rutin, cosmos glycosides and apigenin-7-O-Glu-4'-O-Rha, were isolated successfully from total flavonoids by high-performance counter current chromatography. The purities of the three obtained compounds were over 90%, respectively, as determined by liquid chromatography. Molecular devices with 96-well microplates evaluation indicated that the 50% scavenging concentration values of screened compounds were lower than that of other flavonoids, they performed greater hydroxyl radical scavenging activity, and the evaluation effects were consistent with the liquid chromatography with mass spectrometry screening results. Therefore, chromatography combined with molecular devices is a feasible and an efficient method for systematic screening, identification, isolation, and evaluation of bioactive components in mixture of botanical medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxidative desulfurization of model diesel via dual activation by a protic ionic liquid.

PubMed

Lü, Hongying; Wang, Shunan; Deng, Changliang; Ren, Wanzhong; Guo, Baocun

2014-08-30

A novel and green carboxylate-anion-based protic ionic liquid (PIL), [Hnmp]HCOO, was prepared through a simple and atom economic neutralization reaction between N-methyl-2-pyrrolidonium (NMP) and formic acids. Both FT-IR spectra and (1)H NMR confirmed its simple salt structure. [Hnmp]HCOO exhibited so high catalytic activity that the dibenzothiophene (DBT) removal reached 99% at 50°C in 3h under conditions of VPIL/Vmodel oil=1:10 and H2O2/DBT (O/S, molar ratio)=5. The catalytic oxidation reactivity of S-compounds was found to be in the order of DBT>4,6-dimethyldibenzothiophene (4,6-DMDBT)>benzothiophene (BT). The investigation on mechanism showed that oxidative desulfurization was realized through dual activation of PIL. Moreover, [Hnmp]HCOO can be recycled for five times with an unnoticeable decrease in desulfurization activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Liquid crystal mediated active nano-plasmonic based on the formation of hybrid plasmonic-photonic modes

NASA Astrophysics Data System (ADS)

Mehrzad, Hossein; Mohajerani, Ezeddin

2018-02-01

The present study aims to demonstrate how active hybrid nano-plasmonic modes become excited due to the coupling of localized plasmonic resonance and Fabry-Perot (FP) optical modes. The proposed structure includes an integration of a micro-cavity filled with liquid crystals with high anisotropy and a layer of gold nanoislands (NIs). The optical absorption of NI is controllably discretized to the narrow-width modes, called "hybrid modes (HM)," due to the interplay between FP and plasmonic modes. HM could demonstrate a strongly intensified and diminished absorption, compared to the absorption of the bare gold layer. Based on the active plasmonic experiments, the HM boosted the figure of merit related to activation capability up to 40 times and subsequently experienced impressive spectral shifts, leading to very wavelength-selective changes. The theoretical simulation of the HM is provided to suggest relevant insights into the experimental results.

Application of liquid-liquid-liquid microextraction and high-performance liquid chromatography for the determination of alkylphenols and bisphenol-A in water.

PubMed

Lin, Che-Yi; Fuh, Ming-Ren; Huang, Shang-Da

2011-02-01

A method termed liquid-liquid-liquid microextraction (LLLME) was utilized to extract 4-t-butylphenol, 4-t-octylphenol, 4-n-nonylphenol, and bisphenol-A from water. The extracted target analytes were separated and quantified by high-performance liquid chromatography using a fluorescence detector. In LLLME, the donor phase (i.e. water sample) was made weakly acidic by adding monobasic potassium phosphate (KH(2) PO(4)); the organic phase adopted was 4-chlorotoluene; the acceptor phase (i.e. enriched extract) was 0.2 M tetraethylammonium hydroxide dissolved in ethylene glycol. This study solves a problem associated with the surface activity of long-chain alkylphenolate ions, permitting LLLME to extract long-chain alkylphenols. Experimental conditions such as acceptor phase composition, organic phase identity, acceptor phase volume, sample agitation, extraction time, and salt addition were optimized. The relative standard deviation (RSD, 2.0-5.8%), coefficient of determination (r(2) 0.9977-0.9999), and detection limit (0.017-0.0048 ng/mL) of the proposed method were achieved under the selected optimized conditions. The method was successfully applied to analyses of lake and tap water samples, and the relative recoveries of target analytes from the spiked lake and tap water samples were 92.8-106.3 and 93.6-105.6%, respectively. The results obtained with the proposed method confirm this microextraction technique to be reliable for the monitoring of alkylphenols and bisphenol-A in water samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of blood concentrations of main active compounds in Zi-Cao-Cheng-Qi decoction and their total plasma protein binding rates based on hollow fiber liquid phase microextraction coupled with high performance liquid chromatography.

PubMed

Li, Miaomiao; Chen, Xuan; Hu, Shuang; Wang, Runqin; Peng, Xiaoli; Bai, Xiaohong

2018-01-01

Oil-in-salt hollow fiber liquid phase microextraction coupled with high performance liquid chromatography ultraviolet detection (HPLC-UV) was developed for determination of the blood concentrations of the main active compounds, hesperidin, honokiol, shikonin, magnolol, emodin and β,β'-dimethylacrylshikonin, after oral administration of Zi-Cao-Cheng-Qi decoction (ZCCQD) and their total plasma protein binding rates. In the procedure, a hollow fiber segment was immersed in organic solvent to fill the solvent in the fiber lumen and wall pore, and then the fiber was immersed into sodium chloride solution to cover a thin salt membrane on the fiber wall pore filling organic solvent. Various factors affecting the procedure, such as extraction solvent, sample phase pH, stirring rate, extraction time, NaCl concentration and fiber immersion time in the NaCl solution, were optimized. Under the optimum conditions, good linearities (r 2 ≥0.9905), low limits of detection (0.7-2.5ng/mL) or quantitation (1.2-12ng/mL), satisfactory precision (2.6%-12.8%) and accuracy (81.0%-114.2%) of this method, were observed. The results showed that, after oral administration of a 25g/kg dose, (1) the blood concentrations (at 0.5h) of hesperidin, honokiol, shikonin, magnolol, emodin and β,β'-dimethylacrylshikonin were 0.45, 0.40, 0.48, 0.74, 0.11 and 1.11μg/mL, respectively; (2) the total plasma protein binding rates of the six active compounds were 42.0% (hesperidin), 71.8% (honokiol), 64.6% (shikonin), 77.7% (magnolol), 75.3% (emodin) and 75.7% (β,β'-dimethylacrylshikonin), respectively. The proposed procedure coupled with HPLC shows obvious advantages, such as low solvent consumption, simple operation, high sensitivity and strong purifying and can be used for the determination of both the blood concentrations and total plasma protein binding rates of active compounds in traditional Chinese medicine. Copyright © 2017 Elsevier B.V. All rights reserved.

High Performance Liquid Chromatography-mass Spectrometry Analysis of High Antioxidant Australian Fruits with Antiproliferative Activity Against Cancer Cells

PubMed Central

Sirdaarta, Joseph; Maen, Anton; Rayan, Paran; Matthews, Ben; Cock, Ian Edwin

2016-01-01

Background: High antioxidant capacities have been linked to the treatment and prevention of several cancers. Recent reports have identified several native Australian fruits with high antioxidant capacities. Despite this, several of these species are yet to be tested for anticancer activity. Materials and Methods: Solvent extracts prepared from high antioxidant native Australian fruits were analyzed for antioxidant capacity by the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium free radical scavenging assay. Antiproliferative activities against CaCo2 and HeLa cancer cells were determined by a multicellular tumor spheroid-based cell proliferation assay. Toxicity was determined by Artemia franciscana bioassay. Results: Methanolic extracts of all plant species displayed high antioxidant contents (equivalent to approximately 7–16 mg of vitamin C per gram of fruit extracted). Most aqueous extracts also contained relatively high antioxidant capacities. In contrast, the ethyl acetate, chloroform, and hexane extracts of most species (except lemon aspen and bush tomato) had lower antioxidant contents (below 1.5 mg of vitamin C equivalents per gram of plant material extracted). The antioxidant contents correlated with the ability of the extracts to inhibit proliferation of CaCo2 and HeLa cancer cell lines. The high antioxidant methanolic extracts of all species were potent inhibitors of cell proliferation. The methanolic lemon aspen extract was particularly effective, with IC50 values of 480 and 769 μg/mL against HeLa and CaCo2 cells, respectively. In contrast, the lower antioxidant ethyl acetate and hexane extracts (except the lemon aspen ethyl acetate extract) generally did not inhibit cancer cell proliferation or inhibited to only a minor degree. Indeed, most of the ethyl acetate and hexane extracts induced potent cell proliferation. The native tamarind ethyl acetate extract displayed low-moderate toxicity in the A. franciscana bioassay (LC50 values below 1000 μg/mL). All other extracts were nontoxic. A total of 145 unique mass signals were detected in the lemon aspen methanolic and aqueous extracts by nonbiased high-performance liquid chromatography-mass spectrometry analysis. Of these, 20 compounds were identified as being of particular interest due to their reported antioxidant and/or anticancer activities. Conclusions: The lack of toxicity and antiproliferative activity of the high antioxidant plant extracts against HeLa and CaCo2 cancer cell lines indicates their potential in the treatment and prevention of some cancers. SUMMARY Australian fruit extracts with high antioxidant contents were potent inhibitors of CaCo2 and HeLa carcinoma cell proliferationMethanolic lemon aspen extract was particularly potent, with IC50 values of 480 μg/mL (HeLa) and 769 μg/mL (CaCo2)High-performance liquid chromatography-mass spectrometry-quadrupole time-of-flight analysis highlighted and putatively identified 20 compounds in the antiproliferative lemon aspen extractsIn contrast, lower antioxidant content extracts stimulated carcinoma cell proliferationAll extracts with antiproliferative activity were nontoxic in the Artemia nauplii assay. Abbreviations used: DPPH: di (phenyl)- (2,4,6-trinitrophenyl) iminoazanium, HPLC: High-performance liquid chromatography, IC50: The concentration required to inhibit by 50%, LC50: The concentration required to achieve 50% mortality, MS: Mass spectrometry. PMID:27279705

Excimer Formation Dynamics of Dipyrenyldecane in Structurally Different Ionic Liquids.

PubMed

Yadav, Anita; Pandey, Siddharth

2017-12-07

Ionic liquids, being composed of ions alone, may offer alternative pathways for molecular aggregation. These pathways could be controlled by the chemical structure of the cation and the anion of the ionic liquids. Intramolecular excimer formation dynamics of a bifluorophoric probe, 1,3-bis(1-pyrenyl)decane [1Py(10)1Py], where the fluorophoric pyrene moieties are separated by a long decyl chain, is investigated in seven different ionic liquids in 10-90 °C temperature range. The long alkyl separator allows for ample interaction with the solubilizing milieu prior to the formation of the excimer. The ionic liquids are composed of two sets, one having four ionic liquids of 1-butyl-3-methylimidazolium cation ([bmim + ]) with different anions and the other having four ionic liquids of bis(trifluoromethylsulfonyl)imide anion ([Tf 2 N - ]) with different cations. The excimer-to-monomer emission intensity ratio (I E /I M ) is found to increase with increasing temperature in sigmoidal fashion. Chemical structure of the ionic liquid controls the excimer formation efficiency, as I E /I M values within ionic liquids with the same viscosities are found to be significantly different. The excited-state intensity decay kinetics of 1Py(10)1Py in ionic liquids do not adhere to a simplistic Birk's scheme, where only one excimer conformer forms after excitation. The apparent rate constants of excimer formation (k a ) in highly viscous ionic liquids are an order of magnitude lower than those reported in organic solvents. In general, the higher the viscosity of the ionic liquid, the more sensitive is the k a to the temperature with higher activation energy, E a . The trend in E a is found to be similar to that for activation energy of the viscous flow (E a,η ). Stokes-Einstein relationship is not followed in [bmim + ] ionic liquids; however, with the exception of [choline][Tf 2 N], it is found to be followed in [Tf 2 N - ] ionic liquids suggesting the cyclization dynamics of 1Py(10)1Py to be diffusion-controlled and to depend on the viscosity of the ionic liquid irrespective of the identity of the cation. The dependence of ionic liquid structure on cyclization dynamics to form intramolecular excimer is amply highlighted.

All-solid-state flexible supercapacitors based on papers coated with carbon nanotubes and ionic-liquid-based gel electrolytes.

PubMed

Kang, Yu Jin; Chung, Haegeun; Han, Chi-Hwan; Kim, Woong

2012-02-17

All-solid-state flexible supercapacitors were fabricated using carbon nanotubes (CNTs), regular office papers, and ionic-liquid-based gel electrolytes. Flexible electrodes were made by coating CNTs on office papers by a drop-dry method. The gel electrolyte was prepared by mixing fumed silica nanopowders with ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf(2)]). This supercapacitor showed high power and energy performance as a solid-state flexible supercapacitor. The specific capacitance of the CNT electrodes was 135 F g(-1) at a current density of 2 A g(-1), when considering the mass of active materials only. The maximum power and energy density of the supercapacitors were 164 kW kg(-1) and 41 Wh kg(-1), respectively. Interestingly, the solid-state supercapacitor with the gel electrolyte showed comparable performance to the supercapacitors with ionic-liquid electrolyte. Moreover, the supercapacitor showed excellent stability and flexibility. The CNT/paper- and gel-based supercapacitors may hold great potential for low-cost and high-performance flexible energy storage applications.

All-solid-state flexible supercapacitors based on papers coated with carbon nanotubes and ionic-liquid-based gel electrolytes

NASA Astrophysics Data System (ADS)

Kang, Yu Jin; Chung, Haegeun; Han, Chi-Hwan; Kim, Woong

2012-02-01

All-solid-state flexible supercapacitors were fabricated using carbon nanotubes (CNTs), regular office papers, and ionic-liquid-based gel electrolytes. Flexible electrodes were made by coating CNTs on office papers by a drop-dry method. The gel electrolyte was prepared by mixing fumed silica nanopowders with ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]). This supercapacitor showed high power and energy performance as a solid-state flexible supercapacitor. The specific capacitance of the CNT electrodes was 135 F g-1 at a current density of 2 A g-1, when considering the mass of active materials only. The maximum power and energy density of the supercapacitors were 164 kW kg-1 and 41 Wh kg-1, respectively. Interestingly, the solid-state supercapacitor with the gel electrolyte showed comparable performance to the supercapacitors with ionic-liquid electrolyte. Moreover, the supercapacitor showed excellent stability and flexibility. The CNT/paper- and gel-based supercapacitors may hold great potential for low-cost and high-performance flexible energy storage applications.

Highly Swellable, Dual-Responsive Hydrogels Based on PNIPAM and Redox Active Poly(ferrocenylsilane) Poly(ionic liquid)s: Synthesis, Structure, and Properties.

PubMed

Feng, Xueling; Zhang, Kaihuan; Chen, Peng; Sui, Xiaofeng; Hempenius, Mark A; Liedberg, Bo; Vancso, G Julius

2016-12-01

Highly swellable, dual-responsive hydrogels, consisting of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) and redox-responsive poly(ferrocenylsilane) (PFS) based poly(ionic liquid)s (PILs) are formed by photo-polymerization. PFS chains bearing cross-linkable vinylimidazolium (VIm) side groups are copolymerized with NIPAM in aqueous solutions under ultraviolet light (λ = 365 nm) in the presence of a photoinitiator. The PFS-PILs serve as a macro-cross-linker and also provide redox responsiveness. The swelling ratio, morphology, and lower critical solution temperature (LCST) of the hydrogels are studied as a function of the PNIPAM/PFS ratio. The value of the LCST is dependent on the choice of the counterion of the PIL and the PNIPAM/PFS ratio. The hydrogel is employed as a reducing environment for the in situ fabrication of gold nanoparticles (AuNPs), forming AuNP-hydrogel composites. The localized surface plasmon resonance peak of the as-synthesized Au nanoparticles inside the hydrogel could be tuned by altering the temperature. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of Nanomaterials by the Pulsed Plasma in Liquid and their Bio-medical Applications

NASA Astrophysics Data System (ADS)

Omurzak, E.; Abdullaeva, Z.; Satyvaldiev, A.; Zhasnakunov, Z.; Kelgenbaeva, Z.; Akai Tegin, R. Adil; Syrgakbek kyzy, D.; Doolotkeldieva, T.; Bobusheva, S.; Mashimo, T.

2018-01-01

Pulsed plasma in liquid is a simple, ecologically friendly, cost-efficient method based on electrical discharge between two metal electrodes submerged into a dielectric liquid. We synthesized carbon-encapsulated Fe (Fe@C) magnetic nanoparticles with low cytotoxicity using pulsed plasma in a liquid. Body-centered cubic Fe core nanoparticles showed good crystalline structures with an average size between 20 and 30 nm were encapsulated in onion-like carbon coatings with a thickness of 2-10 nm. Thermal gravimetric analysis showed a high stability of the as-synthesized samples under thermal treatment and oxidation. Cytotoxicity measurements showed higher cancer cell viability than samples synthesized by different methods. Carbon coated ZnO nanorods with about 20 nm thickness and 150 nm length were synthesized by this method using different surfactant materials such as cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS). Cu and Ag nanoparticles of about 10 nm in size were also synthesized by the pulsed plasma in aquatic solution of 0.2 % gelatine as surfactant material. These nanoparticles showed high antibacterial activity for Erwinia amylovora and Escherichia coli.

Transmitted spectral modulation of double-ring resonator using liquid crystals in terahertz range

NASA Astrophysics Data System (ADS)

Sun, Huijuan; Zhou, Qingli; Wang, Xiumin; Li, Chenyu; Wu, Ani; Zhang, Cunlin

2013-12-01

Metamaterials with subwavelength structural features show unique electromagnetic responses that are unattainable with natural materials. Recent research on these artificial materials has been pushed forward to the terahertz region because of potential applications in biological fingerprinting, security imaging, remote sensing, and high frequency magnetic and electric resonant devices. Active control of their properties could further facilitate and open up new applications in terms of modulation and switching. Liquid crystals, which have been the subject of research for more than a century, have the unique properties for the development of many other optical components such as light valves, tunable filters and tunable lenses. In this paper, we investigated the transmitted spectral modulation in terahertz range by using liquid crystals (5CB and TEB300) covering on the fabricated double-ring resonators to realize the shift of the resonance frequency. Our obtained results indicate the low frequency resonance shows the obvious blue-shift, while the location of high frequency resonance is nearly unchanged. We believe this phenomenon is related to not only the refractive index of the covering liquid crystals but also the resonant mechanism of both resonances.

Ultrathin Au-Alloy Nanowires at the Liquid-Liquid Interface.

PubMed

Chatterjee, Dipanwita; Shetty, Shwetha; Müller-Caspary, Knut; Grieb, Tim; Krause, Florian F; Schowalter, Marco; Rosenauer, Andreas; Ravishankar, Narayanan

2018-03-14

Ultrathin bimetallic nanowires are of importance and interest for applications in electronic devices such as sensors and heterogeneous catalysts. In this work, we have designed a new, highly reproducible and generalized wet chemical method to synthesize uniform and monodispersed Au-based alloy (AuCu, AuPd, and AuPt) nanowires with tunable composition using microwave-assisted reduction at the liquid-liquid interface. These ultrathin alloy nanowires are below 4 nm in diameter and about 2 μm long. Detailed microstructural characterization shows that the wires have an face centred cubic (FCC) crystal structure, and they have low-energy twin-boundary and stacking-fault defects along the growth direction. The wires exhibit remarkable thermal and mechanical stability that is critical for important applications. The alloy wires exhibit excellent electrocatalytic activity for methanol oxidation in an alkaline medium.

Large underground, liquid based detectors for astro-particle physics in Europe: scientific case and prospects

NASA Astrophysics Data System (ADS)

Autiero, D.; Äystö, J.; Badertscher, A.; Bezrukov, L.; Bouchez, J.; Bueno, A.; Busto, J.; Campagne, J.-E.; Cavata, Ch; Chaussard, L.; de Bellefon, A.; Déclais, Y.; Dumarchez, J.; Ebert, J.; Enqvist, T.; Ereditato, A.; von Feilitzsch, F.; Fileviez Perez, P.; Göger-Neff, M.; Gninenko, S.; Gruber, W.; Hagner, C.; Hess, M.; Hochmuth, K. A.; Kisiel, J.; Knecht, L.; Kreslo, I.; Kudryavtsev, V. A.; Kuusiniemi, P.; Lachenmaier, T.; Laffranchi, M.; Lefievre, B.; Lightfoot, P. K.; Lindner, M.; Maalampi, J.; Maltoni, M.; Marchionni, A.; Marrodán Undagoitia, T.; Marteau, J.; Meregaglia, A.; Messina, M.; Mezzetto, M.; Mirizzi, A.; Mosca, L.; Moser, U.; Müller, A.; Natterer, G.; Oberauer, L.; Otiougova, P.; Patzak, T.; Peltoniemi, J.; Potzel, W.; Pistillo, C.; Raffelt, G. G.; Rondio, E.; Roos, M.; Rossi, B.; Rubbia, A.; Savvinov, N.; Schwetz, T.; Sobczyk, J.; Spooner, N. J. C.; Stefan, D.; Tonazzo, A.; Trzaska, W.; Ulbricht, J.; Volpe, C.; Winter, J.; Wurm, M.; Zalewska, A.; Zimmermann, R.

2007-11-01

This document reports on a series of experimental and theoretical studies conducted to assess the astro-particle physics potential of three future large scale particle detectors proposed in Europe as next generation underground observatories. The proposed apparatuses employ three different and, to some extent, complementary detection techniques: GLACIER (liquid argon TPC), LENA (liquid scintillator) and MEMPHYS (water Cherenkov), based on the use of large mass of liquids as active detection media. The results of these studies are presented along with a critical discussion of the performance attainable by the three proposed approaches coupled to existing or planned underground laboratories, in relation to open and outstanding physics issues such as the search for matter instability, the detection of astrophysical neutrinos and geo-neutrinos and to the possible use of these detectors in future high intensity neutrino beams.

Certification Process for Commercial Batteries for Payloads

NASA Technical Reports Server (NTRS)

Jeevarajan, Judith

2007-01-01

This viewgraph document reviews the use of electric batteries in space applications. Batteries are high energy devices that are used to power hardware for space applications The applications include IVA (Intra-Vehicular Activity) and EVA (Extra-Vehicular Activity) use. High energy batteries pose hazards such as cell/battery venting leading to electrolyte (liquid or gas) leakage, high temperatures, fire and explosion (shrapnel). It reviews the process of certifying of Commercial batteries for space applications in view of the multi-national purchasing for the International Space Station. The documentation used in the certification is reviewed.

Liquid and Gaseous Waste Operations Department annual operating report CY 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maddox, J.J.; Scott, C.B.

1997-03-01

This annual report summarizes operating activities dealing with the process waste system, the liquid low-level waste system, and the gaseous waste system. It also describes upgrade activities dealing with the process and liquid low-level waste systems, the cathodic protection system, a stack ventilation system, and configuration control. Maintenance activities are described dealing with nonradiological wastewater treatment plant, process waste treatment plant and collection system, liquid low-level waste system, and gaseous waste system. Miscellaneous activities include training, audits/reviews/tours, and environmental restoration support.

Generation and remote delivery of plasma activated species

NASA Astrophysics Data System (ADS)

Maguire, Paul; Mahony, Charles; Kelsey, Colin; Rutherford, David; Mariotti, Davide; Macias-Montero, Manuel; Perez-Martin, Fatima; Diver, Declan

2016-09-01

Plasma interactions with microdroplets offer new opportunities to deliver active chemical agents and nanoparticles to remote substrates downstream with many potential applications from cancer theranostics and wound healing in biomedicine, gentle food decontamination and seed germination in plasma agriculture to catalyst production and photonic structures fabrication, among others. We demonstrate plasma-liquid based pristine nanomaterials synthesis in flight and subsequent delivery up to 120mm from the atmospheric pressure plasma source. Monosized and non-aggregating metal nanoparticles are formed in the rf plasma in less than 100us, representing an increase in precursor reduction rate that is many (>4) orders of magnitude faster than that observed with standard colloidal chemistry or via high energy radiolytic techniques. Also the collection and purification limitations of the latter are avoided. Plasma activated liquid including OH radicals and H2O2 are transported over 120mm and have demonstrated high efficacy bacterial decontamination. These results will be compared with charge species and radical transport from the rf plasma without microdroplets. Reaction models based on high solvated surface electron concentrations will be presented. Funding from EPSRC acknowledged (Grants EP/K006088/1 and EP/K006142/1).

[Study on the Emission Spectrum of Hydrogen Production with Microwave Discharge Plasma in Ethanol Solution].

PubMed

Sun, Bing; Wang, Bo; Zhu, Xiao-mei; Yan, Zhi-yu; Liu, Yong-jun; Liu, Hui

2016-03-01

Hydrogen is regarded as a kind of clean energy with high caloricity and non-pollution, which has been studied by many experts and scholars home and abroad. Microwave discharge plasma shows light future in the area of hydrogen production from ethanol solution, providing a new way to produce hydrogen. In order to further improve the technology and analyze the mechanism of hydrogen production with microwave discharge in liquid, emission spectrum of hydrogen production by microwave discharge plasma in ethanol solution was being studied. In this paper, plasma was generated on the top of electrode by 2.45 GHz microwave, and the spectral characteristics of hydrogen production from ethanol by microwave discharge in liquid were being studied using emission spectrometer. The results showed that a large number of H, O, OH, CH, C2 and other active particles could be produced in the process of hydrogen production from ethanol by microwave discharge in liquid. The emission spectrum intensity of OH, H, O radicals generated from ethanol is far more than that generated from pure water. Bond of O-H split by more high-energy particles from water molecule was more difficult than that from ethanol molecule, so in the process of hydrogen production by microwave discharge plasma in ethanol solution; the main source of hydrogen was the dehydrogenation and restructuring of ethanol molecules instead of water decomposition. Under the definite external pressure and temperature, the emission spectrum intensity of OH, H, O radicals increased with the increase of microwave power markedly, but the emission spectrum intensity of CH, C2 active particles had the tendency to decrease with the increase of microwave power. It indicated that the number of high energy electrons and active particles high energy electron energy increased as the increase of microwave power, so more CH, C2 active particles were split more thoroughly.

New high-performance liquid chromatography assay for glycosyltransferases based on derivatization with anthranilic acid and fluorescence detection.

PubMed

Anumula, Kalyan Rao

2012-07-01

Assays were developed using the unique labeling chemistry of 2-aminobenzoic acid (2AA; anthranilic acid, AA) for measuring activities of both β1-4 galactosyltransferase (GalT-1) and α2-6 sialyltransferase (ST-6) by high-performance liquid chromatography (HPLC) with fluorescence detection (Anumula KR. 2006. Advances in fluorescence derivatization methods for high-performance liquid chromatographic analysis of glycoprotein carbohydrates. Anal Biochem. 350:1-23). N-Acetylglucosamine (GlcNAc) and N-acetyllactosamine were used as acceptors and uridine diphosphate (UDP)-galactose and cytidine monophosphate (CMP)-N-acetylneuraminic acid (NANA) as donors for GalT-1 and ST-6, respectively. Enzymatic products were labeled in situ with AA and were separated from the substrates on TSKgel Amide 80 column using normal-phase conditions. Enzyme units were determined from the peak areas by comparison with the concomitantly derivatized standards Gal-β1-4GlcNAc and NANA-α2-6 Gal-β1-4GlcNAc. Linearity (time and enzyme concentration), precision (intra- and interassay) and reproducibility for the assays were established. The assays were found to be useful in monitoring the enzyme activities during isolation and purification. The assays were highly sensitive and performed equal to or better than the traditional radioactive sugar-based measurements. The assay format can also be used for measuring the activity of other transferases, provided that the carbohydrate acceptors contain a reducing end for labeling. An assay for glycoprotein acceptors was developed using IgG. A short HPLC profiling method was developed for the separation of IgG glycans (biantennary G0, G1, G2, mono- and disialylated), which facilitated the determination of GalT-1 and ST-6 activities in a rapid manner. Furthermore, this profiling method should prove useful for monitoring the changes in IgG glycans in clinical settings.

DESIGN AND DEVELOPMENT OF GAS-LIQUID CYLINDRICAL CYCLONE COMPACT SEPARATORS FOR THREE-PHASE FLOW

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Ram S. Mohan; Dr. Ovadia Shoham

The U.S. Department of Energy (DOE) has awarded a five-year (1997-2002) grant (Mohan and Shoham, DE-FG26-97BC15024, 1997) to The University of Tulsa, to develop compact multiphase separation components for 3-phase flow. The research activities of this project have been conducted through cost sharing by the member companies of the Tulsa University Separation Technology Projects (TUSTP) research consortium and the Oklahoma Center for the Advancement of Science and Technology (OCAST). As part of this project, several individual compact separation components have been developed for onshore and offshore applications. These include gas-liquid cylindrical cyclones (GLCC{copyright}), liquid-liquid cylindrical cyclones (LLCC{copyright}), and the gas-liquid-liquidmore » cylindrical cyclones (GLLCC{copyright}). A detailed study has also been completed for the liquid-liquid hydrocyclones (LLHC). Appropriate control strategies have been developed for proper operation of the GLCC{copyright} and LLCC{copyright}. Testing of GLCC{copyright} at high pressure and real crude conditions for field applications is also completed. Limited studies have been conducted on flow conditioning devices to be used upstream of the compact separators for performance improvement. This report presents a brief overview of the activities and tasks accomplished during the 5-year project period, October 1, 1997-March 31, 2003 (including the no-cost extended period of 6 months). An executive summary is presented initially followed by the tasks of the 5-year budget periods. Then, detailed description of the experimental and modeling investigations are presented. Subsequently, the technical and scientific results of the activities of this project period are presented with some discussions. The findings of this investigation are summarized in the ''Conclusions'' section, followed by relevant references. The publications resulting from this study in the form of MS Theses, Ph.D. Dissertation, Journal Papers and Conference Presentations are provided at the end of this report.« less

Lactic acid bacteria as functional probiotic isolates for inhibiting the growth of Aspergillus flavus, A. parasiticus, A. niger and Penicillium chrysogenum.

PubMed

Abbaszadeh, S; Tavakoli, R; Sharifzadeh, A; Shokri, H

2015-12-01

The aim of this study was to assess the potential of lactic acid bacteria (LAB) such as Lactobacillus acidophilus, L. rhamnosus, L. casei, L. paracasei and Bifidobacterium bifidum to inhibit the outgrowth of some common food-spoiling fungi including Aspergillus niger, A. flavus, A. parasiticus and Penicillium chrysogenum. Bacterial isolates were cultured on Mann Rogosa Sharpe (MRS) broth and liquid cultures and supernatants were prepared. The antifungal activity was tested using the agar well diffusion method. Both liquid culture and supernatant of L. casei isolate exhibited high antifungal activity, followed by L. acidophilus and L. paracasei isolates. The least activity was recorded for the isolates B. bifidum, while the isolate L. rhamnosus was moderately active against tested fungi. The antifungal activity of the supernatants obtained from all probiotic isolates against fungi was significantly less than that of liquid cultures (P<0.05). Antifungal activity evaluation showed that A. flavus was the most inhibited fungus by probiotic bacteria, followed by P. chrysogenum, A. niger and A. parasiticus. These results suggest that probiotic bacteria strains have the ability to prevent the growth of pathogenic and mycotoxigenic fungi as antifungal agents for various biomedical applications. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Quality assessment of Herba Leonuri based on the analysis of multiple components using normal- and reversed-phase chromatographic methods.

PubMed

Dong, Shuya; He, Jiao; Hou, Huiping; Shuai, Yaping; Wang, Qi; Yang, Wenling; Sun, Zheng; Li, Qing; Bi, Kaishun; Liu, Ran

2017-12-01

A novel, improved, and comprehensive method for quality evaluation and discrimination of Herba Leonuri has been developed and validated based on normal- and reversed-phase chromatographic methods. To identify Herba Leonuri, normal- and reversed-phase high-performance thin-layer chromatography fingerprints were obtained by comparing the colors and R f values of the bands, and reversed-phase high-performance liquid chromatography fingerprints were obtained by using an Agilent Poroshell 120 SB-C18 within 28 min. By similarity analysis and hierarchical clustering analysis, we show that there are similar chromatographic patterns in Herba Leonuri samples, but significant differences in counterfeits and variants. To quantify the bio-active components of Herba Leonuri, reversed-phase high-performance liquid chromatography was performed to analyze syringate, leonurine, quercetin-3-O-robiniaglycoside, hyperoside, rutin, isoquercitrin, wogonin, and genkwanin simultaneously by single standard to determine multi-components method with rutin as internal standard. Meanwhile, normal-phase high-performance liquid chromatography was performed by using an Agilent ZORBAX HILIC Plus within 6 min to determine trigonelline and stachydrine using trigonelline as internal standard. Innovatively, among these compounds, bio-active components of quercetin-3-O-robiniaglycoside and trigonelline were first determined in Herba Leonuri. In general, the method integrating multi-chromatographic analyses offered an efficient way for the standardization and identification of Herba Leonuri. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Catalyst characterization in the presence of solvent: development of liquid phase structure–activity relationships

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gould, Nicholas S.; Xu, Bingjun

Due to the low volatility and highly oxygenated nature of biomass derived feedstocks, biomass upgrade reactions are frequently conducted in the presence of solvent to improve substrate mass transfer to the catalyst surface.

SYNTHESIZING ORGANIC COMPOUNDS USING LIGHT-ACTIVATED TIO2

EPA Science Inventory

High-value organic compounds have been synthesized successfully from linear and cyclic hydrocarbons, by photocatalytic oxidation using a semiconductor material, titanium dioxide (TiO2). Various hydrocarbons were partially oxgenated in both liquid and gaseous phase reactors usi...

Catalyst characterization in the presence of solvent: development of liquid phase structure–activity relationships

DOE PAGES

Gould, Nicholas S.; Xu, Bingjun

2018-01-01

Due to the low volatility and highly oxygenated nature of biomass derived feedstocks, biomass upgrade reactions are frequently conducted in the presence of solvent to improve substrate mass transfer to the catalyst surface.

Microwave irradiation for the facile synthesis of transition-metal nanoparticles (NPs) in ionic liquids (ILs) from metal-carbonyl precursors and Ru-, Rh-, and Ir-NP/IL dispersions as biphasic liquid-liquid hydrogenation nanocatalysts for cyclohexene.

PubMed

Vollmer, Christian; Redel, Engelbert; Abu-Shandi, Khalid; Thomann, Ralf; Manyar, Haresh; Hardacre, Christopher; Janiak, Christoph

2010-03-22

Stable chromium, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, and iridium metal nanoparticles (M-NPs) have been reproducibly obtained by facile, rapid (3 min), and energy-saving 10 W microwave irradiation (MWI) under an argon atmosphere from their metal-carbonyl precursors [M(x)(CO)(y)] in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF(4)]). This MWI synthesis is compared to UV-photolytic (1000 W, 15 min) or conventional thermal decomposition (180-250 degrees C, 6-12 h) of [M(x)(CO)(y)] in ILs. The MWI-obtained nanoparticles have a very small (<5 nm) and uniform size and are prepared without any additional stabilizers or capping molecules as long-term stable M-NP/IL dispersions (characterization by transmission electron microscopy (TEM), transmission electron diffraction (TED), and dynamic light scattering (DLS)). The ruthenium, rhodium, or iridium nanoparticle/IL dispersions are highly active and easily recyclable catalysts for the biphasic liquid-liquid hydrogenation of cyclohexene to cyclohexane with activities of up to 522 (mol product) (mol Ru)(-1) h(-1) and 884 (mol product) (mol Rh)(-1) h(-1) and give almost quantitative conversion within 2 h at 10 bar H(2) and 90 degrees C. Catalyst poisoning experiments with CS(2) (0.05 equiv per Ru) suggest a heterogeneous surface catalysis of Ru-NPs.

Highly stable noble-metal nanoparticles in tetraalkylphosphonium ionic liquids for in situ catalysis.

PubMed

Banerjee, Abhinandan; Theron, Robin; Scott, Robert W J

2012-01-09

Gold and palladium nanoparticles were prepared by lithium borohydride reduction of the metal salt precursors in tetraalkylphosphonium halide ionic liquids in the absence of any organic solvents or external nanoparticle stabilizers. These colloidal suspensions remained stable and showed no nanoparticle agglomeration over many months. A combination of electrostatic interactions between the coordinatively unsaturated metal nanoparticle surface and the ionic-liquid anions, bolstered by steric protection offered by the bulky alkylated phosphonium cations, is likely to be the reason behind such stabilization. The halide anion strongly absorbs to the nanoparticle surface, leading to exceptional nanoparticle stability in halide ionic liquids; other tetraalkylphosphonium ionic liquids with non-coordinating anions, such as tosylate and hexafluorophosphate, show considerably lower affinities towards the stabilization of nanoparticles. Palladium nanoparticles stabilized in the tetraalkylphosphonium halide ionic liquid were stable, efficient, and recyclable catalysts for a variety of hydrogenation reactions at ambient pressures with sustained activity. Aerial oxidation of the metal nanoparticles occurred over time and was readily reversed by re-reduction of oxidized metal salts. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Upgraded Readout Electronics for the ATLAS Liquid Argon Calorimeters at the High Luminosity LHC

NASA Astrophysics Data System (ADS)

Andeen, Timothy R.; ATLAS Liquid Argon Calorimeter Group

2012-12-01

The ATLAS liquid-argon calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics sum analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up background expected during the high luminosity phases of the LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons or photons, at high background rejection rates. For the first upgrade phase in 2018, new Liquid Argon Trigger Digitizer Boards are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new, off-detector digital processing system. The digital processing system applies digital filtering and identifies significant energy depositions. The refined trigger primitives are then transmitted to the first level trigger system to extract improved trigger signatures. The general concept of the upgraded liquid-argon calorimeter readout together with the various electronics components to be developed for such a complex system is presented. The research activities and architectural studies undertaken by the ATLAS Liquid Argon Calorimeter Group are described, particularly details of the on-going design of mixed-signal front-end electronics, of radiation tolerant optical-links, and of the high-speed off-detector digital processing system.

Isolation and identification of phenolic compounds from rum aged in oak barrels by high-speed countercurrent chromatography/high-performance liquid chromatography-diode array detection-electrospray ionization mass spectrometry and screening for antioxidant activity.

PubMed

Regalado, Erik L; Tolle, Sebastian; Pino, Jorge A; Winterhalter, Peter; Menendez, Roberto; Morales, Ana R; Rodríguez, José L

2011-10-14

Beverages, especially wines are well-known to contain a variety of health-beneficial bioactive substances, mainly of phenolic nature which frequently exhibit antioxidant activity. Significant information is available about the separation and identification of polyphenols from some beverages by chromatographic and spectroscopic techniques, but considerably poor is chemical data related to the polyphenolic content in rums. In this paper, a method involving the all-liquid chromatographic technique of high-speed countercurrent chromatography (HSCCC) combined with high-performance liquid chromatography coupled with diode-array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS(n)) has been successfully applied for separation and identification of phenolic compounds in an aged rum. Besides, the phenolic fraction (PF) was assayed for its antioxidant effects using three different free radical in vitro assays (DPPH·, RO(2)· and spontaneous lipid peroxidation (LPO) on brain homogenates) and on ferric reducing antioxidant power (FRAP). Results showed that PF potently scavenged DPPH and strongly scavenged peroxyl radicals compared to ascorbic acid and butylated hydroxytoluene (BHT); and almost equally inhibited LPO on brain homogenates subjected to spontaneous LPO when compared to quercetin. Moreover, PF also exhibited strong reducing power. This chemical analysis illustrates the rich array of phenols in the aged rum and represents a rapid and suitable method for the isolation and identification of phenolic compounds from mixtures of considerable complexity, achieving high purity and reproducibility with the use of two separation steps. Copyright © 2011 Elsevier B.V. All rights reserved.

Screening anti-tumor compounds from Ligusticum wallichii using cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry.

PubMed

Zhang, Tao; Ding, Yuanyuan; An, Hongli; Feng, Liuxin; Wang, Sicen

2015-07-14

Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry was developed. Tyrosine 367 Cysteine-HEK293 cells were used as cell membrane stationary phase. Specificity and reproducibility of the cell membrane chromatography was evaluated using 1-tert-butyl-3-{2-[4-(diethylamino)butylamino]-6-(3,5-dimethoxyphenyl)pyrido[2,3-d]pyrimidin-7-yl}urea, Nimodipine and dexamethasone acetate. Then, anti-tumor components acting on Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 were screened and identified from extracts of Ligusticum wallichii. Components from the extract were retained on the cell membrane chromatographic column. The retained fraction was directly eluted into high-performance liquid chromatography with mass spectrometry system for separation and identification. Finally, Levistolide A was identified as an active component from Ligusticum wallichii extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan colorimetric assay revealed that Levistolide A inhibits proliferation of overexpressing the mutated receptor cells with dose-dependent manner. Phosphorylation of fibroblast growth factor receptor 4 was also decrease under Levistolide A treatment. Flex dock simulation verified that Levistolide A could bind with the tyrosine kinase domain of fibroblast growth factor receptor 4. Therefore, Levistolide A screened by the cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry can arrest cell growth. In conclusion, the two-dimensional high-performance liquid chromatography method can screen and identify potential anti-tumor ingredients which specifically act on the tyrosine kinase domain of the mutated fibroblast growth factor receptor 4. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The NASA Icing Remote Sensing System

NASA Technical Reports Server (NTRS)

Reehorst, Andrew L.; Brinker, David J.; Ratvasky, Thomas P.; Ryerson, Charles C.; Koenig, George G.

2005-01-01

NASA and the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) have an on-going activity to develop remote sensing technologies for the detection and measurement of icing conditions aloft. A multiple instrument approach is the current emphasis of this activity. Utilizing radar, radiometry, and lidar, a region of supercooled liquid is identified. If the liquid water content (LWC) is sufficiently high, then the region of supercooled liquid cloud is flagged as being an aviation hazard. The instruments utilized for the current effort are an X-band vertical staring radar, a radiometer that measures twelve frequencies between 22 and 59 GHz, and a lidar ceilometer. The radar data determine cloud boundaries, the radiometer determines the sub-freezing temperature heights and total liquid water content, and the ceilometer refines the lower cloud boundary. Data are post-processed with a LabVIEW program with a resultant supercooled LWC profile and aircraft hazard identification. Remotely sensed measurements gathered during the 2003-2004 Alliance Icing Research Study (AIRS II) were compared to aircraft in-situ measurements. Although the comparison data set is quite small, the cases examined indicate that the remote sensing technique appears to be an acceptable approach.

In Vitro Cultivars of Vaccinium corymbosum L. (Ericaceae) are a Source of Antioxidant Phenolics.

PubMed

Contreras, Rodrigo A; Köhler, Hans; Pizarro, Marisol; Zúiga, Gustavo E

2015-04-09

The antioxidant activity and phenolic composition of six in vitro cultured blueberry seedlings were determined. Extracts were prepared in 85% ethanol from 30 days old in vitro cultured plants and used to evaluate the antioxidant capacities that included Ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazin (DPPH•) scavenging ability, total polyphenols (TP) and the partial phenolic composition performed by high performance liquid chromatography with diode array detector (HPLC-DAD), liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS (ESI-QqQ)). All ethanolic extracts from in vitro blueberry cultivars displayed antioxidant activity, with Legacy, Elliott and Bluegold cultivars being the most active. In addition, we observed a positive correlation between phenolic content and antioxidant activity. Our results suggest that the antioxidant activity of the extracts is related to the content of chlorogenic acid myricetin, syringic acid and rutin, and tissue culture of blueberry seedlings is a good tool to obtain antioxidant extracts with reproducible profile of compounds.

In Vitro Cultivars of Vaccinium corymbosum L. (Ericaceae) are a Source of Antioxidant Phenolics

PubMed Central

Contreras, Rodrigo A.; Köhler, Hans; Pizarro, Marisol; Zúñiga, Gustavo E.

2015-01-01

The antioxidant activity and phenolic composition of six in vitro cultured blueberry seedlings were determined. Extracts were prepared in 85% ethanol from 30 days old in vitro cultured plants and used to evaluate the antioxidant capacities that included Ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazin (DPPH•) scavenging ability, total polyphenols (TP) and the partial phenolic composition performed by high performance liquid chromatography with diode array detector (HPLC-DAD), liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS (ESI-QqQ)). All ethanolic extracts from in vitro blueberry cultivars displayed antioxidant activity, with Legacy, Elliott and Bluegold cultivars being the most active. In addition, we observed a positive correlation between phenolic content and antioxidant activity. Our results suggest that the antioxidant activity of the extracts is related to the content of chlorogenic acid myricetin, syringic acid and rutin, and tissue culture of blueberry seedlings is a good tool to obtain antioxidant extracts with reproducible profile of compounds. PMID:26783705

Water Permeability Adjusts Resorption in Lung Epithelia to Increased Apical Surface Liquid Volumes.

PubMed

Schmidt, Hanna; Michel, Christiane; Braubach, Peter; Fauler, Michael; Neubauer, Daniel; Thompson, Kristin E; Frick, Manfred; Mizaikoff, Boris; Dietl, Paul; Wittekindt, Oliver H

2017-03-01

The apical surface liquid (ASL) layer covers the airways and forms a first line of defense against pathogens. Maintenance of ASL volume by airway epithelia is essential for maintaining lung function. The proteolytic activation of epithelial Na + channels is believed to be the dominating mechanism to cope with increases in ASL volumes. Alternative mechanisms, in particular increases in epithelial osmotic water permeability (P osm ), have so far been regarded as rather less important. However, most studies mainly addressed immediate effects upon apical volume expansion (AVE) and increases in ASL. This study addresses the response of lung epithelia to long-term AVE. NCI-H441 cells and primary human tracheal epithelial cells, both cultivated in air-liquid interface conditions, were used as models for the lung epithelium. AVE was established by adding isotonic solution to the apical surface of differentiated lung epithelia, and time course of ASL volume restoration was assessed by the deuterium oxide dilution method. Concomitant ion transport was investigated in Ussing chambers. We identified a low resorptive state immediately after AVE, which coincided with proteolytic ion transport activation within 10-15 minutes after AVE. The main clearance of excess ASL occurred during a delayed (hours after AVE) high resorptive state, which did not correlate with ion transport activation. Instead, high resorptive state onset coincided with an increase in P osm , which depended on aquaporin up-regulation. In summary, our data demonstrate that, aside from ion transport activation, modulation of P osm is a major mechanism to compensate for long-term AVE in lung epithelia.

Cellulase stability, adsorption/desorption profiles and recycling during successive cycles of hydrolysis and fermentation of wheat straw.

PubMed

Rodrigues, Ana Cristina; Felby, Claus; Gama, Miguel

2014-03-01

The potential of enzymes recycling after hydrolysis and fermentation of wheat straw under a variety of conditions was investigated, monitoring the activity of the enzymes in the solid and liquid fractions, using low molecular weight substrates. A significant amount of active enzymes could be recovered by recycling the liquid phase. In the early stage of the process, enzyme adsorb to the substrate, then gradually returning to the solution as the saccharification proceeds. At 50°C, normally regarded as an acceptable operational temperature for saccharification, the enzymes (Celluclast) significantly undergo thermal deactivation. The hydrolysis yield and enzyme recycling efficiency in consecutive recycling rounds can be increased by using high enzyme loadings and moderate temperatures. Indeed, the amount of enzymes in the liquid phase increased with its thermostability and hydrolytic efficiency. This study contributes towards developing effective enzymes recycling strategies and helping to reduce the enzyme costs on bioethanol production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Liquid-handling Lego robots and experiments for STEM education and research

PubMed Central

Gerber, Lukas C.; Calasanz-Kaiser, Agnes; Hyman, Luke; Voitiuk, Kateryna; Patil, Uday

2017-01-01

Liquid-handling robots have many applications for biotechnology and the life sciences, with increasing impact on everyday life. While playful robotics such as Lego Mindstorms significantly support education initiatives in mechatronics and programming, equivalent connections to the life sciences do not currently exist. To close this gap, we developed Lego-based pipetting robots that reliably handle liquid volumes from 1 ml down to the sub-μl range and that operate on standard laboratory plasticware, such as cuvettes and multiwell plates. These robots can support a range of science and chemistry experiments for education and even research. Using standard, low-cost household consumables, programming pipetting routines, and modifying robot designs, we enabled a rich activity space. We successfully tested these activities in afterschool settings with elementary, middle, and high school students. The simplest robot can be directly built from the widely used Lego Education EV3 core set alone, and this publication includes building and experiment instructions to set the stage for dissemination and further development in education and research. PMID:28323828

Vaporization of liquid Pb-Li eutectic alloy from 1000K to 1200K - A high temperature mass spectrometric study

NASA Astrophysics Data System (ADS)

Jain, U.; Mukherjee, A.; Dey, G. K.

2017-09-01

Liquid lead-lithium eutectic will be used as a coolant in fusion reactor blanket loop. Vapor pressure of the eutectic is an important parameter to accurately predict its in-loop behavior. Past measurements of vapor pressure of the eutectic relied on indirect methods. In this paper, we report for the first time the in-situ vaporization behavior of the liquid alloy between 1042 and 1176 K by Knudsen effusion mass spectrometry (KEMS). It was seen that the vaporization occurred by independent evaporation of lead and lithium. No complex intermetallic vapor was seen in the mass spectra. The partial pressures and enthalpy of vaporization of Pb and Li were evaluated directly from the measured ion intensities formed from the equilibrium vapor over the alloy. The activity of Li over a temperature range of 1042-1176 K was found to be 4.8 × 10-5 to that of pure Li, indicating its very low activity in the alloy.

Liquid-handling Lego robots and experiments for STEM education and research.

PubMed

Gerber, Lukas C; Calasanz-Kaiser, Agnes; Hyman, Luke; Voitiuk, Kateryna; Patil, Uday; Riedel-Kruse, Ingmar H

2017-03-01

Liquid-handling robots have many applications for biotechnology and the life sciences, with increasing impact on everyday life. While playful robotics such as Lego Mindstorms significantly support education initiatives in mechatronics and programming, equivalent connections to the life sciences do not currently exist. To close this gap, we developed Lego-based pipetting robots that reliably handle liquid volumes from 1 ml down to the sub-μl range and that operate on standard laboratory plasticware, such as cuvettes and multiwell plates. These robots can support a range of science and chemistry experiments for education and even research. Using standard, low-cost household consumables, programming pipetting routines, and modifying robot designs, we enabled a rich activity space. We successfully tested these activities in afterschool settings with elementary, middle, and high school students. The simplest robot can be directly built from the widely used Lego Education EV3 core set alone, and this publication includes building and experiment instructions to set the stage for dissemination and further development in education and research.

Self-Assembled Polymeric Ionic Liquid-Functionalized Cellulose Nano-crystals: Constructing 3D Ion-conducting Channels Within Ionic Liquid-based Composite Polymer Electrolytes.

PubMed

Shi, Qing Xuan; Xia, Qing; Xiang, Xiao; Ye, Yun Sheng; Peng, Hai Yan; Xue, Zhi Gang; Xie, Xiao Lin; Mai, Yiu-Wing

2017-09-04

Composite polymeric and ionic liquid (IL) electrolytes are some of the most promising electrolyte systems for safer battery technology. Although much effort has been directed towards enhancing the transport properties of polymer electrolytes (PEs) through nanoscopic modification by incorporating nano-fillers, it is still difficult to construct ideal ion conducting networks. Here, a novel class of three-dimensional self-assembled polymeric ionic liquid (PIL)-functionalized cellulose nano-crystals (CNC) confining ILs in surface-grafted PIL polymer chains, able to form colloidal crystal polymer electrolytes (CCPE), is reported. The high-strength CNC nano-fibers, decorated with PIL polymer chains, can spontaneously form three-dimensional interpenetrating nano-network scaffolds capable of supporting electrolytes with continuously connected ion conducting networks with IL being concentrated in conducting domains. These new CCPE have exceptional ionic conductivities, low activation energies (close to bulk IL electrolyte with dissolved Li salt), high Li + transport numbers, low interface resistances and improved interface compatibilities. Furthermore, the CCPE displays good electrochemical properties and a good battery performance. This approach offers a route to leak-free, non-flammable and high ionic conductivity solid-state PE in energy conversion devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural Effects of Gating Poly(3-hexylthiophene) through an Ionic Liquid

DOE PAGES

Guardado, Jesus O.; Salleo, Alberto

2017-07-17

Ionic liquids are increasingly employed as dielectrics to generate high charge densities and enable low-voltage operation with organic semiconductors. But, effects on structure and morphology of the active material are not fully known, particularly for permeable semiconductors such as conjugated polymers, in which ions from the ionic liquid can enter and electrochemically dope the semicrystalline film. In order to understand when ions enter, where they go, and how they affect the film, thin films of the archetypal semiconducting polymer, poly(3-hexylthiophene), are electrochemically doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, the archetypal ionic liquid. High-resolution, ex situ X-ray diffraction measurements and complete pole figuresmore » reveal changes with applied voltage, cycling, and frequency in lattice spacing, crystallite orientation, and crystallinity in the bulk and at the buried interface. Dopant ions penetrate the film and enter the crystallites at sufficiently high voltages and low frequencies. Upon infiltrating crystallites, ions permanently expand lamellar stacking and contract pi-stacking. Cycling amplifies these effects, but higher frequencies mitigate the expansion of bulk crystallites as ions are hindered from entering crystallites. Furthermore, this mechanistic understanding of the structural effects of ion penetration will help develop models of the frequency and voltage impedance response of electrochemically doped conjugated polymers and advance electronic applications.« less

Structural Effects of Gating Poly(3-hexylthiophene) through an Ionic Liquid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guardado, Jesus O.; Salleo, Alberto

Ionic liquids are increasingly employed as dielectrics to generate high charge densities and enable low-voltage operation with organic semiconductors. But, effects on structure and morphology of the active material are not fully known, particularly for permeable semiconductors such as conjugated polymers, in which ions from the ionic liquid can enter and electrochemically dope the semicrystalline film. In order to understand when ions enter, where they go, and how they affect the film, thin films of the archetypal semiconducting polymer, poly(3-hexylthiophene), are electrochemically doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, the archetypal ionic liquid. High-resolution, ex situ X-ray diffraction measurements and complete pole figuresmore » reveal changes with applied voltage, cycling, and frequency in lattice spacing, crystallite orientation, and crystallinity in the bulk and at the buried interface. Dopant ions penetrate the film and enter the crystallites at sufficiently high voltages and low frequencies. Upon infiltrating crystallites, ions permanently expand lamellar stacking and contract pi-stacking. Cycling amplifies these effects, but higher frequencies mitigate the expansion of bulk crystallites as ions are hindered from entering crystallites. Furthermore, this mechanistic understanding of the structural effects of ion penetration will help develop models of the frequency and voltage impedance response of electrochemically doped conjugated polymers and advance electronic applications.« less

Formative evaluation of a mobile liquid portion size estimation interface for people with varying literacy skills.

PubMed

Chaudry, Beenish Moalla; Connelly, Kay; Siek, Katie A; Welch, Janet L

2013-12-01

Chronically ill people, especially those with low literacy skills, often have difficulty estimating portion sizes of liquids to help them stay within their recommended fluid limits. There is a plethora of mobile applications that can help people monitor their nutritional intake but unfortunately these applications require the user to have high literacy and numeracy skills for portion size recording. In this paper, we present two studies in which the low- and the high-fidelity versions of a portion size estimation interface, designed using the cognitive strategies adults employ for portion size estimation during diet recall studies, was evaluated by a chronically ill population with varying literacy skills. The low fidelity interface was evaluated by ten patients who were all able to accurately estimate portion sizes of various liquids with the interface. Eighteen participants did an in situ evaluation of the high-fidelity version incorporated in a diet and fluid monitoring mobile application for 6 weeks. Although the accuracy of the estimation cannot be confirmed in the second study but the participants who actively interacted with the interface showed better health outcomes by the end of the study. Based on these findings, we provide recommendations for designing the next iteration of an accurate and low literacy-accessible liquid portion size estimation mobile interface.

High temperature ultrasonic transducers for imaging and measurements in a liquid Pb/Bi eutectic alloy.

PubMed

Kazys, Rymantas; Voleisis, Algirdas; Sliteris, Reimondas; Mazeika, Liudas; Van Nieuwenhove, Rudi; Kupschus, Peter; Abderrahim, Hamid Aït

2005-04-01

In some nuclear reactors or accelerator-driven systems (ADS) the core is intended to be cooled by means of a heavy liquid metal, for example, lead-bismuth (Pb/Bi) eutectic alloy. For safety and licensing reasons, an imaging method of the interior of ADS, based on application of ultrasonic waves, has thus to be developed. This paper is devoted to description of developed various ultrasonic transducers suitable for long term imaging and measurements in the liquid Pb/Bi alloy. The results of comparative experimental investigations of the developed transducers of different designs in a liquid Pb/Bi alloy up to 450 degrees C are presented. Prototypes with different high temperature piezoelectric materials were investigated: PZT, bismuth titanate (Bi4Ti3O12), lithium niobate (LiNbO3), gallium orthophosphate (GaPO4) and aluminum nitride (A1N). For acoustic coupling with the metal alloy, it was proposed to coat the active surface of the transducers by diamond like carbon (DLC). The radiation robustness was assessed by exposing the transducers to high gamma dose rates in one of the irradiation facilities at SCK x CEN. The experimental results proved that the developed transducers are suitable for long-term operation in harsh conditions.

A Simple System for Observing Dynamic Phase Equilibrium via an Inquiry-Based Laboratory or Demonstration

ERIC Educational Resources Information Center

Cloonan, Carrie A.; Andrew, Julie A.; Nichol, Carolyn A.; Hutchinson, John S.

2011-01-01

This article describes an activity that can be used as an inquiry-based laboratory or demonstration for either high school or undergraduate chemistry students to provide a basis for understanding both vapor pressure and the concept of dynamic phase equilibrium. The activity includes a simple setup to create a closed system of only water liquid and…

Active Uptake of Amino Acids by Leaves of an Epiphytic Vascular Plant, Tillandsia paucifolia (Bromeliaceae) 1

PubMed Central

Nyman, Leslie Paul; Davis, James P.; O'Dell, Stephen J.; Arditti, Joseph; Stephens, Grover C.; Benzing, David H.

1987-01-01

Specialized epidermal trichomes on the leaves of the epiphyte, Tillandsia paucifolia (Bromeliaceae) accumulate amino acids from solution. Simultaneous net uptake of 17 amino acids was determined using high performance liquid chromatography. Uptake occurs against concentration gradients at least as high as 104. Images Fig. 2 Fig. 3 PMID:16665307

Functional analysis of Pacific oyster (Crassostrea gigas) β-thymosin: Focus on antimicrobial activity.

PubMed

Nam, Bo-Hye; Seo, Jung-Kil; Lee, Min Jeong; Kim, Young-Ok; Kim, Dong-Gyun; An, Cheul Min; Park, Nam Gyu

2015-07-01

An antimicrobial peptide, ∼5 kDa in size, was isolated and purified in its active form from the mantle of the Pacific oyster Crassostrea gigas by C18 reversed-phase high-performance liquid chromatography. Matrix-assisted laser desorption ionisation time-of-flight analysis revealed 4656.4 Da of the purified and unreduced peptide. A comparison of the N-terminal amino acid sequence of oyster antimicrobial peptide with deduced amino acid sequences in our local expressed sequence tag (EST) database of C. gigas (unpublished data) revealed that the oyster antimicrobial peptide sequence entirely matched the deduced amino acid sequence of an EST clone (HM-8_A04), which was highly homologous with the β-thymosin of other species. The cDNA possessed a 126-bp open reading frame that encoded a protein of 41 amino acids. To confirm the antimicrobial activity of C. gigas β-thymosin, we overexpressed a recombinant β-thymosin (rcgTβ) using a pET22 expression plasmid in an Escherichia coli system. The antimicrobial activity of rcgTβ was evaluated and demonstrated using a bacterial growth inhibition test in both liquid and solid cultures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simultaneous determination of brazilin and protosappanin B in Caesalpinia sappan by ionic-liquid dispersive liquid-phase microextraction method combined with HPLC.

PubMed

Xia, Zhaoyang; Li, Dongdong; Li, Qing; Zhang, Yan; Kang, Wenyi

2017-11-13

The conditions of heating, ionic liquid-based ultrasonic-assisted extraction combined with reverse-phase high performance liquid chromatography were optimized to simultaneously isolate and determinate brazilin and protosappanin B in Caesalpinia sappan. Ionic liquids, including [BMIM]Br, [BMIM]BF 4 , [BMIM]PF 6 and [HMIM]PF 6 , were selected as extraction solvents while methanol, acetone, acetonitrile, ethanol and water were selected as dispersants. The chromatographic column was Purospher star RP-C 18 (250 mm × 4.6 mm, 5 μm), a mixture of methanol and 0.2% phosphoric acid-water was used as mobile phase at a flow rate 0.65 mL/min. The result displayed that the extraction yields of brazilin and protosappanin B were highest when the concentration of [BMIM]Br methanol solution as extraction solvent was 0.5 mol/L and the solid-liquid ratio was 1:50 (g/mL). Under the optimal extraction conditions, the contents of brazilin showed a good linearity (r = 1.0000) within the range of 1.25-7.50 μg with the average recovery of 99.33%, the contents of protosappanin B also showed a good linearity (r = 0.9999) within the range of 0.50-3.00 μg with the average recovery of 98.31%. This experiment, which adopted environmentally friendly reagent as extraction solvent, not only improved the extraction efficiency, but also avoided the environmental pollution caused by organic solvent. Moreover, it was simple and reliable, and can be of important significance in the study of Traditional Chinese Medicine active ingredient extraction methods. The antibacterial activities of the ionic liquids and methanol extracts were determined using the paper disc diffusion method. The ionic liquid extract was found to possess antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus (MIC value of 37.5 mg crude drug/mL), β-Lactamase producing S. aureus (MIC values of 18.8 mg crude drug/mL), but not against E. coli, Extended spectrum β-Lactamases E. coli and P. aeruginosa. Compared with the ionic liquid extract, the methanol extract was found to have antibacterial activity against S. aureus and methicillin-resistant S. aureus (MIC value of 75.0 mg crude drug/mL), β-Lactamase producing S. aureus (MIC values of 150.0 mg crude drug/mL). However, the same, the methanol extract did not have antibacterial activity against E. coli, Extended spectrum β-Lactamases E. coli and P. aeruginosa.

Hepatoprotective effect against CCl4-induced acute liver damage in mice and High-performance liquid chromatography mass spectrometric method for analysis of the constituents of extract of Rubus crataegifolius.

PubMed

Sun, Yongjiao; Jia, Lingyun; Huang, Zhanbo; Wang, Jing; Lu, Jincai; Li, Jing

2017-11-01

This study is an attempt to evaluate the hepatoprotective activity of Rubus Crataegifolius against carbon tetrachloride-induced liver injury in mice. 70% ethanolic, ethyl acetate and n-BuOH extract of R. crataegifolius were administered daily for 14 days in experimental animals before they were treated with CCl 4 . The hepatoprotective activity of the extracts in this study was compared with the reference drug silymarin. A high-performance liquid chromatography mass spectrometric (HPLC-EIS-MS/MS) method was developed for the determination of the constituents of the extracts. According to the data of HPLC-EIS-MS/MS, the chemical structures of the largely 14 constituents of R. crataegifolius were identified online without time-consuming isolation. Ethyl acetate extracts of R. crataegifolius showed strong antioxidant activities and significant protective effect against acute hepatotoxicity induced by CCl 4 . According to the data of HPLC-EIS-MS/MS, Oleanic acid, Phlorizin dehydrate and Quercetin-3-rhamnoside are considered as the main hepatoprotective factor in ethyl acetate extract.

An active coronagraph using a liquid crystal array for exoplanet imaging: principle and testing

NASA Astrophysics Data System (ADS)

Zhang, Xi; Ren, De-Qing; Zhu, Yong-Tian; Dou, Jiang-Pei

2012-05-01

High-contrast imaging coronagraphs, used for the detection of exoplanets, have always adopted passive coronagraph optical components. It is therefore impossible to actively optimize the coronagraphs to achieve their best performance. To solve this problem, we propose a novel high-contrast imaging coronagraph which combines a liquid crystal array (LCA) for active pupil apodization and a deformable mirror (DM) for phase correction. The LCA we use is an amplitude-only spatial light modulator. The LCA is well calibrated and compensates for its amplitude non-uniformity and nonlinear intensity responsivity. We measured the imaging contrasts of the coronagraph system with the LCA only and without the DM deployed. Imaging contrasts of 10-4 and 10-5 can be reached at an inner working angular distance of 2.5 and 5λ/D, respectively. A simulation shows that the phase errors on the coronagraph pupil limit the contrast performance. The contrast could be further improved if a DM is deployed to correct the phase errors induced by the LCA and coronagraph optics.

Antiproliferative activity of Curcuma phaeocaulis Valeton extract using ultrasonic assistance and response surface methodology.

PubMed

Wang, Xiaoqin; Jiang, Ying; Hu, Daode

2017-01-02

The objective of the study was to optimize the ultrasonic-assisted extraction of curdione, furanodienone, curcumol, and germacrone from Curcuma phaeocaulis Valeton (Val.) and investigate the antiproliferative activity of the extract. Under the suitable high-performance liquid chromatography condition, the calibration curves for these four tested compounds showed high levels of linearity and the recoveries of these four compounds were between 97.9 and 104.3%. Response surface methodology (RSM) combining central composite design and desirability function (DF) was used to define optimal extraction parameters. The results of RSM and DF revealed that the optimum conditions were obtained as 8 mL g -1 for liquid-solid ratio, 70% ethanol concentration, and 20 min of ultrasonic time. It was found that the surface structures of the sonicated herbal materials were fluffy and irregular. The C. phaeocaulis Val. extract significantly inhibited the proliferation of RKO and HT-29 cells in vitro. The results reveal that the RSM can be effectively used for optimizing the ultrasonic-assisted extraction of bioactive components from C. phaeocaulis Val. for antiproliferative activity.

Simultaneous determination of phenolic compounds in Equisetum palustre L. by ultra high performance liquid chromatography with tandem mass spectrometry combined with matrix solid-phase dispersion extraction.

PubMed

Wei, Zuofu; Pan, Youzhi; Li, Lu; Huang, Yuyang; Qi, Xiaolin; Luo, Meng; Zu, Yuangang; Fu, Yujie

2014-11-01

A method based on matrix solid-phase dispersion extraction followed by ultra high performance liquid chromatography with tandem mass spectrometry is presented for the extraction and determination of phenolic compounds in Equisetum palustre. This method combines the high efficiency of matrix solid-phase dispersion extraction and the rapidity, sensitivity, and accuracy of ultra high performance liquid chromatography with tandem mass spectrometry. The influential parameters of the matrix solid-phase dispersion extraction were investigated and optimized. The optimized conditions were as follows: silica gel was selected as dispersing sorbent, the ratio of silica gel to sample was selected to be 2:1 (400/200 mg), and 8 mL of 80% methanol was used as elution solvent. Furthermore, a fast and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the determination of nine phenolic compounds in E. palustre. This method was carried out within <6 min, and exhibited satisfactory linearity, precision, and recovery. Compared with ultrasound-assisted extraction, the proposed matrix solid-phase dispersion procedure possessed higher extraction efficiency, and was more convenient and time saving with reduced requirements on sample and solvent amounts. All these results suggest that the developed method represents an excellent alternative for the extraction and determination of active components in plant matrices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surface-active ionic liquids in micellar catalysis: impact of anion selection on reaction rates in nucleophilic substitutions† †Electronic supplementary information (ESI) available: Formulae for calculating aggregation parameters and fitting of kinetic constants and copies of NMR spectra. See DOI: 10.1039/c6cp00493h Click here for additional data file.

PubMed Central

Cognigni, Alice; Gaertner, Peter; Zirbs, Ronald; Peterlik, Herwig; Prochazka, Katharina; Schröder, Christian

2016-01-01

A series of surface-active ionic liquids based on the 1-dodecyl-3-methylimidazolium cation and different anions such as halides and alkylsulfates was synthesized. The aggregation behavior of these ionic liquids in water was characterized by surface tension, conductivity measurements and UV-Vis spectroscopy in order to determine the critical micelle concentration (CMC) and to provide aggregation parameters. The determination of surface activity and aggregation properties of amphiphilic ionic liquids was accompanied by SAXS studies on selected surface-active ionic liquids. The application of these surface-active ionic liquids with different anions was tested in nucleophilic substitution reactions for the degradation of organophosphorus compounds. Kinetic studies via UV-Vis spectrophotometry showed a strong acceleration of the reaction in the micellar system compared to pure water. In addition, an influence of the anion was observed, resulting in a correlation between the anion binding to the micelle and the reaction rate constants, indicating that the careful choice of the surface-active ionic liquid can considerably affect the outcome of reactions. PMID:27121134

In vitro activity of readily available household materials against HIV-1: is bleach enough?

PubMed

Flynn, N; Jain, S; Keddie, E M; Carlson, J R; Jennings, M B; Haverkos, H W; Nassar, N; Anderson, R; Cohen, S; Goldberg, D

1994-07-01

This report describes experiments assessing the effectiveness against HIV of potential disinfecting agents that are commonly available to IDU when they are sharing syringes. We exposed cell-free HIV, HIV-infected cells, and HIV-infected blood containing known quantities of HIV to household cleaning agents, alcohols, peroxide, and highly acidic materials for 1 min, in order to examine the effects of these materials on the infectivity of the HIV. Undiluted liquid laundry bleach and dilute liquid dish detergent reduced the number of culturable HIV to an undetectable level under the experimental conditions used. Diluted bleach was not completely effective. Other potential disinfecting agents, including ethanol, isopropyl alcohol, and hydrogen peroxide, were unable to disinfect high numbers of HIV-infected cells or infected blood. Liquid dish detergent warrants further study as a possible acceptable alternative to bleach. Our data provide support for recommendations to IDU that they disinfect shared syringes every time between users with full-strength liquid laundry bleach to reduce their risk of acquiring or transmitting HIV. When bleach is not available, liquid dish detergent or other available disinfecting agents such as rubbing alcohol, hydrogen peroxide, or high alcohol content beverages are more effective than water at disinfecting HIV, recognizing that these materials are less effective than bleach. Although these materials are effective, they should not be viewed as a substitute for decreased sharing of injection equipment by IDU, or increased availability of sterile needles and syringes.

Liquid-metal plasma-facing component research on the National Spherical Torus Experiment

NASA Astrophysics Data System (ADS)

Jaworski, M. A.; Khodak, A.; Kaita, R.

2013-12-01

Liquid metal plasma-facing components (PFCs) have been proposed as a means of solving several problems facing the creation of economically viable fusion power reactors. Liquid metals face critical issues in three key areas: free-surface stability, material migration and demonstration of integrated scenarios. To date, few demonstrations exist of this approach in a diverted tokamak and we here provide an overview of such work on the National Spherical Torus Experiment (NSTX). The liquid lithium divertor (LLD) was installed and operated for the 2010 run campaign using evaporated coatings as the filling method. Despite a nominal liquid level exceeding the capillary structure and peak current densities into the PFCs exceeding 100 kA m-2, no macroscopic ejection events were observed. The stability can be understood from a Rayleigh-Taylor instability analysis. Capillary restraint and thermal-hydraulic considerations lead to a proposed liquid-metal PFCs scheme of actively-supplied, capillary-restrained systems. Even with state-of-the-art cooling techniques, design studies indicate that the surface temperature with divertor-relevant heat fluxes will still reach temperatures above 700 °C. At this point, one would expect significant vapor production from a liquid leading to a continuously vapor-shielded regime. Such high-temperature liquid lithium PFCs may be possible on the basis of momentum-balance arguments.

A thermo-electric-driven flowing liquid lithium limiter/divertor for magnetic confined fusion

NASA Astrophysics Data System (ADS)

Ruzic, D. N.; Xu, Wenyu; Curreli, Davide; Andruczyk, Daniel; Mui, Travis

2012-10-01

The concept of using a liquid metal, especially liquid lithium, as the plasma facing surface may provide the best path forward toward reactor designs. A liquid PFC can effectively eliminate the erosion and thermal stress problems compared to the solid PFC while transferring heat and prolong the lifetime limit of the PFCs. A liquid lithium surface can also suppress the hydrogen isotopes recycling and getter the impurities in fusion reactor. The Lithium/metal infused trench (LiMIT) concept successfully proved that the thermoelectric effect can induce electric currents inside liquid lithium and an external magnetic field can drive liquid lithium to flow within metallic open trenches. IR camera and thermocouple measurements prove the strong heat transfer ability of this concept. A new flowing lithium system with active control of the temperature gradient inside the lithium trenches and back flow channels has been designed. TEMHD driven liquid lithium run steady state and pulsed for a few seconds of high heat flux (˜15MW/m^2) has been used to investigate the transient reaction of the flowing lithium. A similar tray is scheduled to be tested in HT-7, Hefei, China as a limiter in Sept. 2012. Related movies and analysis will be shown.

Dynamic and spectroscopic characteristics of atmospheric gliding arc in gas-liquid two-phase flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tu, X.; Yu, L.; Yan, J. H.

In this study, an atmospheric alternating-current gliding arc device in gas-liquid two-phase flow has been developed for the purpose of waste water degradation. The dynamic behavior of the gas-liquid gliding arc is investigated through the oscillations of electrical signals, while the spatial evolution of the arc column is analyzed by high speed photography. Different arc breakdown regimes are reported, and the restrike mode is identified as the typical fluctuation characteristic of the hybrid gliding arc in air-water mixture. Optical emission spectroscopy is employed to investigate the active species generated in the gas-liquid plasma. The axial evolution of the OH (309more » nm) intensity is determined, while the rotational and vibrational temperatures of the OH are obtained by a comparison between the experimental and simulated spectra. The significant discrepancy between the rotational and translational temperatures has also been discussed.« less

Polymerized Paired Ions as Polymeric Ionic Liquid-Proton Conductivity.

PubMed

Gu, Hong; Yan, Feng; Texter, John

2016-07-01

A new polymerized ionic liquid has been derived by photopolymerization of a stimuli-responsive ionic liquid surfactant, ILAMPS, which is composed of polymerizable, paired ions. The cation is 1-methyl-3-[11-(acryloyloxy)undecyl] imidazolium (IL), and the anion is 2-acrylamido-2-methyl-1-propanesulfonate (AMPS). This ion combination is a new ionic liquid. The resulting hygroscopic resins are highly polarizable, suitable for sensor design and for ultracapacitor fabrication and proton conducting. Interactions of imidazolium with anions provide basis for stimuli-responsiveness, and are used to promote proton transport. Doping with one equivalent of HPF6 at 0% relative humidity produces a 100-fold increase in proton conductivity at 100-125 °C and activation energies for proton transport lower than those of Nafion at water loadings less than 5 per sulfonate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoelectron spectrometer for attosecond spectroscopy of liquids and gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, I.; Huppert, M.; Wörner, H. J., E-mail: hwoerner@ethz.ch

2015-12-15

A new apparatus for attosecond time-resolved photoelectron spectroscopy of liquids and gases is described. It combines a liquid microjet source with a magnetic-bottle photoelectron spectrometer and an actively stabilized attosecond beamline. The photoelectron spectrometer permits venting and pumping of the interaction chamber without affecting the low pressure in the flight tube. This pressure separation has been realized through a sliding skimmer plate, which effectively seals the flight tube in its closed position and functions as a differential pumping stage in its open position. A high-harmonic photon spectrometer, attached to the photoelectron spectrometer, exit port is used to acquire photon spectramore » for calibration purposes. Attosecond pulse trains have been used to record photoelectron spectra of noble gases, water in the gas and liquid states as well as solvated species. RABBIT scans demonstrate the attosecond resolution of this setup.« less

Alcohol Oxidation at Platinum–Gas and Platinum–Liquid Interfaces: The Effect of Platinum Nanoparticle Size, Water Coadsorption, and Alcohol Concentration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tatsumi, Hironori; Liu, Fudong; Han, Hui-Ling

Platinum nanoparticles size range from 1 to 8 nm deposited on mesoporous silica MCF-17 catalyzed alcohol oxidations were studied in the gas and liquid phases. Among methanol, ethanol, 2- propanol and 2-butanol reactions, the turnover frequency increased with Pt nanoparticle size for all the alcohols utilized. The activation energies for the oxidations were almost same among all alcohol species, but higher in the gas phase than those in the liquid phase. Water coadsorption poisoned the reaction in the gas phase, while it increased the reaction turnover rates in the liquid phase. Sum frequency generation (SFG) vibrational spectroscopy studies and DFTmore » calculations revealed that the alcohol molecules pack horizontally on the metal surface in low concentrations and stand up in high concentrations, which affect the dissociation of β-hydrogen of the alcohols as the critical step in alcohol oxidations.« less

Alcohol Oxidation at Platinum–Gas and Platinum–Liquid Interfaces: The Effect of Platinum Nanoparticle Size, Water Coadsorption, and Alcohol Concentration

DOE PAGES

Tatsumi, Hironori; Liu, Fudong; Han, Hui-Ling; ...

2017-03-21

Platinum nanoparticles size range from 1 to 8 nm deposited on mesoporous silica MCF-17 catalyzed alcohol oxidations were studied in the gas and liquid phases. Among methanol, ethanol, 2- propanol and 2-butanol reactions, the turnover frequency increased with Pt nanoparticle size for all the alcohols utilized. The activation energies for the oxidations were almost same among all alcohol species, but higher in the gas phase than those in the liquid phase. Water coadsorption poisoned the reaction in the gas phase, while it increased the reaction turnover rates in the liquid phase. Sum frequency generation (SFG) vibrational spectroscopy studies and DFTmore » calculations revealed that the alcohol molecules pack horizontally on the metal surface in low concentrations and stand up in high concentrations, which affect the dissociation of β-hydrogen of the alcohols as the critical step in alcohol oxidations.« less

Preparation of Fiber Based Binder Materials to Enhance the Gas Adsorption Efficiency of Carbon Air Filter.

PubMed

Lim, Tae Hwan; Choi, Jeong Rak; Lim, Dae Young; Lee, So Hee; Yeo, Sang Young

2015-10-01

Fiber binder adapted carbon air filter is prepared to increase gas adsorption efficiency and environmental stability. The filter prevents harmful gases, as well as particle dusts in the air from entering the body when a human inhales. The basic structure of carbon air filter is composed of spunbond/meltblown/activated carbon/bottom substrate. Activated carbons and meltblown layer are adapted to increase gas adsorption and dust filtration efficiency, respectively. Liquid type adhesive is used in the conventional carbon air filter as a binder material between activated carbons and other layers. However, it is thought that the liquid binder is not an ideal material with respect to its bonding strength and liquid flow behavior that reduce gas adsorption efficiency. To overcome these disadvantages, fiber type binder is introduced in our study. It is confirmed that fiber type binder adapted air filter media show higher strip strength, and their gas adsorption efficiencies are measured over 42% during 60 sec. These values are higher than those of conventional filter. Although the differential pressure of fiber binder adapted air filter is relatively high compared to the conventional one, short fibers have a good potential as a binder materials of activated carbon based air filter.

Hydrocarbon liquid production via the bioCRACK process and catalytic hydroprocessing of the product oil

DOE PAGES

Schwaiger, Nickolaus; Elliott, Douglas C.; Ritzberger, Jurgen; ...

2015-01-01

Continuous hydroprocessing of liquid phase pyrolysis bio-oil, provided by BDI-BioEnergy International bioCRACK pilot plant at OMV Refinery in Schwechat/Vienna Austria was investigated. These hydroprocessing tests showed promising results using catalytic hydroprocessing strategies developed for unfractionated bio-oil. A sulfided base metal catalyst (CoMo on Al2O3) was evaluated. The bed of catalyst was operated at 400 °C in a continuous-flow reactor at a pressure of 12.1 MPa with flowing hydrogen. The condensed liquid products were analyzed and found that the hydrocarbon liquid was significantly hydrotreated so that nitrogen and sulfur were below the level of detection (<0.05), while the residual oxygen rangedmore » from 0.7 to 1.2%. The density of the products varied from 0.71 g/mL up to 0.79 g/mL with a correlated change of the hydrogen to carbon atomic ratio from 2.1 down to 1.9. The product quality remained high throughout the extended tests suggesting minimal loss of catalyst activity through the test. These tests provided the data needed to assess the quality of liquid fuel products obtained from the bioCRACK process as well as the activity of the catalyst for comparison with products obtained from hydrotreated fast pyrolysis bio-oils from fluidized-bed operation.« less

Liquid chromatography-tandem mass spectrometry detection of the quaternary ammonium compound mebezonium as an active ingredient in t61.

PubMed

Kirschbaum, Katrin M; Grellner, Wolfgang; Rochholz, Gertrud; Musshoff, Frank; Madea, Burkhard

2011-03-01

Quaternary ammonium compounds pose an analytical challenge. Mebezonium, a muscle-relaxing agent contained in veterinary euthanasia solution T61, was analyzed in body fluids, organs, and injection sites of a veterinarian by liquid chromatography-tandem mass spectrometry (LC-MS-MS) method. Additionally, embutramide and tetracaine, which are two other active ingredients contained in T61, methadone, xylazine, and analgesics were detected by LC-MS-MS and high-performance liquid chromatography-ultraviolet detection methods. For detection of mebezonium a solid-phase extraction (SPE) combined with ionpairing reagent heptafluorobutyric acid was developed. Separation was achieved on Phenomenex Synergi Hydro RP C(18) column combined with ammonium formate buffer and acetonitrile (pH 3.5). To enrich other drugs, liquid-liquid extraction procedures were used. Most of these drugs were separated on a Restek Allure PFP Propyl column using the mentioned mobile phase. Mebezonium and embutramide were detected in femoral vein serum in concentrations of 10.9 and 2.0 mg/L, respectively. The concentration of xylazine and methadone in serum was 2.0 and 0.4 mg/L, respectively. The LC-MS-MS method with SPE combined with an ion-pairing reagent allowed the quantitation of mebezonium. Methadone was detected in toxic concentrations and was, in combination with xylazine and T61, considered to be the cause of death.

Reduction of 68Ge activity containing liquid waste from 68Ga PET chemistry in nuclear medicine and radiopharmacy by solidification.

PubMed

de Blois, Erik; Chan, Ho Sze; Roy, Kamalika; Krenning, Eric P; Breeman, Wouter A P

PET with 68 Ga from the TiO 2 - or SnO 2 - based 68 Ge/ 68 Ga generators is of increasing interest for PET imaging in nuclear medicine. In general, radionuclidic purity ( 68 Ge vs. 68 Ga activity) of the eluate of these generators varies between 0.01 and 0.001%. Liquid waste containing low amounts of 68 Ge activity is produced by eluting the 68 Ge/ 68 Ga generators and residues from PET chemistry. Since clearance level of 68 Ge activity in waste may not exceed 10 Bq/g, as stated by European Directive 96/29/EURATOM, our purpose was to reduce 68 Ge activity in solution from >10 kBq/g to <10 Bq/g; which implies the solution can be discarded as regular waste. Most efficient method to reduce the 68 Ge activity is by sorption of TiO 2 or Fe 2 O 3 and subsequent centrifugation. The required 10 Bq per mL level of 68 Ge activity in waste was reached by Fe 2 O 3 logarithmically, whereas with TiO 2 asymptotically. The procedure with Fe 2 O 3 eliminates ≥90% of the 68 Ge activity per treatment. Eventually, to simplify the processing a recirculation system was used to investigate 68 Ge activity sorption on TiO 2 , Fe 2 O 3 or Zeolite. Zeolite was introduced for its high sorption at low pH, therefore 68 Ge activity containing waste could directly be used without further interventions. 68 Ge activity containing liquid waste at different HCl concentrations (0.05-1.0 M HCl), was recirculated at 1 mL/min. With Zeolite in the recirculation system, 68 Ge activity showed highest sorption.

Study on the Equilibrium Between Liquid Iron and Calcium Vapor

NASA Astrophysics Data System (ADS)

Berg, Martin; Lee, Jaewoo; Sichen, Du

2017-06-01

The solubility of calcium in liquid iron at 1823 K and 1873 K (1550 °C and 1600 °C) as a function of calcium potential was studied experimentally. The measurements were performed using a closed molybdenum holder in which liquid calcium and liquid iron were held at different temperatures. The results indicate a linear relationship between the activity of calcium, relative to pure liquid calcium, and the mole fraction of dissolved calcium in liquid iron, with a negligible temperature dependency in the ranges studied. The activity coefficient of calcium in liquid iron at infinite dilution, γ_{Ca(l0°, was calculated as 1551.

An Efficient Strategy Based on Liquid-Liquid Extraction with Three-Phase Solvent System and High Speed Counter-Current Chromatography for Rapid Enrichment and Separation of Epimers of Minor Bufadienolide from Toad Meat.

PubMed

Zou, Denglang; Zhu, Xuelin; Zhang, Fan; Du, Yurong; Ma, Jianbin; Jiang, Renwang

2018-01-31

This study presents an efficient strategy based on liquid-liquid extraction with three-phase solvent system and high speed counter-current chromatography for rapid enrichment and separation of epimers of minor bufadienolide from toad meat. The reflux extraction conditions were optimized by response surface methodology first, and a novel three-phase solvent system composed of n-hexane/methyl acetate/acetonitrile/water (3:6:5:5, v/v) was developed for liquid-liquid extraction of the crude extract. This integrative extraction process could enrich minor bufadienolide from complex matrix efficiently and minimize the loss of minor targets induced by repeated extraction with different kinds of organic solvents occurring in the classical liquid two-phase extraction. As a result, four epimers of minor bufadienolide were greatly enriched in the middle phase and total content of these epimers of minor bufadienolide was increased from 3.25% to 46.23%. Then, the enriched four epimers were separated by HSCCC with a two-phase solvent system composed of chloroform/methanol/water (4:2:2, v/v) successfully. Furthermore, we tested Na + ,K + -ATPase (NKA) inhibitory effect of the four epimers. 3β-Isomers of bufadienolide showed stronger (>8-fold) inhibitory activity than 3α-isomers. The characterization of minor bufadienolide in toad meat and their significant difference of inhibitory effect on NKA would promote the further quantitative analysis and safety evaluation of toad meat as a food source.

Facile synthesis of pristine graphene-palladium nanocomposites with extraordinary catalytic activities using swollen liquid crystals

NASA Astrophysics Data System (ADS)

Vats, T.; Dutt, S.; Kumar, R.; Siril, P. F.

2016-09-01

Amazing conductivity, perfect honeycomb sp2 arrangement and the high theoretical surface area make pristine graphene as one of the best materials suited for application as catalyst supports. Unfortunately, the low reactivity of the material makes the formation of nanocomposite with inorganic materials difficult. Here we report an easy approach to synthesize nanocomposites of pristine graphene with palladium (Pd-G) using swollen liquid crystals (SLCs) as a soft template. The SLC template gives the control to deposit very small Pd particles of uniform size on G as well as RGO. The synthesized nanocomposite (Pd-G) exhibited exceptionally better catalytic activity compared with Pd-RGO nanocomposite in the hydrogenation of nitrophenols and microwave assisted C-C coupling reactions. The catalytic activity of Pd-G nanocomposite during nitrophenol reduction reaction was sixteen times higher than Pd nanoparticles and more than double than Pd-RGO nanocomposite. The exceptionally high activity of pristine graphene supported catalysts in the organic reactions is explained on the basis of its better pi interacting property compared to partially reduced RGO. The Pd-G nanocomposite showed exceptional stability under the reaction conditions as it could be recycled upto a minimum of 15 cycles for the C-C coupling reactions without any loss in activity.

Catalytic Conversion of Carbohydrates to Levulinate Ester over Heteropolyanion-Based Ionic Liquids.

PubMed

Song, Changhua; Liu, Sijie; Peng, Xinwen; Long, Jinxing; Lou, Wenyong; Li, Xuehui

2016-12-08

An efficient one-pot approach for the production of levulinate ester from renewable carbohydrates is demonstrated over heteropolyanion-based ionic liquid (IL-POM) catalysts with alcohols as the promoters and solvents. The relationships between the structure, acidic strength, and solubility of the IL-POM in methanol and the catalytic performance were studied intensively. A cellulose conversion of 100 % could be achieved with a 71.4 % yield of methyl levulinate over the catalyst [PyPS] 3 PW 12 O 40 [PyPS=1-(3-sulfopropyl)pyridinium] at 150 °C for 5 h. This high efficiency is ascribed to the reasonably high activity of the ionic liquid (IL) catalyst and reaction coupling with rapid in situ esterification of the generated levulinic acid with the alcohol promoter, which allows the insolubility of cellulose encountered in biomass conversion to be overcome. Furthermore, the present process exhibits high feedstock adaptability for typical carbohydrates and handy catalyst recovery by a simple self-separation procedure through temperature control. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phytochemical composition of fractions isolated from ten Salvia species by supercritical carbon dioxide and pressurized liquid extraction methods.

PubMed

Šulniūtė, Vaida; Pukalskas, Audrius; Venskutonis, Petras Rimantas

2017-06-01

Ten Salvia species, S. amplexicaulis, S. austriaca, S. forsskaolii S. glutinosa, S. nemorosa, S. officinalis, S. pratensis, S. sclarea, S. stepposa and S. verticillata were fractionated using supercritical carbon dioxide and pressurized liquid (ethanol and water) extractions. Fifteen phytochemicals were identified using commercial standards (some other compounds were identified tentatively), 11 of them were quantified by ultra high pressure chromatography (UPLC) with quadruple and time-of-flight mass spectrometry (Q/TOF, TQ-S). Lipophilic CO 2 extracts were rich in tocopherols (2.36-10.07mg/g), while rosmarinic acid was dominating compound (up to 30mg/g) in ethanolic extracts. Apigenin-7-O-β-d-glucuronide, caffeic and carnosic acids were quantitatively important phytochemicals in the majority other Salvia spp. Antioxidatively active constituents were determined by using on-line high-performance liquid chromatography (HPLC) analysis combined with 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay (HPLC-DPPH). Development of high pressure isolation process and comprehensive characterisation of phytochemicals in Salvia spp. may serve for their wider applications in functional foods and nutraceuticals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation and stability evaluation of extemporaneous oral suspension of valsartan using commercially available tablets.

PubMed

Zaid, Abdel Naser; Assali, Mohyeddin; Qaddomi, Aiman; Ghanem, Mashhour; Zaaror, Yara Abu

2014-01-01

The aim of this study was to develop an extemporaneous valsartan suspension (80 mg valsartan/5 mL) starting from commercial tablets (80-mg/ tablet). A high-performance liquid chromatographic system was used for the analysis and quantification of valsartan in the samples studied. Samples of valsartan suspension for analysis were prepared as reported by the validated high-performance liquid chromatographic method and the dissolution tests were performed according to the U.S. Food and Drug Administration's method. The high-performance liquid chromatographic assay indicated that the 80-mg/5-mL valsartan suspension was stable for 30 days when stored at long-term and accelerated storage conditions. Valsartan release profile showed that approximately 85% of valsartan dissolved after 10 minutes and, accordingly, the calculation of similarity factor was not necessary. It is possible for the pharmacist to crush valsartan 80-mg tablets and prepare a suspension which has dosage flexibility that can be calculated according to body-surface area, kidney, and liver functions, without affecting the chemical stability of the active ingredient nor its dissolution profile and also have a cost-effective dosage form.

Separation and identification of corticosterone metabolites by liquid chromatography--electrospray ionization mass spectrometry.

PubMed

Miksík, I; Vylitová, M; Pácha, J; Deyl, Z

1999-04-16

High-performance liquid chromatography coupled to atmospheric pressure ionization-electrospray ionization mass spectrometry (API-ESI-MS) was investigated for the analysis of corticosterone metabolites; their characterization was obtained by combining the separation on Zorbax Eclipse XDB C18 column (eluted with a methanol-water-acetic acid gradient) with identification using positive ion mode API-ESI-MS and selected ion analysis. The applicability of this method was verified by monitoring the activity of steroid converting enzymes (20beta-hydroxysteroid dehydrogenase and 11beta-hydroxysteroid dehydrogenase) in avian intestines.

In vitro vasorelaxation mechanisms of bioactive compounds extracted from Hibiscus sabdariffa on rat thoracic aorta

PubMed Central

Sarr, Mamadou; Ngom, Saliou; Kane, Modou O; Wele, Alassane; Diop, Doudou; Sarr, Bocar; Gueye, Lamine; Andriantsitohaina, Ramaroson; Diallo, Aminata S

2009-01-01

Background In this study, we suggested characterizing the vasodilator effects and the phytochemical characteristics of a plant with food usage also used in traditional treatment of arterial high blood pressure in Senegal. Methods Vascular effects of crude extract of dried and powdered calyces of Hibiscus sabdariffa were evaluated on isolated thoracic aorta of male Wistar rats on organ chambers. The crude extract was also enriched by liquid-liquid extraction. The various cyclohexane, dichloromethane, ethyl acetate, butanol extracts obtained as well as the residual marc were subjected to Sephadex LH-20 column chromatography. The different methanolic eluate fractions were then analyzed by Thin Layer (TLC) and High Performance Liquid Chromatography (HPLC) and their vascular effects also evaluated. Results The H. Sabdariffa crude extract induced mainly endothelium-dependent relaxant effects. The endothelium-dependent relaxations result from NOS activation and those who not dependent to endothelium from activation of smooth muscle potassium channels. The phytochemical analysis revealed the presence of phenolic acids in the ethyl acetate extract and anthocyans in the butanolic extract. The biological efficiency of the various studied extracts, in term of vasorelaxant capacity, showed that: Butanol extract > Crude extract > Residual marc > Ethyl acetate extract. These results suggest that the strong activity of the butanolic extract is essentially due to the presence of anthocyans found in its fractions 43-67. Conclusion These results demonstrate the vasodilator potential of hibiscus sabdariffa and contribute to his valuation as therapeutic alternative. PMID:19883513

Screening and analysis of potential anti-tumor components from the stipe of Ganoderma sinense using high-performance liquid chromatography/time-of-flight mass spectrometry with multivariate statistical tool.

PubMed

Chan, Kar-Man; Yue, Grace Gar-Lee; Li, Ping; Wong, Eric Chun-Wai; Lee, Julia Kin-Ming; Kennelly, Edward J; Lau, Clara Bik-San

2017-03-03

According to Chinese Pharmacopoeia 2015 edition, Ganoderma (Lingzhi) is a species complex that comprise of Ganoderma lucidum and Ganoderma sinense. The bioactivity and chemical composition of G. lucidium had been studied extensively, and it was shown to possess antitumor activities in pharmacological studies. In contrast, G. sinense has not been studied in great detail. Our previous studies found that the stipe of G. sinense exhibited more potent antitumor activity than the pileus. To identify the antitumor compounds in the stipe of G. sinense, we studied its chemical components by merging the bioactivity results with liquid chromatography-mass spectrometry-based chemometrics. The stipe of G. sinense was extracted with water, followed by ethanol precipitation and liquid-liquid partition. The resulting residue was fractionated using column chromatography. The antitumor activity of these fractions were analysed using MTT assay in murine breast tumor 4T1 cells, and their chemical components were studied using the LC-QTOF-MS with multivariate statistical tools. The chemometric and MS/MS analysis correlated bioactivity with five known cytotoxic compounds, 4-hyroxyphenylacetate, 9-oxo-(10E,12E)-octadecadienoic acid, 3-phenyl-2-propenoic acid, 13-oxo-(9E,11E)-octadecadienoic acid and lingzhine C, from the stipe of G. sinense. To the best of our knowledge, 4-hyroxyphenylacetate, 3-phenyl-2-propenoic acid and lingzhine C are firstly reported to be found in G. sinense. These five compounds will be investigated for their antitumor activities in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of advanced techniques for the extraction of phenolic compounds from Tunisian olive leaves: phenolic composition and cytotoxicity against human breast cancer cells.

PubMed

Taamalli, Amani; Arráez-Román, David; Barrajón-Catalán, Enrique; Ruiz-Torres, Verónica; Pérez-Sánchez, Almudena; Herrero, Miguel; Ibañez, Elena; Micol, Vicente; Zarrouk, Mokhtar; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

2012-06-01

A comparison among different advanced extraction techniques such as microwave-assisted extraction (MAE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), together with traditional solid-liquid extraction, was performed to test their efficiency towards the extraction of phenolic compounds from leaves of six Tunisian olive varieties. Extractions were carried out at the best selected conditions for each technique; the obtained extracts were chemically characterized using high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap tandem mass spectrometry (ESI-IT-MS(2)). As expected, higher extraction yields were obtained for PLE while phenolic profiles were mainly influenced by the solvent used as optimum in the different extraction methods. A larger number of phenolic compounds, mostly of a polar character, were found in the extracts obtained by using MAE. Best extraction yields do not correlate with highest cytotoxic activity against breast cancer cells, indicating that cytotoxicity is highly dependent on the presence of certain compounds in the extracts, although not exclusively on a single compound. Therefore, a multifactorial behavior is proposed for the anticancer activity of olive leaf compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

Single-exponential activation behavior behind the super-Arrhenius relaxations in glass-forming liquids.

PubMed

Wang, Lianwen; Li, Jiangong; Fecht, Hans-Jörg

2010-11-17

The reported relaxation time for several typical glass-forming liquids was analyzed by using a kinetic model for liquids which invoked a new kind of atomic cooperativity--thermodynamic cooperativity. The broadly studied 'cooperative length' was recognized as the kinetic cooperativity. Both cooperativities were conveniently quantified from the measured relaxation data. A single-exponential activation behavior was uncovered behind the super-Arrhenius relaxations for the liquids investigated. Hence the mesostructure of these liquids and the atomic mechanism of the glass transition became clearer.

Abuse liability assessment of an e-cigarette refill liquid using intracranial self-stimulation and self-administration models in rats

PubMed Central

LeSage, MG; Staley, M; Muelken, P; Smethells, JR; Stepanov, I; Vogel, RI; Pentel, PR; Harris, AC

2016-01-01

Background The popularity of electronic cigarettes (ECs) has increased dramatically despite their unknown health consequences. Because the abuse liability of ECs is one of the leading concerns of the Food and Drug Administration (FDA), models to assess it are urgently needed to inform FDA regulatory decisions regarding these products. The purpose of this study was to assess the relative abuse liability of an EC liquid compared to nicotine alone in rats. Because this EC liquid contains non-nicotine constituents that may enhance its abuse liability, we hypothesized that it would have greater abuse liability than nicotine alone. Methods Nicotine alone and nicotine dose-equivalent concentrations of EC liquid were compared in terms of their acute effects on intracranial self-stimulation (ICSS) thresholds, acquisition of self-administration, reinforcing efficacy (i.e., elasticity of demand), blockade of these behavioral effects by mecamylamine, nicotine pharmacokinetics and nicotinic acetylcholine receptor binding and activation. Results There were no significant differences between formulations on any measure, except that EC liquid produced less of an elevation in ICSS thresholds at high nicotine doses. Conclusions Collectively, these findings suggest that the relative abuse liability of this EC liquid is similar to that of nicotine alone in terms of its reinforcing and reinforcement-enhancing effects, but that it may have less aversive/anhedonic effects at high doses. The present methods may be useful for assessing the abuse liability of other ECs to inform potential FDA regulation of those products. PMID:27627814

High-Performance Computing Data Center Warm-Water Liquid Cooling |

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Active damping of capillary oscillations on liquid columns

NASA Astrophysics Data System (ADS)

Thiessen, David B.; Wei, Wei; Marston, Philip L.

2002-05-01

Active control of acoustic radiation pressure and of electrostatic stresses on liquid columns has been demonstrated to overcome the Rayleigh-Plateau instability that normally causes long liquid columns to break [M. J. Marr-Lyon et al., J. Fluid Mech. 351, 345 (1997); Phys. Fluids 12, 986-995 (2000)]. Though originally demonstrated for liquid-liquid systems in plateau tanks, the electrostatic method also works on columns in air in reduced gravity [D. B. Thiessen, M. J. Marr-Lyon, and P. L. Marston, ``Active electrostatic stabilization of liquid bridges in low gravity,'' J. Fluid Mech. (in press)]. In new research, the electrostatic stresses are applied in proportion to the velocity of the surface of the column so as to actively dampen capillary oscillations of the surface. The mode amplitude is optically sensed and the rate-of-change is electronically determined. Plateau tank measurements and theory both show that the change in damping rate is proportional to the feedback gain. The results suggest that either active control of electrostatic stresses or of acoustic radiation stresses can be used to suppress the response of interfaces to vibration. [Work supported by NASA.

A marine algicidal Thalassospira and its active substance against the harmful algal bloom species Karenia mikimotoi.

PubMed

Lu, Xiuhua; Zhou, Bin; Xu, Lili; Liu, Lin; Wang, Gangyuan; Liu, Xiaodong; Tang, Xuexi

2016-06-01

The aim of the present study was to obtain a marine bacterium active against Karenia mikimotoi from the East China Sea and to characterize its extracellular algicidal substances. Using preparative high-performance liquid chromatography (prep-HPLC) and electrospray ionization/quadrupole-time of flight mass spectrometer coupled with a high-performance liquid chromatography (LC/MS-Q-TOF) system, we purified the alga-lysing substance produced by strain ZR-2 and determined its molecular structure. Based on morphology and l6S ribosomal DNA (rDNA) sequence analysis, the ZR-2 strain was highly homologous to Thalassospira species. Algicidal activity against K. mikimotoi was detected in the cell-free filtrate but not in bacterial cells. The alga-lysing substance produced by ZR-2 was ethanol-soluble and thermostable, with a retention time of 6.3 min and a measured elemental composition of C7H5O2 ([M-H](-) ion at m/z 121.0295). The alga-lysing substance produced by ZR-2 was determined to be benzoic acid. Compared with the negative control, both purified ZR-2 bacteria-free filtrate and standard benzoic acid promoted K. mikimotoi cell disruption and induced K. mikimotoi cell content leakage. Our study is the first to report benzoic acid activity against K. mikimotoi as well as production of benzoic acid by a Thalassospira species.

Entropy-scaling laws for diffusion coefficients in liquid metals under high pressures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Qi-Long, E-mail: qlcao@mail.ustc.edu.cn; Shao, Ju-Xiang; Wang, Fan-Hou, E-mail: eatonch@gmail.com

2015-04-07

Molecular dynamic simulations on the liquid copper and tungsten are used to investigate the empirical entropy-scaling laws D{sup *}=A exp(BS{sub ex}), proposed independently by Rosenfeld and Dzugutov for diffusion coefficient, under high pressure conditions. We show that the scaling laws hold rather well for them under high pressure conditions. Furthermore, both the original diffusion coefficients and the reduced diffusion coefficients exhibit an Arrhenius relationship D{sub M}=D{sub M}{sup 0} exp(−E{sub M}/K{sub B}T), (M=un,R,D) and the activation energy E{sub M} increases with increasing pressure, the diffusion pre-exponential factors (D{sub R}{sup 0} and D{sub D}{sup 0}) are nearly independent of the pressure and element. Themore » pair correlation entropy, S{sub 2}, depends linearly on the reciprocal temperature S{sub 2}=−E{sub S}/T, and the activation energy, E{sub S}, increases with increasing pressure. In particular, the ratios of the activation energies (E{sub un}, E{sub R}, and E{sub D}) obtained from diffusion coefficients to the activation energy, E{sub S}, obtained from the entropy keep constants in the whole pressure range. Therefore, the entropy-scaling laws for the diffusion coefficients and the Arrhenius law are linked via the temperature dependence of entropy.« less

Antioxidant activity, phenolic-flavonoid content and high-performance liquid chromatography profiling of three different variants of Syzygium cumini seeds: A comparative study.

PubMed

Priya, Syama Hari; Prakasan, Nisha; Purushothaman, Jayamurthy

2017-01-01

The medicinally important phytochemicals present in Syzygium cumini seeds probably accounts for its wide use in traditional systems of medicines in India, like Ayurveda, Unani, and Siddha. The aim of the study was to determine the antioxidant potential of three different geographical variants of S. cumini seeds and to compare the phenolic profiling to know the effect of geographical variation in phenolic composition. Total phenolic and flavonoid content of S. cumini seeds were analyzed. Antioxidant activities in terms of 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), nitric oxide and superoxide radical scavenging assays were performed. The most active fractions were subjected to high-performance liquid chromatography (HPLC) profiling to identify the phenolic composition. Among all the fractions, 70% methanol fraction of S. cumini seed showed significant antioxidant potential. There existed a linear correlation between phenolic content and antioxidant activity. HPLC profiling of 70% methanol (ME) fractions of all the variants revealed the presence of phenolic compounds with high concentrations of ellagic acid and gallic acid. The differences in phenolic concentration due to geographical changes might be the reason for higher antioxidant potential showed by 70% ME of Trivandrum variant. 70% methanolic fraction of S. cumini can act as a novel source of natural antioxidant.

Decontamination formulation with sorbent additive

DOEpatents

Tucker; Mark D. , Comstock; Robert H.

2007-10-16

A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator, a sorbent additive, and water. The highly adsorbent, water-soluble sorbent additive (e.g., sorbitol or mannitol) is used to "dry out" one or more liquid ingredients, such as the liquid bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate) and convert the activator into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

Lacrain: the first antimicrobial peptide from the body extract of the Brazilian centipede Scolopendra viridicornis.

PubMed

Chaparro, E; da Silva, P I

2016-09-01

Antimicrobial activities have previously been described by traditional Eastern medicine in Chilopoda body extracts, but until now no bioactive peptides have been described. In this study, a novel antimicrobial peptide, lacrain, was isolated from the body extract of the Brazilian Chilopoda Scolopendra viridicornis. The peptide was isolated by reverse-phase high-performance liquid chromatography (RP-HPLC). Its activity was tested using a liquid growth inhibition assay and the peptide was characterised using mass spectrometry. Lacrain has a sequence composed of eight amino acid residues and a molecular mass of 925.5 Da. A synthetic peptide of the native lacrain had identical characteristics to those of the isolated material, confirming its sequence. The synthetic peptide was active only against Gram-negative bacteria, showing strong bactericidal activity. Moreover, the peptide did not present haemolytic activity against human erythrocytes. Lacrain represents a novel molecule with powerful antibacterial activity that could be used as a new template for the development of drugs against clinically resistant bacterial strains. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Amorphous silicon thin-film transistor active-matrix for reflective cholesteric liquid crystal displays

NASA Astrophysics Data System (ADS)

Nahm, Jeong-Yeop

Reflective cholesteric liquid crystal displays (Ch-LCDs) have advantages, such as, high brightness, low power consumption, and wide viewing angle, since they do not need any polarizer, color filter, and backlight. Furthermore, due to their bistability Ch-LCDs can retain their images virtually forever without additional power consumption. But conventional passive-matrix addressing of Ch-LCDs allows only a slow image updating speed. Active-matrix addressing should allow fast image updating or video-rate operation. However, because the threshold voltage of cholesteric, liquid crystal is high (>20V), the switching devices for active-matrix addressing should satisfy required characteristics even under high bias conditions. In order to investigate the applicability of hydrogenated amorphous silicon thin film transistors (a-Si:H TFTs) for the switching devices of active-matrix (AM) Ch-LCDs, the characteristics of conventional and gate offset high voltage a-Si:H TTFs were examined under high bias conditions. And it was concluded that high OFF-current of conventional a-Si:H TFTs and low ON-current of gate offset high voltage a-Si:H TFTs were main problems for reflective AM Ch-LCD applications. In order to improve the TFT characteristics under high bias conditions, we propose two new a-Si:H TFT structures called gate planarized (GP) and buried field plate (BFP) high voltage a-Si:H TFTs. Firstly, in the GP a-Si:H TFTs, we used a thick spin-coated benzocyclobutene (BCB) layer beneath a thin hydrogenated amorphous silicon nitride (a-SiNx:H) layer for gate insulator. The GP a-Si:H TFT showed normal TFT characteristic up to VGS = VDS = ˜100 V without any device failure. But TFT ON-current of GP a-Si:H TFT was reduced due to the introduction of the thick low dielectric BCB layer. Secondly, in the BFP a-Si:H TFT, an offset region and a buried field plate were introduced between the drain/source and gate electrodes to reduce the electric field in the pinch-off region. For this BFP a-Si:H TFT, a low OFF-current (1.04 pA) and a high ON/OFF-current ratio (5.68 x 106) up to VGS = VDS = ˜30 V were obtained. Based on our a-Si:H TFTs studies, we designed an a-Si:H TFT active-matrix panel and fabricated the AM Ch-LCDs either by optimizing a-Si:H TFT processing or adopting the GP a-Si:H TFT technology. The fabricated a-Si:H TFT active-matrix panels can be operated at the voltage of 50 and 60V, applied to the data and gate lines, respectively. With the a-Si:H TFT active-matrix panels, the AM Ch-LCDs were fabricated and operated with the frame rate of 60 Hz and the maximum contrast ratio of ˜30.

Purification of charybdotoxine, a specific inhibitor of the high-conductance Ca/sup 2 +/-activated K/sup +/ channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, C.; Phillips, M.; Miller, C.

1986-11-05

Charybdotoxim is a high-affinity specific inhibitor of the high-conductance Ca/sup 2 +/-activated K/sup +/ channel found in the plasma membranes of many vertebrate cell types. Using Ca/sup 2 +/-activated K/sup +/ channels reconstituted into planar lipid bilayer membranes as an assay, the authors have purified the toxin from the venom of the scorpion Leiurus quinquestriatus by a two-step procedure involving chromatofocusing on SP-Sephadex, followed by reversed-phase high-performance liquid chromatography. Charybdotoxin is shown to be a highly basic protein with a mass of 10 kDa. Under the standard assay conditions, the purified toxin inhibits the Ca/sup 2 +/-activated K/sup +/ channelmore » with an apparent dissociation constant of 3.5 nM. The protein is unusually stable, with inhibitory potency being insensitive to boiling or exposure to organic solvents. The toxin's activity is sensitive to chymotrypsin treatment and to acylation of lysine groups. The protein may be radioiodinated without loss of activity.« less

Controllable Broadband Optical Transparency and Wettability Switching of Temperature-Activated Solid/Liquid-Infused Nanofibrous Membranes.

PubMed

Manabe, Kengo; Matsubayashi, Takeshi; Tenjimbayashi, Mizuki; Moriya, Takeo; Tsuge, Yosuke; Kyung, Kyu-Hong; Shiratori, Seimei

2016-09-29

Inspired by biointerfaces, such as the surfaces of lotus leaves and pitcher plants, researchers have developed innovative strategies for controlling surface wettability and transparency. In particular, great success has been achieved in obtaining low adhesion and high transmittance via the introduction of a liquid layer to form liquid-infused surfaces. Furthermore, smart surfaces that can change their surface properties according to external stimuli have recently attracted substantial interest. As some of the best-performing smart surface materials, slippery liquid-infused porous surfaces (SLIPSs), which are super-repellent, demonstrate the successful achievement of switchable adhesion and tunable transparency that can be controlled by a graded mechanical stimulus. However, despite considerable efforts, producing temperature-responsive, super-repellent surfaces at ambient temperature and pressure remains difficult because of the use of nonreactive lubricant oil as a building block in previously investigated repellent surfaces. Therefore, the present study focused on developing multifunctional materials that dynamically adapt to temperature changes. Here, we demonstrate temperature-activated solidifiable/liquid paraffin-infused porous surfaces (TA-SLIPSs) whose transparency and control of water droplet movement at room temperature can be simultaneously controlled. The solidification of the paraffin changes the surface morphology and the size of the light-transmission inhibitor in the lubricant layer; as a result, the control over the droplet movement and the light transmittance at different temperatures is dependent on the solidifiable/liquid paraffin mixing ratio. Further study of such temperature-responsive, multifunctional systems would be valuable for antifouling applications and the development of surfaces with tunable optical transparency for innovative medical applications, intelligent windows, and other devices.

78 FR 11273 - Agency Information Collection Activities; Information Collection Renewal; Comment Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

... Activities; Information Collection Renewal; Comment Request; Funding and Liquidity Risk Management AGENCY... and Liquidity Risk Management.'' DATES: Comments must be received by April 16, 2013. ADDRESSES... information collection: Title of Information Collection: Funding and Liquidity Risk Management. OMB Control No...

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

DOE PAGES

Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J.; ...

2017-12-27

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme productionmore » host before they could be considered a viable alternative to current commercial cellulases. Aspergillus Niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. Niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. Niger and Escherichia coli. Finally, this comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. Niger is equivalent, suggesting that A. Niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.« less

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J.

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme productionmore » host before they could be considered a viable alternative to current commercial cellulases. Aspergillus Niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. Niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. Niger and Escherichia coli. Finally, this comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. Niger is equivalent, suggesting that A. Niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.« less

Optimization of ultrasound-assisted hydroalcoholic extraction of phenolic compounds from walnut leaves using response surface methodology.

PubMed

Nour, Violeta; Trandafir, Ion; Cosmulescu, Sina

2016-10-01

Context Walnut leaves are highly appreciated for their pharmacological effects and therapeutic properties which are mainly attributed to their high content of phenolic compounds. Objective This study optimizes ultrasound assisted hydroalcoholic extraction (UAE) of phenolic compounds from dried walnut leaves by the maximization of total phenolics content (TPC) and total flavanoids content (TFC) of the extracts. Materials and methods Optimal conditions with regard to ethanol concentration (X1: 12.17-95.83% v/v), extraction time (X2: 8.17-91.83 min) and liquid-to-solid ratio (X3: 4.96-25.04 v/w) were identified using central composite design combined with response surface methodology. A high-performance liquid chromatography method with diode-array detection was used to quantify phenolic acids (gallic, vanillic, chlorogenic, caffeic, syringic, p-coumaric, ferulic, sinapic, salicylic, ellagic and trans-cinnamic), flavonoids (catechin, epicatechin, rutin, myricetin and quercetin) and juglone in the extracts. Results Liquid-to-solid ratio and ethanol concentration proved to be the primary factors affecting the extraction efficiency. The maximum predicted TPC, under the optimized conditions (61% ethanol concentration, 51.28 min extraction time and 4.96 v/w liquid-to-solid ratio) was 10125.4 mg gallic acid equivalents per liter while maximum TFC (2925 mg quercetin equivalents per liter) occurred at 67.83% ethanol concentration, 4.96 v/w liquid-to-solid ratio and 49.37 min extraction time. High significant correlations were found between antioxidant activity and both TPC (R(2 )=( )0.81) and TFC (R(2 )=( )0.78). Discussion and conclusion Extracts very rich in polyphenols could be obtained from walnut leaves by using UAE, aimed at preparing dietary supplements, nutraceuticals or functional food ingredients.

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

PubMed Central

Lynn, Jed; Sibert, Stephanie J.; Srikrishnan, Sneha; Phatale, Pallavi; Feldman, Taya; Guenther, Joel M.; Hiras, Jennifer; Tran, Yvette Thuy An; Singer, Steven W.; Adams, Paul D.; Sale, Kenneth L.; Simmons, Blake A.; Baker, Scott E.; Magnuson, Jon K.; Gladden, John M.

2017-01-01

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry. PMID:29281693

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger.

PubMed

Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J; Srikrishnan, Sneha; Phatale, Pallavi; Feldman, Taya; Guenther, Joel M; Hiras, Jennifer; Tran, Yvette Thuy An; Singer, Steven W; Adams, Paul D; Sale, Kenneth L; Simmons, Blake A; Baker, Scott E; Magnuson, Jon K; Gladden, John M

2017-01-01

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.

Virantmycin, a new antiviral antibiotic produced by a strain of Streptomyces.

PubMed

Nakagawa, A; Iwai, Y; Hashimoto, H; Miyazaki, N; Oiwa, R; Takahashi, Y; Hirano, A; Shibukawa, N; Kojima, Y; Omura, S

1981-11-01

Virantmycin, a novel chlorine-containing antiviral antibiotic, has been isolated from Streptomyces nitrosporeus No. AM-2722. The active substance in culture broth is isolated as colorless needles by solvent extraction followed by high performance liquid chromatography on silicic acid. The molecular formula is C19H26NO3Cl (molecular weight 351) from the elemental analysis and mass spectrum. The antibiotic possesses antifungal activity and potent inhibitory activity against various RNA and DNA viruses.

Method and apparatus using an active ionic liquid for algae biofuel harvest and extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.

The invention relates to use of an active ionic liquid to dissolve algae cell walls. The ionic liquid is used to, in an energy efficient manner, dissolve and/or lyse an algae cell walls, which releases algae constituents used in the creation of energy, fuel, and/or cosmetic components. The ionic liquids include ionic salts having multiple charge centers, low, very low, and ultra low melting point ionic liquids, and combinations of ionic liquids. An algae treatment system is described, which processes wet algae in a lysing reactor, separates out algae constituent products, and optionally recovers the ionic liquid in an energymore » efficient manner.« less

Research on major antitumor active components in Zi-Cao-Cheng-Qi decoction based on hollow fiber cell fishing with high performance liquid chromatography.

PubMed

Li, Miaomiao; Hu, Shuang; Chen, Xuan; Wang, Runqin; Bai, Xiaohong

2018-02-05

Hollow fiber cell fishing (HFCF) based on hepatoma HepG-2 cells, human renal tubular ACHN cells or human cervical carcinoma HeLa cells, coupled with high-performance liquid chromatography (HPLC), was developed and employed to research the major active components in Zi-Cao-Cheng-Qi decoction both in vitro and in vivo. The research showed that the active components, such as hesperidin, magnolol, honokiol, shikonin, emodin and β,β'-dimethylacrylshikonin were screened out by HFCF based on the cancer cells in vitro, furthermore they can be absorbed into blood and reach in the target organ, and some of the active components can be fished by the cells and maintain effective concentrations. Before application of HFCF with HPLC, cell growth state, cell survival rate, positive effect on screening results binding between active centers on the fiber and target components, repeatability of retention times and relative peak areas of the target analytes were analysed and investigated. In short, HFCF with HPLC is a simple, inexpensive, effective, and reliable method that can be used in researching active components from traditional Chinese medicine (TCM) and its formula both in vitro and in vivo, elucidating preliminarily the TCM characteristics of multiple components and multiple targets, laying a foundation for expounding the antitumor efficacy material basis in TCM. Copyright © 2017 Elsevier B.V. All rights reserved.

Incorporation of ionic liquid into porous polymer monoliths to enhance the separation of small molecules in reversed-phase high-performance liquid chromatography.

PubMed

Wang, Jiafei; Bai, Ligai; Wei, Zhen; Qin, Junxiao; Ma, Yamin; Liu, Haiyan

2015-06-01

An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed-phase high-performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high-performance liquid chromatography. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ion transport properties of magnesium bromide/dimethyl sulfoxide non-aqueous liquid electrolyte

PubMed Central

Sheha, E.

2015-01-01

Nonaqueous liquid electrolyte system based dimethyl sulfoxide DMSO and magnesium bromide (MgBr2) is synthesized via ‘Solvent-in-Salt’ method for the application in magnesium battery. Optimized composition of MgBr2/DMSO electrolyte exhibits high ionic conductivity of 10−2 S/cm at ambient temperature. This study discusses different concentrations from 0 to 5.4 M of magnesium salt, representing low, intermediate and high concentrations of magnesium salt which are examined in frequency dependence conductivity studies. The temperature dependent conductivity measurements have also been carried out to compute activation energy (Ea) by least square linear fitting of Arrhenius plot: ‘log σ − 1/T. The transport number of Mg2+ ion determined by means of a combination of d.c. and a.c. techniques is ∼0.7. A prototype cell was constructed using nonaqueous liquid electrolyte with Mg anode and graphite cathode. The Mg/graphite cell shows promising cycling. PMID:26843967

A search for two types of transverse excitations in liquid polyvalent metals at ambient pressure: An ab initio molecular dynamics study of collective excitations in liquid Al, Tl and Ni

NASA Astrophysics Data System (ADS)

Bryk, Taras; Demchuk, Taras; Jakse, Noël; Wax, Jean-François

2018-02-01

Recent findings of pressure-induced emergence of unusual high-frequency contribution to transverse current spectral functions in several simple liquid metals at high pressures raised a question whether similar features can be observed in liquid metals at ambient conditions. We report here analysis of ab initio molecular dynamics-derived longitudinal (L) and transverse (T) current spectral functions and corresponding dispersions of collective excitations in liquid polyvalent metals Al, Tl, Ni. We have not found evidences of the second branch of high-frequency transverse modes in liquid Al and Ni, while in the case of liquid Tl they were clearly present in transverse dynamics. The vibrational density of states for liquid Tl has a pronounced high-frequency shoulder, which is located right in the frequency range of the second high-frequency transverse branch, while for liquid Al and Ni the vibrational density of states has only a weak indication of possible high-frequency shoulder. The origin of specific behavior of transverse excitations in liquid Tl is discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Renbaum-Wolff, Lindsay; Song, Mijung; Marcolli, Claudia

Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. In order to predict the role of these particles in climate, visibility and atmospheric chemistry, information on particle phase state (i.e., single liquid, two liquids and solid) is needed. Our paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated in the laboratory using optical microscopy and theoretically using a thermodynamic model at 290 K and for relative humidities ranging from < 0.5 to 100%. In the laboratory studies, a single phase was observed frommore » 0 to 95% relative humidity (RH) while two liquid phases were observed above 95% RH. For increasing RH, the mechanism of liquid–liquid phase separation (LLPS) was spinodal decomposition. The RH range over which two liquid phases were observed did not depend on the direction of RH change. In the modeling studies, the SOM took up very little water and was a single organic-rich phase at low RH values. At high RH, the SOM underwent LLPS to form an organic-rich phase and a water-rich phase, consistent with the laboratory studies. The presence of LLPS at high RH values can have consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima were observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. Recently researchers have observed inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation (i.e., hygroscopic parameters measured below water saturation were inconsistent with hygroscopic parameters measured above water saturation). Furthermore, the work presented here illustrates that such inconsistencies are expected for systems with LLPS when the water uptake at subsaturated conditions represents the hygroscopicity of an organic-rich phase while the barrier for CCN activation can be determined by the second maximum in the Köhler curve when the particles are water rich.« less

Expression of Aspergillus niger CAZymes is determined by compositional changes in wheat straw generated by hydrothermal or ionic liquid pretreatments.

PubMed

Daly, Paul; van Munster, Jolanda M; Blythe, Martin J; Ibbett, Roger; Kokolski, Matt; Gaddipati, Sanyasi; Lindquist, Erika; Singan, Vasanth R; Barry, Kerrie W; Lipzen, Anna; Ngan, Chew Yee; Petzold, Christopher J; Chan, Leanne Jade G; Pullan, Steven T; Delmas, Stéphane; Waldron, Paul R; Grigoriev, Igor V; Tucker, Gregory A; Simmons, Blake A; Archer, David B

2017-01-01

The capacity of fungi, such as Aspergillus niger, to degrade lignocellulose is harnessed in biotechnology to generate biofuels and high-value compounds from renewable feedstocks. Most feedstocks are currently pretreated to increase enzymatic digestibility: improving our understanding of the transcriptomic responses of fungi to pretreated lignocellulosic substrates could help to improve the mix of activities and reduce the production costs of commercial lignocellulose saccharifying cocktails. We investigated the responses of A. niger to untreated, ionic liquid and hydrothermally pretreated wheat straw over a 5-day time course using RNA-seq and targeted proteomics. The ionic liquid pretreatment altered the cellulose crystallinity while retaining more of the hemicellulosic sugars than the hydrothermal pretreatment. Ionic liquid pretreatment of straw led to a dynamic induction and repression of genes, which was correlated with the higher levels of pentose sugars saccharified from the ionic liquid-pretreated straw. Hydrothermal pretreatment of straw led to reduced levels of transcripts of genes encoding carbohydrate-active enzymes as well as the derived proteins and enzyme activities. Both pretreatments abolished the expression of a large set of genes encoding pectinolytic enzymes. These reduced levels could be explained by the removal of parts of the lignocellulose by the hydrothermal pretreatment. The time course also facilitated identification of temporally limited gene induction patterns. The presented transcriptomic and biochemical datasets demonstrate that pretreatments caused modifications of the lignocellulose, to both specific structural features as well as the organisation of the overall lignocellulosic structure, that determined A. niger transcript levels. The experimental setup allowed reliable detection of substrate-specific gene expression patterns as well as hitherto non-expressed genes. Our data suggest beneficial effects of using untreated and IL-pretreated straw, but not HT-pretreated straw, as feedstock for CAZyme production.

21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...

21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...

21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...

21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...

21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...

Isolation, Purification, and Characterization of Five Active Diketopiperazine Derivatives from Endophytic Streptomyces SUK 25 with Antimicrobial and Cytotoxic Activities.

PubMed

Alshaibani, Muhanna; Zin, Noraziah; Jalil, Juriyati; Sidik, Nik; Ahmad, Siti Junaidah; Kamal, Nurkhalida; Edrada-Ebel, Ruangelie

2017-07-28

In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as cyclo -( L -Val- L -Pro), cyclo -( L -Leu- L -Pro), cyclo -( L -Phe- L -Pro), cyclo -( L -Val- L -Phe), and N -(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus , with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.

Cellulose Breakdown

ERIC Educational Resources Information Center

Greenler, John; Nye, Leith; Tangen, Travis

2014-01-01

Production of liquid fuels such as ethanol from fibrous plant biomass could potentially be a significant sustainable component of the U.S. energy portfolio. Engineers and scientists are actively researching this area, and high school students can engage in this contemporary inquiry process by experimenting with different types of biomass, varying…

Ultrasound-assisted enzymatic extraction and antioxidant activity of polysaccharides from pumpkin (Cucurbita moschata).

PubMed

Wu, Hao; Zhu, Junxiang; Diao, Wenchao; Wang, Chengrong

2014-11-26

An efficient ultrasound-assisted enzymatic extraction (UAEE) of Cucurbita moschata polysaccharides (CMCP) was established and the CMCP antioxidant activities were studied. The UAEE operating parameters (extraction temperature, ultrasonic power, pH, and liquid-to-material ratio) were optimized using the central composite design (CCD) and the mass transfer kinetic study in UAEE procedure was used to select the optimal extraction time. Enzymolysis and ultrasonication that were simultaneously conducted was selected as the UAEE synergistic model and the optimum extraction conditions with a maximum polysaccharide yield of 4.33 ± 0.15% were as follows: extraction temperature, 51.5 °C; ultrasonic power, 440 W; pH, 5.0; liquid-to-material ratio, 5.70:1 mL/g; and extraction time, 20 min. Evaluation of the antioxidant activity in vitro suggested that CMCP has good potential as a natural antioxidant used in the food or medicine industry because of their high reducing power and positive radical scavenging activity for DPPH radical. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flavonoid profile and antioxidant activities of methanolic extract of Hyparrhenia hirta (L.) Stapf.

PubMed

Bouaziz-Ketata, Hanen; Zouari, Nabil; Ben Salah, Hichem; Rafrafi, Moez; Zeghal, Najiba

2015-04-01

In this study, we report isolation of flavonoids, viz., 3-O-methylquercetin, tangeritin, luteolin-7-O-glucoside, luteolin, apigenin-7-O-glucoside, apigenin-8-C-glucoside, luteolin-8-C-glucoside, luteolin-6-C-glucoside, diosmetin and catechin from the methanolic extract of Hyparrhenia hirta employing high performance liquid chromatography and liquid chromatography-electrospray ionization-tandem mass spectrometry. The total phenolic content of H. hirta extract was 105.58 ± 0.1 mg gallic acid equivalents/g of plant extract while the total flavonoid content was 45.20 ± 0.2 mg quercetin equivalents/g of plant extract and the total condensed tannin were 72.35 ± 0.7 mg catechin equivalents/g of plant extract by reference to standard curve. The antioxidant activity was assayed through the antioxidant capacity by phosphomolybdenum assay, the reducing power assay and the radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl method. The extract showed dose dependant activity in all the three assays.

Modeling Gas-Particle Partitioning of SOA: Effects of Aerosol Physical State and RH

NASA Astrophysics Data System (ADS)

Zuend, A.; Seinfeld, J.

2011-12-01

Aged tropospheric aerosol particles contain mixtures of inorganic salts, acids, water, and a large variety of organic compounds. In liquid aerosol particles non-ideal mixing of all species determines whether the condensed phase undergoes liquid-liquid phase separation or whether it is stable in a single mixed phase, and whether it contains solid salts in equilibrium with their saturated solution. The extended thermodynamic model AIOMFAC is able to predict such phase states by representing the variety of organic components using functional groups within a group-contribution concept. The number and composition of different condensed phases impacts the diversity of reaction media for multiphase chemistry and the gas-particle partitioning of semivolatile species. Recent studies show that under certain conditions biogenic and other organic-rich particles can be present in a highly viscous, semisolid or amorphous solid physical state, with consequences regarding reaction kinetics and mass transfer limitations. We present results of new gas-particle partitioning computations for aerosol chamber data using a model based on AIOMFAC activity coefficients and state-of-the-art vapor pressure estimation methods. Different environmental conditions in terms of temperature, relative humidity (RH), salt content, amount of precursor VOCs, and physical state of the particles are considered. We show how modifications of absorptive and adsorptive gas-particle mass transfer affects the total aerosol mass in the calculations and how the results of these modeling approaches compare to data of aerosol chamber experiments, such as alpha-pinene oxidation SOA. For a condensed phase in a mixed liquid state containing ammonium sulfate, the model predicts liquid-liquid phase separation up to high RH in case of, on average, moderately hydrophilic organic compounds, such as first generation oxidation products of alpha-pinene. The computations also reveal that treating liquid phases as ideal mixtures substantially overestimates the SOA mass, especially at high relative humidity.

Solvent-resistant sol-gel polydimethyldiphenylsiloxane coating for on-line hyphenation of capillary microextraction with high-performance liquid chromatography.

PubMed

Segro, Scott S; Malik, Abdul

2008-09-26

A sol-gel polydimethyldiphenylsiloxane (PDMDPS) coating was developed for capillary microextraction on-line hyphenated with high-performance liquid chromatography (HPLC). This coating was created using methyltrimethoxysilane (MTMS) as the sol-gel precursor and di-hydroxy-terminated PDMDPS as the sol-gel active polymer. The methyl and phenyl groups on the sol-gel active polymer and the methyl groups on the sol-gel precursor ultimately turned into pendant groups providing the ability to extract non-polar analytes. A 40-cm segment of 0.25 mm I.D. fused silica capillary containing the sol-gel PDMDPS coating was installed as an external sampling loop in an HPLC injection port. Aqueous samples containing polycyclic aromatic hydrocarbons (PAHs), aromatic compounds, ketones, and aldehydes were passed through this capillary wherein the analytes were extracted by the sol-gel coating. The extracted analytes were then transferred to the HPLC column using isocratic or gradient elution with an acetonitrile/water mobile phase. This capillary demonstrated excellent extraction capability for non-polar (e.g., polycyclic aromatic hydrocarbons and aromatic compounds) as well as moderately polar compounds, such as aromatic amines, ketones, and aldehydes. The test results indicate that PDMDPS can be successfully immobilized into a sol-gel network and that the resulting solvent-resistant sol-gel organic-inorganic hybrid coating can be effectively used for on-line hyphenation of capillary microextraction with high-performance liquid chromatography. The test results also indicate that the sol-gel PDMDPS coated capillary is resistant to high-temperature solvents, making it suitable for applications in high-temperature HPLC. To the best of our knowledge, this is the first report on the creation of a silica-based sol-gel PDMDPS coating used in capillary microextraction on-line hyphenated to HPLC.

A simple and precise method to detect sterol esterification activity of lecithin/cholesterol acyltransferase by high-performance liquid chromatography.

PubMed

Wang, Yu; Wang, Siming; Zhang, Lijiao; Zeng, Jie; Yang, Ruiyue; Li, Hongxia; Tang, Yueming; Chen, Wenxiang; Dong, Jun

2018-02-01

The measurement of lecithin: cholesterol acyltransferase (LCAT, EC 2.3.1.43) activity is important in high-density lipoprotein (HDL) metabolism study and cardiovascular disease (CVD) risk assessment. However, current methods suffer from complex design and preparation of exogenous substrate, low reproducibility, and interference of cofactors. In this study, we developed a simple and precise high performance liquid chromatography (HPLC) method for the measurement of LCAT activity. By using 7-dehydrocholesterol (7-DHC) and 1,2-didecanoyl-sn-glycero-3-phosphocholine(10:0PC) as substrates, and an LCAT activating peptide (P642) as activator and emulsifier, the substrate reagent was easily made by vortex. The substrate reagent was mixed with serum samples (50:1, v/v) and incubated at 37 °C for 1 h. After incubation, the lipid was extracted with hexane and ethanol. With a conjugated double bond and ultraviolet absorption, 7-DHC and its esterification product could be separated and analyzed by a single HPLC run without calibration. LCAT activity was a linear function of the serum sample volume and the intra- and total assay coefficients of variation (CV) less than 2.5% were obtained under the standardized conditions. The substrate reagent was stable, and assay result accurately reflected LCAT activity. LCAT activities in 120 healthy subjects were positively correlated with triglyceride (P < 0.05), fractional esterification rate of HDL cholesterol (FER HDL ) (P < 0.0001), and negatively correlated with apolipoprotein AI (apoAI) (P < 0.05) and HDL cholesterol (HDL-C) (P < 0.001). These results suggest that this method is sensitive, reproducible, and not greatly influenced by serum components and added substances, and will be a useful tool in the lipid metabolism study and the risk assessment of CVD.

Synthetic polymers blend used in the production of high activated carbon for pesticides removals from liquid phase.

PubMed

Belo, Cristóvão Ramiro; Cansado, Isabel Pestana da Paixão; Mourão, Paulo Alexandre Mira

2017-02-01

For the activated carbon (AC) production, we used the most common industrial and consumer solid waste, namely polyethyleneterephthalate (PET), alone or blended with other synthetic polymer such polyacrylonitrile (PAN). By mixing PET, with PAN, an improvement in the yield of the AC production was found and the basic character and some textural and chemical properties were enhanced. The PET-PAN mixture was subjected to carbonisation, with a pyrolysis yield of 31.9%, between that obtained with PET (16.9%) or PAN (42.6%) separately. The AC revealed a high surface area (1400, 1230 and 1117 m 2  g -1 ) and pore volume (0.46, 0.56 and 0.50 cm 3  g -1 ), respectively, for PET, PAN and PET-PAN precursors. Selected ACs were successfully tested for 4-chloro-2-methylphenoxyacetic acid (MCPA) and diuron removal from the liquid phase, showing a higher adsorption capacity (1.7 and 1.2 mmol g -1 , respectively, for MCPA and diuron) and good fits with the Langmuir (PET) and Freundlich equation (PAN and PET-PAN blend). With MCPA, the controlling factor to the adsorption capacity was the porous volume and the average pore size. Concerning diuron, the adsorption was controlled essentially by the external diffusion. A remarkable result is the use of different synthetic polymers wastes, as precursors for the production of carbon materials, with high potential application on the pesticides removals from the liquid phase.

Computing the Viscosity of Supercooled Liquids: Markov Network Model

PubMed Central

Li, Ju; Kushima, Akihiro; Eapen, Jacob; Lin, Xi; Qian, Xiaofeng; Mauro, John C.; Diep, Phong; Yip, Sidney

2011-01-01

The microscopic origin of glass transition, when liquid viscosity changes continuously by more than ten orders of magnitude, is challenging to explain from first principles. Here we describe the detailed derivation and implementation of a Markovian Network model to calculate the shear viscosity of deeply supercooled liquids based on numerical sampling of an atomistic energy landscape, which sheds some light on this transition. Shear stress relaxation is calculated from a master-equation description in which the system follows a transition-state pathway trajectory of hopping among local energy minima separated by activation barriers, which is in turn sampled by a metadynamics-based algorithm. Quantitative connection is established between the temperature variation of the calculated viscosity and the underlying potential energy and inherent stress landscape, showing a different landscape topography or “terrain” is needed for low-temperature viscosity (of order 107 Pa·s) from that associated with high-temperature viscosity (10−5 Pa·s). Within this range our results clearly indicate the crossover from an essentially Arrhenius scaling behavior at high temperatures to a low-temperature behavior that is clearly super-Arrhenius (fragile) for a Kob-Andersen model of binary liquid. Experimentally the manifestation of this crossover in atomic dynamics continues to raise questions concerning its fundamental origin. In this context this work explicitly demonstrates that a temperature-dependent “terrain” characterizing different parts of the same potential energy surface is sufficient to explain the signature behavior of vitrification, at the same time the notion of a temperature-dependent effective activation barrier is quantified. PMID:21464988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Kaisheng; Henan Normal University, School of Chemistry and Environmental Science, Key Laboratory of Green Chemical Media and Reactions, Xin xiang, Henan 453007; Lu, Weiwei

A novel method was proposed for successful fabrication of CuS nanostructures with various morphologies. At the ionic liquids (ILs)-modulated CHCl{sub 3}-H{sub 2}O interface, copper cupferronate [Cu(cup){sub 2}] in CHCl{sub 3} reacted with thiourea in water to generate CuS nanostructures via a solvothermal reaction process. The effects of alkyl chain length of imidazolium cations and nature of anions of the ILs, molar ratio of Cu(cup){sub 2} to thiourea, the reaction temperature and time on the morphology of the products were studied systematically. It was shown that by changing alkyl chain length of imidazolium cations and nature of anions of the ILs,more » CuS nanostructures with various morphologies, including flowers, urchins, large nanodisks and nanoparticles, could be obtained at the liquid-liquid interface, and the ILs played important template roles in directing the formation of CuS nanostructures. Furthermore, the as-prepared CuS samples exhibited high catalytic activity for photodegradation of methyl orange and thermal decomposition of ammonium perchlorate. - Graphical abstract: At the ionic liquids-modulated CHCl{sub 3}-H{sub 2}O interface, the CuS nanostructures with the various morphologies of flowers, urchins, large nanodisks and nanoparticles have been successfully prepared via a solvothermal reaction process. Highlights: Black-Right-Pointing-Pointer The properties of oil-H{sub 2}O interface can be modulated by employing different ILs. Black-Right-Pointing-Pointer The modulated interface has been used to prepare CuS nanostructures with various morphologies. Black-Right-Pointing-Pointer The CuS samples exhibited high catalytic activity for the photodegradation of methyl orange.« less

Toxic effects of ionic liquid 1-octyl-3-methylimidazolium tetrafluoroborate on soil enzyme activity and soil microbial community diversity.

PubMed

Sun, Xi; Zhu, Lusheng; Wang, Jinhua; Wang, Jun; Su, Benying; Liu, Tong; Zhang, Cheng; Gao, Chong; Shao, Yuting

2017-01-01

Ionic liquids (ILs) were considered as "green" solvents and have been used widely because of their excellent properties. But ILs are not as "green" as has been suggested, and the toxic effects of ILs on organisms have been shown in recent years. In the present study, the toxic effects of the IL 1-octyl-3-methylimidazolium tetrafluoroborate ([Omim]BF 4 ) on soil enzyme activity and soil microbial communities at three different concentrations (1.0, 5.0 and 10.0mg/kg) and a control treatment over 40 days of incubation time (sampled on days 10, 20, 30 and 40) were examined under laboratory conditions. The concentrations of [Omim]BF 4 in soils were detected by high performance liquid chromatography (HPLC) and the results indicated that [Omim]BF 4 were maintained stable in the soil during the exposure period. However, the enzyme activity results showed that urease activity was stimulated on day 20 and then decreased after 30 days of incubation. The activity of β-glucosidase was stimulated after 20 days of incubation in both treatment groups. Moreover, both dehydrogenase and acid phosphatase were inhibited at a high level (10.0mg/kg) only on day 20. The analysis of terminal restriction fragment length polymorphism (T-RFLP) revealed that the soil microbial community structures were altered by [Omim]BF 4 and that the soil microbial diversity and evenness of high levels (5.0mg/kg and 10.0mg/kg) treatments were decreased. Moreover, the dominant structure of the microbial communities was not changed by [Omim]BF 4 . Furthermore, the abundance of the ammonia monooxygenase (amoA) genes of both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) was examined using real time polymerase chain reaction (RT-PCR). The results revealed that the copy numbers of the amoA-gene were decreased by [Omim]BF 4 with the 5.0 and 10.0mg/kg treatments. Based on the experiment, we concluded that high levels (5.0 and 10.0mg/kg) of [Omim]BF 4 could have significantly toxic effects on soil enzyme activities and the diversity of the microbial communities. Copyright © 2016 Elsevier Inc. All rights reserved.

Simultaneous quantification of five major active components in capsules of the traditional Chinese medicine ‘Shu-Jin-Zhi-Tong’ by high performance liquid chromatography

PubMed Central

Yang, Xing-Xin; Zhang, Xiao-Xia; Chang, Rui-Miao; Wang, Yan-Wei; Li, Xiao-Ni

2011-01-01

A simple and reliable high performance liquid chromatography (HPLC) method has been developed for the simultaneous quantification of five major bioactive components in ‘Shu-Jin-Zhi-Tong’ capsules (SJZTC), for the purposes of quality control of this commonly prescribed traditional Chinese medicine. Under the optimum conditions, excellent separation was achieved, and the assay was fully validated in terms of linearity, precision, repeatability, stability and accuracy. The validated method was applied successfully to the determination of the five compounds in SJZTC samples from different production batches. The HPLC method can be used as a valid analytical method to evaluate the intrinsic quality of SJZTC. PMID:29403711

High performance liquid chromatography time of flight electrospray ionization mass spectrometry for quantification of sesquiterpenes in Chrysanthemi indici Flos active extract

PubMed Central

Fu, Ling; Wang, Pan; Sun, Yiqun; Wang, Yangyang; Zhao, Jing; Ye, Yuting; Zhang, Yanbin; Bi, Yuefeng

2015-01-01

Background: Chrysanthemi indici Flos, a traditional herbal medicine is used to clearing heat–toxicity, removing the liver fire, and improving eyesight. In our preliminary work, an active extract of CTC in C. An indici Flos with anti-hepatitis B virus and liver protective activity was found by HepG2.2.1.5 test and experiment of protein synthesis in mice's injured liver. In this work, we aimed to study the active faction CTC further by qualitative and quantitative analysis method. Materials and Methods: High performance liquid chromatography time of flight electrospray ionization mass spectrometry (HPLC TOF ESI-MS) analysis method of the CTC was established. Cumambrin A and angeloylcumambrin B in CTC were analyzed by high performance liquid chromatography-ultraviolet-evaporative light scattering detector (HPLC-UV-ELSD) analysis methods. A binary gradient elution program was conducted for chromatographic separation with acetonitrile (A) and ultrapure water (B) as follows: 0–10 min, 42–46% A; 10–20 min, 46–55% A; 20–25 min, 55–60% A; and 25–35 min, 60–75% A. The column temperature and UV wavelength were set at 30°C and 205 nm. Result: Ten constituents including (3R, 5R, 6S, 7S, 10R)-7-(2-hydroxy-2-propyl)-10-methyl-4-methyleneperhy, dronaphthal-ene-3, 5, 6-triol acetone solvate; (+)-edusmance-4, (14)-ene-11, 13-diol; linarin; luteolin; apigenin; tricin; 5, 3’,4’- trimethyl-6,7-dimethoxy flavones; cumambrin A; acacetin; and angeloylcumambrin B in CTC were identified by HPLC TOF ESI-MS. The contents of sesquiterpenes in CTC were decreased by storing years. Conclusions: The results showed that both UV and ELSD methods were feasible, accurate, and the determination results were in good consistency. The contents of two sesquiterpenes decreased with storing years. Two sesquiterpenes could be used as quality control for C. indici flos CTC. PMID:26600718

Ramjets and Ramrockets for Military Applications

DTIC Science & Technology

1982-03-01

course, as shown, a carefully planned development progrme will be necessary. The high reliability which has been demonstrated for the liquid fuelled...space resear6h tes rendered high energy propellants ,a6re interesting. Liquid hydrogen/ liquid oxigen engine - Nowadays, it is a ra,,able high ...feed system, figure 1, includes low and high pressure turbopumps for the liquid hydrogen fuel and liquid oiygen oxidizer. Each-low- pressure fuel

Mechanism and preparation of liquid alkali-free liquid setting accelerator for shotcrete

NASA Astrophysics Data System (ADS)

Qiu, Ying; Ding, Bei; Gan, Jiezhong; Guo, Zhaolai; Zheng, Chunyang; Jiang, Haidong

2017-03-01

A new alkali-free liquid accelerator for shotcrete was prepared through normal temperature drop process by using the nano activated alumina and the modified alcohol amine as the main raw materials. The effect of alkali-free liquid accelerator on the cement setting time and the mechanical properties of mortar, the effect of the penetration strength on the shotcrete rebound were investigated. And the accelerating mechanism of the as-prepared alkali-free liquid accelerator was also analyzed via XRD and SEM characterization methods. The experimental results indicated that the hydration of C3A was accelerated by the polyamine complexation of accelerator, resulting in forming a large number of acicular ettringite and reducing the amount of Ca(OH)2 crystal, which would not affect the later hydration of cement. When the content of alkali-free liquid accelerator was 6%, the initial setting time and final setting time were less than 3min and 8min respectively, and 1d and 28d compressive strength ratios reached 207.6% and 114.2% respectively; beside that, the shotcrete rebound was very low because of the high penetration strength within 30min.

Gold metal liquid-like droplets.

PubMed

Smirnov, Evgeny; Scanlon, Micheál D; Momotenko, Dmitry; Vrubel, Heron; Méndez, Manuel A; Brevet, Pierre-Francois; Girault, Hubert H

2014-09-23

Simple methods to self-assemble coatings and films encompassing nanoparticles are highly desirable in many practical scenarios, yet scarcely any examples of simple, robust approaches to coat macroscopic droplets with continuous, thick (multilayer), reflective and stable liquid nanoparticle films exist. Here, we introduce a facile and rapid one-step route to form films of reflective liquid-like gold that encase macroscopic droplets, and we denote these as gold metal liquid-like droplets (MeLLDs). The present approach takes advantage of the inherent self-assembly of gold nanoparticles at liquid-liquid interfaces and the increase in rates of nanoparticle aggregate trapping at the interface during emulsification. The ease of displacement of the stabilizing citrate ligands by appropriate redox active molecules that act as a lubricating molecular glue is key. Specifically, the heterogeneous interaction of citrate stabilized aqueous gold nanoparticles with the lipophilic electron donor tetrathiafulvalene under emulsified conditions produces gold MeLLDs. This methodology relies exclusively on electrochemical reactions, i.e., the oxidation of tetrathiafulvalene to its radical cation by the gold nanoparticle, and electrostatic interactions between the radical cation and nanoparticles. The gold MeLLDs are reversibly deformable upon compression and decompression and kinetically stable for extended periods of time in excess of a year.

Dynamic crossover in deeply cooled water confined in MCM-41 at 4 kbar and its relation to the liquid-liquid transition hypothesis

NASA Astrophysics Data System (ADS)

Wang, Zhe; Le, Peisi; Ito, Kanae; Leão, Juscelino B.; Tyagi, Madhusudan; Chen, Sow-Hsin

2015-09-01

With quasi-elastic neutron scattering, we study the single-particle dynamics of the water confined in a hydrophilic silica material, MCM-41, at 4 kbar. A dynamic crossover phenomenon is observed at 219 K. We compare this dynamic crossover with the one observed at ambient pressure and find that (a) above the crossover temperature, the temperature dependence of the characteristic relaxation time at ambient pressure exhibits a more evident super-Arrhenius behavior than that at 4 kbar. Especially, at temperatures below about 230 K, the relaxation time at 4 kbar is even smaller than that at ambient pressure. This feature is different from many other liquids. (b) Below the crossover temperature, the Arrhenius behavior found at ambient pressure has a larger activation energy compared to the one found at 4 kbar. We ascribe the former to the difference between the local structure of the low-density liquid (LDL) phase and that of the high-density liquid (HDL) phase, and the latter to the difference between the strength of the hydrogen bond of the LDL and that of the HDL. Therefore, we conclude that the phenomena observed in this paper are consistent with the LDL-to-HDL liquid-liquid transition hypothesis.

Dynamic crossover in deeply cooled water confined in MCM-41 at 4 kbar and its relation to the liquid-liquid transition hypothesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhe; Le, Peisi; Ito, Kanae

With quasi-elastic neutron scattering, we study the single-particle dynamics of the water confined in a hydrophilic silica material, MCM-41, at 4 kbar. A dynamic crossover phenomenon is observed at 219 K. We compare this dynamic crossover with the one observed at ambient pressure and find that (a) above the crossover temperature, the temperature dependence of the characteristic relaxation time at ambient pressure exhibits a more evident super-Arrhenius behavior than that at 4 kbar. Especially, at temperatures below about 230 K, the relaxation time at 4 kbar is even smaller than that at ambient pressure. This feature is different from manymore » other liquids. (b) Below the crossover temperature, the Arrhenius behavior found at ambient pressure has a larger activation energy compared to the one found at 4 kbar. We ascribe the former to the difference between the local structure of the low-density liquid (LDL) phase and that of the high-density liquid (HDL) phase, and the latter to the difference between the strength of the hydrogen bond of the LDL and that of the HDL. Therefore, we conclude that the phenomena observed in this paper are consistent with the LDL-to-HDL liquid-liquid transition hypothesis.« less

Catalytic evaluation on liquid phase oxidation of vanillyl alcohol using air and H2O2 over mesoporous Cu-Ti composite oxide

NASA Astrophysics Data System (ADS)

Saha, Subrata; Hamid, Sharifah Bee Abd; Ali, Tammar Hussein

2017-02-01

A mesoporous, highly crystalline Cu-Ti composite oxide catalyst was prepared via facile, simple and modified solution method varying Cu and Ti ratio for selective liquid phase oxidation of vanillyl alcohol. Various spectroscopic procedures were employed to systematically characterize the catalyst structural and physicochemical properties. The defect chemistry of the catalyst was confirmed from the presence of surface defects revealed through HRTEM imagery between the TiO2 (101) and Cu3TiO4 (012) planes, complemented by the XRD profiling. Further, presence of oxygen vacancy evidenced by O 1s XPS spectra were observed on the catalyst surface. Moreover, the stoichiometry of Cu and Ti in the catalyst synthesis protocol was notably found to be the vital determinant to alter the redox properties of Cu-Ti composite oxide catalyst supported by H2-TPR. O2-TPD analysis. Moreover, a rational investigation was done using different oxidants such as air and H2O2 with variables reaction conditions. The catalyst was active for liquid phase oxidation of vanillyl alcohol to vanillin with performance of 66% conversion and 71% selectivity using H2O2 in base free condition. And also, catalytic activity was significantly improved by 94% conversion with 86% selectivity to vanillin in liquid phase aerobic oxidation at the optimum reaction conditions. To expand the superiority of the catalyst, three times reusability study was also examined with appreciable catalytic activity.

A simple and quantitative liquid culture system to measure megakaryocyte growth using highly purified CFU-MK.

PubMed

Miyazaki, H; Horie, K; Shimada, Y; Kokubo, A; Maeda, E; Inoue, H; Kato, T

1995-10-01

A new and quantitative liquid culture system has been developed to measure the production of megakaryocytes from megakaryocyte progenitor cells (colony-forming units-megakaryocyte [CFU-MK]). The system uses as a target population a glycoprotein (Gp) IIb/IIIa+ subpopulation of rat bone marrow cells previously demonstrated to be highly enriched for CFU-MK. GpIIb/IIIa+ cells were cultured at 5 x 10(4) cells/mL (10(4) cells/well) with test samples in 96-well tissue culture plates for 4 days at 37 degrees C. During the final 3 hours of incubation, the cells were pulsed with [14C]5-hydroxytryptamine creatinine sulfate (14C-serotonin). After incubation, the plates were washed and the cell pellets were lysed with Triton-X 100. The cell lysate was infiltrated into a commercially available solid scintillator and dried, and radioactivity was measured. In this assay system, rat interleukin-3 (IL-3) was found to be the most potent among known cytokines tested. Murine granulocyte-macrophage colony-stimulating factor (GM-CSF), human erythropoietin (Epo), human IL-6, and murine stem cell factor (SCF) each alone stimulated megakaryocyte growth but were much less active than rat IL-3. Plasma of rats rendered thrombocytopenic by injection of monoclonal antirat platelet GpIIb/IIIa antibody exhibited significant activity, and the active protein fractions partially purified from the plasma showed much higher activity, but normal rat plasma had no effect. This liquid culture system allows the measurement of a large number of test samples--including a wide variety of cytokines and unknown growth factors, alone or in combinations--and provides a simple method for evaluating the early proliferative events involving CFU-MK in the megakaryocyte differentiation pathway.

Melting in feldspar-bearing systems to high pressures and the structures of aluminosilicate liquids

NASA Astrophysics Data System (ADS)

Boettcher, Art; Guo, Qiti; Bohlen, Steve; Hanson, Brooks

1984-04-01

To test the possibility that aluminosilicate liquids exhibit pressure-induced transformations, particularly involving changes in the coordination of aluminum, we determined melting relationships for the feldspar-bearing systems NaAlSi3O8-SiO2, KAlSi3O8-SiO2, and CaAl2Si2O8-SiO2 from 1 atm to 25 kbar. Albite and anorthite behave similarly in that they, and presumably liquids of these compositions, transform at high pressures to jadeite, kyanite, corundum, and other structures with aluminum in six-fold coordination, releasing SiO2 component. This results in a large increase in the activity of SiO2 component in the liquid (alqz), which is manifested by a significant decrease in the melting-point depression of albite and of anorthite by the addition of quartz at pressures above ˜15 kbar. In contrast, sanidine does not transform to denser phases at pressures below at least 100 kbar, but it melts incongruently to leucite + SiO2-rich liquid up to ˜ 15 kbar. This produces a relatively large alqz and a small freezing-point depression by quartz below this pressure; the opposite holds above ˜15 kbar. These results support the concept that significant structural changes, including coordination changes in aluminum, occur in magmas in the upper mantle.

On fiber optic probe hydrophone measurements in a cavitating liquid.

PubMed

Zijlstra, Aaldert; Ohl, Claus Dieter

2008-01-01

The measurement of high-pressure signals is often hampered by cavitation activity. The usage of a fiber optic probe hydrophone possesses advantages over other hydrophones, yet when measuring in a cavitating liquid large variations in the signal amplitude are found; in particular when the pressure signal recovers back to positive values. With shadowgraphy the wave propagation and cavity dynamics are imaged and the important contributions of secondary shock waves emitted from collapsing cavitation bubbles are revealed. Interestingly, just adding a small amount of acidic acid reduces the cavitation activity to a large extent. With this treatment an altered primary pressure profile which does not force the cavitation bubbles close to fiber tip into collapse has been found. Thereby, the shot-to-shot variations are greatly reduced.

Development and validation of a highly sensitive liquid chromatography/mass spectrometry method for simultaneous quantification of lenalidomide and flavopiridol in human plasma.

PubMed

Liu, Qing; Farley, Katherine L; Johnson, Amy J; Muthusamy, Natarajan; Hofmeister, Craig C; Blum, Kristie A; Schaaf, Larry J; Grever, Michael R; Byrd, John C; Dalton, James T; Phelps, Mitch A

2008-10-01

Lenalidomide, an immunomodulatory agent, and flavopiridol, a broad cyclin-dependent kinase inhibitor, are active therapies for clinical use in genomic high-risk chronic lymphocytic leukemia. A high-performance liquid chromatographic assay with tandem mass spectrometric detection has been developed to simultaneously quantify lenalidomide and flavopiridol in human and mouse plasma to facilitate their combined clinical development. Samples were prepared by liquid-liquid extraction with acetonitrile (ACN)-containing internal standard, genistein, followed by evaporation of solvent and reconstitution in 95/5 H2O/ACN. Lenalidomide and internal standard were separated by reversed-phase liquid chromatography on a C-18 column using a gradient of H2O and ACN, each with 0.1% formic acid. Atmospheric pressure chemical ionization in positive ion mode with single reaction monitoring on a triple quadrupole mass spectrometer was applied to detect transitions of lenalidomide (260.06 > 149.10) and flavopiridol (402.09 > 341.02). Lower limits of quantification of lenalidomide and flavopiridol were 1 and 0.3 nM, respectively. Recoveries of lenalidomide and flavopiridol from human plasma ranged from 99% to 116% throughout their linear ranges. Within- and between-run precision and accuracy of replicate samples were all less than 15%. This is the most sensitive analytical method reported to date for both lenalidomide and flavopiridol. This sensitivity will enable late terminal phase concentration measurements and accurate pharmacokinetic parameter estimation in a planned clinical trial with lenalidomide and flavopiridol in patients with chronic lymphocytic leukemia.

Hyperprolinemic larvae of the drosophilid fly, Chymomyza costata, survive cryopreservation in liquid nitrogen

PubMed Central

Koštál, Vladimír; Zahradníčková, Helena; Šimek, Petr

2011-01-01

The larva of the drosophilid fly, Chymomyza costata, is probably the most complex metazoan organism that can survive submergence in liquid nitrogen (-196 °C) in a fully hydrated state. We examined the associations between the physiological and biochemical parameters of differently acclimated larvae and their freeze tolerance. Entering diapause is an essential and sufficient prerequisite for attaining high levels of survival in liquid nitrogen (23% survival to adult stage), although cold acclimation further improves this capacity (62% survival). Profiling of 61 different metabolites identified proline as a prominent compound whose concentration increased from 20 to 147 mM during diapause transition and subsequent cold acclimation. This study provides direct evidence for the essential role of proline in high freeze tolerance. We increased the levels of proline in the larval tissues by feeding larvae proline-augmented diets and found that this simple treatment dramatically improved their freeze tolerance. Cell and tissue survival following exposure to liquid nitrogen was evident in proline-fed nondiapause larvae, and survival to adult stage increased from 0% to 36% in proline-fed diapause-destined larvae. A significant statistical correlation was found between the whole-body concentration of proline, either natural or artificial, and survival to the adult stage in liquid nitrogen for diapause larvae. Differential scanning calorimetry analysis suggested that high proline levels, in combination with a relatively low content of osmotically active water and freeze dehydration, increased the propensity of the remaining unfrozen water to undergo a glass-like transition (vitrification) and thus facilitated the prevention of cryoinjury. PMID:21788482

Improvement of imprinting effect of ionic liquid molecularly imprinted polymers by use of a molecular crowding agent.

PubMed

Jia, Man; Yang, Jian; Sun, Ya Kun; Bai, Xi; Wu, Tao; Liu, Zhao Sheng; Aisa, Haji Akber

2018-01-01

We aimed to improve the imprinting effect of ionic liquid molecularly imprinted polymers (MIPs) by use of a molecular crowding agent. The ionic liquid 1-vinyl-3-ethylimidazolium tetrafluoroborate ([VEIm][BF 4 ]) was used as the functional monomer and aesculetin was used as the template molecule in a crowding environment, which was made up of a tetrahydrofuran solution of polystyrene. The ionic liquid MIPs that were prepared in the crowding environment displayed an enhanced imprinting effect. NMR peak shifts of active hydrogen of aesculetin suggested that interaction between the functional monomer and the template could be increased by the use of a crowding agent in the self-assembly process. The retention and selectivity of aesculetin were affected greatly by high molecular crowding, the amount of high molecular weight crowding agent, and the ratio of [VEIm][BF 4 ] to aesculetin. The optimal MIPs were used as solid-phase extraction sorbents to extract aesculetin from Cichorium glandulosum. A calibration curve was obtained with aesculetin concentrations from 0.0005 to 0.05 mg mL -1 (correlation coefficient R 2 of 0.9999, y = 1519x + 0.0923). The limit of quantification was 0.12 μg mL -1 , and the limit of detection was 0.05 μg mL -1 . The absolute recovery of aesculetin was (80 ± 2)% (n = 3), and the purity of aesculetin was (92 ± 0.5)% (n = 5). As a conclusion, molecular crowding is an effective approach to obtain ionic liquid MIPs with high selectivity even in a polar solvent environment.

Hyperprolinemic larvae of the drosophilid fly, Chymomyza costata, survive cryopreservation in liquid nitrogen.

PubMed

Kostál, Vladimír; Zahradnícková, Helena; Šimek, Petr

2011-08-09

The larva of the drosophilid fly, Chymomyza costata, is probably the most complex metazoan organism that can survive submergence in liquid nitrogen (-196 °C) in a fully hydrated state. We examined the associations between the physiological and biochemical parameters of differently acclimated larvae and their freeze tolerance. Entering diapause is an essential and sufficient prerequisite for attaining high levels of survival in liquid nitrogen (23% survival to adult stage), although cold acclimation further improves this capacity (62% survival). Profiling of 61 different metabolites identified proline as a prominent compound whose concentration increased from 20 to 147 mM during diapause transition and subsequent cold acclimation. This study provides direct evidence for the essential role of proline in high freeze tolerance. We increased the levels of proline in the larval tissues by feeding larvae proline-augmented diets and found that this simple treatment dramatically improved their freeze tolerance. Cell and tissue survival following exposure to liquid nitrogen was evident in proline-fed nondiapause larvae, and survival to adult stage increased from 0% to 36% in proline-fed diapause-destined larvae. A significant statistical correlation was found between the whole-body concentration of proline, either natural or artificial, and survival to the adult stage in liquid nitrogen for diapause larvae. Differential scanning calorimetry analysis suggested that high proline levels, in combination with a relatively low content of osmotically active water and freeze dehydration, increased the propensity of the remaining unfrozen water to undergo a glass-like transition (vitrification) and thus facilitated the prevention of cryoinjury.

New on-line separation workflow of microbial metabolites via hyphenation of analytical and preparative comprehensive two-dimensional liquid chromatography.

PubMed

Yan, Xia; Wang, Li-Juan; Wu, Zhen; Wu, Yun-Long; Liu, Xiu-Xiu; Chang, Fang-Rong; Fang, Mei-Juan; Qiu, Ying-Kun

2016-10-15

Microbial metabolites represent an important source of bioactive natural products, but always exhibit diverse of chemical structures or complicated chemical composition with low active ingredients content. Traditional separation methods rely mainly on off-line combination of open-column chromatography and preparative high performance liquid chromatography (HPLC). However, the multi-step and prolonged separation procedure might lead to exposure to oxygen and structural transformation of metabolites. In the present work, a new two-dimensional separation workflow for fast isolation and analysis of microbial metabolites from Chaetomium globosum SNSHI-5, a cytotoxic fungus derived from extreme environment. The advantage of this analytical comprehensive two-dimensional liquid chromatography (2D-LC) lies on its ability to analyze the composition of the metabolites, and to optimize the separation conditions for the preparative 2D-LC. Furthermore, gram scale preparative 2D-LC separation of the crude fungus extract could be performed on a medium-pressure liquid chromatograph×preparative high-performance liquid chromatography system, under the optimized condition. Interestingly, 12 cytochalasan derivatives, including two new compounds named cytoglobosin Ab (3) and isochaetoglobosin Db (8), were successfully obtained with high purity in a short period of time. The structures of the isolated metabolites were comprehensively characterized by HR ESI-MS and NMR. To be highlighted, this is the first report on the combination of analytical and preparative 2D-LC for the separation of microbial metabolites. The new workflow exhibited apparent advantages in separation efficiency and sample treatment capacity compared with conventional methods. Copyright © 2016 Elsevier B.V. All rights reserved.

78 FR 24810 - Agency Information Collection Activities; Information Collection Renewal; Submission for OMB...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-26

... Activities; Information Collection Renewal; Submission for OMB Review: Funding and Liquidity Risk Management... and Liquidity Risk Management.'' The OCC is also giving notice that the collection has been sent to... collection: Title of Information Collection: Funding and Liquidity Risk Management. OMB Control No.: 1557...

Demonstration of a high-intensity neutron source based on a liquid-lithium target for Accelerator based Boron Neutron Capture Therapy.

PubMed

Halfon, S; Arenshtam, A; Kijel, D; Paul, M; Weissman, L; Berkovits, D; Eliyahu, I; Feinberg, G; Kreisel, A; Mardor, I; Shimel, G; Shor, A; Silverman, I; Tessler, M

2015-12-01

A free surface liquid-lithium jet target is operating routinely at Soreq Applied Research Accelerator Facility (SARAF), bombarded with a ~1.91 MeV, ~1.2 mA continuous-wave narrow proton beam. The experiments demonstrate the liquid lithium target (LiLiT) capability to constitute an intense source of epithermal neutrons, for Accelerator based Boron Neutron Capture Therapy (BNCT). The target dissipates extremely high ion beam power densities (>3 kW/cm(2), >0.5 MW/cm(3)) for long periods of time, while maintaining stable conditions and localized residual activity. LiLiT generates ~3×10(10) n/s, which is more than one order of magnitude larger than conventional (7)Li(p,n)-based near threshold neutron sources. A shield and moderator assembly for BNCT, with LiLiT irradiated with protons at 1.91 MeV, was designed based on Monte Carlo (MCNP) simulations of BNCT-doses produced in a phantom. According to these simulations it was found that a ~15 mA near threshold proton current will apply the therapeutic doses in ~1h treatment duration. According to our present results, such high current beams can be dissipated in a liquid-lithium target, hence the target design is readily applicable for accelerator-based BNCT. Copyright © 2015 Elsevier Ltd. All rights reserved.

ON-SITE SOLID-PHASE EXTRACTION AND LABORATORY ...

EPA Pesticide Factsheets

Fragrance materials such as synthetic musks in aqueous samples, are normally determined by gas chromatography/mass spectrometry in the selected ion monitoring (SIM) mode to provide maximum sensitivity after liquid-liquid extraction of I -L samples. Full-scan mass spectra are required to verify that a target analyte has been found by comparison with the mass spectra of fragrance compounds in the NIST mass spectral library. A I -L sample usually provides insufficient analyte for full scan data acquisition. This paper describes an on-site extraction method developed at the U.S. Environmental Protection Agency (USEPA)- Las Vegas Nevada - for synthetic musks from 60 L of wastewater effluent. Such a large sample volume permits high-quality, full-scan mass spectra to be obtained for a wide array of synthetic musks. Quantification of these compounds was achieved from the full-scan data directly, without the need to acquire SIM data. The detection limits obtained with this method are an order of magnitude lower than those obtained from liquid-liquid and other solid phase extraction methods. This method is highly reproducible, and recoveries ranged from 80 to 97% in spiked sewage treatment plant effluent. The high rate of sorbent-sample mass transfer eliminated the need for a methanolic activation step, which reduced extraction time, labor, and solvent use, More samples could be extracted in the field at lower cost. After swnple extraction, the light- weight cartridges ar

NASA Icing Remote Sensing System Comparisons From AIRS II

NASA Technical Reports Server (NTRS)

Reehorst, Andrew L.; Brinker, David J.; Ratvasky, Thomas P.

2005-01-01

NASA has an on-going activity to develop remote sensing technologies for the detection and measurement of icing conditions aloft. A multiple instrument approach is the current emphasis of this activity. Utilizing radar, radiometry, and lidar, a region of supercooled liquid is identified. If the liquid water content (LWC) is sufficiently high, then the region of supercooled liquid cloud is flagged as being an aviation hazard. The instruments utilized for the current effort are an X-band vertical staring radar, a radiometer that measures twelve frequencies between 22 and 59 GHz, and a lidar ceilometer. The radar data determine cloud boundaries, the radiometer determines the sub-freezing temperature heights and total liquid water content, and the ceilometer refines the lower cloud boundary. Data is post-processed with a LabVIEW program with a resultant supercooled LWC profile and aircraft hazard identification. Individual remotely sensed measurements gathered during the 2003-2004 Alliance Icing Research Study (AIRS II) were compared to aircraft in-situ measurements. Comparisons between the remote sensing system s fused icing product and in-situ measurements from the research aircraft are reviewed here. While there are areas where improvement can be made, the cases examined indicate that the fused sensor remote sensing technique appears to be a valid approach.

Ultrasound Velocity Measurement in a Liquid Metal Electrode

PubMed Central

Perez, Adalberto; Kelley, Douglas H.

2015-01-01

A growing number of electrochemical technologies depend on fluid flow, and often that fluid is opaque. Measuring the flow of an opaque fluid is inherently more difficult than measuring the flow of a transparent fluid, since optical methods are not applicable. Ultrasound can be used to measure the velocity of an opaque fluid, not only at isolated points, but at hundreds or thousands of points arrayed along lines, with good temporal resolution. When applied to a liquid metal electrode, ultrasound velocimetry involves additional challenges: high temperature, chemical activity, and electrical conductivity. Here we describe the experimental apparatus and methods that overcome these challenges and allow the measurement of flow in a liquid metal electrode, as it conducts current, at operating temperature. Temperature is regulated within ±2 °C using a Proportional-Integral-Derivative (PID) controller that powers a custom-built furnace. Chemical activity is managed by choosing vessel materials carefully and enclosing the experimental setup in an argon-filled glovebox. Finally, unintended electrical paths are carefully prevented. An automated system logs control settings and experimental measurements, using hardware trigger signals to synchronize devices. This apparatus and these methods can produce measurements that are impossible with other techniques, and allow optimization and control of electrochemical technologies like liquid metal batteries. PMID:26273726

Cubic and Hexagonal Liquid Crystals as Drug Delivery Systems

PubMed Central

Chen, Yulin; Ma, Ping; Gui, Shuangying

2014-01-01

Lipids have been widely used as main constituents in various drug delivery systems, such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, and lipid-based lyotropic liquid crystals. Among them, lipid-based lyotropic liquid crystals have highly ordered, thermodynamically stable internal nanostructure, thereby offering the potential as a sustained drug release matrix. The intricate nanostructures of the cubic phase and hexagonal phase have been shown to provide diffusion controlled release of active pharmaceutical ingredients with a wide range of molecular weights and polarities. In addition, the biodegradable and biocompatible nature of lipids demonstrates the minimum toxicity and thus they are used for various routes of administration. Therefore, the research on lipid-based lyotropic liquid crystalline phases has attracted a lot of attention in recent years. This review will provide an overview of the lipids used to prepare cubic phase and hexagonal phase at physiological temperature, as well as the influencing factors on the phase transition of liquid crystals. In particular, the most current research progresses on cubic and hexagonal phases as drug delivery systems will be discussed. PMID:24995330

Quality Evaluation of Potentilla fruticosa L. by High Performance Liquid Chromatography Fingerprinting Associated with Chemometric Methods.

PubMed

Liu, Wei; Wang, Dongmei; Liu, Jianjun; Li, Dengwu; Yin, Dongxue

2016-01-01

The present study was performed to assess the quality of Potentilla fruticosa L. sampled from distinct regions of China using high performance liquid chromatography (HPLC) fingerprinting coupled with a suite of chemometric methods. For this quantitative analysis, the main active phytochemical compositions and the antioxidant activity in P. fruticosa were also investigated. Considering the high percentages and antioxidant activities of phytochemicals, P. fruticosa samples from Kangding, Sichuan were selected as the most valuable raw materials. Similarity analysis (SA) of HPLC fingerprints, hierarchical cluster analysis (HCA), principle component analysis (PCA), and discriminant analysis (DA) were further employed to provide accurate classification and quality estimates of P. fruticosa. Two principal components (PCs) were collected by PCA. PC1 separated samples from Kangding, Sichuan, capturing 57.64% of the variance, whereas PC2 contributed to further separation, capturing 18.97% of the variance. Two kinds of discriminant functions with a 100% discrimination ratio were constructed. The results strongly supported the conclusion that the eight samples from different regions were clustered into three major groups, corresponding with their morphological classification, for which HPLC analysis confirmed the considerable variation in phytochemical compositions and that P. fruticosa samples from Kangding, Sichuan were of high quality. The results of SA, HCA, PCA, and DA were in agreement and performed well for the quality assessment of P. fruticosa. Consequently, HPLC fingerprinting coupled with chemometric techniques provides a highly flexible and reliable method for the quality evaluation of traditional Chinese medicines.

Quality Evaluation of Potentilla fruticosa L. by High Performance Liquid Chromatography Fingerprinting Associated with Chemometric Methods

PubMed Central

Liu, Wei; Wang, Dongmei; Liu, Jianjun; Li, Dengwu; Yin, Dongxue

2016-01-01

The present study was performed to assess the quality of Potentilla fruticosa L. sampled from distinct regions of China using high performance liquid chromatography (HPLC) fingerprinting coupled with a suite of chemometric methods. For this quantitative analysis, the main active phytochemical compositions and the antioxidant activity in P. fruticosa were also investigated. Considering the high percentages and antioxidant activities of phytochemicals, P. fruticosa samples from Kangding, Sichuan were selected as the most valuable raw materials. Similarity analysis (SA) of HPLC fingerprints, hierarchical cluster analysis (HCA), principle component analysis (PCA), and discriminant analysis (DA) were further employed to provide accurate classification and quality estimates of P. fruticosa. Two principal components (PCs) were collected by PCA. PC1 separated samples from Kangding, Sichuan, capturing 57.64% of the variance, whereas PC2 contributed to further separation, capturing 18.97% of the variance. Two kinds of discriminant functions with a 100% discrimination ratio were constructed. The results strongly supported the conclusion that the eight samples from different regions were clustered into three major groups, corresponding with their morphological classification, for which HPLC analysis confirmed the considerable variation in phytochemical compositions and that P. fruticosa samples from Kangding, Sichuan were of high quality. The results of SA, HCA, PCA, and DA were in agreement and performed well for the quality assessment of P. fruticosa. Consequently, HPLC fingerprinting coupled with chemometric techniques provides a highly flexible and reliable method for the quality evaluation of traditional Chinese medicines. PMID:26890416

The investigation of critical burning of fuel droplets

NASA Technical Reports Server (NTRS)

Allison, C. B.; Canada, G. S.; Faeth, G. M.

1973-01-01

The combustion and evaporation of liquid fuels at high pressures were investigated. Particular emphasis was placed on conditions where the liquid surface approaches the thermodynamic critical point during combustion. The influence of transient effects on a burning liquid fuel was also investigated through both analysis and measurements of the response of liquid monopropellant combustion to imposed pressure oscillations. Work was divided into four phases (1) Droplet combustion at high pressures, which consider both measurement and analysis of the porous sphere burning rate of liquids in a natural convection environment at elevated pressure. (2) High pressure droplet burning in combustion gases, which involved steady burning and evaporation of liquids from porous spheres in a high pressure environment that simulates actual combustion chamber conditions. (3) Liquid strand combustion, which considered the burning rate, the state of the liquid surface and the liquid phase temperature distribution of a burning liquid monopropellant column over a range of pressures. (4) Oscillatory combustion, which was a theoretical and experimental investigation of the response of a burning liquid monopropellant to pressure oscillations.

Temperature-Responsive Luminescent Solar Concentrators: Tuning Energy Transfer in a Liquid Crystalline Matrix.

PubMed

Sol, Jeroen A H P; Dehm, Volker; Hecht, Reinhard; Würthner, Frank; Schenning, Albertus P H J; Debije, Michael G

2018-01-22

Temperature-responsive luminescent solar concentrators (LSCs) have been fabricated in which the Förster resonance energy transfer (FRET) between a donor-acceptor pair in a liquid crystalline solvent can be tuned. At room temperatures, the perylene bisimide (PBI) acceptor is aggregated and FRET is inactive; while after heating to a temperature above the isotropic phase of the liquid crystal solvent, the acceptor PBI completely dissolves and FRET is activated. This unusual temperature control over FRET was used to design a color-tunable LSC. The device has been shown to be highly stable towards consecutive heating and cooling cycles, making it an appealing device for harvesting otherwise unused solar energy. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

PC programs for the prediction of the linear stability behavior of liquid propellant propulsion systems and application to current MSFC rocket engine test programs, volume 1

NASA Technical Reports Server (NTRS)

Doane, George B., III; Armstrong, W. C.

1990-01-01

Research on propulsion stability (chugging and acoustic modes), and propellant valve control was investigated. As part of the activation of the new liquid propulsion test facilities, it is necessary to analyze total propulsion system stability. To accomplish this, several codes were built to run on desktop 386 machines. These codes enable one to analyze the stability question associated with the propellant feed systems. In addition, further work was adapted to this computing environment and furnished along with other codes. This latter inclusion furnishes those interested in high frequency oscillatory combustion behavior (that does not couple to the feed system) a set of codes for study of proposed liquid rocket engines.

Strong Aggregation-Induced CPL Response Promoted by Chiral Emissive Nematic Liquid Crystals (N*-LCs).

PubMed

Li, Xiaojing; Li, Qian; Wang, Yuxiang; Quan, Yiwu; Chen, Dongzhong; Cheng, Yixiang

2018-05-29

In this paper we designed a kind of aggregation-induced emission (AIE) chiral fluorescence emitters (R/S-BINOL-CN enantiomers) in the aggregate state. Chiral emissive nematic liquid crystals (N*-LCs) prepared by doping this kind of AIE-active R/S-BINOL-CN enantiomers into a common achiral nematic liquid crystal (N-LC, E7) can self-assemble as the regularly planar Grandjean texture leading to high luminescence dissymmetry factor (glum) of aggregation-induced circularly polarized luminescence (AI-CPL) signal up to 0.41, which can be attributed to dipolar interactions from polar cyano groups and π-π interactions between binaphthyl moiety of the dopant R/S-BINOL-CN and biphenyl group of the host molecules (E7). © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flame Acceleration and Transition to Detonation in High-Speed Turbulent Combustion

DTIC Science & Technology

2016-12-21

Turbulent Combustion 1. Introduction to the Challenge Problem The importance of high-speed t urbulent combustion of gas mixtures and sprays is dif...engines, gas turbines, various types of jet engines, and some rocket engines . On the other hand , preventing high-speed combustion is critical for...the safety of any human activities that involve handling of po- t entially explosive gases or volatile liquids . Thus, the development of more fuel

JTEC panel on display technologies in Japan

NASA Technical Reports Server (NTRS)

Tannas, Lawrence E., Jr.; Glenn, William E.; Credelle, Thomas; Doane, J. William; Firester, Arthur H.; Thompson, Malcolm

1992-01-01

This report is one in a series of reports that describes research and development efforts in Japan in the area of display technologies. The following are included in this report: flat panel displays (technical findings, liquid crystal display development and production, large flat panel displays (FPD's), electroluminescent displays and plasma panels, infrastructure in Japan's FPD industry, market and projected sales, and new a-Si active matrix liquid crystal display (AMLCD) factory); materials for flat panel displays (liquid crystal materials, and light-emissive display materials); manufacturing and infrastructure of active matrix liquid crystal displays (manufacturing logistics and equipment); passive matrix liquid crystal displays (LCD basics, twisted nematics LCD's, supertwisted nematic LCD's, ferroelectric LCD's, and a comparison of passive matrix LCD technology); active matrix technology (basic active matrix technology, investment environment, amorphous silicon, polysilicon, and commercial products and prototypes); and projection displays (comparison of Japanese and U.S. display research, and technical evaluation of work).

21 CFR 862.2260 - High pressure liquid chromatography system for clinical use.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false High pressure liquid chromatography system for... Clinical Laboratory Instruments § 862.2260 High pressure liquid chromatography system for clinical use. (a) Identification. A high pressure liquid chromatography system for clinical use is a device intended to separate...

21 CFR 862.2260 - High pressure liquid chromatography system for clinical use.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false High pressure liquid chromatography system for... Clinical Laboratory Instruments § 862.2260 High pressure liquid chromatography system for clinical use. (a) Identification. A high pressure liquid chromatography system for clinical use is a device intended to separate...

21 CFR 862.2260 - High pressure liquid chromatography system for clinical use.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false High pressure liquid chromatography system for... Clinical Laboratory Instruments § 862.2260 High pressure liquid chromatography system for clinical use. (a) Identification. A high pressure liquid chromatography system for clinical use is a device intended to separate...

21 CFR 862.2260 - High pressure liquid chromatography system for clinical use.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false High pressure liquid chromatography system for... Clinical Laboratory Instruments § 862.2260 High pressure liquid chromatography system for clinical use. (a) Identification. A high pressure liquid chromatography system for clinical use is a device intended to separate...

21 CFR 862.2260 - High pressure liquid chromatography system for clinical use.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false High pressure liquid chromatography system for... Clinical Laboratory Instruments § 862.2260 High pressure liquid chromatography system for clinical use. (a) Identification. A high pressure liquid chromatography system for clinical use is a device intended to separate...

Real-space analysis of diffusion behavior and activation energy of individual monatomic ions in a liquid.

PubMed

Miyata, Tomohiro; Uesugi, Fumihiko; Mizoguchi, Teruyasu

2017-12-01

Investigation of the local dynamic behavior of atoms and molecules in liquids is crucial for revealing the origin of macroscopic liquid properties. Therefore, direct imaging of single atoms to understand their motions in liquids is desirable. Ionic liquids have been studied for various applications, in which they are used as electrolytes or solvents. However, atomic-scale diffusion and relaxation processes in ionic liquids have never been observed experimentally. We directly observe the motion of individual monatomic ions in an ionic liquid using scanning transmission electron microscopy (STEM) and reveal that the ions diffuse by a cage-jump mechanism. Moreover, we estimate the diffusion coefficient and activation energy for the diffusive jumps from the STEM images, which connect the atomic-scale dynamics to macroscopic liquid properties. Our method is the only available means to observe the motion, reactions, and energy barriers of atoms/molecules in liquids.

Structure-Antibacterial Activity Relationships of Imidazolium-Type Ionic Liquid Monomers, Poly(ionic liquids) and Poly(ionic liquid) Membranes: Effect of Alkyl Chain Length and Cations.

PubMed

Zheng, Zhiqiang; Xu, Qiming; Guo, Jiangna; Qin, Jing; Mao, Hailei; Wang, Bin; Yan, Feng

2016-05-25

The structure-antibacterial activity relationship between the small molecular compounds and polymers are still elusive. Here, imidazolium-type ionic liquid (IL) monomers and their corresponding poly(ionic liquids) (PILs) and poly(ionic liquid) membranes were synthesized. The effect of chemical structure, including carbon chain length of substitution at the N3 position and charge density of cations (mono- or bis-imidazolium) on the antimicrobial activities against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated by determination of minimum inhibitory concentration (MIC). The antibacterial activities of both ILs and PILs were improved with the increase of the alkyl chain length and higher charge density (bis-cations) of imidazolium cations. Moreover, PILs exhibited lower MIC values relative to the IL monomers. However, the antibacterial activities of PIL membranes showed no correlation to those of their analogous small molecule IL monomers and PILs, which increased with the charge density (bis-cations) while decreasing with the increase of alkyl chain length. The results indicated that antibacterial property studies on small molecules and homopolymers may not provide a solid basis for evaluating that in corresponding polymer membranes.

Effect of ionic liquid on activity, stability, and structure of enzymes: a review.

PubMed

Naushad, Mu; Alothman, Zied Abdullah; Khan, Abbul Bashar; Ali, Maroof

2012-11-01

Ionic liquids have shown their potential as a solvent media for many enzymatic reactions as well as protein preservation, because of their unusual characteristics. It is also observed that change in cation or anion alters the physiochemical properties of the ionic liquids, which in turn influence the enzymatic reactions by altering the structure, activity, enatioselectivity, and stability of the enzymes. Thus, it is utmost need of the researchers to have full understanding of these influences created by ionic liquids before choosing or developing an ionic liquid to serve as solvent media for enzymatic reaction or protein preservation. So, in the present review, we try to shed light on effects of ionic liquids chemistry on structure, stability, and activity of enzymes, which will be helpful for the researchers in various biocatalytic applications. Copyright © 2012. Published by Elsevier B.V.

Rapid resolution liquid chromatography-mass spectrometry and high-performance liquid chromatography-fluorescence detection for metabolism and pharmacokinetic studies of ergosta-4,6,8(14),22-tetraen-3-one.

PubMed

Zhao, Ying-Yong; Qin, Xiang-Yang; Cheng, Xian-Long; Liu, Xue-Ying; Lin, Rui-Chao; Zhang, Yongmin; Li, Xiao-Ye; Sun, Xiao-Li; Sun, Wen-Ji

2010-08-24

Ergosta-4,6,8(14),22-tetraen-3-one (ergone) from many medicinal plants has been demonstrated to possess a variety of pharmacological activities in vivo and in vitro, including cytotoxic, diuretic and immunosuppressive activity. Metabolism and pharmacokinetic studies on rat were conducted for ergone. Rapid resolution liquid chromatography with atmospheric pressure chemical ionization tandem multi-stage mass spectrometry (RRLC-APCI-MS(n)) and high-performance liquid chromatography with fluorescence detection (HPLC-FLD) methods were applied for the identification and quantification of ergone and its metabolite from rat plasma, faeces and urine. A metabolite was identified by RRLC-DAD-APCI-MS(n): 22,23-epoxy-ergosta-4,6,8(14)-triaen-3-one (epoxyergone). The concentrations of the analyte with its metabolites were determined by HPLC-FLD at excitation wavelength of 370 nm and emission wavelength of 485 nm. The samples were deproteinized with methanol after addition of camptothecin as internal standard (IS). The analysis was performed on a Diamonsil C18 column (150 mm x 4.6 mm x 5 microm) with a mobile phase gradient consisting of methanol and water at a flow rate of 1 mL min(-1). The assay was linear over the concentration range of 42-1500, 36-7500 and 42-1500 ng mL(-1) for plasma, faecal homogenate and urine respectively. The absolute recoveries were found to be 97.0+/-1.2%, 98.1+/-0.7% and 96.6+/-1.8% for plasma, faecal homogenate and urine respectively. The intra-day and inter-day relative standard deviations (RSD) were less than 10%. The previous HPLC-MS/MS method is not affordable for most laboratories because of the specialty requirement and high equipment cost. However, the HPLC-FLD method is economic and operating simply for quantitative determination of ergone and its metabolite in rat plasma, faeces and urine. In addition, liquid chromatography coupled with ion trap multi-stage mass spectrometry is becoming a useful technique for ergone metabolite identification. 2010 Elsevier B.V. All rights reserved.

High-pressure liquid chromatography: A brief introduction and its application in analyzing the degradation of a C-ether (Thio-ether) liquid lubricant

NASA Technical Reports Server (NTRS)

1983-01-01

The general principles of classical liquid chromatography and high pressure liquid chromatography (HPLC) are reviewed, and their advantages and disadvantages are compared. Several chromatographic techniques are reviewed, and the analytical separation of a C-ether liquid lubricant by each technique is illustrated. A practical application of HPLC is then demonstrated by analyzing a degraded C-ether liquid lubricant from full scale, high temperature bearing tests.

High-performance supercapacitor electrode materials prepared from various pollens.

PubMed

Zhang, Long; Zhang, Fan; Yang, Xi; Leng, Kai; Huang, Yi; Chen, Yongsheng

2013-04-22

Supercapacitors based on activated carbon prepared from various pollens show good specific capacitance (207 F g(-1) ) and large gravimetric and volumetric energy density (∼88 Wh kg(-1) and ∼44 Wh L(-1) , respectively) in ionic liquid electrolytes, which are much better than those of RP20 (commercial activated carbon) or graphene-based supercapacitors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tuning the morphology and structure of nanocarbons with activating agents for ultrafast ionic liquid-based supercapacitors

NASA Astrophysics Data System (ADS)

Cui, Yongpeng; Wang, Huanlei; Mao, Nan; Yu, Wenhua; Shi, Jing; Huang, Minghua; Liu, Wei; Chen, Shougang; Wang, Xin

2017-09-01

The increasing demand for supercapacitors with high energy and power density has attracted extensive attention in designing advanced carbon materials with high accessible surface area, hierarchical porosity, and 2D/3D morphology. Here, we report a new approach to tune the morphology and structure of the nanocarbons by using methyl cellulose as the precursor. Due to the varying effect of different activating agents, the interconnected sheet-like carbon with a high surface area of up to 2285 m2 g-1 and a thickness down to ∼4 nm can be obtained. These important characteristics make the nanocarbons demonstrate a high capacitance of 144 F g-1 at 1 A g-1 and 20 °C, and an excellent capacitance retention ratio of 64% at 100 A g-1 in ionic liquid. Because of the high fraction of meso/macropores for nanocarbons, an outstanding capacitance of 116 F g-1 can be achieved at 0 °C, with a high capacitance retention ratio of 39% at 100 A g-1. A high energy of 16-17 and 9-10 W h kg-1 can be maintained at 20 and 0 °C when the supercapacitor is charged in less than 1s. The excellent electrochemical response of nanocarbons suggests that the proposed preparation process is promising for developing advanced carbon electrodes.

Vasorelaxant prenylated flavonoids from the roots of Sophora flavescens.

PubMed

Kim, Chul Young; Kim, Hyun Jung; Kim, Kyeong-Man; Oak, Min-Ho

2013-01-01

Bioassay-guided fractionation of the methanol extract from the root of Sophora flavescens led to the isolation of eight known prenylated flavonoids responsible for the vasorelaxation activity in porcine coronary arteries. Among them, kushenol N and 5-methylsophoraflavanone B strongly induced the relaxation of porcine coronary arteries with respective ED(50) values of 8.6 and 12.4 µM. This activity and the results of a high-performance liquid chromatographic analysis suggest that kushenol N and 5-methylsophoraflavanone B could be active markers in the S. flavescens extract for vasorelaxation activity.

Actively convected liquid metal divertor

NASA Astrophysics Data System (ADS)

Shimada, Michiya; Hirooka, Yoshi

2014-12-01

The use of actively convected liquid metals with j × B force is proposed to facilitate heat handling by the divertor, a challenging issue associated with magnetic fusion experiments such as ITER. This issue will be aggravated even more for DEMO and power reactors because the divertor heat load will be significantly higher and yet the use of copper would not be allowed as the heat sink material. Instead, reduced activation ferritic/martensitic steel alloys with heat conductivities substantially lower than that of copper, will be used as the structural materials. The present proposal is to fill the lower part of the vacuum vessel with liquid metals with relatively low melting points and low chemical activities including Ga and Sn. The divertor modules, equipped with electrodes and cooling tubes, are immersed in the liquid metal. The electrode, placed in the middle of the liquid metal, can be biased positively or negatively with respect to the module. The j × B force due to the current between the electrode and the module provides a rotating motion for the liquid metal around the electrodes. The rise in liquid temperature at the separatrix hit point can be maintained at acceptable levels from the operation point of view. As the rotation speed increases, the current in the liquid metal is expected to decrease due to the v × B electromotive force. This rotating motion in the poloidal plane will reduce the divertor heat load significantly. Another important benefit of the convected liquid metal divertor is the fast recovery from unmitigated disruptions. Also, the liquid metal divertor concept eliminates the erosion problem.

Enzymatic properties of the glycine D-alanine [corrected] aminopeptidase of Aspergillus oryzae and its activity profiles in liquid-cultured mycelia and solid-state rice culture (rice koji).

PubMed

Marui, Junichiro; Matsushita-Morita, Mayumi; Tada, Sawaki; Hattori, Ryota; Suzuki, Satoshi; Amano, Hitoshi; Ishida, Hiroki; Yamagata, Youhei; Takeuchi, Michio; Kusumoto, Ken-Ichi

2012-01-01

The gdaA gene encoding S12 family glycine-D-alanine aminopeptidase (GdaA) was found in the industrial fungus Aspergillus oryzae. GdaA shares 43% amino acid sequence identity with the D-aminopeptidase of the Gram-negative bacterium Ochrobactrum anthropi. GdaA purified from an A. oryzae gdaA-overexpressing strain exhibited high D-stereospecificity and efficiently released N-terminal glycine and D-alanine of substrates in a highly specific manner. The optimum pH and temperature were 8 to 9 and 40°C, respectively. This enzyme was stable under alkaline conditions at pH 8 to 11 and relatively resistant to acidic conditions until pH 5.0. The chelating reagent EDTA, serine protease inhibitors such as AEBSF, benzamidine, TPCK, and TLCK, and the thiol enzyme inhibitor PCMB inhibited the enzyme. The aminopeptidase inhibitor bestatin did not affect the activity. GdaA was largely responsible for intracellular glycine and D-alanine aminopeptidase activities in A. oryzae during stationary-phase growth in liquid media. In addition, the activity increased in response to the depletion of nitrogen or carbon sources in the growth media, although the GdaA-independent glycine aminopeptidase activity highly increased simultaneously. Aminopeptidases of A. oryzae attract attention because the enzymatic release of a variety of amino acids and peptides is important for the enhancement of the palatability of fermented foods. GdaA activity was found in extracts of a solid-state rice culture of A. oryzae (rice koji), which is widely used as a starter culture for Japanese traditional fermented foods, and was largely responsible for the glycine and D-alanine aminopeptidase activity detected at a pH range of 6 to 9.

MetILs 3: A Strategy for High Density Energy Storage Using Redox-Active Ionic Liquids

DOE PAGES

Small, Leo J.; Pratt, Harry D.; Staiger, Chad L.; ...

2017-07-26

We present a systematic approach for increasing the concentration of redox-active species in electrolytes for nonaqueous redox flow batteries (RFBs). Starting with an ionic liquid consisting of a metal coordination cation (MetIL), ferrocene-containing ligands and iodide anions are substituted incrementally into the structure. While chemical structures can be drawn for molecules with 10 m redox-active electrons (RAE), practical limitations such as melting point and phase stability constrain the structures to 4.2 m RAE, a 2.3× improvement over the original MetIL. Dubbed “MetILs 3,” these ionic liquids possess redox activity in the cation core, ligands, and anions. Throughout all compositions, infraredmore » spectroscopy shows the ethanolamine-based ligands primarily coordinate to the Fe 2+ core via hydroxyl groups. Calorimetry conveys a profound change in thermophysical properties, not only in melting temperature but also in suppression of a cold crystallization only observed in the original MetIL. Square wave voltammetry reveals redox processes characteristic of each molecular location. Testing a laboratory-scale RFB demonstrates Coulombic efficiencies >95% and increased voltage efficiencies due to more facile redox kinetics, effectively increasing capacity 4×. Application of this strategy to other chemistries, optimizing melting point and conductivity, can yield >10 m RAE, making nonaqueous RFB a viable technology for grid scale storage.« less

Measurement of tritium with high efficiency by using liquid scintillation counter with plastic scintillator.

PubMed

Furuta, Etsuko; Ohyama, Ryu-ichiro; Yokota, Shigeaki; Nakajo, Toshiya; Yamada, Yuka; Kawano, Takao; Uda, Tatsuhiko; Watanabe, Yasuo

2014-11-01

The detection efficiencies of tritium samples by using liquid scintillation counter with hydrophilic plastic scintillator (PS) was approximately 48% when the sample of 20 μL was held between 2 PS sheets treated by plasma. The activity and count rates showed a good relationship between 400 Bq to 410 KBq mL(-1). The calculated detection limit of 2 min measurement by the PS was 13 Bq mL(-1) when a confidence was 95%. The plasma method for PS produces no radioactive waste. Copyright © 2014 Elsevier Ltd. All rights reserved.

Persistence of rotenone in ponds at different temperatures

USGS Publications Warehouse

Gilderhus, P.A.; Allen, J.L.; Dawson, V.K.

1986-01-01

Two ponds were treated with liquid rotenone (5% rotenone), one with 3 mg/L at 24°C and the other with 2 mg/L at 0°C (concentrations of active rotenone were 0.15 and 0.10 mg/L, respectively). Water samples were collected and analyzed by high-performance liquid chromatography. The concentration of rotenone declined to 0.02 mg/L in 48 h in warm water and in 11 d in cold water. The half-life of rotenone was calculated at 13.9 h in warm water and 83.9 h in cold water.

Hydrolysis-acidogenesis of food waste in solid-liquid-separating continuous stirred tank reactor (SLS-CSTR) for volatile organic acid production.

PubMed

Karthikeyan, Obulisamy Parthiba; Selvam, Ammaiyappan; Wong, Jonathan W C

2016-01-01

The use of conventional continuous stirred tank reactor (CSTR) can affect the methane (CH4) recovery in a two-stage anaerobic digestion of food waste (FW) due to carbon short circuiting in the hydrolysis-acidogenesis (Hy-Aci) stage. In this research, we have designed and tested a solid-liquid-separating CSTR (SLS-CSTR) for effective Hy-Aci of FW. The working conditions were pH 6 and 9 (SLS-CSTR-1 and -2, respectively); temperature-37°C; agitation-300rpm; and organic loading rate (OLR)-2gVSL(-1)day(-1). The volatile fatty acids (VFA), enzyme activities and bacterial population (by qPCR) were determined as test parameters. Results showed that the Hy-Aci of FW at pH 9 produced ∼35% excess VFA as compared to that at pH 6, with acetic and butyric acids as major precursors, which correlated with the high enzyme activities and low lactic acid bacteria. The design provided efficient solid-liquid separation there by improved the organic acid yields from FW. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cooperative Activated Transport of Dilute Penetrants in Viscous Molecular and Polymer Liquids

NASA Astrophysics Data System (ADS)

Schweizer, Kenneth; Zhang, Rui

We generalize the force-level Elastically Collective Nonlinear Langevin Equation theory of activated relaxation in one-component supercooled liquids to treat the hopping transport of a dilute penetrant in a dense hard sphere fluid. The new idea is to explicitly account for the coupling between penetrant displacement and a local matrix cage re-arrangement which facilitates its hopping. A temporal casuality condition is employed to self-consistently determine a dimensionless degree of matrix distortion relative to the penetrant jump distance using the dynamic free energy concept. Penetrant diffusion becomes increasingly coupled to the correlated matrix displacements for larger penetrant to matrix particle size ratio (R) and/or attraction strength (physical bonds), but depends weakly on matrix packing fraction. In the absence of attractions, a nearly exponential dependence of penetrant diffusivity on R is predicted in the intermediate range of 0.2

Removal of bisphenol A in canned liquid food by enzyme-based nanocomposites

NASA Astrophysics Data System (ADS)

Tapia-Orozco, Natalia; Meléndez-Saavedra, Fanny; Figueroa, Mario; Gimeno, Miquel; García-Arrazola, Roeb

2018-02-01

Laccase from Trametes versicolor was immobilized on TiO2 nanoparticles; the nanocomposites obtained were used for the removal of bisphenol A (BPA) in a liquid food matrix. To achieve a high enzymatic stability over a wide pH range and at temperatures above 50 °C, the nanocomposite structures were prepared by both physical adsorption and covalent linking of the enzyme onto the nanometric support. All the nanocomposite structures retained 40% of their enzymatic activity after 60 days of storage. Proof-of-concept experiments in aqueous media using the nanocomposites resulted on a > 60% BPA removal after 48 h and showed that BPA was depleted within 5 days. The nanocomposites were tested in canned liquid food samples; the removal reached 93.3% within 24 h using the physically adsorbed laccase. For the covalently linked enzyme, maximum BPA removal was 91.3%. The formation of BPA dimers and trimers was observed in all the assays. Food samples with sugar and protein contents above 3 and 4 mg mL-1 showed an inhibitory effect on the enzymatic activity.

Effect of high surface area activated carbon on thermal degradation of jet fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gergova, K.; Eser, S.; Arumugam, R.

1995-05-01

Different solid carbons added to jet fuel during thermal stressing cause substantial changes in pyrolytic degradation reactions. Activated carbons, especially high surface area activated carbons were found to be very effective in suppressing solid deposition on metal reactor walls during stressing at high temperatures (425 and 450{degrees}C). The high surface area activated carbon PX-21 prevented solid deposition on reactor walls even after 5h at 450{degrees}C. The differences seen in the liquid product composition when activated carbon is added indicated that the carbon surfaces affect the degradation reactions. Thermal stressing experiments were carried out on commercial petroleum-derived JPTS jet fuel. Wemore » also used n-octane and n-dodecane as model compounds in order to simplify the study of the chemical changes which take place upon activated carbon addition. In separate experiments, the presence of a hydrogen donor, decalin, together with PX-21 was also studied.« less

Phase change events of volatile liquid perfluorocarbon contrast agents produce unique acoustic signatures

PubMed Central

Sheeran, Paul S.; Matsunaga, Terry O.; Dayton, Paul A.

2015-01-01

Phase-change contrast agents (PCCAs) provide a dynamic platform to approach problems in medical ultrasound (US). Upon US-mediated activation, the liquid core vaporizes and expands to produce a gas bubble ideal for US imaging and therapy. In this study, we demonstrate through high-speed video microscopy and US interrogation that PCCAs composed of highly volatile perfluorocarbons (PFCs) exhibit unique acoustic behavior that can be detected and differentiated from standard microbubble contrast agents. Experimental results show that when activated with short pulses PCCAs will over-expand and undergo unforced radial oscillation while settling to a final bubble diameter. The size-dependent oscillation phenomenon generates a unique acoustic signal that can be passively detected in both time and frequency domain using confocal piston transducers with an ‘activate high’ (8 MHz, 2 cycles), ‘listen low’ (1 MHz) scheme. Results show that the magnitude of the acoustic ‘signature’ increases as PFC boiling point decreases. By using a band-limited spectral processing technique, the droplet signals can be isolated from controls and used to build experimental relationships between concentration and vaporization pressure. The techniques shown here may be useful for physical studies as well as development of droplet-specific imaging techniques. PMID:24351961

Fingerprint profiles of flavonoid compounds from different Psidium guajava leaves and their antioxidant activities.

PubMed

Wang, Lu; Wu, Yanan; Bei, Qi; Shi, Kan; Wu, Zhenqiang

2017-10-01

Flavonoids are the main active components in Psidium guajava leaves and have many multi-physiological functions. In this study, the flavonoid compositions were identified in the Psidium guajava leaves samples using a high-performance liquid chromatography with time-of-flight electrospray ionization mass spectrometry method. A high-performance liquid chromatography fingerprint method, combined with chemometrics, was used to perform a quality assessment of the Psidium guajava leaves samples. The eight identified flavonoid compounds including rutin, isoquercitrin, quercetin-3-O-β-d-xylopyranoside, quercetin-3-O-α-l-arabinopyranoside, avicularin, quercitrin, quercetin, and kaempferol were used as the chemical markers. The antioxidant activity of 15 batches of samples was examined using three different methods, and the results revealed the Psidium guajava leaves samples that had higher contents of the flavonoid compounds, glycoside and aglycone, possessed the highest antioxidant capacities. Consequently, a combination of chromatographic fingerprints and chemometric analyses was used for a quality assessment of Psidium guajava leaf tea and its derived products, which can lay the foundation for the development of plant tea resources or other herbs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cytotoxic and Immunomodulatory Potential Activity of Physalis peruviana Fruit Extracts on Cervical Cancer (HeLa) and Fibroblast (L929) Cells.

PubMed

Mier-Giraldo, Helen; Díaz-Barrera, Luis Eduardo; Delgado-Murcia, Lucy Gabriela; Valero-Valdivieso, Manuel Fernando; Cáez-Ramírez, Gabriela

2017-10-01

It was purposed to evaluate the biological potential of ethanol and isopropanol crude extracts of ripe Physalis peruviana fruits. Cytotoxic and immunomodulatory effects of the expression of interleukin-6, interleukin-8, and monocyte chemoattractant protein-1 (MCP-1) were evaluated on human cervical cancer (HeLa) and murine fibroblast (L929) cells. The composition was evaluated by high-performance liquid chromatography diode-array detection and high-performance liquid chromatography ultraviolet/visible detection. The presence of ursolic acid and rosmarinic acid was found in both solvents. However, gallic acid, quercetin, and epicatechin were higher in isopropanol extracts ( P < .05). The results indicated a relationship among the total polyphenol content, antioxidant activity, and cytotoxic activity that was dependent on the solvent used. Isopropanol extracts presented a half-maximal inhibition concentration value (IC 50 ) of 60.48 ± 3.8 μg/mL for HeLa cells and 66.62 ± 2.67 μg/mL for L929 fibroblasts. The extracts reduced the release of interleukin-6, interleukin-8, and MCP-1 in a dose-dependent manner. Extracts showed anticancer and immunomodulatory potential for new complementary pharmaceutical products development.

Cytotoxic and Immunomodulatory Potential Activity of Physalis peruviana Fruit Extracts on Cervical Cancer (HeLa) and Fibroblast (L929) Cells

PubMed Central

Mier-Giraldo, Helen; Díaz-Barrera, Luis Eduardo; Delgado-Murcia, Lucy Gabriela; Valero-Valdivieso, Manuel Fernando; Cáez-Ramírez, Gabriela

2017-01-01

It was purposed to evaluate the biological potential of ethanol and isopropanol crude extracts of ripe Physalis peruviana fruits. Cytotoxic and immunomodulatory effects of the expression of interleukin-6, interleukin-8, and monocyte chemoattractant protein-1 (MCP-1) were evaluated on human cervical cancer (HeLa) and murine fibroblast (L929) cells. The composition was evaluated by high-performance liquid chromatography diode-array detection and high-performance liquid chromatography ultraviolet/visible detection. The presence of ursolic acid and rosmarinic acid was found in both solvents. However, gallic acid, quercetin, and epicatechin were higher in isopropanol extracts (P < .05). The results indicated a relationship among the total polyphenol content, antioxidant activity, and cytotoxic activity that was dependent on the solvent used. Isopropanol extracts presented a half-maximal inhibition concentration value (IC50) of 60.48 ± 3.8 μg/mL for HeLa cells and 66.62 ± 2.67 μg/mL for L929 fibroblasts. The extracts reduced the release of interleukin-6, interleukin-8, and MCP-1 in a dose-dependent manner. Extracts showed anticancer and immunomodulatory potential for new complementary pharmaceutical products development. PMID:28719984

Method of making electrodes for electrochemical cell

DOEpatents

Kaun, Thomas D.; Kilsdonk, Dennis J.

1983-01-01

A method of making an electrode for an electrochemical cell in which particulate electrode-active material is mixed with a liquid organic carrier chemically inert with respect to the electrode-active material, mixing the liquid carrier to form an extrudable slurry. The liquid carrier is present in an amount of from about 10 to about 50 percent by volume of the slurry, and then the carrier is removed from the slurry leaving the electrode-active material.

Liquid-Crystal-Enabled Active Plasmonics: A Review

PubMed Central

Si, Guangyuan; Zhao, Yanhui; Leong, Eunice Sok Ping; Liu, Yan Jun

2014-01-01

Liquid crystals are a promising candidate for development of active plasmonics due to their large birefringence, low driving threshold, and versatile driving methods. We review recent progress on the interdisciplinary research field of liquid crystal based plasmonics. The research scope of this field is to build the next generation of reconfigurable plasmonic devices by combining liquid crystals with plasmonic nanostructures. Various active plasmonic devices, such as switches, modulators, color filters, absorbers, have been demonstrated. This review is structured to cover active plasmonic devices from two aspects: functionalities and driven methods. We hope this review would provide basic knowledge for a new researcher to get familiar with the field, and serve as a reference for experienced researchers to keep up the current research trends. PMID:28788515

Optical and structural properties of carbon dots/TiO2 nanostructures prepared via DC arc discharge in liquid

NASA Astrophysics Data System (ADS)

Biazar, Nooshin; Poursalehi, Reza; Delavari, Hamid

2018-01-01

Synthesis and development of visible active catalysts is an important issue in photocatalytic applications of nanomaterials. TiO2 nanostructures coupled with carbon dots demonstrate a considerable photocatalytic activity in visible wavelengths. Extending optical absorption of a wide band gap semiconductor such as TiO2 with carbon dots is the origin of the visible activity of carbon dots modified semiconductor nanostructures. In addition, carbon dots exhibit high photostability, appropriate electron transport and chemical stability without considerable toxicity or environmental footprints. In this study, optical and structural properties of carbon dots/TiO2 nanostructures prepared via (direct current) DC arc discharge in liquid were investigated. Crystal structure, morphology and optical properties of the samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy respectively. SEM images show formation of spherical nanoparticles with an average size of 27 nm. In comparison with pristine TiO2, optical transmission spectrum of carbon dots/TiO2 nanostructures demonstrates an absorption edge at longer wavelengths as well a high optical absorption in visible wavelengths which is significant for visible activity of nanostructures as a photocatalyst. Finally, these results can provide a flexible and versatile pathway for synthesis of carbon dots/oxide semiconductor nanostructures with an appropriate activity under visible light.

Highly Effective Pt-Based Water-Gas Shift Catalysts by Surface Modification with Alkali Hydroxide Salts

DOE PAGES

Kusche, Matthias; Bustillo, Karen; Agel, Friederike; ...

2015-01-29

Here, we describe an economical and convenient method to improve the performance of Pt/alumina catalysts for the water–gas shift reaction through surface modification of the catalysts with alkali hydroxides according to the solid catalyst with ionic liquid layer approach. The results are in agreement with our findings reported earlier for methanol steam reforming. This report indicates that alkali doping of the catalyst plays an important role in the observed catalyst activation. In addition, the basic and hygroscopic nature of the salt coating contributes to a significant improvement in the performance of the catalyst. During the reaction, a partly liquid filmmore » of alkali hydroxide forms on the alumina surface, which increases the availability of H 2O at the catalytically active sites. Kinetic studies reveal a negligible effect of the KOH coating on the rate dependence of CO and H 2O partial pressures. In conclusion, TEM studies indicate an agglomeration of the active Pt clusters during catalyst preparation; restructuring of Pt nanoparticles occurs under reaction conditions, which leads to a highly active and stable system over 240h time on stream. Excessive pore fillings with KOH introduce a mass transfer barrier as indicated in a volcano-shaped curve of activity versus salt loading. The optimum KOH loading was found to be 7.5wt%.« less

Vibration-free stirling cryocooler for high definition microscopy

NASA Astrophysics Data System (ADS)

Riabzev, S. V.; Veprik, A. M.; Vilenchik, H. S.; Pundak, N.; Castiel, E.

2009-12-01

The normal operation of high definition Scanning Electronic and Helium Ion microscope tools often relies on maintaining particular components at cryogenic temperatures. This has traditionally been accomplished by using liquid coolants such as liquid Nitrogen. This inherently limits the useful temperature range to above 77 K, produces various operational hazards and typically involves elevated ownership costs, inconvenient logistics and maintenance. Mechanical coolers, over-performing the above traditional method and capable of delivering required (even below 77 K) cooling to the above cooled components, have been well-known elsewhere for many years, but their typical drawbacks, such as high purchasing cost, cooler size, low reliability and high power consumption have so far prevented their wide-spreading. Additional critical drawback is inevitable degradation of imagery performance originated from the wideband vibration export as typical for the operation of the mechanical cooler incorporating numerous movable components. Recent advances in the development of reliable, compact, reasonably priced and dynamically quiet linear cryogenic coolers gave rise to so-called "dry cooling" technologies aimed at eventually replacing the traditional use of outdated liquid Nitrogen cooling facilities. Although much improved these newer cryogenic coolers still produce relatively high vibration export which makes them incompatible with modern high definition microscopy tools. This has motivated further research activity towards developing a vibration free closed-cycle mechanical cryocooler. The authors have successfully adapted the standard low vibration Stirling cryogenic refrigerator (Ricor model K535-LV) delivering 5 W@40 K heat lift for use in vibration-sensitive high definition microscopy. This has been achieved by using passive mechanical counterbalancing of the main portion of the low frequency vibration export in combination with an active feed-forward multi-axes suppression of the residual wideband vibration, thermo-conductive vibration isolation struts and soft vibration mounts. The attainable performance of the resulting vibration free linear Stirling cryocooler (Ricor model K535-ULV) is evaluated through a full-scale experimentation.

Preparation of Sesquiterpenoids from Tussilago farfara L. by High-speed Counter-current Chromatography

PubMed Central

Cao, Kun; Xu, Yi; Zhao, Tian-Ming; Zhang, Qing

2016-01-01

Background: Sesquiterpenoids, such as tussilagone, has effects of raising blood pressure, antiplatelet aggregation, and anti-inflammation activities, which is regarded as index compound for quality control of Tussilago farfara L. Objective: This study was aimed to obtain an effective method for fast isolation of sesquiterpenoids from T. farfara L. by high-speed counter-current chromatography (HSCCC). Materials and Methods: A solvent optimization method for HSCCC was presented, i.e., the separation factors of compounds after the K values of solvent system should be investigated. Results: A ternary solvent system of n-hexane:methanol:water (5:8:2, v/v/v) was selected and applied for the HSCCC, and 56 mg of tussilagone (2) was isolated from T. farfara L., along with two other sesquiterpenoids 5.6 mg of 2,2-dimethyl-6-acetylchromanone (1) and 22 mg of 14-acetoxy-7 β-(3’-ethyl cis-crotonoyloxy)-lα-(2’-methylbutyryloxy)-notonipetranone (3) by HSCCC with high purities. Their chemical structures were elucidated by liquid chromatography-mass spectrometry and nuclear magnetic resonance experiments. Conclusion: These results offered an efficient strategy for preparation of potentially health-relevant phytochemicals from T. farfara L., which might be used for further chemical research and pharmacological studies by preparative HSCCC. SUMMARY The real separation efficiency has been verified by analytical HSCCC.A solvent optimization method for HSCCC was presented and applied to separate and prepare active compounds.A method for rapid and effective separation of target compound Tussilagone with high yield and purity from the flower buds of Tussilago farfara.Two other compounds 2,2-Dimethyl-6-acetylchromanone and 14-acetoxy-7β-(3’-ethyl cis-crotonoyloxy) -lα- (2’-methylbutyryloxy). notonipetranone hasbeen obtained with high purities from flower buds of Tussilago farfara. Abbreviations used: HSCCC: High-Speed Counter-Current Chromatography; LC-MS: Liquid Chromatograph-Mass Spectrometer; NMR: Nuclear Magnetic Resonance; TCM: Traditional Chinese Medicine; HPLC: High Performance Liquid Chromatography; ESI-MS: Electrospray Ionization Mass Spectrometry; PE: petroleum ether PMID:27867270

Determination of chlorophenols in honey samples using in-situ ionic liquid-dispersive liquid-liquid microextraction as a pretreatment method followed by high-performance liquid chromatography.

PubMed

Fan, Chen; Li, Nai; Cao, Xueli

2015-05-01

In-situ ionic liquid-dispersive liquid-liquid microextraction (IL-DLLME) method was developed as a pretreatment method for the detection of six chlorophenols (CPs) in honey samples. The hydrophobic ionic liquid [C4MIM][NTf2], formed in-situ by the hydrophilic ionic liquid [C4MIM][BF4] and the ion exchange reagent LiNTf2 was used as the microextractant solvent of CPs from honey sample. Then the enriched analytes were back-extracted into 40 μL of 0.14 M NaOH solution and finally subjected to analysis by high-performance liquid chromatography. The method showed low limit of detection of CPs, 0.8-3.2 μg/L and high enrichment factor, 34-65 with the recoveries range from 91.60% to 114.33%. The method is simple, rapid, environmentally friendly and with high extraction efficiency. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Role of adsorption in liquid lubrication

NASA Technical Reports Server (NTRS)

Groszek, A. J.

1973-01-01

Changes at solid-liquid interfaces caused by adsorption from solution are discussed paying attention to the following aspects: (1) stability of adsorbed films and the structure of metal-additive-film-liquid interface and effect of adsorbate orientation. (2) chemical versus physical adsorption, (3) heat of adsorption, (4) adsorption of additives, (5) activated adsorption, effect of activating adsorbates, (6) displacement phenomena at solid-liquid interfaces, (7) competition of antiwear additives, their solvents, and water, (8) effect of adsorption on the orientation of liquid in the interfacial region, and (9) relation between the chemical nature of solid surfaces and their interaction with liquid lubricants. The relevance of the above adsorption phenomena to lubrication is discussed, referring where possible to specific examples.

Global deletion of glutathione S-Transferase A4 exacerbates developmental nonalcoholic steatohepatitis

USDA-ARS?s Scientific Manuscript database

We established a mouse model of developmental nonalcoholic steatohepatitis (NASH) by feeding a high polyunsaturated fat liquid diet to female glutathione-S-transferase 4-4 (Gsta4-/-)/peroxisome proliferator activated receptor a (Ppara-/-) double knockout 129/SvJ mice for 12 weeks from weaning. We us...

Probing Hydrogen Diffusion under High Pressure

NASA Astrophysics Data System (ADS)

Bove, L. E.; Klotz, S.; Strassle, T.; Saitta, M.

2012-12-01

The study of the microscopic mechanism governing hydrogen and hydrogen-based liquids (as water, ammonia and methane) diffusion is crucial for a variety of scientific issues spanning most of natural sciences. As an example, characterizing hydrogen diffusion in a confined medium, like in porous systems or zeolites, is fundamental in problems relating to environment, hydrogen storage and industrial applications [1]. The presence of water diffusion in the minerals of the Earth's mantle have strong incidence on the processes governing volcanic eruptions and intermediate-depth seismicity. As last example, knowing in details the microscopic dynamics of hydrogen-based simple liquids under extreme conditions is essential in order to interpret observations and develop models of planet interiors [2]. On the other hand, water and other simple hydrogen-based liquids have always been key systems in the development of modern condensed-matter physics, because of their simple electronic structure and the peculiar properties deriving from the hydrogen-bond network. Their high compressibility and chemical reactivity have made these systems very challenging to study experimentally under static high P-T conditions. In the last few years, a large effort has been undertaken by several groups around the world [2] to extend the static and dynamic techniques to high temperatures and pressures, a program in which our group has been actively involved [3-6]. However, while the structure of water and other hydrogenated liquids of geological interest, is now known up to almost 20 GPa, the study of their transport properties greatly lags behind. We have recently developed a new large-volume gasket-anvil ensemble for the Paris-Edinburgh press based on a novel toroidal design [7], which allows to perform quasi elastic neutron scattering measurements on hydrogen based liquids up to one order of magnitude higher pressures (5 GPa) respect to what was achievable with standard methods [8]. The large volume HP press can be now warmed up to 600K and the peculiar geometry of the gasket assure an excellent signal to background ratio. This new device has been recently settled up on neutron scattering facilities (PSI, ILL), successfully showing that very high quality data can be obtained on liquid water, and more generally on hydrogenated liquids dynamics under high pressure. Some new exciting results on the diffusion mechanism in hot dense water will be presented [9]. Possible future implementation of the device to reach the 20GPa and 1000K conditions will be also discussed. References [1] C. Cavazzoni et al., Science 283, 44 (1999) ; T. Guillot, Science 286 (1999), 72 . 77. [2] Some of the most active groups in this field are the Geophysical Laboratory (USA), Lawrence Livermore National Laboratory (USA), CEA/DAM (France) and the Bayerisches Geoinstitut (Allemagne). [3] Klotz S et al, Phys. Rev. Lett. 96 149602, 2006. [4] Nelmes R J Nature Phys. 2 414, 2006. [5] S. Klotz, L. Bove et al., Nature Mat. 8, 405 (2009). [6] L.E. Bove et al., Phys. Rev. Lett., 106 (2011) . [7] L. E. Bove et al., Phys. Appl. Lett., in preparation (2012). [8] A. Cunsolo et al., Journal of Chem. Phys. 124, 084503 (2006). [9] L.E. Bove et al., Phys. Rev. Lett., submitted (2012) .

Synthesis of Highly Dispersed and Highly Stable Supported Au–Pt Bimetallic Catalysts by a Two-Step Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xiaofeng; Zhao, Haiyan; Wu, Tianpin

2016-11-01

Highly dispersed and highly stable supported bimetallic catalysts were prepared using a two-step process. Pt nanoparticles (NPs) were first deposited on porous γ-Al2O3 particles by atomic layer deposition (ALD). Au NPs were synthesized by using gold(III) chloride as the Au precursor, and then immobilized on ALD Pt/γ-Al2O3 particles. The Au–Pt bimetallic catalysts were highly active and highly stable in a vigorously stirred liquid phase reaction of glucose oxidation.

Tests and evaluation of a variable focus liquid lens for curvature wavefront sensors in astronomy.

PubMed

Fuentes-Fernández, Jorge; Cuevas, Salvador; Álvarez-Nuñez, Luis C; Watson, Alan

2013-10-20

Curvature wavefront sensors (WFSs), which obtain the wavefront aberrations from two defocused intensity images at each side of the pupil plane, have shown to be highly efficient for astronomical applications. We propose here an alternative defocusing mechanism for curvature sensors, based on an electrowetting-based variable focus liquid lens. Typically, the sampling rates of a WFS for active optics are of the order of 0.01 Hz, and the focus modulation can be done by simply moving the detector back and forth. On the other hand, adaptive optics may require speeds of up to several hundred hertz, and the modulation is then done by using a fast vibrating membrane mirror. We believe variable focus liquid lenses may be able to perform this focus modulation, reducing the overall size of the system and without the need of extra moving parts. We have done a full characterization of the Varioptic Arctic 416 liquid lens, and we have evaluated its potential performance in different curvature configurations.

ZnO nanoneedle/H2O solid-liquid heterojunction-based self-powered ultraviolet detector

PubMed Central

2013-01-01

ZnO nanoneedle arrays were grown vertically on a fluorine-doped tin oxide-coated glass by hydrothermal method at a relatively low temperature. A self-powered photoelectrochemical cell-type UV detector was fabricated using the ZnO nanoneedles as the active photoanode and H2O as the electrolyte. This solid-liquid heterojunction offers an enlarged ZnO/water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. High photosensitivity, excellent spectral selectivity, and fast photoresponse at zero bias are observed in this UV detector. The self-powered behavior can be well explained by the formation of a space charge layer near the interface of the solid-liquid heterojunction, which results in a built-in potential and makes the solid-liquid heterojunction work in photovoltaic mode. PMID:24103153

A strategy for screening of α-glucosidase inhibitors from Morus alba root bark based on the ligand fishing combined with high-performance liquid chromatography mass spectrometer and molecular docking.

PubMed

Wang, Zhen; Li, Xiaoqing; Chen, Menghan; Liu, Feiyan; Han, Chao; Kong, Lingyi; Luo, Jianguang

2018-04-01

A new method based on ligand fishing combined with high-performance liquid chromatography quadrupole-time-of-flight mass spectrometer and molecular docking was established to screen α-glucosidase inhibitors from a traditional Chinese medicine Morus alba root bark. α-Glucosidase was immobilized on magnetic nanoparticles, used as a solid support to incubate with crude extract. After ligand fishing, the eluates were analyzed by high-performance liquid chromatography quadrupole-time-of-flight mass spectrometer, obtaining eleven ligands (1-4, 6-12) eventually. In order to discriminate the non-specific binders and discover powerful enzyme inhibitors, molecular docking was further performed and three of the eleven ligands were optimized to be excellent α-glucosidase inhibitors by the confirmation of isolation and bioassay of individual compounds. These three ligands, sanggenons G (6), O (7) and sanggenol G (12) exhibited striking inhibitory activities with extremely low IC 50 values. The results suggest that established method will be applied to a wide range of target protein to screen potential bioactive constituents from herbal medicines. Copyright © 2017 Elsevier B.V. All rights reserved.

Catalytic decomposition of nitrous oxide monopropellant for hybrid motor ignition

NASA Astrophysics Data System (ADS)

Wilson, Matthew

Nitrous oxide (N2O) is an inexpensive and readily available non-toxic rocket motor oxidizer. It is the most commonly used oxidizer for hybrid bipropellant rocket systems, and several bipropellant liquid rocket designs have also used nitrous oxide. In liquid form, N2O is highly stable, but in vapor form it has the potential to decompose exothermically, releasing up to 1865 Joules per gram of vapor as it dissociates into nitrogen and oxygen. Consequently, it has long been considered as a potential "green" replacement for existing highly toxic and dangerous monopropellants. This project investigates the feasibility of using the nitrous oxide decomposition reaction as a monopropellant energy source for igniting liquid bipropellant and hybrid rockets that already use nitrous oxide as the primary oxidizer. Because nitrous oxide is such a stable propellant, the energy barrier to dissociation is quite high; normal thermal decomposition of the vapor phase does not occur until temperatures are above 800 C. The use of a ruthenium catalyst decreases the activation energy for this reaction to allow rapid decomposition below 400 C. This research investigates the design for a prototype device that channels the energy of dissociation to ignite a laboratory scale hybrid rocket motor.

Optimization of Ultrasonic-Microwave Synergistic Extraction of Ricinine from Castor Cake by Response Surface Methodology.

PubMed

Xu, Wei; Yan, Xiuhua; Shao, Rong; Chen, Ligen; Ke, Zengguang

Castor cake is the residue in castor oil production in which many active components exist and the major one among them is ricinine. In this study, optimization of extraction of ricinine from castor cake using ultrasonic-microwave synergistic extraction (UMSE) was investigated to obtain high yield and purity by Box-Behnken design (BBD) response surface design. The optimal conditions of extraction were: ultrasound power 342 W, extracting time 5 min, microwave power 395 W, and non-significant factor of liquid/solid ratio 1:10. The crude extraction was recrystallized from ethanol. As a result, the maximum yield of ricinine was approximately 67.52%. The purity of ricinine was 99.39% which was determined by high performance liquid chromatography (HPLC). Additionally, the structure of purified ricinine was identified by fourier transforms infrared (FTIR) and liquid chromatography-mass spectrometry (LC-MS). Scanning electron microscope (SEM) was used to characterize the prismatic crystals morphology of ricinine. Results demonstrated that the present method combined the advantages of ultrasonic extraction and microwave extraction, which is time-saving with high extraction yield. Our results offer a suitable method for large-scale isolation of ricinine.

High speed cryogenic self-acting, shaft seals for liquid rocket turbopumps

NASA Technical Reports Server (NTRS)

Burcham, R. E.

1983-01-01

Three self acting lift pad liquid oxygen face seals and two self acting gaseous helium circumferential seals for high speed liquid oxygen turbopump were evaluated. The development of a technology for reliable, 10 hour life, multiple start seals for use in high speed liquid oxygen turbopumps is discussed.

[The extracellular proteases of the phytopathogenic bacterium Xanthomonas campestris].

PubMed

Kalashnikova, E E; Chernyshova, M P; Ignatov, V V

2003-01-01

The culture liquids of three Xanthomonas campestris pv. campestris strains were found to possess proteolytic activity. The culture liquid of strain B-611 with the highest proteolytic activity was fractionated by salting-out with ammonium sulfate, gel filtration, and ion-exchange chromatography. The electrophoretic analysis of active fractions showed the presence of two proteases in the culture liquid of strain B-611, the major of which being serine protease. The treatment of cabbage seedlings with the proteases augmented the activity of peroxidase in the cabbage roots by 28%.

Design and performance of a trickling air biofilter for chlorobenzene and o-dichlorobenzene vapors.

PubMed Central

Oh, Y S; Bartha, R

1994-01-01

From contaminated industrial sludge, two stable multistrain microbial enrichments (consortia) that were capable of rapidly utilizing chlorobenzene and o-dichlorobenzene, respectively, were obtained. These consortia were characterized as to their species composition, tolerance range, and activity maxima in order to establish and maintain the required operational parameters during their use in biofilters for the removal of chlorobenzene contaminants from air. The consortia were immobilized on a porous perlite support packed into filter columns. Metered airstreams containing the contaminant vapors were partially humidified and passed through these columns. The vapor concentrations prior to and after biofiltration were measured by gas chromatography. Liquid was circulated concurrently with the air, and the device was operated in the trickling air biofilter mode. The experimental arrangement allowed the independent variation of liquid flow, airflow, and solvent vapor concentrations. Bench-scale trickling air biofilters removed monochlorobenzene, o-dichlorobenzene, and their mixtures at rates of up to 300 g of solvent vapor h(-1) m(-3) filter volume. High liquid recirculation rates and automated pH control were critical for stable filtration performance. When the accumulating NaCl was periodically diluted, the trickling air biofilters continued to remove chlorobenzenes for several months with no loss of activity. The demonstrated high performance and stability of the described trickling air biofilters favor their use in industrial-scale air pollution control. PMID:8085815

Enzymes immobilized on amine-terminated ionic liquid-functionalized carbon nanotube for hydrogen peroxide determination.

PubMed

Liu, Xiuhui; Bu, Caihong; Nan, Zhihan; Zheng, Lichun; Qiu, Yu; Lu, Xiaoquan

2013-02-15

We report on a new approach for the electrochemical detection of hydrogen peroxide (H2O2) based on Cytochrome C (Cyt c) immobilized ionic liquid (IL)-functionalized multi-walled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE). Functionalization of multi-walled carbon nanotube with amine-terminated ionic liquid materials was characterized using fourier transform infrared spectroscopy (FTIR), UV-vis spectra, and electrochemical impedance spectroscopy (EIS), and the results showed that the covalent modification of MWCNTs with ILs exhibited a high surface area for enzyme immobilization and provided a good microenvironment for Cyt c to retain its bioelectrocatalytic activity toward H2O2. Amperometry was used to evaluate the catalytic activity of the cyt c towards H2O2. The proposed biosensor exhibited a wide linear response range nearly 4 orders of magnitude of H2O2 (4.0 × 10(-8)M-1.0 × 10(-4)M) with a good linearity (0.9980) and a low detection limit of 1.3 × 10(-8)M (based on S/N=3). Furthermore, the biosensor also displays some other excellent characteristics such as high selectivity, good reproducibility and long-term stability. Thus, the biosensor constructed in this study has great potential for detecting H2O2 in the complex biosystems. Copyright © 2012 Elsevier B.V. All rights reserved.

Superhydrophobic Blood-Repellent Surfaces.

PubMed

Jokinen, Ville; Kankuri, Esko; Hoshian, Sasha; Franssila, Sami; Ras, Robin H A

2018-06-01

Superhydrophobic surfaces repel water and, in some cases, other liquids as well. The repellency is caused by topographical features at the nano-/microscale and low surface energy. Blood is a challenging liquid to repel due to its high propensity for activation of intrinsic hemostatic mechanisms, induction of coagulation, and platelet activation upon contact with foreign surfaces. Imbalanced activation of coagulation drives thrombogenesis or formation of blood clots that can occlude the blood flow either on-site or further downstream as emboli, exposing tissues to ischemia and infarction. Blood-repellent superhydrophobic surfaces aim toward reducing the thrombogenicity of surfaces of blood-contacting devices and implants. Several mechanisms that lead to blood repellency are proposed, focusing mainly on platelet antiadhesion. Structured surfaces can: (i) reduce the effective area exposed to platelets, (ii) reduce the adhesion area available to individual platelets, (iii) cause hydrodynamic effects that reduce platelet adhesion, and (iv) reduce or alter protein adsorption in a way that is not conducive to thrombus formation. These mechanisms benefit from the superhydrophobic Cassie state, in which a thin layer of air is trapped between the solid surface and the liquid. The connections between water- and blood repellency are discussed and several recent examples of blood-repellent superhydrophobic surfaces are highlighted. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrically activated artificial muscles made with liquid crystal elastomers

NASA Astrophysics Data System (ADS)

Shahinpoor, Mohsen

2000-06-01

Composites of monodomain nematic liquid crystal elastomers and a conducting material distributed within their network are shown to exhibit large deformations, i.e. contraction, expansion, bending with strains of over 200% and appreciable force, by Joule heating through electrical activation. The electrical activation of the conducting material induces a rapid Joule heating in the sample leading to a nematic to isotropic phase transition where the elastomer of dimensions 32 mm x 7 mm x 0.4 mm contracted in less than a second. The cooling process, isotropic to nematic transition where the elastomer expands back to its original length, was slow and took 8 seconds. The material studied here is a highly novel liquid crystalline co-elastomer, invented and developed by Heino Finkelmann and co-workers at Albert-Ludwigs-Universitaet in Freiburg, Germany. The material is such that in which the mesogenic units are in both the side chains and the main chains of the elastomer. This co-elastomer was then mechanically loaded to induce a uniaxial network anisotropy before the cross-linking reaction was completed. These samples were then made into a composite with a conducting material such as dispersed silver particles or graphite fibers. The final samples was capable of undergoing more than 200% reversible strain in a few seconds.

In vitro anti-proliferative activity on colon cancer cell line (HT-29) of Thai medicinal plants selected from Thai/Lanna medicinal plant recipe database "MANOSROI III".

PubMed

Manosroi, Aranya; Akazawa, Hiroyuki; Akihisa, Toshihiro; Jantrawut, Pensak; Kitdamrongtham, Worapong; Manosroi, Worapaka; Manosroi, Jiradej

2015-02-23

Thai/Lanna region has its own folklore wisdoms including the traditional medicinal plant recipes. Thai/Lanna medicinal plant recipe database "MANOSROI III" has been developed by Prof. Dr. Jiradej Manosroi. It consists of over 200,000 recipes for all diseases including cancer. To investigate the anti-proliferative and apoptotic activities on human colon cancer cell line (HT-29) as well as the cancer cell selectivity of the methanolic extracts (MEs) and fractions of the 23 selected plants from the "MANOSROI III" database. The 23 selected plants were extracted with methanol under reflux and evaluated for their anti-proliferative activity by sulforhodamine B assay. The 5 plants (Gloriosa superba, Caesalpinia sappan, Fibraurea tinctoria, Ventilago denticulata and Psophocarpus tetragonolobus) with potent anti-proliferative activity were fractionated by liquid-liquid partition to give 4 fractions including each hexane (HF), methanol-water (MF), n-butanol (BF) and water (WF) fractions. They were tested for anti-proliferative activity and cancer cell selectivity. The ME and fractions of G. superba which showed potent anti-proliferative activity were further examined for morphological changes and apoptotic activities by acridine orange (AO)/ethidium bromide (EB) staining. The ME of G. superba root showed active with the highest anti-proliferative activity at 9.17 and 1.58 folds of cisplatin and doxorubicin, respectively. After liquid-liquid partition, HF of V. denticulata, MFs of F. tinctoria, V. denticulata and BF of P. tetragonolobus showed higher anti-proliferative activities than their MEs. The MF of G. superba indicated the highest anti-proliferative activity at 7.73 and 1.34 folds of cisplatin and doxorubicin, respectively, but only 0.86 fold of its ME. The ME and HF, MF and BF of G. superba and MF of F. tinctoria demonstrated high cancer cell selectivity. At 50 µg/ml, ME, HF, MF and BF of G. superba demonstrated higher apoptotic activities than the two standard drugs. This present study has not only confirmed the traditional use of the Thai/Lanna medicinal plant recipes for cancer treatments, but also the potential of the selected plant, G. superba for the further development as a modern anti-cancer drug. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Performance and Stability Analyses of Rocket Thrust Chambers with Oxygen/Methane Propellants

NASA Technical Reports Server (NTRS)

Hulka, James R.; Jones, Gregg W.

2010-01-01

Liquid rocket engines using oxygen and methane propellants are being considered by the National Aeronautics and Space Administration (NASA) for future in-space vehicles. This propellant combination has not been previously used in flight-qualified engine systems developed by NASA, so limited test data and analysis results are available at this stage of early development. As part of activities for the Propulsion and Cryogenic Advanced Development (PCAD) project funded under the Exploration Technology Development Program, the NASA Marshall Space Flight Center (MSFC) has been evaluating capability to model combustion performance and stability for oxygen and methane propellants. This activity has been proceeding for about two years and this paper is a summary of results to date. Hot-fire test results of oxygen/methane propellant rocket engine combustion devices for the modeling investigations have come from several sources, including multi-element injector tests with gaseous methane from the 1980s, single element tests with gaseous methane funded through the Constellation University Institutes Program, and multi-element injector tests with both gaseous and liquid methane conducted at the NASA MSFC funded by PCAD. For the latter, test results of both impinging and coaxial element injectors using liquid oxygen and liquid methane propellants are included. Configurations were modeled with two one-dimensional liquid rocket combustion analysis codes, the Rocket Combustor Interactive Design and Analysis code and the Coaxial Injector Combustion Model. Special effort was focused on how these codes can be used to model combustion and performance with oxygen/methane propellants a priori, and what anchoring or calibrating features need to be applied, improved or developed in the future. Low frequency combustion instability (chug) occurred, with frequencies ranging from 150 to 250 Hz, with several multi-element injectors with liquid/liquid propellants, and was modeled using techniques from Wenzel and Szuch. High-frequency combustion instability also occurred at the first tangential (1T) mode, at about 4500 Hz, with several multi-element injectors with liquid/liquid propellants. Analyses of the transverse mode instability were conducted by evaluating injector resonances and empirical methods developed by Hewitt.

Synthesis of Mesoporous Carbons from Rice Husk for Supercapacitors with High Energy Density in Ionic Liquid Electrolytes.

PubMed

He, Xiaojun; Zhang, Hebao; Xie, Kang; Xia, Youyi; Zhao, Zhigang; Wang, Xiaoting

2016-03-01

High-performance mesoporous carbons (MCs) for supercapacitors were made from rice husk by one-step microwave-assisted ZnCl2 activation. The microstructures of MCs as-made were characterized by field emission scanning electron microscopy and transmission electron microscopy. The pore structure parameters of MCs were obtained by N2 adsorption technique. The electrochemical properties of MC electrodes were studied by constant current charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy in different electrolytes. The results showed that the specific surface area of MC4 made at the ZnCl2/rice husk mass of 4:1 reached 1737 m2 g(-1). The specific capacitance and energy density of the electrodes fabricated from the mixture of MC4 and microporous carbon increased with the mass percentage of MC4, reaching 157 F g(-1) and 84 Wh kg(-1) at 0.05 A g(-1), and showed good cycle stability in 1-butyl-3-methylimidazolium hexafluorophosphate electrolyte. Compared to the often-used aqueous and organic electrolytes, MC4 capacitor exhibited extremely high energy density in ionic liquid electrolyte, remaining at 28 Wh kg(-1) at 1684 W kg(-1). This work paves a new way to produce cost-effective MCs from biomass for supercapacitors with extremely high energy density in ionic liquid electrolytes.

AsS melt under pressure: one substance, three liquids.

PubMed

Brazhkin, V V; Katayama, Y; Kondrin, M V; Hattori, T; Lyapin, A G; Saitoh, H

2008-04-11

An in situ high-temperature--high-pressure study of liquid chalcogenide AsS by x-ray diffraction, resistivity measurements, and quenching from melt is presented. The obtained data provide direct evidence for the existence in the melt under compression of two transformations: one is from a moderate-viscosity molecular liquid to a high-viscosity nonmetallic polymerized liquid at P approximately 1.6-2.2 GPa; the other is from the latter to a low-viscosity metallic liquid at P approximately 4.6-4.8 GPa. Upon rapid cooling, molecular and metallic liquids crystallize to normal and high-pressure phases, respectively, while a polymerized liquid is easily quenched to a new AsS glass. General aspects of multiple phase transitions in liquid AsS, including relations to the phase diagram of the respective crystalline, are discussed.

Antioxidative activities of 62 wild mushrooms from Nepal and the phenolic profile of some selected species.

PubMed

Tamrakar, Sonam; Tran, Hai Bang; Nishida, Marina; Kaifuchi, Satoru; Suhara, Hiroto; Doi, Katsumi; Fukami, Katsuya; Parajuli, Gopal Prasad; Shimizu, Kuniyoshi

2016-10-01

Mushrooms have garnered immense popularity for their nutritional as well as medicinal values. The therapeutic potential of mushrooms in Nepal, a country well known for its biodiversity and natural medicinal resources, remains largely unstudied. Therefore, this study attempts to unveil the antioxidative properties of Nepalese wild mushrooms. Sixty-two wild mushroom samples were collected from several forests in different parts of Nepal. Ethanol and water extracts of the dried samples were tested for their antioxidative activities using total phenolic content (TPC), oxygen radical absorbance capacity (ORAC) assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing power (RP) assays. Ethanol extracts of samples belonging to the order Hymenochaetales showed significantly high activity in all the assays. Inonotus clemensiae had an exceptionally high TPC of 643.2 mg gallic acid equivalent (GAE)/g extract and also exhibited the lowest EC50 values in DPPH (0.081 mg/mL), ABTS (0.409 mg/mL), and EC0.5 value in reducing power (RP; 0.031 mg/mL) assays. High-performance liquid chromatography (HPLC) analysis of the top ten samples with the highest TPC was done to identify the phenolic compounds in the extracts, followed by liquid chromatography-mass spectrometry (LC-MS) analysis for some unknown compounds. These findings highlight the very strong antioxidative activity of Nepalese mushrooms, and paves the way for further research to explore their economic potential.

High power density supercapacitors based on the carbon dioxide activated D-glucose derived carbon electrodes and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid

NASA Astrophysics Data System (ADS)

Tooming, T.; Thomberg, T.; Kurig, H.; Jänes, A.; Lust, E.

2015-04-01

The electrochemical impedance spectroscopy, cyclic voltammetry, constant current charge/discharge and the constant power discharge methods have been applied to establish the electrochemical characteristics of the electrical double-layer capacitor (EDLC) consisting of the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) ionic liquid and microporous carbon electrodes. Microporous carbon material used for preparation of electrodes (GDAC - glucose derived activated carbon), has been synthesised from D-(+)-glucose by the hydrothermal carbonization method, including subsequent pyrolysis, carbon dioxide activation and surface cleaning step with hydrogen. The Brunauer-Emmett-Teller specific surface area (SBET = 1540 m2 g-1), specific surface area calculated using the non-local density functional theory in conjunction with stable adsorption integral equation using splines (SAIEUS) model SSAIEUS = 1820 m2 g-1, micropore surface area (Smicro = 1535 m2 g-1), total pore volume (Vtot = 0.695 cm3 g-1) and the pore size distribution were obtained from the N2 sorption data. The SBET, Smicro and Vtot values have been correlated with the electrochemical characteristics strongly dependent on the carbon activation conditions applied for EDLCs. Wide region of ideal polarizability (ΔV ≤ 3.2 V), very short charging/discharging time constant (2.7 s), and high specific series capacitance (158 F g-1) have been calculated for the optimized carbon material GDAC-10h (activation of GDAC with CO2 during 10 h) in EMImBF4 demonstrating that this system can be used for completing the EDLC with high energy- and power densities.

Rapid screening of transferrin-binders in the flowers of Bauhinia blakeana Dunn by on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-transferrin-fluorescence detection system.

PubMed

Liu, Meixian; Dong, Jing; Lin, Zongtao; Niu, Yanyan; Zhang, Xiaotian; Jiang, Haixiu; Guo, Ning; Li, Wei; Wang, Hong; Chen, Shizhong

2016-06-10

Transferrin (Transferrin, TRF, TF) has drawn increasing attention in cancer therapy due to its potential applications in drug delivery. TF receptor, highly expressed in tumor cells, recognizes and transports Fe(3+)-TF into cells to release iron into cytoplasm. Thus, discovering TF-binding compounds has become an active research area and is of great importance for target therapy. In this study, an on-line analysis method was established for screening TF-binding compounds from the flowers of Bauhinia blakeana Dunn using a high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-transferrin-fluorescence detector (HPLC-DAD-MS(n)-TF-FLD) method. As a result, 33 of 80 identified or tentatively characterized compounds in the sample were TF-binding active. Twenty-five flavonol glycosides and eight phenolic acids were identified as TF-binders. Twelve of these active compounds together with six standard compounds were used to study the dose-response effects and structure-activity relationships of flavonoids and phenolic acids. The method was validated by vitexin with a good linearity in the range of concentrations used in the study. The limit of detection for vitexin was 0.1596 nmol. Our study indicated that the established method is simple, rapid and sensitive for screening TF-binding active compounds in the extract of Bauhinia blakeana Dunn, and therefore is important for discovering potential anti-cancer ingredients from complex samples for TF related drug delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

A novel method for rapid in vitro radiobioassay

NASA Astrophysics Data System (ADS)

Crawford, Evan Bogert

Rapid and accurate analysis of internal human exposure to radionuclides is essential to the effective triage and treatment of citizens who have possibly been exposed to radioactive materials in the environment. The two most likely scenarios in which a large number of citizens would be exposed are the detonation of a radiation dispersal device (RDD, "dirty bomb") or the accidental release of an isotope from an industrial source such as a radioisotopic thermal generator (RTG). In the event of the release and dispersion of radioactive materials into the environment in a large city, the entire population of the city -- including all commuting workers and tourists -- would have to be rapidly tested, both to satisfy the psychological needs of the citizens who were exposed to the mental trauma of a possible radiation dose, and to satisfy the immediate medical needs of those who received the highest doses and greatest levels of internal contamination -- those who would best benefit from rapid, intensive medical care. In this research a prototype rapid screening method to screen urine samples for the presence of up to five isotopes, both individually and in a mixture, has been developed. The isotopes used to develop this method are Co-60, Sr-90, Cs-137, Pu-238, and Am-241. This method avoids time-intensive chemical separations via the preparation and counting of a single sample on multiple detectors, and analyzing the spectra for isotope-specific markers. A rapid liquid-liquid separation using an organic extractive scintillator can be used to help quantify the activity of the alpha-emitting isotopes. The method provides quantifiable results in less than five minutes for the activity of beta/gamma-emitting isotopes when present in the sample at the intervention level as defined by the Centers for Disease Control and Prevention (CDC), and quantifiable results for the activity levels of alpha-emitting isotopes present at their respective intervention levels in approximately 30 minutes of sample preparation and counting time. Radiation detector spectra -- e.g. those from high-purity germanium (HPGe) gamma detectors and liquid scintillation detectors -- which contain decay signals from multiple isotopes often have overlapping signals: the counts from one isotope's decay can appear in energy channels associated with another isotope's decay, complicating the calculation of each isotope's activity. The uncertainties associated with analyzing these spectra have been traced in order to determine the effects of one isotope's count rate on the sensitivity and uncertainty associated with each other isotope. The method that was developed takes advantage of activated carbon filtration to eliminate quenching effects and to make the liquid scintillation spectra from different urine samples comparable. The method uses pulse-shape analysis to reduce the interference from beta emitters in the liquid scintillation spectrum and improve the minimum detectable activity (MDA) and minimum quantifiable activity (MQA) for alpha emitters. The method uses an HPGe detector to quantify the activity of gamma emitters, and subtract their isotopes' contributions to the liquid scintillation spectra via a calibration factor, such that the pure beta and pure alpha emitters can be identified and quantified from the resulting liquid scintillation spectra. Finally, the method optionally uses extractive scintillators to rapidly separate the alpha emitters from the beta emitters when the activity from the beta emitters is too great to detect or quantify the activity from the alpha emitters without such a separation. The method is able to detect and quantify all five isotopes, with uncertainties and biases usually in the 10-40% range, depending upon the isotopic mixtures and the activity ratios between each of the isotopes.

Experimental And Theoretical High Energy Physics Research At UCLA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cousins, Robert D.

2013-07-22

This is the final report of the UCLA High Energy Physics DOE Grant No. DE-FG02- 91ER40662. This report covers the last grant project period, namely the three years beginning January 15, 2010, plus extensions through April 30, 2013. The report describes the broad range of our experimental research spanning direct dark matter detection searches using both liquid xenon (XENON) and liquid argon (DARKSIDE); present (ICARUS) and R&D for future (LBNE) neutrino physics; ultra-high-energy neutrino and cosmic ray detection (ANITA); and the highest-energy accelerator-based physics with the CMS experiment and CERN’s Large Hadron Collider. For our theory group, the report describesmore » frontier activities including particle astrophysics and cosmology; neutrino physics; LHC interaction cross section calculations now feasible due to breakthroughs in theoretical techniques; and advances in the formal theory of supergravity.« less

Acoustic Levitation Containerless Processing

NASA Technical Reports Server (NTRS)

Whymark, R. R.; Rey, C. A.

1985-01-01

This research program consists of the development of acoustic containerless processing systems with applications in the areas of research in material sciences, as well as the production of new materials, solid forms with novel and unusual microstructures, fusion target spheres, and improved optical fibers. Efforts have been focused on the containerless processing at high temperatures for producing new kinds of glasses. Also, some development has occurred in the areas of containerlessly supporting liquids at room temperature, with applications in studies of fluid dynamics, potential undercooling of liquids, etc. The high temperature area holds the greatest promise for producing new kinds of glasses and ceramics, new alloys, and possibly unusual structural shapes, such as very uniform hollow glass shells for fusion target applications. High temperature acoustic levitation required for containerless processing has been demonstrated in low-g environments as well as in ground-based experiments. Future activities include continued development of the signals axis acoustic levitator.

The ergonomics approach for thin film transistor-liquid crystal display manufacturing process.

PubMed

Lu, Chih-Wei; Yao, Chia-Chun; Kuo, Chein-Wen

2012-01-01

The thin film transistor-liquid crystal display (TFT-LCD) has been used all over the world. Although the manufacture process of TFT-LCD was highly automated, employees are hired to do manual job in module assembly process. The operators may have high risk of musculoskeletal disorders because of the long work hours and the repetitive activities in an unfitted work station. The tools of this study were questionnaire, checklist and to evaluate the work place design. The result shows that the participants reported high musculoskeletal disorder symptoms in shoulder (59.8%), neck (49.5%), wrist (39.5%), and upper back (30.6%). And, to reduce the ergonomic risk factors, revising the height of the work benches, chairs and redesigning the truck to decrease the chance of unsuitable positions were recommended and to reduce other ergonomics hazards and seta good human machine interface and appropriate job design.

Ethanolic extraction, purification, and partial characterization of a fluorescent toxin from the coral reef crab, Lophozozymus pictor.

PubMed

Lau, C O; Tan, C H; Khoo, H E; Li, Q T; Yuen, R

1995-01-01

A purification procedure for Lophozozymus pictor toxin (LPTX) following ethanolic extraction of whole crab homogenate is described. The ethanol-extracted toxin (LPTX-E) had higher yield and specific activity than the hot aqueous-extracted one (LPTX-H). It was found that LPTX-E was fluorescent and cochromatographed with LPTX-H on two-dimensional thin-layer chromatography. Although LPTX-E, LPTX-H, and palytoxin (P. caribaeorum, PTX) had similar migration and retention times when analysed on high performance capillary electrophoresis and gel permeation-high performance liquid chromatography respectively, LPTX-E and LPTX-H were both fluorescent in contrast to PTX. In addition, LPTX-E had a different retention time compared with PTX when chromatographed on reversed phase high performance liquid chromatography in the solvent system 80% acetonitrile and 0.02 M Tris-HCl, pH 7.2, at a 4:1 ratio, respectively, indicating some differences in their chemical structures.

Theoretical Studies of Nonuniform Orientational Order in Liquid Crystals and Active Particles

NASA Astrophysics Data System (ADS)

Duzgun, Ayhan

I investigate three systems that exhibit complex patterns in orientational order, which are controlled by geometry interacting with the dynamics of phase transitions, metastability, and activity. 1. Liquid Crystal Elastomers: Liquid-crystal elastomers are remarkable materials that combine the elastic properties of cross-linked polymer networks with the anisotropy of liquid crystals. Any distortion of the polymer network affects the nematic order of the liquid crystal, and, likewise, any change in the magnitude or direction of the nematic order influences the shape of the elastomer. When elastomers are prepared without any alignment, they develop disordered polydomain structures as they are cooled into the nematic phase. To model these polydomain structures, I develop a dynamic theory for the isotropic-nematic transition in elastomers. 2. Active Brownian Particles: Unlike equilibrium systems, active matter is not governed by the conventional laws of thermodynamics. I perform Langevin dynamics simulations and analytic calculations to explore how systems cross over from equilibrium to active behavior as the activity is increased. Based on these results, I calculate how the pressure depends on wall curvature, and hence make analytic predictions for the motion of curved tracers and other effects of confinement in active matter systems. 3. Skyrmions in Liquid Crystals: Skyrmions are localized topological defects in the orientation of an order parameter field, without a singularity in the magnitude of the field. For many years, such defects have been studied in the context of chiral liquid crystals--for example, as bubbles in a confined cholesteric phase or as double-twist tubes in a blue phase. More recently, skyrmions have been investigated extensively in the context of chiral magnets. In this project, I compare skyrmions in chiral liquid crystals with the analogous magnetic defects. Through simulations based on the nematic order tensor, I model both isolated skyrmions and periodic defect lattices.

A critical review of liquid helium temperature high frequency pulse tube cryocoolers for space applications

NASA Astrophysics Data System (ADS)

Wang, B.; Gan, Z. H.

2013-08-01

The importance of liquid helium temperature cooling technology in the aerospace field is discussed, and the results indicate that improving the efficiency of liquid helium cooling technologies, especially the liquid helium high frequency pulse tube cryocoolers, is the principal difficulty to be solved. The state of the art and recent developments of liquid helium high frequency pulse tube cryocoolers are summarized. The main scientific challenges for high frequency pulse tube cryocoolers to efficiently reach liquid helium temperatures are outlined, and the research progress addressing those challenges are reviewed. Additionally some possible solutions to the challenges are pointed out and discussed.

Antiviral active peptide from oyster

NASA Astrophysics Data System (ADS)

Zeng, Mingyong; Cui, Wenxuan; Zhao, Yuanhui; Liu, Zunying; Dong, Shiyuan; Guo, Yao

2008-08-01

An active peptide against herpes virus was isolated from the enzymic hydrolysate of oyster ( Crassostrea gigas) and purified with the definite direction hydrolysis technique in the order of alcalase and bromelin. The hydrolysate was fractioned into four ranges of molecular weight (>10 kDa, 10 5 kDa, 5 1 kDa and <1 kDa) using ultrafiltration membranes and dialysis. The fraction of 10 5 kDa was purified using consecutive chromatographic methods including DEAE Sephadex A-25 column, Sephadex G-25 column, and high performance liquid chromatogram (HPLC) by activity-guided isolation. The antiviral effect of the obtained peptide on herpetic virus was investigated in Vero cells by observing cytopathic effect (CPE). The result shows that the peptide has high inhibitory activity on herpetic virus.

High Resolution NMR Studies of Encapsulated Proteins In Liquid Ethane

PubMed Central

Peterson, Ronald W.; Lefebvre, Brian G.; Wand, A. Joshua

2005-01-01

Many of the difficulties presented by large, aggregation-prone, and membrane proteins to modern solution NMR spectroscopy can be alleviated by actively seeking to increase the effective rate of molecular reorientation. An emerging approach involves encapsulating the protein of interest within the protective shell of a reverse micelle, and dissolving the resulting particle in a low viscosity fluid, such as the short chain alkanes. Here we present the encapsulation of proteins with high structural fidelity within reverse micelles dissolved in liquid ethane. The addition of appropriate co-surfactants can significantly reduce the pressure required for successful encapsulation. At these reduced pressures, the viscosity of the ethane solution is low enough to provide sufficiently rapid molecular reorientation to significantly lengthen the spin-spin NMR relaxation times of the encapsulated protein. PMID:16028922

The influence of pore size and surface area of activated carbons on the performance of ionic liquid based supercapacitors.

PubMed

Pohlmann, Sebastian; Lobato, Belén; Centeno, Teresa A; Balducci, Andrea

2013-10-28

This study analyses and compares the behaviour of 5 commercial porous carbons in the ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) and its mixture with propylene carbonate (PC) as electrolytes. The results of this investigation show that the existence of a distribution of pore sizes and/or constrictions at the entrance of the pores leads to significant changes in the specific capacitance of the investigated materials. The use of PYR14TFSI as an electrolyte has a positive effect on the EDLC energy storage, but its high viscosity limits the power density. The mixture 50 : 50 wt% propylene carbonate-PYR14TFSI provides high operative voltage as well as low viscosity and thus notably enhances EDLC operation.

Fundamental Researches on the High-speed and High-efficiency Steelmaking Reaction

NASA Astrophysics Data System (ADS)

Kitamura, Shin-ya; Shibata, Hiroyuki; Maruoka, Nobuhiro

2012-06-01

Traditionally, steelmaking reactions have been analyzed by thermodynamics. Recently, software packages that can be used to calculate the equilibrium conditions have improved greatly. In some cases, information obtained in this software is useful for analyzing the steelmaking reaction. On the other hand, in industrial operation, steelmaking reactions, i.e., decarburization, dephosphorization, desulfurization or nitrogen removal, do not reach the equilibrium condition. Therefore, the kinetic model is very important for gaining a theoretical understanding of the steelmaking reaction. In this paper, the following recent research activities were shown; 1) mass transfer of impurities between solid oxide and liquid slag, 2) simulation model of hot metal dephosphorization by multiphase slag, 3) evaluation of reaction rate at bath surface in gas-liquid reaction system and 4) condition for forming of metal emulsion by bottom bubbling.

Direct analysis of prostaglandin-E2 and -D2 produced in an inflammatory cell reaction and its application for activity screening and potency evaluation using turbulent flow chromatography liquid chromatography-high resolution mass spectrometry.

PubMed

Shin, Jeong-Sook; Peng, Lei; Kang, Kyungsu; Choi, Yongsoo

2016-09-09

Direct analysis of prostaglandin-E2 (PGE2) and -D2 (PGD2) produced from a RAW264.7 cell-based reaction was performed by liquid chromatography high-resolution mass spectrometry (LC-HRMS), which was online coupled with turbulent flow chromatography (TFC). The capability of this method to accurately measure PG levels in cell reaction medium containing cytokines or proteins as a reaction byproduct was cross-validated by two conventional methods. Two methods, including an LC-HRMS method after liquid-liquid extraction (LLE) of the sample and a commercial PGE2 enzyme-linked immunosorbent assay (ELISA), showed PGE2 and/or PGD2 levels almost similar to those obtained by TFC LC-HRMS over the reaction time after LPS stimulation. After the cross-validation, significant analytical throughputs, allowing simultaneous screening and potency evaluation of 80 natural products including 60 phytochemicals and 20 natural product extracts for the inhibition of the PGD2 produced in the cell-based inflammatory reaction, were achieved using the TFC LC-HRMS method developed. Among the 60 phytochemicals screened, licochalcone A and formononetin inhibited PGD2 production the most with IC50 values of 126 and 151nM, respectively. For a reference activity, indomethacin and diclofenac were used, measuring IC50 values of 0.64 and 0.21nM, respectively. This method also found a butanol extract of Akebia quinata Decne (AQ) stem as a promising natural product for PGD2 inhibition. Direct and accurate analysis of PGs in the inflammatory cell reaction using the TFC LC-HRMS method developed enables the high-throughput screening and potency evaluation of as many as 320 samples in less than 48h without changing a TFC column. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis and characterization of NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst for hydrogenation reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karaoğlu, E., E-mail: ekaraoglu@fatih.edu.tr; Özel, U.; Caner, C.

2012-12-15

Graphical abstract: Display Omitted Highlights: ► Novel superparamagnetic NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst was fabricated through co-precipitation. ► It could be reused several times without significant loss in catalytic activity for hydrogenation reaction. ► No further modification of the NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst is necessary for utilization as catalyst. -- Abstract: Herein we report the fabrication and characterization magnetically recyclable catalysts of NiFe{sub 2}O{sub 4}–Pd nanocomposite as highly effective catalysts for reduction reactions in liquid phase. The reduction Pd{sup 2+} was accomplished with polyethylene glycol 400 (PEG-400) instead of sodium borohydride (NaBH{sub 4}) and NiFe{sub 2}O{sub 4}more » nanoparticles was prepared by sonochemically using FeCI{sub 3}·6H{sub 2}O and NiCl{sub 2}. The chemical characterization of the product was done with X-ray diffractometry, Infrared spectroscopy, transmission electron microscopy, UV–Vis spectroscopy, thermal gravimetry and inductively coupled plasma. Thus formed NiFe{sub 2}O{sub 4}–Pd MRCs showed a very high activity in reduction reactions of 4-nitro aniline and 1,3-dinitrobenzene in liquid phase. It was found out that the catalytic activity of NiFe{sub 2}O{sub 4}–Pd MRCs on the reduction of 4-nitro aniline and 1,3-dinitrobenzene in liquid phase are between 99–93% and 98–93%, respectively. Magnetic character of this system allowed recovery and multiple use without significant loss of its catalytic activity. It is found that NiFe{sub 2}O{sub 4}–Pd MRCs showed very efficient catalytic activity and multiple usability.« less

First Results of the Testing of the Liquid Gallium Jet Limiter Concept for ISTTOK

NASA Astrophysics Data System (ADS)

Gomes, R. B.; Fernandes, H.; Silva, C.; Borba, D.; Carvalho, B.; Varandas, C.; Lielausis, O.; Klyukin, A.; Platacis, E.; Mikelsons, A.; Platnieks, I.

2006-12-01

The use of liquid metals as plasma facing components in tokamaks has recently experienced a renewed interest stimulated by their advantages to the development of a fusion reactor. Liquid metals have been proposed to solve problems related to the erosion and neutronic activation of solid walls submitted to high power loads allowing an efficient heat exhaustion from fusion devices. Presently the most promising materials are Lithium and Gallium. ISTTOK, a small size tokamak, will be used to test the behavior of a liquid Gallium jet in the vacuum chamber and its influence on the plasma. This paper presents a description of the conceived setup as well as experimental results. The liquid Gallium jet is generated by hydrostatic pressure and injected in a radial position close to a moveable stainless steel limiter. Both the jet and the limiter positions are variable allowing for a controlled exposure of the liquid Gallium to the edge plasma. The main components of the Gallium loop are a MHD pump, the liquid metal injector and a filtering system. The MHD pump is of the induction type, based on rotating permanent magnets. The injector is build from a ¼″ stainless steel pipe ended by a shaping nozzle. A setup has been developed to introduce oxide-free Gallium inside the loop's main supply tank. Raw liquid metal is placed inside a chamber heated and degassed under high vacuum while clean Gallium is extracted from the main body of the liquefied metal. Prior to installation on the tokamak, the experimental rig has been implemented using a Pyrex tube as test chamber to investigate the stability of the Gallium jet and its break-up length for several nozzle sizes. Results are presented in this paper. This rig was also useful to assess the behavior of the overall implemented apparatus.

Validation of a high-performance liquid chromatography method for thiopurine S-methyltransferase activity in whole blood using 6-mercaptopurine as substrate.

PubMed

Rieger, Hannah; Schmidt, Patrik; Schaeffeler, Elke; Abe, Manabu; Schiffhauer, Mira; Schwab, Matthias; von Ahsen, Nicolas; Zurek, Gabriela; Kirchherr, Hartmut; Shipkova, Maria; Wieland, Eberhard

2018-04-25

Variation in metabolism, toxicity and therapeutic efficacy of thiopurine drugs is largely influenced by genetic polymorphisms in the thiopurine S-methyltransferase (TPMT) gene. Determination of TPMT activity is routinely performed in patients to adjust drug therapy. We further optimized a previously established high-performance liquid chromatography (HPLC) method by measuring TPMT activity in whole blood instead of isolated erythrocytes, which is based on conversion of 6-mercaptopurine to 6-methylmercaptopurine using S-adenosyl-methionine as methyl donor. The simplified TPMT whole-blood method showed similar or better analytical and diagnostic performance compared with the former erythrocyte assay. The whole-blood method was linear for TPMT activities between 0 and 40 nmol/(mL·h) with a quantification limit of 0.1 nmol/(mL·h). Within-day imprecision and between-day imprecision were ≤5.1% and ≤8.5%, respectively. The optimized method determining TPMT activity in whole blood (y) showed agreement with the former method determining TPMT activity in erythrocytes (x) (n=45, y=1.218+0.882x; p>0.05). Phenotype-genotype concordance (n=300) of the whole-blood method was better when TPMT activity was expressed per volume of whole blood (specificity 92.2%), whereas correction for hematocrit resulted in lower genotype concordance (specificity 86.9%). A new cutoff for the whole-blood method to distinguish normal from reduced TPMT activity was determined at ≤6.7 nmol/(mL·h). This optimized TPMT phenotyping assay from whole blood using 6-MP as substrate is suitable for research and routine clinical analysis.

UHPLC-UV method for the determination of flavonoids in dietary supplements and for evaluation of their antioxidant activities.

PubMed

Magiera, Sylwia; Baranowska, Irena; Lautenszleger, Anna

2015-01-01

A simple and rapid ultra-high performance liquid chromatographic (UHPLC) method coupled with an ultraviolet detector (UV) has been developed and validated for the separation and determination of 14 major flavonoids ((±)-catechin, (-)-epicatechin, glycitin, (-)-epicatechin gallate, rutin, quercitrin, hesperidine, neohesperidine, daidzein, glycitein, quercetin, genistein, hesperetin, and biochanin A) in herbal dietary supplements. The flavonoids have been separated on a Chromolith Fast Gradient Monolithic RP-18e column utilizing a mobile phase composed of 0.05% trifluoroacetic acid in water and acetonitrile in gradient elution mode. Under these conditions, flavonoids were separated in a 5 min run. The selectivity of the developed UHPLC-UV method was confirmed by comparison with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The validation parameters such as linearity, sensitivity, precision, and accuracy were found to be highly satisfactory. The optimized method was applied to determination of flavonoids in different dietary supplements. Additionally, the developed HPLC-UV method combined with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay was used in the evaluation of antioxidant activity of the selected flavonoids. Copyright © 2014 Elsevier B.V. All rights reserved.

Microscopy illumination engineering using a low-cost liquid crystal display.

PubMed

Guo, Kaikai; Bian, Zichao; Dong, Siyuan; Nanda, Pariksheet; Wang, Ying Min; Zheng, Guoan

2015-02-01

Illumination engineering is critical for obtaining high-resolution, high-quality images in microscope settings. In a typical microscope, the condenser lens provides sample illumination that is uniform and free from glare. The associated condenser diaphragm can be manually adjusted to obtain the optimal illumination numerical aperture. In this paper, we report a programmable condenser lens for active illumination control. In our prototype setup, we used a $15 liquid crystal display as a transparent spatial light modulator and placed it at the back focal plane of the condenser lens. By setting different binary patterns on the display, we can actively control the illumination and the spatial coherence of the microscope platform. We demonstrated the use of such a simple scheme for multimodal imaging, including bright-field microscopy, darkfield microscopy, phase-contrast microscopy, polarization microscopy, 3D tomographic imaging, and super-resolution Fourier ptychographic imaging. The reported illumination engineering scheme is cost-effective and compatible with most existing platforms. It enables a turnkey solution with high flexibility for researchers in various communities. From the engineering point-of-view, the reported illumination scheme may also provide new insights for the development of multimodal microscopy and Fourier ptychographic imaging.

Preparation and electrochemical characterization of gel polymer electrolyte based on electrospun polyacrylonitrile nonwoven membranes for lithium batteries

NASA Astrophysics Data System (ADS)

Raghavan, Prasanth; Manuel, James; Zhao, Xiaohui; Kim, Dul-Sun; Ahn, Jou-Hyeon; Nah, Changwoon

Electrospun membranes of polyacrylonitrile are prepared, and the electrospinning parameters are optimized to get fibrous membranes with uniform bead-free morphology. The polymer solution of 16 wt.% in N, N-dimethylformamide at an applied voltage of 20 kV results in the nanofibrous membrane with average fiber diameter of 350 nm and narrow fiber diameter distribution. Gel polymer electrolytes are prepared by activating the nonwoven membranes with different liquid electrolytes. The nanometer level fiber diameter and fully interconnected pore structure of the host polymer membranes facilitate easy penetration of the liquid electrolyte. The gel polymer electrolytes show high electrolyte uptake (>390%) and high ionic conductivity (>2 × 10 -3 S cm -1). The cell fabricated with the gel polymer electrolytes shows good interfacial stability and oxidation stability >4.7 V. Prototype coin cells with gel polymer electrolytes based on a membrane activated with 1 M LiPF 6 in ethylene carbonate/dimethyl carbonate or propylene carbonate are evaluated for discharge capacity and cycle property in Li/LiFePO 4 cells at room temperature. The cells show remarkably good cycle performance with high initial discharge properties and low capacity fade under continuous cycling.

Online screening of nitric oxide scavengers in natural products using high performance liquid chromatography coupled with tandem diode array and fluorescence detection.

PubMed

Li, Dapeng; Wang, Ting; Guo, Yujie; Hu, Yuanjia; Yu, Boyang; Qi, Jin

2015-12-18

Nitric oxide (NO) is an important cellular signaling molecule with extensive physiological and pathophysiological effects. NO scavengers have the potential to treat inflammation, septic shock and other related diseases, and numerous examples have been chemically synthesized or isolated from natural products. The chemical diversity of natural products, however, means that a huge effort is necessary to efficiently screen and identify bioactive compounds, especially NO scavengers. In this article, we propose an effective analytical method to screen for NO scavengers in three natural products using an online system that couples high performance liquid chromatography with tandem diode array and fluorescence detection (HPLC-DAD-FLD). Eighteen compounds from radix of Scutellaria baicalensis Georgi and green tea displayed significant NO scavenging activity whereas components of Pueraria lobata (Willd.) Ohwi had no discernable activity. The structures of the active compounds were elucidated using Agilent Accurate-Mass Q-TOF LC/MS system. Preliminary analysis of structure-activity relationships indicated that, in flavonoids, a 2,3-double bond and a 3-H atom or a 3-OH group are essential for activity. In tannins, poly-hydroxyl groups are important for NO scavenging activity. Method validation indicated that the newly developed method is both reliable and repeatable. The online method that we present provides a simple, rapid and effective way to identify and characterize NO scavengers present in natural products. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessing the influence of NOx concentrations and relative humidity on secondary organic aerosol yields from α-pinene photo-oxidation through smog chamber experiments and modelling calculations

NASA Astrophysics Data System (ADS)

Stirnweis, Lisa; Marcolli, Claudia; Dommen, Josef; Barmet, Peter; Frege, Carla; Platt, Stephen M.; Bruns, Emily A.; Krapf, Manuel; Slowik, Jay G.; Wolf, Robert; Prévôt, Andre S. H.; Baltensperger, Urs; El-Haddad, Imad

2017-04-01

Secondary organic aerosol (SOA) yields from the photo-oxidation of α-pinene were investigated in smog chamber (SC) experiments at low (23-29 %) and high (60-69 %) relative humidity (RH), various NOx / VOC ratios (0.04-3.8) and with different aerosol seed chemical compositions (acidic to neutralized sulfate-containing or hydrophobic organic). A combination of a scanning mobility particle sizer and an Aerodyne high-resolution time-of-flight aerosol mass spectrometer was used to determine SOA mass concentration and chemical composition. We used a Monte Carlo approach to parameterize smog chamber SOA yields as a function of the condensed phase absorptive mass, which includes the sum of OA and the corresponding bound liquid water content. High RH increased SOA yields by up to 6 times (1.5-6.4) compared to low RH. The yields at low NOx / VOC ratios were in general higher compared to yields at high NOx / VOC ratios. This NOx dependence follows the same trend as seen in previous studies for α-pinene SOA. A novel approach of data evaluation using volatility distributions derived from experimental data served as the basis for thermodynamic phase partitioning calculations of model mixtures in this study. These calculations predict liquid-liquid phase separation into organic-rich and electrolyte phases. At low NOx conditions, equilibrium partitioning between the gas and liquid phases can explain most of the increase in SOA yields observed at high RH, when in addition to the α-pinene photo-oxidation products described in the literature, fragmentation products are added to the model mixtures. This increase is driven by both the increase in the absorptive mass and the solution non-ideality described by the compounds' activity coefficients. In contrast, at high NOx, equilibrium partitioning alone could not explain the strong increase in the yields with RH. This suggests that other processes, e.g. reactive uptake of semi-volatile species into the liquid phase, may occur and be enhanced at higher RH, especially for compounds formed under high NOx conditions, e.g. carbonyls.

Functionalization of carbon nanotubes with water-insoluble porphyrin in ionic liquid: direct electrochemistry and highly sensitive amperometric biosensing for trichloroacetic acid.

PubMed

Tu, Wenwen; Lei, Jianping; Ju, Huangxian

2009-01-01

A functional composite of single-walled carbon nanotubes (SWNTs) with hematin, a water-insoluble porphyrin, was first prepared in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]) ionic liquid. The novel composite in ionic liquid was characterized by scanning electron microscopy, ultraviolet absorption spectroscopy, and electrochemical impedance spectroscopy, and showed a pair of direct redox peaks of the Fe(III)/Fe(II) couple. The composite-[BMIM][PF(6)]-modified glassy carbon electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) in neutral media due to the synergic effect among SWNTs, [BMIM][PF(6)], and porphyrin, which led to a highly sensitive and stable amperometric biosensor for TCA with a linear range from 9.0x10(-7) to 1.4x10(-4) M. The detection limit was 3.8x10(-7) M at a signal-to-noise ratio of 3. The TCA biosensor had good analytical performance, such as rapid response, good reproducibility, and acceptable accuracy, and could be successfully used for the detection of residual TCA in polluted water. The functional composite in ionic liquid provides a facile way to not only obtain the direct electrochemistry of water-insoluble porphyrin, but also construct novel biosensors for monitoring analytes in real environmental samples.

High-performance liquid chromatographic method for the simultaneous determination of nalbuphine and its prodrug, sebacoyl dinalbuphine ester, in dog plasma and application to pharmacokinetic studies in dogs.

PubMed

Pao, L H; Hsiong, C H; Hu, O Y; Ho, S T

2000-09-15

For the determination of nalbuphine and its long acting prodrug, sebacoyl dinalbuphine ester (SDN), in biological samples, a reversed-phase high-performance liquid chromatographic method using dual detectors was established. Ultraviolet and fluorescence detectors were connected in series for determining SDN and nalbuphine, respectively. The two analytes and internal standard were extracted from plasma by alkaline liquid-liquid extraction using n-hexane-isoamyl alcohol (9:1, v/v). The calibration curve for nalbuphine was linear over the range from 10 to 2,500 ng/ml, while the range was 25 to 2,500 ng/ml for SDN. The within- and between-day precision and accuracy were all within 10% for both nalbuphine and SDN over these concentrations. The method was applied successfully to a pharmacokinetic study of SDN administered at 20 mg/kg to two beagle dogs. Pharmacokinetic analysis revealed that SDN followed a linear one-compartment model with an elimination half-life of 74.7 min. Formation of nalbuphine after intravenous administration of SDN was observed in the first time point sample (5 min). These results indicate that SDN is rapidly metabolized to its active moiety, nalbuphine, in dogs and no other metabolites are detected in plasma.

Control of spontaneous combustion of coal in goaf at high geotemperatureby injecting liquid carbon dioxide: inertand cooling characteristics of coal

NASA Astrophysics Data System (ADS)

Liu, Zhenling; Wen, Hu; Yu, Zhijin; Wang, Chao; Ma, Li

2018-02-01

The spontaneous combustion of coal in goaf at high geo temperatures is threatening safety production in coalmine. The TG-DSC is employed to study the variation of mass and energy at 4 atmospheres (mixed gases of N2, O2 and CO2) and heating rates (10°C/min) during oxidation of coal samples. The apparent activation energy and pre-exponential factor of coal oxidation decrease rapidly with increasing theCO2 concentration. Furthermore, its reaction rate is slow, its heat released reduces. Based on the conditions of 1301 face in the Longgucoalmine, a three-dimensional geometry model is developed to simulate the distributions stream field and temperature field and the variation characteristics ofCO2 concentration field after injecting liquidCO2. The results indicate that oxygen reached to depths of˜120m in goaf, 100m in the side of inlet air, and 10m in the side of outlet air before injecting liquidCO2. After injecting liquidCO2for 28.8min, the width of oxidation and heat accumulation zone is shortened by 20m, and the distance is 80m in the side of working face and 40˜60m in goafin the direction of dip affected by temperature.

Pharmacokinetics and tissue distribution study of Praeruptorin D from Radix peucedani in rats by high-performance liquid chromatography (HPLC).

PubMed

Liang, Taigang; Yue, Wenyan; Du, Xue; Ren, Luhui; Li, Qingshan

2012-01-01

Praeruptorin D (PD), a major pyranocoumarin isolated from Radix Peucedani, exhibited antitumor and anti-inflammatory activities. The aim of this study was to investigate the pharmacokinetics and tissue distribution of PD in rats following intravenous (i.v.) administration. The levels of PD in plasma and tissues were measured by a simple and sensitive reversed-phase high-performance liquid chromatography (HPLC) method. The biosamples were treated by liquid-liquid extraction (LLE) with methyl tert-butyl ether (MTBE) and osthole was used as the internal standard (IS). The chromatographic separation was accomplished on a reversed-phase C(18) column using methanol-water (75:25, v/v) as mobile phase at a flow rate of 0.8 mL/min and ultraviolet detection wave length was set at 323 nm. The results demonstrate that this method has excellent specificity, linearity, precision, accuracy and recovery. The pharmacokinetic study found that PD fitted well into a two-compartment model with a fast distribution phase and a relative slow elimination phase. Tissue distribution showed that the highest concentration was observed in the lung, followed by heart, liver and kidney. Furthermore, PD can also be detected in the brain, which indicated that PD could cross the blood-brain barrier after i.v. administration.

[Correction of schoolchildren's diets with biologically active additives].

PubMed

Diudiakov, A A; Rakhmanov, R S; Korotunov, Iu V; Gruzdeva, A E

2002-01-01

The actual nutrition of schoolchildren in the Nizni-Novgorod district is imbalanced due to the deficiency of protein and vitamins and to the high contents of fats and carbohydrates. The authors provide evidence for a combined preparation to correct the children's diets, which incorporates animal protein, biologically active plant additives, and egg-shell calcium. The use of the preparation in combination with liquid bifidumbacterin contributes to increases in morphofunctional parameters in adolescents.

Advanced adaptive optics technology development

NASA Astrophysics Data System (ADS)

Olivier, Scot S.

2002-02-01

The NSF Center for Adaptive Optics (CfAO) is supporting research on advanced adaptive optics technologies. CfAO research activities include development and characterization of micro-electro-mechanical systems (MEMS) deformable mirror (DM) technology, as well as development and characterization of high-resolution adaptive optics systems using liquid crystal (LC) spatial light modulator (SLM) technology. This paper presents an overview of the CfAO advanced adaptive optics technology development activities including current status and future plans.

Spacecraft active thermal control subsystem design and operation considerations

NASA Technical Reports Server (NTRS)

Sadunas, J. A.; Lehtinen, A. M.; Nguyen, H. T.; Parish, R.

1986-01-01

Future spacecraft missions will be characterized by high electrical power requiring active thermal control subsystems for acquisition, transport, and rejection of waste heat. These systems will be designed to operate with minimum maintenance for up to 10 years, with widely varying externally-imposed environments, as well as the spacecraft waste heat rejection loads. This paper presents the design considerations and idealized performance analysis of a typical thermal control subsystem with emphasis on the temperature control aspects during off-design operation. The selected thermal management subsystem is a cooling loop for a 75-kWe fuel cell subsystem, consisting of a fuel cell heat exchanger, thermal storage, pumps, and radiator. Both pumped-liquid transport and two-phase (liquid/vapor) transport options are presented with examination of similarities and differences of the control requirements for these representative thermal control options.

Fabrication and electrical characterization of silicon nanowires based resistors

NASA Astrophysics Data System (ADS)

Ni, L.; Demami, F.; Rogel, R.; Salaün, A. C.; Pichon, L.

2009-11-01

Silicon nanowires (SiNWs) are synthesized via the Vapor-Liquid-Solid (VLS) mechanism using gold (Au) as metal catalyst and silane (SiH4) as precursor gas. Au nanoparticles are employed as liquid droplets catalysis during the SiNWs growth performed in a hot wall LPCVD reactor at 480°C and 40 Pa. SiNWs local synthesis at micron scale is demonstrated using classical optical photolithography process. SiNWs grow with high density anchored at the dedicated catalyst islands. This resulting network is used to interconnect two heavily doped polysilicon interdigitated electrodes leading to the formation of electrical resistors in a coplanar structure. Current-voltage (I-V) characteristics highlight a symmetric shape. The temperature dependence of the electrical resistance is activated, with activation energy of 0.47 eV at temperatures greater than 300K.

Bioactive compounds, antioxidant potential, and hepatoprotective activity of sea cucumber (Holothuria atra) against thioacetamide intoxication in rats.

PubMed

Esmat, Amr Y; Said, Mahmoud M; Soliman, Amel A; El-Masry, Khaled S H; Badiea, Elham Abdel

2013-01-01

The identification of the active phenolic compounds in the mixed extract of sea cucumber (Holothuria atra) body wall by high-performance liquid chromatography and an assessment of its hepatoprotective activity against thioacetamide-induced liver fibrosis in rats. Female Swiss albino rats were divided into four groups: normal controls; oral administration of a sea cucumber mixed extract (14.4 mg/kg of body weight) on days 2, 4, and 6 weekly for 8 consecutive weeks; intoxication with thioacetamide (200 mg/kg of body weight, intraperitoneally) on days 2 and 6 weekly for 8 wk; and oral administration of a sea cucumber extract and then intoxication with thioacetamide 2 h later for 8 wk. High-performance liquid chromatographic analysis of the sea cucumber mixed extract revealed the presence of some phenolic components, such as chlorogenic acid, pyrogallol, rutin, coumaric acid, catechin, and ascorbic acid. In vitro studies have shown that the extract has a high scavenging activity for the nitric oxide radical, a moderate iron-chelating activity, and a weak inhibitory effect of lipid peroxidation. The subchronic oral administration of sea cucumber extract to the rats did not show any toxic side effects but increased hepatic superoxide dismutase and glutathione peroxidase activities. The coadministration of sea cucumber extract and thioacetamide (protection modality) normalized serum direct bilirubin, alanine and aspartate aminotransferases, hepatic malondialdehyde, and hydroxyproline concentrations and antioxidant enzyme activities. In addition, the histologic examination of liver sections from the protection group that were stained with hematoxylin and eosin showed substantial attenuation of the degenerative cellular changes and regressions in liver fibrosis and necrosis induced by the thioacetamide intoxication. Sea cucumber mixed extract contains physiologically active phenolic compounds with antioxidant activity, which afforded a potential hepatoprotective activity against thioacetamide-induced liver injury in a rat model. Copyright © 2013 Elsevier Inc. All rights reserved.

Qualitative characterization of Desmodium adscendens constituents by high-performance liquid chromatography-diode array ultraviolet-electrospray ionization multistage mass spectrometry.

PubMed

Baiocchi, Claudio; Medana, Claudio; Giancotti, Valeria; Aigotti, Riccardo; Dal Bello, Frederica; Massolino, Cristina; Gastaldi, Daniela; Grandi, Maurizio

2013-01-01

The many effects of the African medicinal herb Desmodium adscendens were studied in the 1980s and 1990s. In spite of this, a comprehensive analytical protocol for the quality control of its constituents (soyasaponins, alkaloids and flavonoids) has not yet been formulated and reported. This study deals with the optimization of extraction conditions from the plant and qualitative identification of the constituents by HPLC-diode array UV and multistage mass spectrometry. Plant constituents were extracted from leaves by liquid-liquid and solid matrix dispersion extraction. Separation was achieved via RP-C18 liquid chromatographywith UV and MS(n) detection and mass spectrometry analysis was conducted by electrospray ionization ion trap or orbitrap mass spectrometry. High resolution mass spectrometry (HRMS) was used for structural identification of active molecules relating to soyasaponins and alkaloids. The flavonoid fragmentations were preliminarily studied by HRMS in order to accurately characterize the more common neutral losses. However, the high number of isomeric species induced us to make recourse to a more extended chromatographic separation in order to enable useful tandem mass spectrometry and ultraviolet spectral interpretation to propose a reasonable chemical classification of these polyphenols. 35 compounds of this class were identified herein with respect to the five reported in literature in this way we made up a comprehensive protocol for the qualitative analysis of the high complexity content of this plant. This result paves the way for both reliable quality control of potential phytochemical medicaments and possible future systematic clinical studies.

Effects of Shock-Breakout Pressure on Ejection of Micron-Scale Material from Shocked Tin Surfaces

NASA Astrophysics Data System (ADS)

Zellner, Michael; Hammerberg, James; Hixson, Robert; Morley, Kevin; Obst, Andrew; Olson, Russell; Payton, Jeremy; Rigg, Paulo; Buttler, William; Grover, Michael; Iverson, Adam; Macrum, Gregory; Stevens, Gerald; Turley, William; Veeser, Lynn; Routley, Nathan

2007-06-01

Los Alamos National Lab (LANL) is actively engaged in the development of a model to predict the formation of micron-scale fragments ejected (ejecta) from shocked metal surfaces. The LANL ejecta model considers that the amount of ejecta is mainly related to the material's phase on shock release at the free-surface. This effort investigates the relation between ejecta production and shock-breakout pressure for Sn shocked with high explosives to pressures near the solid-on-release/partial-liquid-on-release phase transition region. We found that the amount of ejecta produced for shock-breakout pressures that resulted in partial-liquid-on-release increased significantly compared to that which resulted in solid-on-release. Additionally, we found that the amount of ejecta remained relatively constant within the partial-liquid-on-release, regardless of shock-breakout pressure.

Pressure Effects on the Ejection of Material from Shocked Tin Surfaces

NASA Astrophysics Data System (ADS)

Zellner, M. B.; Grover, M.; Hammerberg, J. E.; Hixson, R. S.; Iverson, A. J.; Macrum, G. S.; Morley, K. B.; Obst, A. W.; Olson, R. T.; Payton, J. R.; Rigg, P. A.; Routley, N.; Stevens, G. D.; Turley, W. D.; Veeser, L.; Buttler, W. T.

2007-12-01

Los Alamos National Lab (LANL) is actively engaged in the development of a model to predict the formation of micron-scale fragments ejected (ejecta) from shocked metals that have surface defects. The LANL ejecta model considers that the amount of ejecta is mainly related to the material's phase on shock release at the free-surface. This effort investigates the relation between ejecta production and shock-breakout pressure for Sn shocked with high explosives to pressures near the solid-on-release/partial-liquid-on-release phase transition region. We found that the amount of ejecta produced for shock-breakout pressures that resulted in partial-liquid-on-release increased significantly compared to that which resulted in solid-on-release. Additionally, we found that the amount of ejecta remained relatively constant within the partial-liquid-on-release, regardless of shock-breakout pressure.

HCl Vapour Pressures and Reaction Probabilities for ClONO2 + HCl on Liquid H2SO4-HNO3-HCl-H20 Solutions

NASA Technical Reports Server (NTRS)

Elrod, M. J.; Koch, R. E.; Kim, J. E.; Molina, M. J.

1995-01-01

Henry's Law solubility constants for HCl have been measured for liquid H2SO4-HNO3-HCl-H2O solutions; the results are in good agreement with predictions from published semiempirical models. The ClONO2 + HCl reaction on the surfaces of such solutions with compositions simulating those of stratospheric aerosols has been investigated; as the composition changes following the temperature drop characteristic of the high-latitude stratosphere the reaction probability gamma increases rapidly. Furthermore, the gamma values remain essentially unchanged when HN03 uptake is neglected; the controlling factor appears to be the solubility of HCl. These results corroborate our earlier suggestion that supercooled liquid sulfate aerosols promote chlorine activation at low temperatures as efficiently as solid polar stratospheric cloud particles.

Effect of silicon on activity coefficients of siderophile elements (Au, Pd, Pt, P, Ga, Cu, Zn, and Pb) in liquid Fe: Roles of core formation, late sulfide matte, and late veneer in shaping terrestrial mantle geochemistry

NASA Astrophysics Data System (ADS)

Righter, K.; Pando, K.; Humayun, M.; Waeselmann, N.; Yang, S.; Boujibar, A.; Danielson, L. R.

2018-07-01

Earth's core contains ∼10% of a light element that may be a combination of Si, S, C, O or H, with Si potentially being the major light element. Metal-silicate partitioning of siderophile elements can place important constraints on the P-T-fO2 and composition of the early Earth, but the effect of Si alloyed in Fe liquids is unknown for many of these elements. In particular, the effect of Si on the partitioning of highly siderophile elements (Au, Re and PGE) is virtually unknown. To address this gap in understanding, we have undertaken a systematic study of the highly siderophile elements Au, Pd, and Pt, and the volatile siderophile elements P, Ga, Cu, Zn, and Pb at variable Si content of metal, and 1600 °C and 1 GPa. From our experiments we derive epsilon interaction parameters between these elements and Si in Fe metallic liquids. The new parameters are used to update an activity model for trace siderophile elements in Fe alloys; Si causes large variation in the magnitude of activity coefficients of these elements in FeSi liquids. Because the interaction parameters are all positive, Si causes a decrease in their metal/silicate partition coefficients. We combine these new activity results with experimental studies of Au, Pd, Pt, P, Ga, Cu, Zn and Pb, to derive predictive expressions for metal/silicate partition coefficients which can then be applied to Earth. The expressions are applied to two scenarios for continuous accretion of Earth; specifically for constant and increasing fO2 during accretion. The results indicate that mantle concentrations of P, Ga, Cu, Zn, and Pb can be explained by metal-silicate equilibrium during accretion of the Earth where Earth's early magma ocean deepens to pressures of 40-60 GPa. Au, Pd, and Pt, on the other hand become too high in the mantle in such a scenario, and require a later removal mechanism, rather than an addition as traditionally argued. A late reduction event that removes 0.5% metal from a shallow magma ocean can lower the Au, Pd, and Pt contents to values near the current day BSE. On the other hand, removal of 0.2-1.0% of a late sulfide-rich matte to the core would lower the Au, Pd, and Pt concentrations in the mantle, but not to chondritic relative concentrations observed in the BSE. If sulfide matte is called upon to remove HSEs, they must be later added via a late veneer to re-establish the high and chondritic relative PUM concentrations. These results suggest that although accretion and core formation (involving a Si, S, and C-bearing metallic liquid) were the primary processes establishing many of Earth's mantle volatile elements and HSE, a secondary removal process is required to establish HSEs at their current and near-chondritic relative BSE levels. Mn and P - two siderophile elements that are central to biochemical processes (photosynthesis and triphosphates, respectively) - have significant and opposite interactions with FeSi liquids, and their mantle concentrations would be notably different if Earth had a Si-free core.

Removal of novel antiandrogens identified in biological effluents of domestic wastewater by activated carbon.

PubMed

Ma, Dehua; Chen, Lujun; Liu, Rui

2017-10-01

Environmental antiandrogenic (AA) contaminants in effluents from wastewater treatment plants have the potential for negative impacts on wildlife and human health. The aim of our study was to identify chemical contaminants with likely AA activity in the biological effluents and evaluate the removal of these antiandrogens (AAs) during advanced treatment comprising adsorption onto granular activated carbon (GAC). In this study, profiling of AA contaminants in biological effluents and tertiary effluents was conducted using effect-directed analysis (EDA) including high performance liquid chromatography (HPLC) fractionation, a recombinant yeast screen containing androgen receptor (YAS), in combination with mass spectrometry analyses. Analysis of a wastewater secondary effluent from a membrane bioreactor revealed complex profiles of AA activity comprising 14 HPLC fractions and simpler profiles of GAC effluents with only 2 to 4 moderately polar HPLC fractions depending on GAC treatment conditions. Gas chromatography-mass spectrometry and ultra-high performance liquid chromatography-nanospray mass spectrometry analyses of AA fractions in the secondary effluent resulted in detection of over 10 chemical contaminants, which showed inhibition of YAS activity and were potential AAs. The putative AAs included biocides, food additives, flame retardants, pharmaceuticals and industrial contaminants. To our knowledge, it is the first time that the AA properties of N-ethyl-2-isopropyl-5-methylcyclohexanecarboxamide (WS3), cetirizine, and oxcarbazepine are reported. The EDA used in this study was proven to be a powerful tool to identify novel chemical structures with AA activity in the complex aquatic environment. The adsorption process to GAC of all the identified antiandrogens, except WS3 and triclosan, fit well with the pseudo-second order kinetics models. Adsorption to GAC could further remove most of the AAs identified in the biological effluents with high efficiencies. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of isoxaflutole (balance) and its metabolites in water using solid phase extraction followed by high-performance liquid chromatography with ultraviolet or mass spectrometry

USGS Publications Warehouse

Lin, Chung-Ho; Lerch, Robert N.; Thurman, E. Michael; Garrett , Harold E.; George, Milon F.

2002-01-01

Balance (isoxaflutole, IXF) belongs to a new family of herbicides referred to as isoxazoles. IXF has a very short soil half-life (<24 h), degrading to a biologically active diketonitrile (DKN) metabolite that is more polar and considerably more stable. Further degradation of the DKN metabolite produces a nonbiologically active benzoic acid (BA) metabolite. Analytical methods using solid phase extraction followed by high-performance liquid chromatography−UV (HPLC-UV) or high-performance liquid chromatography−mass spectrometry (HPLC-MS) were developed for the analysis of IXF and its metabolites in distilled deionized water and ground water samples. To successfully detect and quantify the BA metabolite by HPLC-UV from ground water samples, a sequential elution scheme was necessary. Using HPLC-UV, the mean recoveries from sequential elution of the parent and its two metabolites from fortified ground water samples ranged from 68.6 to 101.4%. For HPLC-MS, solid phase extraction of ground water samples was performed using a polystyrene divinylbenzene polymer resin. The mean HPLC-MS recoveries of the three compounds from ground water samples spiked at 0.05−2 μg/L ranged from 100.9 to 110.3%. The limits of quantitation for HPLC-UV are approximately 150 ng/L for IXF, 100 ng/L for DKN, and 250 ng/L for BA. The limit of quantitation by HPLC-MS is 50 ng/L for each compound. The methods developed in this work can be applied to determine the transport and fate of Balance in the environment.

Ultrasound line-by-line scanning method of spatial-temporal active cavitation mapping for high-intensity focused ultrasound.

PubMed

Ding, Ting; Zhang, Siyuan; Fu, Quanyou; Xu, Zhian; Wan, Mingxi

2014-01-01

This paper presented an ultrasound line-by-line scanning method of spatial-temporal active cavitation mapping applicable in a liquid or liquid filled tissue cavities exposed by high-intensity focused ultrasound (HIFU). Scattered signals from cavitation bubbles were obtained in a scan line immediately after one HIFU exposure, and then there was a waiting time of 2 s long enough to make the liquid back to the original state. As this pattern extended, an image was built up by sequentially measuring a series of such lines. The acquisition of the beamformed radiofrequency (RF) signals for a scan line was synchronized with HIFU exposure. The duration of HIFU exposure, as well as the delay of the interrogating pulse relative to the moment while HIFU was turned off, could vary from microseconds to seconds. The feasibility of this method was demonstrated in tap-water and a tap-water filled cavity in the tissue-mimicking gelatin-agar phantom as capable of observing temporal evolutions of cavitation bubble cloud with temporal resolution of several microseconds, lateral and axial resolution of 0.50 mm and 0.29 mm respectively. The dissolution process of cavitation bubble cloud and spatial distribution affected by cavitation previously generated were also investigated. Although the application is limited by the requirement for a gassy fluid (e.g. tap water, etc.) that allows replenishment of nuclei between HIFU exposures, the technique may be a useful tool in spatial-temporal cavitation mapping for HIFU with high precision and resolution, providing a reference for clinical therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

Determination of isoxaflutole (balance) and its metabolites in water using solid phase extraction followed by high-performance liquid chromatography with ultraviolet or mass spectrometry.

PubMed

Lin, Chung-Ho; Lerch, Robert N; Thurman, E Michael; Garrett, Harold E; George, Milon F

2002-10-09

Balance (isoxaflutole, IXF) belongs to a new family of herbicides referred to as isoxazoles. IXF has a very short soil half-life (<24 h), degrading to a biologically active diketonitrile (DKN) metabolite that is more polar and considerably more stable. Further degradation of the DKN metabolite produces a nonbiologically active benzoic acid (BA) metabolite. Analytical methods using solid phase extraction followed by high-performance liquid chromatography-UV (HPLC-UV) or high-performance liquid chromatography-mass spectrometry (HPLC-MS) were developed for the analysis of IXF and its metabolites in distilled deionized water and ground water samples. To successfully detect and quantify the BA metabolite by HPLC-UV from ground water samples, a sequential elution scheme was necessary. Using HPLC-UV, the mean recoveries from sequential elution of the parent and its two metabolites from fortified ground water samples ranged from 68.6 to 101.4%. For HPLC-MS, solid phase extraction of ground water samples was performed using a polystyrene divinylbenzene polymer resin. The mean HPLC-MS recoveries of the three compounds from ground water samples spiked at 0.05-2 microg/L ranged from 100.9 to 110.3%. The limits of quantitation for HPLC-UV are approximately 150 ng/L for IXF, 100 ng/L for DKN, and 250 ng/L for BA. The limit of quantitation by HPLC-MS is 50 ng/L for each compound. The methods developed in this work can be applied to determine the transport and fate of Balance in the environment.

Discovery of Novel Saponins from the Viscera of the Sea Cucumber Holothuria lessoni

PubMed Central

Bahrami, Yadollah; Zhang, Wei; Franco, Chris

2014-01-01

Sea cucumbers, sometimes referred to as marine ginseng, produce numerous compounds with diverse functions and are potential sources of active ingredients for agricultural, nutraceutical, pharmaceutical and cosmeceutical products. We examined the viscera of an Australian sea cucumber Holothuria lessoni Massin et al. 2009, for novel bioactive compounds, with an emphasis on the triterpene glycosides, saponins. The viscera were extracted with 70% ethanol, and this extract was purified by a liquid-liquid partition process and column chromatography, followed by isobutanol extraction. The isobutanol saponin-enriched mixture was further purified by high performance centrifugal partition chromatography (HPCPC) with high purity and recovery. The resultant purified polar samples were analyzed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)/MS and electrospray ionization mass spectrometry (ESI-MS)/MS to identify saponins and characterize their molecular structures. As a result, at least 39 new saponins were identified in the viscera of H. lessoni with a high structural diversity, and another 36 reported triterpene glycosides, containing different aglycones and sugar moieties. Viscera samples have provided a higher diversity and yield of compounds than observed from the body wall. The high structural diversity and novelty of saponins from H. lessoni with potential functional activities presents a great opportunity to exploit their applications for industrial, agricultural and pharmaceutical use. PMID:24821624

Enzymic cross-linkage of monomeric extensin precursors in vitro. [Lycopersicon esculentum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Everdeen, D.S.; Kiefer, S.; Willard, J.J.

Rapidly growing tomato (Lycopersicon esculentum) cell suspension cultures contain transiently high levels of cell surface, salt-elutable, monomeric precursors to the covalently cross-linked extensin network of the primary cell wall. Thus, the authors purified a highly soluble monomeric extensin substrate from rapidly growing cells, and devised a soluble in vitro cross-linking assay based on Superose-6 fast protein liquid chromatography separation, which resolved extensin monomers from the newly formed oligomers within 25 minutes. Salt elution of slowly growing (early stationary phase) cells yielded little or no extensin monomers but did give a highly active enzymic preparation that specifically cross-linked extensin monomers inmore » the presence of hydrogen peroxide, judging from: (a) a decrease in the extensin monomer peak on fast protein liquid chromatography gel filtration, (b) appearance of oligomeric peaks, and (c) direct electron microscopical observation of the cross-linked oligomers. The cross-linking reaction had a broad pH optimum between 5.5 and 6.5. An approach to substrate saturation of the enzyme required extensin monomer concentrations of 20 to 40 milligrams per milliliter. Preincubation with catalase completely inhibited the cross-linking reaction, which was highly dependent on hydrogen peroxide and optimal at 15 to 50 micromolar. They therefore identified the cross-linking activity as extensin peroxidase.« less

Study of Chromium Oxide Activities in EAF Slags

NASA Astrophysics Data System (ADS)

Yan, Baijun; Li, Fan; Wang, Hui; Sichen, Du

2016-02-01

The activity coefficients of chromium in Cu-Cr melts were determined by equilibrating liquid copper with solid Cr2O3 in CO-CO2 atmosphere. The temperature dependence of the activity coefficients of chromium in Cu-Cr melts could be expressed as lg γ_{Cr}(s)^{0} = { 3 2 5 9( ± 1 8 6} )/T - 0. 5 9( { ± 0. 1} ). Based on the above results, the activities of bivalent and trivalent chromium oxide in some slags at 1873 K (1600 °C) were measured. The slags were equilibrated with Cu-Cr melts under two oxygen partial pressures ( {p_{O}_{ 2} }} } = 6.9 × 10-4 and 1.8 × 10-6 Pa, respectively). The morphology of the quenched slags and the solubility of chromium oxide in the melts were investigated by EPMA, SEM, and XRD. Under both oxygen partial pressures, the slags were saturated by the solid solution MgAl2- x Cr x O4- δ . At the low oxygen partial pressure (1.8 × 10-6 Pa), the content of Cr in the liquid phase varied from 0.4 to 1.6 mass pct with the total Cr content in the slags increasing from 1.3 to 10.8 mass pct. At the high oxygen partial pressure (6.9 × 10-4 Pa), the content of Cr in the liquid phase decreased to the level of 0.2 to 0.6 mass pct. Both the activities of CrO and Cr2O3 in slag were found to increase approximately linearly with the increase of the total Cr content in slag. While the oxygen partial pressure had minor effect on the activity of Cr2O3 in the slag, it had significant effect on the activity of CrO.

Toward comprehensive studies of liquids at high pressures and high temperatures: Combined structure, elastic wave velocity, and viscosity measurements in the Paris-Edinburgh cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kono, Yoshio; Park, Changyong; Kenney-Benson, Curtis

2014-08-19

Techniques for measuring liquid structure, elastic wave velocity, and viscosity under high pressure have been integrated using a Paris–Edinburgh cell at Beamline 16-BM-B, HPCAT of the Advanced Photon Source. The Paris–Edinburgh press allows for compressing large volume samples (up to 2 mm in both diameter and length) up to ~7 GPa and 2000 °C. Multi-angle energy dispersive X-ray diffraction provides structure factors of liquid to a large Q of ~19 Å. Ultrasonic techniques have been developed to investigate elastic wave velocity of liquids combined with the X-ray imaging. Falling sphere viscometry, using high-speed X-ray radiography (>1000 frames/s), enables us tomore » investigate a wide range of viscosity, from those of high viscosity silicates or oxides melts to low viscosity (<1 mPa s) liquids and fluids such as liquid metals or salts. The integration of these multiple techniques has promoted comprehensive studies of structure and physical properties of liquids as well as amorphous materials at high pressures and high temperatures, making it possible to investigate correlations between structure and physical properties of liquids in situ.« less

Performance Tests of a Liquid Hydrogen Propellant Densification Ground System for the X33/RLV

NASA Technical Reports Server (NTRS)

Tomsik, Thomas M.

1997-01-01

A concept for improving the performance of propulsion systems in expendable and single-stage-to-orbit (SSTO) launch vehicles much like the X33/RLV has been identified. The approach is to utilize densified cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants to fuel the propulsion stage. The primary benefit for using this relatively high specific impulse densified propellant mixture is the subsequent reduction of the launch vehicle gross lift-off weight. Production of densified propellants however requires specialized equipment to actively subcool both the liquid oxygen and liquid hydrogen to temperatures below their normal boiling point. A propellant densification unit based on an external thermodynamic vent principle which operates at subatmospheric pressure and supercold temperatures provides a means for the LH2 and LOX densification process to occur. To demonstrate the production concept for the densification of the liquid hydrogen propellant, a system comprised of a multistage gaseous hydrogen compressor, LH2 recirculation pumps and a cryogenic LH2 heat exchanger was designed, built and tested at the NASA Lewis Research Center (LeRC). This paper presents the design configuration of the LH2 propellant densification production hardware, analytical details and results of performance testing conducted with the hydrogen densifier Ground Support Equipment (GSE).

Analysis of capacitive force acting on a cantilever tip at solid/liquid interfaces

NASA Astrophysics Data System (ADS)

Umeda, Ken-ichi; Kobayashi, Kei; Oyabu, Noriaki; Hirata, Yoshiki; Matsushige, Kazumi; Yamada, Hirofumi

2013-04-01

Dielectric properties of biomolecules or biomembranes are directly related to their structures and biological activities. Capacitance force microscopy based on the cantilever deflection detection is a useful scanning probe technique that can map local dielectric constant. Here we report measurements and analysis of the capacitive force acting on a cantilever tip at solid/liquid interfaces induced by application of an alternating voltage to explore the feasibility of the measurements of local dielectric constant by the voltage modulation technique in aqueous solutions. The results presented here suggest that the local dielectric constant measurements by the conventional voltage modulation technique are basically possible even in polar liquid media. However, the cantilever deflection is not only induced by the electrostatic force, but also by the surface stress, which does not include the local dielectric information. Moreover, since the voltage applied between the tip and sample are divided by the electric double layer and the bulk polar liquid, the capacitive force acting on the apex of the tip are strongly attenuated. For these reasons, the lateral resolution in the local dielectric constant measurements is expected to be deteriorated in polar liquid media depending on the magnitude of dielectric response. Finally, we present the criteria for local dielectric constant measurements with a high lateral resolution in polar liquid media.

Apparatus and method for excluding gas from a liquid

DOEpatents

Murphy, Jr., Robert J.

1985-01-01

The present invention is directed to an apparatus and method for preventing diffusion of a gas under high pressure into the bulk of a liquid filling a substantially closed chamber. This apparatus and method is particularly useful in connection with test devices for testing fluid characteristics under harsh conditions of extremely high pressure and high temperature. These devices typically pressurize the liquid by placing the liquid in pressure and fluid communication with a high pressure inert gas. The apparatus and method of the present invention prevent diffusion of the pressurizing gas into the bulk of the test liquid by decreasing the chamber volume at a rate sufficient to maintain the bulk of the liquid free of absorbed or dissolved gas by expelling that portion of the liquid which is contaminated by the pressurizing gas.

Hydrazine-Assisted Liquid Exfoliation of MoS2 for Catalytic Hydrodeoxygenation of 4-Methylphenol.

PubMed

Liu, Guoliang; Ma, Hualong; Teixeira, Ivo; Sun, Zhenyu; Xia, Qineng; Hong, Xinlin; Tsang, Shik Chi Edman

2016-02-24

A simple but effective method to exfoliate bulk MoS2 in a range of solvents is presented for the preparation of colloid flakes consisted of one to a few molecular layers by application of ultrasonic treatment in N2 H4 . Their high yield in solution and exposure of more active surface sites allows the synthesis of corresponding solid catalysts with remarkably high activity in hydrodeoxygenation of 4-methylphenol and this method can also be applied to other two dimensional materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of the in vitro metabolism of TJ0711 using ultra high performance liquid chromatography with quadrupole time-of-flight and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry.

PubMed

Hu, Lei; Lv, Zhenhua; Li, Gao; Xu, Xiaolong; Zhang, Chenghao; Cao, Peng; Huang, Jiangeng; Si, Luqin

2015-06-01

TJ0711 (1-[4-(2-methoxyethyl)phenoxy]-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanol) is a novel β-adrenoreceptor blocker with vasodilating activity. The aim of this study was to investigate the in vitro metabolic properties of TJ0711 from both qualitative and quantitative aspects using mouse, rat, dog, and human liver microsomes as well as rat hepatocytes. Two modern liquid chromatography with tandem mass spectrometry systems, ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry, were utilized for the analysis. To better characterize the metabolic pathways of TJ0711, two major metabolites were incubated under the same conditions as that for TJ0711. TJ0711 was extensively metabolized in vitro, and a total of 34 metabolites, including 19 phase I and 15 phase II metabolites, were identified. Similar metabolite profiles were observed among species, and demethylation, hydroxylation, carboxylic acid formation, and glucuronidation were proposed as the major metabolic routes. Significant interspecies differences were observed in the metabolic stability studies of TJ0711. Furthermore, gender differences were significant in mice, rats, and dogs, but were negligible in humans. The valuable information provided in this work will be useful in planning and interpreting further pharmacokinetic, in vivo metabolism and toxicological studies of this novel β-blocker. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Problems due to superheating of cryogenic liquids

NASA Astrophysics Data System (ADS)

Hands, B. A.

1988-12-01

Superheating can cause several problems in the storage of cryogenic liquids: stratification can cause unexpectedly high tank pressures or, in multicomponent liquids, rollover with its consequential high vaporization rate; geysering causes the rapid expulsion of static liquid from a vertical tube; chugging is a similar phenomenon observed when liquid flows through a reasonably well-insulated pipe.