WorldWideScience

Sample records for ground releases characterization

  1. Section 9: Ground Water - Likelihood of Release

    Science.gov (United States)

    HRS training. the ground water pathway likelihood of release factor category reflects the likelihood that there has been, or will be, a release of hazardous substances in any of the aquifers underlying the site.

  2. Concentration Fluctuations in Smoke Plumes Released Near the Ground

    DEFF Research Database (Denmark)

    Ejsing Jørgensen, Hans; Mikkelsen, Torben; Pécseli, H.L.

    2010-01-01

    Near-ground artificial cloud releases in the turbulent atmospheric boundary layer were investigated experimentally by Lidar measurement techniques. Simple scaling relations between the average concentration and the lowest order moments are suggested by simple analytical models, and the experiment...

  3. SpinSat Mission Ground Truth Characterization

    Science.gov (United States)

    2014-09-01

    SpinSat Mission Ground Truth Characterization Andrew Nicholas, Ted Finne, Ivan Galysh, Anthony Mai, Jim Yen Naval Research Laboratory, Washington...mission overview, ground truth characterization and unique SSA observation opportunities of the mission. 1. MISSION CONCEPT The Naval Research...2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE SpinSat Mission Ground Truth Characterization 5a. CONTRACT

  4. Burial Ground Expansion Hydrogeologic Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Gaughan , T.F.

    1999-02-26

    Sirrine Environmental Consultants provided technical oversight of the installation of eighteen groundwater monitoring wells and six exploratory borings around the location of the Burial Ground Expansion.

  5. Preparation and characterization of slow release formulations of ...

    African Journals Online (AJOL)

    *

    characterize the resulting slow release formulations (SRFs) using scanning electron microscopy. (SEM), and Fourier ... used for controlled release of N-P-K compound fertilizer9 and of ..... fertilizer with controlled release and water retention,.

  6. Concentration Fluctuations in Smoke Plumes Released Near the Ground

    DEFF Research Database (Denmark)

    Ejsing Jørgensen, Hans; Mikkelsen, Torben; Pécseli, H.L.

    2010-01-01

    results are tested against these hypotheses. We find strong evidence for a simple scaling of the standard deviation, skewness and kurtosis with the average concentrations at the downwind distances observed in our experiments. Near-ground concentration fluctuations in fixed as well as moving frames...

  7. Preparation and Characterization of Sustained Release Matrix ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research October 2015; 14(10): 1749-1754 ... prolonged drug release and improvement in motor activity after spinal injuries. Methods: Matrix .... The friability test was performed using a Roche friabilator ...

  8. Characterization of Climax granite ground water

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, D.; Harrar, J.; Raber, E.

    1982-08-01

    The Climax ground water fails to match the commonly held views regarding the nature of deep granitic ground waters. It is neither dilute nor in equilibrium with the granite. Ground-water samples were taken for chemical analysis from five sites in the fractured Climax granite at the Nevada Test Site. The waters are high in total dissolved solids (1200 to 2160 mg/L) and rich in sodium (56 to 250 mg/L), calcium (114 to 283 mg/L) and sulfate (325 to 1060 mg/L). Two of the samples contained relatively high amounts of uranium (1.8 and 18.5 mg/L), whereas the other three contained uranium below the level of detection (< 0.1 mg/L). The pH is in the neutral range (7.3 to 8.2). The differences in composition between samples (as seen in the wide range of values for the major constituents and total dissolved solids) suggest the samples came from different, independent fracture systems. However, the apparent trend of increasing sodium with depth at the expense of calcium and magnesium suggests a common evolutionary chemical process, if not an interconnected system. The waters appear to be less oxidizing with depth (+ 410 mV at 420 m below the surface vs + 86 mV at 565 m). However, with Eh measurements on only two samples, this correlation is questionable. Isotopic analyses show that the waters are of meteoric origin and that the source of the sulfate is probably the pyrite in the fracture-fill material. Analysis of the measured water characteristics using the chemical equilibrium computer program EQ3 indicates that the waters are not in equilibrium with the local mineral assemblage. The solutions appear to be supersaturated with respect to the mineral calcite, quartz, kaolinite, muscovite, k-feldspar, and many others.

  9. Acoustic Characterization of Grass-cover Ground

    Science.gov (United States)

    2014-11-20

    for noise and rever- beration control. Examples of porous media are cements, ceramics, rocks, building insulation , foams and soil. Characterizing the... air is consid- ered as lossless fluid and Eqs. 2.1 and 2.2 can be applied without approximations. However, when acoustic waves travel in narrow...3.1) In Eq. 3.1, P1 and P2 are the acoustic pressures measured at each respective microphone, Pi is the incident pressure, k0 is wave number in air , ω

  10. Novel wound models for characterizing ibuprofen release from foam dressings

    DEFF Research Database (Denmark)

    Steffansen, Bente; Herping, Sofie P K

    2008-01-01

    The purpose of the present study was to design and characterize low exudate level wound (LEW) and high exudate level wound (HEW) in vitro models by means of investigating therapeutic substance release from exudate-absorbing formulations. Biatain Ibu foam dressing was used to characterize in vitro...

  11. Characterization of ground SBR scraps from shoe industry

    OpenAIRE

    Marinês Massarotto; Janaina da Silva Crespo; Ademir José Zattera; Mara Zeni

    2008-01-01

    Expanded poly(butadiene-co-styrene) (SBR), a residue of the shoe industry of Rio Grande do Sul, is a crosslinked material. For further utilization in recycling and reclaiming processes this residue was ground under ambient conditions. The obtained powder (SBR-r) was physically, thermally and chemically characterized and the results were analyzed as for its suitability for reuse methods. This characterization provides a better understanding of the SBR residue components, which may lead to econ...

  12. Hexamethylenetetramine carboxyborane: synthesis, structural characterization and CO releasing properties.

    Science.gov (United States)

    Ayudhya, T I; Raymond, C C; Dingra, N N

    2017-01-17

    Carbon monoxide, although widely known as a toxic gas, has received great attention in the past few decades due to its promising role as a medical gas. Several classes of carbon monoxide releasing molecules (CORMs) have been synthesised with many of them having pharmacological activities under physiological conditions. Herein, we report the synthesis and structural characterization of the first example of amine carboxyborane that releases CO under physiological conditions without the aid of inducers. A representative compound hexamethylenetetramine carboxyborane (HMTA-CB) described here has a half-life of 2.7 days and gradually releases CO with the rate constant of 3.0 × 10(-6) s(-1). Its ability to promote cell growth shows the beneficial effect of slow CO release to supplement CO in small amounts over time.

  13. Polymeric nanoparticles containing diazepam: preparation, optimization, characterization, in-vitro drug release and release kinetic study

    Science.gov (United States)

    Bohrey, Sarvesh; Chourasiya, Vibha; Pandey, Archna

    2016-03-01

    Nanoparticles formulated from biodegradable polymers like poly(lactic-co-glycolic acid) (PLGA) are being extensively investigated as drug delivery systems due to their two important properties such as biocompatibility and controlled drug release characteristics. The aim of this work to formulated diazepam loaded PLGA nanoparticles by using emulsion solvent evaporation technique. Polyvinyl alcohol (PVA) is used as stabilizing agent. Diazepam is a benzodiazepine derivative drug, and widely used as an anticonvulsant in the treatment of various types of epilepsy, insomnia and anxiety. This work investigates the effects of some preparation variables on the size and shape of nanoparticles prepared by emulsion solvent evaporation method. These nanoparticles were characterized by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM). Zeta potential study was also performed to understand the surface charge of nanoparticles. The drug release from drug loaded nanoparticles was studied by dialysis bag method and the in vitro drug release data was also studied by various kinetic models. The results show that sonication time, polymer content, surfactant concentration, ratio of organic to aqueous phase volume, and the amount of drug have an important effect on the size of nanoparticles. Hopefully we produced spherical shape Diazepam loaded PLGA nanoparticles with a size range under 250 nm with zeta potential -23.3 mV. The in vitro drug release analysis shows sustained release of drug from nanoparticles and follow Korsmeyer-Peppas model.

  14. Characterization of Microvesicles Released from Human Red Blood Cells

    Directory of Open Access Journals (Sweden)

    Duc Bach Nguyen

    2016-03-01

    Full Text Available Background/Aims: Extracellular vesicles (EVs are spherical fragments of cell membrane released from various cell types under physiological as well as pathological conditions. Based on their size and origin, EVs are classified as exosome, microvesicles (MVs and apoptotic bodies. Recently, the release of MVs from human red blood cells (RBCs under different conditions has been reported. MVs are released by outward budding and fission of the plasma membrane. However, the outward budding process itself, the release of MVs and the physical properties of these MVs have not been well investigated. The aim of this study is to investigate the formation process, isolation and characterization of MVs released from RBCs under conditions of stimulating Ca2+ uptake and activation of protein kinase C. Methods: Experiments were performed based on single cell fluorescence imaging, fluorescence activated cell sorter/flow cytometer (FACS, scanning electron microscopy (SEM, atomic force microscopy (AFM and dynamic light scattering (DLS. The released MVs were collected by differential centrifugation and characterized in both their size and zeta potential. Results: Treatment of RBCs with 4-bromo-A23187 (positive control, lysophosphatidic acid (LPA, or phorbol-12 myristate-13 acetate (PMA in the presence of 2 mM extracellular Ca2+ led to an alteration of cell volume and cell morphology. In stimulated RBCs, exposure of phosphatidylserine (PS and formation of MVs were observed by using annexin V-FITC. The shedding of MVs was also observed in the case of PMA treatment in the absence of Ca2+, especially under the transmitted bright field illumination. By using SEM, AFM and DLS the morphology and size of stimulated RBCs, MVs were characterized. The sizes of the two populations of MVs were 205.8 ± 51.4 nm and 125.6 ± 31.4 nm, respectively. Adhesion of stimulated RBCs and MVs was observed. The zeta potential of MVs was determined in the range from - 40 mV to - 10 m

  15. Characterization of ground SBR scraps from shoe industry

    Directory of Open Access Journals (Sweden)

    Marinês Massarotto

    2008-03-01

    Full Text Available Expanded poly(butadiene-co-styrene (SBR, a residue of the shoe industry of Rio Grande do Sul, is a crosslinked material. For further utilization in recycling and reclaiming processes this residue was ground under ambient conditions. The obtained powder (SBR-r was physically, thermally and chemically characterized and the results were analyzed as for its suitability for reuse methods. This characterization provides a better understanding of the SBR residue components, which may lead to economic and environmental advantages. The SBR-r (3548 mesh is composed by 22.2% of SBR and 77.8% of filler. The elastomeric fraction has 71.4% of crosslinked material. The results demonstrate that SBR can be recycled for use in microcellular composites.

  16. Chitosan Hydrogels for Chondroitin Sulphate Controlled Release: An Analytical Characterization

    Directory of Open Access Journals (Sweden)

    Annalisa Bianchera

    2014-01-01

    Full Text Available This paper provides an analytical characterization of chitosan scaffolds obtained by freeze-gelation toward the uptake and the controlled release of chondroitin sulphate (CS, as cartilage repair agent, under different pH conditions. Scanning electron microscopy (SEM, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR, and liquid chromatography-UV spectrophotometry (LC-UV techniques were exploited to obtain qualitative and quantitative descriptions of polymer and drug behaviour in the biomaterial. As for morphology, SEM analysis allowed the evaluation of scaffold porosity in terms of pore size and distribution both at the surface (Feret diameter 58±19 μm and on the cross section (Feret diameter 106±51 μm. LC and ATR-FTIR evidenced a pH-dependent CS loading and release behaviour, strongly highlighting the role of electrostatic forces on chitosan/chondroitin sulphate interactions.

  17. Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1.

    Science.gov (United States)

    Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

    2015-12-01

    In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by (137)Cesium ((137)Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as (132)Te-(132)I, (131)I, (134)Cs and (137)Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h(-1) per initial (137)Cs deposition of 1000 kBq m(-2), whereas it was 100 μGy h(-1) around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m(-2) for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums ((134)Cs + (137)Cs) around Chernobyl and Fukushima-1, respectively. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  18. Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1

    Science.gov (United States)

    Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

    2015-01-01

    In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by 137Cesium (137Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as 132Te-132I, 131I, 134Cs and 137Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h−1 per initial 137Cs deposition of 1000 kBq m−2, whereas it was 100 μGy h−1 around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m−2 for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums (134Cs + 137Cs) around Chernobyl and Fukushima-1, respectively. PMID:26568603

  19. DORIS Starec ground antenna characterization and impact on positioning

    Science.gov (United States)

    Tourain, C.; Moreaux, G.; Auriol, A.; Saunier, J.

    2016-12-01

    In a geodetic radio frequency observing system the phase center offsets and phase center variations of ground antennae are a fundamental component of mathematical models of the system observables. In this paper we describe work aimed at improving the DORIS Starec ground antenna phase center definition model. Seven antennas were analyzed in the Compact Antenna Test Range (CATR), a dedicated CNES facility. With respect to the manufacturer specified phase center offset, the measured antennae varied between -6 mm and +4 mm due to manufacturing variations. To solve this problem, discussions were held with the manufacturer, leading to an improvement of the manufacturing process. This work results in a reduction in the scatter to ±1 mm. The phase center position has been kept unchanged and associated phase law has been updated and provided to users of the International DORIS Service (IDS). This phase law is applicable to all Starec antennas (before and after manufacturing process consolidation) and is azimuth independent. An error budget taking into account these updated characteristics has been established for the antenna alone: ±2 mm on the horizontal plane and ±3 mm on the up component, maximum error values for antennas named type C (Saunier et al., 2016) produced with consolidated manufacturing process. Finally the impact of this updated characterization on positioning results has been analyzed and shows a scale offset only of the order of +12 mm for the Terrestrial Reference Frame.

  20. GROUND VIBRATIONS LEVEL CHARACTERIZATION THROUGH THE GEOLOGICAL STRENGTH INDEX (GSI

    Directory of Open Access Journals (Sweden)

    Josip Mesec

    2017-01-01

    Full Text Available This paper analyses the results of trial, construction and quarry blasting, carried out in sediment rock deposits, mainly limestone and dolomite, at diff erent locations in the Republic of Croatia. The division of the three test groups was based on the lithology changes and GSI values of the rock units at these locations. The peak particle velocity measurements with 246 recorded events, was conducted during a long period of six years. Based on the results of seismic measurements, the empirical relationships between peak particle velocity and scaled distance were established for each group. In order to establish a useful relationship between peak particle velocity and scaled distance, simple regression analysis was conducted with the Blastware software program from Instantel. The results of this study can be used to characterize ground vibration levels to the environment, through the geological strength index (GSI.

  1. Evaluation of a soil incubation method to characterize nitrogen release patterns of slow- and controlled-release fertilizers.

    Science.gov (United States)

    Medina, L Carolina; Sartain, Jerry B; Obreza, Thomas A; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release patterns of slow-release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35 degreesC increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (lowa>California>Pennsylvania>Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results.

  2. Effects of uranium-mining releases on ground-water quality in the Puerco River Basin, Arizona and New Mexico

    Science.gov (United States)

    Van Metre, Peter C.; Wirt, Laurie; Lopes, T.J.; Ferguson, S.A.

    1997-01-01

    Shallow ground water beneath the Puerco River of Arizona and New Mexico was studied to determine the effects of uranium-mining releases on water quality. Ground-water samples collected from 1989 to 1991 indicate that concentrations of dissolved uranium have decreased. Most samples from the alluvial aquifer downstream from Gallup, New Mexico, met with U.S. Environmental Protection Agency's maximum contaminant levels for gross alpha, gross beta, and radium and the proposed maximum contaminant level for uranium.

  3. Solar Energetic-Particle Release Times in Historic Ground-Level Events

    Science.gov (United States)

    Reames, Donald V.

    2009-11-01

    Ground-level events (GLEs) are large solar energetic-particle events with sufficiently hard spectra for GeV protons to be detected by neutron monitors at ground level. For each of 30 well-observed historic GLEs from four solar cycles, extending back to 1973, I have plotted onset times versus velocity-1 for particles observed on the IMP-7 and 8, ISEE-3, Wind, and GOES spacecraft and by neutron monitors. A linear fit on such a plot for each GLE determines the initial solar particle release (SPR) time, as the intercept, and the magnetic path length traversed, as the slope, of the fitted line. Magnetic path lengths and SPR times are well determined by the fits and cannot be used as adjustable parameters to make particle and photon emission times coincide. SPR times follow the onsets of shock-induced type II radio bursts and the coronal height of the coronal mass ejection (CME)-driven shock at SPR time can be determined for GLEs spanning an interval of solar longitude of ~140 deg. For a given GLE, all particle species and energies diverge from a single SPR point at a given coronal height and footpoint longitude of the field line to the Earth. These heights tend to increase with longitudinal distance away from the source, a pattern expected for shock acceleration. Acceleration for magnetically well-connected large GLEs begins at ~2 solar radii, in contrast to non-GLEs that have been found to be strongly associated with shocks above ~3 solar radii. The higher densities and magnetic field strengths at lower altitudes may be responsible for the acceleration of higher-energy particles in GLEs, while those GLEs that begin above 3R S may compensate by having higher shock speeds. These results support the joint dependence of maximum particle energy on magnetic field strength, injected particle density, and shock speed, all predicted theoretically.

  4. Study of borehole probing methods to improve the ground characterization

    Science.gov (United States)

    Naeimipour, Ali

    Collecting geological information allows for optimizing ground control measures in underground structures. This includes understanding of the joints and discontinuities and rock strength to develop rock mass classifications. An ideal approach to collect such information is through correlating the drilling data from the roofbolters to assess rock strength and void location and properties. The current instrumented roofbolters are capable of providing some information on these properties but not fully developed for accurate ground characterization. To enhance existing systems additional instrumentation and testing was conducted in laboratory and field conditions. However, to define the geology along the boreholes, the use of probing was deemed to be most efficient approach for locating joints and structures in the ground and evaluation of rock strength. Therefore, this research focuses on selection and evaluation of proper borehole probes that can offer a reliable assessment of rock mass structure and rock strength. In particular, attention was paid to borehole televiewer to characterize rock mass structures and joints and development of mechanical rock scratcher for determination of rock strength. Rock bolt boreholes are commonly drilled in the ribs and the roof of underground environments. They are often small (about 1.5 inches) and short (mostly 2-3 meter). Most of them are oriented upward and thus, mostly dry or perhaps wet but not filled with water. No suitable system is available for probing in such conditions to identify the voids/joints and specifically to measure rock strength for evaluation of rock mass and related optimization of ground support design. A preliminary scan of available borehole probes proved that the best options for evaluation of rock structure is through analysis of borehole images, captured by optical televiewers. Laboratory and field trials with showed that these systems can be used to facilitate measurement of the location, frequency and

  5. Size Distributions and Characterization of Native and Ground Samples for Toxicology Studies

    Science.gov (United States)

    McKay, David S.; Cooper, Bonnie L.; Taylor, Larry A.

    2010-01-01

    This slide presentation shows charts and graphs that review the particle size distribution and characterization of natural and ground samples for toxicology studies. There are graphs which show the volume distribution versus the number distribution for natural occurring dust, jet mill ground dust, and ball mill ground dust.

  6. Preliminary microphysical characterization of precipitation at ground over Antarctica coast

    Science.gov (United States)

    Roberto, Nicoletta; Adirosi, Elisa; Montopoli, Mario; Baldini, Luca; Dietrich, Stefano; Porcù, Federico

    2017-04-01

    The primary mass input of the Antarctic ice sheet is snow precipitation which is one of the most direct climatic indicators. Climatic model simulations of precipitations over Antarctica is an important task to assess the variation of ice sheet over long temporal scale. The main source of precipitation information in Antarctica regions derive from satellite observations. However, satellite measurements and products need to be calibrated and validated with observations from ground sensors. In spite of their key role, precipitation measurements at ground are scarce and not appropriate to provide the specific characteristic of precipitation particles that influence the scattering and absorption properties of ice particles. Recently, different stations in Antarctica (Princess Elizabeth, McMurdo, Mario Zucchelli) are equipping observatories for cloud and precipitation observations. The setup of the observatory at the Italian Station, Mario Zucchelli (MZ) plans to integrate the current instrumentation for weather measurements with other instruments specific for precipitation observations, in particular, a 24-GHz vertical pointing radar and a laser disdrometer Parsivel. The synergetic use of the set of instruments allows for characterizing precipitation and studying properties of Antarctic precipitation such as dimension, shapes, fall behavior, density of particles, particles size distribution, particles terminal velocity, reflectivity factor and including some information on their vertical extent. Last November, the OTT Parsivel disdrometer was installed on the roof of a logistic container (at 6 m of height) of the MZ station (Latitude 74° 41' 42" S; Longitude 164° 07' 23E") in the Terranova Bay. The disdrometer measures size and fall velocity of particles, passing through a laser matrix from which the Particle Size Distribution (PSD) is obtained. In addition, some products such as reflectivity factor, snow rate and snow accumulation can be inferred by properly

  7. Compounding of slow-release niacinamide capsules: feasibility and characterization.

    Science.gov (United States)

    Radojkovic, Branko; Milić, Jela; Calija, Bojan

    2012-01-01

    The purpose of this study was to assess the feasibility of extemporaneous compounding of slow-release oral dosage form of niacinamide and to evaluate its release kinetics. The model formulation (preparation) was developed in the form of powder-filled hard gelatin capsules. Two slow-release preparations with different ratios of hypromellose have been prepared and evaluated in comparison with an immediate-release preparation. The dissolution tests were performed as per United States Pharmacopoeia requirements: Type I Apparatus, over 7 hours. Both slow-release preparations, containing 40% and 60% v/v hypromellose, respectively, have showed slow release kinetics. The dissolution profiles were significantly different, with similarity factor f2niacinamide capsules can be successfully compounded using hypromellose as a sole release rate modifier, and that the release mechanism is comparable to hydrophilic polymer matrix-based systems.

  8. Ground water recharge and flow characterization using multiple isotopes.

    Science.gov (United States)

    Chowdhury, Ali H; Uliana, Matthew; Wade, Shirley

    2008-01-01

    Stable isotopes of delta(18)O, delta(2)H, and (13)C, radiogenic isotopes of (14)C and (3)H, and ground water chemical compositions were used to distinguish ground water, recharge areas, and possible recharge processes in an arid zone, fault-bounded alluvial aquifer. Recharge mainly occurs through exposed stream channel beds as opposed to subsurface inflow along mountain fronts. This recharge distribution pattern may also occur in other fault-bounded aquifers, with important implications for conceptualization of ground water flow systems, development of ground water models, and ground water resource management. Ground water along the mountain front near the basin margins contains low delta(18)O, (14)C (percent modern carbon [pmC]), and (3)H (tritium units [TU]), suggesting older recharge. In addition, water levels lie at greater depths, and basin-bounding faults that locally act as a flow barrier may further reduce subsurface inflow into the aquifer along the mountain front. Chemical differences in ground water composition, attributed to varying aquifer mineralogy and recharge processes, further discriminate the basin-margin and the basin-center water. Direct recharge through the indurated sandstones and mudstones in the basin center is minimal. Modern recharge in the aquifer is mainly through the broad, exposed stream channel beds containing coarse sand and gravel where ground water contains higher delta(18)O, (14)C (pmC), and (3)H (TU). Spatial differences in delta(18)O, (14)C (pmC), and (3)H (TU) and occurrences of extensive mudstones in the basin center suggest sluggish ground water movement, including local compartmentalization of the flow system.

  9. Characterization of the Aerodynamic Ground Effect and Its Influence in Multirotor Control

    Directory of Open Access Journals (Sweden)

    Pedro Sanchez-Cuevas

    2017-01-01

    Full Text Available This paper analyzes the ground effect in multirotors, that is, the change in the thrust generated by the rotors when flying close to the ground due to the interaction of the rotor airflow with the ground surface. This effect is well known in single-rotor helicopters but has been assumed erroneously to be similar for multirotors in many cases in the literature. In this paper, the ground effect for multirotors is characterized with experimental tests in several cases and the partial ground effect, a situation in which one or some of the rotors of the multirotor (but not all are under the ground effect, is also characterized. The influence of the different cases of ground effect in multirotor control is then studied with several control approaches in simulation and validated with experiments in a test bench and with outdoor flights.

  10. Preparation and characterization of metoprolol controlled-release solid dispersions.

    Science.gov (United States)

    Varshosaz, Jaleh; Faghihian, Hossein; Rastgoo, Kobra

    2006-01-01

    In recent years, great attention has been paid to using solid dispersions to make sustained-release drugs. The objective of this study is to produce sustained-release systems of metoprolol tartrate using solid dispersion techniques and to evaluate their physicochemical characteristics. The solid dispersions were produced by melting and solvent methods, containing 7%, 15%, or 25% of the drug and different ratios of Eudragit RLPO and RSPO in ratios of 0:10, 3:7, 5:5, 7:3, and 10:0. Drug release profiles were determined by USP XXIII rotating paddle method in phosphate buffer solution (pH 6.8). XRD, DSC, IR, and microscopic observations were performed to evaluate the physical characteristics of solid dispersions. Results showed that the drug release from dispersions was at a slower rate than pure drug and physical mixtures. Moreover, the formulations containing greater ratios of Eudragit RSPO showed slower release rates and smaller DE8% but larger mean dissolution time than those containing greater ratios of Eudragit RLPO. Dispersions with particle size of less than 100 microm containing 7% of metoprolol and Eudragit RL:RS 5:5 (solvent method) and those with the ratio of 3:7 (melting method) had similar release pattern to Lopressor sustained-release tablets by zero-order and Higuchi kinetics, respectively.

  11. Design and characterization of controlled release tablet of metoprolol

    Directory of Open Access Journals (Sweden)

    Gautam Singhvi

    2012-01-01

    Full Text Available Metoprolol succinate is a selective beta-adrenergic receptor blocker useful in treatment of hypertension, angina and heart failure. The purpose of the present work was to design and evaluate controlled release matrix type tablet of Metoprolo succinate using HPMC K15M and Eudragit (RLPO and RSPO as a matrix forming agents. Effect of various polymer alone and combinations were studied in pH 1.2 buffer using USP type II paddle at 50 rpm. HPMC was used to form firm gel with Eudragit polymer. Formulation with Equal proportion (1:1 of Eudragit RSPO and RLPO showed optimum drug release t50 =7 hrs and t100 =16 hrs indicate optimum permeability for drug release from matrix. The drug release mechanism was predominantly found to be Non-Fickian diffusion controlled.

  12. High Resolution Geological Site Characterization Utilizing Ground Motion Data

    Science.gov (United States)

    1992-06-26

    of the Loma Prieta earthquake. haracicri/aion demonstrate the need for the separation of stochastic and The results of our small field experiments...Array studies of ground Aki, K.. and P. Richards, Quantitative Seismology. Theory and Methods, motions using aftershocks from the Loma Prieta ...Zone with Complete Seismograms is by Bogaards and Stump. This work documents the separation of stochastic and deterministic wave propagation effects in

  13. Novel Caffeic Acid Nanocarrier: Production, Characterization, and Release Modeling

    Directory of Open Access Journals (Sweden)

    Milad Fathi

    2013-01-01

    Full Text Available This paper deals with the development of novel nanocarriers using layer by layer carbohydrate coating of caffeic acid loaded solid lipid nanoparticles (SLNs to improve stability and colon delivery of the poorly water-soluble caffeic acid. Three biopolymers (chitosan, alginate, and pectin in different concentrations (0.1, 0.25, and 0.5% were electrostatically coated over the SLN surface. The size and zeta potential of produced nanocarriers were measured using photon correlation spectroscopy. Mathematical models (i.e., zero-order, first-order, Higuchi, Ritger-Peppas, reciprocal powered time, Weibull, and quadratic models were used to describe the release and kinetic modeling in gastrointestinal solution (GIS. Also, antioxidant activity of caffeic acid during the release in GIS was investigated using DPPH and reducing activity methods. The prepared treatments coated by alginate-chitosan as well as pectin-chitosan coated SLN at the concentration of 0.1% showed nanosized bead; the latter efficiently retarded the release of caffeic acid in gastric media up to 2.5 times higher than that of SLN. Zeta potential values of coated samples were found to significantly increase in comparison to SLN indicating the higher stability of produced nanocarriers. Antioxidant activity of caffeic acid after gastric release did not result in the same trend as observed for caffeic acid release from different treatments; however, in line with less caffeic acid release in the intestine solution by the effect of coating, lower antioxidant activity was determined at the end stage of the experiment.

  14. Synthesis and characterization of novel polypropylene paper releasing anlon

    Institute of Scientific and Technical Information of China (English)

    Li Qiu Wang; Qing Shan Li; Hui Peng Ma; Xiao Feng Guo; Rui Hong Wang; Gang Yao

    2009-01-01

    Polypropylene synthetic paper releasing anion was prepared from polypropylene resin,anion additives,titanium dioxide,etc.,by calendar forming method.The synthetic paper was tested by anion detector,SEM,AFM,etc.Tensile strength,elongation at break,right angle tear strength of the polypropylene synthetic paper reached the GB 13022 or QB,1r/T130 Standard.The synthetic paper was water and oil resistance.and released anions 10,530 cm-3.It Was environment-fendy.and a kind of good material for human'S health.

  15. Site Characterization of Ethanol-Blended Fuel Releases

    Science.gov (United States)

    There has been an increasing use of biofuels (ethanol in particular) in the fuel supply nationwide, and an increase in the number of stations that sell gasoline that contains more than 10% ethanol. The U.S. EPA needs to understand the fate of these materials if they are released ...

  16. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Glynn, P.D.; Voss, C.I. [US Geological Survey, Reston, VA (United States)

    1999-09-01

    The present report analyzes the geochemical data in order to evaluate collection and interpretation techniques that will be used to site the repository and to assess its safety. Ground waters near the Aespoe Hard Rock Laboratory (HRL) may be grouped into five chemically and isotopically distinct water types, on the basis of their deuterium and chloride contents: 1) recent waters, 2) 5 g/L chloride waters, 3) deep waters, 4) seawater imprint waters, and 5) glacial melt waters. The sampled ground waters show a progressive change from a predominantly NaHCO{sub 3} composition at shallow depth to a CaCl{sub 2}-rich composition at depth. Despite the proximity of the Baltic, relatively few of the sampled ground waters contain any evidence of a seawater component. This finding, together with the rather shallow depths at which saline waters were found, indicates that Aespoe island is presently in a regional ground-water discharge area. The chemical and isotopic composition of the sampled waters also indicates that local recharge of dilute recent waters occurs only down to shallow depths (generally less than 100 in). The Aespoe ground waters are sulfidic and do not presently contain any dissolved oxygen. Measured E{sub H} values are generally near -300 mV, and on average are only about 50 mV lower than E{sub H} values calculated from the sulfide/sulfate couple. Maintenance of reducing conditions, such as presently found at the Aespoe HRL, is an important consideration in assessing the performance of nuclear waste disposal sites. Measurements of dissolved radon and of uranium concentrations in fracture-fill materials were used to calculate an average effective flow-wetted surface area of 3.1 m{sup 2} per liter of water for the Aespoe site. Estimation of flow-wetted surface areas is essential in determining the importance of matrix diffusion and surface sorption processes for radionuclide release calculations. The Rn calculation technique shows promise in helping narrow the

  17. Rock characterization while drilling and application of roof bolter drilling data for evaluation of ground conditions

    Institute of Scientific and Technical Information of China (English)

    Jamal Rostami; Sair Kahraman; Ali Naeimipour; Craig Collins

    2015-01-01

    Despite recent advances in mine health and safety, roof collapse and instabilities are still the leading causes of injury and fatality in underground mining operations. Improving safety and optimum design of ground support requires good and reliable ground characterization. While many geophysical methods have been developed for ground characterizations, their accuracy is insufficient for customized ground support design of underground workings. The actual measurements on the samples of the roof and wall strata from the exploration boring are reliable but the related holes are far apart, thus unsuitable for design purposes. The best source of information could be the geological back mapping of the roof and walls, but this is disruptive to mining operations, and provided information is only from rock surface. Interpretation of the data obtained from roof bolt drilling can offer a good and reliable source of in-formation that can be used for ground characterization and ground support design and evaluations. This paper offers a brief review of the mine roof characterization methods, followed by introduction and discussion of the roof characterization methods by instrumented roof bolters. A brief overview of the results of the preliminary study and initial testing on an instrumented drill and summary of the sug-gested improvements are also discussed.

  18. Rock characterization while drilling and application of roof bolter drilling data for evaluation of ground conditions

    Directory of Open Access Journals (Sweden)

    Jamal Rostami

    2015-06-01

    Full Text Available Despite recent advances in mine health and safety, roof collapse and instabilities are still the leading causes of injury and fatality in underground mining operations. Improving safety and optimum design of ground support requires good and reliable ground characterization. While many geophysical methods have been developed for ground characterizations, their accuracy is insufficient for customized ground support design of underground workings. The actual measurements on the samples of the roof and wall strata from the exploration boring are reliable but the related holes are far apart, thus unsuitable for design purposes. The best source of information could be the geological back mapping of the roof and walls, but this is disruptive to mining operations, and provided information is only from rock surface. Interpretation of the data obtained from roof bolt drilling can offer a good and reliable source of information that can be used for ground characterization and ground support design and evaluations. This paper offers a brief review of the mine roof characterization methods, followed by introduction and discussion of the roof characterization methods by instrumented roof bolters. A brief overview of the results of the preliminary study and initial testing on an instrumented drill and summary of the suggested improvements are also discussed.

  19. IN-VITRO RELEASE CHARACTERIZATION OF KETOROLAC TROMETHAMINE LOADED MATRIX TABLETS

    Directory of Open Access Journals (Sweden)

    Sayed Koushik Ahamed, Sujan Banik and Mohammad Salim Hossain*

    2013-03-01

    Full Text Available ABSTRACT: The present investigation highlighted the formulation and release characterization of Ketorolac Tromethamine loaded matrix tablet. Various formulations of tablets were prepared by direct compression method along with Kollidon SR and Hydroxy Propyl Methyl Cellulose (HPMC as release retardant polymers. Each of the formulated tablets contains 50mg Ketorolac Tromethamine. The evaluation involved physical properties studies (weight variation, thickness, length, width, hardness, friability, and drug content of tablets and in vitro release kinetics assessment. The USP paddle method was operated at 50 rpm selected to perform the dissolution test and 900 ml phosphate buffer of pH 7.4 was used as dissolution medium. The drug release from each formulation was analyzed by using release kinetics theories. All formulations followed Higuchi release kinetics. When the release data was plotted into Korsemeyer-Peppas equation, then it was confirmed that F-1 to F-5 exhibited fickian type drug release whereas F-6 exhibited non-Fickian type drug release. The in-vitro release studies revealed that the formulation F-4 can be taken as an ideal or optimized formulation of sustained release tablets. Furthermore, the dissolution of the formulation-4 was performed in SLS (1%, 1.5%, and 2% medium, which was observed gradually decreasing release rate as concentration of SLS medium increased.

  20. TARDEC Ground Vehicle Robotics: Vehicle Dynamic Characterization and Research

    Science.gov (United States)

    2015-09-01

    reason why most consumer automobiles come from the factory in an understeer configuration, so that if something goes wrong in a maneuver, the car will...This has a bit to do with suspension design, which isn’t something I want to dive into, so I’ll keep the explanations brief and google can fill... car loses traction and skids out. This test is essential in characterizing the UNCLASSIFIED UNCLASSIFIED steady state cornering capabilities of

  1. Characterization of ground state entanglement by single-qubit operations and excitation energies

    CERN Document Server

    Giampaolo, S M; Illuminati, F; Verrucchi, P; Giampaolo, Salvatore M.; Illuminati, Fabrizio; Siena, Silvio De; Verrucchi, Paola

    2006-01-01

    We consider single-qubit unitary operations and study the associated excitation energies above the ground state of interacting quantum spins. We prove that there exists a unique operation such that the vanishing of the corresponding excitation energy determines a necessary and sufficient condition for the separability of the ground state. We show that the energy difference associated to factorization exhibits a monotonic behavior with the one-tangle and the entropy of entanglement, including non analiticity at quantum critical points. The single-qubit excitation energy thus provides an independent, directly observable characterization of ground state entanglement, and a simple relation connecting two universal physical resources, energy and nonlocal quantum correlations.

  2. Characterization and nutrient release from silicate rocks and influence on chemical changes in soil

    Directory of Open Access Journals (Sweden)

    Douglas Ramos Guelfi Silva

    2012-06-01

    Full Text Available The expansion of Brazilian agriculture has led to a heavy dependence on imported fertilizers to ensure the supply of the growing food demand. This fact has contributed to a growing interest in alternative nutrient sources, such as ground silicate rocks. It is necessary, however, to know the potential of nutrient release and changes these materials can cause in soils. The purpose of this study was to characterize six silicate rocks and evaluate their effects on the chemical properties of treated soil, assessed by chemical extractants after greenhouse incubation. The experimental design consisted of completely randomized plots, in a 3 x 6 factorial scheme, with four replications. The factors were potassium levels (0-control: without silicate rock application; 200; 400; 600 kg ha-1 of K2O, supplied as six silicate rock types (breccia, biotite schist, ultramafic rock, phlogopite schist and two types of mining waste. The chemical, physical and mineralogical properties of the alternative rock fertilizers were characterized. Treatments were applied to a dystrophic Red-Yellow Oxisol (Ferralsol, which was incubated for 100 days, at 70 % (w/w moisture in 3.7 kg/pots. The soil was evaluated for pH; calcium and magnesium were extracted with KCl 1 mol L-1; potassium, phosphorus and sodium by Mehlich 1; nickel, copper and zinc with DTPA; and the saturation of the cation exchange capacity was calculated for aluminum, calcium, magnesium, potassium, and sodium, and overall base saturation. The alternative fertilizers affected soil chemical properties. Ultramafic rock and Chapada mining byproduct (CMB were the silicate rocks that most influenced soil pH, while the mining byproduct (MB led to high K levels. Zinc availability was highest in the treatments with mining byproduct and Cu in soil fertilized with Chapada and mining byproduct.

  3. Characterization of subarctic vegetation using ground based remote sensing methods

    Science.gov (United States)

    Finnell, D.; Garnello, A.; Palace, M. W.; Sullivan, F.; Herrick, C.; Anderson, S. M.; Crill, P. M.; Varner, R. K.

    2014-12-01

    Stordalen mire is located at 68°21'N and 19°02'E in the Swedish subarctic. Climate monitoring has revealed a warming trend spanning the past 150 years affecting the mires ability to hold stable palsa/hummock mounds. The micro-topography of the landscape has begun to degrade into thaw ponds changing the vegetation cover from ombrothrophic to minerotrophic. Hummocks are ecologically important due to their ability to act as a carbon sinks. Thaw ponds and sphagnum rich transitional zones have been documented as sources of atmospheric CH4. An objective of this project is to determine if a high resolution three band camera (RGB) and a RGNIR camera could detect differences in vegetation over five different site types. Species composition was collected for 50 plots with ten repetitions for each site type: palsa/hummock, tall shrub, semi-wet, tall graminoid, and wet. Sites were differentiated based on dominating species and features consisting of open water presence, sphagnum spp. cover, graminoid spp. cover, or the presence of dry raised plateaus/mounds. A pole based camera mount was used to collect images at a height of ~2.44m from the ground. The images were cropped in post-processing to fit a one-square meter quadrat. Texture analysis was performed on all images, including entropy, lacunarity, and angular second momentum. Preliminary results suggested that site type influences the number of species present. The p-values for the ability to predict site type using a t-test range from <0.0001 to 0.0461. A stepwise discriminant analysis on site type vs. texture yielded a 10% misclassification rate. Through the use of a stepwise regression of texture variables, actual vs. predicted percent of vegetation coverage provided R squared values of 0.73, 0.71, 0.67, and 0.89 for C. bigelowii, R. chamaemorus, Sphagnum spp., and open water respectively. These data have provided some support to the notion that texture analyses can be used for classification of mire site types. Future

  4. Ground Penetrating Radar technique for railway track characterization in Portugal

    Science.gov (United States)

    De Chiara, Francesca; Fontul, Simona; Fortunato, Eduardo; D'Andrea, Antonio

    2013-04-01

    Maintenance actions are significant for transport infrastructures but, today, costs have to be necessary limited. A proper quality control since the construction phase is a key factor for a long life cycle and for a good economy policy. For this reason, suitable techniques have to be chosen and non-destructive tests represent an efficient solution, as they allow to evaluate infrastructure characteristics in a continuous or quasi-continuous way, saving time and costs, enabling to make changes if tests results do not comply with the project requirements. Ground Penetrating Radar (GPR) is a quick and effective technique to evaluate infrastructure condition in a continuous manner, replacing or reducing the use of traditional drilling method. GPR application to railways infrastructures, during construction and monitoring phase, is relatively recent. It is based on the measuring of layers thicknesses and detection of structural changes. It also enables the assessment of materials properties that constitute the infrastructure and the evaluation of the different types of defects such as ballast pockets, fouled ballast, poor drainage, subgrade settlement and transitions problems. These deteriorations are generally the causes of vertical deviations in track geometry and they cannot be detected by the common monitoring procedures, namely the measurements of track geometry. Moreover, the development of new GPR systems with higher antenna frequencies, better data acquisition systems, more user friendly software and new algorithms for calculation of materials properties can lead to a regular use of GPR. Therefore, it represents a reliable technique to assess track geometry problems and consequently to improve maintenance planning. In Portugal, rail inspection is performed with Plasser & Theurer EM120 equipment and recently 400 MHz IDS antennas were installed on it. GPR tests were performed on the Portuguese rail network and, as case study in this paper, a renewed track was

  5. Preparation and characterization of controlled release matrices based on novel seaweed interpolyelectrolyte complexes.

    Science.gov (United States)

    Prado, Héctor J; Matulewicz, María C; Bonelli, Pablo R; Cukierman, Ana L

    2012-06-15

    Novel interpolyelectrolyte complexes (IPECs) between naturally sulfated polysaccharides of the seaweed Polysiphonia nigrescens (PN) and cationized agaroses (CAG) and Eudragit E (EE) were prepared using an organic solvent free process, characterized, and explored for controlled drug release. Tablets containing model drug ibuprofen and IPECs were prepared by direct compression. Drug release in acid medium was low owing to the low solubility of ibuprofen in that condition and to the matrix action. Zero order drug release was determined in the buffer stage (pH=6.8), with Fickian diffusion predominating over relaxation during the initial phases. Relaxation appears to increase along the release process and even overcomes diffusion for some systems. Drug release profiles could be controlled by varying the content of IPECs in the tablets. Also, the change in molecular weight and the degree of substitution of the components allowed altering the release profiles.

  6. Characterization of an In-Situ Ground Terminal via a Geostationary Satellite

    Science.gov (United States)

    Piasecki, Marie; Welch, Bryan; Mueller, Carl

    2015-01-01

    In 2015, the Space Communications and Navigation (SCaN) Testbed project completed an S-Band ground station located at the NASA Glenn Research Center in Cleveland, Ohio. This S-Band ground station was developed to create a fully characterized and controllable dynamic link environment when testing novel communication techniques for Software Defined Radios and Cognitive Communication Systems. In order to provide a useful environment for potential experimenters, it was necessary to characterize various RF devices at both the component level in the laboratory and at the system level after integration. This paper will discuss some of the laboratory testing of the ground station components, with a particular focus emphasis on the near-field measurements of the antenna. It will then describe the methodology for characterizing the installed ground station at the system level via a Tracking and Data Relay Satellite (TDRS), with specific focus given to the characterization of the ground station antenna pattern, where the max TDRS transmit power limited the validity of the non-noise floor received power data to the antenna main lobe region. Finally, the paper compares the results of each test as well as provides lessons learned from this type of testing methodology.

  7. Use of Electrical Conductivity Logging to Characterize the Geological Context of Releases at UST Sites

    Science.gov (United States)

    Risk is the combination of hazard and exposure. Risk characterization at UST release sites has traditionally emphasized hazard (presence of residual fuel) with little attention to exposure. Exposure characterization often limited to a one-dimensional model such as the RBCA equa...

  8. Impact of ground motion characterization on conservatism and variability in seismic risk estimates

    Energy Technology Data Exchange (ETDEWEB)

    Sewell, R.T.; Toro, G.R.; McGuire, R.K.

    1996-07-01

    This study evaluates the impact, on estimates of seismic risk and its uncertainty, of alternative methods in treatment and characterization of earthquake ground motions. The objective of this study is to delineate specific procedures and characterizations that may lead to less biased and more precise seismic risk results. This report focuses on sources of conservatism and variability in risk that may be introduced through the analytical processes and ground-motion descriptions which are commonly implemented at the interface of seismic hazard and fragility assessments. In particular, implication of the common practice of using a single, composite spectral shape to characterize motions of different magnitudes is investigated. Also, the impact of parameterization of ground motion on fragility and hazard assessments is shown. Examination of these results demonstrates the following. (1) There exists significant conservatism in the review spectra (usually, spectra characteristic of western U.S. earthquakes) that have been used in conducting past seismic risk assessments and seismic margin assessments for eastern U.S. nuclear power plants. (2) There is a strong dependence of seismic fragility on earthquake magnitude when PGA is used as the ground-motion characterization. When, however, magnitude-dependent spectra are anchored to a common measure of elastic spectral acceleration averaged over the appropriate frequency range, seismic fragility shows no important nor consistent dependence on either magnitude or strong-motion duration. Use of inelastic spectral acceleration (at the proper frequency) as the ground spectrum anchor demonstrates a very similar result. This study concludes that a single, composite-magnitude spectrum can generally be used to characterize ground motion for fragility assessment without introducing significant bias or uncertainty in seismic risk estimates.

  9. Development and In Vitro Characterization of Sustained Release Pellets of Venlafaxine Hydrochloride

    OpenAIRE

    P.REMYA; N. Damodharan; Dinesh Kumar, S.; V. Sowjanya

    2012-01-01

    The present study was undertaken with development and in-vitro characterization of sustained release pellets of venlafaxine hydrochloride by wruster process technique .which release the drug in sustained manner over a period of 20 hours. The different viscosity grades of polymers are HPMC-E6, Ethyl cellulose 7cps, MCC-101 were preparation of granules or pellets by wurster coating .The granules were prepared and evaluated for Angle of repose, bulk density, tapped density, cars index, moisture ...

  10. Uncertainty characterization in the retrieval of an atmospheric point release

    Science.gov (United States)

    Singh, Sarvesh Kumar; Kumar, Pramod; Turbelin, Grégory; Rani, Raj

    2017-03-01

    The study proposes a methodology in a recent inversion technique, called as Renormalization, to characterize the uncertainties in the reconstruction of a point source. The estimates are derived for measuring the inversion error, the degree of model fit towards measurements (model determination coefficient) and the confidence intervals for the retrieved point source parameters (mainly, location and strength). The inversion error is reflected through an angular estimate which measures the deviation between the measured and predicted concentrations. The uncertainty estimation methodology is evaluated for point source reconstruction studies, using real measurements from two field experiments, known as Fusion Field Trials 2007 (FFT07) in flat terrain and Mock Urban Setting Test (MUST) in urban like terrain. In FFT07 and MUST experiments, the point source location is retrieved with an average Euclidean distance of 22 m and 15 m respectively. The source strength is retrieved, on average, within a factor of 1.5 in both the datasets. The inversion error is observed as 24o and 21o in FFT07 and MUST experiment, respectively. The 95% confidence interval estimates show that the uncertainty in the retrieved parameters is relatively large in approximately 50% FFT07 and 30% MUST trials in spite of their closeness towards true source parameters. For a comparative analysis, the interval estimates are also compared with a more general method of uncertainty estimation, Residual Bootstrap Sampling. In most of the trials, we observed that the intervals estimates with the present method are comparable (within 10-20% variations) to bootstrap estimates. The proposed methodology provides near accurate and computationally efficient uncertainty estimates in comparison to the methods based on Hessian and sampling procedures.

  11. Nursing care process for releasing psychiatric inpatients from long-term seclusion in Japan: modified grounded theory approach.

    Science.gov (United States)

    Nagayama, Yutaka; Hasegawa, Masami

    2014-09-01

    Based on a modified grounded theory approach, in this study, we sought to elucidate the nursing care process used to guide psychiatric inpatients in long-term seclusion towards release from seclusion. Participant observations and interviews were conducted with a total of 18 nurses from three long-term psychiatric wards at two institutions from September 2011 to November 2012, to collect data on the nursing care they provided for psychiatric patients in long-term seclusion. Consequently, four categories and 15 concepts were extracted. The nurses viewed "a mature therapeutic environment that utilizes flexible apportionment of care" as the foundation (i.e. the core category) in guiding psychiatric inpatients towards release from long-term seclusion. The results revealed a care structure in which nurses in such a treatment environment provided care by flexible apportionment of three types of care: care aimed at avoiding mental and physical exhaustion, standardized care that does not confer a disadvantage to patients, and immediately responding to prevent problematic behaviors.

  12. Review of Ground Characterization by Using Instrumented Drills for Underground Mining and Construction

    Science.gov (United States)

    Kahraman, Sair; Rostami, Jamal; Naeimipour, Ali

    2016-02-01

    In underground mining, many miners are injured or lose their lives because of roof/pillar instability each year, and this is a persistent safety risk. Characterization of overlying strata is important for the design of safe and cost-effective ground support systems. Entry roof characterization can be performed by geological back-mapping of the ground using various methods such as geophysical logging, borescoping, rock mass rating, and intelligent roof bolt drilling systems. This paper offers a brief review of mine roof characterization methods, followed by an introduction to and discussion of roof characterization methods using instrumented roof bolters. A brief overview of the various instrumentation systems developed for roof bolt drills is presented. The results of the preliminary study and initial testing indicate that, despite recent improvements in the area of ground characterization by instrumented drills, there are still several issues that must be addressed to improve the efficiency and accuracy of existing systems. A summary of suggested improvements is provided.

  13. Identification of active release planes using ground-based differential InSAR at the Randa rock slope instability, Switzerland

    Directory of Open Access Journals (Sweden)

    V. Gischig

    2009-12-01

    Full Text Available Five ground-based differential interferometric synthetic aperture radar (GB-DInSAR surveys were conducted between 2005 and 2007 at the rock slope instability at Randa, Switzerland. Resultant displacement maps revealed, for the first time, the presence of an active basal rupture zone and a lateral release surface daylighting on the exposed 1991 failure scarp. Structures correlated with the boundaries of interferometric displacement domains were confirmed using a helicopter-based LiDAR DTM and oblique aerial photography. Former investigations at the site failed to conclusively detect these active release surfaces essential for kinematic and hazard analysis of the instability, although their existence had been hypothesized. The determination of the basal and lateral release planes also allowed a more accurate estimate of the currently unstable volume of 5.7±1.5 million m3. The displacement patterns reveal that two different kinematic behaviors dominate the instability, i.e. toppling above 2200 m and translational failure below. In the toppling part of the instability the areas with the highest GB-DInSAR displacements correspond to areas of enhanced micro-seismic activity. The observation of only few strongly active discontinuities daylighting on the 1991 failure surface points to a rather uniform movement in the lower portion of the instability, while most of the slip occurs along the basal rupture plane. Comparison of GB-DInSAR displacements with mapped discontinuities revealed correlations between displacement patterns and active structures, although spatial offsets occur as a result of the effective resolution of GB-DInSAR. Similarly, comparisons with measurements from total station surveys generally showed good agreement. Discrepancies arose in several cases due to local movement of blocks, the size of which could not be resolved using GB-DInSAR.

  14. Earth-Facing Antenna Characterization in a Complex Ground Plane/Multipath Rich Environment

    Science.gov (United States)

    Welch, Bryan W.; Piasecki, Marie T.

    2015-01-01

    The Space Communications and Navigation (SCAN) Testbed was a Software Defined Radio (SDR)-based payload launched to the International Space Station (ISS) in July of 2012. The purpose of the SCAN Testbed payload was to investigate the applicability of SDRs to NASA space missions in an operational space environment, which means that a proper model for system performance in said operational space environment is a necessary condition. The SCAN Testbed has line-of-sight connections to various ground stations with its S-Band Earth-facing Near-Earth Network Low Gain Antenna (NEN-LGA). Any previous efforts to characterize the NEN-LGA proved difficult, therefore, the NASA Glenn Research Center built its own S-Band ground station, which became operational in 2015, and has been successfully used to characterize the NEN-LGAs in-situ pattern measurements. This methodology allows for a more realistic characterization of the antenna performance, where the pattern oscillation induced by the complex ISS ground plane, as well as shadowing effects due to ISS structural blockage are included into the final performance model. This paper describes the challenges of characterizing an antenna pattern in this environment. It will also discuss the data processing, present the final antenna pattern measurements and derived model, as well as discuss various lessons learned.

  15. Earth-Facing Antenna Characterization in Complex Ground Plane/Multipath Rich Environment

    Science.gov (United States)

    Welch, Bryan W.; Piasecki, Marie T.

    2015-01-01

    The Space Communications and Navigation (SCAN) Testbed was a Software Defined Radio (SDR)-based payload launched to the International Space Station (ISS) in July of 2012. The purpose of the SCAN Testbed payload was to investigate the applicability of SDRs to NASA space missions in an operational environment, which means that a proper model for system performance in said operational space environment is a necessary condition. The SCAN Testbed has line-of-sight connections to various ground stations with its S-Band Earth-facing Near-Earth-Network Low Gain Antenna (NEN-LGA). Any previous efforts to characterize the NEN-LGA proved difficult, therefore, the NASA Glenn Research Center built its own S-Band ground station, which became operational in 2015, and has been used successfully to characterize the NEN-LGA's in-situ pattern measurements. This methodology allows for a more realistic characterization of the antenna performance, where the pattern oscillation induced by the complex ISS ground plane, as well as shadowing effects due to ISS structural blockage are included into the final performance model. This paper describes the challenges of characterizing an antenna pattern in this environment. It will also discuss the data processing, present the final antenna pattern measurements and derived model, as well as discuss various lessons learned

  16. Characterization of 618-11 solid waste burial ground, disposed waste, and description of the waste generating facilities

    Energy Technology Data Exchange (ETDEWEB)

    Hladek, K.L.

    1997-10-07

    The 618-11 (Wye or 318-11) burial ground received transuranic (TRTJ) and mixed fission solid waste from March 9, 1962, through October 2, 1962. It was then closed for 11 months so additional burial facilities could be added. The burial ground was reopened on September 16, 1963, and continued operating until it was closed permanently on December 31, 1967. The burial ground received wastes from all of the 300 Area radioactive material handling facilities. The purpose of this document is to characterize the 618-11 solid waste burial ground by describing the site, burial practices, the disposed wastes, and the waste generating facilities. This document provides information showing that kilogram quantities of plutonium were disposed to the drum storage units and caissons, making them transuranic (TRU). Also, kilogram quantities of plutonium and other TRU wastes were disposed to the three trenches, which were previously thought to contain non-TRU wastes. The site burial facilities (trenches, caissons, and drum storage units) should be classified as TRU and the site plutonium inventory maintained at five kilograms. Other fissile wastes were also disposed to the site. Additionally, thousands of curies of mixed fission products were also disposed to the trenches, caissons, and drum storage units. Most of the fission products have decayed over several half-lives, and are at more tolerable levels. Of greater concern, because of their release potential, are TRU radionuclides, Pu-238, Pu-240, and Np-237. TRU radionuclides also included slightly enriched 0.95 and 1.25% U-231 from N-Reactor fuel, which add to the fissile content. The 618-11 burial ground is located approximately 100 meters due west of Washington Nuclear Plant No. 2. The burial ground consists of three trenches, approximately 900 feet long, 25 feet deep, and 50 feet wide, running east-west. The trenches constitute 75% of the site area. There are 50 drum storage units (five 55-gallon steel drums welded together

  17. Characterization and optimization of GMO-based gels with long term release for intraarticular administration.

    Science.gov (United States)

    Réeff, J; Gaignaux, A; Goole, J; Siepmann, J; Siepmann, F; Jerome, C; Thomassin, J M; De Vriese, C; Amighi, K

    2013-07-15

    Osteoarthritis is characterized by slow degenerative processes in the articular cartilage within synovial joints. It could be interesting to develop a sustained-release formulation that could be effective on both pain/inflammation and restoration of mechanical integrity of the joint. Recently, an injectable system based on glycerol monooleate (GMO), containing clonidine as a model hydrophilic analgesic/anti-inflammatory drug and hyaluronic acid as a viscoelastic scaffold, showed promising potential as a biodegradable and biocompatible preparation to sustain the drug activity. However, drug release from the system is relatively fast (complete within 1 week) and the underlying drug release mechanisms not fully understood. The aims of this study were: (i) to significantly improve this type of local controlled drug delivery system by further sustaining clonidine release, and (ii) to elucidate the underlying mass transport mechanisms. The addition of FDA-approved inactive ingredients such as sodium oleate or purified soybean oil was found to be highly effective. The release rate could be substantially reduced (e.g., 50% release after 10 days), due to the increased hydrophobicity of the systems, resulting in slower and reduced water uptake and reduced drug mobility. Interestingly, Fick's second law of diffusion could be used to quantitatively describe drug release. Copyright © 2013. Published by Elsevier B.V.

  18. Characterization of Vacuum Facility Background Gas Through Simulation and Considerations for Electric Propulsion Ground Testing

    Science.gov (United States)

    Yim, John T.; Burt, Jonathan M.

    2015-01-01

    The background gas in a vacuum facility for electric propulsion ground testing is examined in detail through a series of cold flow simulations using a direct simulation Monte Carlo (DSMC) code. The focus here is on the background gas itself, its structure and characteristics, rather than assessing its interaction and impact on thruster operation. The background gas, which is often incorrectly characterized as uniform, is found to have a notable velocity within a test facility. The gas velocity has an impact on the proper measurement of pressure and the calculation of ingestion flux to a thruster. There are also considerations for best practices for tests that involve the introduction of supplemental gas flows to artificially increase the background pressure. All of these effects need to be accounted for to properly characterize the operation of electric propulsion thrusters across different ground test vacuum facilities.

  19. Fast-scan Cyclic Voltammetry for the Characterization of Rapid Adenosine Release.

    Science.gov (United States)

    Nguyen, Michael D; Venton, B Jill

    2015-01-01

    Adenosine is a signaling molecule and downstream product of ATP that acts as a neuromodulator. Adenosine regulates physiological processes, such as neurotransmission and blood flow, on a time scale of minutes to hours. Recent developments in electrochemical techniques, including fast-scan cyclic voltammetry (FSCV), have allowed direct detection of adenosine with sub-second temporal resolution. FSCV studies have revealed a novel mode of rapid signaling that lasts only a few seconds. This rapid release of adenosine can be evoked by electrical or mechanical stimulations or it can be observed spontaneously without stimulation. Adenosine signaling on this time scale is activity dependent; however, the mode of release is not fully understood. Rapid adenosine release modulates oxygen levels and evoked dopamine release, indicating that adenosine may have a rapid modulatory role. In this review, we outline how FSCV can be used to detect adenosine release, compare FSCV with other techniques used to measure adenosine, and present an overview of adenosine signaling that has been characterized using FSCV. These studies point to a rapid mode of adenosine modulation, whose mechanism and function will continue to be characterized in the future.

  20. 618-10 Burial Ground Trench Remediation and 618-10 and 618-11 Burial Ground Nonintrusive Characterization of Vertical Pipe Units Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Darby, J. W.

    2012-06-28

    A “lessons learned” is a noteworthy practice or innovative approach that is captured and shared to promote repeat application, or an adverse work practice/experience that is captured and shared to avoid reoccurrence. This document provides the lessons learned identified by the 618-10 Burial Ground trench remediation and the 618-10 and 618-11 Burial Ground nonintrusive characterization of the vertical pipe units (VPUs).

  1. Synthesis and characterization of a HAp-based biomarker with controlled drug release for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    González, Maykel [Dept. of Molecular Engineering of Materials, Center of Applied Physics and Advanced Technology, National Autonomous University of Mexico (CFATA-UNAM), Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro 76230 (Mexico); Merino, Ulises [Dept. of Molecular Engineering of Materials, Center of Applied Physics and Advanced Technology, National Autonomous University of Mexico (CFATA-UNAM), Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro 76230 (Mexico); University of the Valley of Mexico (UVM), Boulevard Villas del Mesón 1000, Juriquilla, Santiago de Querétaro, Querétaro 76320 (Mexico); Vargas, Susana [Dept. of Molecular Engineering of Materials, Center of Applied Physics and Advanced Technology, National Autonomous University of Mexico (CFATA-UNAM), Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro 76230 (Mexico); Quintanilla, Francisco [University of the Valley of Mexico (UVM), Boulevard Villas del Mesón 1000, Juriquilla, Santiago de Querétaro, Querétaro 76320 (Mexico); Rodríguez, Rogelio, E-mail: rogelior@unam.mx [Dept. of Molecular Engineering of Materials, Center of Applied Physics and Advanced Technology, National Autonomous University of Mexico (CFATA-UNAM), Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro 76230 (Mexico)

    2016-04-01

    A biocompatible hybrid porous polymer–ceramic material was synthesized to be used as a biomarker in the treatment of breast cancer. This device was equipped with the capacity to release medicaments locally in a controlled manner. The biomaterial was Hydroxyapatite(HAp)-based and had a controlled pore size and pore volume fraction. It was implemented externally using a sharp end and a pair of barbed rings placed opposite each other to prevent relative movement once implanted. The biomarker was impregnated with cis-diamine dichloride platinum (II) [Cl{sub 2}-Pt-(NH{sub 3}){sub 2}]; the rate of release was obtained using inductively coupled plasma atomic emission spectroscopy (ICP-AES), and release occurred over the course of three months. Different release profiles were obtained as a function of the pore volume fraction. The biomaterial was characterized using scanning electron microscopy (SEM) and Raman spectroscopy. - Highlights: • A novel biocompatible hybrid porous polymer–ceramic material was synthesized. • The polymer–ceramic (HAp-based) material was used to prepare a biomarker. • The biomarker was impregnated with cis-diamine dichloride platinum (II). • The rate of cisplatin release was determined using inductively coupled plasma. • The kinetics of the cisplatin release was studied varying the biomarker porosity.

  2. Preparation and characterization of controlled-release fertilizers coated with marine polysaccharide derivatives

    Science.gov (United States)

    Wang, Jing; Liu, Song; Qin, Yukun; Chen, Xiaolin; Xing, Rong'e.; Yu, Huahua; Li, Kecheng; Li, Pengcheng

    2017-09-01

    Encapsulation of water-soluble nitrogen fertilizers by membranes can be used to control the release of nutrients to maximize the fertilization effect and reduce environmental pollution. In this research, we formulated a new double-coated controlled-release fertilizer (CRF) by using food-grade microcrystalline wax (MW) and marine polysaccharide derivatives (calcium alginate and chitosan-glutaraldehyde copolymer). The pellets of water-soluble nitrogen fertilizer were coated with the marine polysaccharide derivatives and MW. A convenient and eco-friendly method was used to prepare the CRF. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and composition of the products. The nitrogen-release properties were determined in water using UV-Vis spectrophotometry. The controlled-release properties of the fertilizer were improved dramatically after coating with MW and the marine polysaccharide derivatives. The results show that the double-coated CRFs can release nitrogen in a controlled manner, have excellent controlled-release features, and meet the European Standard for CRFs.

  3. Preparation and characterization of controlled-release fertilizers coated with marine polysaccharide derivatives

    Science.gov (United States)

    Wang, Jing; Liu, Song; Qin, Yukun; Chen, Xiaolin; Xing, Rong'e.; Yu, Huahua; Li, Kecheng; Li, Pengcheng

    2016-10-01

    Encapsulation of water-soluble nitrogen fertilizers by membranes can be used to control the release of nutrients to maximize the fertilization effect and reduce environmental pollution. In this research, we formulated a new double-coated controlled-release fertilizer (CRF) by using food-grade microcrystalline wax (MW) and marine polysaccharide derivatives (calcium alginate and chitosan-glutaraldehyde copolymer). The pellets of water-soluble nitrogen fertilizer were coated with the marine polysaccharide derivatives and MW. A convenient and eco-friendly method was used to prepare the CRF. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and composition of the products. The nitrogen-release properties were determined in water using UV-Vis spectrophotometry. The controlled-release properties of the fertilizer were improved dramatically after coating with MW and the marine polysaccharide derivatives. The results show that the double-coated CRFs can release nitrogen in a controlled manner, have excellent controlled-release features, and meet the European Standard for CRFs.

  4. Dispersion of halloysite loaded with natural antimicrobials into pectins: Characterization and controlled release analysis.

    Science.gov (United States)

    Gorrasi, Giuliana

    2015-01-01

    This paper reports the preparation and characterization of green composites based on pectins and nano-hybrids composed of halloysite nanotubes (HNTs) loaded with rosemary essential oil. Different hybrid percentages were mixed into a pectin matrix, by ball milling in the presence of water. Cast films were obtained and analyzed. Structural organization and physical properties (thermal, mechanical, barrier to water vapor) were correlated to the nano-hybrid content. A preliminary study on the kinetics of release of the rosmarinic acid, chosen as a model molecule, was also performed. This work showed the potential of these systems in the active packaging field where controlled release of active species is required.

  5. Physicochemical characterization, in vitro release and permeation studies of respirable rifampicin-cyclodextrin inclusion complexes

    Directory of Open Access Journals (Sweden)

    Patil J

    2009-01-01

    Full Text Available The inclusion complexes of rifampicin with sucralose and β-cyclodextrins were prepared by spray drying method. The complexes were characterized by size analyses, scanning electron microscopy, differential scanning calorimetry and x-ray diffraction methods. The results indicated the amorphous nature of resultant products. The solubility, in vitro release and skin permeation of the drug were enhanced after formation of inclusion complexes. The in vitro release and permeation of the inclusion complexes were greater in simulated lung fluid as compared to pure drug.

  6. Tunable release of clavam from clavam stabilized gold nanoparticles — Design, characterization and antimicrobial study

    Energy Technology Data Exchange (ETDEWEB)

    Manju, V. [Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute, Karaikudi, Tamilnadu 630006 (India); Dhandapani, P. [Corrosion Materials and Protection Division, CSIR-Central Electrochemical Research Institute, Karaikudi, Tamilnadu, 630006 (India); Gurusamy Neelavannan, M. [Characterization and Measurement lab, CSIR-Central Electrochemical Research Institute, Karaikudi, Tamilnadu 630006 (India); Maruthamuthu, S. [Corrosion Materials and Protection Division, CSIR-Central Electrochemical Research Institute, Karaikudi, Tamilnadu, 630006 (India); Berchmans, S. [Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute, Karaikudi, Tamilnadu 630006 (India); Palaniappan, A., E-mail: palani112@gmail.com [Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute, Karaikudi, Tamilnadu 630006 (India)

    2015-04-01

    A facile one-step approach is developed to synthesize highly stable (up to 6 months) gold nanoparticles (GNPs) using Clavam, pharmaceutical form of amoxicillin which contains a mixture of amoxicillin and potassium salt of clavulanic acid, at room temperature (25–30 °C). The clavam stabilized GNPs are characterized using various techniques including UV–Visible, FT-IR spectrophotometry and transmission electron microscopy (TEM). Tunable release of clavam from clavam stabilized GNPs is demonstrated using intracellular concentrations of glutathione (GSH). The process is monitored using an UV–Vis spectroscopy and the amount of clavam released in terms of amoxicillin concentration is quantitatively estimated using reverse phase high performance liquid chromatographic (RP-HPLC) technique. In vitro study reveals that the clavam released from GNPs' surface was found to show a significant enhancement in antibacterial activity against Escherichia coli and the cause of enhancement is addressed. - Graphical abstract: Stable and nearly monodisperse gold nanoparticles (GNPs) are prepared at room temperature (~ 25–30 °C) using clavam; commercial form of amoxicillin antibiotic. Tunable release of clavam from clavam stabilized GNPs is demonstrated by the addition of varying concentrations of glutathione. Interactions between clavam and gold core are investigated in detail. The mechanism of enhanced antimicrobial activity of clavam released from clavam stabilized GNPs is probed. - Highlights: • Gold nanoparticles (GNPs) are prepared without reducing agent using antibiotic clavam{sup TR}. • Our work shed lights on the nature of interaction between the clavam and GNPs. • Sustained release of clavam from clavam stabilized GNPs is demonstrated using glutathione. • Antimicrobial activity of the released clavam is confirmed using various techniques. • Our study suggests that the clavam released from GNPs shows better inhibition of E. coli.

  7. Kinetic characterization of thermophilic and mesophilic anaerobic digestion for coffee grounds and waste activated sludge.

    Science.gov (United States)

    Li, Qian; Qiao, Wei; Wang, Xiaochang; Takayanagi, Kazuyuki; Shofie, Mohammad; Li, Yu-You

    2015-02-01

    This study was conducted to characterize the kinetics of an anaerobic process (hydrolysis, acetogenesis, acidogenesis and methanogenesis) under thermophilic (55 °C) and mesophilic (35 °C) conditions with coffee grounds and waste activated sludge (WAS) as the substrates. Special focus was given to the kinetics of propionic acid degradation to elucidate the accumulation of VFAs. Under the thermophilic condition, the methane production rate of all substrates (WAS, ground coffee and raw coffee) was about 1.5 times higher than that under the mesophilic condition. However, the effects on methane production of each substrate under the thermophilic condition differed: WAS increased by 35.8-48.2%, raw coffee decreased by 76.3-64.5% and ground coffee decreased by 74.0-57.9%. Based on the maximum reaction rate (Rmax) of each anaerobic stage obtained from the modified Gompertz model, acetogenesis was found to be the rate-limiting step for coffee grounds and WAS. This can be explained by the kinetics of propionate degradation under thermophilic condition in which a long lag-phase (more than 18 days) was observed, although the propionate concentration was only 500 mg/L. Under the mesophilic condition, acidogenesis and hydrolysis were found to be the rate-limiting step for coffee grounds and WAS, respectively. Even though reducing the particle size accelerated the methane production rate of coffee grounds, but did not change the rate-limiting step: acetogenesis in thermophilic and acidogenesis in mesophilic. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Degradation and drug release in calcium polyphosphate bioceramics: an MRI-based characterization.

    Science.gov (United States)

    Bray, J M; Filiaggi, M J; Bowen, C V; Beyea, S D

    2012-10-01

    Degradable, bioceramic bone implants made of calcium polyphosphate (CPP) hold potential for controlled release of therapeutic agents in the treatment of localized bone disease. Magnetic resonance imaging techniques for non-invasively mapping fluid distribution, T(1) and T(2) relaxation times and the apparent diffusion coefficient were performed in conjunction with a drug elution protocol to resolve free and bound water components within the material microstructure in two CPP formulations (G1 and G2). The T(2) maps provided the most accurate estimates of free and bound water, and showed that G1 disks contained a detectable free water component at all times, with drug release dominated by a Fickian diffusion mechanism. Drug release from G2 disks was characterized by a combined diffusional/structural relaxation mechanism, which may be related to the gradual infiltration of a free water component associated with swelling and/or chemical degradation.

  9. Preparation,Characterization,and in vitro Release of Biodegradable Erythromycin-gelatin Microspheres

    Institute of Scientific and Technical Information of China (English)

    WANG Fei; LIU Pai; JIANG Dan; LIU Cheng-bai; ZHANG Feng-chun; CHEN Xia

    2008-01-01

    Blank and erythromycin-loaded gelatin microspheres were successfully fabricated via emulsion chemical crosslinking technique.The surface morphology of the microspheres was characterized by scanning electron microscope(SEM)and optical microscope.The results show that the microspheres wcre spherical and smooth.The particle average size of erythromycin-loaded microspheres Was found to be 20.6 μm,with a high purity of more than 90%and with a good dispersibility.The microspheres could be obtained in a high yield.Erythromycin released from the microspheres Was monitored in buffer and artificial body fluid at 37℃.Average drug content was 27.2%, and erythromycin-loaded gelatin microspheres showed good release profiles with a nearly constant release during 4-8h in artificial body fluid in vitro degradation studies.These gelatin mierospheres are useful for studying and developing various drug-delivery systems.

  10. Tunable release of clavam from clavam stabilized gold nanoparticles--design, characterization and antimicrobial study.

    Science.gov (United States)

    Manju, V; Dhandapani, P; Gurusamy Neelavannan, M; Maruthamuthu, S; Berchmans, S; Palaniappan, A

    2015-04-01

    A facile one-step approach is developed to synthesize highly stable (up to 6months) gold nanoparticles (GNPs) using Clavam, pharmaceutical form of amoxicillin which contains a mixture of amoxicillin and potassium salt of clavulanic acid, at room temperature (25-30°C). The clavam stabilized GNPs are characterized using various techniques including UV-Visible, FT-IR spectrophotometry and transmission electron microscopy (TEM). Tunable release of clavam from clavam stabilized GNPs is demonstrated using intracellular concentrations of glutathione (GSH). The process is monitored using an UV-Vis spectroscopy and the amount of clavam released in terms of amoxicillin concentration is quantitatively estimated using reverse phase high performance liquid chromatographic (RP-HPLC) technique. In vitro study reveals that the clavam released from GNPs' surface was found to show a significant enhancement in antibacterial activity against Escherichia coli and the cause of enhancement is addressed. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Basic butylated methacrylate copolymer/kappa-carrageenan interpolyelectrolyte complex: preparation, characterization and drug release behaviour.

    Science.gov (United States)

    Prado, H J; Matulewicz, M C; Bonelli, P; Cukierman, A L

    2008-09-01

    The formation of a novel interpolyelectrolyte complex (IPEC) between basic butylated methacrylate copolymer and kappa-carrageenan was investigated and the product formed was characterized. Turbidity measurements and elemental analyses pointed to a 1:1 interaction of the repeating units. These results and FT-IR confirmed IPEC formation. Electronic microscopy images, particle size determination by image analysis and N(2) (77K) adsorption measurements were consistent with a porous material. This IPEC formed presented very good flowability and compactibility. Two maxima were observed in the swelling behaviour as a function of pH. The performance of the IPEC as a matrix for controlled release of drugs was evaluated, using ibuprofen as a model drug. Release profiles were properly represented by a mathematical model, which indicates that the system releases ibuprofen in a zero-order manner. These profiles could be controlled by conveniently modifying the proportion of the IPEC in the tablets.

  12. Characterizing Englacial Attenuation and Grounding Zone Geometry Using Airborne Radar Sounding

    Science.gov (United States)

    Schroeder, D. M.; Grima, C.; Blankenship, D. D.

    2014-12-01

    The impact of warm ocean water on ice sheet retreat and stability is a one of the primary drivers and sources of uncertainty for the rate of global sea level rise. One critical but challenging observation required to understand and model this impact is the location and extent of grounding ice sheet zones. However, existing surface topography based techniques do not directly detect the location where ocean water reaches (or breaches) grounded ice at the bed, which can significantly affect ice sheet stability. The primary geophysical tool for directly observing the basal properties of ice sheets is airborne radar sounding. However, uncertainty in englacial attenuation from unknown ice temperature and chemistry can lead to erroneous interpretation of subglacial conditions from bed echo strengths alone . Recently developed analysis techniques for radar sounding data have overcome this challenge by taking advantage of information in the angular distribution of bed echo energy and joint modeling of radar returns and water routing. We have developed similar approaches to analyze the spatial pattern and character of echoes to address the problems of improved characterization of grounding zone geometry and englacial attenuation. The spatial signal of the transition from an ice-bed interface to an ice-ocean interface is an increase in bed echo strength. However, rapidly changing attenuation near the grounding zone prevents the unambiguous interpretation of this signal in typical echo strength profiles and violates the assumptions of existing empirical attenuation correction techniques. We present a technique that treat bed echoes as continuous signals to take advantage of along-profile ice thickness and echo strength variations to constrain the spatial pattern of attenuation and detect the grounding zone transition. The transition from an ice-bed interface to an ice-ocean interface will also result in a change in the processes that determine basal interface morphology (e

  13. Preparation, characterization and related in vivo release, safety and toxicity studies of long acting lanreotide microspheres.

    Science.gov (United States)

    Wang, Shuang; Wu, Mingsheng; Li, Dan; Jiao, Mingli; Wang, Lan; Zhang, Haifeng; Liu, Huaiyu; Wang, Daifeng; Han, Bing

    2012-01-01

    The goal of this project was to prepare long-acting lanreotide acetate poly(lactic-co-glycolic acid) (PLGA) microspheres and to analyze the in vivo and in vitro release, safety and toxicology of these preparations. Long-acting lanreotide acetate PLGA microspheres that exhibited a 5-week slow-release period were prepared by a multiple-emulsion solvent evaporation method. Physical characterization, as well as the analysis of the in vivo and in vitro release, safety, acute toxicity and chronic toxicity of the lanreotide microspheres, were conducted in animal models in rats, guinea pigs, rabbits and beagle dogs. The lanreotide acetate PLGA microspheres prepared by multiple-emulsion solvent evaporation had smooth surfaces, uniform particle size and stable lanreotide loading. In vivo and in vitro experiments showed that the lanreotide acetate PLGA microspheres could continuously release lanreotide for 5 weeks. The safety of these long acting lanreotide microspheres was good in the following animal models: active systemic anaphylaxis test in guinea pigs, passive cutaneous anaphylaxis test in rats, hemolytic test in rabbits, local skin irritation test after subcutaneous administration in rabbits and muscle stimulation test in rabbits. Furthermore, no significant acute toxicity or chronic toxicity was observed after administration of lanreotide acetate PLGA microspheres in beagle dogs at dosages up to 22 mg/kg. The lanreotide acetate PLGA microspheres that were prepared in this study exhibited beneficial characteristics in apparent property and structural stability, as well as in release trends in vivo and in vitro.

  14. Regional Characterization of Metropolitan Areas in Japan for Strong Ground Motion Evaluation

    Science.gov (United States)

    Hirata, N.; Sato, H.; Koketsu, K.; Umeda, Y.; Iwata, T.; Kasahara, K.; Okaya, D.

    2002-12-01

    Introduction After the 1995 Kobe earthquake, the Japanese government increased its focus and funding of earthquake hazards evaluation, studies of man-made structures integrity, and emergency response planning in the major urban centers. A new agency, the Headquarters for Earthquake Research Promotion, was formed to oversee appropriate research in the earth sciences and civil engineering. This agency distributes research funds of \\$130 million per year. Projects include these topics: 1) Densification of seismic and GPS networks, 2) Paleoseismological investigation of major active faults, 3) Research on the geometry and physical properties of basins under the cities, 4) Probablistic strong ground motion estimation, and 5) Regional characterization of faults and physical parameters. Regional Characterization Study A long-term goal is to produce map of reliable estimations of strong ground motion. This requires accurate determination of: Source, Propagation path, Near surface and Ground motion response.A new five year project starts this year to characterize the "source" and "propagation path" in the Kanto (Tokyo) region and Kinki (Osaka) region. The proximity of the Pacific and Philippine Sea subducting plates requires study of the relationship between earthquakes and regional tectonics. This projects focuses on identification and geometry of: 1) Source faults, 2) Subducting plates and mega-thrust faults, 3)Crustal structure, 4) Seismogenic zone, 5) Sedimentary basins, 6) 3D velocity properties Reconstruction of source fault and velocity models allow for more realistic 3D EQ wave simulations. All of these information will be synthesized and provided to communities involved in probablistic hazards analysis, risk assessment and societal response. In 2002, we have started to deploy seismic profiling lines in the Boso Peninsula (112 km) and the Sagami bay area( 75 km) to image the subducting Philippine Sea plate

  15. Ground characterization and roof mapping:Online sensor signal-based change detection

    Institute of Scientific and Technical Information of China (English)

    Bahrampour Soheil; Rostami Jamal; Ray Asok; Naeimipour Ali; Collins Craig

    2015-01-01

    Measurement while drilling systems are becoming an important part of excavation operations for rock characterization and ground support design that require reliable information on rock strength and loca-tion&frequency of joints or voids. This paper focuses on improving rock characterization algorithms for instrumented roof-bolter systems. For this purpose, an improved void detection algorithm is proposed, where the underlying theory is built upon the concept of mean change detection based on the feed pressure signals. In addition, the application of acoustic sensing for void detection is examined and it is shown that the variance of the filtered acoustic signal is correlated to the strength of the material being drilled. The proposed algorithm has been validated on the data collected from full-scale drilling tests in various concrete and rock samples at the J. H. Fletcher facility.

  16. Structural Characterization of Calcium Alginate Matrices by Means of Mechanical and Release Tests

    Directory of Open Access Journals (Sweden)

    Romano Lapasin

    2009-08-01

    Full Text Available In this paper we have concentrated on the characterization of calcium alginate hydrogels loaded with a model drug (myoglobin by means of a mechanical approach; in addition, release tests of myoglobin from alginate hydrogels were performed. At a fixed temperature, relaxation tests (mechanical study were carried out on matrices constituted by different polymer concentrations. The interpretation of the relaxation behavior of the different matrices was conducted using the generalized Maxwell model; as a result of this investigation it was possible to conclude that for polymer concentrations greater than 0.5 g/ 100 mL the matrices behaved as solid materials. In addition, it was observed that the mechanical properties of the matrices increased with polymer concentration. With regard to the release tests, the diffusion coefficient of myoglobin in the matrix in relation to polymer concentrations was determined. The mechanical and release data where then analyzed by Flory’s theory and by a modified free-volume theory, respectively, to estimate the network mesh size ξ. The comparison between the mesh sizes obtained by the two approaches showed a satisfactory agreement for polymer concentrations greater than 0.5 g/100 mL. It should be noted that the approach proposed here to determine the polymeric network meshes is absolutely general and can be advantageously applied to the characterization of other similar polymeric systems.

  17. Salicylic acid and PEG-contained polyanhydrides: synthesis, characterization, and in vitro salicylic acid release.

    Science.gov (United States)

    Cai, Qixiang; Zhu, K J; Zhang, Jianxiang

    2005-01-01

    Poly [bi(o-carboxyphenyl)adipate-polyethylene glycol] anhydrides--P(BOCA-PEG)--polymeric drugs were synthesized and characterized by Fourier transformed infrared spectroscopy, NMR, DSC, gel permeation chromatography, etc. Salicylic acid loading efficiency of these polymers ranged from 43.5% to 71.3%, which was much higher than that of other polymeric drugs with salicylic acid. The in vitro release of salicylic acid from the polymers was carried out in buffer conditions with different pH values and and rat gastrointestinal contents. The results showed the release rate of salicylic acid increased with the increase of PEG content in the polymers and the increase of pH value of degradation buffer solution. The rat cecal contents also greatly promoted the release of salicylic acid. In 0.1M phosphate buffer solution at pH8.0, 37 degrees C containing 5% rat cecal contents, P(BOCA-PEG200)(80:20) had 15% salicylic acid released in 21 hr, indicating its potential use in colon-specific salicylic acid delivery.

  18. Obtaining of Sol-Gel Ketorolac-Silica Nanoparticles: Characterization and Drug Release Kinetics

    Directory of Open Access Journals (Sweden)

    T. M. López Goerne

    2013-01-01

    Full Text Available Nonsteroidal anti-inflammatory drugs (NSAIDs are among most commonly prescribed medications worldwide. NSAIDs play an important role due to their pronounced analgesic potency, anti-inflammatory effects, and lesser side effects compared to opioids. However, adverse effects including gastrointestinal and cardiovascular effects seriously complicate their prolonged use. In the present work we prepare SiO2-based nanoparticles with ketorolac, for controlled release proposes. The nanomaterials were prepared by the sol-gel technology at acidic conditions and two different water/alcoxide ratios were used. FTIR spectroscopy was performed in order to characterize the solids and drug-SiO2 interactions. Thermal analysis and nitrogen adsorption isotherms showed thermal stability of the drug and confirmed the presence of particles with high surface area. Transmission electron micrographies of the samples showed the nanosize particles (20 nm forming aggregates. Drug release profiles were collected by means of UV-Vis spectroscopy and kinetic analysis was developed. Release data were fitted and 1 : 8 sample showed a sustained release over ten hours; 90% of the drug was delivered at the end of the time.

  19. Characterization of biochars from different sources and evaluation of release of nutrients and contaminants

    Directory of Open Access Journals (Sweden)

    Natália Aragão de Figueredo

    Full Text Available ABSTRACT The biochar, product of pyrolysis of organic waste, has been used as a soil conditioner and alternative on solid waste management. However, the raw material and pyrolysis temperature used influence the quantity and dynamics of release of nutrients and contaminants from the biochar. The objective was to evaluate the use of waste sugarcane bagasse, eucalyptus and sewage sludge for production of biochar and determine the chemical, physical, mineralogical properties and acid extraction of these materials produced at 350 °C and 500 °C. Were evaluated the proportion of C, H, N, O; ashes; macro and micronutrients, plus some contaminants; characterization of mineral phases by diffractometry of X- rays; functional groups by infrared absorption spectroscopy (FTIR. Moreover, it was determined the release of nutrients and contaminants for the extraction in increasing concentration of HNO3 (0,01 - 2,0 mol L-1. The O/C and H/C relations decreased with increasing temperature of pyrolysis, which define a greater stability of the C of biochars. Sewage sludge biochar (BC-L had the highest nutrient release rates and contaminant metals (Cd, Cr, Ni and Pb. Acid extraction of other biochars was very low (<20% of the total content. The results indicate that the carbon fraction of biochar contributes to the low rate of release of the elements in acid place.

  20. Characterization of organogel as a novel oral controlled release formulation for lipophilic compounds.

    Science.gov (United States)

    Iwanaga, Kazunori; Sumizawa, Toru; Miyazaki, Makoto; Kakemi, Masawo

    2010-03-30

    A low molecular mass gelator can form soft solids in a variety of organic liquids and vegetable oils. These soft solids are generally called organogels. In this study, we prepared organogel using 12-hydroxystearic acid (12-HSA) as a gelator for soybean oil and investigated its characteristics as a controlled release formulation for lipophilic compounds. The release rate of ibuprofen, a model lipophilic compound, from organogel decreased with the increase of 12-HSA concentration in the formulation; however, the difference in the concentration of 12-HSA in the formulation did not affect the diffusivity of ibuprofen in the organogel. The erosion constant of organogel in the intestinal tract was examined by using simulated gastric fluid and intestinal fluid. Regardless of 12-HSA concentration in the formulation, organogel is very stable in the simulated gastric fluid. On the other hand, the erosion constant of organogel in the simulated intestinal fluid increased with the decreasing concentration of 12-HSA. Therefore, it is speculated that the difference in the release rate of ibuprofen among organogels with various concentrations of 12-HSA was mainly caused by the difference in the erosion rate. To characterize the organogel effect in vivo, ibuprofen was orally administered to rats in an aqueous suspension or organogel. Ibuprofen concentration in plasma rapidly increased after administration with an aqueous suspension, whereas organogel suppressed the rapid absorption. In conclusion, organogel is clearly useful as an oral controlled release formulation for lipophilic compounds.

  1. Characterization of Ground Deformation above AN Urban Tunnel by Means of Insar Time Series Analysis

    Science.gov (United States)

    Ferretti, A.; Iannacone, J.; Falorni, G.; Berti, M.; Corsini, A.

    2013-12-01

    Ground deformation produced by tunnel excavation in urban areas can cause damage to buildings and infrastructure. In these contexts, monitoring systems are required to determine the surface area affected by displacement and the rates of movement. Advanced multi-image satellite-based InSAR approaches are uniquely suited for this purpose as they provide an overview of the entire affected area and can measure movement rates with millimeter precision. Persistent scatterer approaches such as SqueeSAR™ use reflections off buildings, lampposts, roads, etc to produce a high-density point cloud in which each point has a time series of deformation spanning the period covered by the imagery. We investigated an area of about 10 km2 in North Vancouver, (Canada) where the shaft excavation of the Seymour-Capilano water filtration plant was started in 2004. As part of the project, twin tunnels in bedrock were excavated to transfer water from the Capilano Reservoir to the treatment plant. A radar dataset comprising 58 images (spanning March 2001 - June 2008) acquired by the Radarsat-1 satellite and covering the period of excavation was processed with the SqueeSAR™ algorithm (Ferretti et al., 2011) to assess the ground deformation caused by the tunnel excavation. To better characterize the deformation in the time and space domains and correlate ground movement with excavation, an in-depth time series analysis was carried out. Berti et al. (2013) developed an automatic procedure for the analysis of InSAR time series based on a sequence of statistical tests. The tool classifies time series into six distinctive types (uncorrelated; linear; quadratic; bilinear; discontinuous without constant velocity; discontinuous with change in velocity) which can be linked to different physical phenomena. It also provides a series of descriptive parameters which can be used to characterize the temporal changes of ground motion. We processed the movement time series with PSTime to determine the

  2. Chemical Characterization of the Aerosol During the CLAMS Experiment Using Aircraft and Ground Stations

    Science.gov (United States)

    Castanho, A. D.; Martins, J.; Artaxo, P.; Hobbs, P. V.; Remer, L.; Yamasoe, M.; Fattori, A.

    2002-05-01

    During the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) Experiment Nuclepore filters were collected in two ground stations and aboard the University of Wasghington's Convair 580 Reserarch Aircraft. The two ground stations were chosen in strategic positions to characterize the chemical composition, the mass concentration, black carbon (BC) content, and the absorption properties of the aerosol particles at the surface level. One of the stations was located at the Cheasapeake lighthouse (25 km from the coast) and the other one was located at the Wallops Island. Aerosol particles where collected in two stages, fine (d2.5um) and coarse mode (2.5characterize the elemental composition, mass concentration, BC content, and absorption properties of the aerosol in the atmospheric column in the CLAMS Experiment area. Some of the filters were also submitted to Scanning Electron Microscopy analysis. The particulate matter mass for all the samples were obtained gravimetrically. The concentration of black carbon in the fine filters was optically determined by a broadband reflectance technique. The spectral (from UV to near IR) reflectance in the fine and coarse mode filter were also obtained with a FieldSpec ASD spectrometer. Aerosol elemental characterization (Na through Pb) was obtained by the PIXE (Particle induced X ray emission) analyses of the nuclepore filters. The sources of the aerosol measured at the ground stations were estimated by principal component analyses mainly in the Wallops Island, where a longer time series was collected. One of the main urban components identified in the aerosol during the experiment was sulfate. Black carbon

  3. Polynitrosated polyesters: preparation, characterization, and potential use for topical nitric oxide release.

    Science.gov (United States)

    Seabra, Amedea B; da Silva, Regiane; de Oliveira, Marcelo G

    2005-01-01

    New nitric oxide (NO) donor macromolecules, containing multiple S-nitrosothiol (S-NO) groups covalently attached to the polymer backbone, were prepared through the polycondensation reaction of diols (ethylene glycol and poly(ethylene glycol)) with mercaptosuccinic acid, followed by the S-nitrosation of the SH groups by a gaseous NO/O2 mixture. The polynitrosated polyesters (PNPEs) obtained were characterized by IR spectroscopy and gel permeation chromatography and displayed biological activity as vasodilators, leading to local hyperaemia when applied topically on healthy skin. Kinetic measurements in either dry or aqueous conditions have shown that PNPEs can provide sustained NO release for more than 20 h at physiological temperature. Their increased viscosity at low temperatures greatly reduces the rate of NO release, allowing for their storage for more than 90 days at -20 degrees C without decomposition. These results indicate that PNPEs have potential for topical delivery of NO in biomedical applications.

  4. Development and In Vitro Characterization of Sustained Release Pellets of Venlafaxine Hydrochloride

    Directory of Open Access Journals (Sweden)

    P.REMYA

    2012-05-01

    Full Text Available The present study was undertaken with development and in-vitro characterization of sustained release pellets of venlafaxine hydrochloride by wruster process technique .which release the drug in sustained manner over a period of 20 hours. The different viscosity grades of polymers are HPMC-E6, Ethyl cellulose 7cps, MCC-101 were preparation of granules or pellets by wurster coating .The granules were prepared and evaluated for Angle of repose, bulk density, tapped density, cars index, moisture content, stability studies and dissolution studies were carried out. Formulation f1 and f2 can be considered as an optimized formulation for disperse the drug freely in GIT tract of venlafaxine HCl for getting more bioavailability.

  5. Quinoidal Oligo(9,10-anthryl)s with Chain-Length-Dependent Ground States: A Balance between Aromatic Stabilization and Steric Strain Release

    KAUST Repository

    Lim, Zhenglong

    2015-11-12

    Quinoidal π-conjugated polycyclic hydrocarbons have attracted intensive research interest due to their unique optical/electronic properties and possible magnetic activity, which arises from a thermally excited triplet state. However, there is still lack of fundamental understanding on the factors that determine the electronic ground states. Herein, by using quinoidal oligo(9,10-anthryl)s, it is demonstrated that both aromatic stabilisation and steric strain release play balanced roles in determining the ground states. Oligomers with up to four anthryl units were synthesised and their ground states were investigated by electronic absorption and electron spin resonance (ESR) spectroscopy, assisted by density functional theory (DFT) calculations. The quinoidal 9,10-anthryl dimer 1 has a closed-shell ground state, whereas the tri- (2) and tetramers (3) both have an open-shell diradical ground state with a small singlet-triplet gap. Such a difference results from competition between two driving forces: the large steric repulsion between the anthryl/phenyl units in the closed-shell quinoidal form that drives the molecule to a flexible open-shell diradical structure, and aromatic stabilisation due to the gain of more aromatic sextet rings in the closed-shell form, which drives the molecule towards a contorted quinoidal structure. The ground states of these oligomers thus depend on the overall balance between these two driving forces and show chain-length dependence. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Interim site characterization report and ground-water monitoring program for the Hanford site solid waste landfill

    Energy Technology Data Exchange (ETDEWEB)

    Fruland, R.M.; Hagan, R.A.; Cline, C.S.; Bates, D.J.; Evans, J.C.; Aaberg, R.L.

    1989-07-01

    Federal and state regulations governing the operation of landfills require utilization of ground-water monitoring systems to determine whether or not landfill operations impact ground water at the point of compliance (ground water beneath the perimeter of the facility). A detection-level ground-water monitoring system was designed, installed, and initiated at the Hanford Site Solid Waste Landfill (SWL). Chlorinated hydrocarbons were detected at the beginning of the ground-water monitoring program and continue to be detected more than 1 year later. The most probable source of the chlorinated hydrocarbons is washwater discharged to the SWL between 1985 and 1987. This is an interim report and includes data from the characterization work that was performed during well installation in 1987, such as field observations, sediment studies, and geophysical logging results, and data from analyses of ground-water samples collected in 1987 and 1988, such as field parameter measurements and chemical analyses. 38 refs., 27 figs., 8 tabs.

  7. Characterization of spontaneous, transient adenosine release in the caudate-putamen and prefrontal cortex.

    Science.gov (United States)

    Nguyen, Michael D; Lee, Scott T; Ross, Ashley E; Ryals, Matthew; Choudhry, Vishesh I; Venton, B Jill

    2014-01-01

    Adenosine is a neuroprotective agent that inhibits neuronal activity and modulates neurotransmission. Previous research has shown adenosine gradually accumulates during pathologies such as stroke and regulates neurotransmission on the minute-to-hour time scale. Our lab developed a method using carbon-fiber microelectrodes to directly measure adenosine changes on a sub-second time scale with fast-scan cyclic voltammetry (FSCV). Recently, adenosine release lasting a couple of seconds has been found in murine spinal cord slices. In this study, we characterized spontaneous, transient adenosine release in vivo, in the caudate-putamen and prefrontal cortex of anesthetized rats. The average concentration of adenosine release was 0.17±0.01 µM in the caudate and 0.19±0.01 µM in the prefrontal cortex, although the range was large, from 0.04 to 3.2 µM. The average duration of spontaneous adenosine release was 2.9±0.1 seconds and 2.8±0.1 seconds in the caudate and prefrontal cortex, respectively. The concentration and number of transients detected do not change over a four hour period, suggesting spontaneous events are not caused by electrode implantation. The frequency of adenosine transients was higher in the prefrontal cortex than the caudate-putamen and was modulated by A1 receptors. The A1 antagonist DPCPX (8-cyclopentyl-1,3-dipropylxanthine, 6 mg/kg i.p.) increased the frequency of spontaneous adenosine release, while the A1 agonist CPA (N(6)-cyclopentyladenosine, 1 mg/kg i.p.) decreased the frequency. These findings are a paradigm shift for understanding the time course of adenosine signaling, demonstrating that there is a rapid mode of adenosine signaling that could cause transient, local neuromodulation.

  8. Characterization of silver release from commercially available functional (nano)textiles.

    Science.gov (United States)

    Lorenz, C; Windler, L; von Goetz, N; Lehmann, R P; Schuppler, M; Hungerbühler, K; Heuberger, M; Nowack, B

    2012-10-01

    Silver, both in the nano as well as in other forms, is used in many applications including antimicrobial textiles. Washing of such textiles has already been identified as an important process that results in the release of silver into wastewater. This study thus investigated the release of silver from eight different commercially available silver-textiles during a washing and rinsing cycle. The silver released was size-fractionated and characterized using electron microscopy. In addition, the antimicrobial functionality of the textiles was tested before and after washing. Three of the textiles contained nanosized silver (labeled or confirmed by manufacturers' information), another used a metallic silver wire and four contained silver in undeclared form. The initial silver content of the textiles was between 1.5 and 2925mg Ag/kg. Only four of the investigated textiles leached detectable amounts of silver, of which 34-80% was in the form of particles larger than 450nm. Microscopic analysis of the particles released in the washing solutions identified Ti/Si-AgCl nanocomposites, AgCl nanoparticles, large AgCl particles, nanosilver sulfide and metallic nano-Ag, respectively. The nanoparticles were mainly found in highly agglomerated form. The identified nanotextiles showed the highest antimicrobial activity, whereas some of the other textiles, e.g. the one with a silver wire and the one with the lowest silver content, did not reduce the growth of bacteria at all. The results show that different silver textiles release different forms of silver during washing and that among the textiles investigated AgCl was the most frequently observed chemical form in the washwater.

  9. Characterizing the Performance of Haleakala as a Ground Site for Laser Communications

    Science.gov (United States)

    Felton, B.; Alliss, R.

    Radio Frequency (RF) signals have been relied on exclusively and successfully to communicate with spacecraft since satellite communications began nearly 60 years ago. However, missions now demand higher data rates to meet their data collection requirements. In response to this need, several organizations have begun to take steps to increase the data capacity of future missions by developing laser communications terminals and operational concepts for future missions. For example, NASA's Lunar Laser Communications Demonstration (LLCD) successfully demonstrated high data rate communications links to and from the LADEE satellite orbiting the moon during the Fall of 2013. As a next step, the Laser Communication Relay Demonstration (LCRD) will build upon the experience gained from LLCD and perform multi-year testing of Free-Space Optical Communications (FSOC) from geosynchronous orbit. Planning for these missions has included identifying candidate ground station locations, quantifying the impacts of the atmosphere on the data links, and developing operational concepts for mitigating transmission losses due to clouds, turbulence, and aerosols. Since space-to-ground optical communications are adversely affected by the presence of clouds, turbulence, and other atmospheric phenomena, it is important to study the effects of the atmosphere on the communications link. To support this, Northrop Grumman is leading a campaign to measure and model the atmospheric effects on the link between a ground station on the summit of Haleakala and a satellite in geostationary orbit. Part of this effort involves using a modified version of the Weather Research & Forecast (WRF) model to generate long-term climatologies of optical turbulence parameters as well as to characterize the atmosphere along the line-of-sight (LOS) from the ground station to the satellite during operations to be used as a link diagnostic tool. While ground-based instruments can be used to measure the effects of

  10. Characterization of the Aerodynamic Ground Effect and Its Influence in Multirotor Control

    National Research Council Canada - National Science Library

    Pedro Sanchez-Cuevas; Guillermo Heredia; Anibal Ollero

    2017-01-01

    This paper analyzes the ground effect in multirotors, that is, the change in the thrust generated by the rotors when flying close to the ground due to the interaction of the rotor airflow with the ground surface...

  11. Ampicillin-Ester Bonded Branched Polymers: Characterization, Cyto-, Genotoxicity and Controlled Drug-Release Behaviour

    Directory of Open Access Journals (Sweden)

    Ewa Oledzka

    2014-06-01

    Full Text Available The development and characterization of novel macromolecular conjugates of ampicillin using branched biodegradable polymers has been described in this study. The conjugates have been prepared coupling the β-lactam antibiotic with branched polymer matrices based on the natural oligopeptide core. The cyto- and genotoxicity of the synthesized polymers were evaluated with a bacterial luminescence test, two protozoan assays and Salmonella typhimurium TA1535. The presence of a newly formed covalent bond between the drug and the polymer matrices was confirmed by 1H-NMR and FTIR studies. A drug content (15.6 and 10.2 mole % in the macromolecular conjugates has been determined. The obtained macromolecular products have been subjected to further in vitro release studies. The total percentage of ampicillin released after 21 days of incubation was nearly 60% and 14% and this resulted from the different physicochemical properties of the polymeric matrices. This is the first report on the application of branched biodegradable polymeric matrices for the covalent conjugation of ampicillin. The obtained results showed that the synthesized macromolecular drug-conjugates might slowly release the active drug molecule and improve the pharmacokinetics of ampicillin.

  12. Synthesis, characterization, and in vitro release of diclofenac sodium from hybrid nanostructured magnetite-calcium pectinate

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Raj Kumar, E-mail: duttafcy@iitr.ernet.in; Sahu, Saurabh, E-mail: saurabhsahu12@gmail.com [Indian Institute of Technology Roorkee, Analytical Chemistry Laboratory, Department of Chemistry (India); Reddy, V. R., E-mail: vrreddy@csr.res.in [UGC-DAE Consortium for Scientific Research (India)

    2012-08-15

    A stable spherical nanostructured calcium pectinate loaded with diclofenac sodium (DS) and functionalized by superparamagnetic iron oxide nanoparticles, referred as MCPDS, was developed as a potential magnetically targeted drug delivery system. The sizes of the MCPDS were in the range of 100-200 nm in dried condition, confirmed by scanning electron microscopy and transmission electron microscopy. In the aqueous medium, the sizes of MCPDS were in the range 300 {+-} 50 nm, measured by dynamic light scattering technique. The X-ray diffraction and {sup 57}Fe Moessbauer spectroscopy confirmed magnetite phase in MCPDS. The magnetic property of the MCPDS nanostructures was confirmed from high saturation magnetization (44.05 emu/g), measured using a vibrating sample magnetometer. The superparamagnetic property of MCPDS was characterized by superconducting quantum unit interference device magnetometry and corroborated by Moessbauer spectroscopy. The loading efficiency of DS in MCPDS was measured by UV-Vis spectrophotometry and corroborated by thermal analysis. The in vitro release of the drug from MCPDS in simulated gastrointestinal fluids and in phosphate buffer solution was found to be pH sensitive and exhibited sustained release property. The cumulative drug release agreed well with that of swelling controlled diffusion mechanism, given by the Korsemeyer Peppas model.

  13. Release Properties and Electrochemical Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

    Science.gov (United States)

    Pearman, B. P.; Calle, L. M.; Zhang, X.; Li, W.; Buhrow, J. W.; Johnsey, M. N.; Montgomery, E. L.; Fitzpatrick, L.; Surma, J. M.

    2015-01-01

    The NASA Kennedy Space Center's Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion indicators, inhibitors and self-healing agents. This allows for the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods. Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The total inhibitor content and the release of one of the inhibitors from the microparticles in basic solution was measured. Particles with inhibitor contents of up 60 wt% were synthesized. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed. The inhibition efficacy of the inhibitors, both as the pure materials and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

  14. Synthesis, characterization and the release kinetics of antiproliferative agents from polyamidoamine conjugates.

    Science.gov (United States)

    Aderibigbe, B A; Sadiku, E R; Ray, S S; Mbianda, X Y; Fotsing, M C; Jayaramudu, J; Owonubi, S J

    2015-01-01

    Polyamidoamine conjugates containing curcumin and bisphosphonate were synthesized via a one-pot aqueous phase Michael addition reaction. In the design of the conjugate, bisphosphonate formed an integral part of the polymer carrier backbone. Curcumin was incorporated onto the polyamidoamine backbone via piperazine linker. The conjugates were characterized by Fourier transform spectroscopy, energy-dispersive X-ray analysis, atomic force spectroscopy and nuclear magnetic resonance spectroscopy and it confirmed the successful incorporation of the antiproliferative agents onto the carriers. The weight percentage incorporation of bisphosphonate to the carriers was found to be between 2.56% and 3.34%. The in vitro release studies of curcumin from the polyamidoamine conjugate were performed in dialysis bag at selected pH values. The release of curcumin was significantly slower at pH 7.4 when compared to pH 5.8. The release profiles indicate that the conjugates are more stable at pH 7.4 and are potential sustained drug-delivery systems for combination therapy.

  15. Characterization of absorbing aerosol types using ground and satellites based observations over an urban environment

    Science.gov (United States)

    Bibi, Samina; Alam, Khan; Chishtie, Farrukh; Bibi, Humera

    2017-02-01

    In this paper, for the first time, an effort has been made to seasonally characterize the absorbing aerosols into different types using ground and satellite based observations. For this purpose, optical properties of aerosol retrieved from AErosol RObotic NETwork (AERONET) and Ozone Monitoring Instrument (OMI) were utilized over Karachi for the period 2012 to 2014. Firstly, OMI AODabs was validated with AERONET AODabs and found to have a high degree of correlation. Then, based on this validation, characterization was conducted by analyzing aerosol Fine Mode Fraction (FMF), Angstrom Exponent (AE), Absorption Angstrom Exponent (AAE), Single Scattering Albedo (SSA) and Aerosol Index (AI) and their mutual correlation, to identify the absorbing aerosol types and also to examine the variability in seasonal distribution. The absorbing aerosols were characterized into Mostly Black Carbon (BC), Mostly Dust and Mixed BC & Dust. The results revealed that Mostly BC aerosols contributed dominantly during winter and postmonsoon whereas, Mostly Dust were dominant during summer and premonsoon. These types of absorbing aerosol were also confirmed with MODerate resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) observations.

  16. Airborne and Ground-Based Optical Characterization of Legacy Underground Nuclear Test Sites

    Science.gov (United States)

    Vigil, S.; Craven, J.; Anderson, D.; Dzur, R.; Schultz-Fellenz, E. S.; Sussman, A. J.

    2015-12-01

    Detecting, locating, and characterizing suspected underground nuclear test sites is a U.S. security priority. Currently, global underground nuclear explosion monitoring relies on seismic and infrasound sensor networks to provide rapid initial detection of potential underground nuclear tests. While seismic and infrasound might be able to generally locate potential underground nuclear tests, additional sensing methods might be required to further pinpoint test site locations. Optical remote sensing is a robust approach for site location and characterization due to the ability it provides to search large areas relatively quickly, resolve surface features in fine detail, and perform these tasks non-intrusively. Optical remote sensing provides both cultural and surface geological information about a site, for example, operational infrastructure, surface fractures. Surface geological information, when combined with known or estimated subsurface geologic information, could provide clues concerning test parameters. We have characterized two legacy nuclear test sites on the Nevada National Security Site (NNSS), U20ak and U20az using helicopter-, ground- and unmanned aerial system-based RGB imagery and light detection and ranging (lidar) systems. The multi-faceted information garnered from these different sensing modalities has allowed us to build a knowledge base of how a nuclear test site might look when sensed remotely, and the standoff distances required to resolve important site characteristics.

  17. Atmospheric aerosol characterization with a ground-based SPEX spectropolarimetric instrument

    Directory of Open Access Journals (Sweden)

    G. van Harten

    2014-06-01

    Full Text Available Characterization of atmospheric aerosols is important for understanding their impact on health and climate. A wealth of aerosol parameters can be retrieved from multi-angle, multi-wavelength radiance and polarization measurements of the clear sky. We developed a ground-based SPEX instrument (groundSPEX for accurate spectropolarimetry, based on the passive, robust, athermal and snapshot spectral polarization modulation technique, and hence ideal for field deployment. It samples the scattering phase function in the principal plane in an automated fashion, using a motorized pan/tilt unit and automatic exposure time detection. Extensive radiometric and polarimetric calibrations were performed, yielding values for both random noise and systematic uncertainties. The absolute polarimetric accuracy at low degrees of polarization is established to be ~ 5 × 10−3. About 70 measurement sequences have been performed throughout four clear-sky days at Cabauw, the Netherlands. Several aerosol parameters were retrieved: aerosol optical thickness, effective radius, and complex refractive index for fine and coarse mode. The results are in good agreement with the co-located AERONET products, with a correlation coefficient of ρ = 0.932 for the total aerosol optical thickness at 550 nm.

  18. Chemical Characterization of Potentially Prebiotic Oligosaccharides in Brewed Coffee and Spent Coffee Grounds.

    Science.gov (United States)

    Tian, Tian; Freeman, Samara; Corey, Mark; German, J Bruce; Barile, Daniela

    2017-04-05

    Oligosaccharides are indigestible carbohydrates widely present in mammalian milk and in some plants. Milk oligosaccharides are associated with positive health outcomes; however, oligosaccharides in coffee have not been extensively studied. We investigated the oligosaccharides and their monomeric composition in dark roasted coffee beans, brewed coffee, and spent coffee grounds. Oligosaccharides with a degree of polymerization ranging from 3 to 15, and their constituent monosaccharides, were characterized and quantified. The oligosaccharides identified were mainly hexoses (potentially galacto-oligosaccharides and manno-oligosaccharides) containing a heterogeneous mixture of glucose, arabinose, xylose, and rhamnose. The diversity of oligosaccharides composition found in these coffee samples suggests that they could have selective prebiotic activity toward specific bacterial strains able to deconstruct the glycosidic bonds and utilize them as a carbon source.

  19. Regional Characterization of the Crust in Metropolitan Areas for Prediction of Strong Ground Motion

    Science.gov (United States)

    Hirata, N.; Sato, H.; Koketsu, K.; Umeda, Y.; Iwata, T.; Kasahara, K.

    2003-12-01

    Introduction: After the 1995 Kobe earthquake, the Japanese government increased its focus and funding of earthquake hazards evaluation, studies of man-made structures integrity, and emergency response planning in the major urban centers. A new agency, the Ministry of Education, Science, Sports and Culture (MEXT) has started a five-year program titled as Special Project for Earthquake Disaster Mitigation in Urban Areas (abbreviated to Dai-dai-toku in Japanese) since 2002. The project includes four programs: I. Regional characterization of the crust in metropolitan areas for prediction of strong ground motion. II. Significant improvement of seismic performance of structure. III. Advanced disaster management system. IV. Investigation of earthquake disaster mitigation research results. We will present the results from the first program conducted in 2002 and 2003. Regional Characterization of the Crust in Metropolitan Areas for Prediction of Strong Ground Motion: A long-term goal is to produce map of reliable estimations of strong ground motion. This requires accurate determination of ground motion response, which includes a source process, an effect of propagation path, and near surface response. The new five-year project was aimed to characterize the "source" and "propagation path" in the Kanto (Tokyo) region and Kinki (Osaka) region. The 1923 Kanto Earthquake is one of the important targets to be addressed in the project. The proximity of the Pacific and Philippine Sea subducting plates requires study of the relationship between earthquakes and regional tectonics. This project focuses on identification and geometry of: 1) Source faults, 2) Subducting plates and mega-thrust faults, 3) Crustal structure, 4) Seismogenic zone, 5) Sedimentary basins, 6) 3D velocity properties We have conducted a series of seismic reflection and refraction experiment in the Kanto region. In 2002 we have completed to deploy seismic profiling lines in the Boso peninsula (112 km) and the

  20. Morphologic and proteomic characterization of exosomes released by cultured extravillous trophoblast cells

    Energy Technology Data Exchange (ETDEWEB)

    Atay, Safinur [Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY (United States); Gercel-Taylor, Cicek [Obstetrics, Gynecology and Women' s Health, University of Louisville School of Medicine, Louisville, KY (United States); Kesimer, Mehmet [Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States); Taylor, Douglas D., E-mail: ddtaylor@louisville.edu [Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY (United States); Obstetrics, Gynecology and Women' s Health, University of Louisville School of Medicine, Louisville, KY (United States)

    2011-05-01

    Exosomes represent an important intercellular communication vehicle, mediating events essential for the decidual microenvironment. While we have demonstrated exosome induction of pro-inflammatory cytokines, to date, no extensive characterization of trophoblast-derived exosomes has been provided. Our objective was to provide a morphologic and proteomic characterization of these exosomes. Exosomes were isolated from the conditioned media of Swan71 human trophoblast cells by ultrafiltration and ultracentrifugation. These were analyzed for density (sucrose density gradient centrifugation), morphology (electron microscopy), size (dynamic light scattering) and protein composition (Ion Trap mass spectrometry and western immunoblotting). Based on density gradient centrifugation, microvesicles from Sw71 cells exhibit a density between 1.134 and 1.173 g/ml. Electron microscopy demonstrated that microvesicles from Sw71 cells exhibit the characteristic cup-shaped morphology of exosomes. Dynamic light scattering showed a bell-shaped curve, indicating a homogeneous population with a mean size of 165 nm {+-} 0.5 nm. Ion Trap mass spectrometry demonstrated the presence of exosome marker proteins (including CD81, Alix, cytoskeleton related proteins, and Rab family). The MS results were confirmed by western immunoblotting. Based on morphology, density, size and protein composition, we defined the release of exosomes from extravillous trophoblast cells and provide their first extensive characterization. This characterization is essential in furthering our understanding of 'normal' early pregnancy.

  1. Characterization of the Hanford 300 area burial grounds. Final report: decontamination and decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, S.J.; Ames, L.L.; Fitzner, R.E.; Gee, G.W.; Sandness, G.A.; Simmons, C.S.

    1980-01-01

    Pacific Northwest Laboratory conducted a series of investigations at the Hanford Site to develop technologies for characterizing and monitoring radioactive waste burial facilities that could be used in determining appropriate decommissioning alternatives. Specific objectives were to develop unique functional geophysics, geochemical, soil physics, numerical modeling, and biological methodologies needed to better characterize and monitor buried radioactive waste disposal sites. To meet these objectives the project was divided into four tasks: Task I, Geophysical Evaluation - Geophysical surveys were taken to locate and define the gross composition of waste materials. Task II, Geochemical Analysis - The interaction of disposed radionuclides with geologic media was analyzed through an integrated radiochemical procedure. Task III, Fluid Transport and Modeling - Computer modeling of water migration in partially saturated groundwater systems was verified with actual data collected at a field test facility used to monitor micrometeorological and geohydrological energy and mass transfer factors. Task IV, Biological Transport - Several biological organisms were evaluated for potential radionuclide uptake and transport. Along with the four tasks, the project included a review of pertinent literature and regulatory issues that might affect the alternatives selected. Surveys were taken of the surrounding area and specific sites and operations. The overall results indicated that the 300 Area Burial Grounds have been adequate in containing radioactive waste. Based on the results of the project, the alternatives identified for decommissioning these sites are exhumation and translocation, entombment, perpetual care, and abandonment. Perpetual care (currently used) appears to be the best decommissioning alternative for these burial grounds at this time. However, another alternative may be selected depending on future waste management policies, plans, or activities.

  2. Characterizing topological order by studying the ground States on an infinite cylinder.

    Science.gov (United States)

    Cincio, L; Vidal, G

    2013-02-08

    Given a microscopic lattice Hamiltonian for a topologically ordered phase, we propose a numerical approach to characterize its emergent anyon model and, in a chiral phase, also its gapless edge theory. First, a tensor network representation of a complete, orthonormal set of ground states on a cylinder of infinite length and finite width is obtained through numerical optimization. Each of these ground states is argued to have a different anyonic flux threading through the cylinder. Then a quasiorthogonal basis on the torus is produced by chopping off and reconnecting the tensor network representation on the cylinder. From these two bases, and by using a number of previous results, most notably the recent proposal of Y. Zhang et al. [Phys. Rev. B 85, 235151 (2012)] to extract the modular U and S matrices, we obtain (i) a complete list of anyon types i, together with (ii) their quantum dimensions d(i) and total quantum dimension D, (iii) their fusion rules N(ij)(k), (iv) their mutual statistics, as encoded in the off-diagonal entries S(ij) of S, (v) their self-statistics or topological spins θ(i), (vi) the topological central charge c of the anyon model, and, in a chiral phase (vii) the low energy spectrum of each sector of the boundary conformal field theory. As a concrete application, we study the hard-core boson Haldane model by using the two-dimensional density matrix renormalization group. A thorough characterization of its universal bulk and edge properties unambiguously shows that it realizes a ν=1/2 bosonic fractional quantum Hall state.

  3. In situ characterization of forest litter using ground-penetrating radar

    Science.gov (United States)

    André, Frédéric; Jonard, François; Jonard, Mathieu; Lambot, Sébastien

    2016-03-01

    Decomposing litter accumulated on the soil surface in forests plays a major role in several ecosystem processes; its detailed characterization is therefore essential for thorough understanding of ecosystem functioning. In addition, litter is known to affect remote sensing radar data over forested areas and their proper processing requires accurate quantification of litter scattering properties. In the present study, ultrawideband (0.8-2.2 GHz) ground-penetrating radar (GPR) data were collected in situ for a wide range of litter types to investigate the potential of the technique to reconstruct litter horizons in undisturbed natural conditions. Radar data were processed resorting to full-wave inversion. Good agreement was generally found between estimated and measured litter layer thicknesses, with root-mean-square error values around 1 cm for recently fallen litter (OL layer) and around 2 cm for fragmented litter in partial decomposition (OF layer) and total litter (OL + OF). Nevertheless, significant correlations between estimated and measured thicknesses were found for total litter only. Inaccuracies in the reconstruction of the individual litter horizons were mainly attributed to weak dielectric contrasts amongst litter layers, with absolute differences in relative dielectric permittivity values often lower than 2 between humus horizons, and to uncertainties in the ground truth values. Radar signal inversions also provided reliable estimates of litter electromagnetic properties, with average relative dielectric permittivity values around 2.9 and 6.3 for OL and OF litters, respectively. These results are encouraging for the use of GPR for noninvasive characterization and mapping of forest litter. Perspectives for the application of the technique in biogeosciences are discussed.

  4. Carbon fiber plume sampling for large scale fire tests at Dugway Proving Ground. [fiber release during aircraft fires

    Science.gov (United States)

    Chovit, A. R.; Lieberman, P.; Freeman, D. E.; Beggs, W. C.; Millavec, W. A.

    1980-01-01

    Carbon fiber sampling instruments were developed: passive collectors made of sticky bridal veil mesh, and active instruments using a light emitting diode (LED) source. These instruments measured the number or number rate of carbon fibers released from carbon/graphite composite material when the material was burned in a 10.7 m (35 ft) dia JP-4 pool fire for approximately 20 minutes. The instruments were placed in an array suspended from a 305 m by 305 m (1000 ft by 1000 ft) Jacob's Ladder net held vertically aloft by balloons and oriented crosswind approximately 140 meters downwind of the pool fire. Three tests were conducted during which released carbon fiber data were acquired. These data were reduced and analyzed to obtain the characteristics of the released fibers including their spatial and size distributions and estimates of the number and total mass of fibers released. The results of the data analyses showed that 2.5 to 3.5 x 10 to the 8th power single carbon fibers were released during the 20 minute burn of 30 to 50 kg mass of initial, unburned carbon fiber material. The mass released as single carbon fibers was estimated to be between 0.1 and 0.2% of the initial, unburned fiber mass.

  5. Estimation of the release and migration of lead through soils and groundwater at the Hanford Site 218-E-12B Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    Rhoads, K.; Bjornstad, B.N.; Lewis, R.E.; Teel, S.S.; Cantrell, K.J.; Serne, R.J.; Smoot, J.L.; Kincaid, C.T.; Wurstner, S.K.

    1992-10-01

    This report describes the technical basis for a groundwater transport analysis that was conducted to evaluate migration of potentially hazardous materials from the Hanford Site 218-E-12B burial ground. The analysis characterized the geologic, chemical, and hydrologic properties of the disposal site, and used that information to perform a screening analysis for transport of materials from the burial ground to downgradient groundwater locations and to the Columbia River. Subsequent sections of the appendix describe the geologic setting, geochemistry, and hydrology of the disposal site and their relationship to the transport analysis.

  6. Estimation of the release and migration of lead through soils and groundwater at the Hanford Site 218-E-12B Burial Ground. Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Rhoads, K.; Bjornstad, B.N.; Lewis, R.E.; Teel, S.S.; Cantrell, K.J.; Serne, R.J.; Smoot, J.L.; Kincaid, C.T.; Wurstner, S.K.

    1992-10-01

    This report describes the technical basis for a groundwater transport analysis that was conducted to evaluate migration of potentially hazardous materials from the Hanford Site 218-E-12B burial ground. The analysis characterized the geologic, chemical, and hydrologic properties of the disposal site, and used that information to perform a screening analysis for transport of materials from the burial ground to downgradient groundwater locations and to the Columbia River. Subsequent sections of the appendix describe the geologic setting, geochemistry, and hydrology of the disposal site and their relationship to the transport analysis.

  7. Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

    1984-05-01

    This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage.

  8. Data acquisition and processing system for drug release characterization by thin layer chromatography.

    Science.gov (United States)

    Ryoo, J P; Greer, R; Carlson, D

    1989-01-01

    Samples of an antibiotic released from an ocular insert in an in vitro test are characterized by thin layer chromatography (TLC). Conventional characterization methods include cutting and weighing strip chart paper peak profiles obtained with a scanning densitometer for spotted TLC plates, and relating peaks for unknowns to peaks for standards on the basis of relative weights. A data collection and processing system is described in which the data collection and processing is highly automated utilizing a specially developed software program. A Kontes densitometer (Model 800) and a personal computer (IBM PC-AT or Zenith-248) are interfaced using a Keithley 570 data acquisition system. Two BASIC software programs were developed to provide quantitative evaluation of chromatograms of an antibiotic (tylosin tartrate); the first program generates chromatograms on the computer screen through initiating controlled operation of a scanning densitometer for TLC plate analysis, and the second program processes the data providing quantitative analysis of the spectral output through a peak detection and peak integration routine. The approach represents a new general, versatile, quick and effective method to characterize TLC samples for various numbers of peaks for unknowns and standards for different concentration levels.

  9. Synthesis, characterization, release kinetics and toxicity profile of drug-loaded starch nanoparticles.

    Science.gov (United States)

    El-Naggar, Mehrez E; El-Rafie, M H; El-sheikh, M A; El-Feky, Gina S; Hebeish, A

    2015-11-01

    The current research work focuses on the medical application of the cost-effective cross-linked starch nanoparticles, for the transdermal delivery using Diclofenac sodium (DS) as a model drug. The prepared DS-cross-linked starch nanoparticles were synthesized using nanoprecipitation technique at different concentrations of sodium tripolyphosphate (STPP) in the presence of Tween 80 as a surfactant. The resultant cross-linked starch nanoparticles loaded with DS were characterized using world-class facilities such as TEM, DLS, FT-IR, XRD, and DSc. The efficiency of DS loading was also evaluated via entrapment efficiency as well as in vitro release and histopathological study on rat skin. The optimum nanoparticles formulation selected by the JMP(®) software was the formula that composed of 5% maize starch, 57.7mg DS and 0.5% STPP and 0.4% Tween 80, with particle diameter of about 21.04nm, polydispersity index of 0.2 and zeta potential of -35.3mV. It is also worth noting that this selected formula shows an average entrapment efficiency of 95.01 and sustained DS release up to 6h. The histophathological studies using the best formula on rat skin advocate the use of designed transdermal DS loaded cross-linked starch nanoparticles as it is safe and non-irritant to rat skin. The overall results indicate that, the starch nanoparticles could be considered as a good carrier for DS drug regarding the enhancement in its controlled release and successful permeation, thus, offering a promising nanoparticulate system for the transdermal delivery non-steroidal anti-inflammatory drug (NSAID).

  10. Towards improved characterization of high-risk releases using heterogeneous indoor sensor systems

    Energy Technology Data Exchange (ETDEWEB)

    Sreedharan, Priya; Sohn, Michael D.; Nazaroff, William W.; J. Gadgil, Ashok

    2010-06-30

    The sudden release of toxic contaminants that reach indoor spaces can be hazardous to building occupants. For an acutely toxic contaminant, the speed of the emergency response strongly influences the consequences to occupants. The design of a real time sensor system is made challenging both by the urgency and complex nature of the event, and by the imperfect sensors and models available to describe it. In this research, we use Bayesian modeling to combine information from multiple types of sensors to improve the characterization of a release. We discuss conceptual and algorithmic considerations for selecting and fusing information from disparate sensors. To explore system performance, we use both real tracer gas data from experiments in a three story building, along with synthetic data, including information from door position sensors. The added information from door position sensors is found to be useful for many scenarios, but not always. We discuss the physical conditions and design factors that affect these results, such as the influence of the door positions on contaminant transport. We highlight potential benefits of multisensor data fusion, challenges in realizing those benefits, and opportunities for further improvement.

  11. Characterization of lysosome-destabilizing DOPE/PLGA nanoparticles designed for cytoplasmic drug release.

    Science.gov (United States)

    Chhabra, Resham; Grabrucker, Andreas M; Veratti, Patrizia; Belletti, Daniela; Boeckers, Tobias M; Vandelli, Maria Angela; Forni, Flavio; Tosi, Giovanni; Ruozi, Barbara

    2014-08-25

    Polymeric nanoparticles (NPs) offer a promising approach for therapeutic intracellular delivery of proteins, conventionally hampered by short half-lives, instability and immunogenicity. Remarkably, NPs uptake occurs via endocytic internalization leading to NPs content's release within lysosomes. To overcome lysosomal degradation and achieve NPs and/or loaded proteins release into cytosol, we propose the formulation of hybrid NPs by adding 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as pH sensitive component in the formulation of poly-lactide-co-glycolide (PLGA) NPs. Hybrid NPs, featured by different DOPE/PLGA ratios, were characterized in terms of structure, stability and lipid organization within the polymeric matrix. Experiments on NIH cells and rat primary neuronal cultures highlighted the safety profile of hybrid NPs. Moreover, after internalization, NPs are able to transiently destabilize the integrity of lysosomes in which they are taken up, speeding their escape and favoring cytoplasmatic localization. Thus, these DOPE/PLGA-NPs configure themselves as promising carriers for intracellular protein delivery.

  12. Quinoline based polymeric drug for biological applications: synthesis, characterization, antimicrobial, and drug releasing studies.

    Science.gov (United States)

    Uma, P; Suresh, J; Selvaraj, Revathy; Karthik, S; Arun, A

    2015-01-01

    Novel acrylate monomer of quinoline-based chalcone 1-(4-(7-chloroquinolin-4-ylamino)phenyl) acrylate (CPA) was synthesized using (4-(2-chloroquinolin-5-ylamino)phenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one (CPE) and acryloyl chloride. CPA is characterized by different techniques like IR, (1)H NMR and UV-visible spectrometry techniques. Poly(CPA), poly(CPA-co-AA) and poly(CPA-co-HEA) are prepared by solution polymerization technique using CPA, acrylic acid (AA) and hydroxyethylacrylate (HEA), respectively. The antimicrobial activities of the compounds are tested using four different micro-organisms. In vitro cumulative drug release studies are done using UV visible spectroscopic technique. The molecular weights of these polymers are found to be around 5000 g/mol. The synthesized polymers showed two stages of thermal decomposition temperature centred around 220 and 350 °C, respectively. The antimicrobial activity of the polymer sample is found to be very high and especially for gram-negative bacteria with a minimum value of 3.91 μg/mL. The in vitro drug-releasing rate is dependent on the comonomer, pH and temperature of the medium.

  13. Proteolytic release and partial characterization of human sperm-surface glycopeptides

    Directory of Open Access Journals (Sweden)

    Tortorella H.

    1997-01-01

    Full Text Available Sperm-surface glycopeptides were obtained from intact sperm membranes after proteolytic release by different enzymatic treatments such as autoproteolysis, trypsin, papain and pronase. Glycopeptides were isolated, their properties and composition were examined, and their monosaccharide and amino acid constituents were characterized. The monosaccharides identified were fucose, mannose, galactose, N-acetylglucosamine, and N-acetylgalactosamine, which form part of more than one type of oligosaccharide units. Autoproteolytic treatment mainly provided O-glycosidic type oligosaccharides, while a mixture of O- and N-glycosidic oligosaccharides was obtained in variable proportions when treated with trypsin, papain or pronase. The highest degree of peptide cleavage was obtained with pronase. Despite the higher yields reached with trypsin, these glycopeptides contain the lowest percentage of oligosaccharide chains. Proteolytic treatment provides a simple, rapid procedure for the isolation of glycopeptides from the sperm surface

  14. Assessment of trace ground-water contaminants release from south Texas in-situ uranium solution-mining sites

    Energy Technology Data Exchange (ETDEWEB)

    Kidwell, J.R.; Humenick, M.J.

    1981-01-01

    The future of uranium solution mining in south Texas depends heavily on the industry's ability to restore production zone ground water to acceptable standards. This study investigated the extent of trace contaminant solubilization during mining and subsequent restoration attempts, first through a literature search centered on uranium control mechanisms, and then by laboratory experiments simulating the mining process. The literature search indicated the complexity of the situation. The number of possible interactions between indigenous elements and materials pointed on the site specificity of the problem. The column studies evaluated three different production area ores. Uranium, molybdenum, arsenic, vanadium, and selenium were analyzed in column effluents. After simulated mining operations were completed, uranium was found to be the most persistent trace element. However, subsequent ground water flushing of the columns could restore in-situ water to EPA recommended drinking water concentrations. Limited data indicated that ground water flowing through mined areas may solubilize molybdenum present in down gradient areas adjacent to the production zone due to increased oxidation potential of ground water if adequate restoration procedures are not followed.

  15. Regaining the Moral High Ground on Gitmo...is there a Basis for released Guantanamo Detainees to Receive Reparations?

    Science.gov (United States)

    2009-12-11

    or 53 the Taliban.14 This action and the opening of Guantanamo Bay Naval Base detention facility served to mark the beginning for a new genre of...life of victims or on the experiences of horror .31 Any reparation program for released detainees would be well served to head thi 1Naomi Roht

  16. Characterization of Ground Displacement Sources from Variational Bayesian Independent Component Analysis of Space Geodetic Time Series

    Science.gov (United States)

    Gualandi, Adriano; Serpelloni, Enrico; Elina Belardinelli, Maria; Bonafede, Maurizio; Pezzo, Giuseppe; Tolomei, Cristiano

    2015-04-01

    A critical point in the analysis of ground displacement time series, as those measured by modern space geodetic techniques (primarly continuous GPS/GNSS and InSAR) is the development of data driven methods that allow to discern and characterize the different sources that generate the observed displacements. A widely used multivariate statistical technique is the Principal Component Analysis (PCA), which allows to reduce the dimensionality of the data space maintaining most of the variance of the dataset explained. It reproduces the original data using a limited number of Principal Components, but it also shows some deficiencies, since PCA does not perform well in finding the solution to the so-called Blind Source Separation (BSS) problem. The recovering and separation of the different sources that generate the observed ground deformation is a fundamental task in order to provide a physical meaning to the possible different sources. PCA fails in the BSS problem since it looks for a new Euclidean space where the projected data are uncorrelated. Usually, the uncorrelation condition is not strong enough and it has been proven that the BSS problem can be tackled imposing on the components to be independent. The Independent Component Analysis (ICA) is, in fact, another popular technique adopted to approach this problem, and it can be used in all those fields where PCA is also applied. An ICA approach enables us to explain the displacement time series imposing a fewer number of constraints on the model, and to reveal anomalies in the data such as transient deformation signals. However, the independence condition is not easy to impose, and it is often necessary to introduce some approximations. To work around this problem, we use a variational bayesian ICA (vbICA) method, which models the probability density function (pdf) of each source signal using a mix of Gaussian distributions. This technique allows for more flexibility in the description of the pdf of the sources

  17. Combining ground penetrating radar and electromagnetic induction for industrial site characterization

    Science.gov (United States)

    Van De Vijver, Ellen; Van Meirvenne, Marc; Saey, Timothy; De Smedt, Philippe; Delefortrie, Samuël; Seuntjens, Piet

    2014-05-01

    Industrial sites pose specific challenges to the conventional way of characterizing soil and groundwater properties through borehole drilling and well monitoring. The subsurface of old industrial sites typically exhibits a large heterogeneity resulting from various anthropogenic interventions, such as the dumping of construction and demolition debris and industrial waste. Also larger buried structures such as foundations, utility infrastructure and underground storage tanks are frequently present. Spills and leaks from industrial activities and leaching of buried waste may have caused additional soil and groundwater contamination. Trying to characterize such a spatially heterogeneous medium with a limited number of localized observations is often problematic. The deployment of mobile proximal soil sensors may be a useful tool to fill up the gaps in between the conventional observations, as these enable measuring soil properties in a non-destructive way. However, because the output of most soil sensors is affected by more than one soil property, the application of only one sensor is generally insufficient to discriminate between all contributing factors. To test a multi-sensor approach, we selected a study area which was part of a former manufactured gas plant site located in one of the seaport areas of Belgium. It has a surface area of 3400 m² and was the location of a phosphate production unit that was demolished at the end of the 1980s. Considering the long and complex history of the site we expected to find a typical "industrial" soil. Furthermore, the studied area was located between buildings of the present industry, entailing additional practical challenges such as the presence of active utilities and aboveground obstacles. The area was surveyed using two proximal soil sensors based on two different geophysical methods: ground penetrating radar (GPR), to image contrasts in dielectric permittivity, and electromagnetic induction (EMI), to measure the apparent

  18. Nitric oxide-releasing nanoparticles: synthesis, characterization, and cytotoxicity to tumorigenic cells

    Science.gov (United States)

    Pelegrino, Milena T.; Silva, Letícia C.; Watashi, Carolina M.; Haddad, Paula S.; Rodrigues, Tiago; Seabra, Amedea B.

    2017-02-01

    Nitric oxide (NO) is involved in several biological processes, including toxicity against tumor cells. The aim of this study was to synthesize, characterize, and evaluate the cytotoxicity of NO-releasing chitosan nanoparticles. A thiol-containing molecule, mercaptosuccinic acid (MSA), was encapsulated (encapsulation efficiency of 99%) in chitosan/sodium tripolyphosphate nanoparticles (CS NPs). The obtained nanoparticles showed an average hydrodynamic size of 108.40 ± 0.96 nm and polydispersity index of 0.26 ± 0.01. MSA-CS NPs were nitrosated leading to S-nitroso-MSA-CS NPs, which act as NO donor. The cytotoxicity of CS NPs, MSA-CS NPs, and S-nitroso-MSA-CS NPs were evaluated in several tumor cells, including human hepatocellular carcinoma (HepG2), mouse melanoma (B16F10), and human chronic myeloid leukemia (K562) cell lines and Lucena-1, a vincristine-resistant K562 cell line. Both CS NPs and MSA-CS NPs did not cause toxic effects in these cells, whereas S-nitroso-MSA-CS NPs caused potent cytotoxic effects in all the tested tumor cell lines. The half-maximal inhibitory concentration values of S-nitroso-MSA-CS NPs were 19.7, 10.5, 22.8, and 27.8 μg·mL-1 for HepG2, B16F10, K562, and Lucena-1 cells, respectively. In contrast, S-nitroso-MSA-CS NPs exhibited lower cytotoxic to non-tumorigenic melanocytes (Melan-A) when compared with melanoma B16F10. Therefore, the results highlight the potential use of NO-releasing CS NPs in antitumor chemotherapy.

  19. Characterization and Monitoring of Natural Attenuation of Chlorinated Solvents in Ground Water: A Systems Approach

    Science.gov (United States)

    Cutshall, N. H.; Gilmore, T.; Looney, B. B.; Vangelas, K. M.; Adams, K. M.; Sink, C. H.

    2006-05-01

    Like many US industries and businesses, the Department of Energy (DOE) is responsible for remediation and restoration of soils and ground water contaminated with chlorinated ethenes. Monitored Natural Attenuation (MNA) is an attractive remediation approach and is probably the universal end-stage technology for removing such contamination. Since 2003 we have carried out a multifaceted program at the Savannah River Site designed to advance the state of the art for MNA of chlorinated ethenes in soils and groundwater. Three lines of effort were originally planned: 1) Improving the fundamental science for MNA, 2) Promoting better characterization and monitoring (CM) techniques, and 3) Advancing the regulatory aspects of MNA management. A fourth line, developing enhanced attenuation methods based on sustainable natural processes, was added in order to deal with sites where the initial natural attenuation capacity cannot offset contaminant loading rates. These four lines have been pursued in an integrated and mutually supportive fashion. Many DOE site-cleanup program managers view CM as major expenses, especially for natural attenuation where measuring attenuation is complex and the most critical attenuation mechanisms cannot be determined directly. We have reviewed new and developing approaches to CM for potential application in support of natural attenuation of chlorinated hydrocarbons in ground water at DOE sites (Gilmore, Tyler, et al., 2006 WSRC-TR- 2005-00199). Although our project is focused on chlorinated ethenes, many of the concepts and strategies are also applicable to a wider range of contaminants including radionuclides and metals. The greatest savings in CM are likely to come from new management approaches. New approaches can be based, for example, on conceptual models of attenuation capacity, the ability of a formation to reduce risks caused by contaminants. Using the mass balance concept as a guide, the integrated mass flux of contaminant is compared to

  20. Characterization of Preferential Ground-Water Seepage From a Chlorinated Hydrocarbon-Contaminated Aquifer to West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 2002-04

    Science.gov (United States)

    Majcher, Emily H.; Phelan, Daniel J.; Lorah, Michelle M.; McGinty, Angela L.

    2007-01-01

    Wetlands act as natural transition zones between ground water and surface water, characterized by the complex interdependency of hydrology, chemical and physical properties, and biotic effects. Although field and laboratory demonstrations have shown efficient natural attenuation processes in the non-seep wetland areas and stream bottom sediments of West Branch Canal Creek, chlorinated volatile organic compounds are present in a freshwater tidal creek at Aberdeen Proving Ground, Maryland. Volatile organic compound concentrations in surface water indicate that in some areas of the wetland, preferential flow paths or seeps allow transport of organic compounds from the contaminated sand aquifer to the overlying surface water without undergoing natural attenuation. From 2002 through 2004, the U.S. Geological Survey, in cooperation with the Environmental Conservation and Restoration Division of the U.S. Army Garrison, Aberdeen Proving Ground, characterized preferential ground-water seepage as part of an ongoing investigation of contaminant distribution and natural attenuation processes in wetlands at this site. Seep areas were discrete and spatially consistent during thermal infrared surveys in 2002, 2003, and 2004 throughout West Branch Canal Creek wetlands. In these seep areas, temperature measurements in shallow pore water and sediment more closely resembled those in ground water than those in nearby surface water. Generally, pore water in seep areas contaminated with chlorinated volatile organic compounds had lower methane and greater volatile organic compound concentrations than pore water in non-seep wetland sediments. The volatile organic compounds detected in shallow pore water in seeps were spatially similar to the dominant volatile organic compounds in the underlying Canal Creek aquifer, with both parent and anaerobic daughter compounds detected. Seep locations characterized as focused seeps contained the highest concentrations of chlorinated parent compounds

  1. Characterizing Olive Grove Canopies by Means of Ground-Based Hemispherical Photography and Spaceborne RADAR Data

    Directory of Open Access Journals (Sweden)

    Carmen Morillo

    2011-07-01

    Full Text Available One of the main strengths of active microwave remote sensing, in relation to frequency, is its capacity to penetrate vegetation canopies and reach the ground surface, so that information can be drawn about the vegetation and hydrological properties of the soil surface. All this information is gathered in the so called backscattering coefficient (s0. The subject of this research have been olive groves canopies, where which types of canopy biophysical variables can be derived by a specific optical sensor and then integrated into microwave scattering models has been investigated. This has been undertaken by means of hemispherical photographs and gap fraction procedures. Then, variables such as effective and true Leaf Area Indices have been estimated. Then, in order to characterize this kind of vegetation canopy, two models based on Radiative Transfer theory have been applied and analyzed. First, a generalized two layer geometry model made up of homogeneous layers of soil and vegetation has been considered. Then, a modified version of the Xu and Steven Water Cloud Model has been assessed integrating the canopy biophysical variables derived by the suggested optical procedure. The backscattering coefficients at various polarized channels have been acquired from RADARSAT 2 (C-band, with 38.5° incidence angle at the scene center. For the soil simulation, the best results have been reached using a Dubois scattering model and the VV polarized channel (r2 = 0.88. In turn, when effective LAI (LAIeff has been taken into account, the parameters of the scattering canopy model are better estimated (r2 = 0.89. Additionally, an inversion procedure of the vegetation microwave model with the adjusted parameters has been undertaken, where the biophysical values of the canopy retrieved by this methodology fit properly with field measured values.

  2. Characterization approaches using ground-penetrating radar and hydrological measurements in variably saturated porous media

    Science.gov (United States)

    Kowalsky, Michael Brendan

    Modeling the flow of water or the transport of contaminants through the subsurface requires the characterization of soil properties including permeability, porosity, and water retention. Such hydrological parameters are commonly heterogeneous, and uncertainty in their spatial distributions makes it difficult to construct hydrological models from only point measurements, which are commonly limited since their collection is expensive, time consuming and invasive. The application of geophysical methods offers a promising alternative for inferring hydrological properties in the subsurface. The focus of this dissertation is on a variety of applications of ground penetrating radar (GPR), a geophysical method that provides data non-invasively (or minimally invasively) with high spatial resolution and at low cost. While GPR data are increasingly used in shallow subsurface characterization, relations between such data and subsurface flow processes are poorly understood. The research presented in this dissertation stems from the need for (1) a better understanding of GPR data in relation to non-uniform and transient distributions of pore water, and (2) an approach relating GPR attributes, possibly in combination with additional data types, to hydrological parameters. An overview of GPR methods is given, including reviews of previous applications and of techniques for simulating GPR measurements, and is followed by a series of case studies. Comparison of real field data and simulations performed with an outcrop-derived model under various states of water saturation shows that the detectability of some sedimentary units depends on in-situ moisture conditions. Then, the simultaneous simulation of GPR surveys and transient flow shows that time-lapsed measurements offer information that might be useful for inferring hydrological parameter distributions in the vadose zone. An inverse technique is then presented which allows for the estimation of actual flow parameters using GPR

  3. Anaerobic sediment potential acidification and metal release risk assessment by chemical characterization and batch resuspension experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nanno, M.P. di [Univ. de San Martin, Buenos Aires (Argentina). Escuela de Ciencia y Technologia; Curutchet, G. [Univ. de San Martin, Buenos Aires (Argentina). Escuela de Ciencia y Technologia; CONICET, Buenos Aires (Argentina); Ratto, S. [Univ. de Buenos Aires (Argentina). Catedra de Edafologia

    2007-06-15

    Background, Aim and Scope: Sediments act as a sink for toxic substances (heavy metals, organic pollutants) and, consequently, dredged materials often contain pollutants which are above safe limits. In polluted anaerobic sediments, the presence of sulphides and redox potential changes creates a favorable condition for sulphide oxidation to sulphate, resulting in potential toxic metal release. The oxidation reaction is catalyzed by several microorganisms. Some clean up measures, such as dredging, can initiate the process. The aim of the present work is to assess the acidification and metal release risk in the event of sediment dredging and also to compare two different acid base account techniques with the resuspension results. The oxidation mechanism by means of inoculation with an Acidithiobacillus ferrooxidans strain was also evaluated. Materials and Methods: The sediments were chemically characterized (pH; organic oxidizable carbon; acid volatile sulphides; total sulphur; moisture; Cr, Cu and Zn aqua regia contents). A metal sequential extraction procedure (Community Bureau of Reference, BCR technique) was applied to calculate the Acid Producing Potential (APP) and Acid Consuming Capacity (ACC) of the sediment samples through Fe, Ca{sup 2+} and SO{sub 4}{sup 2-} measurements. The acid base account was also performed by the Sobek methodology (Acid producing potential - AP - calculated with total sulphur and neutralization potential - NP - by titration of the remaining acid after a reaction period with the sample). Fresh sediments were placed in agitated shake flasks and samples were taken at different times to evaluate pH, SO{sub 4}{sup 2-} and Cr, Cu, Zn and Fe{sup 2+} concentration. Some of the systems were inoculated with an Acidithiobacillus ferrooxidans strain to assess the biological catalysis on sulphide oxidation. Results: Sediment chemical characterization showed high organic matter content (5.4-10.6%), total sulphur (0.36-0.86%) and equivalent CaCO{sub 3

  4. Controlled release formulations of Atrazine and Mesotrione: characterization and sorption on soils

    Science.gov (United States)

    Pinheiro Dick, D.; Gomes de Ávila, L.; Benvenuti Leite, S.; Raffin Pohlmann, A.

    2009-04-01

    Atrazine is a widely used herbicide on corn and sugar cane plantations, which, along with soybeans, are the most productive crops in Brazil and are responsible for 36.5% of the annual national consumption of herbicides. Mesotrione is a new herbicide registered in the last years used for controlling weeds in corn plantations as a tentative substitution for atrazine. After its application in the field, reactions between the herbicide and chemical groups from the soil matrix surface occur, and this complexed form remains in the soil, representing a potential source for environmental contamination and also affecting its agronomic efficiency. Therefore, the application of herbicides associated to carrier systems may represent an alternative to mitigate the environmental impact caused by their intense usage, considering that the interaction between the soil matrix and the xenobiotic is reduced, and thus, diminishes the recommended dosis and reduces the environmental pollution. The objectives of this study are to evaluate the chemical and morphological characteristics of controlled release formulations of atrazine (ATZ) and of mesotrione (MES) and to investigate their sorptive behavior in three representative Brazilian soils. To assess the feasibility of using these associated systems, four formulations (SGATZ) containing different concentrations of atrazine and four formulations (SGMES) containing different levels of mesotrione (MES) were synthesized by the sol-gel method (SG), using tetraetil-ortho-silicate as precursor and NaF as catalyst. The formulations were characterized by elemental analysis, adsorption and desorption isotherms of nitrogen, thermal analysis (DSC), scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). For comparison, samples of pure xerogel (SG), commercial MES (Callisto-Syngenta), pure ATZ (99% of active principle, Milênia), granulated ATZ (Gesaprim GrDA Syngenta) and dried commercial ATZ (Nortox 500 SC) were analyzed. The

  5. Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

    Directory of Open Access Journals (Sweden)

    Tales Tiecher

    2014-10-01

    Full Text Available Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR spectroscopy to assess the P forms in three different dry manure types (i.e. poultry, cattle and swine manure. All three methods showed that the P forms in poultry, cattle and swine dry manures are mostly inorganic and highly bioavailable. The estimated P pools showed that organic and recalcitrant P forms were negligible and highly dependent on the Ca:P ratio in manures. The results obtained here showed that the extraction of P with these three different methods allows a better understanding and complete characterization of the P pools present in the manures.

  6. Advanced characterization of dissolved organic matter released by bloom-forming marine algae

    KAUST Repository

    Rehman, Zahid Ur

    2017-06-01

    Algal organic matter (AOM), produced by marine phytoplankton during bloom periods, may adversely affect the performance of membrane processes in seawater desalination. The polysaccharide fraction of AOM has been related to (bio)fouling in micro-filtration and ultrafiltration, and reverse osmosis membranes. However, so far, the chemical structure of the polysaccharides released by bloom-forming algae is not well understood. In this study, dissolved fraction of AOM produced by three algal species (Chaetoceros affinis, Nitzschia epithemoides and Hymenomonas spp.) was characterized using liquid chromatography–organic carbon detection (LC-OCD) and fluorescence spectroscopy. Chemical structure of polysaccharides isolated from the AOM solutions at stationary phase was analyzed using proton nuclear magnetic resonance (H-NMR). The results showed that production and composition of dissolved AOM varied depending on algal species and their growth stage. AOM was mainly composed of biopolymers (BP; i.e., polysaccharides and proteins [PN]), but some refractory substances were also present.H-NMR spectra confirmed the predominance of carbohydrates in all samples. Furthermore, similar fingerprints were observed for polysaccharides of two diatom species, which differed considerably from that of coccolithophores. Based on the findings of this study,H-NMR could be used as a method for analyzing chemical profiles of algal polysaccharides to enhance the understanding of their impact on membrane fouling.

  7. Oral controlled release drug delivery system and Characterization of oral tablets; A review

    Directory of Open Access Journals (Sweden)

    Muhammad Zaman

    2016-01-01

    Full Text Available Oral route of drug administration is considered as the safest and easiest route of drug administration. Control release drug delivery system is the emerging trend in the pharmaceuticals and the oral route is most suitable for such kind of drug delivery system. Oral route is more convenient for It all age group including both pediatric and geriatrics. There are various systems which are adopted to deliver drug in a controlled manner to different target sites through oral route. It includes diffusion controlled drug delivery systems; dissolution controlled drug delivery systems, osmotically controlled drug delivery systems, ion-exchange controlled drug delivery systems, hydrodynamically balanced systems, multi-Particulate drug delivery systems and microencapsulated drug delivery system. The systems are formulated using different natural, semi-synthetic and synthetic polymers. The purpose of the review is to provide information about the orally controlled drug delivery system, polymers which are used to formulate these systems and characterizations of one of the most convenient dosage form which is the tablets. 

  8. Ground-state characterizations of systems predicted to exhibit L11 or L13 crystal structures

    Science.gov (United States)

    Nelson, Lance J.; Hart, Gus L. W.; Curtarolo, Stefano

    2012-02-01

    Despite their geometric simplicity, the crystal structures L11 (CuPt) and L13 (CdPt3) do not appear as ground states experimentally, except in Cu-Pt. We investigate the possibility that these phases are ground states in other binary intermetallic systems, but overlooked experimentally. Via the synergy between high-throughput and cluster-expansion computational methods, we conduct a thorough search for systems that may exhibit these phases and calculate order-disorder transition temperatures when they are predicted. High-throughput calculations predict L11 ground states in the systems Ag-Pd, Ag-Pt, Cu-Pt, Pd-Pt, Li-Pd, Li-Pt, and L13 ground states in the systems Cd-Pt, Cu-Pt, Pd-Pt, Li-Pd, Li-Pt. Cluster expansions confirm the appearance of these ground states in some cases. In the other cases, cluster expansion predicts unsuspected derivative superstructures as ground states. The order-disorder transition temperatures for all L11/L13 ground states were found to be sufficiently high that their physical manifestation may be possible.

  9. Geochemical characterization of shallow ground water in the Eutaw aquifer, Montgomery, Alabama

    Science.gov (United States)

    Robinson, J.L.; Journey, C.A.

    2004-01-01

    Ground water samples were collected from 30 wells located in, or directly down gradient from, recharge areas of the Eutaw aquifer in Montgomery, Alabama. The major ion content of the water evolves from calcium-sodium-chloride- dominated type in the recharge area to calcium-bicarbonate-dominated type in the confined portion of the aquifer. Ground water in the recharge area was undersaturated with respect to aluminosilicate and carbonate minerals. Ground water in the confined portion of the aquifer was at equilibrium levels for calcite and potassium feldspar. Dissolved oxygen and nitrite-plus-nitrate concentrations decreased as ground water age increased; pH, iron, and sulfate concentrations increased as ground water age increased. Aluminum, copper, and zinc concentrations decreased as ground water age and pH increased. These relations indicate that nitrate, aluminum, copper, and zinc are removed from solution as water moves from recharge areas to the confined areas of the Eutaw aquifer. The natural evolution of ground water quality, which typically increases the pH and decreases the dissolved oxygen content, may be an important limiting factor to the migration of nitrogen based compounds and metals.

  10. Characterization of porosity in a 19th century painting ground by synchrotron radiation X-ray tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gervais, Claire [Swiss Institute for Art Research (SIK-ISEA), Zuerich (Switzerland); Bern University of the Arts, Bern (Switzerland); Boon, Jaap J. [Swiss Institute for Art Research (SIK-ISEA), Zuerich (Switzerland); JAAP Enterprise for MOLART Advice, Amsterdam (Netherlands); Marone, Federica [Paul Scherrer Institute, Swiss Light Source (SLS), Villigen (Switzerland); Ferreira, Ester S.B. [Swiss Institute for Art Research (SIK-ISEA), Zuerich (Switzerland)

    2013-04-15

    The study of the early oeuvre of the Swiss painter Cuno Amiet (1868-1961) has revealed that, up to 1907, many of his grounds were hand applied and are mainly composed of chalk, bound in protein. These grounds are not only lean and absorbent, but also, as Synchrotron radiation X-ray microtomography has shown, porous. Our approach to the characterization of pore structure and quantity, their connectivity, and homogeneity is based on image segmentation and application of a clustering algorithm to high-resolution X-ray tomographic data. The issues associated with the segmentation of the different components of a ground sample based on X-ray imaging data are discussed. The approach applied to a sample taken from ''Portrait of Max Leu'' (1899) by Amiet revealed the presence of three sublayers within the ground with distinct porosity features, which had not been observed optically in cross-section. The upper and lower layers are highly porous with important connectivity and thus prone to water uptake/storage. The middle layer however shows low and nonconnected porosity at the resolution level of the X-ray tomography images, so that few direct water absorption paths through the entire sample exist. The potential of the method to characterize porosity and to understand moisture-related issues in paint layer degradation are discussed. (orig.)

  11. Double-walled microspheres for the sustained release of a highly water soluble drug: characterization and irradiation studies.

    Science.gov (United States)

    Lee, Teng Huar; Wang, Jianjun; Wang, Chi-Hwa

    2002-10-30

    Composite double-walled microspheres with biodegradable poly(L-lactic acid) (PLLA) shells and poly(D,L-lactic-co-glycolic acid) (PLGA) cores were fabricated with highly water-soluble etanidazole entrapped within the core as solid crystals. This paper discusses the characterization, in vitro release and the effects of irradiation on this class of microsphere. Through the variation of polymer mass ratios, predictable shell and core dimensions could be fabricated and used to regulate the release rates. A direct and simple method was devised to determine the composition of the shell and core polymer based on the different solubilities of the polymer pair in ethyl acetate. A distribution theory based on solubility parameter explains why highly hydrophilic etanidazole has the tendency to be distributed consistently to the more hydrophilic polymer. Release profiles for normal double-walled samples have about 80% of drug released over 10 days after the initial time lag, while for irradiated double-walled samples, the sustained release lasted for more than 3 weeks. Although sustained release was short of the desired 6-8 weeks required for therapy, a low initial burst of less than 5% and time lags that can be manipulated, allows for administration of these microspheres together with traditional ones to generate pulsatile or new type of releases. The effects of irradiation were also investigated to determine the suitability of these double-walled microspheres as delivery devices to be used in conjunction with radiotherapy. Typical therapeutic dosage of 50 Gy was found to be too mild to have noticeable effects on the polymer and its release profiles, while, sterilization dosages of 25 kGy, lowered the glass transition temperatures and crystalline melting point, indirectly indicating a decrease in molecular weight. This accelerated degradation of the polymer, hence releasing the drug.

  12. Characterization and in vitro release studies of tetracycline and rolitetracycline imobilized on anionic collagen membranes

    Directory of Open Access Journals (Sweden)

    Gilberto Goissis

    2009-03-01

    Full Text Available This work reports the covalent immobilization of tetracycline and rolitetracycline over anionic collagen membranes and the drug release studies as an effort to develop a two stage drug release based on diffusion (fast release and on the rate of membrane biodegradation (slow release. Independent from casting conditions antibiotics incorporated by dispersion were released in the range from 80 to 100% within 7 hours in concentrations significantly higher than those described for the prevention of bacterial growth. Antibiotic release within this period was predominantly diffusion controlled. Covalent immobilization by a modified azide procedure occurred with preservation of collagen structure independently from pH of casting and reaction conditions. Its expected that anionic collagen membranes with dispersed and covalently bound rolitetracycline or tetracycline, in association with conventional therapy, may significantly reduce membrane induced infections observed post-implantation, one of the major problem associated with periodontal ligaments reconstruction by the Guided Tissue Regeneration procedure.

  13. Formulation and characterization of modified release tablets containing isoniazid using swellable polymers.

    Science.gov (United States)

    Akhtar, M F; Rabbani, M; Sharif, A; Akhtar, B; Saleem, A; Murtaza, G

    2011-01-01

    The aim of this work was to develop swellable modified release (MR) isoniazid tablets using different combinations of polyvinyl acetate (PVAc) and sodium-carboxymethylcellulose (Na-CMC). Granules were prepared by moist granulation technique and then compressed into tablets. In vitro release studies for 12 hr were carried out in dissolution media of varying pH i.e. pH 1.2, 4.5, 7.0 and 7.5. Tablets of all formulations were found to be of good physical quality with respect to appearance (width and thickness), content uniformity, hardness, weight variation and friability. In vitro release data showed that increasing total polymer content resulted in more retarding effect. Formulation with 35% polymer content exhibited zero order release profile and it released 35% of the drug in first hr, later on, controlled drug release was observed upto the 12(th) hour. Formulations with PVAc to Na-CMC ratio 20:80 exhibited zero order release pattern at levels of studied concentrations, which suggested that this combination can be used to formulate zero order release tablets of water soluble drugs like isoniazid. Korsmeyer-Peppas modeling of drug release showed that non-Fickian transport is the primary mechanism of isoniazid release from PVAc and Na-CMC based tablets. The value of mean dissolution time decreased with the increase in the release rate of drug clearly showing the retarding behavior of the swellable polymers. The application of a mixture of PVAc to Na-CMC in a specific ratio may be feasible to formulate zero order release tablets of water soluble drugs like isoniazid.

  14. Characterization and In Vitro Sustained Release of Silibinin from pH Responsive Carbon Nanotube-Based Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Julia M. Tan

    2014-01-01

    Full Text Available The objective of the present study was to develop and characterize an in vitro sustained release formulation of silibinin (SB using commercially available carboxylated multiwalled carbon nanotubes (COOH-MWCNTs and to investigate cytotoxicity action of the synthesized nanohybrid (SB-MWCNTs. The resulting nanohybrid was characterized with Fourier transform infrared (FTIR, Raman spectroscopy, thermogravimetric analysis (TGA, ultraviolet-visible spectrophotometry (UV-Vis, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. FTIR, Raman spectroscopy, and TGA analysis confirmed the adsorption of SB molecules to the COOH-MWCNTs. The release of SB from the COOH-MWCNTs nanocarrier was found to be sustained and pH-dependent. The maximum percentage release of SB from the nanocarrier reached approximately 96.6% and 43.1% within 1000 minutes when exposed to pH 7.4 and pH 4.8 solutions, respectively. It was observed that the release of kinetic behaviour of SB from the MWCNTs nanocarrier conformed well to pseudo-second order kinetic model. The obtained MTT result showed that the SB-MWCNTs exhibited enhanced cytotoxicity to human cancer cell lines in comparison with free SB at lower concentrations. These results suggest that SB-MWCNTs nanohybrid may be a promising nanodrug delivery system with sustained release property for the treatment of cancers.

  15. Soft Soil Site Characterization on the Coast of Yantai and Its Effect on Ground Motion Parameters

    Institute of Scientific and Technical Information of China (English)

    Lü Yuejun; Tang Rongyu; Peng Yanju

    2005-01-01

    According to the Chinese GB50011-2001 code and the recommended provisions of FEMANEHRP and EUROCODE 8, by using shear wave velocity and borehole data, the site classification is evaluated for a typical soft soil site on the Yantai seacoast. The site seismic ground motion effect is analyzed and the influence of the coastal soil on design ground motion parameters is discussed. The results show that the brief site classification can not represent the real conditions of a soft soil site; the soft soil on the coast has a remarkable impact on the magnitude and spectrum of ground motion acceleration. The magnification on peak acceleration is bigger, however, due to the nonlinear deformation of the soil. The magnification is reduced nonlinearly with the increase of input ground motion; the spectrum is broadened and the characteristic period elongated on the soft soil site.

  16. Soil moisture characterization of the Valencia anchor station. Ground, aircraft measurements and simulations

    DEFF Research Database (Denmark)

    Lopez-Baeza, E; Antolin, M C; Balling, Jan E.

    2009-01-01

    , soil type, lithology, geology, elevation, slope and vegetation cover conditions. Complementary to the ground measurements, flight operations were performed over this control area using the Helsinki University of Technology TKK Short Skyvan research aircraft which contained onboard a payload constituted...

  17. Sandwich-like mesoporous silica flakes for anticancer drug transport-Synthesis, characterization and kinetics release study.

    Science.gov (United States)

    Mijowska, E; Cendrowski, K; Barylak, M; Konicki, W

    2015-12-01

    In this paper, we present the technology of synthesis, characterization and release kinetics of anticancer drug molecules from sandwich-like mesoporous silica nanoflakes. Mesoporous silica nanoflakes are a very attractive material due to their versatility, low cytotoxicity, large surface area, high pore volume and unique feature of containing parallel pores openon both sides. Nanosilica flakes were prepared through the formation of a mesoporous silica layer on a graphene oxide surface. After graphene oxide removal, the silica nanostructures were filled by an anticancer drug-methotrexate. Release kinetics studies were performed in different temperatures, imitating the conditions in living organisms. Release data was analyzed using the zero-order model, first-order model, Higuchi model and Korsmeyer-Peppas model. The optical properties of samples, and the kinetics of drug release from the nanostructure, were examined by UV-vis spectrophotometer. Data obtained from long term studies showed that the system can serve as an anticancer drug carrier system, since a significant amount of methotrexate was loaded to the material and released. The mechanism of MTX release from mesoporous silica nanoflakes appeared to be a parallel processes of diffusion through water-filled mesopores and degradation of the mSiO2 matrix. Physical and chemical characterization was undertaken by transmission electron microscopy (TEM) and X-ray dispersion spectroscopy (EDX). The specific surface area of the samples was measured through the adsorption of N2 isotherm, interpreted with the Brunauer-Emmett-Teller model (BET). TGA and UV-vis analyses were conducted in order to estimate the amount of the released drug.

  18. Re-usable quick-release interconnect for characterization of microfluidic systems

    Science.gov (United States)

    Bhagat, Ali Asgar S.; Jothimuthu, Preetha; Pais, Andrea; Papautsky, Ian

    2007-01-01

    In this work, we present a simple method for establishing re-usable quick-release compression-based fluidic connections for characterization of microfluidic systems. Our interconnect scheme uses O-rings to form a compression seal against the upper surface of the microfluidic device and around the inlet/outlet tubing, thus establishing connections to the macroworld and preventing any leaks at the ports. With this approach, fabrication is inexpensive and easy, not requiring time-consuming or specialized fabrication procedures. The connections to the real world can be established and removed numerous times without damaging the microfluidic device, and since the approach is adhesive-free there is no danger of microchannel blockage. The demonstrated interconnect is also flexible enough to permit tube bending parallel to the device and makes it possible to place input ports close together to minimize dimensions of complex microfluidic systems. In leakage tests, the interconnect was measured to withstand pressures up to 1.7 MPa, which is enough for most microfluidic applications, and probably nanofluidic applications. This interconnect makes connecting inlets and outlets faster and easier, saving hours of processing time. It can be quickly and easily reconfigured to match device port positions, and is compatible with microfluidic systems fabricated in polymer, plastic, glass or silicon. Further, the flexible nature of the developed compression-based interconnect, both with regard to tubing flexibility and the ability to re-use numerous times, makes it ideal for rapid prototyping of research systems and potentially for quality control in large-scale production.

  19. Physicochemical characterization of liposomes after ultrasound exposure - mechanisms of drug release

    DEFF Research Database (Denmark)

    Evjen, Tove J; Hupfeld, Stefan; Barnert, Sabine

    2013-01-01

    Ultrasound is investigated as a novel drug delivery tool within cancer therapy. Non-thermal ultrasound treatment of solid tumours post i.v.-injection of drug-carrying liposomes may induce local drug release from the carrier followed by enhanced intracellular drug uptake. Recently, ultrasound......-mediated drug release of liposomes (sonosensitivity) was shown to strongly depend on liposome membrane composition. In the current study the ultrasound-mediated drug release mechanism of liposomes was investigated. The results showed that differences in ultrasound drug release kinetics obtained for different...... liposomal compositions were caused by distinctive release mechanisms of the carriers. Two types of liposomes composed of 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) and hydrogenated soy L-α-phosphatidylcholine (HSPC) as main lipids, respectively, were recently shown to vary in sonosensitivity...

  20. Implementing ground surface deformation tools to characterize field-scale properties of a fractured aquifer during a short hydraulic test

    Science.gov (United States)

    Schuite, Jonathan; Longuevergne, Laurent; Bour, Olivier; Boudin, Frédérick; Durand, Stéphane

    2016-04-01

    In naturally fractured reservoirs, fluid flow is governed by the structural and hydromechanical properties of fracture networks or conductive fault zones. In order to ensure a sustained exploitation of resources or to assess the safety of underground storage, it is necessary to evaluate these properties. As they generally form highly heterogeneous and anisotropic reservoirs, fractured media may be well characterized by means of several complementary experimental methods or sounding techniques. In this framework, the observation of ground deformation has been proved useful to gain insight of a fractured reservoir's geometry and hydraulic properties. Commonly, large conductive structures like faults can be studied from surface deformation from satellite methods at monthly time scales, whereas meter scale fractures have to be examined under short-term in situ experiments using high accuracy intruments like tiltmeters or extensometers installed in boreholes or at the ground's surface. To the best of our knowledge, the feasability of a field scale (~ 100 m) characterization of a fractured reservoir with geodetic tools in a short term experiment has not yet been addressed. In the present study, we implement two complementary ground surface geodetic tools, namely tiltmetry and optical leveling, to monitor the deformation induced by a hydraulic recovery test at the Ploemeur hydrological observatory (France). Employing a simple purely elastic modeling approach, we show that the joint use of time constraining data (tilt) and spatially constraining data (vertical displacement) makes it possible to evaluate the geometry (dip, root depth and lateral extent) and the storativity of a hydraulically active fault zone, in good agreement with previous studies. Hence we demonstrate that the adequate use of two complementary ground surface deformation methods offer a rich insight of large conductive structure's properties using a single short term hydraulic load. Ground surface

  1. Potato starch-blended alginate beads for prolonged release of tolbutamide: Development by statistical optimization and in vitro characterization

    Directory of Open Access Journals (Sweden)

    Jadupati Malakar

    2013-01-01

    Full Text Available The work investigates the development and optimization of novel beads of potato starch-alginate blend containing tolbutamide by ionotropic gelation using 3 2 factorial design. The optimized beads exhibited 85.57 ± 3.24% drug encapsulation efficiency and 50.42 ± 2.18% drug release after 8 h. The in vitro drug release followed controlled-release (zero-order pattern with super case-II transport mechanism over 8 h. The swelling and degradation of the optimized beads were influenced by pH of test mediums. These were also characterized by SEM and FTIR analysis. These newly developed beads are suitable for controlled delivery of tolbutamide for prolonged period.

  2. Preparation, Characterization and Release of Urea from Wheat Gluten Electrospun Membranes

    Science.gov (United States)

    Castro-Enríquez, Daniela Denisse; Rodríguez-Félix, Francisco; Ramírez-Wong, Benjamín; Torres-Chávez, Patricia Isabel; Castillo-Ortega, María Mónica; Rodríguez-Félix, Dora Evelia; Armenta-Villegas, Lorena; Ledesma-Osuna, Ana Irene

    2012-01-01

    Homogeneous and thin porous membranes composed of oriented fibers were obtained from wheat gluten (WG) using the electrospinning technique. SEM micrographs showed an asymmetric structure and some porosity, which, in addition to a small thickness of 40 μm, are desirable characteristics for the membranes’ potential application in release systems. The membranes were loaded with urea to obtain pastilles. FT-IR and DSC studies confirmed the existence of interactions via hydrogen bonding between urea and WG proteins. The pastilles were studied as prolonged-released systems of urea in water. The release of urea during the first 10 min was very fast; then, the rate of release decreased as it reached equilibrium at 300 min, with a total of ≈98% urea released. TGA analysis showed that the release system obtained is thermally stable up to a temperature of 117 °C. It was concluded that a prolonged-release system of urea could be satisfactorily produced using WG fibers obtained by electrospinning for potential application in agricultural crops.

  3. Preparation, Characterization and Release of Urea from Wheat Gluten Electrospun Membranes

    Directory of Open Access Journals (Sweden)

    Ana Irene Ledesma-Osuna

    2012-12-01

    Full Text Available Homogeneous and thin porous membranes composed of oriented fibers were obtained from wheat gluten (WG using the electrospinning technique. SEM micrographs showed an asymmetric structure and some porosity, which, in addition to a small thickness of 40 mm, are desirable characteristics for the membranes’ potential application in release systems. The membranes were loaded with urea to obtain pastilles. FT-IR and DSC studies confirmed the existence of interactions via hydrogen bonding between urea and WG proteins. The pastilles were studied as prolonged-released systems of urea in water. The release of urea during the first 10 min was very fast; then, the rate of release decreased as it reached equilibrium at 300 min, with a total of »98% urea released. TGA analysis showed that the release system obtained is thermally stable up to a temperature of 117 °C. It was concluded that a prolonged-release system of urea could be satisfactorily produced using WG fibers obtained by electrospinning for potential application in agricultural crops.

  4. Preparation and Characterization of Kynurenic Acid Occluded in Sol-Gel Silica and SBA-15 Silica as Release Reservoirs

    Directory of Open Access Journals (Sweden)

    Tessy López

    2014-01-01

    Full Text Available Kynurenic acid (KYNA may have important therapeutic effects in neurological disorders; however, its use as a neuroprotective agent is restricted due to its very limited ability to cross the blood brain barrier (BBB. For this reason, we are looking for new alternatives for KYNA to reach the brain; one of them is using drug delivery systems. To obtain KYNA release reservoirs, KYNA molecules were hosted in two different silica materials. The different KYNA-silica materials were characterized by means of several physical techniques. The spectroscopic studies showed that KYNA molecules remained unchanged once hosted in silica materials. The surface area values of KYNA-silica samples were substantially lower than those for pure silica materials due to the addition of the drug. The electronic micrographs showed that the sol-gel KYNA-silica material consisted of aggregates of nanoparticles around 50 nm in size. On the other hand, the typical SBA-15 hexagonal arrangement was observed, even when hosting KYNA molecules. KYNA release profiles, carried out during approximately 300 hours, showed a first stage of fast drug release followed by a slow release phase. The experimental values fitted to the Peppas equation indicate that the release mechanism was controlled by Fickian diffusion.

  5. PEGylated PLGA Nanoparticles as Tumor Ecrosis Factor-α Receptor Blocking Peptide Carriers: Preparation,Characterization and Release in vitro

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; YANG Anshu; LI Zhuoya; XU Huibi; YANG Xiangliang

    2007-01-01

    To assess the merits of PEGylated poly (lactic-co-glycolic acid) (PEG-PLGA) nanoparticles as drug carriers for tumor necrosis factor-α receptor blocking peptide (TNFR-BP), PEG-PLGA copolymer,which could be used to prepare the stealth nanoparticles, was synthesized with methoxypolyethyleneglycol,DL-lactide and glycolide. The structure of PEG-PLGA was confirmed with 1H-NMR and FT-IR spectroscopy,and the molecular weight (MW) was determined by gel permeation chromatography. Fluorescent FITC-TNFR-BP was chosen as model protein and encapsulated within PEG-PLGA nanoparticles using the double emulsion method. Atomic force microscopy and photon correlation spectroscopy were employed to characterize the stealth nanoparticles fabricated for morphology, size with polydispersity index and zeta potential. Encapsulation efficiency (EE) and the release of FITC-TNFR-BP in nanoparticles in vitro were measured by the fluorescence measurement. The stealth nanoparticles were found to have the mean diameter less than 270 nm and zeta potential less than-20 mV. In all nanoparticle formulations, more than 45% of EE were obtained. FITC-TNFR-BP release from the PEG-PLGA nanoparticles exhibited a biphasic pattern, initial burst release and consequently sustained release. The experimental results show that PEG-PLGA nanoparticles possess the potential to develop as drug carriers for controlled release applications of TNFR-BP.

  6. Method for isolation and molecular characterization of extracellular microvesicles released from brain endothelial cells

    Directory of Open Access Journals (Sweden)

    Haqqani Arsalan S

    2013-01-01

    Full Text Available Abstract Background In addition to possessing intracellular vesicles, eukaryotic cells also produce extracellular microvesicles, ranging from 50 to 1000 nm in diameter that are released or shed into the microenvironment under physiological and pathological conditions. These membranous extracellular organelles include both exosomes (originating from internal vesicles of endosomes and ectosomes (originating from direct budding/shedding of plasma membranes. Extracellular microvesicles contain cell-specific collections of proteins, glycoproteins, lipids, nucleic acids and other molecules. These vesicles play important roles in intercellular communication by acting as carrier for essential cell-specific information to target cells. Endothelial cells in the brain form the blood–brain barrier, a specialized interface between the blood and the brain that tightly controls traffic of nutrients and macromolecules between two compartments and interacts closely with other cells forming the neurovascular unit. Therefore, brain endothelial cell extracellular microvesicles could potentially play important roles in ‘externalizing’ brain-specific biomarkers into the blood stream during pathological conditions, in transcytosis of blood-borne molecules into the brain, and in cell-cell communication within the neurovascular unit. Methods To study cell-specific molecular make-up and functions of brain endothelial cell exosomes, methods for isolation of extracellular microvesicles using mass spectrometry-compatible protocols and the characterization of their signature profiles using mass spectrometry -based proteomics were developed. Results A total of 1179 proteins were identified in the isolated extracellular microvesicles from brain endothelial cells. The microvesicles were validated by identification of almost 60 known markers, including Alix, TSG101 and the tetraspanin proteins CD81 and CD9. The surface proteins on isolated microvesicles could potentially

  7. Method for isolation and molecular characterization of extracellular microvesicles released from brain endothelial cells.

    Science.gov (United States)

    Haqqani, Arsalan S; Delaney, Christie E; Tremblay, Tammy-Lynn; Sodja, Caroline; Sandhu, Jagdeep K; Stanimirovic, Danica B

    2013-01-10

    In addition to possessing intracellular vesicles, eukaryotic cells also produce extracellular microvesicles, ranging from 50 to 1000 nm in diameter that are released or shed into the microenvironment under physiological and pathological conditions. These membranous extracellular organelles include both exosomes (originating from internal vesicles of endosomes) and ectosomes (originating from direct budding/shedding of plasma membranes). Extracellular microvesicles contain cell-specific collections of proteins, glycoproteins, lipids, nucleic acids and other molecules. These vesicles play important roles in intercellular communication by acting as carrier for essential cell-specific information to target cells. Endothelial cells in the brain form the blood-brain barrier, a specialized interface between the blood and the brain that tightly controls traffic of nutrients and macromolecules between two compartments and interacts closely with other cells forming the neurovascular unit. Therefore, brain endothelial cell extracellular microvesicles could potentially play important roles in 'externalizing' brain-specific biomarkers into the blood stream during pathological conditions, in transcytosis of blood-borne molecules into the brain, and in cell-cell communication within the neurovascular unit. To study cell-specific molecular make-up and functions of brain endothelial cell exosomes, methods for isolation of extracellular microvesicles using mass spectrometry-compatible protocols and the characterization of their signature profiles using mass spectrometry -based proteomics were developed. A total of 1179 proteins were identified in the isolated extracellular microvesicles from brain endothelial cells. The microvesicles were validated by identification of almost 60 known markers, including Alix, TSG101 and the tetraspanin proteins CD81 and CD9. The surface proteins on isolated microvesicles could potentially interact with both primary astrocytes and cortical neurons

  8. 5-Fluorouracil loaded guar gum microspheres for colon delivery:preparation, characterization and in vitro release

    Institute of Scientific and Technical Information of China (English)

    KAUSHIK Dinesh; SARDANA Satish; MISHRA DN

    2009-01-01

    The present investigation is aimed to develop a new formulation containing chemically cross-linked guar gum microspheres loaded with 5-fluorouracil for targeting colorectal cancer. The emulsification polymerization method involving the dispersion of aqueous phase of guar gum in castor oil was used to prepare spherical microspheres. Various processing parameters were studied in order to optimize the formulation. Particle size and surface morphology of the microspheres were determined using optical microscopy and scanning electron microscopy. The in vitro drug release studies performed in simulated gastric fluid (SGF) for 2 h followed by intestinal fluid for 3 h, revealed the retention of the drug inside the microspheres from which only (15.27±0.56)% of the drug was released in 5 h. In vitro release rate studies were also carried out in simulated colonic fluid (SCF) in the presence of rat caecal contents, which showed improved drug release. The drug release from the formulation was found to be (41.6±3.5) % with 2% (w/v) caecal matter in 24 h as compared to control study where (25.2±3.5) % of drug was released. The drug release from the formulation with 2% and 4% rat caecal contents medium after 2 days of enzyme induction was found to be (56.3±4.1) % and (78.9±2.8) % in 24 h respectively. Similarly, (61.3±5.4) % and (90.2±2.9) % drug was released respectively with 2% and 4% rat caecal matter after 4 days of enzyme induction and (72.1±2.9) % and (90.2±3.2) % after 6 days of enzyme induction. In this way, 5-fluorouracil loaded guar gum microspheres have shown promising results in the management of colorectal cancer, warranting thorough in vivo study for scale up technology.

  9. Guar gum/borax hydrogel: Rheological, low field NMR and release characterizations

    OpenAIRE

    Grassi, M; T. Coviello; Matricardi, P; Alhaique, F.; Farra, R; G. Tesei; S. Fiorentino; F. Asaro; Milcovich, G.

    2013-01-01

    Guar gum (GG) and Guar gum/borax (GGb) hydrogels are studied by means of rheology, Low Field Nuclear Magnetic Resonance (LF NMR) and model drug release tests. These three approaches are used to estimate the mesh size (ζ) of the polymeric network. A comparison with similar Scleroglucan systems is carried out. In the case of GGb, the rheological and Low Field NMR estimations of ζ lead to comparable results, while the drug release approach seems to underestimate ζ. Such discrepanc...

  10. Nanoparticles with entrapped α-tocopherol: synthesis, characterization, and controlled release

    Science.gov (United States)

    Zigoneanu, Imola Gabriela; Astete, Carlos Ernesto; Mirela Sabliov, Cristina

    2008-03-01

    An emulsion evaporation method was used to synthesize spherical poly(DL-lactide-co-glycolide) (PLGA) nanoparticles with entrapped α-tocopherol. Two different surfactants were used: sodium dodecyl sulfate (SDS) and poly(vinyl alcohol) (PVA). For SDS nanoparticles, the size of the nanoparticles decreased significantly with the entrapment of α-tocopherol in the PLGA matrix, while the size of PVA nanoparticles remained unchanged. The polydispersity index after synthesis was under 0.100 for PVA nanoparticles and around 0.150 for SDS nanoparticles. The zeta potential was negative for all PVA nanoparticles. The entrapment efficiency of α-tocopherol in the polymeric matrix was approximately 89% and 95% for nanoparticles with 8% and 16% α-tocopherol theoretical loading, respectively. The residual PVA associated with the nanoparticles after purification was approximately 6% ( w/w relative to the nanoparticles). The release profile showed an initial burst followed by a slower release of the α-tocopherol entrapped inside the PLGA matrix. The release for nanoparticles with 8% α-tocopherol theoretical loading (86% released in the first hour) was faster than the release for the nanoparticles with 16% α-tocopherol theoretical loading (34% released in the first hour).

  11. Enteric-coated sustained-release nanoparticles by coaxial electrospray: preparation, characterization, and in vitro evaluation

    Science.gov (United States)

    Hao, Shilei; Wang, Bochu; Wang, Yazhou; Xu, Yingqian

    2014-02-01

    Enteric-coated formulations can delay the release of drugs until they have passed through the stomach. However, high concentration of drugs caused by rapidly released in the small intestine leads to the intestinal damage, and frequent administration would increase the probability of missing medication and reduce the patient compliance. To solve the above-mentioned problems, aspirin-loaded enteric-coated sustained-release nanoparticles with core-shell structure were prepared via one-step method using coaxial electrospray in this study. Eudragit L100-55 as pH-sensitive polymer and Eudragit RS as sustained-release polymer were used for the outer coating and inner core of the nanoparticles, respectively. The maximum loading capacity of nanoparticles was 23.66 % by changing the flow rate ratio of outer/inner solutions, and the entrapment efficiency was nearly 100 %. Nanoparticles with core-shell structure were observed via fluorescence microscope and transmission electron microscope. And pH-sensitive and sustained drug release profiles were observed in the media with different pH values (1.2 and 6.8). In addition, mild cytotoxicity in vitro was detected, and the nanoparticles could be taken up by Caco-2 cells within 1.0 h in cellular uptake study. These results indicate that prepared enteric-coated sustained-release nanoparticles would be a more safety and effective carrier for oral drug delivery.

  12. Sustained Release Floating Microspheres Of Acyclovir: Formulation, Optimization, Characterization And In Vitro Evaluation

    Directory of Open Access Journals (Sweden)

    Parmar Kunal Vinodbhai

    2011-03-01

    Full Text Available The aim of the present work was to prepare floating microspheres of acyclovir to prolong residence time in stomach and to sustain the release of acyclovir. Acyclovir loaded floating microspheres were prepared by double emulsion solvent evaporation method. The 32 full factorial design was applied to optimize the formulation. The resultant microspheres were evaluated for average particle size, percentage encapsulation efficiency, in vitro drug release and model fitting kinetics. Scanning electron microscopy, Fourier transform infrared (FTIR spectroscopy and differential scanning calorimetry were used to investigate the physical state of the drug in the microspheres. The particle size of microspheres was in the range of 275-340 µm. Percentage encapsulation efficiency was between 59%-77% w/w. Microspheres remained buoyant for more than about 12 h. The results of FT-IR spectroscopy and differential scanning calorimetry indicated the stable character of acyclovir in microspheres and also revealed absence of drugpolymer interaction. The in vitro drug release study showed that acyclovir release from the microspheres was slow and sustained for more than about 10 h. Drug release followed Korsemeyer-peppas model. The results of factorial batches revealed that the concentration of ethyl cellulose and stirring speed significantly affected drug encapsulation efficiency and particle size of the microspheres. Thus we can conclude that floating microspheres can successfully be developed to sustain the drug release.

  13. CHEMICAL MODIFICATION AND CHARACTERIZATION OF PECTIN AS A POTENTIAL DRUG RELEASE RETARDANT

    Directory of Open Access Journals (Sweden)

    Harika Puppala Satya Krishna

    2011-02-01

    Full Text Available The present study deals with the chemical modification of pectin by acetylation of their free hydroxyl groups to yield high ester pectin and to evaluate its solubility and swelling behaviour along with the effect on the release pattern of the drug. Modified pectins were prepared by acetylation process using various strengths of 20%, 40% and 60% v/v acetyl chloride in ethanol. The prepared modified pectins were subjected to various physico-chemical characteristics like solubility, gelling studies, acid value, saponification value and ester value. FTIR studies were carried out to confirm the chemical modification of pectin. Matrix tablets of tramadol were formulated using various strengths of modified pectins in different concentrations and its impact on drug release was studied. All the formulated batches were subjected to weight variation, hardness, friability, drug content and the values obtained were within the acceptable range. The in-vitro drug release characteristics from the formulated tablets were compared with commercial sustained release tablet of tramadol. The optimized tablet formulation F4 sustained the drug release over a period of 8hours as comparable to the marketed product. Thus the synthesized modified pectin proved to be an ideal drug release retarding polymer.

  14. Geohydrological characterization, water-chemistry, and ground-water flow simulation model of the Sonoma Valley area, Sonoma County, California

    Science.gov (United States)

    Farrar, Christopher D.; Metzger, Loren F.; Nishikawa, Tracy; Koczot, Kathryn M.; Reichard, Eric G.; Langenheim, V.E.

    2006-01-01

    changes by region. In recent years, pumping depressions have developed southeast of Sonoma and southwest of El Verano. Water-chemistry data for samples collected from 75 wells during 2002-04 indicate that the ground-water quality in the study area generally is acceptable for potable use. The water from some wells, however, contains one or more constituents in excess of the recommended standards for drinking water. The chemical composition of water from creeks, springs, and wells sampled for major ions plot within three groups on a trilinear diagram: mixed-bicarbonate, sodium-mixed anion, and sodium-bicarbonate. An area of saline ground water in the southern part of the Sonoma Valley appears to have shifted since the late 1940s and early 1950s, expanding in one area, but receding in another. Sparse temperature data from wells southwest of the known occurrence of thermal water suggest that thermal water may be present beneath a larger part of the valley than previously thought. Thermal water contains higher concentrations of dissolved minerals than nonthermal waters because mineral solubilities generally increase with temperature. Geohydrologic Characterization, Water-Chemistry, and Ground-Water Flow Simulation Model of the Sonoma Valley Area, Sonoma County, California Oxygen-18 (d18 O) and deuterium (dD) values for water from most wells plot along the global meteoric water line, indicating that recharge primarily is derived from the direct infiltration of precipitation or the infiltration of seepage from creeks. Samples from shallow- and intermediate-depth wells located near Sonoma Creek and (or) in the vicinity of Shellville plot to the right of the global meteoric water line, indicating that these waters are partly evaporated. The d18 O and dD composition of water from sampled wells indicates that water from wells deeper than 200 feet is isotopically lighter (more negative) than water from wells less than 200 feet deep, possibly indicating that older ground wate

  15. Characterization of nicotinic receptors involved in the release of noradrenaline from the hippocampus

    Energy Technology Data Exchange (ETDEWEB)

    Vizi, E.S. [Institute of Experimental Medicine, Hungarian Academy of Sciences, P.O. Box 67, H-1450 Budapest (Hungary); Lajtha, A. [Center of Neurochemistry, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY (United States); Balla, A. [Institute of Experimental Medicine, Hungarian Academy of Sciences, P.O. Box 67, H-1450 Budapest (Hungary); Sershen, H. [Center of Neurochemistry, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY (United States)

    1997-01-06

    The pharmacological features of putative nicotinic acetylcholine receptor sites involved in the release of [{sup 3}H]noradrenaline were assessed in rat hippocampus. The effect of nicotinic agonists to induce [{sup 3}H]noradrenaline release was examined in superfused slices. The nicotinic agonists (-)-epibatidine, (+)-anatoxin-a, dimethylphenylpiperazinium, (-)-nicotine and (-)-lobeline released [{sup 3}H]noradrenaline. The dose-response curves to nicotinic agonists were bell shaped, and indicated that their functional efficacies and potency vary across agonists. Maximal efficacy was seen with dimethylphenylpiperazinium and lobeline (E{sub max} values two to three times higher than other agonists). The rank order of potency for the agonists to release [{sup 3}H]noradrenaline was (-)-epibatidine (+)-anatoxin-a dimethylphenylpiperazinium cytisine nicotine (-)-lobeline. The nicotinic acetylcholine receptor antagonists [n-bungarotoxin (+)-tubocurarine hexamethonium>>{alpha}-bungarotoxin=dihydro-{beta}-erythroidine] and tetrodotoxin antagonized the effect of dimethylphenylpiperazinium to release [{sup 3}H]noradrenaline. The results, based on these pharmacological profiles, suggest the possible involvement of nicotinic acetylcholine receptor {alpha}3 and {beta}2 nicotinic acetylcholine receptor subunits in the control of [{sup 3}H]noradrenaline release from hippocampal slices. The absence of effect of {alpha}-bungarotoxin and {alpha}-conotoxin-IMI excludes the possible involvement of nicotinic acetylcholine receptors containing the {alpha}7 subunit. The release of [{sup 3}H]noradrenaline by dimethylphenylpiperazinium was Ca{sup 2+} dependent. Nifedipine failed to prevent the dimethylphenylpiperazinium-induced release of [{sup 3}H]noradrenaline, but Cd{sup 2+}, {omega}-conotoxin and Ca{sup 2+}-free conditions significantly reduced the dimethylphenylpiperazinium-induced release, suggesting that N-type voltage-sensitive Ca{sup 2+} channels are involved in the nicotinic

  16. Underground object characterization based on neural networks for ground penetrating radar data

    Science.gov (United States)

    Zhang, Yu; Huston, Dryver; Xia, Tian

    2016-04-01

    In this paper, an object characterization method based on neural networks is developed for GPR subsurface imaging. Currently, most existing studies demonstrate detecting and imaging objects of cylindrical shapes. While in this paper, no restriction is imposed on the object shape. Three neural network algorithms are exploited to characterize different types of object signatures, including object shape, object material, object size, object depth and subsurface medium's dielectric constant. Feature extraction is performed to characterize the instantaneous amplitude and time delay of the reflection signal from the object. The characterization method is evaluated utilizing the data synthesized with the finite-difference timedomain (FDTD) simulator.

  17. Heliocentric Distance of Coronal Mass Ejections at the Time of Energetic Particle Release: Revisiting the Ground Level Enhancement Events of Solar Cycle 23

    Science.gov (United States)

    Gopalswamy, Natchimuthuk

    2011-01-01

    Using the kinematics of coronal mass ejections (CMEs), onset time of soft X-ray flares, and the finite size of the pre-eruption CME structure, we derive the heliocentric distane at which the energetic particles during the ground level enhancement (GLE) events of Solar Cycle 23. We find that the GLE particles are released when the CMEs reach an average heliocentric distance of approx.3.25 solar radii (Rs). From this we infer that the shocks accelerating the particles are located at similar heights. Type II radio burst observations indicate that the CMEs are at much lower distances (average approx.1.4 Rs) when the CME-driven shock first forms. The shock seems to travel approx.1.8 Rs over a period of approox.30 min on the average before releasing the GLE particles. In deriving these results, we made three assumptions that have observational support: (i) the CME lift off occurs from an initial distance of about 1.25 Rs; (ii) the flare onset and CME onset are one and the same because these are two different manifestations of the same eruption; and (iii) the CME has positive acceleration from the onset to the first appearance in the coronagraphic field of view (2.5 to 6 Rs). Observations of coronal cavities in eclipse pictures and in coronagraphic images justify the assumption (i). The close relationship between the flare reconnection magnetic flux and the azimuthal flux of interplanetary magnetic clouds justify assumption (ii) consistent with the standard model (CSHKP) of solar eruption. Coronagraphic observations made close to the solar surface indicate a large positive acceleration of CMEs to a heliocentric distance of approx.3 Rs before they start slowing down due to the drag force. The inferred acceleration (approx.1.5 km/s/s) is consistent with reported values in the literature.

  18. Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

    KAUST Repository

    Nath, Sankar Kumar

    2013-12-01

    We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

  19. Ciprofloxacin Controlled-Solid Lipid Nanoparticles: Characterization, In Vitro Release, and Antibacterial Activity Assessment

    Science.gov (United States)

    2017-01-01

    The objective of this research was to formulate ciprofloxacin (CIP) in solid lipid nanoparticles (SLNs) in an attempt to develop a controlled drug delivery system. An ultrasonic melt-emulsification method was used for preparing CIP-loaded SLNs. Key findings included that SLNs were successfully produced with average particle sizes ranging from 165 to 320 nm and polydispersity index in the range of 0.18–0.33. High entrapment efficiency values were reported in all formulations. The atomic force scanning microscopic images showed spherical shape with the size range closer to those found by the particle size analyzer. CIP release exhibited controlled-release behavior with various lipids. Ciprofloxacin solid lipid nanoparticles formula containing stearic acid (CIPSTE) displayed the strongest burst effect and the most rapid release rate. The release data revealed a better fit to the Higuchi diffusion model. After storing the CIPSTE formula at room temperature for 120 days, no significant difference in particle size and zeta potential was found. CIP-loaded SLNs exhibited superior antibacterial activity. Incorporation of CIP into SLNs leads to controlled release and a superior antibacterial effect of CIP. PMID:28194408

  20. Ciprofloxacin Controlled-Solid Lipid Nanoparticles: Characterization, In Vitro Release, and Antibacterial Activity Assessment

    Directory of Open Access Journals (Sweden)

    Gamal A. Shazly

    2017-01-01

    Full Text Available The objective of this research was to formulate ciprofloxacin (CIP in solid lipid nanoparticles (SLNs in an attempt to develop a controlled drug delivery system. An ultrasonic melt-emulsification method was used for preparing CIP-loaded SLNs. Key findings included that SLNs were successfully produced with average particle sizes ranging from 165 to 320 nm and polydispersity index in the range of 0.18–0.33. High entrapment efficiency values were reported in all formulations. The atomic force scanning microscopic images showed spherical shape with the size range closer to those found by the particle size analyzer. CIP release exhibited controlled-release behavior with various lipids. Ciprofloxacin solid lipid nanoparticles formula containing stearic acid (CIPSTE displayed the strongest burst effect and the most rapid release rate. The release data revealed a better fit to the Higuchi diffusion model. After storing the CIPSTE formula at room temperature for 120 days, no significant difference in particle size and zeta potential was found. CIP-loaded SLNs exhibited superior antibacterial activity. Incorporation of CIP into SLNs leads to controlled release and a superior antibacterial effect of CIP.

  1. Synthesis and characterizations of a fluoride-releasing dental restorative material.

    Science.gov (United States)

    Khan, Abdul Samad; Aamer, Sidra; Chaudhry, Aqif Anwar; Wong, Ferranti S L; Ur Rehman, Ihtesham

    2013-08-01

    The aim was to develop an obturating material which has the tendency to release fluoride and minimize interfaces with tooth. Nano-fluorapatite (nFA) powder was synthesized by sol-gel. The composite based on polyurethane (PU) was obtained by chemically binding the nFA (10, 15, 20%wt/wt) to the diisocyanate component by utilizing in-situ polymerization. The procedure involved stepwise addition of monomeric units of PU, and optimizing the reagent concentrations to synthesize composite. The structural, phase and morphological analysis of nFA was evaluated. The structural, fluoride release and in-vitro adhesion analysis with tooth structure of PU/nFA was conducted. For fluoride release analysis the samples were stored in artificial saliva and deionized water for periodical time intervals. Bond strength of composites was analyzed by push-out test. Chemical linkage was achieved between PU and nFA without intermediate coupling agent. The insignificant difference of fluoride release pattern was observed in artificial saliva and (p≥0.05) deionized water. The PU/nFA composite provided sustained release of fluoride over a long period of time. The composite showed more adhesion toward tooth structure with the increase in concentration of nFA. Bond strength of composite was in accordance with root canal filling material, hence, the material with anti-cariogenic properties can be used as an obturating material.

  2. Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment

    OpenAIRE

    De Brito, J.; Rizzo, L. V.; Morgan, W. T.; Coe, H.; Johnson, B; Haywood, J.; LONGO, K.; Freitas, S.; Andreae, M. O.; Artaxo, P.

    2014-01-01

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field ...

  3. Isolation and partial characterization of a lectin from ground elder (Aegopodium podagraria) rhizomes.

    Science.gov (United States)

    Peumans, W J; Nsimba-Lubaki, M; Peeters, B; Broekaert, W F

    1985-05-01

    A lectin has been isolated from rhizomes of ground elder (Aegopodium podagraria) using a combination of affinity chromatography on erythrocyte membrane proteins immobilized on cross-linked agarose and hydroxyapatite, and ion-exchange chromatography. The molecular structure of the lectin was determined by gelfiltration, sucrose density-gradient centrifugation and gel electrophoresis under denaturing conditions. It has an unusually high Mr (about 480000) and is most probably an octamer composed of two distinct types of subunits with slightly different Mr (about 60000). Hapten inhibition assays indicated that the Aegopodium lectin is preferentially inhibited by N-acetylgalactosamine. Nevertheless, it does not agglutinate preferentially blood-group-A erythrocytes. The ground-elder lectin is a typical non-seed lectin, which occurs virtually exclusively in the underground rhizomes. In this organ it is an abundant protein as it represents up to 5% of the total protein content. The lectin content of the rhizome tissue varies strongly according to its particular location along the organ. In addition, the lectin content changes dramatically as a function of the seasons. The ground-elder lectin differs from all other plant lectins by its unusually high molecular weight. In addition, it is the first lectin to be isolated from a species of the family Apiaceae.

  4. Performance characterization and ground testing of an airborne CO2 differential absorption lidar system (phase II)

    Science.gov (United States)

    Senft, Daniel C.; Fox, Marsha J.; Hamilton, Carla M.; Richter, Dale A.; Higdon, N. S.; Kelly, Brian T.

    1999-05-01

    The Air Force Research Laboratory (AFRL) Active Remote Sensing Branch has developed the Laser Airborne Remote Sensing (LARS) system for chemical detection using the differential absorption lidar (DIAL) technique. The system is based on a high-power CO2 laser which can use either the standard 12C16O2 or the 13C16O2 carbon dioxide isotopes as the lasing medium, and has output energies of up to 5 J on the stronger laser transitions. The lidar system is mounted on a flight-qualified optical breadboard designed for installation into the AFRL Argus C- 135E optical testbed aircraft. The Phase I ground tests were conducted at Kirtland AFB in 1997, prior to the LARS flight tests performed in September 1997 at Kirtland AFB and the Idaho National Engineering and Environmental Laboratory (INEEL). The Phase II ground tests were conducted in 1998 to determine the optimum performance of the LARS system, after the incorporation of modification and improvements suggested by the flight test results. This paper will present some of the chemical detection and radiometric results obtained during the Phase II ground tests.

  5. Morpho-physiological characterization of grapevine attacked by ground-pearl

    Directory of Open Access Journals (Sweden)

    Marcelo Zart

    2014-06-01

    Full Text Available The ground pearl Eurhizoccoccus brasiliensis (Hemiptera: Margarodidae, is an important pest of Brazilian viticulture, related to symptoms of decline and death of plants. Despite this evidence, there is no technical information on insect-plant interactions and how the symptoms are established. Therefore, this study aimed to expose the physiological mechanisms related to the symptoms of the ground pearl attack. Seedlings of ‘Cabernet Sauvignon’ and adult plants of a commercial vineyard of ‘Isabel’, were evaluated in vegetative development of commercial area, nutrition and metabolism of leaves by the contrast of healthy and infested plants by the insect. In attacked plants it was possible to verify a significant reduction of vegetative growth. However, foliar symptoms were not expressed in two years old seedlings. In adult plants attacked, leaves, tissues of branches, roots and fruits were evaluated. The largest effects were observed in necrotic leaves, which showed a reduction of potassium (-26%, boron (-21%, total chlorophyll (-43% and photosynthetic rate (-45%, in comparison to healthy plants. However, these same necrotic leaves showed a significant accumulation of starch (+316%. Therefore, these results suggest that ground pearl promotes the symptoms on the vine in a systemic way by blocking the transport of assimilates from leaves to other plant tissues.

  6. Surface Signature Characterization at SPE through Ground-Proximal Methods: Methodology Change and Technical Justification

    Energy Technology Data Exchange (ETDEWEB)

    Schultz-Fellenz, Emily S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-09

    A portion of LANL’s FY15 SPE objectives includes initial ground-based or ground-proximal investigations at the SPE Phase 2 site. The area of interest is the U2ez location in Yucca Flat. This collection serves as a baseline for discrimination of surface features and acquisition of topographic signatures prior to any development or pre-shot activities associated with SPE Phase 2. Our team originally intended to perform our field investigations using previously vetted ground-based (GB) LIDAR methodologies. However, the extended proposed time frame of the GB LIDAR data collection, and associated data processing time and delivery date, were unacceptable. After technical consultation and careful literature research, LANL identified an alternative methodology to achieve our technical objectives and fully support critical model parameterization. Very-low-altitude unmanned aerial systems (UAS) photogrammetry appeared to satisfy our objectives in lieu of GB LIDAR. The SPE Phase 2 baseline collection was used as a test of this UAS photogrammetric methodology.

  7. Numerical characterization of heat transfer in closed-loop vertical ground heat exchanger

    Institute of Scientific and Technical Information of China (English)

    Chulho; LEE; Hujeong; GIL; Hangseok; CHOI; Shin-Hyung; KANG

    2010-01-01

    A series of numerical analyses has been performed on the characteristics of heat transfer in a closed-loop vertical ground heat exchanger(U-loop).A 2-D finite element analysis was conducted to evaluate the temperature distribution over the cross section of the U-loop system involving high-density polyethylene(HDPE) pipe/grout/soil to compare the sectional efficiency between the conventional U-loop and a new latticed HDPE pipe system,which is equipped with a thermally insulating lattice in order to reduce thermal interference between the inlet and outlet pipes.In addition,a 3-D finite volume analysis(FLUENT) was adopted to simulate the operation of the closed-loop vertical ground heat exchanger with the consideration of the effect of a distance between the inlet and outlet pipes,grout’s thermal properties,the effectiveness of the latticed HDPE pipe system,and the rate of circulation pump.It was observed that the thermal interference between the two strands of U-loop is of importance in enhancing efficiency of the ground heat exchanger.Consequently,it is recommended to modify the configuration of the conventional U-loop system by equipping the thermally insulating lattice between the two pipe strands.

  8. Development of CNC prototype for the characterization of the nanoparticle release during physical manipulation of nanocomposites.

    Science.gov (United States)

    Gendre, Laura; Marchante, Veronica; Abhyankar, Hrushikesh A; Blackburn, Kim; Temple, Clive; Brighton, James L

    2016-01-01

    This work focuses on the release of nanoparticles from commercially used nanocomposites during machining operations. A reliable and repeatable method was developed to assess the intentionally exposure to nanoparticles, in particular during drilling. This article presents the description and validation of results obtained from a new prototype used for the measurement and monitoring of nanoparticles in a controlled environment. This methodology was compared with the methodologies applied in other studies. Also, some preliminary experiments on drilling nanocomposites are included. Size, shape and chemical composition of the released nanoparticles were investigated in order to understand their hazard potential. No significant differences were found in the amount of nanoparticles released between samples with and without nanoadditives. Also, no chemical alteration was observed between the dust generated and the bulk material. Finally, further developments of the prototype are proposed.

  9. Design, Development and Characterization of Extended Release Multiunit Particulate System of Anti-Inflammatory Drug

    Directory of Open Access Journals (Sweden)

    Dhiren Daslaniya

    2009-07-01

    Full Text Available Multi unit particulate system has long been employed to improve the bioavailability of drugs. Mesalamine pellets were prepared by Coating drug solution on sugar sphere followed by various functional coating. The influence of rate controlling membrane made up of Eudragit RSPO and Eudragit RLPO in combination with delay release polymer coating with Eudragit L100 in different proportions on drug release kinetics was studied. Pellets were for the various parameter like Physical characteristics, assay and in-vitro dissolution profile. The study confirmed that mesalamine can be delivered by multi unit particulate system into lower part of intestine. Optimized formulations were evaluated for In-vitro release profile. The optimized formula was stable at accelerated storage condition 40°C / 75 % RH. Prepared Pellets can be used in the treatment of the ulcerative colitis.

  10. Guar gum/borax hydrogel: Rheological, low field NMR and release characterizations

    Directory of Open Access Journals (Sweden)

    M. Grassi

    2013-09-01

    Full Text Available Guar gum (GG and Guar gum/borax (GGb hydrogels are studied by means of rheology, Low Field Nuclear Magnetic Resonance (LF NMR and model drug release tests. These three approaches are used to estimate the mesh size (ζ of the polymeric network. A comparison with similar Scleroglucan systems is carried out. In the case of GGb, the rheological and Low Field NMR estimations of ζ lead to comparable results, while the drug release approach seems to underestimate ζ. Such discrepancy is attributed to the viscous effect of some polymeric chains that, although bound to the network to one end, can freely fluctuate among meshes. The viscous drag exerted by these chains slows down drug diffusion through the polymeric network. A proof for this hypothesis is given by the case of Scleroglucan gel, where the viscous contribution is not so significant and a good agreement between the rheological and release test approaches was found.

  11. Chitosan-DNA microparticles as mucosal delivery system:synthesis, characterization and release in vitro

    Institute of Scientific and Technical Information of China (English)

    LI Yu-hong; FAN Min-wen; BIAN Zhuan; CHEN Zhi; ZHANG Qi; YANG Hai-rui

    2005-01-01

    Background Mucosal immunity is important to defense against dental caries. To enhance mucosal immunity, a DNA vaccine mucosal delivery system was prepared by encapsulating anticaries DNA vaccine (plasmid pGJA-P/VAX) in chitosan under optimal conditions and the characteristics of the microparticles was investigated. Furthermore, the release properties and protective action of microparticles for plasmid were studied in vitro.Methods Plasmid loaded chitosan microparticles were prepared by complex coacervation. Three factors, concentration of DNA, sodium sulfate, and the chitosan/DNA ratios in complexes [better expressed as N/P ratio: the number of poly nitrogen (N) per DNA phosphate (P)] influencing preparation were optimized by orthogonal test. The characteristics of microparticles were evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). DNA release rate of microparticles in similar gastro fluid (SGF) or similar intestinal fluid (SIF) at 37℃ was determined by ultraviolet spectrophotometry.Results High encapsulation efficiency (96.8%) was obtained with chitosan microparticles made under optimal conditions of 50 mmol/L Na2SO4, 200 μg/ml DNA and N/P ratio of 4. The size of particles was about 4 to 6 μm. The encapsulation process did not destroy the integrity of DNA. When incubated with SIL, after a release of about 10% in the first 60 minutes, no further DNA was released during the following 180 minutes. When incubated with SGL, the microparticles released a small burst (about 11%) in the first 60 minutes, and then slowly released at a constant, but different rate.Conclusions These chitosan microparticles showed suitable characteristics in vitro for mucosal vaccination and are therefore a promising carrier system for DNA vaccine mucosal delivery.

  12. Characterization of hydrophobic flavor release profile in oil-in-water emulsions.

    Science.gov (United States)

    Giroux, H J; Perreault, V; Britten, M

    2007-03-01

    An instrumental approach to better understand the release and persistence of flavor in oil-in-water emulsions has been developed. Emulsions were prepared with various whey protein (0.1% to 3.16%), sunflower oil (1% to 8%), and ethyl hexanoate (0% to 0.04%) concentrations. Flavor release profile in real time was measured at 37 degrees C using a specially designed glass cell connected directly to a gas chromatograph equipped with a flame ionization detector. The intensity of flavor released from the emulsion stirred at a shear rate of 100 s(-1) was monitored as a function of time and data were fitted to a 1st-order kinetic equation. Maximum intensity and decay rate constant were both determined from the model and the persistence index (inversely associated to decay rate constant) was calculated. For constant aroma concentration in the emulsion, maximum intensity significantly decreased as whey protein and oil concentrations increased. For increasing aroma concentration, maximum intensity was directly proportional to the ethyl hexanoate concentration when the oil content was kept constant but leveled off when oil content was increased. Persistence of flavor significantly increased with increasing protein and oil concentrations while aroma concentrations had no effect when oil content was constant. The results showed that oil concentration had a greater influence on flavor release characteristics than protein concentration. Aroma concentration in the oil phase, rather than in the emulsion, determines the kinetics of hydrophobic flavor release. The method provides a useful tool for the rapid and reproducible measurement of flavor release profile.

  13. Preparation and Characterization of Ionotropic Cross-Linked Chitosan Microparticles for Controlled Release of Aceclofenac

    Directory of Open Access Journals (Sweden)

    N. G. Raghavendra Rao

    2010-04-01

    Full Text Available Aceclofenac, (2-[2-[2-(2, 6-dichlorophenyl aminophenyl] acety] oxyacetic acid a non-steroidal anti-inflammatory drug (NSAID, has been indicated for various conditions like post-traumatic pain, rheumatoid arthritis, ankylosing spondylitis. Multiple-unit systems have been reported to avoid the variations in gastric emptying and different transit rates through gastro-intestinal and spread over a large area preventing exposure of the absorbing site to high drug concentration on chronic dosing. The purpose of this study was therefore to develop aceclofenac loaded chitosan microparticles by ionotropic gelation method. Drug loading efficiency (DLE of microparticles was found between 62.20 to 92.93 % and depended on the formulation variables. Increase in the Tripolyphosphate (TPP concentration, pH of the TPP solution and cross-linking time decreased the drug release. The particle size decreased with increase in cross-linking time and found between the ranges of 1194.1 to 1568.9 µm. Drug release showed slight burst effect in phosphate buffer pH 7.4 in first hour followed by prolonged release for 8 hrs. FTIR and DSC revealed that there was no interaction between drug and polymer. The release data was fitted into first order, zero order and Higuchi model to find release kinetics. The values of regression coefficient r2 were found to be greater (£ 0.9541 for first order than for zero order (£ 0.8740 and the r2 value for Higuchi was £ 0.9805 suggesting diffusion controlled process. The result concluded that TPP-chitosan microparticles developed by ionotropic gelation method might become potential delivery system to prolonging the release of aceclofenac.

  14. Design, synthesis, characterization and drug release kinetics of PAMAM dendrimer based drug formulations

    Science.gov (United States)

    Kurtoglu, Yunus Emre

    The drug release characteristics of G4-polyamidoamine (PAMAM) dendrimer-ibuprofen conjugates with ester, amide, and peptide linkers were investigated, in addition to a linear PEG-ibuprofen conjugate to understand the effect of architecture and linker on drug release. Ibuprofen was directly conjugated to NH2 -terminated dendrimer by an amide bond and OH-terminated dendrimer by an ester bond. A tetra-peptide linked dendrimer conjugate and a linear mPEG-ibuprofen conjugate were also studied for comparison to direct linked dendrimer conjugates. It is demonstrated that the 3-D nanoscale architecture of PAMAM dendrimer-drug conjugates, along with linking chemistry govern the drug release mechanisms as well as kinetics. Understanding these structural effects on their drug release characteristics is crucial for design of dendrimer conjugates with high efficacy such as poly(amidoamine) dendrimer-N-Acetylcysteine conjugates with disulfide linkages. N-Acetylcysteine (NAC) is an anti-inflammatory agent with significant potential for clinical use in the treatment of neuroinflammation, stroke and cerebral palsy. A poly(amidoamine) dendrimer-NAC conjugate that contains a disulfide linkage was synthesized and evaluated for its release kinetics in the presence of glutathione (GSH), Cysteine (Cys), and bovine serum albumin (BSA) at both physiological and lysosomal pH. FITC-labeled conjugates showed that they enter cells rapidly and localize in the cytoplasm of lipopolysaccharide (LPS)-activated microglial cells. The efficacy of the dendrimer-NAC conjugate was measured in activated microglial cells using reactive oxygen species (ROS) assays. The conjugates showed an order of magnitude increase in anti-oxidant activity compared to free drug. When combined with intrinsic and ligand-based targeting with dendrimers, these types of GSH sensitive nanodevices can lead to improved drug release profiles and in vivo efficacy.

  15. Quantification and characterization of cell wall polysaccharides released by non-Saccharomyces yeast strains during alcoholic fermentation.

    Science.gov (United States)

    Giovani, Giovanna; Rosi, Iolanda; Bertuccioli, Mario

    2012-11-15

    In order to improve knowledge about the oenological characteristics of non-Saccharomyces yeast strains, and to reconsider their contribution to wine quality, we studied the release of polysaccharides by 13 non-Saccharomyces strains of different species (three wine yeasts, six grape yeasts, and three spoilage yeasts) during alcoholic fermentation in synthetic must. Three Saccharomyces cerevisiae strains were included for comparison. All of the non-Saccharomyces strains released polysaccharides into fermentation medium; the amount released depended on the yeast species, the number of cells formed and their physiological conditions. Normalizing the quantity of macromolecules released to the cell biomass revealed that most non-Saccharomyces strains produced a greater quantity of polysaccharides compared to S. cerevisiae strains after 7 and 14days of fermentation. This capacity was particularly expressed in the studied wine spoilage yeasts (Saccharomycodes ludwigii, Zygosaccharomyces bailii, and Brettanomyces bruxellensis). Chemical characterization of exocellular polysaccharides produced by non-Saccharomyces yeasts revealed them to essentially be mannoproteins with high mannose contents, ranging from 93% for S'codes. ludwigii to 73-74% for Pichia anomala and Starmerella bombicola. Protein contents varied from 9% for P. anomala to 29% for Z. bailii. These compositions were very similar to those of the S. cerevisiae strains, and to the chemical composition of the cell wall mannoproteins of different yeast species. The presence of galactose, in addition to mannose and glucose, in the exocellular polysaccharides released by Schizosaccharomyces pombe, confirmed the parietal nature of the polysaccharides released by non-Saccharomyces yeasts; only this species has a galactomannan located in the outer layer of the cell wall.

  16. Characterization of drug-release kinetics in trabecular bone from titania nanotube implants

    Directory of Open Access Journals (Sweden)

    Aw MS

    2012-09-01

    Full Text Available Moom Sinn Aw,1 Kamarul A Khalid,2,3 Karan Gulati,1 Gerald J Atkins,2 Peter Pivonka,4 David M Findlay,2 Dusan Losic11School of Chemical Engineering, 2Discipline of Orthopaedics and Trauma, The University of Adelaide, Adelaide, SA, Australia; 3Department of Orthopaedics, Traumatology and Rehabilitation, Faculty of Medicine, International Islamic University Malaysia, Kuantan, Pahang, Malaysia; 4Engineering Computational Biology Group, School of Computer Science and Software Engineering, The University of Western Australia, Perth, WA, AustraliaPurpose: The aim of this study was to investigate the application of the three-dimensional bone bioreactor for studying drug-release kinetics and distribution of drugs in the ex vivo cancellous bone environment, and to demonstrate the application of nanoengineered titanium (Ti wires generated with titania nanotube (TNT arrays as drug-releasing implants for local drug deliveryMethods: Nanoengineered Ti wires covered with a layer of TNT arrays implanted in bone were used as a drug-releasing implant. Viable bovine trabecular bone was used as the ex vivo bone substrate embedded with the implants and placed in the bone reactor. A hydrophilic fluorescent dye (rhodamine B was used as the model drug, loaded inside the TNT–Ti implants, to monitor drug release and transport in trabecular bone. The distribution of released model drug in the bone was monitored throughout the bone structure, and concentration profiles at different vertical (0–5 mm and horizontal (0–10 mm distances from the implant surface were obtained at a range of release times from 1 hour to 5 days.Results: Scanning electron microscopy confirmed that well-ordered, vertically aligned nanotube arrays were formed on the surface of prepared TNT–Ti wires. Thermogravimetric analysis proved loading of the model drug and fluorescence spectroscopy was used to show drug-release characteristics in-vitro. The drug release from implants inserted into bone ex

  17. Characterizing Ground-Water Flow Paths in High-Altitude Fractured Rock Settings Impacted by Mining Activities

    Science.gov (United States)

    Wireman, M.; Williams, D.

    2003-12-01

    The Rocky Mountains of the western USA have tens of thousands of abandoned, inactive and active precious-metal(gold,silver,copper)mine sites. Most of these sites occur in fractured rock hydrogeologic settings. Mining activities often resulted in mobilization and transport of associated heavy metals (zinc,cadmium,lead) which pose a significant threat to aquatic communities in mountain streams.Transport of heavy metals from mine related sources (waste rock piles,tailings impoudments,underground workings, mine pits)can occur along numerous hydrological pathways including complex fracture controlled ground-water pathways. Since 1991, the United States Environmental Protection Agency, the Colorado Division of Minerals and Geology and the University of Colorado (INSTAAR)have been conducting applied hydrologic research at the Mary Murphy underground mine. The mine is in the Chalk Creek mining district which is located on the southwestern flanks of the Mount Princeton Batholith, a Tertiary age intrusive comprised primarily of quartz monzonite.The Mount Princeton batholith comprises a large portion of the southern part of the Collegiate Range west of Buena Vista in Chaffee County, CO. Chalk Creek and its 14 tributaries drain about 24,900 hectares of the eastern slopes of the Range including the mining district. Within the mining district, ground-water flow is controlled by the distribution, orientation and permeability of discontinuities within the bedrock. Important discontinuities include faults, joints and weathered zones. Local and intermediate flow systems are perturbed by extensive underground excavations associated with mining (adits, shafts, stopes, drifts,, etc.). During the past 12 years numerous hydrological investigations have been completed. The investigations have been focused on developing tools for characterizing ground-water flow and contaminant transport in the vicinity of hard-rock mines in fractured-rock settings. In addition, the results from these

  18. Preparation and Characterization of Zein and Zein-Chitosan Microspheres with Great Prospective of Application in Controlled Drug Release

    Directory of Open Access Journals (Sweden)

    Vinícius Müller

    2011-01-01

    Full Text Available Biomaterials applied as carriers for controlled drug delivery offer many advantages over the conventional systems. Among them, the increase of treatment effectiveness and also a significant reduction of toxicity, due to their biodegradability property, are some special features. In this work, microspheres based on the protein Zein (ZN and ZN associated to the natural polymer Chitosan (CHI were prepared and characterized. The microspheres of ZN and ZN/CHI were characterized by FT-IR spectroscopy and thermal analysis, and the morphology was analyzed by SEM images. The results confirmed the incorporation of CHI within the ZN-based microspheres. The morphological analysis showed that the CHI added increased the microspheres porosity when compared to the ZN microspheres. The chemical and physical characterization and the morphological analysis allow inferring that ZN/CHI microspheres are good candidates to act as a carrier for controlled drug release.

  19. Characterization and analysis of Devonian shales as related to release of gaseous hydrocarbons. Well K-4 Johnson County, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Kalyoncu, R.S.; Snyder, M.J.

    1979-08-15

    Various characterization tasks were performed on 54 cored shale samples from Johnson County, Kentucky. Core samples were obtained from depths of 967 to 1510 feet. A total of 126 samples were canned for several DOE contractors, including Battelle Columbus. Free gas analyses indicate the presence of significant quantities of higher chain hydrocarbon gases in the K-4 shales. Hydrocarbon gas release rates and kinetic studies indicate that diffusion coefficients are inversely proportional to the square root of the molecular weight of diffusing species. Although wide scatter is observed in the chemical and physical characterization data, good correlations exist between the hydrocarbon gas contents and various laboratory characterization values (physical and chemical). A number of one-to-one relationships are pointed out and discussed. Lithologically, inorganic portions of K-4 shales are composed predominantly of quartz and illite with small quantities of pyrite and various carbonate minerals.

  20. Depleted uranium risk assessment for Jefferson Proving Ground using data from environmental monitoring and site characterization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ebinger, M.H.; Hansen, W.R.

    1996-10-01

    This report documents the third risk assessment completed for the depleted uranium (DU) munitions testing range at Jefferson Proving Ground (JPG), Indiana, for the U.S. Army Test and Evaluation command. Jefferson Proving Ground was closed in 1995 under the Base Realignment and Closure Act and the testing mission was moved to Yuma Proving Ground. As part of the closure of JPG, assessments of potential adverse health effects to humans and the ecosystem were conducted. This report integrates recent information obtained from site characterization surveys at JPG with environmental monitoring data collected from 1983 through 1994 during DU testing. Three exposure scenarios were evaluated for potential adverse effects to human health: an occasional use scenario and two farming scenarios. Human exposure was minimal from occasional use, but significant risk were predicted from the farming scenarios when contaminated groundwater was used by site occupants. The human health risk assessments do not consider the significant risk posed by accidents with unexploded ordnance. Exposures of white-tailed deer to DU were also estimated in this study, and exposure rates result in no significant increase in either toxicological or radiological risks. The results of this study indicate that remediation of the DU impact area would not substantially reduce already low risks to humans and the ecosystem, and that managed access to JPG is a reasonable model for future land use options.

  1. Characterizing demographics, injury severity, and intubation status for patients transported by air or ground ambulance to a rural burn center.

    Science.gov (United States)

    Ahmed, Azeemuddin; Van Heukelom, Paul; Harland, Karisa; Denning, Gerene; Liao, Junlin; Born, Janelle; Latenser, Barbara

    2014-01-01

    Our study was designed to characterize intubation status among patients transported by air or ground ambulance to a rural burn center. A retrospective chart review of patients arriving at our burn center from January 1, 2005 to December 31, 2009 was completed. Descriptive and multivariate analyses were performed. During the study period, 259 air and 590 ground ambulance patients met inclusion criteria. Air ambulance patients were older and had higher total body surface area burned, lower Glasgow Coma scores, longer lengths of stay, and more frequent inhalation injuries. Approximately 10% of patients arriving by air were intubated after burn center admission, and 49% of intubated patients were extubated within 24 hours of admission. These values were 2% and 40%, respectively, for patients transported by ground. Increasing age and air ambulance transport increased the overall likelihood of change in intubation status. The likelihood of intubation by burn center providers increased with age, with suspicion of inhalation injury, and for patients transported by air. The likelihood of extubation within 24 hours of burn center admission increased with age, decreased with suspected inhalation injury, and was independent of transport mode. Among our patient population, more severely injured patients were being transported by air ambulance. However, age, suspicion of inhalation injury, and mode of transport showed a complex pattern of associations with changes in intubation status, and illustrate the need to develop better prehospital guidelines for intubation in burn patients.

  2. Magnetic glass ceramics for sustained 5-fluorouracil delivery: characterization and evaluation of drug release kinetics.

    Science.gov (United States)

    Abdel-Hameed, S A M; El-Kady, A M; Marzouk, M A

    2014-11-01

    In the present study, magnetic glass ceramics in the system Fe2O3 ∙ TiO2 ∙ P2O5 ∙ SiO2 ∙ MO (M=Mg, Ca, Mn, Cu, Zn or Ce) are prepared. The effect of adding different cations on the thermal behavior, developed phases, microstructure and magnetic properties is studied using differental thermal analysis (DTA), X-ray diffraction analysis (XRD), transmission electron microscope (TEM), FT-infrared transmission (FT-IR) and vibrating sample magnetometer (VSM) respectively. The magnetic glass ceramics are tested as delivery systems for 5-fluorouracil. Modeling and analysis of release kinetics are addressed. The application of Higuchi square root of time model and the first order release model indicated that, 5-FU is released by diffusion controlled mechanisms, and that its released rate depends greatly on the concentration of loaded drug during the loading stage. The obtained results suggested that, the prepared magnetic glass ceramics can be used for cancer treatment by hyperthermia and/or by localized delivery of therapeutic doses of 5-fluorouracil.

  3. β-Cyclodextrin inclusion complex: preparation, characterization, and its aspirin release in vitro

    Science.gov (United States)

    Zhou, Hui-Yun; Jiang, Ling-Juan; Zhang, Yan-Ping; Li, Jun-Bo

    2012-09-01

    In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin (Asp-β-CD) inclusion complex using design of experiment (DOE) methodology. A 3-level, 3-factor Box-Behnken design with a total of 17 experimental runs was used. The Asp-β-CD inclusion complex was prepared by saturated solution method. The influence on the embedding rate was investigated, including molar ratio of β-CD to Asp, clathration temperature and clathration time, and the optimum values of such three test variables were found to be 0.82, 49°C and 2.0 h, respectively. The embedding rate could be up to 61.19%. The formation of the bonding between -COOH group of Asp and O-H group of β-CD might play an important role in the process of clathration according to FT-IR spectra. Release kinetics of Asp from inclusion complex was studied for the evaluation of drug release mechanism and diffusion coefficients. The results showed that the drug release from matrix occurred through Fickian diffusion mechanism. The cumulative release of Asp reached only 40% over 24 h, so the inclusion complex could potentially be applied as a long-acting delivery system.

  4. Method for isolation and molecular characterization of extracellular microvesicles released from brain endothelial cells

    OpenAIRE

    Haqqani Arsalan S; Delaney Christie E; Tremblay Tammy-Lynn; Sodja Caroline; Sandhu Jagdeep K; Stanimirovic Danica B

    2013-01-01

    Abstract Background In addition to possessing intracellular vesicles, eukaryotic cells also produce extracellular microvesicles, ranging from 50 to 1000 nm in diameter that are released or shed into the microenvironment under physiological and pathological conditions. These membranous extracellular organelles include both exosomes (originating from internal vesicles of endosomes) and ectosomes (originating from direct budding/shedding of plasma membranes). Extracellular microvesicles contain ...

  5. Preparation and Characterization of Oxidized Starch Polymer Microgels for Encapsulation and Controlled Release of Functional Ingredients

    NARCIS (Netherlands)

    Li, Yuan; de Vries, Renko; Slaghek, Ted; Timmermans, Johan; Stuart, Martien A. Cohen; Norde, Willem

    A novel biocompatible and biodegradable microgel system has been developed for controlled uptake and release of especially proteins. It contains TEMPO-oxidized potato starch polymers, which are chemically cross-linked by sodium trimetaphosphate (STMP). Physical chemical properties have been

  6. Preparation and in vitro characterization of slow release testosterone nanocapsules in alginates.

    Science.gov (United States)

    Bhowmik, Benoy Brata; Sa, Biswanath; Mukherjee, Arup

    2006-12-01

    Slow release testosterone-loaded nanocapsules in alginate, biodegradable hydropolymer, were prepared by in situ nanoemulsion-polymer crosslinking approach. Different formulations varying in the drug loading solvent phase were prepared. Four different drug-loading solvents were assayed and the food grade hexane provided nanocapsules testosterone load of 30%. Testosterone loading was confirmed by FT-IR, DSC and quantitated by HPLC. Prepared nanocapsules appeared spherical with a dense drug core in transmission electron microscopy studies. Hydrodynamic diameter of nanocapsules was 34.5 +/- 1.7 nm, with a Gaussian distribution and the zeta potential -5.0 meV. Sustained diffusive drug release was observed in vitro, following zero order kinetics releasing the drug payload over a period of 48 hours. Embedding testosterone in alginate provided sustained release. Different drug loading solvents have distinct influence on drug loading and nanocapsules size distribution. The nanocapsulation technique developed can be a good choice for the development of different sustained steroid hormonal drug carriers.

  7. Synthesis, characterization and drug release properties of 3D chitosan/clinoptilolite biocomposite cryogels.

    Science.gov (United States)

    Dinu, Maria Valentina; Cocarta, Ana Irina; Dragan, Ecaterina Stela

    2016-11-20

    Three-dimensional (3D) biocomposites based on chitosan (CS) and clinoptilolite (CPL) were prepared by cryogelation and their potential application as drug carriers was investigated. Variation of CPL content from 0 to 33wt.% allowed the formation of biocomposites with heterogeneous morphologies consisting of randomly distributed pores. The further increase of CPL content led to ordered porous architectures where parallel pore channels were observed. The CPL content had a strong influence on water uptake, as well as on the cumulative release of diclofenac sodium (DS) and indomethacin (IDM). It was demonstrated that the drug delivery preferentially takes place in phosphate buffer saline (pH 7.4) in comparison to simulated gastric fluid (pH 1.2), where only a reduced drug release was observed. The drug release mechanism dominating these systems is described as a pseudo-Fickian diffusion, but it changes to non-Fickian release when 33wt.% of CPL was entrapped into the CS matrix or when IDM was loaded into biocomposites.

  8. Synthesis, characterization and evaluation of release retardant modified starches of Lagenaria siceraria seeds.

    Science.gov (United States)

    Kulkarni, Sameer D; Sinha, Barij N; Jayaram Kumar, K

    2013-10-01

    Starch isolated from under-utilized seeds of five different cultivars of Lagenaria siceraria (Mol.) standley (Cucurbitaceae) was carboxymethylated. The influence of the degree of substitution (DS) on physicochemical properties and drug release properties of starches was studied. The physicochemical profiles of the derivatives were assessed by means of FT-IR, XRD, SEM, elemental analysis, reaction efficiency, water binding capacity, swelling power, powder characteristics and visual estimation. The highest values of the DS obtained when the carboxymethylation was performed at 45 °C for 4h. Scanning electron microscopy (SEM) showed that after carboxymethylation, the granular appearance of the native starch was distorted. The new bands at 1576.87 cm(-1) and 1423.81 cm(-1) in Fourier transform infrared (FT-IR) indicated that the starch granules were substituted. Wide-angle X-ray diffractometry revealed that crystallinity was reduced significantly after carboxymethylation. Powder studies revealed that these starches possess potential for pharmaceutical applications. The matrix tablets were found to release the drug by Korsmeyer and Peppas kinetics. The carboxymethylated starches with high DS can be used as a drug release retardant in sustained release formulations, as the drug dissolution rate of native starches was significantly lower than the modified starches.

  9. Steps towards the hyperfine splitting measurement of the muonic hydrogen ground state: pulsed muon beam and detection system characterization

    CERN Document Server

    Adamczak, A; Bakalov, D; Baldazzi, G; Bertoni, R; Bonesini, M; Bonvicini, V; Campana, G; Carbone, R; Cervi, T; Chignoli, F; Clemenza, M; Colace, L; Curioni, A; Danailov, M; Danev, P; D'Antone, I; De, A; De, C; De, M; Furini, M; Fuschino, F; Gadejisso-Tossou, K; Guffanti, D; Iaciofano, A; Ishida, K; Iugovaz, D; Labanti, C; Maggi, V; Margotti, A; Marisaldi, M; Mazza, R; Meneghini, S; Menegolli, A; Mocchiutti, E; Moretti, M; Morgante, G; Nardò, R; Nastasi, M; Niemela, J; Previtali, E; Ramponi, R; Rachevski, A; P., L; Rossella, M; Rossi, P L; Somma, F; Stoilov, M; Stoychev, L; Tomaselli, A; Tortora, L; Vacchi, A; Vallazza, E; Zampa, G; Zuffa, M

    2016-01-01

    The high precision measurement of the hyperfine splitting of the muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in the construction of a gas target and of the detectors. In June 2014, the pressurized gas target of the FAMU experiment was exposed to the low energy pulsed muon beam at the RIKEN RAL muon facility. The objectives of the test were the characterization of the target, the hodoscope and the X-ray detectors. The apparatus consisted of a beam hodoscope and X-rays detectors made with high purity Germanium and Lanthanum Bromide crystals. In this paper the experimental setup is described and the results of the detector characterization are presented.

  10. Preparation and characterization of genipin-cross-linked silk fibroin/chitosan sustained-release microspheres.

    Science.gov (United States)

    Zeng, Shuguang; Ye, Manwen; Qiu, Junqi; Fang, Wei; Rong, Mingdeng; Guo, Zehong; Gao, Wenfen

    2015-01-01

    We report the effects of distinct concentrations of genipin and silk fibroin (SF):chitosan (CS) ratios on the formation of SF-CS composite microspheres. We selected microspheres featuring an SF:CS ratio of 1:1, encapsulated various concentrations of bovine serum albumin (BSA), and then compared their encapsulation efficiency and sustained-release rate with those of pure CS microspheres. We determined that the following five groups of microspheres were highly spherical and featured particle sizes ranging from 70 μm to 147 μm: mass ratio of CS:SF =1:0.5, 0.1 g or 0.5 g genipin; CS:SF =1:1, 0.05 g or 1 g genipin; and CS:SF =1:2, 0.5 g genipin. The microspheres prepared using 1:1 CS:SF ratio and 0.05 g genipin in the presence of 10 mg, 20 mg, and 50 mg of BSA exhibited encapsulation efficiencies of 50.16%±4.32%, 56.58%±3.58%, and 42.19%±7.47%, respectively. Fourier-transform infrared spectroscopy (FTIR) results showed that SF and CS were cross-linked and that the α-helices and random coils of SF were converted into β-sheets. BSA did not chemically react with CS or SF. Moreover, thermal gravimetric analysis (TGA) results showed that the melting point of BSA did not change, which confirmed the FTIR results, and X-ray diffraction results showed that BSA was entrapped in microspheres in a noncrystalline form, which further verified the TGA and FTIR data. The sustained-release microspheres prepared in the presence of 10 mg, 20 mg, and 50 mg of BSA burst release 30.79%±3.43%, 34.41%±4.46%, and 41.75%±0.96% of the entrapped BSA on the 1st day and cumulatively released 75.20%±2.52%, 79.16%±4.31%, and 89.04%±4.68% in 21 days, respectively. The pure CS microspheres prepared in the presence of 10 mg of BSA burst release 39.53%±1.76% of BSA on the 1st day and cumulatively released 83.57%±2.33% of the total encapsulated BSA in 21 days. The SF-CS composite microspheres exhibited higher sustained release than did the pure CS microspheres, and thus these composite

  11. Encapsulation and characterization of controlled release flurbiprofen loaded microspheres using beeswax as an encapsulating agent.

    Science.gov (United States)

    Ranjha, Nazar M; Khan, Hafeezullah; Naseem, Shahzad

    2010-05-01

    The aim of the present study was to extend the use of flurbiprofen in clinical settings by avoiding its harmful gastric effects. For this purpose, we designed the controlled release solid lipid flurbiprofen microspheres (SLFM) by emulsion congealing technique. Drug was entrapped into gastro resistant biodegradable beeswax microspheres which were prepared at different drug/beeswax ratios 1:1, 1:2 and 1:3 using gelatin and tween 20 as emulsifying agents. The effect of emulsifiers and the effect drug/beeswax ratios were studied on hydration rate, encapsulating efficiency, micromeritic properties, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (X-RD) analysis and in vitro drug release at pH 1.2 for 2 h and at pH 6.8 for 10 h. SEM revealed that microspheres made with tween 20 were smooth while microspheres made with gelatin showed porous morphology, however, they were all spherical in nature. The practical yield (recovery) showed a dependence on drug-beeswax ratio and it was variable from 53 to 84%. High loading encapsulating efficiency of flurbiprofen from 8 to 94% was achieved. FTIR and DSC analysis confirmed the absence of any drug polymer interaction indicating drug stability during microencapsulation. X-RD of pure flurbiprofen shows sharp peaks, which decreases on encapsulation, indicating decrease in the crystallinity of drug in microspheres. The micromeritic studies confirmed the presence of excellent and good flow properties of microspheres. Entrapment efficiency, morphology, practical yield, hydration rate, flow properties demonstrated their dependence on the HLB value of emulsifiers and emulsifiers with higher HLB were found more appropriate for effective microencapsulation of flurbiprofen. The release kinetics followed zero order mechanism of drug release at pH 6.8. Release pattern depends on the morphology of flurbiprofen microspheres and amount of beeswax used in

  12. Characterization and regulation of (/sup 3/H)-serotonin uptake and release in rodent spinal

    Energy Technology Data Exchange (ETDEWEB)

    Stauderman, K.A.

    1986-01-01

    The uptake and release of (/sup 3/H)-serotonin were investigated in rat spinal cord synaptosomes. In the uptake experiments, sodium-dependent and sodium-independent (/sup 3/H)-serotonin accumulation processes were found. Sodium-dependent (/sup 3/H)-serotonin accumulation was: linear with sodium concentrations up to 180 mM; decreased by disruption of membrane integrity or ionic gradients; associated with purified synaptosomal fractions; and reduced after description of descending serotonergic neurons in the spinal cord. Of the uptake inhibitors tested, the most potent was fluoxetine (IC/sub 50/ 75 nM), followed by desipramine (IC/sub 50/ 430 nM) and nomifensine (IC/sub 50/ 950 nM). The sodium-independent (/sup 3/H)-serotonin accumulation process was insensitive to most treatments and probably represents nonspecific membrane binding. Thus, only sodium-dependent (/sup 3/H)-serotonin uptake represents the uptake process of serotonergic nerve terminals in rat spinal cord homogenates. In the release experiments, K/sup +/-induced release of previously accumulated (/sup 3/H)-serotonin was Ca/sup 2 +/-dependent, and originated from serotonergic synaptosomes. Exogenous serotonin and 5-methyoxy-N,N-dimethyltryptamine inhibited (/sup 3/H)-serotonin release in a concentration-dependent way. Of the antagonists tested, only methiothepin effectively blocked the effect of serotonin. These data support the existence of presynaptic serotonin autoreceptors on serotonergic nerve terminals in the rat spinal cord that act to inhibit a voltage and Ca/sup 2 +/-sensitive process linked to serotonin release. Alteration of spinai cord serotonergic function may therefore be possible by drugs acting on presynaptic serotonin autoreceptors in the spinal cord.

  13. Preparation and characterization of a coacervate extended-release microparticulate delivery system for Lactobacillus rhamnosus

    Directory of Open Access Journals (Sweden)

    Alli SMA

    2011-08-01

    Full Text Available Sk Md Athar Alli Department of Pharmaceutical Technology, Jadavpur University, Kolkata, West Bengal, IndiaBackground: The purpose of this study was to develop a mucoadhesive coacervate microparticulate system to deliver viable Lactobacillus rhamnosus cells into the gut for an extended period of time while maintaining high numbers of viable cells within the formulation throughout its shelf-life and during gastrointestinal transit.Methods: Core coacervate mucoadhesive microparticles of L. rhamnosus were developed using several grades of hypromellose and were subsequently enteric-coated with hypromellose phthalate. Microparticles were evaluated for percent yield, entrapment efficiency, surface morphology, particle size, size distribution, zeta potential, flow properties, in vitro swelling, mucoadhesion properties, in vitro release profile and release kinetics, in vivo probiotic activity, and stability. The values for the kinetic constant and release exponent of model-dependent approaches, the difference factor, similarity factor, and Rescigno indices of model-independent approaches were determined for analyzing in vitro dissolution profiles.Results: Experimental microparticles of formulation batches were of spherical shape with percent yields of 41.24%–58.18%, entrapment efficiency 45.18%–64.16%, mean particle size 33.10–49.62 µm, and zeta potential around -11.5 mV, confirming adequate stability of L. rhamnosus at room temperature. The in vitro L. rhamnosus release profile follows zero-order kinetics and depends on the grade of hypromellose and the L. rhamnosus to hypromellose ratio.Conclusion: Microparticles delivered L. rhamnosus in simulated intestinal conditions for an extended period, following zero-order kinetics, and exhibited appreciable mucoadhesion in simulated intestinal conditions.Keywords: Lactobacillus rhamnosus, mucoadhesive, microparticles, extended-release, intestine

  14. Magnetic glass ceramics for sustained 5-fluorouracil delivery: Characterization and evaluation of drug release kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Hameed, S.A.M., E-mail: Salwa_NRC@hotmail.com [Glass Research Department, National Research Center, Dokki, ElBehoos St., Cairo 12311 (Egypt); El-Kady, A.M. [Biomaterial Department, National Research Center, Dokki, ElBehoos St., Cairo 12311 (Egypt); Marzouk, M.A. [Glass Research Department, National Research Center, Dokki, ElBehoos St., Cairo 12311 (Egypt)

    2014-11-01

    In the present study, magnetic glass ceramics in the system Fe{sub 2}O{sub 3} ∙ TiO{sub 2} ∙ P{sub 2}O{sub 5} ∙ SiO{sub 2} ∙ MO (M = Mg, Ca, Mn, Cu, Zn or Ce) are prepared. The effect of adding different cations on the thermal behavior, developed phases, microstructure and magnetic properties is studied using differental thermal analysis (DTA), X-ray diffraction analysis (XRD), transmission electron microscope (TEM), FT-infrared transmission (FT-IR) and vibrating sample magnetometer (VSM) respectively. The magnetic glass ceramics are tested as delivery systems for 5-fluorouracil. Modeling and analysis of release kinetics are addressed. The application of Higuchi square root of time model and the first order release model indicated that, 5-FU is released by diffusion controlled mechanisms, and that its released rate depends greatly on the concentration of loaded drug during the loading stage. The obtained results suggested that, the prepared magnetic glass ceramics can be used for cancer treatment by hyperthermia and/or by localized delivery of therapeutic doses of 5-fluorouracil. - Highlights: • Preparation of magnetic glass ceramics in the system Fe{sub 2}O{sub 3} ∙ TiO{sub 2} ∙ P{sub 2}O{sub 5} ∙ SiO{sub 2} ∙ MO • The magnetic glass ceramics were tested as delivery systems for 5-fluorouracil. • Drug release profiles follow Higuchi square root of time and first order model.

  15. Study of a controlled release polymeric system based on Pluronic P123: Spectroscopic characterization and theoretical model approach

    Science.gov (United States)

    Arroyo, E.; Luque, P. A.; Cosio, M.; Soto, C.; Villarreal, R.; Nava, O.; Olivas, A.

    2017-06-01

    This work reports the profiles of drug release systems based on different polymers for the potential use as a skin anti-inflammatory. The materials used for the encapsulation of indomethacin were Pluronic P123 with various combinations of poly-ethylene-glycol and poly-N-vinyl pyrrolidone. These systems were characterized via Fourier transform infrared spectrometry and high resolution transmission electron microscopy. The morphology showed the treated polymers as spheres. Drug loadings were carried out via the absorption in solution method; this load was of a 1:10 wt ratio indomethacin to polymers. Drug release tests were performed via the dialysis method pH 7.2 phosphate buffered saline at 32 °C. The drug concentration was determined via UV-Vis spectroscopy, and additionally, a theoretical model was developed based on diffusion equations to describe the phenomenon. Comparison between the experimental results and theory was close to 5%.

  16. Using Locally Generated Magnetic Indices to Characterize the Ionosphere From Magnetic Data Acquisition System (Magdas Ground Based Observatories in Nigeria.

    Directory of Open Access Journals (Sweden)

    U.C. Rabiu

    2013-06-01

    Full Text Available This work presents an attempt to establish a baseline for geomagnetic indices inNigeria. This is particularly very crucial since these indices give indications of theseverity of magnetic fluctuations, and hence the level of disturbances in theionosphere. K (an index which measures the magnetic perturbations of theplanetary field and A (a linear measure of the Earth's field that provides a dailyaverage level for geomagnetic activity geomagnetic indices were generated locallyfrom geomagnetic data obtained using ground based MAGDAS magnetometerslocated at Abuja (9 ̊ 40’N, 7 ̊ 29’E, Ilorin (8 ̊30’N, 4 ̊33’E and Lagos (6 ̊27’N,3 ̊23’E in Nigeria using Computer-based derivation. The indices generated wereused to characterize the ionosphere over the Magdas magnetometer Nigerianetwork stations. Results obtained showed average K values of 3.5 (ABU, 4.60(LAG and 4.13 (ILR, the ionosphere over the three stations was found to berelatively active (4.08 thus setting the baseline for characterizing the ionosphereover Nigeria from ground based magnetometers.

  17. Characterization of ground-water flow between the Canisteo Mine Pit and surrounding aquifers, Mesabi Iron Range, Minnesota

    Science.gov (United States)

    Jones, Perry M.

    2002-01-01

    The U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, conducted a study to characterize ground-water flow conditions between the Canisteo Mine Pit, Bovey, Minnesota, and surrounding aquifers following mine abandonment. The objective of the study was to estimate the amount of steady-state, ground-water flow between the Canisteo Mine Pit and surrounding aquifers at pit water-level altitudes below the level at which surface-water discharge from the pit may occur. Single-well hydraulic tests and stream-hydrograph analyses were conducted to estimate horizontal hydraulic conductivities and ground-water recharge rates, respectively, for glacial aquifers surrounding the mine pit. Average hydraulic conductivity values ranged from 0.05 to 5.0 ft/day for sands and clays and from 0.01 to 121 ft/day for coarse sands, gravels, and boulders. The 15-year averages for the estimated annual recharge using the winter records and the entire years of record for defining baseflow recession rates were 7.07 and 7.58 in., respectively. These recharge estimates accounted for 25 and 27 percent, respectively, of the average annual precipitation for the 1968-82 streamflow monitoring period. Ground-water flow rates into and out of the mine pit were estimated using a calibrated steady-state, ground-water flow model simulating an area of approximately 75 mi2 surrounding the mine pit. The model residuals, or difference between simulated and measured water levels, for 15 monitoring wells adjacent to the mine pit varied between +28.65 and –3.78 ft. The best-match simulated water levels were within 4 ft of measured water levels for 9 of the 15 wells, and within 2 ft for 4 of the wells. The simulated net ground-water flow into the Canisteo Mine Pit was +1.34 ft3/s, and the net ground-water flow calculated from pit water levels measured between July 5, 1999 and February 25, 2001 was +5.4 ft3/s. Simulated water levels and ground-water flow to and from the mine

  18. Ciprofloxacin Loaded Bovine Serum Albumin Microspheres: Prepa-ration and Drug Release Characterization In Vitro

    Institute of Scientific and Technical Information of China (English)

    LiFengqian; HuJinhong; LuBin; ZhuQuangang; SunHuajun

    2001-01-01

    Ciprofloxacin loaded microspheres were prepared by spray drying technique, with bovine serum albumin as the natural biodegradable wall materials. The obtained microspheres, using aqueous system, were organic solvent-free. The diameters of the spherical microspheres were in the range of 1-5 1:4. The drug entrapment of microspheres, formulated with different ciprofloxacin/albumin ratios as 1:1, 1:2 and 1:4, were 46.93%, 32.96% and 20.56% (n=3). And the encapsulation efflciencies for ciprofloxacin during spray drying were higher than 90%. Thermal denaturation programs at different temperatures (100-120℃) for different time intervals (3-6-12 h) were further processed to stabilize the spray-dried microspheres. The higher the extent for thermal denaturation, the slower the rate of ciprofloxacin released from microspheres in vitro. So the release rate of ciprofloxacin from microspheres can be controlled by modifing the conditions of thermal denaturation.

  19. Encapsulation of naproxen in nanostructured system: structural characterization and in vitro release studies

    Directory of Open Access Journals (Sweden)

    Vanessa Azevedo de Mello

    2011-01-01

    Full Text Available Nanoparticles were produced by solvent emulsification evaporation method with the following characteristics: nanometric size (238 ± 3 nm, narrow polydispersity index (0.11, negative zeta potential (-15.1 mV, good yield of the process (73 ± 1.5%, excellent encapsulation efficiency (81.3 ± 4.2% and spherical shape. X-rays diffraction demonstrated the loss of drug crystallinity after encapsulation; however, the profile of the diffractograms of the poly-ε-caprolactone (PCL nanoparticles was kept. Differential scanning calorimetry thermograms, correspondingly, exhibited the loss of drug melting peak and the increasing of the melting point of the PCL nanoparticles, evidencing an interaction drug-polymer. Naproxen release was low and sustained obeying the Higuchi´s kinetic. The results show that nanoparticles are promising sustained release system to the naproxen.

  20. Preparation and Characterization of Keratin Blended Films using Biopolymers for Drug Controlled Release Application

    Directory of Open Access Journals (Sweden)

    Ansaya Thonpho

    2016-08-01

    Full Text Available Keratin solution was separately blended with collagen, gelatin, sericin and starch for films preparation. All the blended films had smooth surfaces without phase separation, except the keratin/starch blend film. The native keratin film showed small particles embedded in all the film surfaces that resulted in them being rough. The structure of the native keratin film changed from beta-sheet to random coil at high blend ratio of other substances. This result increased the dissolution of the films especially the keratin/starch blend. The results relate directly to the decreased thermal stability of this film. However, the changes in structure did not affect the chlorhexidine release pattern. It is possible that the interaction between the drug and blending substances, and the substances to water molecules are the main factor influencing the drug release pattern from the films.

  1. Characterization of a novel subtype of hippocampal interneurons that express corticotropin-releasing hormone.

    Science.gov (United States)

    Hooper, Andrew; Maguire, Jamie

    2016-01-01

    A subset of corticotropin-releasing hormone (CRH) neurons was previously identified in the hippocampus with unknown function. Here we demonstrate that hippocampal CRH neurons represent a novel subtype of interneurons in the hippocampus, exhibiting unique morphology, electrophysiological properties, molecular markers, and connectivity. This subset of hippocampal CRH neurons in the mouse reside in the CA1 pyramidal cell layer and tract tracing studies using AAV-Flex-ChR2-tdTomato reveal dense back-projections of these neurons onto principal neurons in the CA3 region of the hippocampus. These hippocampal CRH neurons express both GABA and GAD67 and using in vitro optogenetic techniques, we demonstrate that these neurons make functional connections and release GABA onto CA3 principal neurons. The location, morphology, and importantly the functional connectivity of these neurons demonstrate that hippocampal CRH neurons represent a unique subtype of hippocampal interneurons. The connectivity of these neurons has significant implications for hippocampal function.

  2. Preparation, characterization, and in vitro release study of albendazole-encapsulated nanosize liposomes

    OpenAIRE

    Panwar, Preety; Pandey, Bhumika; P C Lakhera; Singh, K. P.

    2010-01-01

    The purpose of the present study was to formulate effective and controlled release albendazole liposomal formulations. Albendazole, a hydrophobic drug used for the treatment of hydatid cysts, was encapsulated in nanosize liposomes. Rapid evaporation method was used for the preparation of albendazole-encapsulated conventional and PEGylated liposomes consisting of egg phosphatidylcholine (PC) and cholesterol (CH) in the molar ratios of (6:4) and PC:CH: polyethylene glycol (PEG) (5:4:1), respect...

  3. Preparation, characterization, and in vitro release study of albendazole-encapsulated nanosize liposomes

    OpenAIRE

    Singh, K. P.

    2010-01-01

    Preety Panwar1, Bhumika Pandey1, P C Lakhera2, K P Singh11Biophysics and Nanotechnology Research Laboratory, CBSH, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India; 2Department of Biotechnology, H.N.B. Garhwal University, Srinagar Garhwal, Uttarakhand, IndiaAbstract: The purpose of the present study was to formulate effective and controlled release albendazole liposomal formulations. Albendazole, a hydrophobic drug used for the treatment of hydatid cysts, was ...

  4. Drug release characterization and preparation of Ca-Alginate microparticle drug carrier using membrane emulsification method

    Energy Technology Data Exchange (ETDEWEB)

    You, Jin Oh; Park, Seong Bae; Park, Ham Yong; Haam, Seung Joo; Kim, Jung Hyun; Kim, Woo Sik [Dept. of Chemical Engineering, Yonsei University, Seoul (Korea)

    1999-10-01

    Conventional alginate bead has been limited to be used as a drug carrier because of its large size. To overcome the disadvantages of conventional large-size alginate drug beads, Ca-alginate microparticles were prepared using membrane emulsification method controlled with the sodium alginate concentration and the pressure of reactor. The optimal monodispersed microparticles were obtained with the concentration of 2 wt % alginate solution and the pressure of 0.4*10{sup 5} Pa. The mean size of our prepared microparticles was about 4 {gamma}m. As the drug solutions, lidocaine{center_dot}HCI(cationic), sodium salicylate(anionic) and 4-acetamidophenol(nonionic) were selected. These three different drugs were loaded in the drug carrier of prepared alginate microparticles. Drug releases were performed in the sodium phosphate buffers of pH 2 and pH 7 and ionic strength of 0.2. The release behavior with the variation of drug charge shoed that of the cationic drug release was retarded more than anionic one due to the ionic interaction between carboxyl group of alginates and positive charge of cationic drug. >From the comparison experiments of the buffers of pH 2 and pH 7, the release was much retarded at pH 2 buffer due to the ionic repulsive force or ionic attractive force between the carboxyl group and the hydroxy or sodium ion in the buffer. Conclusively, the usage of small-size pH sensitive microparticle as a drug carrier has a high potential for the application of drug delivery systems. 19 refs., 9 figs.

  5. Characterization of Site for Installing Open Loop Ground Source Heat Pump System

    Science.gov (United States)

    Yun, S. W.; Park, Y.; Lee, J. Y.; Yi, M. J.; Cha, J. H.

    2014-12-01

    This study was conducted to understand hydrogeological properties of site where open loop ground source heat pump system will be installed and operated. Groundwater level and water temperature were hourly measured at the well developed for usage of open loop ground source heat pump system from 11 October 2013 to 8 January 2014. Groundwater was sampled in January and August 2013 and its chemical and isotopic compositions were analyzed. The bedrock of study area is the Jurassic granodiorite that mainly consists of quartz (27.9 to 46.8%), plagioclase (26.0 to 45.5%), and alkali feldspar (9.5 to 18.7%). The groundwater level ranged from 68.30 to 68.94 m (above mean sea level). Recharge rate was estimated using modified watertable fluctuation method and the recharge ratios was 9.1%. The water temperature ranged from 14.8 to 15.0oC. The vertical Increase rates of water temperature were 1.91 to 1.94/100 m. The water temperature showed the significant seasonal variation above 50 m depth, but had constant value below 50 m depth. Therefore, heat energy of the groundwater can be used securely in open loop ground source heat pump system. Electrical conductivity ranged from 120 to 320 µS/cm in dry season and from 133 to 310 µS/cm in wet season. The electrical conductivity gradually decreased with depth. In particular, electrical conductivity in approximately 30 m depth decreased dramatically (287 to 249 µS/cm) in wet season. The groundwater was Ca-HCO3 type. The concentrations of dissolved components did not show the vertically significant variations from 0 to 250 m depth. The δ18O and δD ranged from -9.5 to -9.4‰ and from -69 to -68‰. This work is supported by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No.20123040110010).

  6. Granulometric characterization of airborne particulate release during spray application of nanoparticle-doped coatings

    Science.gov (United States)

    Göhler, Daniel; Stintz, Michael

    2014-08-01

    Airborne particle release during the spray application of coatings was analyzed in the nanometre and micrometre size range. In order to represent realistic conditions of domestic and handcraft use, the spray application was performed using two types of commercial propellant spray cans and a manual gravity spray gun. Four different types of coatings doped with three kinds of metal-oxide tracer nanoparticle additives (TNPA) were analyzed. Depending on the used coating and the kind of spray unit, particulate release numbers between 5 × 108 and 3 × 1010 particles per gram ejection mass were determined in the dried spray aerosols. The nanoparticulate fraction amounted values between 10 and 60 no%. The comparison between nanoparticle-doped coatings with non-doped ones showed no TNPA-attributed differences in both the macroscopic spray process characteristics and the particle release numbers. SEM, TEM and EDX-analyzes showed that the spray aerosols were composed of particles made up solely from matrix material and sheathed pigments, fillers and TNPAs. Isolated ZnO- or Fe2O3-TNPAs could not be observed.

  7. Characterization of chlorhexidine-releasing, fast-setting, brushite bone cements.

    Science.gov (United States)

    Young, Anne M; Ng, Poon Yun J; Gbureck, Uwe; Nazhat, Showan N; Barralet, Jake E; Hofmann, Michael P

    2008-07-01

    The effect of antibacterial chlorhexidine diacetate powder (CHX) on the setting kinetics of a brushite-forming beta-tricalcium phosphate/monocalcium phosphate monohydrate (beta-TCP/MCPM) cement was monitored using attenuated total reflection Fourier transform infrared spectroscopy. The final composition of the set cement with up to 12 wt.% CHX content before and after submersion in water for 24h, the kinetics of chlorhexidine release and the total sample mass change in water over four weeks was monitored using Raman mapping, UV spectroscopy and gravimetry, respectively. Below 9 wt.%, CHX content had no significant effect on brushite formation rate at 37 degrees C, but at 12 wt.% the half-life of the reaction decreased by one-third. Raman mapping confirmed that brushite was the main inorganic component of the set cements irrespective of CHX content, both before and after submersion in water. The CHX could be detected largely as discrete solid particles but could also be observed partially dispersed throughout the pores of the set cement. The percentage of CHX release was found to follow Fick's law of diffusion, being independent of its initial concentration, proportional to the square root of time and, with 1mm thick specimens, 60% was released at 24h. Total set cement mass loss rate was not significantly affected by CHX content. On average, cements exhibited a loss of 7 wt.% assigned largely to surface phosphate particle loss within the initial 8h followed by 0.36 wt.% per day.

  8. Development of ligustrazine hydrochloride carboxymethyl chitosan and collagen microspheres: Formulation optimization, characterization, and vitro release.

    Science.gov (United States)

    Lin, Qiang; Huo, Qing; Qin, Yingzhe; Zhao, Zhuo; Tao, Fengyun

    2017-01-02

    This study investigates the preparation of ligustrazine hydrochloride carboxymethyl chitosan and collagen microspheres. This experiment investigates effects of the ratio of carboxymethyl chitosan and collagen blend, water to oil ratio, stirring speed, and other factors on the microsphere properties. The experiment had the following conditions: a 1:2 proportion of carboxymethyl chitosan and collagen, a 1:2 proportion of drugs and materials, a 5:1 proportion of oil phase and water phase, 0.5% of span80, a 600r/min stirring speed, 3 ml of a cross-linking agent, 3 h of cross-linking curing, 1.25 ± 0.05 mm diameter LTH microcapsules, a 54.08% envelop rate, and a 14.16% carrier rate. The microspheres release rate reached 66% within 1 h, then steadily released within 5 h in vitro. The experimental results showed that the ligustrazine hydrochloride microsphere production process was stable and exhibited a good release effect compared with other ligustrazine hydrochloride tablets and pills.

  9. Rheological characterization of xanthan gum and hydroxypropylmethyl cellulose with respect to controlled-release drug delivery.

    Science.gov (United States)

    Talukdar, M M; Vinckier, I; Moldenaers, P; Kinget, R

    1996-05-01

    It has been observed previously that xanthan gum (XG) and hydroxypropylmethyl cellulose (HPMC) show different drug release behavior. In order to clarify these findings, the rheological properties of both polymers have been determined by oscillatory as well as by steady shear measurements. Aqueous solutions of 4 and 7% (w/w) polymer have been used to simulate the outer surface of a hydrated tablet. The dynamic moduli, i.e., storage modulus (G') and loss modulus (G") of the two polymers have been determined in pure water and USP phosphate buffer pH 7.4 at different dilutions. In this concentration range XG solution exhibits "gel-like" behavior, while HPMC behaves as a typical polymer solution. These findings are quite consistent with the reported higher ability of XG matrices to retard drug release than HPMC matrices for controlled-release formulation. The effects of differences in drug solubility and acidity, as well as the addition of lactose, and of the ionic strength of the medium on the rheological properties of XG and HPMC solutions have been studied in detail. Among these parameters, only the salt concentration exerts an enhancing effect on both moduli of XG, while no detectable influence on HPMC solution could be observed.

  10. Granulometric characterization of airborne particulate release during spray application of nanoparticle-doped coatings.

    Science.gov (United States)

    Göhler, Daniel; Stintz, Michael

    2014-01-01

    Airborne particle release during the spray application of coatings was analyzed in the nanometre and micrometre size range. In order to represent realistic conditions of domestic and handcraft use, the spray application was performed using two types of commercial propellant spray cans and a manual gravity spray gun. Four different types of coatings doped with three kinds of metal-oxide tracer nanoparticle additives (TNPA) were analyzed. Depending on the used coating and the kind of spray unit, particulate release numbers between 5 × 10(8) and 3 × 10(10) particles per gram ejection mass were determined in the dried spray aerosols. The nanoparticulate fraction amounted values between 10 and 60 no%. The comparison between nanoparticle-doped coatings with non-doped ones showed no TNPA-attributed differences in both the macroscopic spray process characteristics and the particle release numbers. SEM, TEM and EDX-analyzes showed that the spray aerosols were composed of particles made up solely from matrix material and sheathed pigments, fillers and TNPAs. Isolated ZnO- or Fe2O3-TNPAs could not be observed.

  11. An ultra-wideband dielectric material characterization method using grounded coplanar waveguide and genetic algorithm optimization

    Science.gov (United States)

    Hadjloum, Massinissa; El Gibari, Mohammed; Li, Hongwu; Daryoush, Afshin S.

    2015-10-01

    An ultra-wideband complex permittivity extraction method is reported here using numerical fitting of scattering parameters to measured results. A grounded coplanar waveguide transmission line is realized on an unknown dielectric material, whose dielectric constant and loss tangent are extracted by the best fitting of the simulated magnitude, |S21|, and phase, ϕ21, of forward scattering parameter using an electromagnetic full-wave simulator (high frequency structure simulator) to the measured results. The genetic algorithm is employed for optimum rapid extraction, where errors between the numerically simulated and measured S21 (|S21| and ϕ21) are minimized in an iterative manner. As long as the convergence criterion is not satisfied, modifications to dielectric properties are made with this genetic algorithm implemented in Matlab. Feasibility of this extraction technique is validated on benzocyclobutane polymer from 10 MHz to 40 GHz.

  12. Soil moisture characterization of the Valencia anchor station. Ground, aircraft measurements and simulations

    DEFF Research Database (Denmark)

    Lopez-Baeza, E; Antolin, M C; Balling, Jan E.

    2009-01-01

    In the framework of ESA SMOS Mission, the Valencia Anchor Station (VAS) has been selected as a core validation site. Its reasonable homogeneous characteristics make it appropriate to undertake the validation of SMOS Level 2 land products before attempting other more complex areas. Close to SMOS....... For the rehearsal activity which successfully took place in April - May 2008, a control area of 10 × 10 km2 was chosen at the VAS study area where a network of ground soil moisture (SM) measuring stations is being set up based on an original definition of homogeneous physio-hydrological units attending to climatic...... of the following instruments: (i) L-band EMIRAD radiometer (Technical University of Denmark, TUD), (ii) L-band HUT-2D imaging interferometric radiometer (TKK), (iii) PARIS GPS reflectrometry system (Institute for Space Studies of Catalonia, IEEC), (iv) IR sensor (Finnish Institute of Maritime Research, FIMR...

  13. Ground based experiments on the growth and characterization of L-Arginine Phosphate (LAP) crystals

    Science.gov (United States)

    Rao, S. M.; Cao, C.; Batra, A. K.; Lal, R. B.; Mookherji, T. K.

    1991-01-01

    L-Arginine Phosphate (LAP) is a new nonlinear optical material with higher efficiency for harmonic generation compared to KDP. Crystals of LAP were grown in the laboratory from supersaturated solutions by temperature lowering technique. Investigations revealed the presence of large dislocation densities inside the crystals which are observed to produce refractive index changes causing damage at high laser powers. This is a result of the convection during crystal growth from supersaturated solutions. It is proposed to grow these crystals in a diffusion controlled growth condition under microgravity environment and compare the crystals grown in space with those grown on ground. Physical properties of the solutions needed for modelling of crystal growth are also presented.

  14. Characterization of polysaccharides extracted from spent coffee grounds by alkali pretreatment.

    Science.gov (United States)

    Ballesteros, Lina F; Cerqueira, Miguel A; Teixeira, José A; Mussatto, Solange I

    2015-01-01

    Spent coffee grounds (SCG), obtained during the processing of coffee powder with hot water to make soluble coffee, are the main coffee industry residues and retain approximately seventy percent of the polysaccharides present in the roasted coffee beans. The purpose of this study was to extract polysaccharides from SCG by using an alkali pretreatment with sodium hydroxide at 25°C, and determine the chemical composition, as well as the antioxidant and antimicrobial properties of the extracted polysaccharides. Galactose (60.27%mol) was the dominant sugar in the recovered polysaccharides, followed by arabinose (19.93%mol), glucose (15.37%mol) and mannose (4.43%mol). SCG polysaccharides were thermostable, and presented a typical carbohydrate pattern. Additionally, they showed good antioxidant activity through different methods and presented high antimicrobial percent inhibition against Phoma violacea and Cladosporium cladosporioides (41.27% and 54.60%, respectively). These findings allow identifying possible applications for these polysaccharides in the food industry.

  15. Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment

    Science.gov (United States)

    Brito, J.; Rizzo, L. V.; Morgan, W. T.; Coe, H.; Johnson, B.; Haywood, J.; Longo, K.; Freitas, S.; Andreae, M. O.; Artaxo, P.

    2014-11-01

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of biomass burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional biomass burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted biomass burning plumes. Aerosol number concentrations ranged from ~1000 cm-3 to peaks of up to 35 000 cm-3 (during biomass burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m-3 and peak concentrations close to 100 μg m-3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m-3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m-3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m-3, with an average concentration of 1.3 μg m-3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of biomass burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0

  16. Ground based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA field experiment

    Directory of Open Access Journals (Sweden)

    J. Brito

    2014-05-01

    Full Text Available This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the Southwestern part of the Brazilian Amazon forest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA field experiment, which consisted of a combination of aircraft and ground based measurements over Brazil, aiming to investigate the impacts of biomass burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional biomass burning pollution (average CO mixing ratio of 0.6 ppm, occasionally superimposed by intense (up to 2 ppm of CO, freshly emitted biomass burning plumes. Aerosol number concentrations ranged from ∼1000 cm−3 to peaks of up to 35 000 cm−3 during biomass burning (BB events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed on average at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent Black Carbon (BCe ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe, among the highest values described in the literature. We examined the ageing of Biomass Burning Organic Aerosol (BBOA using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol

  17. Characterizing the Vertical Distribution of Aerosols using Ground-based Multiwavelength Lidar Data

    Science.gov (United States)

    Ferrare, R. A.; Thorsen, T. J.; Clayton, M.; Mueller, D.; Chemyakin, E.; Burton, S. P.; Goldsmith, J.; Holz, R.; Kuehn, R.; Eloranta, E. W.; Marais, W.; Newsom, R. K.; Liu, X.; Sawamura, P.; Holben, B. N.; Hostetler, C. A.

    2016-12-01

    Observations of aerosol optical and microphysical properties are critical for developing and evaluating aerosol transport model parameterizations and assessing global aerosol-radiation impacts on climate. During the Combined HSRL And Raman lidar Measurement Study (CHARMS), we investigated the synergistic use of ground-based Raman lidar and High Spectral Resolution Lidar (HSRL) measurements to retrieve aerosol properties aloft. Continuous (24/7) operation of these co-located lidars during the ten-week CHARMS mission (mid-July through September 2015) allowed the acquisition of a unique, multiwavelength ground-based lidar dataset for studying aerosol properties above the Southern Great Plains (SGP) site. The ARM Raman lidar measured profiles of aerosol backscatter, extinction and depolarization at 355 nm as well as profiles of water vapor mixing ratio and temperature. The University of Wisconsin HSRL simultaneously measured profiles of aerosol backscatter, extinction and depolarization at 532 nm and aerosol backscatter at 1064 nm. Recent advances in both lidar retrieval theory and algorithm development demonstrate that vertically-resolved retrievals using such multiwavelength lidar measurements of aerosol backscatter and extinction can help constrain both the aerosol optical (e.g. complex refractive index, scattering, etc.) and microphysical properties (e.g. effective radius, concentrations) as well as provide qualitative aerosol classification. Based on this work, the NASA Langley Research Center (LaRC) HSRL group developed automated algorithms for classifying and retrieving aerosol optical and microphysical properties, demonstrated these retrievals using data from the unique NASA/LaRC airborne multiwavelength HSRL-2 system, and validated the results using coincident airborne in situ data. We apply these algorithms to the CHARMS multiwavelength (Raman+HSRL) lidar dataset to retrieve aerosol properties above the SGP site. We present some profiles of aerosol effective

  18. Characterization of vapor phase mercury released from concrete processing with baghouse filter dust added cement.

    Science.gov (United States)

    Wang, Jun; Hayes, Josh; Wu, Chang-Yu; Townsend, Timothy; Schert, John; Vinson, Tim; Deliz, Katherine; Bonzongo, Jean-Claude

    2014-02-18

    The fate of mercury (Hg) in cement processing and products has drawn intense attention due to its contribution to the ambient emission inventory. Feeding Hg-loaded coal fly ash to the cement kiln introduces additional Hg into the kiln's baghouse filter dust (BFD), and the practice of replacing 5% of cement with the Hg-loaded BFD by cement plants has recently raised environmental and occupational health concerns. The objective of this study was to determine Hg concentration and speciation in BFD as well as to investigate the release of vapor phase Hg from storing and processing BFD-added cement. The results showed that Hg content in the BFD from different seasons ranged from 0.91-1.44 mg/kg (ppm), with 62-73% as soluble inorganic Hg, while Hg in the other concrete constituents were 1-3 orders of magnitude lower than the BFD. Up to 21% of Hg loss was observed in the time-series study while storing the BFD in the open environment by the end of the seventh day. Real-time monitoring in the bench system indicated that high temperature and moisture can facilitate Hg release at the early stage. Ontario Hydro (OH) traps showed that total Hg emission from BFD is dictated by the air exchange surface area. In the bench simulation of concrete processing, only 0.4-0.5% of Hg escaped from mixing and curing BFD-added cement. A follow-up headspace study did not detect Hg release in the following 7 days. In summary, replacing 5% of cement with the BFD investigated in this study has minimal occupational health concerns for concrete workers, and proper storing and mixing of BFD with cement can minimize Hg emission burden for the cement plant.

  19. Silver speciation and characterization of nanoparticles released from plastic food containers by single particle ICPMS.

    Science.gov (United States)

    Ramos, K; Gómez-Gómez, M M; Cámara, C; Ramos, L

    2016-05-01

    Silver migration from a commercial baby feeding bottle and a food box containing AgNPs, as confirmed by SEM-EDX analysis, was evaluated using food simulant solutions [i.e., water, 3% (v/v) acetic acid, and 10% and 90% (v/v) ethanol]. Silver release was investigated at temperatures in the 20-70°C range using contact times of up to 10 days. Migration of silver from the food box was in all cases 2 to 3 orders of magnitude higher than that observed for the baby bottle, although the total silver content in the original box material was half of that found in the baby bottle. As expected, for both food containers, silver migration depended on both the nature of the tested solution and the applied conditions. The highest release was observed for 3% acetic acid at 70°C for 2h, corresponding to 62ngdm(2) and 1887ngdm(-2) of silver for the baby bottle and the food box, respectively. Single particle-inductively coupled plasma mass spectrometry (SP-ICPMS) was used to characterise and quantify AgNPs in the food simulants extracts. Sample preparation was optimized to preserve AgNPs integrity. The experimental parameters affecting AgNPs detection, sizing and quantification by SP-ICPMS were also optimised. Analyses of water and acidic extracts revealed the presence of both dissolved silver and AgNPs. Small AgNPs (in the 18-30nm range) and particle number concentrations within the 4-1510 10(6)L(-1) range were detected, corresponding to only 0.1-8.6% of the total silver released from these materials. The only exception was AgNPs migrated into water at 40°C and 70°C from the food box, which accounted for as much as 34% and 69% of the total silver content, respectively.

  20. Characterizing Geothermal Surface Manifestation Based on Multivariate Geostatistics of Ground Measurements Data

    Science.gov (United States)

    Ishaq; Nur Heriawan, Mohamad; Saepuloh, Asep

    2016-09-01

    Mt. Wayang Windu is one of geothermal field located in West Java, Indonesia. The characterization of steam spots at surface manifestation zones based on the soil physical measurements of the area is presented in this study. The multivariate geostatistical methods incorporating the soil physical parameter data were used to characterize the zonation of geothermal surface manifestations. The purpose of this study is to evaluate the performance of spatial estimation method of multivariate geostatistics using Ordinary Cokriging (COK) to characterize the physical properties of geothermal surface manifestations at Mt. Wayang Windu. The COK method was selected because this method is favorable when the secondary variables has more number than the primary variables. There are four soil physical parameters used as the basis of COK method, i.e. Electrical Conductivity, Susceptibility, pH, and Temperature. The parameters were measured directly at and around geothermal surface manifestations including hot springs, fumaroles, and craters. Each location of surface manifestations was measured about 30 points with 30 x 30 m grids. The measurement results were analyzed by descriptive statistics to identify at the nature of data. The correlation among variables was analyzed using linear regression. When the correlation coefficient among variables is higher, the estimation results is expected to have better Linear Coregionalization Model (LCM). LCM was used to analyze the spatial correlation of each variable based on their variogram and cross-variogram model. In oder to evaluate the performance of multivariate geostatistical using COK method, a Root Mean Square Error (RMSE) was performed. Estimation result using COK method is well applicable for characterizing the surface physics parameters of radar images data.

  1. Detection and characterization of nanomaterials released in low concentrations during multi-walled carbon nanotube spraying process in a cleanroom.

    Science.gov (United States)

    Ji, Jun Ho; Woo, Daekwang; Lee, Seung-Bok; Kim, Taesung; Kim, Duckjong; Kim, Jae-Hyun; Bae, Gwi-Nam

    2013-12-01

    Release of nanomaterials was assessed in a cleanroom workplace designed for the handling of multi-walled carbon nanotubes. During the process, the nanotubes were sprayed in a chamber fitted with an exhaust duct system. The front door of the spraying chamber was completely closed, but rear end of the chamber was partially open. Throughout a series of spray processes, three detectors - an optical particle counter, a nanoparticle aerosol monitor, and an aethalometer - counted and characterized particles escaping the chamber. Concentrations of particle surface area and black carbon emitted by the spraying were assessed assuming zero background aerosol concentration in the cleanroom. Very low concentrations of black carbon, 0.4 μg/m(3), were observed. In conclusion, in a cleanroom, low concentrations of nanomaterials were detected to be emitted from a spraying chamber into the workplace. The level of particles reaching the workplace was sufficiently low to have made their detection difficult in a normal environment. Both target nanomaterial and non-intended incidental nanomaterials were released during spraying. Despite the use of exhaust duct system in the process chamber, workers would be exposed to some particles if the chamber were partially open. The exhaust duct system was not enough to remove all the particles released in the chamber.

  2. Synthesis and characterization of a novel controlled release zinc oxide/gentamicin-chitosan composite with potential applications in wounds care.

    Science.gov (United States)

    Vasile, Bogdan Stefan; Oprea, Ovidiu; Voicu, Georgeta; Ficai, Anton; Andronescu, Ecaterina; Teodorescu, Andrei; Holban, Alina

    2014-03-25

    Freshly prepared ZnO nanoparticles were incorporated into a chitosan solution in weight ratios ranging from 1:1 to 12:1. Starting from the ratio of 3:1 the chitosan solution was transformed into a gel with a high consistency, which incorporates 15mL water for only 0.1g solid substance. The powders obtained after drying the gel were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermal analysis (TG-DSC). The electronic (UV-vis), infrared (FTIR) and photoluminescence (PL) spectra were also recorded. ZnO particles were coated with gentamicin and incorporated into the chitosan matrix, to yield a ZnO/gentamicin-chitosan gel. The release rate of gentamicin was monitored photometrically. This ZnO/gentamicin-chitosan gel proved great antimicrobial properties, inhibiting Staphylococcus aureus and Pseudomonas aeruginosa growth in both planktonic and surface-attached conditions. The results indicate that the obtained composite can be used in cutaneous healing for developing improved wound dressings, which combine the antibacterial activity of all three components with the controlled release of the antibiotic. This wound dressing maintains a moist environment at the wound interface, providing a cooling sensation and soothing effect, while slowly releasing the antibiotic. The system is fully scalable to any other soluble drug, as the entire solution remains trapped in the ZnO-chitosan gel.

  3. Factorial design based preparation, optimization, characterization and in vitro drug release studies of olanzapine loaded PLGA nanoparticles

    Science.gov (United States)

    Bohrey, Sarvesh; Chourasiya, Vibha; Pandey, Archna

    2016-12-01

    The objective of the present work was to develop and optimize olanzapine loaded polymeric nanoparticles using a factorial design. The presented work developed and optimized olanzapine loaded polymeric nanoparticles by using a 33 factorial design. The 33 factorial design was used for studying the effect of the main preparation variables on particle size and percent drug entrapment efficiency of the nanoparticles. A modified nanoprecipitation method was used to prepare nanoparticles successfully by using the biodegradable polymer poly(lactic-co-glycolic)acid (PLGA), and they were characterized for various parameters such as particle size, shape, zeta potential, percent drug entrapment efficiency, percent process yield and in vitro drug release behavior. Examination of the interaction between the excipients used as well as investigation of the nature of the drug, the formulation and the nature of the drug in the formulations was carried out by FTIR studies. Different kinetic models were used to analyze the in vitro drug release data. The preferred formulation showed a particle size of 127.6 ± 1.9 nm, PDI of 0.239 ± 0.013, zeta potential of -29.2 mV, entrapment efficiency of 72.46 ± 3.8% and process yield of 89.65 ± 1.3%. TEM results showed that these nanoparticles were spherical in shape and follow the Korsmeyer-Peppas model with different release exponent values.

  4. Characterization of rheology and release profiles of olanzapine-loaded lipid-core nanocapsules in thermosensitive hydrogel.

    Science.gov (United States)

    Dimer, F A; Pohlmann, A R; Guterres, S S

    2013-12-01

    In this study we developed a new drug delivery system for olanzanpine comprised of drug-loaded lipid-core nanocapsules incorporated in a thermosensitive hydrogel, intended to sustain the drug release. Firstly, olanzapine, a hydrophobic drug, was loaded in poly(epsilon-caprolactone) lipid core nanocapsules prepared by interfacial deposition of preformed polymer. The effects of the presence of ethanol and the amounts of sorbitan monostearate and medium-chain triglycerides on the particle size, zeta potential, polydispersity index, presence of microparticles and encapsulation efficiency were investigated using a 2(3) factorial design. The optimized nanocapsules were incorporated into a hydrophilic polymer (Poloxamer 407) dispersion in order to obtain a thermosensitive gel. The formulation containing 0.077 g of sorbitan monostearate, 0.22 ml of medium-chain triglycerides, 3 ml of ethanol and 18% of the thermosensitive polymer was selected according to the physicochemical properties. The rheology and release profiles of the mixed hydrophobic and hydrophilic delivery system were successfully characterized and revealed its great potential for the administration of hydrophobic drugs such as olanzapine with sustained in situ drug release.

  5. Ascorbyl Tetraisopalmitate Inclusion into Υ-Cyclodextrin and Mesoporous SBA-15: Preparation, Characterization and In Vitro Release Study

    Directory of Open Access Journals (Sweden)

    Maria Bastianini

    2017-07-01

    Full Text Available Ascorbic acid or vitamin C is a strong antioxidant widely used in cosmetic and food fields. This vitamin is very unstable and rapidly undergoes degradation. In order to solve this problem and to obtain a stable ascorbic acid, Nikkol Group has developed ascorbyltetraisopalmitate (VC-IP. This raw material is an oil phase, already well-known and employed in the cosmetic market. The objective of this study is to obtain VC-IP in micro-powder form, in order to produce a new raw material that is easily dispersible in oil and water phases and useful for make-up and color cosmetic applications. Various types of drug carriers were studied and considered in order to support VC-IP and obtain the conversion in powder. Υ-cyclodextrin and mesoporous silica SBA-15 were chosen as the best candidates. A white powder of supported VC-IP was obtained with each carrier (VC-IP@cyclodextrin, VC-IP@SBA-15. The systems underwent physicochemical characterization and in vitro release tests were carried out. Based on the conducted study, it can be concluded that by supporting VC-IP on Υ-cyclodextrin and SBA-15, it is feasible to obtain a new raw material in powder form. The two carriers possess different release profiles, adding the possibility to finely tune the release of the active component in smart formulations.

  6. Characterization of aerosol pollution events in France using ground-based and POLDER-2 satellite data

    Directory of Open Access Journals (Sweden)

    M. Kacenelenbogen

    2006-01-01

    Full Text Available We analyze the relationship between daily fine particle mass concentration (PM2.5 and columnar aerosol optical thickness derived from the Polarization and Directionality of Earth's Reflectances (POLDER satellite sensor. The study is focused over France during the POLDER-2 lifetime between April and October 2003. We have first compared the POLDER derived aerosol optical thickness (AOT with integrated volume size distribution derived from ground-based Sun Photometer observations. The good correlation (R=0.72 with sub-micron volume fraction indicates that POLDER derived AOT is sensitive to the fine aerosol mass concentration. Considering 1974 match-up data points over 28 fine particle monitoring sites, the POLDER-2 derived AOT is fairly well correlated with collocated PM2.5 measurements, with a correlation coefficient of 0.55. The correlation coefficient reaches a maximum of 0.80 for particular sites. We have analyzed the probability to find an appropriate air quality category (AQC as defined by U.S. Environmental Protection Agency (EPA from POLDER-2 AOT measurements. The probability can be up to 88.8% (±3.7% for the "Good" AQC and 89.1% (±3.6% for the "Moderate" AQC.

  7. On-ground characterization of the Euclid's CCD273-based readout chain

    Science.gov (United States)

    Szafraniec, Magdalena; Azzollini, R.; Cropper, M.; Pottinger, S.; Khalil, A.; Hailey, M.; Hu, D.; Plana, C.; Cutts, A.; Hunt, T.; Kohley, R.; Walton, D.; Theobald, C.; Sharples, R.; Schmoll, J.; Ferrando, P.

    2016-07-01

    Euclid is a medium class European Space Agency mission scheduled for launch in 2020. The goal of the survey is to examine the nature of Dark Matter and Dark Energy in the Universe. One of the cosmological probes used to analyze Euclid's data, the weak lensing technique, measures the distortions of galaxy shapes and this requires very accurate knowledge of the system point spread function (PSF). Therefore, to ensure that the galaxy shape is not affected, the detector chain of the telescope's VISible Instrument (VIS) needs to meet specific performance performance requirements. Each of the 12 VIS readout chains consisting of 3 CCDs, readout electronics (ROE) and a power supply unit (RPSU) will undergo a rigorous on-ground testing to ensure that these requirements are met. This paper reports on the current status of the warm and cold testing of the VIS Engineering Model readout chain. Additionally, an early insight to the commissioning of the Flight Model calibration facility and program is provided.

  8. On Advanced Estimation Techniques for Exoplanet Detection and Characterization using Ground-Based Coronagraphs

    Science.gov (United States)

    Lawson, Peter R.; Frazin, Richard; Barrett, Harrison; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; Gladysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jerome; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Perrin, Marshall; Poyneer, Lisa; Pueyo, Laurent; Savransky, Dmitry; Soummer, Remi

    2012-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We provide a formal comparison of techniques through a blind data challenge and evaluate performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012.

  9. Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA field experiment

    Directory of Open Access Journals (Sweden)

    J. Brito

    2014-11-01

    Full Text Available This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of biomass burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional biomass burning pollution (average CO mixing ratio of 0.6 ppm, occasionally superimposed by intense (up to 2 ppm of CO, freshly emitted biomass burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during biomass burning (BB events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe, among the highest values described in the literature. We examined the ageing of biomass burning organic aerosol (BBOA using the changes in the H : C and O : C ratios, and found that throughout most of the

  10. Expression profiling and structural characterization of microRNAs in adipose tissues of hibernating ground squirrels.

    Science.gov (United States)

    Wu, Cheng-Wei; Biggar, Kyle K; Storey, Kenneth B

    2014-12-01

    MicroRNAs (miRNAs) are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 miRNAs in brown (BAT) and white adipose tissue (WAT) during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six miRNAs including let-7a, let-7b, miR-107, miR-150, miR-222 and miR-31 was significantly downregulated in WAT (Pstructure-influenced changes in pre-miRNA processing efficiency in the squirrel. As well, the expression of miRNA processing enzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of miRNA expression in adipose tissues may be linked to distinct biological roles in WAT and BAT during hibernation and may involve the regulation of signaling cascades.

  11. Preparation, characterization, and in vitro release of gentamicin from coralline hydroxyapatite-alginate composite microspheres.

    Science.gov (United States)

    Sivakumar, M; Rao, K Panduranga

    2003-05-01

    In this work, composite microspheres were prepared from bioactive ceramics such as coralline hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] granules, a biodegradable polymer, sodium alginate, and an antibiotic, gentamicin. Previously, we have shown a gentamicin release from coralline hydroxyapatite granules-chitosan composite microspheres. In the present investigation, we attempted to prepare composite microspheres containing coralline hydroxyapatite granules and sodium alginate by the dispersion polymerization technique with gentamicin incorporated by absorption method. The crystal structure of the composite microspheres was analyzed using X-ray powder diffractometer. Fourier transform infrared spectra clearly indicated the presence of per-acid of sodium alginate, phosphate, and hydroxyl groups in the composite microspheres. Scanning electron micrographs and optical micrographs showed that the composite microspheres were spherical in shape and porous in nature. The particle size of composite microspheres was analyzed, and the average size was found to be 15 microns. The thermal behavior of composite microspheres was studied using thermogravimetric analysis and differential scanning calorimetric analysis. The cumulative in vitro release profile of gentamicin from composite microspheres showed near zero order patterns.

  12. Effects of formulation variables and characterization of guaifenesin wax microspheres for controlled release.

    Science.gov (United States)

    Mani, Narasimhan; Park, M O; Jun, H W

    2005-01-01

    Sustained-release wax microspheres of guaifenesin, a highly water-soluble drug, were prepared by the hydrophobic congealable disperse method using a salting-out procedure. The effects of formulation variables on the loading efficiency, particle properties, and in-vitro drug release from the microspheres were determined. The type of dispersant, the amount of wetting agent, and initial stirring time used affected the loading efficiency, while the volume of external phase and emulsification speed affected the particle size of the microspheres to a greater extent. The crystal properties of the drug in the wax matrix and the morphology of the microspheres were studied by differential scanning calorimetry (DSC), powder x-ray diffraction (XRD), and scanning electron microscopy (SEM). The DSC thermograms of the microspheres showed that the drug lost its crystallinity during the microencapsulation process, which was further confirmed by the XRD data. The electron micrographs of the drug-loaded microspheres showed well-formed spherical particles with a rough exterior.

  13. Cross-Characterization of Aerosol Properties from Multiple Spaceborne Sensors Facilitated by Regional Ground-Based Observations

    Science.gov (United States)

    Petrenko, Maksym; Ichoku, Charles; Leptoukh, Gregory

    2010-01-01

    Aerosol observations from space have become a standard source for retrieval of aerosol properties on both regional and global scales. Indeed, the large number of currently operational spaceborne sensors provides for unprecedented access to the most complete set of complimentary aerosol measurements ever to be available. Nonetheless, this resource remains under-utilized, largely due to the discrepancies and differences existing between the sensors and their aerosol products. To characterize the inconsistencies and bridge the gap that exists between the sensors, we have designed and implemented an online Multi-sensor Aerosol Products Sampling System (MAPSS) that facilitates the joint sampling of aerosol data from multiple sensors. MAPSS consistently samples aerosol products from multiple spaceborne sensors using a unified spatial and temporal resolution, where each dataset is sampled over Aerosol Robotic Network (AERONET) locations together with coincident AERONET data samples. In this way, MAPSS enables a direct cross-characterization and data integration between aerosol products from multiple sensors. Moreover, the well-characterized co-located ground-based AERONET data provides the basis for the integrated validation of these products.

  14. Preparation and characterization of TAM-loaded HPMC/PAN composite fibers for improving drug-release profiles.

    Science.gov (United States)

    Shen, Xiaxia; Yu, Dengguang; Zhang, Xiaofei; Branford-White, Christopher; Zhu, Limin

    2011-01-01

    The present paper reports the preparation and characterization of composite hydroxypropyl methylcellulose/polyacrylonitrile (HPMC/PAN)-medicated fibers via a wet spinning technique. Tamoxifen (TAM) was selected as a model drug. Numerous analyses were conducted to characterize the mechanical, structure and morphology properties of the composite fibers. The drug content and in vitro dissolution behavior were also investigated. SEM images showed that the TAM-loaded HPMC/PAN composite fibers had a finger-like outer skin and a porous structure. FT-IR spectra demonstrated that there was a good compatibility between polymer and drug. Results from X-ray diffraction and DSC suggested that most of the incorporated TAM was evenly distributed in the fiber matrix in an amorphous state, except for a minority that aggregated on the surface of fibers. The drug content in the fibers was lower than that in the spinning solution and about 10% of TAM was lost during spinning process. In vitro dissolution results indicated that, compared to TAM-PAN fibers, HPMC/PAN composite systems had weaker initial burst release effects and more drug-loading. The combination of hydrophilic polymer HPMC with PAN could improve the performance of polymer matrix composite fibers in regulating the drug-release profiles.

  15. Interaction between DNA and Drugs Having Protonable Basic Groups: Characterization through Affinity Constants, Drug Release Kinetics, and Conformational Changes.

    Science.gov (United States)

    Alarcón, Liliana P; Baena, Yolima; Manzo, Rubén H

    2017-01-04

    This paper reports the in vitro characterization of the interaction between the phosphate groups of DNA and the protonated species of drugs with basic groups through the determination of the affinity constants, the reversibility of the interaction, and the effect on the secondary structure of the macromolecule. Affinity constants of the counterionic condensation DNA-drug were in the order of 10⁶. The negative electrokinetic potential of DNA decreased with the increase of the proportion of loading drugs. The drugs were slowly released from the DNA-drug complexes and had release kinetics consistent with the high degree of counterionic condensation. The circular dichroism profile of DNA was not modified by complexation with atenolol, lidocaine, or timolol, but was significantly altered by the more lipophilic drugs benzydamine and propranolol, revealing modifications in the secondary structure of the DNA. The in vitro characterization of such interactions provides a physicochemical basis that would contribute to identify the effects of this kind of drugs in cellular cultures, as well as side effects observed under their clinical use. Moreover, this methodology could also be projected to the fields of intracellular DNA transfection and the use of DNA as a carrier of active drugs.

  16. Interaction between DNA and Drugs Having Protonable Basic Groups: Characterization through Affinity Constants, Drug Release Kinetics, and Conformational Changes

    Directory of Open Access Journals (Sweden)

    Liliana P. Alarcón

    2017-01-01

    Full Text Available This paper reports the in vitro characterization of the interaction between the phosphate groups of DNA and the protonated species of drugs with basic groups through the determination of the affinity constants, the reversibility of the interaction, and the effect on the secondary structure of the macromolecule. Affinity constants of the counterionic condensation DNA–drug were in the order of 106. The negative electrokinetic potential of DNA decreased with the increase of the proportion of loading drugs. The drugs were slowly released from the DNA–drug complexes and had release kinetics consistent with the high degree of counterionic condensation. The circular dichroism profile of DNA was not modified by complexation with atenolol, lidocaine, or timolol, but was significantly altered by the more lipophilic drugs benzydamine and propranolol, revealing modifications in the secondary structure of the DNA. The in vitro characterization of such interactions provides a physicochemical basis that would contribute to identify the effects of this kind of drugs in cellular cultures, as well as side effects observed under their clinical use. Moreover, this methodology could also be projected to the fields of intracellular DNA transfection and the use of DNA as a carrier of active drugs.

  17. Subtropical and Polar Cirrus Clouds Characterized by Ground-Based Lidars and CALIPSO/CALIOP Observations

    Directory of Open Access Journals (Sweden)

    Córdoba-Jabonero Carmen

    2016-01-01

    Full Text Available Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in two stations: the Metropolitan city of Sao Paulo (MSP, Brazil, 23.3°S 46.4°W, located at subtropical latitudes, and the Belgrano II base (BEL, Argentina, 78ºS 35ºW in the Antarctic continent. Optical (COD-cloud optical depth and LR-Lidar Ratio and macrophysical (top/base heights and thickness properties of both the subtropical and polar cirrus clouds are reported. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In general, Cirrus clouds are detected at similar altitudes by CALIOP. However, a poor agreement is achieved in the LR retrieved between ground-based lidars and space-borne CALIOP measurements, likely due to the use of a fixed (or low-variable LR value in CALIOP inversion procedures.

  18. Characterizing peat palm forest degradation in the Peruvian Amazon from space and on the ground

    Science.gov (United States)

    Hergoualc'h, Kristell; Gutierrez-Velez, Victor Hugo; van Lent, Jeffrey; Verchot, Louis Vincent

    2016-04-01

    Peru has the second largest area of peatlands in the Tropics however little is known on how the biogeochemical cycle of its peat forests can be affected through anthropogenic intervention. The most representative land cover on peat is a Mauritia flexuosa-dominated palm swamp forest which has been under human pressure over decades due the high demand for the M. flexuosa fruit often collected by cutting down the entire palm. Degradation of these carbon-dense forests can severely affect emissions of greenhouse gases and contribute to climate change. The objectives of this research were to assess the impacts on soil trace gas fluxes and biomass carbon stocks of peat palm swamp forest degradation and to explore the potential of remote sensing methods combined with field measurements to map the distribution of peat palm swamp forest according degradation levels. Results suggest a shift in forest composition from palm- to woody-tree dominated forest following degradation. We also found that human intervention in peat palm swamp forest can translate into substantial reductions in tree carbon stocks with a decrease in initial biomass (above and below-ground) stocks (118.3 ± 1.1 Mg C ha-1) by 26 and 44% following medium and high degradation. Preliminary results suggest high and low soil CH4 and CO2 emission rates on average, as compared to Southeast Asian peat swamp forests whereas N2O emissions are of the same magnitude. Degradation seems to disrupt soil respiration mainly through micro-climatic changes induced by reduced canopy cover. The analysis indicates a good potential to discriminate areas of peat palm swamp forest with different levels of degradation from other land covers, suggesting the feasibility of monitoring peat palm swamp forest degradation using remote sensing analyses.

  19. Subtropical and Polar Cirrus Clouds Characterized by Ground-Based Lidars and CALIPSO/CALIOP Observations

    Science.gov (United States)

    Córdoba-Jabonero, Carmen; Lopes, Fabio J. S.; Landulfo, Eduardo; Ochoa, Héctor; Gil-Ojeda, Manuel

    2016-06-01

    Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in two stations: the Metropolitan city of Sao Paulo (MSP, Brazil, 23.3°S 46.4°W), located at subtropical latitudes, and the Belgrano II base (BEL, Argentina, 78ºS 35ºW) in the Antarctic continent. Optical (COD-cloud optical depth and LR-Lidar Ratio) and macrophysical (top/base heights and thickness) properties of both the subtropical and polar cirrus clouds are reported. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In general, Cirrus clouds are detected at similar altitudes by CALIOP. However, a poor agreement is achieved in the LR retrieved between ground-based lidars and space-borne CALIOP measurements, likely due to the use of a fixed (or low-variable) LR value in CALIOP inversion procedures.

  20. Characterization of the Hanford 300 area burial grounds. Task IV. Biological transport

    Energy Technology Data Exchange (ETDEWEB)

    Fitzner, R.E.; Gano, K.A.; Rickard, W.H.; Rogers, L.E.

    1979-10-01

    The characteristics of radioactive waste burial sites at the 300 area burial grounds on the Department of Energy's Hanford Site, southeastern Washington were studied. The potential vectors of radionuclide transport studied were vegetation and animals. The overall results showed a low potential for uptake and transport of radionuclides from the 300 area sites. However, additional methods to control physical and biological mechanisms may contribute to the effectiveness of waste burial practices. From the results, the Biological Transport task recommended field studies which include reduction of soil erosion and addition of biobarriers to plants and animals. Vegetation plays a major role in reducing soil erosion, and thereby maintaining the backfill over the burial sites. Of the several species found on the 300 area sites, cheatgrass (Bromus tectorum) appears to be the most desirable as a cover. Besides retarding erosion, it has a shallow root system (does not easily penetrate buried material); it has a low affinity for radionuclide uptake; and its tissues are not easily blown away. Small mammals (specifically, mice) appear to have the most potential for radionuclide exposure and uptake. Small mammals were live-trapped within 10 x 10-meter trap grids. Each animal trapped was surgically implanted with a thermoluminescent dosimeter. When the animal was recaptured, the dosimeter was removed and read for exposure. Exposures were reported in milli-Roentgens. The most consistently trapped small mammals were the Great Basin pocket mouse (Perognathus parvus) and the deer mouse (Peromyscus maniculatus). Results from the dosimeter readings showed that some of those animals had higher than background exposures. Biobarriers to animals could be considered as a mechanism to reduce the potential for radionuclide transport.

  1. Preparation and Characterization of Starch Nanoparticles for Controlled Release of Curcumin

    Directory of Open Access Journals (Sweden)

    Suk Fun Chin

    2014-01-01

    Full Text Available Curcumin was loaded onto starch nanoparticles by using in situ nanoprecipitation method and water-in-oil microemulsion system. Curcumin loaded starch nanoparticles exhibited enhanced solubility in aqueous solution as compared to free curcumin. Effects of formulation parameters such as types of reaction medium, types of surfactant, surfactant concentrations, oil/ethanol ratios, loading time, and initial curcumin concentration were found to affect the particle size and loading efficiency (LF of the curcumin loaded starch nanoparticles. Under optimum conditions, curcumin loaded starch nanoparticles with mean particles size of 87 nm and maximum loading efficiency of 78% were achieved. Curcumin was observed to release out from starch nanoparticles in a sustained way under physiological pH over a period of 10 days.

  2. A characterization of DNA release in Pseudomonas aeruginosa cultures and biofilms

    DEFF Research Database (Denmark)

    Allesen-Holm, Marie; Barken, Kim Bundvig; Yang, Liang;

    2006-01-01

    to whole-genome DNA. Evidence that the extracellular DNA in P. aeruginosa biofilms and cultures is generated via lysis of a subpopulation of the bacteria was obtained through experiments where extracellular beta-galactosidase released from lacZ-containing P. aeruginosa strains was assessed. Experiments......Pseudomonas aeruginosa produces extracellular DNA which functions as a cell-to-cell interconnecting matrix component in biofilms. Comparison of extracellular DNA and chromosomal DNA by the use of polymerase chain reaction and Southern analysis suggested that the extracellular DNA is similar...... with the wild type and lasIrhlI, pqsA, pqsL and fliMpilA mutants indicated that the extracellular DNA is generated via a mechanism which is dependent on acyl homoserine lactone and Pseudomonas quinolone signalling, as well as on flagella and type IV pili. Microscopic investigation of flow chamber-grown wild...

  3. Enzymatic Release and Characterization of Novel Bioactive Peptides from Milk Proteins

    DEFF Research Database (Denmark)

    De Gobba, Cristian

    Milk is considered the most complete food, providing most of the nutrients needed. Milk proteins are not only important for their function as a source of amino acids, but they are also a source of bioactive peptides. These are short amino acid sequences with different activities that have......-inhibitory, antioxidant and antimicrobial peptides) released from milk proteins by mean of enzyme-catalysed hydrolysis. Goat milk fractions (produced using microfiltration membranes) and bovine casein were used as substrates. The goat milk fractions (retentate, permeate and skimmed milk) were hydrolysed with two...... protein hydrolysates made in other studies. Regarding radical scavenging activity, the bovine casein hydrolysates also showed a positive correlation between extent of hydrolysis and activity, although the difference between the unhydrolysed sample and the hydrolysates was less marked. The goat milk...

  4. Preparation and characterization of ketoprofen loaded eudragit RS polymeric nanoparticles for controlled release

    Science.gov (United States)

    Anh, Nguyen Tuan; Chi, Nguyen T.; Khai Tran, T.; Tuyen Dao, T. P.; Nhan Le, N. T.; Mau Chien, Dang; Hoai, Nguyen To

    2012-12-01

    Nanospheres containing ketoprofen (Keto) and polymer eudragit RS were prepared using an emulsion solvent evaporation method. The ultrasonic probe (VCX500, vibracell) was used as a tool to disperse oil phase into aqueous phase leading to water/oil emulsion. Nanoparticles were successfully prepared and their morphologies and diameters were confirmed by transmission electron microscope (TEM) and dynamic light scattering (DLS), respectively. The result showed that particles were spherical with submicron size. The particle size was dependent on the RS concentration, emulsification tools and the types of organic solvents. For the encapsulation ability, Keto-loaded RS nanoparticle showed 9.8% of Keto in nanoparticle, which was evaluated by high-performance liquid chromatography (HPLC). Moreover, the drug release behavior of Keto-loaded eudragit RS nanoparticle was also investigated in vitro at pH 7.4 and compared to referential profenid.

  5. Enzymatic Release and Characterization of Novel Bioactive Peptides from Milk Proteins

    DEFF Research Database (Denmark)

    De Gobba, Cristian

    -inhibitory, antioxidant and antimicrobial peptides) released from milk proteins by mean of enzyme-catalysed hydrolysis. Goat milk fractions (produced using microfiltration membranes) and bovine casein were used as substrates. The goat milk fractions (retentate, permeate and skimmed milk) were hydrolysed with two...... protein hydrolysates made in other studies. Regarding radical scavenging activity, the bovine casein hydrolysates also showed a positive correlation between extent of hydrolysis and activity, although the difference between the unhydrolysed sample and the hydrolysates was less marked. The goat milk...... hydrolysates, instead, showed a difference between the fractions more than the degree of hydrolysis, the retentate being the most active radical scavenger regardless the degree of hydrolysis and enzyme used. Both hydrolysates are among the most active radical scavenging milk protein hydrolysates known...

  6. Expression and Characterization of a Thermostable Acyl-peptide Releasing Enzyme ST0779 from Sulfolobus tokodaii

    Institute of Scientific and Technical Information of China (English)

    LI Rong; ZHANG Fei; CAO Shu-gui; XIE Gui-qiu; GAO Ren-jun

    2012-01-01

    Acyl-peptide releasing enzyme(AARE) belongs to a serine peptidase family and catalyzes the NH2-terminal hydrolysis of Nα-acylpeptides to release Nα-acylated amino acids.ORF0779(ORF=open reading frame)from thermophilic archaea Sulfolobus tokodaii(ST0779) was cloned and expressed in E.coti BL21 and the expressed protein was identified as a thermostable AARE.The target protein could be optimally overexpressed in E.coli at 30 ℃ for 8 h with 0.1 mmol/L isopropyl β-dthiogalactoside(IPTG).The crude enzyme was heated at 70 ℃ for 30 min,and then the target protein could account for above 40% of the total protein.The purification fold was 27 and the enzyme showed both esterase activity and peptidase activity.The optimal temperature and pH for ST0779 were 70 ℃and 8.0 when Ac-Ala3 was used as substrate.The half-life of the enzyme(0.2 mg/mL) at 90 ℃ was about 16 h,indicating that the enzyme exhibits a favorable thermostability.The activity of ST0779 could still remain over 85% after being treated at 25 ℃ in different buffers with pH range from 6.0 to10.0 for 24 h,which indicates ST0779 is stable in neutral or slight alkali environment.Under neutral or slightly alkali conditions,the enzyme exhibits really high catalytic efficiency against acyl-peptide,and the optimal substrate is Ac-Ala3.Most metal ions have no inhibition effect on the activity of ST0779,while 4% activity of ST0779 is inhibited in the presence of K+.This enzyme was supposed to be applied in the analysis of protein sequencing and the synthesis of small peptides.

  7. Expression Profiling and Structural Characterization of MicroRNAs in Adipose Tissues of Hibernating Ground Squirrels

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Wu

    2014-12-01

    Full Text Available MicroRNAs (miRNAs are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 miRNAs in brown (BAT and white adipose tissue (WAT during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six miRNAs including let-7a, let-7b, miR-107, miR-150, miR-222 and miR-31 was significantly downregulated in WAT (P < 0.05, which was 16%–54% of euthermic non-torpid control squirrels, whereas expression of three miRNAs including miR-143, miR-200a and miR-519d was found to be upregulated by 1.32–2.34-fold. Similarly, expression of more miRNAs was downregulated in BAT during torpor. We detected reduced expression of 6 miRNAs including miR-103a, miR-107, miR-125b, miR-21, miR-221 and miR-31 (48%–70% of control, while only expression of miR-138 was significantly upregulated (2.91 ± 0.8-fold of the control, P < 0.05. Interestingly, miRNAs found to be downregulated in WAT during torpor were similar to those dysregulated in obese humans for increased adipogenesis, whereas miRNAs with altered expression in BAT during torpor were linked to mitochondrial β-oxidation. miRPath target prediction analysis showed that miRNAs downregulated in both WAT and BAT were associated with the regulation of mitogen-activated protein kinase (MAPK signaling, while the miRNAs upregulated in WAT were linked to transforming growth factor β (TGFβ signaling. Compared to mouse sequences, no unique nucleotide substitutions within the stem-loop region were discovered for the associated pre-miRNAs for the miRNAs used in this study, suggesting no structure-influenced changes in pre-miRNA processing efficiency in the squirrel. As well, the expression of miRNA processing enzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of miRNA expression in adipose tissues may

  8. Expression Profiling and Structural Characterization of MicroRNAs in Adipose Tissues of Hibernating Ground Squirrels

    Institute of Scientific and Technical Information of China (English)

    Cheng-Wei Wu; Kyle K. Biggar; Kenneth B. Storey

    2014-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 miRNAs in brown (BAT) and white adipose tissue (WAT) during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six miRNAs including let-7a, let-7b, miR-107, miR-150, miR-222 and miR-31 was significantly downregulated in WAT (P < 0.05), which was 16%–54% of euthermic non-torpid control squirrels, whereas expression of three miRNAs including miR-143, miR-200a and miR-519d was found to be upregulated by 1.32–2.34-fold. Similarly, expression of more miRNAs was downregulated in BAT during torpor. We detected reduced expression of 6 miRNAs including miR-103a, miR- 107, miR-125b, miR-21, miR-221 and miR-31 (48%–70% of control), while only expression of miR-138 was significantly upregulated (2.91 ± 0.8-fold of the control, P <0.05). Interestingly, miRNAs found to be downregulated in WAT during torpor were similar to those dysregulated in obese humans for increased adipogenesis, whereas miRNAs with altered expression in BAT during torpor were linked to mitochondrial b-oxidation. miRPath target prediction analysis showed that miRNAs downregulated in both WAT and BAT were associated with the regulation of mitogen- activated protein kinase (MAPK) signaling, while the miRNAs upregulated in WAT were linked to transforming growth factor b (TGFb) signaling. Compared to mouse sequences, no unique nucleotide substitutions within the stem-loop region were discovered for the associated pre-miRNAs for the miRNAs used in this study, suggesting no structure-influenced changes in pre-miRNA processing efficiency in the squirrel. As well, the expression of miRNA processing enzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of miRNA expression in adipose tissues may be linked to

  9. Synthesis, characterization, stability evaluation and release kinetics of fiber-encapsulated carotene nano-capsules

    Directory of Open Access Journals (Sweden)

    Sen Gupta, S.

    2015-12-01

    Full Text Available In the present work, carotenoids were isolated (1.2% from crude palm oil and encapsulated with isabgol fiber (Psyllium husk. The efficiency of encapsulation was 82.23±1.42%. The morphology of the capsules showed rough surface texture with minimal pores. The amorphous natures of the nano-capsules was obvious from X-ray diffraction patterns. DSC studies showed high thermal stability of the nano-capsules between 20–120 °C. In vitro release studies revealed that controlled release from the nano-capsules could be achieved using isabgol fiber as encapsulant. However it was observed that the nano-capsules followed a non-Fickian diffusion pattern. Good DPPH-radical scavenging and metal-chelation activities were observed for encapsulated carotenoids. Shelf-life studies showed that the nano-capsules gradually degraded at 97% relative humidity, as the moisture-induced rancidity was evidently not extensive.En el presente trabajo los carotenos fueron aislados (1,2% a partir de aceite de palma crudo y encapsulados con fibra de isabgol (cáscara de psyllium. La eficiencia de encapsulación fue 82,23±1,42 %. La morfología de las cápsulas mostró una textura áspera de la superficie con mínimos poros. La naturaleza amorfa de las nanocápsulas fue evidenciada a partir de patrones de difracción de rayos X. Los estudios de DSC mostraron una alta estabilidad térmica de las nanocápsulas entre 20–120 °C. En los estudios de liberación in vitro se vió que la liberación controlada de las nanocápsulas se podría lograr mediante fibra isabgol como encapsulante. Sin embargo se observó que las nanocápsulas siguieron un patrón de difusión no- Fickian. Se observaron buenas actividades DPPH captadoras de radicales y actividades de quelación de metal para carotenoides encapsulados. Los estudios sobre la vida útil mostraron que las nanocápsulas se degradan gradualmente con una humedad relativa del 97%, y aunque la humedad indujo el enranciamiento, este

  10. Quantification and characterization of colloids and organic carbon released under oscillating redox conditions

    Science.gov (United States)

    Jin, Yan; Afsar, Mohammad; Yan, Jing

    2017-04-01

    Wetlands account for 8-10% of the world's land surface but their soils contain 20-30% of globe terrestrial carbon. The carbon is intimately mixed with minerals in the soils. Thus, mineral-associated-organic carbon (MOC), which often exists as colloids, can directly affect global carbon cycling at multiple scales. When wetland soils become reduced, large quantities of MOC are released due to dissolution of metal oxides, and mobilized and discharged into adjacent streams during rainfall events. Despite the clear relevance of wetlands to global carbon reservoirs and cycling, MOC, as an important component of wetland carbon pool, is poorly understood. Further, understanding of the key factors controlling the fluxes and compositional characteristics of MOC thus the underlying reaction mechanisms that are responsible for the sequestration and stabilization of OC is also lacking. Here we present results from both field sampling and laboratory experiments on the amount, size distribution, and composition of MOC as influenced by oscillating redox conditions. Using both conventional and advanced analytical techniques, including x-ray photoelectron spectroscopy (XPS) and isotope ratio mass spectroscopy (IRMS), we identify 4 MOC size fractions: 450-1000 nm, 100-450 nm, 2.3-100 nm and < 2.3 nm. Normalized atomic% of different elements obtained from XPS analysis reveal clear variations in mineral and OC compositions in the different size fractions. In particular, the "nano sized" MOC (i.e., 2.3-100 nm fraction) has the highest Mg/Al ratio and OC/mineral ratio, the lowest percentages of Al and Si, is mostly depleted in C-C/C-H functional groups but enriched with C=0 and C-O/C-N groups in contract to other size groups. IRMS analysis shows depletion of the heavier isotope 13C from the 2.3-100 nm fraction indicating the presence of more lignin derivatives in this size fraction. The observed size-dependent heterogeneity on C attachment and release to/from MOC can lead to more

  11. Release profiles and morphological characterization by atomic force microscopy and photon correlation spectroscopy of 99mTechnetium-fluconazole nanocapsules.

    Science.gov (United States)

    de Assis, Danielle Nogueira; Mosqueira, Vanessa Carla Furtado; Vilela, José Mário Carneiro; Andrade, Margareth Spangler; Cardoso, Valbert Nascimento

    2008-02-12

    Several classes of antifungal have been employed in candidiasis treatment, but patients with advanced immunodeficiency can present unsatisfactory results after therapy. In these cases, high doses of drugs or the use of multiple agents are sometimes used, and hence increasing the risk of serious side effects. Considering theses difficulties, the encapsulation of antifungal agents in nanoparticulate carriers has been used with the objective of modifying the pharmacokinetic of drugs resulting in more efficient treatments with less side effects. The purpose of this work was the preparation, characterization and the investigation of the release profiles of radiolabeled fluconazole nanocapsules. The size, homogeneity and zeta potential of NC preparations were determined with a Zetasizer 3000HS. The morphology and the structural organization were evaluated by atomic force microscopy (AFM). The release study in vitro of NC was evaluated in physiologic solution with or without 70% mouse plasma. The labeling yield of fluconazole with 99mTc was 94% and the radiolabeled drug was stable within 24h period. The encapsulation percentage of 99mTc-fluconazole in PLA-POLOX NC and PLA-PEG NC was approximately of 30%. The average diameter calculated by photon correlation spectroscopy (PCS) varied from 236 to 356 nm, while the average diameter determined by AFM varied from 238 to 411 nm. The diameter/height relation decreased significantly when 25% glutaraldehyde was used for NC fixation on mica. The zeta potential varied from -55 to -69 nm and surface-modified NC showed lower absolute values than conventional NC. The in vitro release of 99mTc-fluconazole in plasma medium of the conventional and surface-modified NC was greater than in saline. The drug release in plasma medium from conventional NC was faster than for surface-modified NC. The results obtained in this work suggest that the nanocapsules containing fluconazole could be used to identify infectious foci, due to the properties

  12. Ketorolac trometamol topical formulations: release behaviour, physical characterization, skin permeation, efficacy and gastric safety.

    Science.gov (United States)

    El-Setouhy, Doaa Ahmed; El-Ashmony, Sahar Mohy Ahmed

    2010-01-01

    The objective of this study was to improve systemic delivery of the highly analgesic ketorolac trometamol (ketorolac tromethamine) via the transdermal route, through cost-effective topical formulations, to avoid most of the problems associated with ketorolac trometamol therapy. In-vitro release behaviour of the drug from different microemulsion and emulgel formulations was evaluated. E2 emulgel (based on isopropyl myristate as penetration enhancer) and E7 emulgel (based on Brij 92 as penetration enhancer) were evaluated for their physical properties, rat skin permeation, in-vivo analgesic effect (hot-plate test and the paw pressure test), acute and chronic anti-inflammatory activity and gastric safety. Isopropyl myristate and the synergistic effect of the two known penetration enhancers (propylene glycol and Brij 92) significantly modulated drug permeation and may be a promising approach for the transdermal delivery of ketorolac trometamol and other drugs. Selected in-vivo tested formulae (E2 and E7) caused significantly less ulcer score and less gastric erosion compared with oral ketorolac trometamol. E7 showed significantly higher analgesic and anti-inflammatory activity compared with E2 with no significant difference compared with oral ketorolac trometamol. The developed ketorolac trometamol E7 emulgel appeared promising for dermal and transdermal delivery of ketorolac trometamol, which would circumvent most of the problems associated with drug therapy.

  13. Lactose autoinduction with enzymatic glucose release: characterization of the cultivation system in bioreactor.

    Science.gov (United States)

    Mayer, Sonja; Junne, Stefan; Ukkonen, Kaisa; Glazyrina, Julia; Glauche, Florian; Neubauer, Peter; Vasala, Antti

    2014-02-01

    The lactose autoinduction system for recombinant protein production was combined with enzymatic glucose release as a method to provide a constant feed of glucose instead of using glycerol as a carbon substrate. Bioreactor cultivation confirmed that the slow glucose feed does not prevent the induction by lactose. HPLC studies showed that with successful recombinant protein production only a very low amount of lactose was metabolized during glucose-limited fed-batch conditions by the Escherichia coli strain BL21(DE3)pLysS in well-aerated conditions, which are problematic for glycerol-based autoinduction systems. We propose that slow enzymatic glucose feed does not cause a full activation of the lactose operon. However recombinant PDI-A protein (A-domain of human disulfide isomerase) was steadily produced until the end of the cultivation. The results of the cultivations confirmed our earlier observations with shaken cultures showing that lactose autoinduction cultures based on enzymatic glucose feed have good scalability, and that this system can be applied also to bioreactor cultivations.

  14. Characterizing the Variability of Stars with Early-Release Kepler Data

    CERN Document Server

    Ciardi, David R; Bryden, Geoff; van Eyken, Julian; Howell, Steve B; Kane, Stephen R; Plavchan, Peter; Stauffer, John R

    2010-01-01

    We present a variability analysis of the first quarter of data publicly released by the Kepler project. Using the stellar parameters from the Kepler Input Catalog, we have separated the sample in 129,000 dwarfs and 17,000 giants, and further sub-divided, the luminosity classes into temperature bins corresponding approximately to the spectral classes A, F, G, K, and M. G-dwarfs are found to be the most stable with $ 2$). The variability fraction increases to $30\\%$ for the K dwarfs, 40\\% for the M and F dwarfs, and 70\\% for the A-dwarfs. At the precision of Kepler, $>95$\\% of K and G giants are variable with a noise floor of $\\sim 0.1$ mmag for the G-giants and 0.3 mmag for the K-giants. The photometric dispersion floor of the giants is consistent with acoustic variations of the photosphere; the photometrically-derived predicted radial velocity distribution for the K-giants is in agreement with the measured distribution; the G-giant radial velocity distribution is bi-modal which may indicate a transition from ...

  15. Preparation and characterization of bioadhesive controlled-release gels of cidofovir for vaginal delivery.

    Science.gov (United States)

    Tuğcu-Demiröz, Fatmanur; Acartürk, Füsun; Özkul, Aykut

    2015-01-01

    The aim of this study was to develop mucoadhesive and thermosensitive gels for vaginal delivery that would be able to provide a controlled release of the model drug, cidofovir. The study also monitored the drug's potential antiviral properties. Cidofovir was put into the form of a vaginal gel, using mucoadhesive and thermosensitive polymers such as chitosan, Carbopol 974P, HPMC, and poloxamer 407. The physicopharmaceutical properties and stability of the vaginal gel formulations were evaluated. The gel formulation which was prepared with HPMC K100M exhibited the highest viscosity, as well as maximum adhesiveness, cohesiveness, and mucoadhesion values. The results of antiviral activity studies, which used the bovine herpes virus type 1 virus infection in vitro model using Vero cells, demonstrated the antiherpetic effect of the cidofovir gel containing HPMC K100M, at least under in vitro conditions. The study found that a mucoadhesive vaginal gel containing cidofovir can be a promising and innovative alternative therapeutic system for the treatment of genital herpes simplex virus and human papilloma virus induced infections in women.

  16. Development and characterization of ethylcellulose based microsphere for sustained release of nifedipine$

    Institute of Scientific and Technical Information of China (English)

    Patitapabana Parida; Subash Chandra Mishra; Subhashree Sahoo; Ajit Behera; Bibhukalyan Prasad Nayak

    2016-01-01

    This article introduced the work of ethylcellulose based polymeric microsphere loaded with nifedipine for reduction in frequency of administration with low solubility in aqueous medium and high rate of absorption in the stomach. The non-aqueous polymeric suspension was put dropwise into an aqueous medium containing polyvinyl alcohol as a surfactant for the synthesis of microsphere by solvent eva-poration. The microspheres were characterized by different techniques, namely, XRD, SEM, and NMR. The formation of microspheres was confirmed by SEM. XRD analysis revealed the semi-crystallinity nature of microspheres. The NMR study indicated the presence of hetero-aromatic nucleus in the microsphere.

  17. Kinetic characterization of a novel endo-β-N-acetylglucosaminidase on concentrated bovine colostrum whey to release bioactive glycans.

    Science.gov (United States)

    Karav, Sercan; Parc, Annabelle Le; de Moura Bell, Juliana Maria Leite Nobrega; Rouquié, Camille; Mills, David A; Barile, Daniela; Block, David E

    2015-09-01

    EndoBI-1 is a recently isolated endo-β-N-acetylglucosaminidase, which cleaves the N-N'-diacetyl chitobiose moiety found in the N-glycan core of high mannose, hybrid and complex N-glycans. These N-glycans have selective prebiotic activity for a key infant gut microbe, Bifidobacterium longum subsp. infantis. The broad specificity of EndoBI-1 suggests the enzyme may be useful for many applications, particularly for deglycosylating milk glycoproteins in dairy processing. To facilitate its commercial use, we determined kinetic parameters for EndoBI-1 on the model substrates ribonuclease B and bovine lactoferrin, as well as on concentrated bovine colostrum whey. Km values ranging from 0.25 to 0.49, 0.43 to 1.00 and 0.90 to 3.18 mg/mL and Vmax values ranging from 3.5×10(-3) to 5.09×10(-3), 4.5×10(-3) to 7.75×10(-3) and 1.9×10(-2)to 5.2×10(-2) mg/mL×min were determined for ribonuclease B, lactoferrin and whey, respectively. In general, EndoBI-1 showed the highest apparent affinity for ribonuclease B, while the maximum reaction rate was the highest for concentrated whey. EndoBI-1-released N-glycans were quantified by a phenol-sulphuric total carbohydrate assay and the resultant N-glycan structures monitored by nano-LC-Chip-Q-TOF MS. The kinetic parameters and structural characterization of glycans released suggest EndoBI-1 can facilitate large-scale release of complex, bioactive glycans from a variety of glycoprotein substrates. Moreover, these results suggest that whey, often considered as a waste product, can be used effectively as a source of prebiotic N-glycans.

  18. Comparative characterization of two intracellular Ca²⁺-release channels from the red flour beetle, Tribolium castaneum.

    Science.gov (United States)

    Liu, Yaping; Li, Chengjun; Gao, Jingkun; Wang, Wenlong; Huang, Li; Guo, Xuezhu; Li, Bin; Wang, Jianjun

    2014-10-21

    Ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors (IP3Rs) are members of a family of tetrameric intracellular Ca(2+)-release channels (CRCs). While it is well known in mammals that RyRs and IP3Rs modulate multiple physiological processes, the roles of these two CRCs in the development and physiology of insects remain poorly understood. In this study, we cloned and functionally characterized RyR and IP3R cDNAs (named TcRyR and TcIP3R) from the red flour beetle, Tribolium castaneum. The composite TcRyR gene contains an ORF of 15,285 bp encoding a protein of 5,094 amino acid residues. The TcIP3R contains an 8,175 bp ORF encoding a protein of 2,724 amino acids. Expression analysis of TcRyR and TcIP3R revealed significant differences in mRNA expression levels among T. castaneum during different developmental stages. When the transcript levels of TcRyR were suppressed by RNA interference (RNAi), an abnormal folding of the adult hind wings was observed, while the RNAi-mediated knockdown of TcIP3R resulted in defective larval-pupal and pupal-adult metamorphosis. These results suggested that TcRyR is required for muscle excitation-contraction (E-C) coupling in T. castaneum, and that calcium release via IP3R might play an important role in regulating ecdysone synthesis and release during molting and metamorphosis in insects.

  19. Cubic phase nanoparticles for sustained release of ibuprofen formulation characterization and enhanced bioavailability study

    Directory of Open Access Journals (Sweden)

    Dian L

    2013-02-01

    Full Text Available Linghui Dian,1,2,* Zhiwen Yang,3,* Feng Li,1 Zhouhua Wang,1 Xin Pan,1 Xinsheng Peng,2 Xintian Huang,1 Zhefei Guo,1 Guilan Quan,1 Xuan Shi,1 Bao Chen,1 Ge Li,4 Chuanbin Wu1,41School of Pharmaceutical Sciences, Sun Yat-Sen University, University Town, Guangzhou, People’s Republic of China; 2School of Pharmaceutical Sciences, Guangdong Medical College, Dongguan, People’s Republic of China; 3Department of Gastroenterology, Songjiang Branch of the Affiliated First People’s Hospital of Shanghai Jiaotong University, Shanghai, People’s Republic of China; 4Guangdong Research Center for Drug Delivery Systems, Guangzhou, People’s Republic of China*These authors contributed equally to this workAbstract: In order to improve the oral bioavailability of ibuprofen, ibuprofen-loaded cubic nanoparticles were prepared as a delivery system for aqueous formulations. The cubic inner structure was verified by cryogenic transmission electron microscopy. With an encapsulation efficiency greater than 85%, the ibuprofen-loaded cubic nanoparticles had a narrow size distribution around a mean size of 238 nm. Differential scanning calorimetry and X-ray diffraction determined that ibuprofen was in an amorphous and molecular form within the lipid matrix. The in vitro release of ibuprofen from cubic nanoparticles was greater than 80% at 24 hours, showing sustained characteristics. The pharmacokinetic study in beagle dogs showed improved absorption of ibuprofen from cubic nanoparticles compared to that of pure ibuprofen, with evidence of a longer half-life and a relative oral bioavailability of 222% (P < 0.05. The ibuprofen-loaded cubic nanoparticles provide a promising carrier candidate with an efficient drug delivery for therapeutic treatment.Keywords: ibuprofen, cubic nanoparticles, oral drug delivery, bioavailability

  20. Characterization and release studies of liposomal gels containing glutathione/cyclodextrins complexes potentially useful for cutaneous administration.

    Science.gov (United States)

    Cutrignelli, Annalisa; Lopedota, Angela; Denora, Nunzio; Laquintana, Valentino; Tongiani, Serena; Franco, Massimo

    2014-04-01

    The aim of this work is to develop and characterize a formulation intended for the cutaneous administration of glutathione (γ-glutamylcysteinylglycine, GSH), potentially useful for cellular defense against UV-induced damage. For this purpose, liposomes containing GSH or GSH/cyclodextrins(CDs) inclusion complexes as well as liposomes dispersed within a hydrophilic gel, were evaluated. These formulations were designed in order to obtain a system combining the advantages of liposomes as vehicles for topical drug delivery with those of CDs as penetration enhancers. The studied CDs were the natural (β-CD) and chemically modified (i.e., HP-β-CD and CH3 -β-CD) cyclodextrins. The prepared liposomes showed homogeneous size distribution, mean diameter in the range 622-1435 nm, small positive charge (+3.1 to +6.6 mV), and encapsulation efficiency of the peptide in the range 13.6%-23.7%. Release studies showed that the presence of the oligosaccharide may influence to some extent the amount of drug released, whereas stability studies clearly point out that the incorporation in a hydrophilic gel of 2-hydroxyethylcellulose insures a stable formulation maintaining unchanged the characteristics of liposomal vesicles.

  1. Development and characterization of sustain release gastro retentive floating microsphere of diltiazem hydrochloride for the treatment of hypertension

    Directory of Open Access Journals (Sweden)

    Mangal S Panwar

    2015-01-01

    Full Text Available Gastroretentive drug delivery systems are the systems, which are retained in the stomach for a longer period and thereby improve the bio-availability of drugs. Diltiazem hydrochloride (DTZ HCl, is a calcium channel blocker, an antihypertension and antianginal drug, DTZ HCl undergoes an extensive biotransformation, mainly through cytochrome P-450 CYP3A, which results in <4% of its oral dose being excreted unchanged in urine. Suffers from poor bio-availability (~30-40% owing to an important first pass metabolism. It has an elimination half-life of 3.5 h and an absorption zone from the upper intestinal tract. Thus, the present work is aimed to formulate sustain release floating microsphere of DTZ HCl for gastroretentive drug delivery system. Floating microsphere were prepared using nonaqueous solvent evaporation method using polycarbonate, chitosan, ethyl cellulose, hydroxypropyl methycellulose and acrycoat as materials in various quantities, in varying ratio to formulate 20 formulations of the floating microsphere. Observations of all formulations for physical characterization had shown that, all of them comply with the specification of official pharmacopoeias and/or standard reference. It was observed that microsphere of batch F3 followed the results obtained, it was concluded that the formulation 98.72% F3 is the best formulations as the extent of drug release was found to be around 99.81% at the desired time 12 h.

  2. Formation and Biopharmaceutical Characterization of Electrospun PVP Mats with Propolis and Silver Nanoparticles for Fast Releasing Wound Dressing

    Directory of Open Access Journals (Sweden)

    Erika Adomavičiūtė

    2016-01-01

    Full Text Available Antibacterial, antiviral, antifungal, antioxidant, anti-inflammatory, and anticancer activities of propolis and its ability to stimulate the immune system and promote wound healing make it a proper component for wound dressing materials. Silver nanoparticles are recognized to demonstrate strong antiseptic and antimicrobial activity; thus, it also could be considered in the development of products for wound healing. Combining propolis and silver nanoparticles can result in improved characteristics of products designed for wound healing and care. The aim of this study was to formulate electrospun fast dissolving mats for wound dressing containing propolis ethanolic extract and silver nanoparticles. Produced electrospun nano/microfiber mats were evaluated studying their structure, dissolution rate, release of propolis phenolic compounds and silver nanoparticles, and antimicrobial activity. Biopharmaceutical characterization of electrospun mats demonstrated fast release of propolis phenolic compounds and silver nanoparticles. Evaluation of antimicrobial activity on Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus subtilis, Bacillus cereus, and Candida albicans strains confirmed the ability of electrospun mats to inhibit the growth of the tested microorganisms.

  3. Formation and Biopharmaceutical Characterization of Electrospun PVP Mats with Propolis and Silver Nanoparticles for Fast Releasing Wound Dressing.

    Science.gov (United States)

    Adomavičiūtė, Erika; Stanys, Sigitas; Žilius, Modestas; Juškaitė, Vaida; Pavilonis, Alvydas; Briedis, Vitalis

    2016-01-01

    Antibacterial, antiviral, antifungal, antioxidant, anti-inflammatory, and anticancer activities of propolis and its ability to stimulate the immune system and promote wound healing make it a proper component for wound dressing materials. Silver nanoparticles are recognized to demonstrate strong antiseptic and antimicrobial activity; thus, it also could be considered in the development of products for wound healing. Combining propolis and silver nanoparticles can result in improved characteristics of products designed for wound healing and care. The aim of this study was to formulate electrospun fast dissolving mats for wound dressing containing propolis ethanolic extract and silver nanoparticles. Produced electrospun nano/microfiber mats were evaluated studying their structure, dissolution rate, release of propolis phenolic compounds and silver nanoparticles, and antimicrobial activity. Biopharmaceutical characterization of electrospun mats demonstrated fast release of propolis phenolic compounds and silver nanoparticles. Evaluation of antimicrobial activity on Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus subtilis, Bacillus cereus, and Candida albicans strains confirmed the ability of electrospun mats to inhibit the growth of the tested microorganisms.

  4. Purification and Characterization of a Unique Pectin Lyase from Aspergillus giganteus Able to Release Unsaturated Monogalacturonate during Pectin Degradation.

    Science.gov (United States)

    Pedrolli, Danielle Biscaro; Carmona, Eleonora Cano

    2014-01-01

    A pectin lyase, named PLIII, was purified to homogeneity from the culture filtrate of Aspergillus giganteus grown in submerged culture containing orange peel waste as carbon source. PLIII was able to digest apple pectin and citrus pectins with different degrees of methyl esterification. Interestingly, the PLIII activity was stimulated in the presence of some divalent cations including Pb(2+) and was not significantly affected by Hg(2+). Like other pectin lyases, PLIII is stimulated by but is not dependent on Ca(2+). The main soluble product released during the degradation of pectic substances promoted by the PLIII is compatible with an unsaturated monogalacturonate. PLIII is a unique enzyme able to release unsaturated monogalacturonate as the only soluble product during the degradation of pectic substances; therefore, PLIII was classified as an exo-pectin lyase. To our knowledge, this is the first characterization of an exo-pectin lyase. The PLIII described in this work is potentially useful for ethanol production from pectin-rich biomass, besides other common applications for alkaline pectinases like preparation of textile fibers, coffee and tea fermentation, vegetable oil extraction, and the treatment of pulp in papermaking.

  5. Purification and Characterization of a Unique Pectin Lyase from Aspergillus giganteus Able to Release Unsaturated Monogalacturonate during Pectin Degradation

    Directory of Open Access Journals (Sweden)

    Danielle Biscaro Pedrolli

    2014-01-01

    Full Text Available A pectin lyase, named PLIII, was purified to homogeneity from the culture filtrate of Aspergillus giganteus grown in submerged culture containing orange peel waste as carbon source. PLIII was able to digest apple pectin and citrus pectins with different degrees of methyl esterification. Interestingly, the PLIII activity was stimulated in the presence of some divalent cations including Pb2+ and was not significantly affected by Hg2+. Like other pectin lyases, PLIII is stimulated by but is not dependent on Ca2+. The main soluble product released during the degradation of pectic substances promoted by the PLIII is compatible with an unsaturated monogalacturonate. PLIII is a unique enzyme able to release unsaturated monogalacturonate as the only soluble product during the degradation of pectic substances; therefore, PLIII was classified as an exo-pectin lyase. To our knowledge, this is the first characterization of an exo-pectin lyase. The PLIII described in this work is potentially useful for ethanol production from pectin-rich biomass, besides other common applications for alkaline pectinases like preparation of textile fibers, coffee and tea fermentation, vegetable oil extraction, and the treatment of pulp in papermaking.

  6. Preparation and Characterization of Nano-silver Loaded Montmorillonite with Strong Antibacterial Activity and Slow Release Property

    Institute of Scientific and Technical Information of China (English)

    Guangnian Xu; Xueliang Qiao; Xiaolin Qiu; Jianguo Chen

    2011-01-01

    Nano-silver loaded montmorillonite (Ag-MMT) was prepared by ion-exchange and then a UV-photoreduction two-step approach was applied. The silver content in Ag-MMT determined by Volhard method was about 6.4 wt%. The morphology and structure of as-synthesized Ag-MMT were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the Ag nanoparticles were spherical and their diameters were about 15-20 nm. Moreover, the structure of MMT did not change. The minimum inhibition concentration (MIC) of Ag-MMT was 100×10-6 and the sterilizing efficiency (SE) of Ag-MMT was approximately 100% against Escherichia coli ATCC 11229 (E. coli. In addition, the slow release property of silver in Ag-MMT was also demonstrated.

  7. Polymeric formulations for drug release prepared by hot melt extrusion: application and characterization.

    Science.gov (United States)

    Stanković, Milica; Frijlink, Henderik W; Hinrichs, Wouter L J

    2015-07-01

    Over the past few decades hot melt extrusion (HME) has emerged as a powerful processing technology for the production of pharmaceutical solid dosage forms in which an active pharmaceutical ingredient (API) is dispersed into polymer matrices. It has been shown that formulations using HME can provide time-controlled, sustained and targeted drug delivery, and improved bioavailability of poorly soluble drugs. In this review, the basic principles of the HME process are described together with an overview of some of the most common biodegradable and nonbiodegradable polymers used for the preparation of different formulations using this method. Further, the applications of HME in drug delivery and analytical techniques employed to characterize HME products are addressed.

  8. Distributed micro-releases of bioterror pathogens : threat characterizations and epidemiology from uncertain patient observables.

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Michael M. (University of Illinois, Urbana-Champaign, Urbana, IL); Marzouk, Youssef M.; Adams, Brian M.; Devine, Karen Dragon; Ray, Jaideep; Najm, Habib N.

    2008-10-01

    Terrorist attacks using an aerosolized pathogen preparation have gained credibility as a national security concern since the anthrax attacks of 2001. The ability to characterize the parameters of such attacks, i.e., to estimate the number of people infected, the time of infection, the average dose received, and the rate of disease spread in contemporary American society (for contagious diseases), is important when planning a medical response. For non-contagious diseases, we address the characterization problem by formulating a Bayesian inverse problem predicated on a short time-series of diagnosed patients exhibiting symptoms. To keep the approach relevant for response planning, we limit ourselves to 3.5 days of data. In computational tests performed for anthrax, we usually find these observation windows sufficient, especially if the outbreak model employed in the inverse problem is accurate. For contagious diseases, we formulated a Bayesian inversion technique to infer both pathogenic transmissibility and the social network from outbreak observations, ensuring that the two determinants of spreading are identified separately. We tested this technique on data collected from a 1967 smallpox epidemic in Abakaliki, Nigeria. We inferred, probabilistically, different transmissibilities in the structured Abakaliki population, the social network, and the chain of transmission. Finally, we developed an individual-based epidemic model to realistically simulate the spread of a rare (or eradicated) disease in a modern society. This model incorporates the mixing patterns observed in an (American) urban setting and accepts, as model input, pathogenic transmissibilities estimated from historical outbreaks that may have occurred in socio-economic environments with little resemblance to contemporary society. Techniques were also developed to simulate disease spread on static and sampled network reductions of the dynamic social networks originally in the individual-based model

  9. Characterization of polycyclic aromatic hydrocarbons and metals in ashes released from a forest fire

    Science.gov (United States)

    Campos, I.; Abrantes, N.; Pereira, P.; Vale, C.; Ferreira, A.; Keizer, J. J.

    2012-04-01

    Wildfires have become a permanent source of environmental and societal concerns. Whilst the impacts of wildfire on hydrological and erosion processes are well documented, the stocks and export of polycyclic aromatic hydrocarbons (PAHs) and heavy metals have received considerably less research attention. The ashes produced by wildfires, which include polluting substances such as PAHs and metals, are subject to transport processes by wind and especially by overland flow and water infiltrating into the soil and possibly reaching ground water bodies. In the framework of the FIRECNUTS project, we are studying the stocks of PAHs and selected metals in recently burnt forest stands in north-central Portugal, and their subsequent export by overland flow. The present work, however, will focus on the stocks in the ashes, both immediately after wildfire and three months later. These ashes were collected at two burnt slopes with contrasting forest types, i.e. a eucalypt and a maritime pine stand, the two pre-dominant forest types in the study region. The sixteen PAHs identified by US EPA as priority contaminants were analysed by gas chromatograph, after extraction and column clean up. The contents of vanadium (V), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) were analysed by inductively coupled plasma- mass spectrometry (ICP-MS), after an acid digestion, while mercury (Hg) was analysed by pyrolysis atomic absorption spectrometry with gold amalgamation. The total concentration of PAHs immediately after the wildfire ranged from 314 ng/g dry weight in the maritime pine stand to 597 ng/g dry weight in the eucalypt stand. Three months later, the total concentration has decreased with 33% in the pine stand but only half (16%) in the eucalypt stand. The composition the PAHs by ring size was dominated by three-rings PAHs. This was true for all samples. The concentrations of various metals differed for the two sampling

  10. Synthesis of large FeSe superconductor crystals via ion release/introduction and property characterization

    Institute of Scientific and Technical Information of China (English)

    苑冬娜; 董晓莉; 周放; 黄裕龙; 倪顺利; 周花雪; 毛义元; 胡卫; 袁洁; 金魁; 张广铭

    2016-01-01

    Large superconducting FeSe crystals of (001) orientation have been prepared via a hydrothermal ion re-lease/introduction route for the first time. The hydrothermally derived FeSe crystals are up to 10 mm×5 mm×0.3 mm in dimension. The pure tetragonal FeSe phase has been confirmed by x-ray diffraction (XRD) and the composition de-termined by both inductively coupled plasma atomic emission spectroscopy (ICP-AES) and energy dispersive x-ray spec-troscopy (EDX). The superconducting transition of the FeSe samples has been characterized by magnetic and transport measurements. The zero-temperature upper critical field Hc2 is calculated to be 13.2–16.7 T from a two-band model. The normal-state cooperative paramagnetism is found to be predominated by strong spin frustrations below the characteris-tic temperature Tsn, where the Ising spin nematicity has been discerned in the FeSe superconductor crystals as reported elsewhere.

  11. Hydrologic characterization of the Fry Canyon, Utah site prior to field demonstration of reactive chemical barriers to control radionuclide and trace-element contamination in ground water

    Energy Technology Data Exchange (ETDEWEB)

    Naftz, D.L.; Freethey, G.W. [Geological Survey, Salt Lake City, UT (United States); Davis, J.A. [Geological Survey, Menlo Park, CA (United States)] [and others

    1997-12-31

    The Fry Canyon Site in southeastern Utah has been selected as a long term demonstration site to assess the performance of selected reaction barrier technologies for the removal of uranium and other trace elements from ground water. Objectives include site characterization and evaluation of barrier technologies.

  12. Ground-based characterization of Eurybates and Orus, two fly-by targets of the Lucy Discovery mission

    Science.gov (United States)

    Mottola, Stefano; Marchi, Simone; Buie, Marc W.; Hellmich, Stephan; Di Martino, Mario; Proffe, Gerrit; Levison, Harold F.; Zangari, Amanda Marie

    2016-10-01

    Lucy is a proposed NASA Discovery mission designed to perform close fly-bys with six Jupiter Trojan asteroids. The mission, which is currently in the Phase A development phase, is planned to launch in 2021 and arrive at the Trojan L4 cloud in 2027.We report on ground-based light curve observations of two of Lucy's fly-by target candidates: (3548) Eurybates and (21900) Orus. The goal is to characterize their shape, spin state and photometric properties both to aid in the planning of the mission, and to complement the space-borne data.Each object has been observed over 5 apparitions in a wide range of geocentric ecliptic longitudes. Shape and spin state modeling was performed by using the convex shape inversion method (Kaasalainen, Mottola & Fulchignoni, 2002). Eurybates is a retrograde rotator with a sidereal rotation Psid=8.702724±0.000009 h. It has a moderately elongated shape with equivalent axial ratios a/b=1.08, b/c=1.16. No obvious signs of global non-convexities and/or albedo variegation are detected in its light curves. Orus is also a retrograde rotator with a period Psid=13.48617±0.00007 h. Its approximate axial ratios are a/b=1.14, b/c=1.12. The presence of a large, planar facet in the proximity of the model's North Pole suggests the presence of a large polar crater.

  13. Preparation, Characterization and in vivo Evaluation of Simple Monolithic Ethylcellulose-coated Pellets Containing Topiramate with Biphasic Release Characteristics.

    Science.gov (United States)

    Gong, Wei; Wang, Yuli; Shao, Shuai; Xie, Si; Shan, Li; Yang, Meiyan; Gao, Chunsheng; Zhong, Wu

    2016-01-01

    In our previous study, polyvinylpyrrolidone (PVP) was used both as a binder and a pore-former to prepare ethylcellulose (EC)-coated pellets to deliver topiramate (TPM) for a controlled release profile. The objective of this work was to further optimize the formulation and evaluate the in vivo profiles of TPM sustained-release pellets. Similar to the previous formulation with no binder, the in vitro drug release of TPM sustained-release pellets with 50% PVP binder in drug layer was sensitive to pore-former PVP level ranged from 27.0% to 29.0%. The higher the level of PVP was, the quicker release rate in vitro was. Moreover, when the proportion of poreformer PVP decreased, the Cmax decreased, and the tmax and mean residence time of TPM coated pellets were both prolonged. The in vitro release profile of optimal formulation showed biphasic release characteristics similar to reference formulation Trokendi XR(®), i.e., involving immediate release of TPM in initial release stage followed by a sustained release up to 24 h. Moreover, the impact of the pH of release medium on the drug release rate of TPM sustained-release pellets was not significant. The release mechanism of TPM from the sustained-release pellets might be the interaction of diffusion (coating-film) and corrosion (drug layer). The in vivo pharmacokinetics results showed the TPM sustained-release pellets had the similar in vivo pattern compared with Trokendi XR(®). These studies provide valuable basis for further development of TPM sustained-release pellets.

  14. The Bubble Box: Towards an Automated Visual Sensor for 3D Analysis and Characterization of Marine Gas Release Sites.

    Science.gov (United States)

    Jordt, Anne; Zelenka, Claudius; von Deimling, Jens Schneider; Koch, Reinhard; Köser, Kevin

    2015-12-05

    Several acoustic and optical techniques have been used for characterizing natural and anthropogenic gas leaks (carbon dioxide, methane) from the ocean floor. Here, single-camera based methods for bubble stream observation have become an important tool, as they help estimating flux and bubble sizes under certain assumptions. However, they record only a projection of a bubble into the camera and therefore cannot capture the full 3D shape, which is particularly important for larger, non-spherical bubbles. The unknown distance of the bubble to the camera (making it appear larger or smaller than expected) as well as refraction at the camera interface introduce extra uncertainties. In this article, we introduce our wide baseline stereo-camera deep-sea sensor bubble box that overcomes these limitations, as it observes bubbles from two orthogonal directions using calibrated cameras. Besides the setup and the hardware of the system, we discuss appropriate calibration and the different automated processing steps deblurring, detection, tracking, and 3D fitting that are crucial to arrive at a 3D ellipsoidal shape and rise speed of each bubble. The obtained values for single bubbles can be aggregated into statistical bubble size distributions or fluxes for extrapolation based on diffusion and dissolution models and large scale acoustic surveys. We demonstrate and evaluate the wide baseline stereo measurement model using a controlled test setup with ground truth information.

  15. The Bubble Box: Towards an Automated Visual Sensor for 3D Analysis and Characterization of Marine Gas Release Sites

    Directory of Open Access Journals (Sweden)

    Anne Jordt

    2015-12-01

    Full Text Available Several acoustic and optical techniques have been used for characterizing natural and anthropogenic gas leaks (carbon dioxide, methane from the ocean floor. Here, single-camera based methods for bubble stream observation have become an important tool, as they help estimating flux and bubble sizes under certain assumptions. However, they record only a projection of a bubble into the camera and therefore cannot capture the full 3D shape, which is particularly important for larger, non-spherical bubbles. The unknown distance of the bubble to the camera (making it appear larger or smaller than expected as well as refraction at the camera interface introduce extra uncertainties. In this article, we introduce our wide baseline stereo-camera deep-sea sensor bubble box that overcomes these limitations, as it observes bubbles from two orthogonal directions using calibrated cameras. Besides the setup and the hardware of the system, we discuss appropriate calibration and the different automated processing steps deblurring, detection, tracking, and 3D fitting that are crucial to arrive at a 3D ellipsoidal shape and rise speed of each bubble. The obtained values for single bubbles can be aggregated into statistical bubble size distributions or fluxes for extrapolation based on diffusion and dissolution models and large scale acoustic surveys. We demonstrate and evaluate the wide baseline stereo measurement model using a controlled test setup with ground truth information.

  16. Synthesis and characterization of superabsorbent polymer prepared by radiation-induced graft copolymerization of acrylamide onto carboxymethyl cellulose for controlled release of agrochemicals

    Science.gov (United States)

    Hemvichian, Kasinee; Chanthawong, Auraruk; Suwanmala, Phiriyatorn

    2014-10-01

    Superabsorbent polymer (SAP) was synthesized by radiation-induced grafting of acrylamide (AM) onto carboxymethyl cellulose (CMC) in the presence of a crosslinking agent, N,N‧-methylenebisacrylamide (MBA). The effects of various parameters, such as dose, the amount of CMC, AM, MBA and ionic strength on the swelling ratio were investigated. In order to evaluate its controlled release potential, SAP was loaded with potassium nitrate (KNO3) as an agrochemical model and its potential for controlled release of KNO3 was studied. The amount of released KNO3 was analyzed by an inductively coupled plasma mass spectrometry (ICP-MS). The results from controlled release experiment agreed very well with the results from swelling experiment. The synthesized SAP was characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The obtained SAP exhibited a swelling ratio of 190 g/g of dry gel.

  17. The characterization of the quasi-enveloped hepatitis E virus particles released by the cellular exosomal pathway.

    Science.gov (United States)

    Nagashima, Shigeo; Takahashi, Masaharu; Kobayashi, Tominari; Tanggis; Nishizawa, Tsutomu; Nishiyama, Takashi; Primadharsini, Putu Prathiwi; Okamoto, Hiroaki

    2017-09-06

    Our previous studies demonstrated that membrane-associated hepatitis E virus (HEV) particles-now considered "quasi-enveloped particles"-are present in the multivesicular body with intraluminal vesicles (exosomes) in infected cells, and that the release of HEV virions is related to the exosomal pathway. In this study, we characterized exosomes purified from culture supernatant of HEV-infected PLC/PRF/5 cells. Purified CD63-, CD9-, or CD81-positive exosomes derived from the culture supernatant of HEV-infected cells that had been cultivated in serum-free medium were found to contain HEV RNA and the viral capsid (ORF2) and ORF3 proteins, as determined by a RT-PCR and Western blotting, respectively. Furthermore, immunoelectron microscopy, with or without prior detergent and protease treatment, revealed the presence of virus-like particles in the exosome fraction. These particles were 39.6 ± 1.0 nm in diameter, and were covered with a lipid membrane. After treatment with detergent and protease, the diameter of these virus-like particles was 26.9 ± 0.9 nm, and the treated particles became accessible with an anti-HEV ORF2 monoclonal antibody (mAb). The HEV particles in the exosome fraction were capable of infecting native PLC/PRF/5 cells, but were not neutralized by an anti-HEV ORF2 mAb, which can efficiently neutralize the non-enveloped HEV particles in cell culture. These results indicate that the membrane-wrapped HEV particles released by the exosomal pathway are co-purified with the exosomes in the exosome fraction, and suggest that the capsids of HEV particles are individually covered by lipid membranes resembling those of exosomes, similarly to enveloped viruses.IMPORTANCE Hepatitis E, caused by HEV, is an important infectious disease that is spreading worldwide. HEV infection can cause acute or fulminant hepatitis and can become chronic in immunocompromised hosts, including patients after organ transplantation. The HEV particles present in feces and bile are non

  18. Characterization of downwelling radiance measured from a ground-based microwave radiometer using numerical weather prediction model data

    Science.gov (United States)

    Ahn, M.-H.; Won, H. Y.; Han, D.; Kim, Y.-H.; Ha, J.-C.

    2016-01-01

    The ground-based microwave sounding radiometers installed at nine weather stations of Korea Meteorological Administration alongside with the wind profilers have been operating for more than 4 years. Here we apply a process to assess the characteristics of the observation data by comparing the measured brightness temperature (Tb) with reference data. For the current study, the reference data are prepared by the radiative transfer simulation with the temperature and humidity profiles from the numerical weather prediction model instead of the conventional radiosonde data. Based on the 3 years of data, from 2010 to 2012, we were able to characterize the effects of the absolute calibration on the quality of the measured Tb. We also showed that when clouds are present the comparison with the model has a high variability due to presence of cloud liquid water therefore making cloudy data not suitable for assessment of the radiometer's performance. Finally we showed that differences between modeled and measured brightness temperatures are unlikely due to a shift in the selection of the center frequency but more likely due to spectroscopy issues in the wings of the 60 GHz absorption band. With a proper consideration of data affected by these two effects, it is shown that there is an excellent agreement between the measured and simulated Tb. The regression coefficients are better than 0.97 along with the bias value of better than 1.0 K except for the 52.28 GHz channel which shows a rather large bias and variability of -2.6 and 1.8 K, respectively.

  19. Pharmacological and ionic characterizations of the muscarinic receptors modulating (/sup 3/H)acetylcholine release from rat cortical synaptosomes

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, E.M.; Otero, D.H.

    1985-05-01

    The muscarinic receptors that modulate acetylcholine release from rat cortical synaptosomes were characterized with respect to sensitivity to drugs that act selectively at M1 or M2 receptor subtypes, as well as to changes in ionic strength and membrane potential. The modulatory receptors appear to be of the M2 type, since they are activated by carbachol, acetylcholine, methacholine, oxotremorine, and bethanechol, but not by pilocarpine, and are blocked by atropine, scopolamine, and gallamine (at high concentrations), but not by pirenzepine or dicyclomine. The ED50S for carbachol, acetylcholine, and oxotremorine are less than 10 microM, suggesting that the high affinity state of the receptor is functional. High ionic strength induced by raising the NaCl concentration has no effect on agonist (oxotremorine) potency, but increases the efficacy of this compound, which disagrees with receptor-binding studies. On the other hand, depolarization with either KCl or with veratridine (20 microM) reduces agonist potencies by approximately an order of magnitude, suggesting a potential mechanism for receptor regulation.

  20. Characterizing exogenous mRNA delivery, trafficking, cytoplasmic release and RNA-protein correlations at the level of single cells.

    Science.gov (United States)

    Kirschman, Jonathan L; Bhosle, Sushma; Vanover, Daryll; Blanchard, Emmeline L; Loomis, Kristin H; Zurla, Chiara; Murray, Kathryn; Lam, Blaine C; Santangelo, Philip J

    2017-07-07

    The use of synthetic messenger ribonucleic acid (mRNA) to express specific proteins is a highly promising therapeutic and vaccine approach that avoids many safety issues associated with viral or DNA-based systems. However, in order to optimize mRNA designs and delivery, technology advancements are required to study fundamental mechanisms of mRNA uptake and localization at the single-cell and tissue level. Here, we present a single RNA sensitive fluorescent labeling method which allows us to label and visualize synthetic mRNA without significantly affecting function. This approach enabled single cell characterization of mRNA uptake and release kinetics from endocytic compartments, the measurement of mRNA/protein correlations, and motivated the investigation of mRNA induced cellular stress, all important mechanisms influencing protein production. In addition, we demonstrated this approach can facilitate near-infrared imaging of mRNA localization in vivo and in ex-vivo tissue sections, which will facilitate mRNA trafficking studies in pre-clinical models. Overall, we demonstrate the ability to study fundamental mechanisms necessary to optimize delivery and therapeutic strategies, in order to design the next generation of novel mRNA therapeutics and vaccines. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  1. Release and characterization of single side chains of white cabbage pectin and their complement-fixing activity.

    Science.gov (United States)

    Westereng, Bjorge; Coenen, Gerd Jan; Michaelsen, Terje Einar; Voragen, Alphons G J; Samuelsen, Anne Berit; Schols, Henk A; Knutsen, Svein Halvor

    2009-06-01

    A mixture of single side chains from white cabbage pectin were obtained by anion exchange chromatography after applying mild chemical conditions promoting beta-elimination. These pectin fragments were characterized by their molecular weight distribution, sugar composition, 13C-NMR, and MALDI-TOF-MS analysis. These analyses revealed that the large oligosaccharides released by beta-eliminative treatment were composed of alpha-1,5 linked arabinosyl residues with 2- and 3-linked alpha-arabinosyl side chains, and, or beta-1,4 linked galactosyl side chains. Fractions were tested for complement-fixing activity in order to determine their interaction with the complement system. These results strongly indicated that there was a minimal unit size responsible for the complement-fixing activity. Neutral pectin fragments (8 kDa) obtained from beta-elimination were inactive in the complement system, although they contained a sugar composition previously shown to be highly active. Larger pectin fragments (17 kDa) retained some activity, but much lower than polymers containing rhamnogalacturonan type 1 (RGI) structures isolated from the same source. This implied that structural elements containing multiple side chains is necessary for efficient complement-fixing activity.

  2. Ground-water characterization field activities for 1995--1996 Laboratory for Energy-Related Health Research, University of California, Davis

    Energy Technology Data Exchange (ETDEWEB)

    Liikala, T.L.; Lanigan, D.C.; Last, G.V. [and others

    1996-05-01

    This report documents ground-water characterization field activities completed from August to December 1995 and in January 1996 at the Laboratory for Energy-Related Health Research (LEHR) in Davis, California. The ground water at LEHR is one of several operable units under investigation by Pacific Northwest National Laboratory for the US Department of Energy. The purpose of this work was to further characterize the hydrogeology beneath the LEHR site, with the primary focus on ground water. The objectives were to estimate hydraulic properties for the two uppermost saturated hydrogeologic units (i.e., HSU-1 and HSU-2), and to determine distributions of contaminants of concern in these units. Activities undertaken to accomplish these objectives include well installation, geophysical logging, well development, ground-water sampling, slug testing, Westbay ground-water monitoring system installation, continuous water-level monitoring, Hydropunch installation, and surveying. Ground-water samples were collected from 61 Hydropunch locations. Analytical results from these locations and the wells indicate high chloroform concentrations trending from west/southwest to east/northeast in the lower portion of HSU-1 and in the upper and middle portions of HSU-2. The chloroform appears to originate near Landfill 2. Tritium was not found above the MCL in any of the well or Hydropunch samples. Hexavalent chromium was found at four locations with concentrations above the MCL in HSU-1 and at one location in HSU-2. One well in HSU-1 had a total chromium concentration above the MCL. Nitrate-nitrogen above the MCL was found at several Hydropunch locations in both HSU-1 and HSU-2.

  3. SURFACE GEOPHYSICAL EXPLORATION OF TX-TY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH GROUND PENETRATING RADAR

    Energy Technology Data Exchange (ETDEWEB)

    MYERS DA; CUBBAGE R; BRAUCHLA R; O' BRIEN G

    2008-07-24

    Ground penetrating radar surveys of the TX and TY tank farms were performed to identify existing infrastructure in the near surface environment. These surveys were designed to provide background information supporting Surface-to-Surface and Well-to-Well resistivity surveys of Waste Management Area TX-TY. The objective of the preliminary investigation was to collect background characterization information with GPR to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity{trademark} surveys. The results of the background characterization confirm the existence of documented infrastructure, as well as highlight locations of possible additional undocumented subsurface metallic objects.

  4. Characterization of endocrine events during the periestrous period in sheep after estrous synchronization with controlled internal drug release (CIDR) device.

    Science.gov (United States)

    Van Cleeff, J; Karsch, F J; Padmanabhan, V

    1998-01-01

    The Controlled Internal Drug Releasing (CIDR) device is an intravaginal pessary containing progesterone (P4) designed for synchronizing estrus in ruminants. To date, there has been little information available on the timing, duration, and quality of the follicular phase after CIDR removal and how those characteristics compare with natural periovulatory endocrine events. The present communication relates the results of methods we used to characterize the endocrine events that followed CIDR synchronization. Breeding-season ewes were given an injection (10 mg) of Lutalyse (PGF2 alpha), and then studied during three consecutive estrous cycles, beginning in the luteal phase after the estrus induced by PGF2 alpha. Cycle 1 estrus was synchronized with 1 CIDR (Type G) inserted for 8 d beginning 10 d after PGF2 alpha. Cycles 2 and 3 were synchronized with two CIDRs for 8 d beginning 10 d after previous CIDR removal. Cycle 1 estrous behavior and serum gonadotropins showed a follicular phase (the interval from CIDR withdrawal to gonadotropin surge [surge] peak) of 38.2 +/- 1.5 hr. Two CIDRs lengthened the interval to 46.2 +/- 1.5 hr (P synchronization concentrated surges within a 24-hr period in 92% of the ewes in Cycles 1 and 2. Cycles 3 ewes were euthanized at estimated luteal, early follicular, late follicular, LH surge, and secondary FSH rise timepoints. Endocrine data and ovaries showed that 88% of the ewes synchronized with two CIDRs were in the predicted stage of the estrous cycle. These data demonstrate that the CIDR device applied during the luteal phase effectively synchronizes estrus and results in a CIDR removal-to-surge interval of similar length to a natural follicular phase.

  5. PREPARATION, CHARACTERIZATION AND PHARMACEUTICAL APPLICATION OF LINEAR DEXTRINS .4. DRUG-RELEASE FROM CAPSULES AND TABLETS CONTAINING AMYLODEXTRIN

    NARCIS (Netherlands)

    WIERIK, GHPT; EISSENS, AC; LERK, CF

    1993-01-01

    Linear dextrin (amylodextrin) and its soluble fraction were investigated for their suitability to enhance diazepam release from capsules and tablets. Drug release was analyzed in the USP XXI paddle apparatus and performed in phosphate buffer pH 6.8, with and without alpha-amylase, and in 0.1 N HCl s

  6. Formulation and In Vitro Characterization of Xanthan Gum-Based Sustained Release Matrix Tables of Isosorbide-5- Mononitrate

    Science.gov (United States)

    Kar, Rajat; Mohapatra, Snehamayee; Bhanja, Satyabrata; Das, Debjyoti; Barik, Bhaktibhusan

    2010-01-01

    In the present investigation an attempt has been made to increase therapeutic efficacy, to reduce frequency of administration and to improve patient compliance by developing a sustained release matrix tablets of isosorbide-5-mononitrate. Sustained release matrix tablets of isosorbide-5-mononitrate were developed by using different drug: polymer ratios, such in F1 (1:0.75), F2 (1:1), F3 (1:1.5), F4 (1:1.75) and F6 (1:2). Xanthan gum was used as matrix former and microcrystalline cellulose as diluent. All the lubricated formulations were compressed, using 8mm flat faced punches. Compressed tablets were evaluated for uniformity of weight, content of active ingredient, friability, hardness, thickness, in vitro dissolution study using basket method and swelling index. Each formulation showed compliance with pharmacopoeial standards. Among all formulations, F5 showed a greater sustained release pattern of drug over a 12 h period with 92.12% of drug being released. The kinetic studies showed that drug release follows the Higuchi model (r2 =0.9851). Korsemeyer and Peppas equation gave an n-value of 0.4566, which was close to 0.5, indicating that drug release follows the Fickian diffusion. Thus, xanthan gum can be used as an effective matrix former to extend the release of isosorbide-5-mononitrate. No significant difference was observed in the dissolution profile of optimized formulation, using basket and paddle apparatus. PMID:24363701

  7. Preparation and characterization of PHBV microsphere/45S5 bioactive glass composite scaffolds with vancomycin releasing function.

    Science.gov (United States)

    Li, Wei; Ding, Yaping; Rai, Ranjana; Roether, Judith A; Schubert, Dirk W; Boccaccini, Aldo R

    2014-08-01

    PHBV microsphere/45S5 bioactive glass (BG) composite scaffolds with drug release function were developed for bone tissue engineering. BG-based glass-ceramic scaffolds with high porosity (94%) and interconnected pore structure prepared by foam replication method were coated with PHBV microspheres (nominal diameter=3.5 μm) produced by water-in-oil-in-water double emulsion solvent evaporation method. A homogeneous microsphere coating throughout the porous structure of scaffolds was obtained by a simple dip coating method, using the slurry of PHBV microspheres in hexane. Compressive strength tests showed that the microsphere coating slightly improved the mechanical properties of the scaffolds. It was confirmed that the microsphere coating did not inhibit the bioactivity of the scaffolds in SBF. Hydroxyapatite crystals homogeneously grew not only on the struts of the scaffolds but also on the surface of microspheres within 7 days of immersion in SBF. Vancomycin was successfully encapsulated into the PHBV microspheres. The encapsulated vancomycin was released with a dual release profile involving a relatively low initial burst release (21%) and a sustained release (1 month), which is favorable compared to the high initial burst release (77%) and short release period (4 days) measured on uncoated scaffolds. The developed bioactive composite scaffold with drug delivery function has thus the potential to be used advantageously in bone tissue engineering.

  8. Cell wall polysaccharides released during the alcoholic fermentation by Schizosaccharomyces pombe and S. japonicus: quantification and characterization.

    Science.gov (United States)

    Domizio, P; Liu, Y; Bisson, L F; Barile, D

    2017-02-01

    The present work demonstrates that yeasts belonging to the Schizosaccharomyces genus release a high quantity of polysaccharides of cell wall origin starting from the onset of the alcoholic fermentation. By the end of the alcoholic fermentation, all of the Schizosaccharomyces yeast strains released a quantity of polysaccharides approximately 3-7 times higher than that released by a commercial Saccharomyces cerevisiae yeast strain under the same fermentative conditions of synthetic juice. A higher content of polysaccharide was found in media fermented by Schizosaccharomyces japonicus with respect to that of Schizosaccharomyces pombe. Some of the strains evaluated were also able to produce high levels of pyruvic acid, which has been shown to be an important compound for color stability of wine. The presence of strains with different malic acid consumption patterns along with high polysaccharide release would enable production of naturally modified wines with enhanced mouth feel and reduced acidity. The chemical analysis of the released polysaccharides demonstrated divergence between the two yeast species S. pombe and S. japonicus. A different mannose/galactose ratio and a different percentage of proteins was observed on the polysaccharides released by S. pombe as compared to S. japonicus. Analysis of the proteins released in the media revealed the presence of a glycoprotein with a molecular size around 32-33 kDa only for the species S. japonicus. Mass spectrometry analysis of carbohydrate moieties showed similar proportions among the N-glycan chains released in the media by both yeast species but differences between the two species were also observed. These observations suggest a possible role of rapid MALDI-TOF screening of N-glycans compositional fingerprint as a taxonomic tool for this genus. Polysaccharides release in the media, in particular galactomannoproteins in significant amounts, could make these yeasts particularly interesting also for the industrial

  9. Pharmacological characterization of dopamine, norepinephrine and serotonin release in the rat prefrontal cortex by neuronal nicotinic acetylcholine receptor agonists.

    Science.gov (United States)

    Rao, Tadimeti S; Correa, Lucia D; Adams, Pamala; Santori, Emily M; Sacaan, Aida I

    2003-11-14

    Neuronal nicotinic acetylcholine receptors (nAChRs) modulate synaptic transmission by regulating neurotransmitter release, an action that involves multiple nAChRs. The effects of four nAChR agonists, nicotine (NIC), 1,1-dimethyl-4-phenylpiperzinium iodide (DMPP), cytisine (CYT) and epibatidine (EPI) were investigated on [3H]-norepinephrine (NE), [3H]-dopamine (DA) and [3H]-serotonin (5-HT) release from rat prefrontal cortical (PFC) slices. All four agonists evoked [3H]-DA release to a similar magnitude but with a differing rank order of potency of EPI>DMPP approximately NIC approximately CYT. Similarly, all four agonists also increased [3H]-NE release, but with a differing rank order of potency of EPI>CYT approximately DMPP>NIC. NIC-induced [3H]-NE and [3H]-DA release responses were both calcium-dependent and attenuated by the sodium channel antagonist, tetrodotoxin (TTX) and by the nAChR antagonists mecamylamine (MEC) and dihydro-beta-erythroidine (DHbetaE), but not by D-tubocurare (D-TC). The modulation of [3H]-5-HT release by nAChR agonists was distinct from that seen for catecholamines. DMPP produced robust increases with minimal release observed with other agonists. DMPP-induced [3H]-5-HT release was neither sensitive to known nAChR antagonists nor dependent on external calcium. The differences between nicotinic agonist induced catecholamine and serotonin release suggest involvement of distinct nAChRs.

  10. Geochemical characterization of ground-water flow in the Santa Fe Group aquifer system, Middle Rio Grande Basin, New Mexico

    Science.gov (United States)

    Plummer, L. Niel; Bexfield, Laura M.; Anderholm, Scott K.; Sanford, Ward E.; Busenberg, Eurybiades

    2004-01-01

    Chemical and isotopic data were obtained from ground water and surface water throughout the Middle Rio Grande Basin (MRGB), New Mexico, and supplemented with selected data from the U.S. Geological Survey (USGS) National Water Information System (NWIS) and City of Albuquerque water-quality database in an effort to refine the conceptual model of ground-water flow in the basin. The ground-water data collected as part of this study include major- and minor-element chemistry (30 elements), oxygen-18 and deuterium content of water, carbon-13 content and carbon-14 activity of dissolved inorganic carbon, sulfur-34 content of dissolved sulfate, tritium, and dissolved atmospheric gases including nitrogen, argon, helium, chlorofluorocarbons,

  11. Fabrication and characterization of a rapid prototyped tissue engineering scaffold with embedded multicomponent matrix for controlled drug release

    DEFF Research Database (Denmark)

    Chen, Muwan; Le, Dang Q S; Hein, San

    2012-01-01

    Bone tissue engineering implants with sustained local drug delivery provide an opportunity for better postoperative care for bone tumor patients because these implants offer sustained drug release at the tumor site and reduce systemic side effects. A rapid prototyped macroporous polycaprolactone......, this scaffold can fulfill the requirements for both bone tissue engineering and local sustained release of an anticancer drug in vitro. These results suggest that the scaffold can be used clinically in reconstructive surgery after bone tumor resection. Moreover, by changing the composition and amount...... of individual components, the scaffold can find application in other tissue engineering areas that need local sustained release of drug....

  12. Comparing Titanium Release from Ceramic Tiles using a waste material characterization test - Influence of Calcium and Organic Matter concentrations

    DEFF Research Database (Denmark)

    Heggelund, Laura Roverskov; Hansen, Steffen Foss; Astrup, Thomas Fruergaard

    2015-01-01

    Nanomaterials are beneficial in the building industry to enhance or add certain features to commonly used materials. One example is the use of nano-titanium dioxide in the surface coating of ceramic tiles, to make the tiles surface self-cleaning. At the end of life stage, ceramic tiles might...... to assess if nano-titanium dioxide coated ceramic tiles are suitable for depositing in a landfill or not. Specifically, we used compliance batch test method, which is a simple test evaluating the release from a solid material to an aqueous media during 24 hrs. If nano-Ti particles are released from solid...... of the organic matter to fully cover the surface of the particles. We evaluated the titanium release from identical ceramic tiles - with and without a nano-titanium dioxide coating - and varied the concentrations of calcium chloride (100-500 mg/l) and humic acid (25-100 mg/l). The titanium release was quantified...

  13. Preparation and characterization of glycidyl methacrylate organo bridges grafted mesoporous silica SBA-15 as ibuprofen and mesalamine carrier for controlled release.

    Science.gov (United States)

    Rehman, Fozia; Rahim, Abdur; Airoldi, Claudio; Volpe, Pedro L O

    2016-02-01

    Mesoporous silica SBA-15 was synthesized and functionalized with bridged polysilsesquioxane monomers obtained by the reaction of 3-aminopropyltriethoxy silane with glycidyl methacrylate in 2:1 ratio. The synthesized mesoporous silica materials were characterized by elemental analysis, infrared spectroscopy, nuclear magnetic resonance spectroscopy, nitrogen adsorption, X-ray diffraction, thermogravimetry and scanning electron microscopy. The nuclear magnetic resonance in the solid state is in agreement with the sequence of carbon distributed in the attached organic chains, as expected for organically functionalized mesoporous silica. After functionalization with organic bridges the BET surface area was reduced from 1311.80 to 494.2m(2)g(-1) and pore volume was reduced from 1.98 to 0.89cm(3)g(-1), when compared to original precursor silica. Modification of the silica surface with organic bridges resulted in high loading capacity and controlled release of ibuprofen and mesalamine in biological fluids. The Korsmeyer-Peppas model better fits the release data indicating Fickian diffusion and zero order kinetics for synthesized mesoporous silica. The drug release rate from the modified silica was slow in simulated gastric fluid, (pH1.2) where less than 10% of mesalamine and ibuprofen were released in initial 8h, while comparatively high release rates were observed in simulated intestinal (pH6.8) and simulated body fluids (pH7.2). The preferential release of mesalamine at intestinal pH suggests that the modified silica could be a simple, efficient, inexpensive and convenient carrier for colon targeted drugs, such a mesalamine and also as a controlled drug release system.

  14. Partial purification and characterization of a peptide with growth hormone-releasing activity from extrapituitary tumors in patients with acromegaly.

    OpenAIRE

    Frohman, L A; Szabo, M; Berelowitz, M.; Stachura, M E

    1980-01-01

    Growth hormone (GH)-releasing activity has been detected in extracts of carcinoid and pancreatic islet tumors from three patients with GH-secreting pituitary tumors and acromegaly. Bioactivity was demonstrated in 2 N acetic acid extracts of the tumors using dispersed rat adenohypophyseal cells in primary monolayer culture and a rat anterior pituitary perifusion system. The GH-releasing effect was dose responsive and the greatest activity was present in the pancreatic islet tumor. Small amount...

  15. Characterization of lake water and ground water movement in the littoral zone of Williams Lake, a closed-basin lake in North central Minnesota

    Science.gov (United States)

    Schuster, P.F.; Reddy, M.M.; LaBaugh, J.W.; Parkhurst, R.S.; Rosenberry, D.O.; Winter, T.C.; Antweiler, R.C.; Dean, W.E.

    2003-01-01

    Williams Lake, Minnesota is a closed-basin lake that is a flow-through system with respect to ground water. Ground-water input represents half of the annual water input and most of the chemical input to the lake. Chemical budgets indicate that the lake is a sink for calcium, yet surficial sediments contain little calcium carbonate. Sediment pore-water samplers (peepers) were used to characterize solute fluxes at the lake-water-ground-water interface in the littoral zone and resolve the apparent disparity between the chemical budget and sediment data. Pore-water depth profiles of the stable isotopes ??18O and ??2H were non-linear where ground water seeped into the lake, with a sharp transition from lake-water values to ground-water values in the top 10 cm of sediment. These data indicate that advective inflow to the lake is the primary mechanism for solute flux from ground water. Linear interstitial velocities determined from ??2H profiles (316 to 528 cm/yr) were consistent with velocities determined independently from water budget data and sediment porosity (366 cm/yr). Stable isotope profiles were generally linear where water flowed out of the lake into ground water. However, calcium profiles were not linear in the same area and varied in response to input of calcium carbonate from the littoral zone and subsequent dissolution. The comparison of pore-water calcium profiles to pore-water stable isotope profiles indicate calcium is not conservative. Based on the previous understanding that 40-50 % of the calcium in Williams Lake is retained, the pore-water profiles indicate aquatic plants in the littoral zone are recycling the retained portion of calcium. The difference between the pore-water depth profiles of calcium and ??18O and ??2H demonstrate the importance of using stable isotopes to evaluate flow direction and source through the lake-water-ground-water interface and evaluate mechanisms controlling the chemical balance of lakes. Published in 2003 by John Wiley

  16. Preparation and characterization of 1-naphthylacetic acid-silica conjugated nanospheres for enhancement of controlled-release performance

    Science.gov (United States)

    Ao, Mingming; Zhu, Yuncong; He, Shun; Li, Deguang; Li, Pingliang; Li, Jianqiang; Cao, Yongsong

    2013-01-01

    Chemical pesticides have been widely used to increase the yield and quality of agricultural products as they are efficient, effective, and easy to apply. However, the rapid degradation and low utilization ratio of conventional pesticides has led to environmental pollution and resource waste. Nano-sized controlled-release formulations (CRFs) can provide better penetration through the plant cuticle and deliver the active ingredients efficiently to the targeted tissue. In this paper we reported novel conjugated nanospheres derived from 1-naphthylacetic acid (NNA), 3-aminopropyltriethoxysilane (APTES) and tetraethyl orthosilicate and their application as a controlled-release plant growth regulator. The NNA and APTES conjugate was prepared through a covalent cross-linking reaction and subsequent hydrolyzation and polycondensation to synthesize NNA-silica nanospheres. The release data indicated that the release of NNA was by non-Fickian transport and increased as particle size decreased. It was also found that the acidity-alkalinity was enhanced and as the temperature increased, the release of the active ingredient was faster. The nanoconjugate displayed a better efficacy in promoting root formation than NNA technical. The present study provides a novel synthesis route for CRFs comprising a pesticide, with long-duration sustained-release performance and good environmental compatibility. This method may be extended to other pesticides that possess a carboxyl group.

  17. Draft Technical Protocol for Characterizing Natural Attenuation of Chlorinated Solvent Ground-Water Plumes Discharging into Wetlands

    Science.gov (United States)

    2006-01-01

    others, 1984), and the distribution of marsh marigold (Caltha palustris L.) has been used to map seeps and springs next to a lake and in wetlands in...Minnesota (Rosenberry, 2000). Marsh marigold preferentially grows in ground-water discharge areas across the upper Midwest states and south central

  18. Near-Field Characterization of a Printed Circuit Board in the Presence of a Finite-sized Metallic Ground Plane

    DEFF Research Database (Denmark)

    Franek, Ondrej; Sørensen, Morten; Ebert, Hans

    2012-01-01

    Model of a generic printed circuit board (PCB) in a presence of a finite-sized metallic ground plane is introduced as a commonly occurring scenario of electronic module whose electromagnetic fields are disturbed by a nearby object. Finite-difference time-domain simulations are performed...

  19. Synthesis and Characterization of Sodium Alginate Conjugate and Study of Effect of Conjugation on Drug Release from Matrix Tablet.

    Science.gov (United States)

    Satheeshababu, B K; Mohamed, I

    2015-01-01

    The aim of the present research work to study the effect of conjugation of the polymer on drug release from the matrix tablets. Sodium alginate L-cysteine conjugate was achieved by covalent attachment of thiol group of L-cysteine with the primary amino group of sodium alginate through the amide bonds formed by primary amino groups of the sodium alginate and the carboxylic acid group of L-cysteine. The synthesised sodium alginate L-cysteine conjugate was characterised by determining of charring point, Fourier transmission-infrared and differential scanning calorimetric analysis. To study the effect of conjugation on drug release pattern, the matrix tablets were prepared using various proportions of sodium alginate and sodium alginate L-cysteine conjugate along with atorvastatin calcium as model drug. The wet granulation technique was adopted and prepared matrix tablets were evaluated for various physical parameters. The in vitro drug release study results suggested that tablet formulated in combination of sodium alginate and sodium alginate L-cysteine conjugate S4 showed 100% after 8 h drug release whereas formulated with only sodium alginate S0 released 40% in 8 h.

  20. Preparation and Characterization in vitro of Sustained-release Captopril/Chitosan-gelatin Net-polymer Microspheres(Cap/CGNPMs)

    Institute of Scientific and Technical Information of China (English)

    SONG Yimin; CHEN Xiguang; TANG Xuexi; LIU Chengshen; MENG Xianghong; YU Luojun

    2006-01-01

    The captopril/Chitosan-gelatin net-polymer microspheres (Cap/CGNPMs) were prepared using Chitosan(CS) and gelatin(Gel) by the methods of emulsification. A cross linked reagent alone or in combination with microcrystalline cellulose(MCC) was added in the process of preparation of microspheres to eliminate dose dumping and burst phenomenon of microspheres for the improvement of the therapeutic efficiency and the decrease of the side effects of captopril(Cap). The results indicate that Cap/CGNPMs have a spherical shape , smooth surface morphology and integral inside structure and no adhesive phenomena and good mobility,and the size distribution is mainly from 220 to 280 μm. Researches on the Cap release test in vitro demonstrate that Cap/CGNPMs are of the role of retarding release of Cap compared with Cap ordinary tablets (COT), embedding ratio (ER) ,drug loading (DL), and swelling ratio (SR), and release behaviors of CGNPMS are influenced by process conditions of preparation such as experimental material ratio (EMR) , composition of cross linking reagents. Among these factors , the EMR(1/4),CLR (FOR+TPP) and 0.75% microcrystalline cellulose (MCC) added to the microspheres are the optimal scheme to the preparation of Cap/CGNPMs. The Cap/CGNPMs have a good characteristic of sustained release of drug, and the process of emulsification and cross-linking process is simple and stable. The CGNPMs is probable to be one of an ideal sustained release system for water-soluble drugs.

  1. Use of chemical and isotopic tracers to characterize the interactions between ground water and surface water in mantled karst

    Science.gov (United States)

    Katz, B.G.; Coplen, T.B.; Bullen, T.D.; Hal, Davis J.

    1997-01-01

    In the mantled karst terrane of northern Florida, the water quality of the Upper Floridan aquifer is influenced by the degree of connectivity between the aquifer and the surface. Chemical and isotopic analyses [18O/16O (??18O), 2H/1H (??D), 13C/12C (??13C), tritium(3H), and strontium-87/strontium-86(87Sr/86Sr)]along with geochemical mass-balance modeling were used to identify the dominant hydrochemical processes that control the composition of ground water as it evolves downgradient in two systems. In one system, surface water enters the Upper Floridan aquifer through a sinkhole located in the Northern Highlands physiographic unit. In the other system, surface water enters the aquifer through a sinkhole lake (Lake Bradford) in the Woodville Karst Plain. Differences in the composition of water isotopes (??18O and ??D) in rainfall, ground water, and surface water were used to develop mixing models of surface water (leakage of water to the Upper Floridan aquifer from a sinkhole lake and a sinkhole) and ground water. Using mass-balance calculations, based on differences in ??18O and ??D, the proportion of lake water that mixed with meteoric water ranged from 7 to 86% in water from wells located in close proximity to Lake Bradford. In deeper parts of the Upper Floridan aquifer, water enriched in 18O and D from five of 12 sampled municipal wells indicated that recharge from a sinkhole (1 to 24%) and surface water with an evaporated isotopic signature (2 to 32%) was mixing with ground water. The solute isotopes, ??13C and 87Sr/86Sr, were used to test the sensitivity of binary and ternary mixing models, and to estimate the amount of mass transfer of carbon and other dissolved species in geochemical reactions. In ground water downgradient from Lake Bradford, the dominant processes controlling carbon cycling in ground water were dissolution of carbonate minerals, aerobic degradation of organic matter, and hydrolysis of silicate minerals. In the deeper parts of the Upper

  2. Dust aerosol characterization and transport features based on combined ground-based, satellite and model-simulated data

    Science.gov (United States)

    Vijayakumar, K.; Devara, P. C. S.; Rao, S. Vijaya Bhaskara; Jayasankar, C. K.

    2016-06-01

    In this paper, we study aerosol characteristics over an urban station in Western India, during a dust event that occurred between 19 and 26 March 2012, with the help of ground-based and satellite measurements and model simulation data. The aerosol parameters are found to change significantly during dust events and they suggest dominance of coarse mode aerosols. The fine mode fraction, size distribution and single scattering albedo reveal that dust (natural) aerosols dominate the anthropogenic aerosols over the study region. Ground-based measurements show drastic reduction in visibility on the dust-laden day (22 March 2012). Additionally, HYSPLIT model and satellite daily data have been used to trace the source, path and spatial extent of dust storm events. Most of the dust aerosols, during the study period, travel from west-to-east pathway from source-to-sink region. Furthermore, aerosol vertical profiles from CALIPSO and synoptic meteorological parameters from ECMWF re-analysis data reveal a layer of thick dust extending from surface to an altitude of about 4 km, and decrease in temperature and increase in specific humidity, respectively. The aerosol radiative forcing calculations indicate more cooling at the surface and warming in the atmosphere during dust event. The results of satellite observations are found to have good consistency with ground-based air quality measurements. Synthesis of satellite data integrated with ground-based observations, supplemented by model analysis, is found to be a promising technique for improved understanding of dust storm phenomenon and its impact on regional climate.

  3. Characterization of drug release and diffusion mechanism through hydroxyethylmethacrylate/methacrylic acid pH-sensitive hydrogel.

    Science.gov (United States)

    Varshosaz, Jaleh; Hajian, Mahmood

    2004-01-01

    Hydroxyethylmethacrylate/methacrylic acid copolymer cross-linked with ethylenglycol dimethacrylate was prepared by a bulk free radical polymerization method. The permeability studies of this pH-sensitive hydrogel to drugs with different water solubilities showed a water-content dependent diffusion or pore mechanism for ephedrine HCl (water-soluble model drug), whereas, a partition or solute-diffusion mechanism for indomethacin (a water-insoluble drug) was seen. Data analysis of release tests, according to the swelling interface number and Peppas equation for ephedrine HCl in pH 7.4, showed a biexponential model kinetic, whereas in pH 1.2 a swelling-controlled mechanism was seen. Indomethacin was released by an anomalous or non-Fickian release kinetics.

  4. Structural and oxidative stabilization of spray dried fish oil microencapsulates with gum arabic and sage polyphenols: Characterization and release kinetics.

    Science.gov (United States)

    Binsi, P K; Nayak, Natasha; Sarkar, P C; Jeyakumari, A; Muhamed Ashraf, P; Ninan, George; Ravishankar, C N

    2017-03-15

    The synergistic efficacy of gum arabic and sage polyphenols in stabilising capsule wall and protecting fish oil encapsulates from heat induced disruption and oxidative deterioration during spray drying was assessed. The emulsions prepared with sodium caseinate as wall polymer, gum arabic as wall co-polymer and sage extract as wall stabiliser was spray dried using a single fluid nozzle. Fish oil encapsulates stabilised with gum arabic and sage extract (SOE) exhibited significantly higher encapsulation efficiency compared to encapsulates containing gum arabic alone (FOE). Scanning electron microscopic and atomic force microscopic images revealed uniform encapsulates with good sphericity and smooth surface for SOE, compared to FOE powder. In vitro oil release of microencapsulates indicated negligible oil release in buffered saline whereas more than 80% of the oil loaded in encapsulates were released in simulated GI fluids. The encapsulates containing sage extract showed a lower rate of lipid oxidation during storage.

  5. Preparation, Characterization of Hydrophobic Drug in Combine Loaded Chitosan/Cyclodextrin/Trisodium Citrate Nanoparticles and in vitro Release Study

    Institute of Scientific and Technical Information of China (English)

    JI Jin-gou; ZHANG Jing-fen; HAO Shi-lei; WU Dan-jun; LIU Li; XU Yi

    2012-01-01

    Chitosan/cyclodextrin/trisodium citrate(CS/CD/TSC) nanoparticles with ibuprofen(IBU) loaded were prepared via the ionic cross-linking method,with trisodium citrate selected as the cross-linking agent.The drug-loading capacity,particle size,zeta potential and surface morphology of the obtained nanoparticles were investigated.The results show a good drug-loading capacity.The prepared nanoparticles were spherical in shape with an average size of 293.7 nm and a zeta potential of +30.72 mV.The in vitro release studies show that the controlled release of IBU from the nanoparticles was followed.The drug release from CS/β-CD/TSC nanoparticles followed non-Fickian or anomalous diffusion.

  6. Characterization of a poly(ether urethane)-based controlled release membrane system for delivery of ketoprofen

    Science.gov (United States)

    Macocinschi, Doina; Filip, Daniela; Vlad, Stelian; Oprea, Ana Maria; Gafitanu, Carmen Anatolia

    2012-10-01

    A poly(ether urethane) based on polytetrahydrofuran containing hydroxypropyl cellulose for biomedical applications was tested for its biocompatibility. Ketoprofen was incorporated (3% and 6%) in the polyurethane matrix as an anti-inflammatory drug. Kinetic and drug release mechanisms were studied. The pore size and pore size distribution of the polyurethane membranes were investigated by scanning electron microscopy. Surface tension characteristics as well as moisture sorption properties such as diffusion coefficients and equilibrium moisture contents of the membrane material were studied. It was found that kinetics and release mechanisms are in function of medium pH, composition of polymer-drug system, pore morphology and pore size distribution. Prolonged nature of release of ketoprofen is assured by low amount of drug in polyurethane membrane and physiological pH.

  7. Fabrication and characterization of a rapid prototyped tissue engineering scaffold with embedded multicomponent matrix for controlled drug release

    Directory of Open Access Journals (Sweden)

    Chen M

    2012-08-01

    Full Text Available Muwan Chen,1,2 Dang QS Le,1,2 San Hein,2 Pengcheng Li,1 Jens V Nygaard,2 Moustapha Kassem,3 Jørgen Kjems,2 Flemming Besenbacher,2 Cody Bünger11Orthopaedic Research Lab, Aarhus University Hospital, Aarhus C, Denmark; 2Interdisciplinary Nanoscience Center (iNANO, Aarhus University, Aarhus C, Denmark; 3Department of Endocrinology and Metabolism, Odense University Hospital, Odense C, DenmarkAbstract: Bone tissue engineering implants with sustained local drug delivery provide an opportunity for better postoperative care for bone tumor patients because these implants offer sustained drug release at the tumor site and reduce systemic side effects. A rapid prototyped macroporous polycaprolactone scaffold was embedded with a porous matrix composed of chitosan, nanoclay, and β-tricalcium phosphate by freeze-drying. This composite scaffold was evaluated on its ability to deliver an anthracycline antibiotic and to promote formation of mineralized matrix in vitro. Scanning electronic microscopy, confocal imaging, and DNA quantification confirmed that immortalized human bone marrow-derived mesenchymal stem cells (hMSC-TERT cultured in the scaffold showed high cell viability and growth, and good cell infiltration to the pores of the scaffold. Alkaline phosphatase activity and osteocalcin staining showed that the scaffold was osteoinductive. The drug-release kinetics was investigated by loading doxorubicin into the scaffold. The scaffolds comprising nanoclay released up to 45% of the drug for up to 2 months, while the scaffold without nanoclay released 95% of the drug within 4 days. Therefore, this scaffold can fulfill the requirements for both bone tissue engineering and local sustained release of an anticancer drug in vitro. These results suggest that the scaffold can be used clinically in reconstructive surgery after bone tumor resection. Moreover, by changing the composition and amount of individual components, the scaffold can find application in other

  8. Ground Vehicle Robotics Presentation

    Science.gov (United States)

    2012-08-14

    Mr. Jim Parker Associate Director Ground Vehicle Robotics Distribution Statement A. Approved for public release Report Documentation Page...Briefing 3. DATES COVERED 01-07-2012 to 01-08-2012 4. TITLE AND SUBTITLE Ground Vehicle Robotics Presentation 5a. CONTRACT NUMBER 5b. GRANT...ABSTRACT Provide Transition-Ready, Cost-Effective, and Innovative Robotics and Control System Solutions for Manned, Optionally-Manned, and Unmanned

  9. Synthesis and Characterization of Chemically Cross-Linked Acrylic Acid/Gelatin Hydrogels: Effect of pH and Composition on Swelling and Drug Release

    Directory of Open Access Journals (Sweden)

    Syed Majid Hanif Bukhari

    2015-01-01

    Full Text Available This present work was aimed at synthesizing pH-sensitive cross-linked AA/Gelatin hydrogels by free radical polymerization. Ammonium persulfate and ethylene glycol dimethacrylate (EGDMA were used as initiator and as cross-linking agent, respectively. Different feed ratios of acrylic acid, gelatin, and EGDMA were used to investigate the effect of monomer, polymer, and degree of cross-linking on swelling and release pattern of the model drug. The swelling behavior of the hydrogel samples was studied in 0.05 M USP phosphate buffer solutions of various pH values pH 1.2, pH 5.5, pH 6.5, and pH 7.5. The prepared samples were evaluated for porosity and sol-gel fraction analysis. Pheniramine maleate used for allergy treatment was loaded as model drug in selected samples. The release study of the drug was investigated in 0.05 M USP phosphate buffer of varying pH values (1.2, 5.5, and 7.5 for 12 hrs. The release data was fitted to various kinetic models to study the release mechanism. Hydrogels were characterized by Fourier transformed infrared (FTIR spectroscopy which confirmed formation of structure. Surface morphology of unloaded and loaded samples was studied by surface electron microscopy (SEM, which confirmed the distribution of model drug in the gel network.

  10. Characterization and superficial transformations on mini-matrices made of interpolymer complexes of chitosan and carboxymethylcellulose during in vitro clarithromycin release.

    Science.gov (United States)

    Gómez-Burgaz, Marta; Torrado, Guillermo; Torrado, Santiago

    2009-09-01

    Different interpolymer complexes (IPCs) of chitosan (CS) and carboxymethylcellulose sodium salt (CMC) were used to elaborate mini-matrices containing clarithromycin (CAM). IPCs were characterized by FTIR, DSC and powder X-ray (XRD). Compression processes did not modify the physical state of CAM which was in its polymorph Form II. However, during tableting, polymer/polymer interactions occurred to form matrix systems that were confirmed by DSC. When mini-matrices were placed in acetate buffer (pH 4.2), the formation of a CAM solvate was determined by XRD, FTIR and DSC, showing the presence of incorporated crystallizing solvent molecules. Grazing incidence X-ray diffraction (GID) enabled us to profile transformations of CAM on surfaces of mini-matrices when it is in intimate contact with dissolution medium, and its conversion to a solvate form prior to its dissolution process. Besides, FTIR and DSC revealed polymer-polymer electrostatic interactions during dissolution process. Furthermore, swelling and eroding studies and in vitro drug release exhibited that when increasing the amount of CS within IPCs, swelling and erosion rates were greater and CAM release was faster. Zero-order kinetics from drug release profiles were related to linear erosion kinetics, and highlighted that erosion played an important role in drug release due to CAM poor solubility at this pH.

  11. Characterization of temperature and pH-responsive poly-N-isopropylacrylamide-co-polymer nanoparticles for the release of antimicrobials

    Science.gov (United States)

    Hill, Laura E.; Gomes, Carmen L.

    2014-09-01

    Chitosan and alginate are both pH-responsive biopolymers extracted from crustacean exoskeletons and brown algae, respectively. Poly-N-isopropylacrylamide (PNIPAAM) is a hydrogel that becomes hydrophobic at a lower-critical solution temperature. This study sought to combine pH- and temperature-responsive polymers via crosslinking, in order to create a dual-stimuli responsive polymer for hydrophobic antimicrobial compounds delivery, improving their antimicrobial effects. Cinnamon bark extract (CBE) was used as a model for hydrophobic antimicrobial. Two co-polymers were synthesized to create two nanoparticles types: chitosan-co-PNIPAAM and alginate-co-PNIPAAM. Nanoparticles were formed from the resulting co-polymers using a self-assembly top-down process followed by glutaraldehyde or calcium chloride crosslinking. These nanoparticles were then used as controlled delivery vehicles for CBE, whose rapid release could be triggered by specific external stimuli. For the same pH and temperature conditions, the chitosan-co-PNIPAAM nanoparticles were significantly more potent bacterial inhibitors against both pathogens and also exhibited a faster CBE release over time as well as slightly higher entrapment efficiency. The alginate-co-PNIPAAM nanoparticles were significantly smaller and exhibited a slow, gradual release over a long time period. Although both nanoparticles were able to effectively inhibit pathogen growth at lower (P < 0.05) concentration than free CBE, the chitosan-co-PNIPAAM nanoparticles were more effective in delivering a natural antimicrobial with controlled release against foodborne pathogens.

  12. Characterization of a poly(ether urethane)-based controlled release membrane system for delivery of ketoprofen

    Energy Technology Data Exchange (ETDEWEB)

    Macocinschi, Doina, E-mail: eradro2002@yahoo.com [Department of Physical Chemistry of Polymers, ' Petru Poni' Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41 A, 700487 Iasi (Romania); Filip, Daniela; Vlad, Stelian; Oprea, Ana Maria [Department of Physical Chemistry of Polymers, ' Petru Poni' Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41 A, 700487 Iasi (Romania); Gafitanu, Carmen Anatolia [Faculty of Pharmacy, ' Gr. T. Popa' University of Medicine and Pharmacy, Universitatii 16, 700115 Iasi (Romania)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Ketoprofen incorporation in poly(ether urethane) microporous membrane. Black-Right-Pointing-Pointer Moisture sorption properties of as-cast membrane. Black-Right-Pointing-Pointer Drug release mechanisms in function of pH and composition of membranes. - Abstract: A poly(ether urethane) based on polytetrahydrofuran containing hydroxypropyl cellulose for biomedical applications was tested for its biocompatibility. Ketoprofen was incorporated (3% and 6%) in the polyurethane matrix as an anti-inflammatory drug. Kinetic and drug release mechanisms were studied. The pore size and pore size distribution of the polyurethane membranes were investigated by scanning electron microscopy. Surface tension characteristics as well as moisture sorption properties such as diffusion coefficients and equilibrium moisture contents of the membrane material were studied. It was found that kinetics and release mechanisms are in function of medium pH, composition of polymer-drug system, pore morphology and pore size distribution. Prolonged nature of release of ketoprofen is assured by low amount of drug in polyurethane membrane and physiological pH.

  13. Biopharmaceutical characterization of oral controlled/modified-release drug products. In vitro/in vivo correlation of roxatidine.

    Science.gov (United States)

    Frick, A; Möller, H; Wirbitzki, E

    1998-11-01

    From the marketed drug product Roxane(R) 75 mg C/MR capsules (roxatidine controlled/modified-release capsules), an in vitro/in vivo comparison was performed to demonstrate a 1:1 correlation between in vitro and in vivo dissolution, and, furthermore, to ensure bioequivalence of the roxatidine controlled/modified-release (C/MR) capsules exhibiting dissolution profiles within the defined acceptance criteria. This 1:1 in vitro/in vivo comparison was calculated using a model independent numerical deconvolution method. The high degree of correlation is extremely rare, nevertheless it allows to omit the testing of clinical side batches for the setting of acceptance criteria for the in vitro dissolution of roxatidine controlled/modified-release (C/MR) capsules. The 1:1 in vitro/in vivo correlation can be explained by the biopharmaceutical characteristics of the drug substance as well as the drug product, that is, pH-independent high solubility of the drug substance as well as dissolution which is independent of pH and agitation. These facts lead to a controlled/modified-release formulation. Therefore, it is important to keep in mind that in most cases in which a pH-dependent solubility/dissolution as well as permeability characteristics can be found, a 1:1 in vitro/in vivo correlation could not be expected.

  14. PREPARATION, CHARACTERIZATION, AND PHARMACEUTICAL APPLICATION OF LINEAR DEXTRIN .3. DRUG-RELEASE FROM FATTY SUPPOSITORY BASES CONTAINING AMYLODEXTRIN

    NARCIS (Netherlands)

    TEWIERIK, GHP; EISSENS, AC; LERK, CF

    Drug release from fatty suppository bases containing a solid dispersion of diazepam with amylodextrin or a complex of prednisolone with amylodextrin was analyzed in a flow-through model. Being present as a suspension in the fatty base, particles of complex or solid dispersion are transported to the

  15. Characterization of Atmospheric Aerosol Behavior and Climatic Effects by Analysis of SAGE 2 and Other Space, Air, and Ground Measurements

    Science.gov (United States)

    Livingston, John M.

    1999-01-01

    This report documents the research performed under NASA Ames Cooperative Agreement NCC 2-991, which covered the period 1 April 1997 through 31 March 1999. Previously, an interim technical report (Technical Report No. 1, 20 March 1998) summarized the work completed during the period 1 April 1997 through 31 March 1998. The objective of the proposed research was to advance our understanding of atmospheric aerosol behavior, aerosol-induced climatic effects, and the remote measurement and retrieval capabilities of spaceborne sensors such as SAGE II by combining and comparing data from these instruments and from airborne and ground-based instruments.

  16. Synthesis and characterization of homopolymers bearing acid-cleavable cationic side-chains for pH-modulated release of DNA.

    Science.gov (United States)

    Xu, Zhangyan; Lai, Junping; Tang, Rupei; Ji, Weihang; Wang, Rui; Wang, Jun; Wang, Chun

    2014-07-01

    A new type of homopolymers, PMAOE, bearing acid-cleavable cationic side-chains is synthesized and characterized. PMAOE is obtained via free radical polymerization, and they could efficiently bind and condense plasmid DNA at neutral pH. The strength of DNA binding is dependent on the length of PMAOE chains. NMR analysis reveals that hydrolysis of the ortho ester group of PMAOE follows an exocyclic mechanism and the rate of hydrolysis is much accelerated at mildly acidic pH, leading to accelerated disruption of polyplexes and release of DNA in mildly acidic environment. PMAOE is not toxic to cultured NIH 3T3 and COS-7 cells measured by MTT. This study demonstrates a unique mechanism of achieving pH-modulated binding and release of DNA from polymers with potential applications for gene delivery.

  17. Characterization of Personal Privacy Devices (PPD) radiation pattern impact on the ground and airborne segments of the local area augmentation system (LAAS) at GPS L1 frequency

    Science.gov (United States)

    Alkhateeb, Abualkair M. Khair

    Personal Privacy Devices (PPDs) are radio-frequency transmitters that intentionally transmit in a frequency band used by other devices for the intent purpose of denying service to those devices. These devices have shown the potential to interfere with the ground and air sub-systems of the Local Area Augmentation Systems (LAAS), a GPS-based navigation aids at commercial airports. The Federal Aviation Administration (FAA) is concerned by the potential impact of these devices to GPS navigation aids at airports and has commenced an activity to determine the severity of this threat. In support of this situation, the research in this dissertation has been conducted under (FAA) Cooperative Agreement 2011-G-012, to investigate the impact of these devices on the LAAS. In order to investigate the impact of PPDs Radio Frequency Interference (RFI) on the ground and air sub-systems of the LAAS, the work presented in phase one of this research is intended to characterize the vehicle's impact on the PPD's Effective Isotropic Radiated Power (EIRP). A study was conceived in this research to characterize PPD performance by examining the on-vehicle radiation patterns as a function of vehicle type, jammer type, jammer location inside a vehicle and jammer orientation at each location. Phase two was to characterize the GPS Radiation Pattern on Multipath Limiting Antenna. MLA has to meet stringent requirements for acceptable signal detection and multipath rejection. The ARL-2100 is the most recent MLA antenna proposed to be used in the LAAS ground segment. The ground-based antenna's radiation pattern was modeled. This was achieved via (HFSS) a commercial-off the shelf CAD-based modeling code with a full-wave electromagnetic software simulation package that uses the Finite Element Analysis. Phase three of this work has been conducted to study the characteristics of the GPS Radiation Pattern on Commercial Aircraft. The airborne GPS antenna was modeled and the resulting radiation pattern on

  18. Lipid nanoparticles for topical and transdermal application for alopecia treatment: development, physicochemical characterization, and in vitro release and penetration studies

    DEFF Research Database (Denmark)

    Gomes, M. J.; Martins, S.; Ferreira, D.

    2014-01-01

    less than 30% was achieved for minoxidil nanoparticles, over 28 days. Controlled release assays in physiological conditions demonstrated that nanoparticles loaded with minoxidil yielded a prolonged release, as desired. Penetration assays through pig ear skin demonstrated that nanoparticles loaded...... and finasteride) into the dermis and hair follicles. Lipid nanoparticles, prepared by ultrasonication method, showed mean particle sizes around 200 nm, which is sufficient for reaching the dermis and hair follicles, and zeta potential values around -30 mV, which indicates good physical stability. Over 28 days...... of storage, no significant variations in these parameters were observed, which indicates that all nanoformulations are stable in storage over that period. Cryo-scanning electron microscope measurements showed that all the lipid nanoparticles exhibited a spherical shape and a smooth surface regardless...

  19. Genetic characterization of natural variants of Vpu from HIV-1 infected individuals from Northern India and their impact on virus release and cell death.

    Directory of Open Access Journals (Sweden)

    Sachin Verma

    Full Text Available BACKGROUND: Genetic studies reveal that vpu is one of the most variable regions in HIV-1 genome. Functional studies have been carried out mostly with Vpu derived from laboratory adapted subtype B pNL 4-3 virus. The rationale of this study was to characterize genetic variations that are present in the vpu gene from HIV-1 infected individuals from North-India (Punjab/Haryana and determine their functional relevance. METHODS: Functionally intact vpu gene variants were PCR amplified from genomic DNA of HIV-1 infected individuals. These variants were then subjected to genetic analysis and unique representative variants were cloned under CMV promoter containing expression vector as well as into pNL 4-3 HIV-1 virus for intracellular expression studies. These variants were characterized with respect to their ability to promote virus release as well as cell death. RESULTS: Based on phylogenetic analysis and extensive polymorphisms with respect to consensus Vpu B and C, we were able to arbitrarily assign variants into two major groups (B and C. The group B variants always showed significantly higher virus release activity and exhibited moderate levels of cell death. On the other hand, group C variants displayed lower virus release activity but greater cell death potential. Interestingly, Vpu variants with a natural S61A mutation showed greater intracellular stability. These variants also exhibited significant reduction in their intracellular ubiquitination and caused greater virus release. Another group C variant that possessed a non-functional β-TrcP binding motif due to two critical serine residues (S52 and S56 being substituted with isoleucine residues, showed reduced virus release activity but modest cytotoxic activity. CONCLUSIONS: The natural variations exhibited by our Vpu variants involve extensive polymorphism characterized by substitution and deletions that contribute toward positive selection. We identified two major groups and an extremely

  20. ACETYLATION AND CHARACTERIZATION OF ENSET STARCH AND EVALUATION OF ITS DIRECT COMPRESSION AND DRUG RELEASE SUSTAINING PROPERTIES

    Directory of Open Access Journals (Sweden)

    Efrem Nigussu, Anteneh Belete and Tsige Gebre-Mariam*

    2013-11-01

    Full Text Available Enset (Ensete ventricosum, Musaceae, a plant widely cultivated in south and southwest of Ethiopia, has been shown to be a rich source of starch. In an effort to produce directly compressible matrix-forming excipient, native enset starch was acetylated. Starch acetates (SA with degrees of substitution (DS of 0.672 and 2.142 were evaluated. Fourier transform infrared (FTIR spectra of the modified starches verified the acetylation of the starch molecules. Further investigations revealed that acetylation increased swelling power and solubility, improved flow property and compactability of the starch. The tensile strength of SA matrix tablets increased with an increase in DS. Plain tablets of SA with DS 0.672 disintegrated within 3 min while those of SA with DS 2.142 did not disintegrate over a period of 2 h. Dissolution studies of theophylline loaded SA tablets conducted in 0.1 N HCl for the first 1.5 h and in phosphate buffer pH 6.8 for the remaining study time revealed the change in drug release rate from rapid to sustained release (>12 h as the DS increased from 0.672 to 2.142. The dissolution data obtained best fitted Higuchi model with R2 > 0.99. The drug release diffusional exponent (n, obtained from Korsemeyer-Peppas model, varied between 0.4899 - 0.6369 for different theophylline/SA ratios and the goodness of the fit was > 0.99 in each case which indicated the deviation from Fickian diffusion. Accordingly, high degree of acetylation renders enset starch highly compressible and suitable for sustained release formulations that makes it amenable for use as an alternative pharmaceutical excipient.

  1. A Rat Model of Full Thickness Thermal Injury Characterized by Thermal Hyperalgesia, Mechanical Allodynia, Pronociceptive Peptide Release and Tramadol Analgesia

    Science.gov (United States)

    2014-01-01

    hyperalgesia, mechanical allodynia, pronociceptive peptide release and tramadol analgesia 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...therapeutic tramadol combines opioid receptor activation and 5HT/NE reuptake inhibition [9 11]. Both preclinical and clinical research has reported that... tramadol reduces acute, postoperative, neuropathic and cancer pain [9,10,12 14] and may have a lower propensity to induce addiction [15] with little to

  2. Evaluating fluorescence spectroscopy as a tool to characterize cyanobacteria intracellular organic matter upon simulated release and oxidation in natural water.

    Science.gov (United States)

    Korak, Julie A; Wert, Eric C; Rosario-Ortiz, Fernando L

    2015-01-01

    Intracellular organic matter (IOM) from cyanobacteria may be released into natural waters following cell death in aquatic ecosystems and during oxidation processes in drinking water treatment plants. Fluorescence spectroscopy was evaluated to identify the presence of IOM from three cyanobacteria species during simulated release into natural water and following oxidation processes (i.e. ozone, free chlorine, chloramine, chlorine dioxide). Peak picking and the fluorescence index (FI) were explored to determine which IOM components (e.g., pigments) provide unique and persistent fluorescence signatures with minimal interferences from the background dissolved organic matter (DOM) found in Colorado River water (CRW). When IOM was added to ultrapure water, the fluorescence signature of the three cyanobacteria species showed similarities to each other. Each IOM exhibited a strong protein-like fluorescence and fluorescence at Ex 370 nm and Em 460 nm (FDOM), where commercial fluorescence sensors monitor. All species also had strong phycobiliprotein fluorescence (i.e. phycocyanin or phycoerythrin) in the higher excitation range (500-650 nm). All three IOM isolates had FI values greater than 2. When IOM was added to CRW, phycobiliprotein fluorescence was quenched through interactions between IOM and CRW-DOM. Mixing IOM and CRW demonstrated that protein-like and FDOM intensity responses were not a simple superposition of the starting material intensities, indicating that interactions between IOM and CRW-DOM fluorescing moieties were important. Fluorescence intensity in all regions decreased with exposure to ozone, free chlorine, and chlorine dioxide, but the FI still indicated compositional differences compared to CRW-DOM. The phycobiliproteins in IOM are not promising as a surrogate for IOM release, because their fluorescence intensity is quenched by interactions with DOM and decreased during oxidation processes. Increases in both FDOM intensity and FI are viable qualitative

  3. Simultaneous loading of 5-florouracil and SPIONs in HSA nanoparticles: Optimization of preparation, characterization and in vitro drug release study

    Directory of Open Access Journals (Sweden)

    H. Kouchakzadeh

    2016-01-01

    Full Text Available Objective(s: Over the past two decades, considerable interest has been focused on utilizing biocompatible magnetic nanoparticles (MNPs for biomedical applications. In this study, production of human serum albumin (HSA nanoparticles using desolvation technique that were simultaneous loaded with high amounts of superparamagnetic iron oxide nanoparticles (SPIONs and 5-flourouracil (5-FU was investigated. Materials and Methods: 5-FU loading (% and SPIONs entrapment efficiency (% were optimized using response surface methodology (RSM. The design expert software used to analyse the interactive effects of pH, 5-FU and SPIONs concentrations. Results:The optimum conditions found to be pH of 8.2, drug concentration of 1.5 mg/ml and SPIONs concentration of 2.79 mg/ml. Under the mentioned optimum conditions, particles with the size of 111.8 nm, zeta potential of -37.1 mV, 5-FU loading of 15.8% and SPIONs entrapment efficiency of 41.1% were obtained. In vitro cumulative release of 5-FU from the nanoparticles was evaluated in phosphate buffer saline (pH 7.4, 37 °C. Results indicated that 85% of the 5-FU released during 95 h, which revealed a sustained release profile. In addition, Vibrating Sample Magnetometer (VSM analyses confirmed the superparamagnetic properties of magnetic albumin nanoparticles manufactured under the optimum conditions. Conclusion: According to the findings,SPIONs and 5-FU loaded HAS  nanoparticles arepromising for use as  novel targeted delivery system due to proper magnetic and drug release behaviours.

  4. Preparation and characterization of chitosan/genipin/poly(N-vinyl-2-pyrrolidone) films for controlled release drugs

    Energy Technology Data Exchange (ETDEWEB)

    Aldana, Ana Agustina, E-mail: aaldana@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina); Gonzalez, Agustin, E-mail: agustingonzalez@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina); Strumia, Miriam C., E-mail: mcs@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina); Martinelli, Marisa, E-mail: mmartinelli@fcq.unc.edu.ar [Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba (UNC), Edificio de Ciencias II, Medina Allende y Haya de la Torre, Ciudad Universitaria, Cordoba 5000 (Argentina)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Cross-linked chitosan films using genipin and/or PVP. Black-Right-Pointing-Pointer Propranolol hydrochloride was used like a model drug to release studies. Black-Right-Pointing-Pointer Incorporating PVP improves mechanical and diffusion properties. Black-Right-Pointing-Pointer Ch-Gen 0.10% and Ch-Gen 0.10%-PVP have optimal behavior. - Abstract: The study of the physicochemical and functional properties of chitosan films cross-linked with genipin and poly(N-vinyl-2-pyrrolidone) (PVP) was performed in this work. Cross-linked films were prepared by casting method from acetic acid solutions. The structure and physical properties of the films were analyzed by infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy ({sup 13}C NMR), differential scanning calorimetry (DSC) and mechanical testings. Propranolol hydrochloride was used like a model drug to determine the behavior of drug release from films. The drug release capacity was measured and compared with the degree of cross-linking, mechanical properties and swelling index. There was an appropriate balance of hydrophilicity, mechanical properties and diffusion by the incorporation of PVP into the networks cross-linked with genipin. The combination of both cross-linkers allows obtaining a soft and tough material potentially applicable as a controlled release. This research represents the first report where both cross-linkers, chemical and ionic agents, are used for obtaining films. These studies suggest that the chitosan films prepared here are promising drug delivery systems for buccal application, with thermal stability and acceptable mechanical properties. Buccal films may be preferred in terms of flexibility and comfort.

  5. Release mechanism and kinetic exchange for phosphorus (P) in lake sediment characterized by diffusive gradients in thin films (DGT).

    Science.gov (United States)

    Wu, Zhihao; Wang, Shengrui

    2017-06-05

    Diffusive gradients in thin films (DGT) technique has been newly designed for the identification of formation mechanisms of "internal phosphorus (P)-loading" and the numerical simulation of P exchange at DGT/sediment interface in Lake Dianchi. The primary mechanism was Fe-redox controlled P release from Fe-bound P in sediments, which was revealed by CDGT (P and Fe), total P (Fe) and P (Fe) fractions in NH4Cl and BD phases in sediments and their relationships at sites (N-T). The breakdown of algae biomass in the top layer of sediments at sites (O-T) and the coupled P/Fe/sulfur reactions at two depths at site N played a minor role in P release. The "internal P-loading" was calculated to be 19.23ta(-1), which was 3.0% of the "entering P-loading". At sites (1-9), DGT induced flux in sediments (DIFS) model for P was used to derive curves (i) the resupply parameter (R) against deployment time and (ii) the dissolved/sorbed concentrations against the distance at DGT/sediment interface, the variation characters of which were controlled by kinetics and sediment-P pool. Sulfide microniches in sediments related to P release were evaluated by computer imaging densitometry (CID). DGT-DIFS-CID should be a reliable method to reveal P mobilization in lake sediments.

  6. Characterization of Raoultella planticola Rs-2 microcapsule prepared with a blend of alginate and starch and its release behavior.

    Science.gov (United States)

    Wu, Zhansheng; He, Yanhui; Chen, Lijun; Han, Yajie; Li, Chun

    2014-09-22

    To judiciously use Raoultella planticola Rs-2 and develop its biodegradable and controlled-release formulations, Rs-2 was encapsulated with various combinations of sodium alginate (NaAlg) and starch. Sodium alginate, soluble starch, and CaCl2 showed good biocompatibility with Rs-2 for preparing microcapsules. These microcapsules were spherical in shape and their particle size, embedding rate, swelling ratio of Rs-2 microcapsules and release numbers of viable Rs-2 cells increased with the increasing of starch and NaAlg concentrations. Meanwhile, the biodegradability of the microcapsules constantly increases when the wt% of starch increased, but decreased when the amount of NaAlg increased. In addition, the release mechanism of microcapsules was consistent with that of the Ritger-Peppas model, which involves the Case II diffusion mechanism. In summary, the desired properties of the microcapsules can be modulated by varying the starch and alginate amounts of capsule materials. This process has broad application prospects to meet the needs of agricultural production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. High-amylose sodium carboxymethyl starch matrices: development and characterization of tramadol hydrochloride sustained-release tablets for oral administration.

    Science.gov (United States)

    Nabais, Teresa; Leclair, Grégoire

    2014-01-01

    Substituted amylose (SA) polymers were produced from high-amylose corn starch by etherification of its hydroxyl groups with chloroacetate. Amorphous high-amylose sodium carboxymethyl starch (HASCA), the resulting SA polymer, was spray-dried to obtain an excipient (SD HASCA) with optimal binding and sustained-release (SR) properties. Tablets containing different percentages of SD HASCA and tramadol hydrochloride were produced by direct compression and evaluated for dissolution. Once-daily and twice-daily SD HASCA tablets containing two common dosages of tramadol hydrochloride (100 mg and 200 mg), a freely water-soluble drug, were successfully developed. These SR formulations presented high crushing forces, which facilitate further tablet processing and handling. When exposed to both a pH gradient simulating the pH variations through the gastrointestinal tract and a 40% ethanol medium, a very rigid gel formed progressively at the surface of the tablets providing controlled drug-release properties. These properties indicated that SD HASCA was a promising and robust excipient for oral, sustained drug-release, which may possibly minimize the likelihood of dose dumping and consequent adverse effects, even in the case of coadministration with alcohol.

  8. Novel multilayer microcapsules based on soy protein isolate fibrils and high methoxyl pectin: Production, characterization and release modeling.

    Science.gov (United States)

    Ansarifar, Elham; Mohebbi, Mohebbat; Shahidi, Fakhri; Koocheki, Arash; Ramezanian, Navid

    2017-04-01

    In this study, novel microcapsules were produced through the layer by layer adsorption of food-grade and plant-based polyelectrolytes, soy protein isolate (SPI) fibrils and high methoxyl pectin (HMP). The physical properties of the fibrils were investigated by TEM and AFM and the properties of the microcapsules such as size, uniformity, zeta potential, morphology, functional groups, modeling and the release kinetics of limonene were examined. The results revealed that SPI-fibrils had a thickness varying from 1 to 10nm and strand like structure. SEM images showed that the microcapsules were spherical and the thickness increased by the number of layers which led to the improvement of shell strength. The FTIR results confirmed that HMP and SPI-fibrils were adsorbed layer by layer as the walls of microcapsules and presence of limonene was stable into microcapsules. By increasing the number of layers of the shell from 2 to 6, the release rate of limonene decreased significantly. The index n in Rigter-Peppas model indicates that the release mechanism of limonene from multilayer microcapsules followed a non-Fick law. This method of microcapsule production is very simple and could be readily industrialized, especially for the manufacture of food products for vegetarians. Copyright © 2017. Published by Elsevier B.V.

  9. Characterization of the release profile of doxycycline by PLGA microspheres adjunct to non-surgical periodontal therapy.

    Science.gov (United States)

    Moura, Lucas Alves; Ribeiro, Fernanda Vieira; Aiello, Talita Bianchi; Duek, Eliana Ap De Rezende; Sallum, Enilson Antonio; Nociti Junior, Francisco Humberto; Casati, Márcio Zaffalon; Sallum, Antonio Wilson

    2015-01-01

    The aim of this pilot study was to assess the release of locally delivered doxycycline by poly (l-lactide-co-glycolide) (PLGA) microspheres in the periodontal pocket of patients with chronic periodontitis, treated by non-surgical periodontal therapy. Nineteen sites of non-adjacent teeth of four different patients were evaluated. Five milligram of PLGA microspheres loaded with 16 doxycycline hyclate (DOX) was administered per periodontal site. To quantify DOX released into the periodontal pocket, gingival crevicular fluid (GCF) was collected from the sites on days 2, 5, 7, 10, 15, and 20 after DOX application, and high-performance liquid chromatography was performed. Data were statistically assessed by ANOVA/Tukey test. At days 2, 5, and 7, the DOX concentration was stably sustained (23.33 ± 1.38, 23.4 ± 1.82, and 22.75 ± 1.33 μg/mL, respectively), with no significant differences over these assessment times (p > 0.05). At days 10 and 15, a tendency was observed toward a decrease in DOX concentration (21.74 ± 0.91 and 20.53 ± 4.88 μg/mL, respectively), but a significant decrease in GCF drug concentration (19.69 ± 4.70 μg/mL) was observed only on day 20. The DOX delivery system developed demonstrated a successful sustained release after local administration, as an adjunct to non-surgical periodontal therapy.

  10. Cyclodextrin-crosslinked poly(acrylic acid): Synthesis, physicochemical characterization and controlled release of diflunisal and fluconazole from hydrogels.

    Science.gov (United States)

    Kutyła, Marguerite J; Lambert, Lynette K; Davies, Nigel M; McGeary, Ross P; Shaw, P Nicholas; Ross, Benjamin P

    2013-02-28

    The aim of this work was to develop mucoadhesive hydrogels with variable drug delivery properties by crosslinking poly(acrylic acid) (PAA) with cyclodextrins (CDs). CD-PAA polymers with high CD content and good inter-batch reproducibility were synthesized by activating PAA with SOCl2, then reacting PAA chloride with CD in the presence of 4-dimethylaminopyridine at 50°C. Manipulation of the synthesis conditions affected the physicochemical character of the CD-PAA polymers and hydrogels in terms of CD content, the average number of ester bonds to an individual CD, viscosity, and the association and release of model drugs. Inclusion complexation of diflunisal (DIF) and fluconazole (FLZ) with CD-PAA hydrogels was assessed by (19)F NMR spectroscopy and association constants (Kas) for DIF were in the range 220-486M(-1) with βCD-PAA and 1327-6055M(-1) with hydroxypropyl-βCD-PAA. For FLZ the Ka range was 34-171M(-1) with hydroxypropyl-βCD-PAA. The hydrogels were found to release both drugs by means of Fickian diffusion as the predominant mechanism. A slight trend toward negative correlation was found between the Ka and Higuchi kH values for DIF. These results highlight the potential of CD-PAA hydrogels to control the release of model drugs through inclusion complexation.

  11. Synthesis of nanocomposite 2-methyl-4-chlorophenoxyacetic acid with layered double hydroxide: physicochemical characterization and controlled release properties

    Energy Technology Data Exchange (ETDEWEB)

    Sarijo, Siti Halimah, E-mail: izaddinizaddin@yahoo.com; Ghazali, Sheikh Ahmad Izaddin Sheikh Mohd [Faculty of Applied Sciences, Universiti Teknologi MARA (Malaysia); Hussein, Mohd Zobir [Universiti Putra Malaysia, Department of Chemistry, Faculty of Science (Malaysia); Sidek, Norizzah Jaafar [Faculty of Applied Sciences, Universiti Teknologi MARA (Malaysia)

    2013-01-15

    A new organic-inorganic hybrid nanocomposite Zn-Al-MCPA-layered double hydroxide (ZAM) was prepared by intercalation of 2-methyl-4-chlorophenoxyacetic acid (MCPA) into Zn-Al-layered double hydroxide (ZAL) at various concentration of MCPA ranging from 0.1 to 0.7 M. The pH of the synthesis was kept constant at 7.5. Well-ordered hybrid nanocomposite was obtained with 0.4 M MCPA with an expansion of basal spacing from 8.9 Angstrom-Sign in the ZAL to 19.7 Angstrom-Sign in the resulting nanocomposite. The FTIR spectra of the nanocomposite show resemblance peaks of the MCPA and Zn-Al-layered double hydroxide indicating the inclusion of MCPA into the layered double hydroxide. The average particle size of ZAL and ZAM in this study was 115 and 128 nm, respectively. Percentage loading of MCPA was found to be 45.0 % (w/w), calculated based on the percentage of carbon in the sample. The release of MCPA into various aqueous solution was found to be dependent to the anion in the aqueous solution in the order of phosphate > sulfate > chloride with the percentage release of 80, 44, and 8%, respectively. This study shows that Zn-Al-layered double hydroxide can be used as a host carrier for herbicide, MCPA, with controlled release capability.

  12. Synthesis of nanocomposite 2-methyl-4-chlorophenoxyacetic acid with layered double hydroxide: physicochemical characterization and controlled release properties

    Science.gov (United States)

    Sarijo, Siti Halimah; Ghazali, Sheikh Ahmad Izaddin Sheikh Mohd; Hussein, Mohd Zobir; Sidek, Norizzah Jaafar

    2013-01-01

    A new organic-inorganic hybrid nanocomposite Zn-Al-MCPA-layered double hydroxide (ZAM) was prepared by intercalation of 2-methyl-4-chlorophenoxyacetic acid (MCPA) into Zn-Al-layered double hydroxide (ZAL) at various concentration of MCPA ranging from 0.1 to 0.7 M. The pH of the synthesis was kept constant at 7.5. Well-ordered hybrid nanocomposite was obtained with 0.4 M MCPA with an expansion of basal spacing from 8.9 Å in the ZAL to 19.7 Å in the resulting nanocomposite. The FTIR spectra of the nanocomposite show resemblance peaks of the MCPA and Zn-Al-layered double hydroxide indicating the inclusion of MCPA into the layered double hydroxide. The average particle size of ZAL and ZAM in this study was 115 and 128 nm, respectively. Percentage loading of MCPA was found to be 45.0 % (w/w), calculated based on the percentage of carbon in the sample. The release of MCPA into various aqueous solution was found to be dependent to the anion in the aqueous solution in the order of phosphate > sulfate > chloride with the percentage release of 80, 44, and 8 %, respectively. This study shows that Zn-Al-layered double hydroxide can be used as a host carrier for herbicide, MCPA, with controlled release capability.

  13. Characterization of earthquake-induced ground motion from the L'Aquila seismic sequence of 2009, Italy

    Science.gov (United States)

    Malagnini, Luca; Akinci, Aybige; Mayeda, Kevin; Munafo', Irene; Herrmann, Robert B.; Mercuri, Alessia

    2011-01-01

    Based only on weak-motion data, we carried out a combined study on region-specific source scaling and crustal attenuation in the Central Apennines (Italy). Our goal was to obtain a reappraisal of the existing predictive relationships for the ground motion, and to test them against the strong-motion data [peak ground acceleration (PGA), peak ground velocity (PGV) and spectral acceleration (SA)] gathered during the Mw 6.15 L'Aquila earthquake (2009 April 6, 01:32 UTC). The L'Aquila main shock was not part of the predictive study, and the validation test was an extrapolation to one magnitude unit above the largest earthquake of the calibration data set. The regional attenuation was determined through a set of regressions on a data set of 12 777 high-quality, high-gain waveforms with excellent S/N ratios (4259 vertical and 8518 horizontal time histories). Seismograms were selected from the recordings of 170 foreshocks and aftershocks of the sequence (the complete set of all earthquakes with ML≥ 3.0, from 2008 October 1 to 2010 May 10). All waveforms were downloaded from the ISIDe web page (), a web site maintained by the Istituto Nazionale di Geofisica e Vulcanologia (INGV). Weak-motion data were used to obtain a moment tensor solution, as well as a coda-based moment-rate source spectrum, for each one of the 170 events of the L'Aquila sequence (2.8 ≤Mw≤ 6.15). Source spectra were used to verify the good agreement with the source scaling of the Colfiorito seismic sequence of 1997-1998 recently described by Malagnini (2008). Finally, results on source excitation and crustal attenuation were used to produce the absolute site terms for the 23 stations located within ˜80 km of the epicentral area. The complete set of spectral corrections (crustal attenuation and absolute site effects) was used to implement a fast and accurate tool for the automatic computation of moment magnitudes in the Central Apennines.

  14. Characterization of depolarization-coupled release of glutamate from cultured mouse cerebellar granule cells using DL-threo-beta-benzyloxyaspartate (DL-TBOA) to distinguish between the vesicular and cytoplasmic pools

    DEFF Research Database (Denmark)

    Bak, Lasse K; Schousboe, Arne; Waagepetersen, Helle S

    2003-01-01

    Release of preloaded [3H]D-aspartate in response to depolarization induced by N-methyl-D-aspartate (NMDA) or the endogenous agonist glutamate was characterized using cultured glutamatergic cerebellar granule neurons. Release from the vesicular and the cytoplasmic glutamate pools, respectively, wa...

  15. Characterization and in vitro and in vivo evaluation of cross-linked chitosan films as implant for controlled release of citalopram

    Indian Academy of Sciences (India)

    Patit P Kundu; Santosh Kumar Jindal; Manish Goswami

    2013-02-01

    The aim of the present study is to develop cross-linked chitosan (CH) films that can release drug over an extended period of time and that too in a controlled manner. A solution of different percentages of CH, is prepared in 1% lactic acid, followed by addition of citalopram (CTP) and then reacted with increasing amounts of glutaraldehyde (GL) to obtain films with different cross-linking densities. Prepared films are characterized for their physical and mechanical properties. The films are then subjected to in vitro drug release studies using pH 7.4 phosphate buffer saline (PBS) as dissolution medium and cumulative amount of drug released is calculated. Kinetic analysis of drug release is performed using Power law model and Higuchi’s model.With increase in concentration of CH, water absorption capacity and mechanical strength are increased; whereas, water vapour permeability and elasticity of the films are decreased. The effect of cross-linking agent, GL, is such that with an increase in the amount of GL, water vapour permeability, water absorption capacity and elasticity of the films are decreased; whereas, mechanical strength increased to some extent and then decreased. In vitro release studies indicate that films containing 3% CH, cross-linked with 2–3% GL and films containing 4%CH, cross-linked 1%GL are able to sustain the drug release for a prolonged time along with releasing almost complete drug in a desired period. Out of these batches, films containing 3% CH, cross-linked with 2–3% GL are having sufficient strength, water vapour permeation, water absorption capacity and elongation at break for implantation purpose. The in vitro degradation studies and histopathological studies were carried out with a sample film (batch C3 as in table 1) in rabbit model. In vitro degradation study indicates that the films maintained their integrity for desired implantation. The histopathological studies under optical microscope indicates that on implanting, there is no

  16. Towards improved characterization of northern wetlands (or other landscapes) by remote sensing - a rapid approach to collect ground truth data

    Science.gov (United States)

    Gålfalk, Magnus; Karlson, Martin; Crill, Patrick; Bastviken, David

    2017-04-01

    The calibration and validation of remote sensing land cover products is highly dependent on accurate ground truth data, which are costly and practically challenging to collect. This study evaluates a novel and efficient alternative to field surveys and UAV imaging commonly applied for this task. The method consists of i) a light weight, water proof, remote controlled RGB-camera mounted on an extendable monopod used for acquiring wide-field images of the ground from a height of 4.5 meters, and ii) a script for semi-automatic image classification. In the post-processing, the wide-field images are corrected for optical distortion and geometrically rectified so that the spatial resolution is the same over the surface area used for classification. The script distinguishes land surface components by color, brightness and spatial variability. The method was evaluated in wetland areas located around Abisko, northern Sweden. Proportional estimates of the six main surface components in the wetlands (wet and dry Sphagnum, shrub, grass, water, rock) were derived for 200 images, equivalent to 10 × 10 m field plots. These photo plots were then used as calibration data for a regional scale satellite based classification which separates the six wetland surface components using a Sentinel-1 time series. The method presented in this study is accurate, rapid, robust and cost efficient in comparison to field surveys (time consuming) and drone mapping (which require low wind speeds and no rain, suffer from battery limited flight times, have potential GPS/compass errors far north, and in some areas are prohibited by law).

  17. Methods for characterizing fine particulate matter using ground observations and remotely sensed data: potential use for environmental public health surveillance.

    Science.gov (United States)

    Al-Hamdan, Mohammad Z; Crosson, William L; Limaye, Ashutosh S; Rickman, Douglas L; Quattrochi, Dale A; Estes, Maurice G; Qualters, Judith R; Sinclair, Amber H; Tolsma, Dennis D; Adeniyi, Kafayat A; Niskar, Amanda Sue

    2009-07-01

    This study describes and demonstrates different techniques for surface fitting daily environmental hazards data of particulate matter with aerodynamic diameter less than or equal to 2.5 microm (PM2.5) for the purpose of integrating respiratory health and environmental data for the Centers for Disease Control and Prevention (CDC) pilot study of Health and Environment Linked for Information Exchange (HELIX)-Atlanta. It presents a methodology for estimating daily spatial surfaces of ground-level PM2.5 concentrations using the B-Spline and inverse distance weighting (IDW) surface-fitting techniques, leveraging National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectrometer (MODIS) data to complement U.S. Environmental Protection Agency (EPA) ground observation data. The study used measurements of ambient PM2.5 from the EPA database for the year 2003 as well as PM2.5 estimates derived from NASA's satellite data. Hazard data have been processed to derive the surrogate PM2.5 exposure estimates. This paper shows that merging MODIS remote sensing data with surface observations of PM,2. not only provides a more complete daily representation of PM,2. than either dataset alone would allow, but it also reduces the errors in the PM2.5-estimated surfaces. The results of this study also show that although the IDW technique can introduce some numerical artifacts that could be due to its interpolating nature, which assumes that the maxima and minima can occur only at the observation points, the daily IDW PM2.5 surfaces had smaller errors in general, with respect to observations, than those of the B-Spline surfaces. Finally, the methods discussed in this paper establish a foundation for environmental public health linkage and association studies for which determining the concentrations of an environmental hazard such as PM2.5 with high accuracy is critical.

  18. Preliminary report on the stable isotope imaging and characterization of surface and ground water resources in the southern Sacramento Valley

    Energy Technology Data Exchange (ETDEWEB)

    Davisson, M.L. [Lawrence Livermore National Lab., CA (United States); Criss, R.E.; Campbell, K.R. [California Univ., Davis, CA (United States). Dept. of Geology

    1993-11-01

    This document contains information about the water resources in Sacramento. The project considers isotopic characterization of groundwater and the environmental effects of the misuse of water resources. In particular, the study looks at the effects extensive agriculture and the overdrafting of groundwater.

  19. Linking ground observations, simulation model output, and remote sensing data to characterize phenology across diverse arid landscapes

    Science.gov (United States)

    We combined long-term data on plant phenology with simulation modeling output and remote sensing data to characterize diverse landscapes at the Jornada Experimental Range in the northern Chihuahuan Desert of southern New Mexico. Phenology of 15 key species in Chihuahuan Desert plant communities have...

  20. Section 11: Surface Water Pathway - Likelihood of Release

    Science.gov (United States)

    Surface water releases can include the threat to targets from overland flow of hazardous substances and from flooding or the threat from the release of hazardous substances to ground water and the subsequent discharge of contaminated ground w

  1. Poly(3-hydroxybutyrate)/metribuzin formulations: characterization, controlled release properties, herbicidal activity, and effect on soil microorganisms.

    Science.gov (United States)

    Volova, Tatiana; Zhila, Natalia; Kiselev, Evgeniy; Prudnikova, Svetlana; Vinogradova, Olga; Nikolaeva, Elena; Shumilova, Anna; Shershneva, Anna; Shishatskaya, Ekaterina

    2016-12-01

    Slow-release formulations of the herbicide metribuzin (MET) embedded in the polymer matrix of degradable poly-3-hydroxybutyrate [P(3HB)] in the form of microparticles, films, microgranules, and pellets were developed and tested. The kinetics of polymer degradation, MET release, and accumulation in soil were studied in laboratory soil microecosystems with higher plants. The study shows that MET release can be controlled by using different techniques of constructing formulations and by varying MET loading. MET accumulation in soil occurs gradually, as the polymer is degraded. The average P(3HB) degradation rates were determined by the geometry of the formulation, reaching 0.17, 0.12, 0.04, and 0.05 mg/day after 60 days for microparticles, films, microgranules, and pellets, respectively. The herbicidal activities of P(3HB)/MET formulations and commercial formulation Sencor Ultra were tested on the Agrostis stolonifera and Setaria macrocheata plants. The parameters used to evaluate the herbicidal activity were plant density and the weight of fresh green biomass measured at days 10, 20, and 30 after sowing. All P(3HB)/MET formulations had pronounced herbicidal activity, which varied depending on MET loading and the stage of the experiment. In the early phases of the experiment, the herbicidal effect of P(3HB)/MET formulations with the lowest MET loading (10 %) was comparable with that of the commercial formulation. The herbicidal effect of P(3HB)/MET formulations with higher MET loadings (25 and 50 %) at later stages of the experiment were stronger than the effect of Sencor Ultra.

  2. Nanoscale Diblock copolymer micelles: characterizations and estimation of the effective diffusion coefficients of biomolecules release through cylindrical diffusion model.

    Directory of Open Access Journals (Sweden)

    M Wahab Amjad

    Full Text Available Biomolecules have been widely investigated as potential therapeutics for various diseases. However their use is limited due to rapid degradation and poor cellular uptake in vitro and in vivo. To address this issue, we synthesized a new nano-carrier system comprising of cholic acid-polyethylenimine (CA-PEI copolymer micelles, via carbodiimide-mediated coupling for the efficient delivery of small interfering ribonucleic acid (siRNA and bovine serum albumin (BSA as model protein. The mean particle size of siRNA- or BSA-loaded CA-PEI micelles ranged from 100-150 nm, with zeta potentials of +3-+11 mV, respectively. Atomic force, transmission electron and field emission scanning electron microscopy demonstrated that the micelles exhibited excellent spherical morphology. No significant morphology or size changes were observed in the CA-PEI micelles after siRNA and BSA loading. CA-PEI micelles exhibited sustained release profile, the effective diffusion coefficients were successfully estimated using a mathematically-derived cylindrical diffusion model and the release data of siRNA and BSA closely fitted into this model. High siRNA and BSA binding and loading efficiencies (95% and 70%, respectively were observed for CA-PEI micelles. Stability studies demonstrated that siRNA and BSA integrity was maintained after loading and release. The CA-PEI micelles were non cytotoxic to V79 and DLD-1 cells, as shown by alamarBlue and LIVE/DEAD cell viability assays. RT-PCR study revealed that siRNA-loaded CA-PEI micelles suppressed the mRNA for ABCB1 gene. These results revealed the promising potential of CA-PEI micelles as a stable, safe, and versatile nano-carrier for siRNA and the model protein delivery.

  3. Biomolecular characterization of exosomes released from cancer stem cells: Possible implications for biomarker and treatment of cancer.

    Science.gov (United States)

    Kumar, Dhruv; Gupta, Dwijendra; Shankar, Sharmila; Srivastava, Rakesh K

    2015-02-20

    Cancer recognized as one of the leading irrepressible health issues is contributing to increasing mortality-rate day-by-day. The tumor microenvironment is an important field of cancer to understand the detection, treatment and prevention of cancer. Recently, cancer stem cell (CSC) research has shown promising results aiming towards cancer diagnostics and treatment. Here, we found that prostate and breast cancer stem cells secreted vesicles of endosomal origin, called exosomes showed strong connection between autophagy and exosomes released from CSCs. Exosomes may serve as vesicles to communicate with neoplastic cells (autocrine and paracrine manner) and normal cells (paracrine and endocrine manner) and thereby suppress immune systems and regulate neoplastic growth, and metastasis. They can also be used as biomarkers for various cancers. We detected tetraspanin proteins (CD9, CD63, CD81), Alix and tumor susceptibility gene-101 (TSG101) of exosomal markers from rotenone treated CSCs. We have also detected the induction of autophagy genes, Atg7 and conversion of autophagy marker (LC3-I to LC3-II), and tetraspanin proteins (CD9, CD63, CD81) in rotenone treated CSCs by western blotting. The mRNA expression of CD9, CD63, CD81 and TSG101 analyzed by qRT-PCR showed that the rotenone induced the expression of CD9, CD63, CD81 and TSG101 in CSCs. Electron microscopy of rotenone treated CSCs showed the mitochondrial damage of CSCs as confirmed by the release of exosomes from CSCs. The constituents of exosomes may be useful to understand the mechanism of exosomes formation, release and function, and also serve as a useful biomarker and provide novel therapeutic strategies for the treatment and prevention of cancer.

  4. Synthesis and Characterization of Sodium Alginate Conjugate and Study of Effect of Conjugation on Drug Release from Matrix Tablet

    OpenAIRE

    Satheeshababu, B. K.; Mohamed, I.

    2015-01-01

    The aim of the present research work to study the effect of conjugation of the polymer on drug release from the matrix tablets. Sodium alginate L-cysteine conjugate was achieved by covalent attachment of thiol group of L-cysteine with the primary amino group of sodium alginate through the amide bonds formed by primary amino groups of the sodium alginate and the carboxylic acid group of L-cysteine. The synthesised sodium alginate L-cysteine conjugate was characterised by determining of charrin...

  5. Novel pH-sensitive interpenetrating network hydrogel beads of carboxymethylcellulose-(polyacrylamide-grafted-alginate) for controlled release of ketoprofen: preparation and characterization.

    Science.gov (United States)

    Kulkarni, Raghavendra V; Sa, Biswanath

    2008-10-01

    Novel pH-sensitive carboxymethylcellulose-(polyacrylamide-grafted-sodium alginate) interpenetrating network (IPN) hydrogel beads loaded with ketoprofen were prepared using ionotropic gelation and covalent crosslinking method. Polyacrylamide-grafted-sodium alginate (PAAm-g-SA) copolymer was synthesized by free radical polymerization using ammonium persulfate (APS) as free radical initiator under the nitrogen atmosphere followed by hydrolysis using sodium hydroxide. The grafting, alkaline hydrolysis and crosslinking reactions were confirmed by Fourier transform infrared spectroscopy (FTIR). Beads were characterized by differential scanning calorimetric (DSC) analysis, thermogravimetric analysis (TGA), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The mechanical properties of the prepared IPNs were investigated. The erosion was observed with the beads containing only ionic crosslinks whereas it was negligible with the beads containing both ionic and covalent crosslinks. The swelling of the beads and drug release was significantly increased when pH of the medium was changed from acidic to alkaline (P<0.05). The swelling and release data were fitted to an empirical equation to determine the transport mechanism. Drug release followed case II transport mechanism in acidic medium whereas anomalous/non-Fickian transport mechanism was observed in alkaline medium.

  6. Preparation and characterization of oxidized starch/poly(N,N-dimethylaminoethyl methacrylate) semi-IPN cryogels and in vitro controlled release evaluation of indomethacin.

    Science.gov (United States)

    Apopei Loghin, Diana Felicia; Biliuta, Gabriela; Coseri, Sergiu; Dragan, Ecaterina Stela

    2017-03-01

    Fabrication of novel semi-interpenetrating polymer network (semi-IPN) cryogels by cross-linking polymerization of N,N-dimethylaminoethyl methacrylate (DMAEM) in the presence of either oxidized potato starch (OPS) or oxidized wheat starch (OWS) and their characterization are presented in the paper. The influence of the nature of entrapped polymer on the properties of the composite cryogels was evaluated by the swelling kinetics, FT-IR spectroscopy, scanning electron microscopy, and response at external stimuli such as temperature, pH, and ionic strength. Indomethacin (IDM), taken as a model anti-inflammatory drug, was easily loaded into the composite cryogels by the solvent sorption-evaporation strategy. The in vitro release of IDM from the semi-IPN cryogels was low in simulated gastric fluid at pH 1.3, irrespective of the nature of the entrapped oxidized starch, and consistent in simulated intestinal fluid (SIF) at pH 7.4, the influence of the entrapped polysaccharide being evident. The release mechanism of IDM from the composite cryogels was discussed based on two kinetic models, finding that the drug release at 37°C was pseudo-Fickian diffusion, regardless the cryogel composition. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Preparation and characterization of chitosan-Polyethylene glycol-polyvinylpyrrolidone-coated superparamagnetic iron oxide nanoparticles as carrier system: Drug loading and in vitro drug release study.

    Science.gov (United States)

    Prabha, G; Raj, V

    2016-05-01

    In the present research work, the anticancer drug "curcumin" is loaded with Chitosan (CS)-polyethylene glycol (PEG)-polyvinylpyrrolidone (PVP) (CS-PEG-PVP) polymer nanocomposites coated with superparamagnetic iron oxide (Fe3 O4 ) nanoparticles. The system can be used for targeted and controlled drug delivery of anticancer drugs with reduced side effects and greater efficiency. The prepared nanoparticles were characterized by Fourier transmission infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Curcumin drug-loaded Fe3 O4 -CS, Fe3 O4 -CS- PEG and Fe3 O4 -CS-PEG-PVP nanoparticles exhibited the mean particle size in the range of 183 - 390 nm with a zeta potential value of 26 mV-41 mV as measured using Malvern Zetasizer. The encapsulation efficiency, loading capacity and in-vitro drug release behaviour of curcumin drug-loaded Fe3 O4 -CS, Fe3 O4 -CS-PEG, and Fe3 O4 -CS-PEG-PVP nanoparticles were studied using UV spectrophotometer. Besides, the cytotoxicity of the prepared nanoparticles using MTT assay was also studied. The curcumin drug release was examined at different pH medium (4.5 and 7.4) and temperature (37°C and 45°C), and it was proved that the drug release depends upon the pH medium and temperature in addition to the nature of matrix.

  8. Beyond platinum: synthesis, characterization, and in vitro toxicity of Cu(II-releasing polymer nanoparticles for potential use as a drug delivery vector

    Directory of Open Access Journals (Sweden)

    Harris Alesha

    2011-01-01

    Full Text Available Abstract The field of drug delivery focuses primarily on delivering small organic molecules or DNA/RNA as therapeutics and has largely ignored the potential for delivering catalytically active transition metal ions and complexes. The delivery of a variety of transition metals has potential for inducing apoptosis in targeted cells. The chief aims of this work were the development of a suitable delivery vector for a prototypical transition metal, Cu2+, and demonstration of the ability to impact cancer cell viability via exposure to such a Cu-loaded vector. Carboxylate-functionalized nanoparticles were synthesized by free radical polymerization and were subsequently loaded with Cu2+ via binding to particle-bound carboxylate functional groups. Cu loading and release were characterized via ICP MS, EDX, XPS, and elemental analysis. Results demonstrated that Cu could be loaded in high weight percent (up to 16 wt.% and that Cu was released from the particles in a pH-dependent manner. Metal release was a function of both pH and the presence of competing ligands. The toxicity of the particles was measured in HeLa cells where reductions in cell viability greater than 95% were observed at high Cu loading. The combined pH sensitivity and significant toxicity make this copper delivery vector an excellent candidate for the targeted killing of disease cells when combined with an effective cellular targeting strategy.

  9. Beyond platinum: synthesis, characterization, and in vitro toxicity of Cu(II)-releasing polymer nanoparticles for potential use as a drug delivery vector

    Science.gov (United States)

    Harris, Alesha N.; Hinojosa, Barbara R.; Chavious, Montaleé D.; Petros, Robby A.

    2011-07-01

    The field of drug delivery focuses primarily on delivering small organic molecules or DNA/RNA as therapeutics and has largely ignored the potential for delivering catalytically active transition metal ions and complexes. The delivery of a variety of transition metals has potential for inducing apoptosis in targeted cells. The chief aims of this work were the development of a suitable delivery vector for a prototypical transition metal, Cu2+, and demonstration of the ability to impact cancer cell viability via exposure to such a Cu-loaded vector. Carboxylate-functionalized nanoparticles were synthesized by free radical polymerization and were subsequently loaded with Cu2+ via binding to particle-bound carboxylate functional groups. Cu loading and release were characterized via ICP MS, EDX, XPS, and elemental analysis. Results demonstrated that Cu could be loaded in high weight percent (up to 16 wt.%) and that Cu was released from the particles in a pH-dependent manner. Metal release was a function of both pH and the presence of competing ligands. The toxicity of the particles was measured in HeLa cells where reductions in cell viability greater than 95% were observed at high Cu loading. The combined pH sensitivity and significant toxicity make this copper delivery vector an excellent candidate for the targeted killing of disease cells when combined with an effective cellular targeting strategy.

  10. Preparation and characterization of nimesulide loaded poly (methyl methacrylate/poly (ethylene oxide blend microspheres: In vitro release studies

    Directory of Open Access Journals (Sweden)

    K Sudhakar

    2013-01-01

    Full Text Available Poly (methyl methacrylate/poly (ethylene oxide (PMMA/PEO blend microspheres were prepared by solvent evaporation technique using poly (vinyl alcohol (PVA as a stabilizer. Nimesulide, an arthritis drug was successfully loaded into these microspheres. The effect of experimental variables such as ratio of ploy (methyl methacrylate to poly (ethylene oxide on nimesulide encapsulation efficiency, release rate, size, and morphology of the microspheres has been investigated. Nimesulide loaded microspheres were analyzed using Fourier transform infrared (FTIR, differential scanning calorimetry (DSC, X-ray diffraction (X-RD, and scanning electron micrograph (SEM. FTIR spectroscopy was used to explain the blending of polymers. DSC and X-RD techniques were used to investigate the crystalline nature of the drug after encapsulation. DSC and X-RD results indicated a nonuniform dispersion of nimesulide in the PMMA/PEO blend matrix. SEMs indicated the formation of spherical microspheres with distinct size. Nimesulide was successfully encapsulated up to 85% in the polymeric matrices. In vitro dissolution experiments performed in pH 7.4 buffer medium indicated a controlled release of nimesulide from blend microspheres up to 12 h.

  11. Development and characterization of PLGA nanocapsules of grandisin isolated from Virola surinamensis: in vitro release and cytotoxicity studies

    Directory of Open Access Journals (Sweden)

    Luciano Aparecido Stecanella

    2013-02-01

    Full Text Available The most studied phyto constituent isolated from Virola surinamensis (Rol. ex Rottb. Warb., Myristicaceae, is the tetrahydrofuran neolignan grandisin, which exhibits a series of biological activities, including trypanocidal, larvicidal and antitumoral. Due to its extremely low solubility, additional studies, including in vivo investigations are challenged by the difficulties in the development of an effective drug delivery system for grandisin. The encapsulation in polymeric nanoparticles is a very attractive alternative for overcoming some of these limitations. In this work, PLGA nanocapsules loaded with grandisin were developed in an attempt to optimize the efficacy of grandisin as an antitumoral drug, with high drug loading and efficiency, prolonged drug release and increased physical-chemical stability. Mean diameter of the nanocapsules was lower than 200 nm, with very low polydispersity. Encapsulation efficiency was above 90%. A sustained in vitro drug release was achieved for up to twenty days and cytotoxicity was markedly increased (IC50 for grandisin-NC and grandisin were 0.005 µM and 0.078 µM, respectively, indicating that polymeric nanocapsules are a potential drug delivery system for grandisin allowing the preparation of formulations viable for further in vivo studies.

  12. Development and characterization of PLGA nanocapsules of grandisin isolated from Virola surinamensis: in vitro release and cytotoxicity studies

    Directory of Open Access Journals (Sweden)

    Luciano Aparecido Stecanella

    2012-01-01

    Full Text Available The most studied phyto constituent isolated from Virola surinamensis (Rol. ex Rottb. Warb., Myristicaceae, is the tetrahydrofuran neolignan grandisin, which exhibits a series of biological activities, including trypanocidal, larvicidal and antitumoral. Due to its extremely low solubility, additional studies, including in vivo investigations are challenged by the difficulties in the development of an effective drug delivery system for grandisin. The encapsulation in polymeric nanoparticles is a very attractive alternative for overcoming some of these limitations. In this work, PLGA nanocapsules loaded with grandisin were developed in an attempt to optimize the efficacy of grandisin as an antitumoral drug, with high drug loading and efficiency, prolonged drug release and increased physical-chemical stability. Mean diameter of the nanocapsules was lower than 200 nm, with very low polydispersity. Encapsulation efficiency was above 90%. A sustained in vitro drug release was achieved for up to twenty days and cytotoxicity was markedly increased (IC50 for grandisin-NC and grandisin were 0.005 µM and 0.078 µM, respectively, indicating that polymeric nanocapsules are a potential drug delivery system for grandisin allowing the preparation of formulations viable for further in vivo studies.

  13. Synthesis, characterization and in vitro drug release of cisplatin loaded Cassava starch acetate–PEG/gelatin nanocomposites

    Directory of Open Access Journals (Sweden)

    V. Raj

    2016-10-01

    Full Text Available The aim of the present study is to examine the feasibility of Cassava starch acetate (CSA–polyethylene glycol (PEG–gelatin (G nanocomposites as controlled drug delivery systems. It is one of the novel drug vehicles which can be used for the controlled release of an anticancer drug. Simple nano precipitation method was used to prepare the carriers CSA–PEG–G nanocomposites and they were used for entrapping cisplatin (CDDP. Through FT-IR spectroscopy, the linking among various components of the system was proved and with the help of scanning electron microscope and transmission electron microscopy (TEM, the surface morphology was investigated. The particle sizes of the CSA–CDDP, CSA–CDDP–PEG and CSA–CDDP–PEG–G polymer composites were between 140 and 350 nm, as determined by a Zetasizer. Drug encapsulation efficiency, drug loading capacity and in vitro release of CDDP were evaluated respectively. The findings revealed that the cross linked CSA–PEG–G nanocomposites can be a potential polymeric carrier for controlled delivery of CDDP.

  14. Potential of Ground Penetrating Radar for the characterization of the shallow water table in the Mnasra region in Morocco

    Directory of Open Access Journals (Sweden)

    Imane SEBARI

    2016-03-01

    Full Text Available Morocco is a water-scarce country confronted with a severe dependence on rain-fed agriculture and dwindling groundwater reserves. Since 1995, new water regulation laws and management strategies have been promulgated providing a comprehensive framework for an integrated management. Moreover, water managers should have precise data on the current state of water tables depth in strategic aquifers. Unfortunately, the main source of these data are sporadic wells with no automated monitoring systems making the assessment of water table dynamics, costly, time consuming and out-phased with decision maker needs. In this respect, this paper focuses on the capability of Ground Penetrating Radar to determine the depth of shallow water table in Mnasra region, located in the Gharb region of Morocco as a pilot study to generalize its use in the future for groundwater dynamic monitoring purposes in Morocco. The experiment was undertaken using Mala 800 MHz shielded antennas and was able to probe the depth of the upper fresh water table at 3.75 m deep in the Mnasra aquifer in semi-arid conditions. Data collected by GPR can be used as substitute for well logs to enhance the monitoring of water tables in stressed areas during droughts and excessive recharges during rainy season.

  15. Characterization of Optically and Electrically Evoked Dopamine Release in Striatal Slices from Digenic Knock-in Mice with DAT-Driven Expression of Channelrhodopsin

    Science.gov (United States)

    2017-01-01

    Fast-scan cyclic voltammetry (FCV) is an established method to monitor increases in extracellular dopamine (DA) concentration ([DA]o) in the striatum, which is densely innervated by DA axons. Ex vivo brain slice preparations provide an opportunity to identify endogenous modulators of DA release. For these experiments, local electrical stimulation is often used to elicit release of DA, as well as other transmitters, in the striatal microcircuitry; changes in evoked increases in [DA]o after application of a pharmacological agent (e.g., a receptor antagonist) indicate a regulatory role for the transmitter system interrogated. Optogenetic methods that allow specific stimulation of DA axons provide a complementary, bottom-up approach for elucidating factors that regulate DA release. To this end, we have characterized DA release evoked by local electrical and optical stimulation in striatal slices from mice that genetically express a variant of channelrhodopsin-2 (ChR2). Evoked increases in [DA]o in the dorsal and ventral striatum (dStr and vStr) were examined in a cross of a Cre-dependent ChR2 line (“Ai32” mice) with a DAT::Cre mouse line. In dStr, repeated optical pulse-train stimulation at the same recording site resulted in rundown of evoked [DA]o using heterozygous mice, which contrasted with the stability seen with electrical stimulation. Similar rundown was seen in the presence of a nicotinic acetylcholine receptor (nAChR) antagonist, implicating the absence of concurrent nAChR activation in DA release instability in slices. Rundown with optical stimulation in dStr could be circumvented by recording from a population of sites, each stimulated only once. Same-site rundown was less pronounced with single-pulse stimulation, and a stable baseline could be attained. In vStr, stable optically evoked increases in [DA]o at single sites could be achieved using heterozygous mice, although with relatively low peak [DA]o. Low release could be overcome by using mice with a

  16. A stent for co-delivering paclitaxel and nitric oxide from abluminal and luminal surfaces: Preparation, surface characterization, and in vitro drug release studies

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Annemarie; Mani, Gopinath, E-mail: Gopinath.Mani@usd.edu

    2013-08-15

    Most drug-eluting stents currently available are coated with anti-proliferative drugs on both abluminal (toward blood vessel wall) and luminal (toward lumen) surfaces to prevent neointimal hyperplasia. While the abluminal delivery of anti-proliferative drugs is useful for controlling neointimal hyperplasia, the luminal delivery of such drugs impairs or prevents endothelialization which causes late stent thrombosis. This research is focused on developing a bidirectional dual drug-eluting stent to co-deliver an anti-proliferative agent (paclitaxel – PAT) and an endothelial cell promoting agent (nitric oxide – NO) from abluminal and luminal surfaces of the stent, respectively. Phosphonoacetic acid, a polymer-free drug delivery platform, was initially coated on the stents. Then, the PAT and NO donor drugs were co-coated on the abluminal and luminal stent surfaces, respectively. The co-coating of drugs was collectively confirmed by the surface characterization techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), 3D optical surface profilometry, and contact angle goniometry. SEM showed that the integrity of the co-coating of drugs was maintained without delamination or cracks formation occurring during the stent expansion experiments. In vitro drug release studies showed that the PAT was released from the abluminal stent surfaces in a biphasic manner, which is an initial burst followed by a slow and sustained release. The NO was burst released from the luminal stent surfaces. Thus, this study demonstrated the co-delivery of PAT and NO from abluminal and luminal stent surfaces, respectively. The stent developed in this study has potential applications in inhibiting neointimal hyperplasia as well as encouraging luminal endothelialization to prevent late stent thrombosis.

  17. Formation and characterization of β-cyclodextrin (β-CD) - polyethyleneglycol (PEG) - polyethyleneimine (PEI) coated Fe3O4 nanoparticles for loading and releasing 5-Fluorouracil drug.

    Science.gov (United States)

    Prabha, G; Raj, V

    2016-05-01

    In this work, β-cyclodextrin (β-CD) - polyethyleneglycol (PEG) - polyethyleneimine (PEI) coated iron oxide nanoparticles (Fe3O4-β-CD-PEG-PEI) were developed as drug carriers for drug delivery applications. The 5- Fluorouracil (5-FU) was chosen as model drug molecule. The developed nanoparticles (Fe3O4-β-CD-PEG-PEI) were characterized by various techniques such as Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The average particles size range of 5-FU loaded Fe3O4-β-CD, Fe3O4-β-CD-PEG and Fe3O4-β-CD-PEG-PEI nanoparticles were from 151 to 300nm and zeta potential value of nanoparticles were from -43mV to -20mV as measured using Malvern Zetasizer. Finally, encapsulation efficiency (EE), loading capacity (LC) and in-vitro drug release performance of 5-FU drug loaded Fe3O4-β-CD, Fe3O4-β-CD-PEG and Fe3O4-β-CD-PEG-PEI nanoparticles was evaluated by UV-vis spectroscopy. In-vitro cytotoxicity tests investigated by MTT assay indicate that 5-FU loaded Fe3O4-β-CD-PEG-PEI nanoparticles were toxic to cancer cells and non-toxic to normal cells. The in-vitro release behavior of 5-FU from drug (5-FU) loaded Fe3O4-β-CD-PEG-PEI composite at different pH values and temperature was studied. It was found that 5-FU was released faster in pH 6.8 than in the acidic mediums (pH 1.2), and the released quantity was higher. Therefore, the newly prepared Fe3O4-β-CD-PEG-PEI carrier exhibits a promising potential capability for anticancer drug delivery in tumor therapy.

  18. Characterization of Shiga Toxin-Producing Escherichia coli Isolated from Ground Beef Collected in Different Socioeconomic Strata Markets in Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Patricia Llorente

    2014-01-01

    Full Text Available Consumption of raw/undercooked ground beef is the most common route of transmission of Shiga toxin-producing E. coli (STEC. The aim of the study was to determine the STEC contamination level of the ground beef samples collected in 36 markets of different socioeconomic strata in Buenos Aires, Argentina, and the characterization of the isolated strains. Ninety-one out of 252 (36.1% samples were stx+. Fifty-seven STEC strains were recovered. Eleven STEC strains belonged to O157 serogroup, and 46 to non-O157 serogroups. Virulence markers of the 57 STEC were stx1, 5.3% (3/57; stx2, 86.0% (49/57; stx1/stx2, 8.8% (5/57; ehxA, 61.4% (35/57; eae, 26.3% (15/57; saa, 24.6% (14/57. Shiga toxin subtypes were stx2, 31.5% (17/54; stx2c-vhb, 24.1% (13/54; stx2c-vha, 20.4% (11/54; stx2/stx2c-vha, 14.8% (8/54; stx2/stx2c-vhb, 5.6% (3/54; stx2c-vha/vhb, 3.7% (2/54. Serotypes O178:H19 and O157:H7 were prevalent. Contamination rate of STEC in all strata was high, and the highest O157 contamination was observed at low strata at several sampling rounds. Persistence of STEC was not detected. Sixteen strains (28.1% were resistant to ampicillin, streptomycin, amikacin, or tetracycline. The STEC contamination level of ground beef could vary according to the sociocultural characteristics of the population.

  19. Release and characterization of single side chains of white cabbage pectin and their complement-fixing activity

    NARCIS (Netherlands)

    Westereng, B.; Coenen, G.J.; Michaelsen, T.E.; Voragen, A.G.J.; Samuelsen, A.B.; Schols, H.A.; Knutsen, S.H.

    2009-01-01

    A mixture of single side chains from white cabbage pectin were obtained by anion exchange chromatography after applying mild chemical conditions promoting -elimination. These pectin fragments were characterized by their molecular weight distribution, sugar composition, 13C-NMR, and MALDI-TOF-MS

  20. A Bayesian method for characterizing distributed micro-releases: II. inference under model uncertainty with short time-series data.

    Energy Technology Data Exchange (ETDEWEB)

    Marzouk, Youssef; Fast P. (Lawrence Livermore National Laboratory, Livermore, CA); Kraus, M. (Peterson AFB, CO); Ray, J. P.

    2006-01-01

    Terrorist attacks using an aerosolized pathogen preparation have gained credibility as a national security concern after the anthrax attacks of 2001. The ability to characterize such attacks, i.e., to estimate the number of people infected, the time of infection, and the average dose received, is important when planning a medical response. We address this question of characterization by formulating a Bayesian inverse problem predicated on a short time-series of diagnosed patients exhibiting symptoms. To be of relevance to response planning, we limit ourselves to 3-5 days of data. In tests performed with anthrax as the pathogen, we find that these data are usually sufficient, especially if the model of the outbreak used in the inverse problem is an accurate one. In some cases the scarcity of data may initially support outbreak characterizations at odds with the true one, but with sufficient data the correct inferences are recovered; in other words, the inverse problem posed and its solution methodology are consistent. We also explore the effect of model error-situations for which the model used in the inverse problem is only a partially accurate representation of the outbreak; here, the model predictions and the observations differ by more than a random noise. We find that while there is a consistent discrepancy between the inferred and the true characterizations, they are also close enough to be of relevance when planning a response.

  1. Simulation of polar atmospheric microwave and sub-millimetre spectra for characterizing potential new ground-based observations

    Science.gov (United States)

    Newnham, David; Turner, Emma; Ford, George; Pumphrey, Hugh; Withington, Stafford

    2016-04-01

    Advanced detector technologies from the fields of astronomy and telecommunications are offering the potential to address key atmospheric science challenges with new instrumental methods. Adoption of these technologies in ground-based passive microwave and sub-millimetre radiometry could allow new measurements of chemical species and winds in the polar middle atmosphere for verifying meteorological data-sets and atmospheric models. A site study to assess the feasibility of new polar observations is performed by simulating the downwelling clear-sky submillimetre spectrum over 10-2000 GHz (30 mm to 150 microns) at two Arctic and two Antarctic locations under different seasonal and diurnal conditions. Vertical profiles for temperature, pressure and 28 atmospheric gases are constructed by combining radiosonde, meteorological reanalysis, and atmospheric chemistry model data. The sensitivity of the simulated spectra to the choice of water vapour continuum model and spectroscopic line database is explored. For the atmospheric trace species hypobromous acid (HOBr), hydrogen bromide (HBr), perhydroxyl radical (HO2) and nitrous oxide (N2O) the emission lines producing the largest change in brightness temperature are identified and minimum integration times and maximum receiver noise temperatures estimated. The optimal lines for all species are shown to vary significantly between location and scenario, strengthening the case for future hyperspectral instruments that measure over a broad frequency range. We also demonstrate the feasibility of measuring horizontal wind profiles above Halley station, Antarctica with time resolution as high as 0.5hr using simulated spectroradiometric observations of Doppler-shifted ozone (O3) and carbon monoxide (CO) lines in the 230-250 GHz region. The techniques presented provide a framework that can be applied to the retrieval of additional atmospheric parameters and be taken forward to simulate and guide the design of future microwave and sub

  2. BlueSeis3A - full characterization of a 3C broadband rotational ground motion sensor for seismology

    Science.gov (United States)

    Bernauer, Felix; Wassermann, Joachim; Frenois, Arnaud; Krissou, Rahma; Bigueur, Alexandre; Gaillot, Arnaud; de Toldi, Elliot; Ponceau, Damien; Guattari, Frederic; Igel, Heiner

    2017-04-01

    In this contribution we present a full characterization of the first three component interferometric fiber-optic gyroscope (IFOG) especially designed for the needs of seismology. The sensor is called BlueSeis3A and is manufactured by iXBlue, France. It is developed in the framework of the European Research Council Project, ROMY (Rotational motions - a new observable for seismology). To fully explore the benefits of this new seismic observable especially in the fields of volcanology, ocean bottom seismology and geophysical exploration, a portable rotational motion sensor has to fulfill certain requirements regarding dynamic range, portability, power consumption and sensitivity to changes in ambient temperature and magnetic field. For BlueSeis3A, power consumption is in an acceptable range for a portable and field deployable instrument. We will quantify sensor self noise by means of operating range diagrams as well as Allan variance and show results from tests on thermal and magnetic sensitivity. Tests on orthogonality and sensitivity to linear motion complete our full characterization.

  3. Expression and functional characterization of membrane-integrated mammalian corticotropin releasing factor receptors 1 and 2 in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Roberto Jappelli

    Full Text Available Corticotropin-Releasing Factor Receptors (CRFRs are class B1 G-protein-coupled receptors, which bind peptides of the corticotropin releasing factor family and are key mediators in the stress response. In order to dissect the receptors' binding specificity and enable structural studies, full-length human CRFR1α and mouse CRFR2β as well as fragments lacking the N-terminal extracellular domain, were overproduced in E. coli. The characteristics of different CRFR2β-PhoA gene fusion products expressed in bacteria were found to be in agreement with the predicted ones in the hepta-helical membrane topology model. Recombinant histidine-tagged CRFR1α and CRFR2β expression levels and bacterial subcellular localization were evaluated by cell fractionation and Western blot analysis. Protein expression parameters were assessed, including the influence of E. coli bacterial hosts, culture media and the impact of either PelB or DsbA signal peptide. In general, the large majority of receptor proteins became inserted in the bacterial membrane. Across all experimental conditions significantly more CRFR2β product was obtained in comparison to CRFR1α. Following a detergent screen analysis, bacterial membranes containing CRFR1α and CRFR2β were best solubilized with the zwitterionic detergent FC-14. Binding of different peptide ligands to CRFR1α and CRFR2β membrane fractions were similar, in part, to the complex pharmacology observed in eukaryotic cells. We suggest that our E. coli expression system producing functional CRFRs will be useful for large-scale expression of these receptors for structural studies.

  4. Synthesis, characterization and application of ion exchange resin as a slow-release fertilizer for wheat cultivation in space

    Science.gov (United States)

    Li, Bowei; Dong, Chen; Chu, Zhengpei; Zhang, Weizhe; Wang, Minjuan; Liu, Hong; Xie, Beizhen

    2016-10-01

    In addition to the bio-regenerative air revitalization, water recycling and waste management systems and their associated challenges, enhancing the crop yield with less fertilizer input for sustainable food production in space is also a challenge that needs to be overcome. The purpose of this study is to investigate the feasibility of applying ion exchange resin as a slow-release fertilizer for wheat cultivation in space. Strong-acid cationic exchange resins and weak-base anion exchange resins soaked in 1X, 5X, 10X and 15X Hoagland nutrient solutions, respectively, were used as fertilizers in clinoptilolite to cultivate wheat plants, and the morphological and physiological characteristics of the wheat plants were studied and compared with that of the wheat planted in vermiculite and nutrient solutions. The results showed that more ions were attached on the surface of the ion exchange resins as the solution concentration increased. After 14 days, the fresh weight of wheat planted in the ion exchange resin-clinoptilolite (IER-clinoptilolite) treated with 10X and 15X solutions were 190% and 192% higher than that of wheat planted in nutrient solution with the same concentration. Chlorophyll content of wheat plants cultivated in the two kinds of solid medium is significantly higher than that of liquid cultivation. The lowest peroxidase (POD) activity and malondialdehyde (MDA) contents of wheat plants cultivated in the IER-clinoptilolite appeared on the 14th day. According to all the experimental data, it's promising to produce slow-release nutrient fertilizer by using strong-acid cationic exchange resins and weak-base anion exchange resins for wheat cultivation in space.

  5. Lipid nanoparticles for topical and transdermal application for alopecia treatment: development, physicochemical characterization, and in vitro release and penetration studies

    Science.gov (United States)

    Gomes, Maria João; Martins, Susana; Ferreira, Domingos; Segundo, Marcela A; Reis, Salette

    2014-01-01

    Alopecia is a dermatological disorder, commonly known as hair loss, which affects up to half of the Caucasian male population by middle age, and almost all (95%) Caucasian men by old age. Considering that alopecia affects so many people and that there is currently no scientifically proven treatment with few side effects, new drug-delivery systems able to improve alopecia therapy are urgently required. With this purpose in mind, the present study aimed to develop lipid nanoparticles (nanostructured lipid carriers) with the ability to incorporate and deliver anti-alopecia active compounds (minoxidil and finasteride) into the dermis and hair follicles. Lipid nanoparticles, prepared by ultrasonication method, showed mean particle sizes around 200 nm, which is sufficient for reaching the dermis and hair follicles, and zeta potential values around −30 mV, which indicates good physical stability. Over 28 days of storage, no significant variations in these parameters were observed, which indicates that all nanoformulations are stable in storage over that period. Cryo-scanning electron microscope measurements showed that all the lipid nanoparticles exhibited a spherical shape and a smooth surface regardless of their composition. Differential scanning calorimetry studies allowed the determination of phase transition temperatures and confirmed the recrystallization of the lipid nanoparticles (recrystallization index between 11% and 86%). A high loading efficiency was achieved for finasteride (between 70% and 90%), while less than 30% was achieved for minoxidil nanoparticles, over 28 days. Controlled release assays in physiological conditions demonstrated that nanoparticles loaded with minoxidil yielded a prolonged release, as desired. Penetration assays through pig ear skin demonstrated that nanoparticles loaded with minoxidil and finasteride had low levels of penetration. These results suggest that the proposed novel formulation presents several good characteristics

  6. Development and Characterization of Sodium Hyaluronate Microparticle-Based Sustained Release Formulation of Recombinant Human Growth Hormone Prepared by Spray-Drying.

    Science.gov (United States)

    Kim, Sun J; Kim, Chan W

    2016-02-01

    The purpose of this study was to develop and characterize a sodium hyaluronate microparticle-based sustained release formulation of recombinant human growth hormone (SR-rhGH) prepared by spray-drying. Compared to freeze-drying, spray-dried SR-rhGH showed not only prolonged release profiles but also better particle property and injectability. The results of size-exclusion high-performance liquid chromatography showed that no aggregate was detected, and dimer was just about 2% and also did not increase with increase of inlet temperature up to 150 °C. Meanwhile, the results of reversed-phase high-performance liquid chromatography revealed that related proteins increased slightly from 4.6% at 100 °C to 6.3% at 150 °C. Thermal mapping test proved that product temperature did not become high to cause protein degradation during spray-drying because thermal energy was used for the evaporation of surface moisture of droplets. The structural characterization by peptide mapping, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and circular dichroism revealed that the primary, secondary, and tertiary structures of rhGH in SR-rhGH were highly comparable to those of reference somatropin materials. The biological characterization by rat weight gain and cell proliferation assays provided that bioactivity of SR-rhGH was equivalent to that of native hGH. These data establish that spray-dried SR-rhGH is highly stable by preserving intact rhGH and hyaluronate microparticle-based formulation by spray-drying can be an alternative delivery system for proteins.

  7. Molecular and toxigenic characterization of Bacillus cereus and Bacillus thuringiensis strains isolated from commercial ground roasted coffee.

    Science.gov (United States)

    Chaves, Jeane Quintanilha; Cavados, Clara de Fátima Gomes; Vivoni, Adriana Marcos

    2012-03-01

    Thirty samples of roasted ground coffee beans from 10 different commercial brands were analyzed to investigate the occurrence and levels of Bacillus cereus and Bacillus thuringiensis strains. Strains were evaluated for their genetic diversity by repetitive element sequence polymorphism PCR (Rep-PCR) and for their toxigenic profiles, i.e., the presence of hblA, hblC, hblD, nheA, nheB, nheC, cytK, ces, and entFM. Survival and multiplication of B. cereus sensu lato in the ready-to-drink coffee was determined to evaluate this beverage as a possible vehicle for B. cereus infection. B. cereus was detected in 17 (56.7%) of the 30 samples, and B. thuringiensis was detected in 8 (26.7%) of the 30 samples. Five samples did not produce any characteristic growth. The most common gene, entFM, was detected in 23 strains (92%). The NHE complex (nheA, nheB, and nheC genes) was found in 19 strains (76%). The HBL complex (hblA, hblC, and hblD) was found in 16 strains (64%). All strains were negative for ces. The cytK gene was found in 16 strains (64%). The computer-assisted cluster analysis of Rep-PCR profiles using a clustering criterion of 80% similarity revealed four main clusters. Cluster 1 was the predominant and comprised three B. thuringiensis strains with 100% similarity, cluster 2 comprised two B. cereus strains (100% similarity), cluster 3 comprised two B. thuringiensis strains (90% similarity), and cluster 4 comprised one B. thuringiensis strain and one B. cereus strain (85% similarity). The cluster analysis of fingerprints generated by Rep-PCR revealed a high genetic diversity among the B. cereus strains, suggesting that the contamination could have originated from different sources. In our experiments, when sugar was added and the beverage was kept in thermic bottles there was a significant increase in B. cereus sensu lato levels, which may increase the risk of food poisoning. These results highlight the need for additional studies on this subject to better evaluate

  8. Preparation and Characterization of Release Film from Corn Starch%玉米淀粉基缓释膜的制备及表征

    Institute of Scientific and Technical Information of China (English)

    杨铁金; 王琦; 厉悦; 刘敏; 刘亚红

    2011-01-01

    [ Objective ] The research aimed to study the preparation and characterization of release film from corn starch. [ Method ] The coated fertilizer was prepared by coating material,which was synthesized by corn starch,polyvinyl alcohol (PVA) and additives. Effects of additives included in coating materials on the slow-release fertilizer were studied in detail. The construction of the membrane was analyzed and characterized by IR spectrum and TG. The effectible factors and optimum conditions of the membranes prepared were investigated. [ Result ] The best reaction condition of the preparation of release film from corn starch was as following:starch:PVA = 1∶1 ,PVA content of 15% ,tween of 0.2 ml,urea of 0.5 g, glycerin of 1.5 g, formaldehyde of 2 ml, borax of 0.2 g, evocator of 0.5 %, reaction for 30 min, reaction temperature of 80 ℃.[ Conclusion ] The release film has characteristics of low cost, biodegradation, no pollution.%[目的]研究玉米淀粉基缓释膜的制备条件及特征.[方法]以玉米淀粉与聚乙烯醇为原料,在交联剂的作用下,制得包膜料液,用此料液给尿素涂膜,制得包膜尿素.通过红外光谱时膜的结构进行表征和分析,研究改性淀粉膜的形成条件和影响因素.[结果]制备玉米淀粉基缓释膜的最佳反应条件是淀粉和PVA的质量比为1:1,PVA的含量为15%,吐温0.2 ml,尿素0.5 g,丙三醇1.5 g,甲醛2ml,硼砂0.2 g,引发剂用量0.5%,反应30 min,反应温度控制在80℃.[结论]制备得到的包膜材料具有成本低、可生物降解、无环境污染等特点.

  9. Lipid nanoparticles for topical and transdermal application for alopecia treatment: development, physicochemical characterization, and in vitro release and penetration studies

    Directory of Open Access Journals (Sweden)

    Gomes MJ

    2014-03-01

    achieved for minoxidil nanoparticles, over 28 days. Controlled release assays in physiological conditions demonstrated that nanoparticles loaded with minoxidil yielded a prolonged release, as desired. Penetration assays through pig ear skin demonstrated that nanoparticles loaded with minoxidil and finasteride had low levels of penetration. These results suggest that the proposed novel formulation presents several good characteristics indicating their suitability for dermal delivery of anti-alopecia active compounds. Keywords: nanostructured lipid carriers (NLC, alopecia, anti-alopecia therapy, minoxidil, finasteride

  10. Histamine release factor from Dermanyssus gallinae (De Geer): characterization and in vitro assessment as a protective antigen.

    Science.gov (United States)

    Bartley, Kathryn; Nisbet, Alasdair J; Offer, Jill E; Sparks, Nicholas H C; Wright, Harry W; Huntley, John F

    2009-03-01

    A cDNA encoding a 174-amino-acid orthologue of a tick histamine release factor (HRF) was identified from the haematophagous poultry red mite Dermanyssus gallinae. The predicted D. gallinae HRF protein (Dg-HRF-1) sequence is highly conserved with the tick HRFs (identity 52-54%) and to a lesser degree with translationally controlled tumour proteins (TCTP) from mammals and other invertebrates (range 38-47%). Phylogenetically, Dg-HRF-1 partitions with the tick HRF clade suggesting a shared linage and potentially similar function(s). A recombinant Dg-HRF-1 protein (rDg-HRF-1) was produced and shown to induce degranulation of rat peritoneal mast cells in vitro, confirming conservation of the histamine-releasing function in D. gallinae. Polyclonal antibodies were generated in rabbits and hens to rDg-HRF-1. Western blotting demonstrated that native Dg-HRF is a soluble protein and immunohistochemical staining of mite sections revealed that the distribution of Dg-HRF, although ubiquitous, is more common in mite reproductive, digestive and synganglion tissues. A survey of hens housed continuously in a mite-infested commercial poultry unit failed to identify IgY specific for recombinant or native Dg-HRF, indicating that Dg-HRF is not exposed to the host during infestation/feeding and may therefore have potential as a vaccine using the concealed antigen approach. To test the protective capability of rDg-HRF-1, fresh heparinised chicken blood was enriched with yolk-derived anti-Dg-HRF IgY antibodies and fed to semi-starved mites using an in vitro feeding system. A statistically significant increase in mortality was shown (P=0.004) in mites fed with anti-Dg-HRF IgY after just one blood meal. The work presented here demonstrates, to our knowledge for the first time, the feasibility of vaccinating hens with recombinant D. gallinae antigens to control mite infestation and the potential of rDg-HRF-1 as a vaccine antigen.

  11. Is Spreading Depolarization Characterized by an Abrupt, Massive Release of Gibbs Free Energy from the Human Brain Cortex?

    Science.gov (United States)

    Dreier, Jens P.; Isele, Thomas; Reiffurth, Clemens; Offenhauser, Nikolas; Kirov, Sergei A.; Dahlem, Markus A.; Herreras, Oscar

    2012-01-01

    In the evolution of the cerebral cortex, the sophisticated organization in a steady state far away from thermodynamic equilibrium has produced the side effect of two fundamental pathological network events: ictal epileptic activity and spreading depolarization. Ictal epileptic activity describes the partial disruption, and spreading depolarization describes the near-complete disruption of the physiological double Gibbs–Donnan steady state. The occurrence of ictal epileptic activity in patients has been known for decades. Recently, unequivocal electrophysiological evidence has been found in patients that spreading depolarizations occur abundantly in stroke and brain trauma. The authors propose that the ion changes can be taken to estimate relative changes in Gibbs free energy from state to state. The calculations suggest that in transitions from the physiological state to ictal epileptic activity to spreading depolarization to death, the cortex releases Gibbs free energy in a stepwise fashion. Spreading depolarization thus appears as a twilight state close to death. Consistently, electrocorticographic recordings in the core of focal ischemia or after cardiac arrest display a smooth transition from the initial spreading depolarization component to the later ultraslow negative potential, which is assumed to reflect processes in cellular death. PMID:22829393

  12. PHBV/PCL Microparticles for Controlled Release of Resveratrol: Physicochemical Characterization, Antioxidant Potential, and Effect on Hemolysis of Human Erythrocytes

    Directory of Open Access Journals (Sweden)

    Jessica Bitencourt Emilio Mendes

    2012-01-01

    Full Text Available Microparticles of poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV and poly(ε-caprolactone (PCL containing resveratrol were successfully prepared by simple emulsion/solvent evaporation. All formulations showed suitable encapsulation efficiency values higher than 80%. PHBV microparticles revealed spherical shape with rough surface and presence of pores. PCL microparticles were spherically shaped with smooth surface. Fourier-transformed infrared spectra demonstrated no chemical bond between resveratrol and polymers. X-ray powder diffraction patterns and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. These PHBV/PCL microparticles delayed the dissolution profile of resveratrol. Release profiles were better fitted to biexponential equation. The hypochlorous-acid-scavenging activity and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid radical cation discoloration assay confirmed that the antioxidant activity of PHBV/PCL microparticles was kept, but was dependent on the microparticle morphology and dissolution profile. Resveratrol-loaded PHBV/PCL microparticles showed no cytotoxic effect on red blood cells.

  13. Characterization of physicochemical properties of hydroxypropyl methylcellulose (HPMC) type 2208 and their influence on prolonged drug release from matrix tablets.

    Science.gov (United States)

    Devjak Novak, S; Šporar, E; Baumgartner, S; Vrečer, F

    2012-07-01

    The key physicochemical properties of functional excipients should be identified, and the influence of their variability on the properties of the final dosage form should be evaluated during the development phase. Excipients produced by different manufacturers and/or by different manufacturing processes should have comparable properties. Hydroxypropyl methylcellulose (HPMC) with a high molecular weight is a functional excipient often used in solid matrix systems with prolonged release of active pharmaceutical ingredients (API). This study investigates whether HPMC manufactured by two manufacturers using different chemical procedures differs in particle-size distribution, particle shape, particle morphology, chemical composition, and dissolution of diclofenac sodium as a model drug. NIR spectroscopy was introduced and calibration models were developed to detect physical differences among HPMC batches from two different origins. The physical differences between HPMC samples were additionally confirmed with scanning electron microscopy (SEM), gas chromatography (GC) measurements, and dissolution testing of hydrophilic matrix tablets. Our results prove that, even if HPMC polymers manufactured from two different sources comply with the pharmacopeial specification, they significantly differ in physicochemical properties and thus influence the properties of the formulated dosage forms.

  14. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  15. Characterization of surface and ground water δ18O seasonal variation and its use for estimating groundwater residence times

    Science.gov (United States)

    Reddy, Michael M.; Schuster, Paul; Kendall, Carol; Reddy, Micaela B.

    2006-01-01

    18O is an ideal tracer for characterizing hydrological processes because it can be reliably measured in several watershed hydrological compartments. Here, we present multiyear isotopic data, i.e. 18O variations (δ18O), for precipitation inputs, surface water and groundwater in the Shingobee River Headwaters Area (SRHA), a well-instrumented research catchment in north-central Minnesota. SRHA surface waters exhibit δ18O seasonal variations similar to those of groundwaters, and seasonal δ18O variations plotted versus time fit seasonal sine functions. These seasonal δ18O variations were interpreted to estimate surface water and groundwater mean residence times (MRTs) at sampling locations near topographically closed-basin lakes. MRT variations of about 1 to 16 years have been estimated over an area covering about 9 km2 from the basin boundary to the most downgradient well. Estimated MRT error (±0·3 to ±0·7 years) is small for short MRTs and is much larger (±10 years) for a well with an MRT (16 years) near the limit of the method. Groundwater transit time estimates based on Darcy's law, tritium content, and the seasonal δ18O amplitude approach appear to be consistent within the limits of each method. The results from this study suggest that use of the δ18O seasonal variation method to determine MRTs can help assess groundwater recharge areas in small headwaters catchments.

  16. Ground-based characterization of Leucus and Polymele, two fly-by targets of the Lucy Discovery mission

    Science.gov (United States)

    Buie, Marc W.; Zangari, Amanda Marie; Marchi, Simone; Mottola, Stefano; Levison, Harold F.

    2016-10-01

    Lucy is a proposed NASA Discovery mission designed to perform close fly-bys with six Jupiter Trojan asteroids. The mission, which is currently in the Phase A development phase, is planned to launch in 2021 and arrive at the L4 Trojan cloud in 2027. We report on the results of an observational campaign of (11351) Leucus and (15094) Polymele conducted this year. The goal is to characterize their shape, spin state and photometric properties to aid in mission planning and to complement the mission data. Leucus was previously observed by French et al (2013) where they reported a 514 hour rotation period with a lightcurve amplitude as high as 1 magnitude. Our data confirm a long-period and high-amplitude lightcurve but with a period closer to 440 hours. The lightcurve shape has a symmetric double-peaked shape with a ~0.7mag peak-to-peak amplitude. Initial results for Polymele indicate a low-amplitude lightcurve at or below 0.1 mag with a period near 4 hours. Thus, the Lucy target sample includes bodies with among the slowest and fastest rotation rates. Additional observations will be required to further refine the period and pole orientation for both bodies. This year's data are especially challenging due to observing at low galactic latitude. We will report on final results of this year's campaign along with our methods for removing field confusion using optimal image subtraction and photometric calibration based on the new APASS catalog (Henden et al, 2012).

  17. Syntheses and structural characterizations of anionic borane-capped ammonia borane oligomers: evidence for ammonia borane H2 release via a base-promoted anionic dehydropolymerization mechanism.

    Science.gov (United States)

    Ewing, William C; Marchione, Allegra; Himmelberger, Daniel W; Carroll, Patrick J; Sneddon, Larry G

    2011-10-26

    Studies of the activating effect of Verkade's base, 2,8,9-triisobutyl-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane (VB), on the rate and extent of H(2) release from ammonia borane (AB) have led to the syntheses and structural characterizations of three anionic aminoborane chain-growth products that provide direct support for anionic dehydropolymerization mechanistic steps in the initial stages of base-promoted AB H(2) release reactions. The salt VBH(+)[H(3)BNH(2)BH(2)NH(2)BH(3)](-) (1) containing a linear five-membered anionic aminoborane chain was produced in 74% yield via the room-temperature reaction of a 3:1 AB/VB mixture in fluorobenzene solvent, while the branched and linear-chain seven-membered anionic aminoborane oligomers VBH(+)[HB(NH(2)BH(3))(3)](-) (2a) and VBH(+)[H(3)BNH(2)BH(2)NH(2)BH(2)NH(2)BH(3)](-) (2b) were obtained from VB/AB reactions carried out at 50 °C for 5 days when the AB/VB ratio was increased to 4:1. X-ray crystal structure determinations confirmed that these compounds are the isoelectronic and isostructural analogues of the hydrocarbons n-pentane, 3-ethylpentane, and n-heptane, respectively. The structural determinations also revealed significant interionic B-H···H-N dihydrogen-bonding interactions in these anions that could enhance dehydrocoupling chain-growth reactions. Such mechanistic pathways for AB H(2) release, involving the initial formation of the previously known [H(3)BNH(2)BH(3)](-) anion followed by sequential dehydrocoupling of B-H and H-N groups of growing borane-capped aminoborane anions with AB, are supported by the fact that 1 was observed to react with an additional AB equivalent to form 2a and 2b.

  18. Silica-Based and Borate-Based, Titania-Containing Bioactive Coatings Characterization: Critical Strain Energy Release Rate, Residual Stresses, Hardness, and Thermal Expansion.

    Science.gov (United States)

    Rodriguez, Omar; Matinmanesh, Ali; Phull, Sunjeev; Schemitsch, Emil H; Zalzal, Paul; Clarkin, Owen M; Papini, Marcello; Towler, Mark R

    2016-12-01

    Silica-based and borate-based glass series, with increasing amounts of TiO₂ incorporated, are characterized in terms of their mechanical properties relevant to their use as metallic coating materials. It is observed that borate-based glasses exhibit CTE (Coefficient of Thermal Expansion) closer to the substrate's (Ti6Al4V) CTE, translating into higher mode I critical strain energy release rates of glasses and compressive residual stresses and strains at the coating/substrate interface, outperforming the silica-based glasses counterparts. An increase in the content of TiO₂ in the glasses results in an increase in the mode I critical strain energy release rate for both the bulk glass and for the coating/substrate system, proving that the addition of TiO₂ to the glass structure enhances its toughness, while decreasing its bulk hardness. Borate-based glass BRT3, with 15 mol % TiO₂ incorporated, exhibits superior properties overall compared to the other proposed glasses in this work, as well as 45S5 Bioglass(®) and Pyrex.

  19. Prazosin-Conjugated Matrices Based on Biodegradable Polymers and α-Amino Acids—Synthesis, Characterization, and in Vitro Release Study

    Directory of Open Access Journals (Sweden)

    Ewa Oledzka

    2015-08-01

    Full Text Available Novel and promising macromolecular conjugates of the α1-adrenergic blocker prazosin were directly synthesized by covalent incorporation of the drug to matrices composed of biodegradable polymers and α-amino acids for the development of a polymeric implantable drug delivery carrier. The cyto- and genotoxicity of the synthesized matrices were evaluated using a bacterial luminescence test, protozoan assay, and Salmonella typhimurium TA1535. A new urethane bond was formed between the hydroxyl end-groups of the synthesized polymer matrices and an amine group of prazosin, using 1,1′-carbonyldiimidazole (CDI as a coupling agent. The structure of the polymeric conjugates was characterized by various spectroscopy techniques. A study of hydrogen nuclear magnetic resonance (1H-NMR and differential scanning calorimetry (DSC thermodiagrams indicated that the presence of prazosin pendant groups in the macromolecule structures increased the polymer’s rigidity alongside increasing glass transition temperature. It has been found that the kinetic release of prazosin from the obtained macromolecular conjugates, tested in vitro under different conditions, is strongly dependent on the physicochemical properties of polymeric matrices. Furthermore, the presence of a urethane bond in the macromolecular conjugates allowed for obtaining a relatively controlled release profile of the drug. The obtained results confirm that the pharmacokinetics of prazosin might be improved through the synthesis of polymeric conjugates containing biomedical polymers and α-amino acids in the macromolecule.

  20. Development of NAMI-A-loaded PLGA-mPEG Nanoparticles: Physicochemical Characterization, in vitro Drug Release and in vivo Antitumor Efficacy

    Institute of Scientific and Technical Information of China (English)

    YANG Yong-guang; LIU Du; XIA Yu; ZHOU Yan-hui; ZHONG Xue-yun; LIU Jie

    2011-01-01

    NAMI-A[imidazolium trans-tetrachloro(dimethylsulfoxide)imidazoleruthenium(Ⅲ)] shows extraordinary activities against metastatic tumors. However, the hydrolysis of NAMI-A to produce dimethyl sulfoxide(DMSO) could reduce anti-metastatic activity. To enhance the circulation time and the anti-metastatic effect of NAMI-A, NAMI-A-loaded nanoparticles were prepared by the double emulsion method and characterized by scanning electron microscopy for surface morphology, laser light scattering for size and zeta potential for surface charges. Controlled release of NAMI-A was observed in a sustained manner. Compared with free NAMI-A, NAMI-A-loaded nanopar- ticles exhibited superior antitumor effect by delaying tumor growth in T739 mice. PLGA-mPEG nanoparticles are promising for further studies as drug delivery carriers.

  1. Characterization and analysis of Devonian shales as related to release of gaseous hydrocarbons. Well V-7 Wetzel County, West Virginia

    Energy Technology Data Exchange (ETDEWEB)

    Kalyoncu, R.S.; Boyer, J.P.; Snyder, M.J.

    1979-08-15

    This program was initiated in September 1976, with the objective and scope of determining the relationships between the shale characteristics, hydrocarbon gas contents, and well location, and thereby provide a sound basis for (1) assessing the productive capacity of the Eastern Devonian Gas Shale deposits, and (2) guiding research, development and demonstration projects to enhance the recovery of natural gas from the shale deposits. Included in the scope of the program are a number of elemental tasks as a part of the Resource Inventory and Shale Characterization subprojects of DOE's Eastern Gas Shales Project designed to provide large quantities of support data for current and possibly future needs of the Project.

  2. Characterization of a sialate-O-acetylesterase (NanS) from the oral pathogen Tannerella forsythia that enhances sialic acid release by NanH, its cognate sialidase.

    Science.gov (United States)

    Phansopa, Chatchawal; Kozak, Radoslaw P; Liew, Li Phing; Frey, Andrew M; Farmilo, Thomas; Parker, Jennifer L; Kelly, David J; Emery, Robert J; Thomson, Rebecca I; Royle, Louise; Gardner, Richard A; Spencer, Daniel I R; Stafford, Graham P

    2015-12-01

    Tannerella forsythia, a Gram-negative member of the Bacteroidetes has evolved to harvest and utilize sialic acid. The most common sialic acid in humans is a mono-N-acetylated version termed Neu5Ac (5-N-acetyl-neuraminic acid). Many bacteria are known to access sialic acid using sialidase enzymes. However, in humans a high proportion of sialic acid contains a second acetyl group attached via an O-group, i.e. chiefly O-acetylated Neu5,9Ac2 or Neu5,4Ac2. This diacetylated sialic acid is not cleaved efficiently by many sialidases and in order to access diacetylated sialic acid, some organisms produce sialate-O-acetylesterases that catalyse the removal of the second acetyl group. In the present study, we performed bioinformatic and biochemical characterization of a putative sialate-O-acetylesterase from T. forsythia (NanS), which contains two putative SGNH-hydrolase domains related to sialate-O-acetylesterases from a range of organisms. Purification of recombinant NanS revealed an esterase that has activity against Neu5,9Ac2 and its glycolyl form Neu5Gc,9Ac. Importantly, the enzyme did not remove acetyl groups positioned at the 4-O position (Neu5,4Ac2). In addition NanS can act upon complex N-glycans released from a glycoprotein [erythropoietin (EPO)], bovine submaxillary mucin and oral epithelial cell-bound glycans. When incubated with its cognate sialidase, NanS increased sialic acid release from mucin and oral epithelial cell surfaces, implying that this esterase improves sialic acid harvesting for this pathogen and potentially other members of the oral microbiome. In summary, we have characterized a novel sialate-O-acetylesterase that contributes to the sialobiology of this important human pathogen and has potential applications in the analysis of sialic acid diacetylation of biologics in the pharmaceutical industry.

  3. A multivariate analytical method to characterize sediment attributes from high-frequency acoustic backscatter and ground-truthing data (Jade Bay, German North Sea coast)

    Science.gov (United States)

    Biondo, Manuela; Bartholomä, Alexander

    2017-04-01

    modelled relationships were used to: 1) asses the automated segmentation performance, 2) obtain a ranking of most discriminant seabed attributes responsible for acoustic diversity, 3) select the best-fit ground-truthing information to characterize each acoustic class. Using a supervised Linear Discriminant Analysis (LDA), relationships between seabed parameters and acoustic classes discrimination were modelled, and acoustic classes for each data point were predicted. The model predicted a success rate of 63.5%. An unsupervised LDA was used to model relationships between acoustic variables and clustered seabed categories with the scope of identifying misrepresentative ground-truthing data points. The model prediction scored a success rate of 50.8%. Misclassified data points were disregarded for final classification. Analyses led to clearer, more accurate appreciation of relationship patterns and improved understanding of site-specific processes affecting the acoustic signal. Value to the qualitative classification output was added by comparing the latter with a more recent set of acoustic and ground-truthing information (2014). Classification resulted in the first acoustic sediment map ever produced in the area and offered valuable knowledge for detailed sediment variability. The method proved to be a simple, repeatable strategy that may be applied to similar work and environments.

  4. Smart Macroporous IPN Hydrogels Responsive to pH, Temperature, and Ionic Strength: Synthesis, Characterization, and Evaluation of Controlled Release of Drugs.

    Science.gov (United States)

    Dragan, Ecaterina Stela; Cocarta, Ana Irina

    2016-05-18

    Fast responsive macroporous interpenetrating polymer network (IPN) hydrogels were fabricated in this work by a sequential strategy, as follows: the first network, consisting of poly(N,N-dimethylaminoethyl methacrylate) (PDMAEM) cross-linked with N,N'-methylenebisacrylamide (BAAm), was prepared at -18 °C, the second network consisting of poly(acrylamide) (PAAm) cross-linked with BAAm, being also generated by cryogelation technique. Both single network cryogels (SNC) and IPN cryogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and water uptake. The presence of weak polycation PDMAEM endows the SNCs and the IPNs cryogels with sensitivity at numerous external stimuli such as pH, temperature, ionic strength, electric field, among which the first three were investigated in this work. It was found that the initial concentration of monomers in both networks was the key factor in tailoring the properties of IPN cryogels such as swelling kinetics, equilibrium water content (EWC), phase transition temperature and the response at ionic strength. The pore size increased after the formation of the second network, the swelling kinetics in pure water being comparable with that of the SNC, phase transition temperature being situated in the range 35-36 °C for IPN cryogels. The water uptake at equilibrium (WUeq) abruptly increased at pH network, the monomer concentration in the second network being about 10 wt %. The pH response was very much diminished when the monomer concentration was high in both networks (15 wt % in the first network, and 21 wt % in the second network). The increase of the ionic strength from 0 up to 0.3 M NaCl led to the decrease of the WUeq, for all cryogels, the level of dehydration being higher and faster for the SNC than for the corresponding IPN cryogel. The release of diclofenac sodium (DS), as a model acidic drug, triggered by pH, temperature, and ionic strength from the IPN cryogels was evaluated. A

  5. Development and characterization of local anti-inflammatory implantation for the controlled release of the hexane extract of the flower-heads of Euryops pectinatus L. (Cass.).

    Science.gov (United States)

    Nesseem, D I; Michel, C G

    2011-04-01

    A hexane extract of the flower-heads of Euryops pectinatus L. (Cass.) was formulated into local anti-inflammatory implantation patches with controlled release. Cross-linked sodium hyaluronate patches (F1-F3) and chitosan patches (F4-F6) were prepared by a casting/solvent evaporation technique. Morphological and mechanical characterizations including the components ratio, surfactant and the loaded amount of the hexane extract (50, 100, and 200 mg/kg b.wt.) were investigated. Release studies were performed during 24 h using a diffusion cell. Films with optimum in vitro release rate have been investigated for testing the anti-inflammatory activity and the sustaining effect of the formulations. The sustained anti-inflammatory effect of the hexane extract of E. pectinatus flower-heads from the selected films was studied by inducing paw edema in rats with 1% (w/v) carrageenan solution. The results indicated the compatibility of hexane extract with both sodium hyaluronate and chitosan patches forming yellowish transparent films. Based on variations in drug release profiles throughout the 24-h among the formulations (F1-F6) studies, F3 and F6 were selected for further investigation. When the films were applied 1 h before the subplantar injection of carrageenan in the hind paw of male Albino rats, formulation (F3) provided its maximum inhibition of paw edema in rats (91.3%) 4 h after edema induction whereas, formulation (F6) showed less inhibition after 4 h (70.6%). The previous two formulations (F3 and F6) produced potent results (95.3 and 89.5%, respectively) after 24 h when compared with a local market preparation containing 25% β-sitosterol used as positive control. Histophathological investigation was conducted for 1, 4, and 12 weeks to study the tissue response for the two formulations (F3 and F6) at the implantation site. Chemical investigation of the hexane extract was achieved for both unsaponifiable matter (USM) and fatty acid methyl esters (FAME) using gas

  6. Kepler Eclipsing Binary Stars. I. Catalog and Principal Characterization of 1832 Eclipsing Binaries in the First Data Release

    CERN Document Server

    Prsa, Andrej; Slawson, Robert W; Doyle, Laurance R; Welsh, William F; Orosz, Jerome A; Seager, Sara; Rucker, Michael; Mjaseth, Kimberly; Engle, Scott G; Conroy, Kyle; Jenkins, Jon M; Caldwell, Douglas A; Koch, David G; Borucki, William J

    2010-01-01

    The Kepler space mission is devoted to finding Earth-size planets in habitable zones orbiting other stars. Its large, 105-deg field-of-view features over 156,000 stars that are observed continuously to detect and characterize planet transits. Yet this high-precision instrument holds great promise for other types of objects as well. Here we present a comprehensive catalog of eclipsing binary stars observed by Kepler in the first 44 days of operation, the data which are publicly available through MAST as of 6/15/2010. The catalog contains 1832 unique objects. For each object we provide its Kepler ID (KID), ephemeris (BJD0, P0), morphology type, physical parameters (Teff, log g, E(B-V), crowding), and principal parameters (T2/T1, q, fillout factor and sin i for overcontacts, and T2/T1, (R1+R2)/a, e sin(w), e cos(w), and sin i for detached binaries). We present statistics based on the determined periods and measure an average occurence rate of eclipsing binaries to be ~1.2% across the Kepler field. We further dis...

  7. Biological characterization of a novel and potent gonadotropin releasing hormone (GnRH) antagonist LXT-101

    Institute of Scientific and Technical Information of China (English)

    Xiao-liCHI; Wen-xiaZHOU; Jun-pingCHENG; Yong-xiangZHANG; Ke-liangLIU

    2005-01-01

    AIM The biological characterization of LXT-101 was investigated in vivo using intact male rats and nude mice bearing xenografts of LNCaP prostate cancer. The effect of LXT-101 on the proliferation of androgen -sensitive prostate cancer cell LNCaP and androgen-insensitive DU145 and PC-3M in vitro was also determined. METHODS Rats were injected subcutaneously with LXT-101 while control animals received only vehicle (5% mannitol). Blood samples were collected at different time after adminis-tration of LXT-101. The androgen-dependent LNCaP prostate cancer cells were grown, mixed with Matrigel and injected subcutaneously into nude mice. Experimental group received LXT-101 injectionfor up to 4 weeks. At the end point, blood samples were drawn and the excised tumors and sex organswere weighted. The serum testosterone was determined by specific immunochemiluminescence assay using kits produced by Beckman-Counter Co. The mRNA expressions of the genes of hormone receptor related to the gonadal axis were investigated by real-time RT-PCR technique. Cell viability was determined by MTT method.

  8. Kepler Eclipsing Binary Stars. I. Catalog and Principal Characterization of 1879 Eclipsing Binaries in the First Data Release

    Science.gov (United States)

    Prša, Andrej; Batalha, Natalie; Slawson, Robert W.; Doyle, Laurance R.; Welsh, William F.; Orosz, Jerome A.; Seager, Sara; Rucker, Michael; Mjaseth, Kimberly; Engle, Scott G.; Conroy, Kyle; Jenkins, Jon; Caldwell, Douglas; Koch, David; Borucki, William

    2011-03-01

    The Kepler space mission is devoted to finding Earth-size planets orbiting other stars in their habitable zones. Its large, 105 deg2 field of view features over 156,000 stars that are observed continuously to detect and characterize planet transits. Yet, this high-precision instrument holds great promise for other types of objects as well. Here we present a comprehensive catalog of eclipsing binary stars observed by Kepler in the first 44 days of operation, the data being publicly available through MAST as of 2010 June 15. The catalog contains 1879 unique objects. For each object, we provide its Kepler ID (KID), ephemeris (BJD0, P 0), morphology type, physical parameters (T eff, log g, E(B - V)), the estimate of third light contamination (crowding), and principal parameters (T 2/T 1, q, fillout factor, and sin i for overcontacts, and T 2/T 1, (R 1 + R 2)/a, esin ω, ecos ω, and sin i for detached binaries). We present statistics based on the determined periods and measure the average occurrence rate of eclipsing binaries to be ~1.2% across the Kepler field. We further discuss the distribution of binaries as a function of galactic latitude and thoroughly explain the application of artificial intelligence to obtain principal parameters in a matter of seconds for the whole sample. The catalog was envisioned to serve as a bridge between the now public Kepler data and the scientific community interested in eclipsing binary stars.

  9. Characterization of the Eyjafjallajökull volcanic plume over the Iberian Peninsula by lidar remote sensing and ground-level data collection

    Science.gov (United States)

    Revuelta, M. A.; Sastre, M.; Fernández, A. J.; Martín, L.; García, R.; Gómez-Moreno, F. J.; Artíñano, B.; Pujadas, M.; Molero, F.

    2012-03-01

    In April and May 2010 the eruption of the Eyjafjallajökull volcano disrupted air traffic across Europe. The vast economic impact of this event has stirred interest on accurate plume dispersion estimation and detailed ash characterization, in order to establish a more precise threshold for safe aircraft operation. In this work we study the physical and chemical properties of volcanogenic aerosol detected at ground level at several locations over the Iberian Peninsula, nearly 3000 km away from the Icelandic volcano. Between 4 and 14 May, the volcanogenic plume was detected at ground level, identified by an increase in sulfur dioxide, particle mass concentrations, and particulate sulfate concentration, at most EMEP stations as well as at the CIEMAT site (for the sulfate concentration in PM). At the CIEMAT site, the synergic use of Raman lidar and on-site instruments provided relevant information on the evolution and properties of the plume over the central part of the Iberian Peninsula. Aerosol extinction coefficient profiles provided by the lidar station show the presence of remarkable aerosol layers between 6 May and 15 May. Provenance studies using FLEXTRA backtrajectories confirmed that most of the aerosol layers originated in the Eyjafjallajökull eruption. The large suite of semi-continuous instruments present in the latter site allowed a better characterization of the aerosol properties. Size distribution and chemical composition were continuously monitored during the event, revealing a large increase in the aerosol fine mode, in coincidence with increases in ambient sulfate concentration, while the coarse mode remained almost unaltered. These results show that the plume carried mainly fine particles, with sizes between 0.1 and 0.7 μm in diameter, in contrast with studies of the plume that affected Central Europe in April, where particles with diameters larger than 20 μm were present in the ash layers. A possible explanation for this can be related to the

  10. Ground based characterization of biomass burning aerosols during the South American Biomass Burning Analysis (SAMBBA) field experiment in Brazil during Sept - Oct 2012

    Science.gov (United States)

    Artaxo, Paulo; Ferreira de Brito, Joel; Varanda Rizzo, Luciana; Johnson, Ben; Haywood, Jim; Longo, Karla; Freitas, Saulo; Coe, Hugh

    2013-04-01

    Biomass burning is one of the major drivers for atmospheric composition in the Southern hemisphere. In Amazonia, deforestation rates have been steadily decreasing, from 27,000 Km² in 2004 to about 5,000 Km² in 2011. This large reduction (by factor 5) was not followed by similar reduction in aerosol loading in the atmosphere due to the increase in agricultural fires. AERONET measurements from 5 sites show a large year-to year variability due to climatic and socio-economic issues. Besides this strong reduction in deforestation rate, biomass burning emissions in Amazonia increases concentrations of aerosol particles, CO, ozone and other species, and also change the surface radiation balance in a significant way. To complement the long term biomass burning measurements in Amazonia, it was organized in 2012 the intensive campaign of the South American Biomass Burning Analysis (SAMBBA) experiment with an airborne and a ground based components. A sampling site was set up at Porto Velho, with measurements of aerosol size distribution, optical properties such as absorption and scattering at several wavelengths, organic aerosol characterization with an ACSM - Aerosol Chemical Speciation Monitor. CO, CO2 and O3 were also measured to characterize combustion efficiency and photochemical processes. Filters for trace elements measured by XRF and for OC/EC determined using a Sunset instrument were also collected. An AERONET CIMEL sunphotometer was operated in parallel with a multifilter radiometer (MFR). A large data set was collected from August to October 2012. PM2.5 aerosol concentrations up to 250 ug/m3 were measured, with up to 20 ug/m3 of black carbon. Ozone went up to 60 ppb at mid-day in August. At night time ozone was consumed completely most of the time. ACSM shows that more than 85% of the aerosol mass was organic with a clear diurnal pattern. The organic aerosol volatility was very variable depending on the air mass sampled over Porto Velho. Aerosol optical depth at

  11. Grounded cognition.

    Science.gov (United States)

    Barsalou, Lawrence W

    2008-01-01

    Grounded cognition rejects traditional views that cognition is computation on amodal symbols in a modular system, independent of the brain's modal systems for perception, action, and introspection. Instead, grounded cognition proposes that modal simulations, bodily states, and situated action underlie cognition. Accumulating behavioral and neural evidence supporting this view is reviewed from research on perception, memory, knowledge, language, thought, social cognition, and development. Theories of grounded cognition are also reviewed, as are origins of the area and common misperceptions of it. Theoretical, empirical, and methodological issues are raised whose future treatment is likely to affect the growth and impact of grounded cognition.

  12. Polyelectrolyte complexes of N,N,N-trimethyl chitosan/heparin obtained at different p H: I. Preparation, characterization and controlled release of heparin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    N,N,N-trimethyl chitosan (TMC) was synthesized through the N-methylation of chitosan (CHT) and characterized by FTIR spectroscopy. Polyelectrolytes complexes (PECs) based on TMC and Heparin (HP) were prepared at different pHs (5, 8, 10 and 12) and characterized through FTIR spectroscopy, DSC and TGA curves and WAXS profiles. It was verified that the thermal stability of PECs is higher as higher is the pH of feed solution used for PEC formation. At basic conditions the complexation between TMC and HP is more effective and alterations on WAXS profiles of PECs in relation to the precursor (TMC) were clearly observed. Also, WAXS profiles show that the PEC crystallinity depends on the pH used for the complexation. These results match to the FTIR, DSC and TGA data. Due to the more intense electrostatic interactions, at higher pHs the unlike polymers chains (TMC and HP) are closer enough to produce more stable PECs. Through of the delivery curves was showed that PEC8 is a promising material for uses in oral site-specific HP release systems. This fact is directly related to the thermal properties of PEC8. (author)

  13. Automated patch-clamp technique: increased throughput in functional characterization and in pharmacological screening of small-conductance Ca2+ release-activated Ca2+ channels.

    Science.gov (United States)

    Schrøder, Rikke L; Friis, Søren; Sunesen, Morten; Mathes, Chris; Willumsen, Niels J

    2008-08-01

    The suitability of an automated patch clamp for the characterization and pharmacological screening of calcium release-activated calcium (CRAC) channels endogenously expressed in RBL-2H3 cells was explored with the QPatch system. CRAC currents (I( CRAC)) are small, and thus precise recordings require high signal-to-noise ratios obtained by high seal resistances. Automated whole-cell establishment resulted in membrane resistances of 1728 +/- 226 MOmega (n = 44). CRAC channels were activated by a number of methods that raise intracellular calcium concentration, including EGTA, ionomycin, Ins(1,4,5)P3, and thapsigargin. I(CRAC) whole-cell currents ranged from 30 to 120 pA with rise times of 40 to 150 s. An initial delay in current activation was observed in particular when I(CRAC) was activated by passive store depletion using EGTA. Apparent rundown of I(CRAC) was commonly observed, and the current could be reactivated by subsequent addition of thapsigargin. I(CRAC) was blocked by SKF-96365 and 2-APB with IC50 values of 4.7 +/- 1.1 microM (n = 9) and 7.5 +/- 0.7 (n = 9) microM, respectively. The potencies of these blockers were similar to values reported for I(CRAC) in similar conventional patch-clamp experiments. The study demonstrates that CRAC channels can be rapidly and efficiently targeted with automated patch-clamp techniques for characterization of physiological and pharmacological properties.

  14. Structural characterization of an intestinal immune system-modulating arabino-3,6-galactan-like polysaccharide from the above-ground part of Astragalus membranaceus (Bunge).

    Science.gov (United States)

    Lim, Jung Dae; Yu, Chang Yeon; Kim, Seung Hyun; Chung, Ill Min

    2016-01-20

    Arabino-3,6-galactan (AMA-1-b-PS2), an intestinal immunomodulatory compound, was purified from the above-ground portion of Astragalus membranaceus (Bunge). Its structure was characterized using sequential enzymatic digestion with exo-α-L-arabinofuranosidase (AFase) and exo-β-D-(1 → 3)-galactanase (GNase), producing small amounts of intermediate-sized and shorter oligosaccharide (AF-PS2-G2 and AF-PS2-G3) fractions, and a large GNase-resistant fraction (AF-PS2-G1). Simultaneous AFase and GNase digestion of the enzyme-resistant fraction produced two long fragments (AF3-PS2-G1-1-1 and AF3-PS2-G1-1-2). Products of GNase digestion of the upper fractions showed decreased intestinal immunomodulatory activity; the GNase-resistant fraction (AF-PS2-G1) retained significant activity. Sugar component, methylation, and FAB-MS analyses indicated that the oligosaccharides consisted of hexosyl tri- to hexa-decasaccharides and hexosyl di- to hepta-saccharides mainly comprising 6-linked Gal(f) and Gal(p); some were partially mono- or di-arabinosylated. These oligosaccharide fractions were attached to the non-reducing terminus of the β-D-(1 → 3)-galactan backbone as side chains at position 6. AMA-1-b-PS2 likely modulates both the systemic and gastric mucosal immune systems.

  15. Characterization of Alkaline Treatment and Fiber Content on the Physical, Thermal, and Mechanical Properties of Ground Coffee Waste/Oxobiodegradable HDPE Biocomposites

    Directory of Open Access Journals (Sweden)

    Ming Yee Tan

    2017-01-01

    Full Text Available Effect of alkali treatment on ground coffee waste/oxobiodegradable HDPE (GCW/oxo-HDPE composites was evaluated using 5%, 10%, 15%, and 20% volume fraction of GCW. The composites were characterized using structural (Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM, thermal (thermogravimetric analysis (TGA and differential scanning calorimetry (DSC, mechanical (tensile and impact test properties, and water absorption. FTIR spectrum indicated the eradication of lipids, hemicellulose, lignin, and impurities after the treatments lead to an improvement of the filler/matrix interface adhesion. This is confirmed by SEM results. Degree of crystallinity index was increased by 5% after the treatment. Thermal stability for both untreated and treated GCW composites was alike. Optimum tensile result was achieved when using 10% volume fraction with enhancement of 25% for tensile strength and 24% for tensile modulus compared to untreated composite. Specific tensile strength and modulus had improved as the composite has lower density. The highest impact properties were achieved when using 15% volume fraction that lead to an improvement of 6%. Treated GCW composites show better water resistance with 57% improvement compared to the untreated ones. This lightweight and ecofriendly biocomposite has the potential in packaging, internal automotive parts, lightweight furniture, and other composite engineering applications.

  16. Procedures for addressing uncertainty and variability in exposure to characterize potential health risk from trichloroethylene contaminated ground water at Beale Air Force Base in California

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J I; Bogen, K T; Hall, L C

    1999-10-05

    Conservative deterministic, screening-level calculations of exposure and risk commonly are used in quantitative assessments of potential human-health consequences from contaminants in environmental media. However, these calculations generally are based on multiple upper-bound point estimates of input parameters, particularly for exposure attributes, and can therefore produce results for decision makers that actually overstate the need for costly remediation. Alternatively, a more informative and quantitative characterization of health risk can be obtained by quantifying uncertainty and variability in exposure. This process is illustrated in this report for a hypothetical population at a specific site at Beale Air Force Base in California, where there is trichloroethylene (TCE) contaminated ground water and a potential for future residential use. When uncertainty and variability in exposure were addressed jointly for this case, the 95th-percentile upper-bound value of individual excess lifetime cancer risk was a factor approaching 10 lower than the most conservative deterministic estimate. Additionally, the probability of more than zero additional cases of cancer can be estimated, and in this case it is less than 0.5 for a hypothetical future residential population of up to 26,900 individuals present for any 7.6-y interval of a 70-y time period. Clearly, the results from application of this probabilistic approach can provide reasonable and equitable risk-acceptability criteria for a contaminated site.

  17. An Assessment of macro-scale in situ Raman and ultraviolet-induced fluorescence spectroscopy for rapid characterization of frozen peat and ground ice

    Science.gov (United States)

    Laing, Janelle R.; Robichaud, Hailey C.; Cloutis, Edward A.

    2016-04-01

    The search for life on other planets is an active area of research. Many of the likeliest planetary bodies, such as Europa, Enceladus, and Mars are characterized by cold surface environments and ice-rich terrains. Both Raman and ultraviolet-induced fluorescence (UIF) spectroscopies have been proposed as promising tools for the detection of various kinds of bioindicators in these environments. We examined whether macro-scale Raman and UIF spectroscopy could be applied to the analysis of unprocessed terrestrial frozen peat and clear ground ice samples for detection of bioindicators. It was found that this approach did not provide unambiguous detection of bioindicators, likely for a number of reasons, particularly due to strong broadband induced fluorescence. Other contributing factors may include degradation of organic matter in frozen peat to the point that compound-specific emitted fluorescence or Raman peaks were not resolvable. Our study does not downgrade the utility of either UIF or Raman spectroscopy for astrobiological investigations (which has been demonstrated in previous studies), but does suggest that the choice of instrumentation, operational conditions and sample preparation are important factors in ensuring the success of these techniques.

  18. Characterizations of plasticized polymeric film coatings for preparing multiple-unit floating drug delivery systems (muFDDSs with controlled-release characteristics.

    Directory of Open Access Journals (Sweden)

    Sheng-Feng Hung

    Full Text Available Effervescent multiple-unit floating drug delivery systems (muFDDSs consisting of drug (lorsartan- and effervescent (sodium bicarbonate-containing pellets were characterized in this study. The mechanical properties (stress and strain at rupture, Young's modulus, and toughness of these plasticized polymeric films of acrylic (Eudragit RS, RL, and NE and cellulosic materials (ethyl cellulose (EC, and Surelease were examined by a dynamic mechanical analyzer. Results demonstrated that polymeric films prepared from Surelease and EC were brittle with less elongation compared to acrylic films. Eudragit NE films were very flexible in both the dry and wet states. Because plasticizer leached from polymeric films during exposure to the aqueous medium, plasticization of wet Eudragit RS and RL films with 15% triethyl citrate (TEC or diethyl phthalate (DEP resulted in less elongation. DEP might be the plasticizer of choice among the plasticizers examined in this study for Eudragit RL to provide muFDDSs with a short time for all pellets to float (TPF and a longer period of floating. Eudragit RL and RS at a 1∶1 ratio plasticized with 15% DEP were optimally selected as the coating membrane for the floating system. Although the release of losartan from the pellets was still too fast as a result of losartan being freely soluble in water, muFDDSs coated with Eudragit RL and RS at a 1∶1 ratio might have potential use for the sustained release of water-insoluble or the un-ionized form of drugs from gastroretentive drug delivery systems.

  19. PLA-PEG nanocapsules radiolabeled with 99mTechnetium-HMPAO: release properties and physicochemical characterization by atomic force microscopy and photon correlation spectroscopy.

    Science.gov (United States)

    Pereira, Maira Alves; Mosqueira, Vanessa Carla Furtado; Vilela, José Mário Carneiro; Andrade, Margareth Spangler; Ramaldes, Gilson Andrade; Cardoso, Valbert Nascimento

    2008-01-01

    The present work describes the preparation, characterization and labelling of conventional and surface-modified nanocapsules (NC) with 99m Tc-HMPAO. The size, size distribution and homogeneity were determined by photon correlation spectroscopy (PCS) and zeta potential by laser doppler anemometry. The morphology and the structural organization were evaluated by atomic force microscopy (AFM). The stability and release profile of the NC were determined in vitro in plasma. The results showed that the use of methylene blue induces significant increase in the encapsulation efficiency of 99m Tc-HMPAO, from 24.4 to 49.8% in PLA NC and 22.37 to 52.93% in the case of PLA-PEG NC (P<0.05) by improving the complex stabilization. The average diameter of NC calculated by PCS varied from 216 to 323 nm, while the average diameter determined by AFM varied from 238 to 426 nm. The AFM analysis of diameter/height ratios suggested a greater homogeneity of the surface-modified PLA-PEG nanocapsules compared to PLA NC concerning their flattening properties. The in vitro release of the 99m Tc-HMPAO in plasma medium was faster for the conventional PLA NC than for the surface-modified NC. For the latter, 60% of the radioactivity remained associated with NC, even after 12h of incubation. The results suggest that the surface-modified 99m Tc-HMPAO-PLA-PEG NC was more stable against label leakage in the presence of proteins and could present better performance as radiotracer in vivo.

  20. Protein Characterization of Extracellular Microvesicles/Exosomes Released from Cytotoxin-Challenged Rat Cerebrocortical Mixed Culture and Mouse N2a Cells.

    Science.gov (United States)

    Kumar, Dhwani; Manek, Rachna; Raghavan, Vijaya; Wang, Kevin K

    2017-03-10

    A number of neuronal and glial proteins were previously found to be released in free-standing soluble form from cultured brain cells into cell-conditioned media. Here, we sought to examine if similar proteins are also contained in neural and astroglial cell-released extracellular microvesicles/exosomes (MV/E). In this study, MV/E were isolated from cell-conditioned media from control and cytotoxin-challenged rat cerebrocortical mixed culture (CTX) and mouse neuroblastoma N2a cells. Cytotoxin challenges included pro-necrosis calcium ionophore A23187, pro-apoptosis staurosporine (STS), and excitotoxin N-methyl-D-aspartate. Based on established nanoparticle characterization method (dynamic light scattering, NanoTracker, and transmission electron microscopy), we confirmed that these released vesicles are in fact characteristic representation of MV/E by morphology (lipid bilayered vesicles) and by particle size (132-142 nm for CTX and 49-77 nm for N2a cells). We indeed identified neural cell body protein UCH-L1, axonal injury marker αII-spectrin and its breakdown products (SBDPs), astroglial markers GFAP and its breakdown products (GFAP-BDP), dendritic protein BIII-tubulin, synaptic protein synaptophysin, and exosome marker Alix in microvesicles from CTX and/or N2a cells. Furthermore, SBDPs, GFAP-BDP, UCH-L1, and synaptophysin are especially dominant in MV/E isolated from cytotoxin-treated CTX cells. Similarly, SBDPs, βIII-tubulin, and UCH-L1 are more prominently observed in cytotoxin-challenged N2a cells. Lastly, when isolated MV/E from A23187- or STS-challenged N2a cells were introduced to healthy N2a culture, they are capable of evoking cytotoxicity in the latter. Taken together, our study identified that microvesicles/exosomes isolated form healthy and injured brain cells contain certain neural and astroglial proteins, as well as possibly other cytotoxic factors that are capable of propagating cytotoxic effects.

  1. Rapid detection and characterization of surface CO2 leakage through the real-time measurement of δ13C signatures in CO2 flux from the ground

    Science.gov (United States)

    Krevor, Samuel; Benson, Sally; Rella, Chris; Perrin, Jean-Christophe; Esposito, Ariel; Crosson, Eric

    2010-05-01

    characterize an intentional leakage of CO2 from an underground pipeline at the ZERT experimental facility in Bozeman, Montana. Rapid ( 1 hour) walking surveys of the entire 100m x 100m site were collected using this mobile, real-time instrument. The resulting concentration and 13C isotopic abundance maps were processed using simple yet powerful analysis techniques, permitting not only the identification of specific leakage locations, but providing the ability to distinguish petrogenic sources of CO2 from biogenic sources. At the site an approximately 100-meter horizontal well has been drilled below an alfalfa field at a depth between 1-3 meters below the surface. The well has perforations along the central 70 meters of the well. The overlying strata are highly permeable sand, silt, and topsoil. For 30 days starting July 15, 2009, CO2 was injected at a rate of 0.2 tonnes per day. The injection rate is designed to simulate leakage from a mature storage reservoir at an annual rate of between .001 and .01%. The isotopic composition of the gas from the tank is at δ13C signature of approximately -52 parts per thousand (per mil), far more negative than either atmospheric (approx. -8 per mil) or CO2 from soil respiration (approx. -26 per mil) at the site. The CO2 isotopic and concentration measurements were taken with a Picarro WS-CRDS analyzer with 1/8' tubing connected to a sampling inlet. Simultaneous with CO2 concentrations (including 13C), position data was logged using a GPS receiver. Datapoints are taken around every second. The analyzer was powered using batteries and housed in a mobile cart. The surveys consisted of traverses of the site along the length of the pipeline and extending out 100 meters on either side of the pipeline with the end of the gas inlet tube approximate 9 cm above the ground at a speed of 1-2m/sec. This simulates the type of survey that could be easily performed if the actual or potential site of a leak was known to within an area on the order of 100

  2. Ground Wars

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... infrastructures that utilize large databases with detailed individual-level information for targeting voters, and armies of dedicated volunteers and paid part-timers. Nielsen challenges the notion that political communication in America must be tightly scripted, controlled, and conducted by a select coterie...... of professionals. Yet he also quashes the romantic idea that canvassing is a purer form of grassroots politics. In today's political ground wars, Nielsen demonstrates, even the most ordinary-seeming volunteer knocking at your door is backed up by high-tech targeting technologies and party expertise. Ground Wars...

  3. Characterizing the release of different composition of dissolved organic matter in soil under acid rain leaching using three-dimensional excitation-emission matrix spectroscopy.

    Science.gov (United States)

    Liu, Li; Song, Cunyi; Yan, Zengguang; Li, Fasheng

    2009-09-01

    Although excitation-emission matrix spectroscopy (EEMS) has been widely used to characterize dissolved organic matter (DOM), there has no report that EEMS has been used to study the effects of acid rain on DOM and its composition in soil. In this work, we employed three-dimensional EEMS to characterize the compositions of DOM leached by simulated acid rain from red soil. The red soil was subjected to leaching of simulated acid rain of different acidity, and the leached DOM presented five main peaks in its EEMS: peak-A, related to humic acid-like (HA-like) material, at Ex/Em of 310-330/395-420nm; peak-B, related to UV fulvic acid-like (FA-like) material, at Ex/Em of 230-280/400-435nm; peak-C and peak-D, both related to microbial byproduct-like material, at Ex/Em of 250-280/335-355nm and 260-280/290-320nm, respectively; and peak-E, related to simple aromatic proteins, at Ex/Em of 210-240/290-340nm. EEMS analysis results indicated that most DOM could be lost from red soil in the early phase of acid rain leaching. In addition to the effects of the pH of acid rain, the loss of DOM also depended on the properties of its compositions and the solubility of their complexes with aluminum. HA-like and microbial byproduct-like materials could be more easily released from red soil by acid rain at both higher pH (4.5 and 5.6) and lower pH (2.5 and 3) than that at middle pH (3.5). On the contrary, FA-like material lost in a similar manner under the action of different acid rains with pH ranging from 2.5 to 5.6.

  4. Comparison of protein- and polysaccharide-based nanoparticles for cancer therapy: synthesis, characterization, drug release, and interaction with a breast cancer cell line.

    Science.gov (United States)

    Akbal, Öznur; Erdal, Ebru; Vural, Tayfun; Kavaz, Doğa; Denkbaş, Emir Baki

    2017-03-01

    In this study, human serum albumin (HSA) was used as a protein-based material and poly (3-hydroxybutyrate) (PHB)-carboxymethyl chitosan (CMCh) as a polysaccharide-based material for the production of nanoparticles to be used as nanocarriers in cancer therapy. HSA and PHB-CMCh nanoparticles were prepared and characterized with a Zeta Sizer, Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscope. The effects of the pH value of the suspending medium and the amounts of crosslinker and polymer concentration on nanoparticle size and size distribution were investigated. The anticancer-agent etoposide was used as a model drug and encapsulated in nanoparticles to obtain drug release profiles. The entrapment efficiency of HSA nanoparticles was found to be greater than that of PHB-CMCh nanoparticles. To achieve "active" targeting of cancer cells, the nanoparticles were modified with concanavalin A. In the final step of the study, the interaction of nanoparticles with cancer cells was investigated in cytotoxicity and cellular uptake studies.

  5. Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by Integration of Ground-Based Geophysical Permafrost Characterization and Numerical Modeling

    Science.gov (United States)

    2015-05-01

    FINAL REPORT Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by Integration of Ground-Based Geophysical...From - To) 03-2010 to 04-2015 4. TITLE AND SUBTITLE Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by...interior Alaska; hence frozen ground affects water resources, ecosystem state, landscape evolution, and soil stability. Despite its hydrologic

  6. Prevalence and characterization of cefotaxime and ciprofloxacin co-resistant Escherichia coli isolates in retail chicken carcasses and Ground Pork, China.

    Science.gov (United States)

    Xu, Xiao; Cui, Shenghui; Zhang, Fenglan; Luo, Yanping; Gu, Yihai; Yang, Baowei; Li, Fengqin; Chen, Qian; Zhou, Gang; Wang, Yeru; Pang, Lu; Lin, Lan

    2014-02-01

    Retail meat products could serve as an important medium for the transfer of multidrug resistant isolates from food-producing animals to the community. In this study, the prevalence and characteristics of cefotaxime and ciprofloxacin co-resistant Escherichia coli isolates were investigated in retail chicken and ground pork samples from four provinces of China. The isolates were subjected to phylogenetic group typing and antimicrobial susceptibility testing. All isolates were further characterized by pulsed-field gel electrophoresis to determine the genetic relatedness. These isolates were also screened for beta-lactamase genes, quinolone resistance determinants by PCR, and followed by DNA sequence analysis. Cefotaxime and ciprofloxacin co-resistant E. coli isolates with diverse genetic origins were recovered in 31.9% (106/332) of retail meat samples. E. coli isolates of phylogenetic group A were dominant (59.4%, 63/106), and all isolates showed multidrug resistant profiles. The dominant resistant profiles were AMP-CAZ-CTX-CIP-CHL-GEN-SXT-TET (n=43) and AMP-CAZ-CTX-CIP-CHL-SXT-TET (n=43). Point mutations in quinolone resistance determination regions of topoisomerases were identified in all the isolates, and most of the isolates accumulated three (n=78) or four (n=21) point mutations. Plasmid-mediated quinolone-resistant determinants were identified in 68 isolates, including oqxAB (n=66), qnrS1 (n=7), qnrS2 (n=4), and aac(6')-Ib-cr (n=9). Eight subtypes of bla(CTX-M) were identified in 103 E. coli isolates, and blaCTX-M-55 (n=90) was dominant. This study highlights that retail meat could serve as an important reservoir of cefotaxime and ciprofloxacin co-resistant E. coli isolates. It is necessary to evaluate their contribution in the community and hospital infections.

  7. Ground-based LiDAR application to characterize sea cliff instability processes along a densely populated coastline in Southern Italy

    Science.gov (United States)

    Esposito, Giuseppe; Semaan, Fouad; Salvini, Riccardo; Troise, Claudia; Somma, Renato; Matano, Fabio; Sacchi, Marco

    2017-04-01

    Sea cliff retreatment along the coastline of the Campi Flegrei volcanic area (Southern Italy) is becoming a threat for public and private structures due to the massive urbanization occurred in the last few decades. In this area, geological features of the outcropping rocks represent one of the most important factors conditioning the sea cliff retreatment. In fact, pyroclastic deposits formed by pumices, scoria, ashes and lapilli are arranged in weakly to moderately welded layers of variable thicknesses, resulting very erodible and prone to landslide processes. Available methods to evaluate topographic changes and retreat rates of sea cliffs include a variety of geomatic techniques, like terrestrial and aerial photogrammetry and LiDAR (Light Detection And Ranging). By means of such techniques, it is in fact possible to obtain high resolution topography of sea cliffs and perform multi-temporal change detection analysis. In this contribution, we present an application of Terrestrial Laser Scanning (TLS or ground-based LiDAR) aimed to identify and quantify instability processes acting along the Torrefumo coastal cliff, in the Campi Flegrei area. Specifically, we acquired a series of 3D point clouds on the years 2013 and 2016, and compared them through a cloud-to-cloud distance computation. Furthermore, a statistical analysis was applied to the change detection results. In this way, an inventory of the cliff failures occurred along the Torrefumo cliff in the 2013-2016 time span was created, as well as the spatial and volumetric distribution of these failures was evaluated. The volumetric analysis shows that large collapses occurred rarely, whereas the spatial analysis shows that the majority of failures occurred in the middle and upper parts of the cliff face. Results also show that both rock fall and surficial erosion processes contribute to the cliff retreatment, acting in turn according to the geological properties of the involved pyroclastic deposits. The presented

  8. Comparative study of transfersomes, liposomes, and niosomes for topical delivery of 5-fluorouracil to skin cancer cells: preparation, characterization, in-vitro release, and cytotoxicity analysis.

    Science.gov (United States)

    Alvi, Iqrar Ali; Madan, Jitender; Kaushik, Dinesh; Sardana, Satish; Pandey, Ravi Shankar; Ali, Asgar

    2011-09-01

    Topical 5-fluorouracil (5-FU) is used for the treatment of actinic keratosis and nonmelanoma skin cancer. Unfortunately, 5-FU per se shows a poor percutaneous permeation, thus reducing its anticancer effectiveness after topical administration. Therefore, we have constructed transfersomes, liposomes, and niosomes of 5-FU for topical applications in this investigation. Transfersomes were prepared by the solvent evaporation method, whereas liposomes and niosomes were constructed by reverse-phase evaporation method. The nanovesicles were characterized for particle size, shape, zeta potential, viscosity, entrapment efficiency, deformability, in-vitro permeation release, and kinetics and retention. Cytotoxicity study was carried out on HaCaT cells. Transfersomes (153.2 ± 10.3 nm), liposomes (120.3 ± 9.8 nm), and niosomes (250.4 ± 8.6 nm) were produced with a maximum entrapment efficiency of 82.4 ± 4.8, 45.4 ± 3.3, and 43.4 ± 3.2%, respectively. Moreover, transmission electron microscopy and atomic force microscopy assure the smooth and spherical shape of nanovesicles. Skin permeation and retention showed better permeability and retention than the nonvesiculized dosage form. The IC50 value of transfersomes (1.02 μmol/l), liposomes (6.83 μmol/l), and niosomes (9.91 μmol/l) was found to be far less than 5-FU (15.89 μmol/l) at 72 h. 5-FU-loaded transfersomes were found to be most cytotoxic on the HaCaT cell line in comparison with liposomes and niosomes. We concluded that vesiculization of 5-FU not only improves the topical delivery, but also enhances the cytotoxic effect of 5-FU. We have presented here a viable formulation of 5-FU for the management of actinic keratosis and nonmelanoma skin carcinoma.

  9. Ground-motion site effects from multimethod shear-wave velocity characterization at 16 seismograph stations deployed for aftershocks of the August 2011 Mineral, Virginia earthquake

    Science.gov (United States)

    Stephenson, William J.; Odum, Jackson K.; McNamara, Daniel E.; Williams, Robert A.; Angster, Stephen J

    2014-01-01

    We characterize shear-wave velocity versus depth (Vs profile) at 16 portable seismograph sites through the epicentral region of the 2011 Mw 5.8 Mineral (Virginia, USA) earthquake to investigate ground-motion site effects in the area. We used a multimethod acquisition and analysis approach, where active-source horizontal shear (SH) wave reflection and refraction as well as active-source multichannel analysis of surface waves (MASW) and passive-source refraction microtremor (ReMi) Rayleigh wave dispersion were interpreted separately. The time-averaged shear-wave velocity to a depth of 30 m (Vs30), interpreted bedrock depth, and site resonant frequency were estimated from the best-fit Vs profile of each method at each location for analysis. Using the median Vs30 value (270–715 m/s) as representative of a given site, we estimate that all 16 sites are National Earthquake Hazards Reduction Program (NEHRP) site class C or D. Based on a comparison of simplified mapped surface geology to median Vs30 at our sites, we do not see clear evidence for using surface geologic units as a proxy for Vs30 in the epicentral region, although this may primarily be because the units are similar in age (Paleozoic) and may have similar bulk seismic properties. We compare resonant frequencies calculated from ambient noise horizontal:vertical spectral ratios (HVSR) at available sites to predicted site frequencies (generally between 1.9 and 7.6 Hz) derived from the median bedrock depth and average Vs to bedrock. Robust linear regression of HVSR to both site frequency and Vs30 demonstrate moderate correlation to each, and thus both appear to be generally representative of site response in this region. Based on Kendall tau rank correlation testing, we find that Vs30 and the site frequency calculated from average Vs to median interpreted bedrock depth can both be considered reliable predictors of weak-motion site effects in the epicentral region.

  10. Formaldehyde-releasers in cosmetics : relationship to formaldehyde contact allergy Part 1. Characterization, frequency and relevance of sensitization, and frequency of use in cosmetics

    NARCIS (Netherlands)

    de Groot, Anton C.; White, Ian R.; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in cosmetic

  11. Formaldehyde-releasers in cosmetics : relationship to formaldehyde contact allergy Part 1. Characterization, frequency and relevance of sensitization, and frequency of use in cosmetics

    NARCIS (Netherlands)

    de Groot, Anton C.; White, Ian R.; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in cosmetic

  12. Formaldehyde-releasers in cosmetics : relationship to formaldehyde contact allergy Part 1. Characterization, frequency and relevance of sensitization, and frequency of use in cosmetics

    NARCIS (Netherlands)

    de Groot, Anton C.; White, Ian R.; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in

  13. Press Oil Final Release Survey

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, Jeffrey Jay [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ruedig, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-11

    There are forty-eight 55 gallon barrels filled with hydraulic oil that are candidates for release and recycle. This oil needs to be characterized prior to release. Principles of sampling as provided in MARSAME/MARSSIM approaches were used as guidance for sampling.

  14. 复方丹参脉冲片的制备工艺及体外释药特性研究%Preparation and release characterization in vitro of pulsed-release tablets of compound Danshen

    Institute of Scientific and Technical Information of China (English)

    李元波; 薛立安; 殷建华; 彭熙琳; 侯世祥

    2009-01-01

    目的:根据冠心病发病的时辰节律性,以复方丹参方的药效物质和作用机制为基础,制备复方丹参脉冲片并考察其体外释药特性.方法:脉冲片由含有复方丹参药物、丁二酸、羧甲基淀粉钠、乳糖和微晶纤维素的片芯外包3层衣膜构成,内层为隔离层,由Eudragit RL 100构成;中间层为溶胀层,由HPMC E5构成;外层为控释层,由Eudragit RS 100,RL 100和EC的混合物构成.结果:5种有效成分丹参素、原儿茶醛、人参皂苷Rg_1,Rb_1、三七皂苷R_1以相近的释药规律释药,脉冲片在膨胀作用的基础上,利用渗透泵、有机酸诱导和扩散机理在设定的时滞后快速释药.结论:成功制得一定时滞后快速释放的复方丹参脉冲片用于冠心病的防治,可减少"心血管事件"发生的几率.%Objective: To prepare pulsed-release tablet (PTS) according to the rhythm of coronary heart disease based on efficacy material and the mechanism of compound Danshen. Method: PTS were achieved by coating the core which contains drugs, CMS-Na, lactose, succinic acid and MCC with separation layer (Eudragit RL), swelling layer (HPMC E5), and controlled-release membrane (Eudragit RS-RL-EC). Result: The results of in vitro experiments showed that no difference was observed among the profiles of Danshensu, protocatechuic aldehyde, ginsenoside Rg_1, Rb_1, notoginsenoside R_1 release from the two-step release system. And it indicated that swelling was the basis and prerequisite for drug release from PTS, and the diffusion, organic acid-induced, and osmotic pumping mechanism were involved in drug release, but the latter they were the dominant factors. Conclusion: Successfully obtained the PTS of a certain lag-time behind the rapid release which indicate that after bed time administration of such device, the drug plasma concentration-time curve CAN meet the requirements of chronotherapy of cardiovascular disease.

  15. Chemical and structural characterization of a model Post-Termination Complex (PoTC) for the ribosome recycling reaction: Evidence for the release of the mRNA by RRF and EF-G

    Science.gov (United States)

    Iwakura, Nobuhiro; Yokoyama, Takeshi; Quaglia, Fabio; Mitsuoka, Kaoru; Mio, Kazuhiro; Shigematsu, Hideki; Shirouzu, Mikako; Kaji, Akira; Kaji, Hideko

    2017-01-01

    A model Post-Termination Complex (PoTC) used for the discovery of Ribosome Recycling Factor (RRF) was purified and characterized by cryo-electron microscopic analysis and biochemical methods. We established that the model PoTC has mostly one tRNA, at the P/E or P/P position, together with one mRNA. The structural studies were supported by the biochemical measurement of bound tRNA and mRNA. Using this substrate, we establish that the release of tRNA, release of mRNA and splitting of ribosomal subunits occur during the recycling reaction. Order of these events is tRNA release first followed by mRNA release and splitting almost simultaneously. Moreover, we demonstrate that IF3 is not involved in any of the recycling reactions but simply prevents the re-association of split ribosomal subunits. Our finding demonstrates that the important function of RRF includes the release of mRNA, which is often missed by the use of a short ORF with the Shine-Dalgarno sequence near the termination site. PMID:28542628

  16. Activated-Lignite-Based Super Large Granular Slow-Release Fertilizers Improve Apple Tree Growth: Synthesis, Characterizations, and Laboratory and Field Evaluations.

    Science.gov (United States)

    Tang, Yafu; Wang, Xinying; Yang, Yuechao; Gao, Bin; Wan, Yongshan; Li, Yuncong C; Cheng, Dongdong

    2017-07-26

    In this work, lignite, a low-grade coal, was modified using the solid-phase activation method with the aid of a Pd/CeO2 nanoparticle catalyst to improve its pore structure and nutrient absorption. Results indicate that the adsorption ability of the activated lignite to NO3(-), NH4(+), H2PO4(-), and K(+) was significantly higher than that of raw lignite. The activated lignite was successfully combined with the polymeric slow-release fertilizer, which exhibits typical slow-release behavior, to prepare the super large granular activated lignite slow-release fertilizer (SAF). In addition to the slow-release ability, the SAF showed excellent water-retention capabilities. Soil column leaching experiments further confirmed the slow-release characteristics of the SAF with fertilizer nutrient loss greatly reduced in comparison to traditional and slow-release fertilizers. Furthermore, field tests of the SAF in an orchard showed that the novel SAF was better than other tested fertilizers in improve the growth of young apple trees. Findings from this study suggest that the newly developed SAF has great potential to be used in apple cultivation and production systems in the future.

  17. Studies on Commercially Available Sustained- or Controlled-Release Theophylline Products Commonly Used: Characterization of In-vitro Dissolution Properties and Kinetics

    Directory of Open Access Journals (Sweden)

    Omar H. El-Garhy

    2014-12-01

    Full Text Available Purpose: Theophylline (TP, is an one of the most popular drugs used in the therapy of the respiratory diseases such as chronic obstructive pulmonary disease (COPD and asthma under a variety of commercially brand names of oral sustained- or controlled-release products in the local market. The objective of this work is to endow an overview of type and dissolution characteristics of various sustained- or controlled-release products presently available. Method: The dissolution characteristics of TP from its commercially available sustained- or controlled-release products were studied in simulated gastric fluid for 2 hr and in simulated intestinal fluid for 8 hr using the USP dissolution apparatus with the paddle assembly. The kinetics of the dissolution profiles were determined by analyzing the dissolution data according to 4 kinetic equation models, namely; zero-order equation, first-order equation, Higuchi square root equation and Hixson-Crowell cube root law. Results: All the investigated commercially available TP products displayed good sustained-release patterns. The dissolution rate of TP from its commercially available capsule products was higher than that of TP commercially available tablet products. Further, the progress increase in the dissolution rate of TP from its commercially available capsule products along the dissolution period was more regular than that of TP commercially available tablet products. The kinetics study demonstrated that Zero-order and Hixon-Crowell’s models displayed sufficiently linearity with minimal differences between them suggesting that the release mechanism of TP from most of the investigated commercially available TP products may be a coupled release pattern between diffusion and dissolution mechanisms. Conclusion: The study demonstrated that most of the investigated commercial available TP products satisfied the requirements of good sustained-release products.

  18. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements....... The article further describes how national political debates over the Muslim presence in Denmark affect identity political manifestations within Nørrebro. By using Duncan Bell’s concept of mythscape (Bell, 2003), the article shows how some political actors idealize Nørrebro’s past to contest the present...

  19. Preparation, characterization and in vitro release study of BSA-loaded double-walled glucose-poly(lactide-co-glycolide) microspheres.

    Science.gov (United States)

    Ansary, Rezaul H; Rahman, Mokhlesur M; Awang, Mohamed B; Katas, Haliza; Hadi, Hazrina; Mohamed, Farahidah; Doolaanea, Abd Almonem; Kamaruzzaman, Yunus B

    2016-09-01

    The aim of this study was to prepare a model protein, bovine serum albumin (BSA) loaded double-walled microspheres using a fast degrading glucose core, hydroxyl-terminated poly(lactide-co-glycolide) (Glu-PLGA) and a moderate-degrading carboxyl-terminated PLGA polymers to reduce the initial burst release and to eliminate the lag phase from the release profile of PLGA microspheres. The double-walled microspheres were prepared using a modified water-in-oil-in-oil-in-water (w/o/o/w) method and single-polymer microspheres were prepared using a conventional water-in-oil-in-water (w/o/w) emulsion solvent evaporation method. The particle size, morphology, encapsulation efficiency, thermal properties, in vitro drug release and structural integrity of BSA were evaluated in this study. Double-walled microspheres prepared with Glu-PLGA and PLGA polymers with a mass ratio of 1:1 were non-porous, smooth-surfaced, and spherical in shape. A significant reduction of initial burst release was achieved for the double-walled microspheres compared to single-polymer microspheres. In addition, microspheres prepared using Glu-PLGA and PLGA polymers in a mass ratio of 1:1 exhibited continuous BSA release after the small initial burst without any lag phase. It can be concluded that the double-walled microspheres made of Glu-PLGA and PLGA polymers in a mass ratio of 1:1 can be a potential delivery system for pharmaceutical proteins.

  20. Characterization and in vitro release of cyclosporine-A from poly(D,L-lactide-co-glycolide implants obtained by solvent/extraction evaporation

    Directory of Open Access Journals (Sweden)

    Juliana Barbosa Saliba

    2012-01-01

    Full Text Available Cyclosporine-A-loaded PLGA implants were developed intended for ocular route. Implants were prepared using solvent extraction/evaporation technique followed by casting of the cake into rods in a heated surface. XRD patterns showed that cyclosporine-A was completely incorporated into PLGA. FTIR and DSC results indicated alterations on drug molecular conformation aiming to reach the most stable thermodynamic conformation at polymer/drug interface. Implants provided controlled/sustained in vitro release of the drug. During the first 7 weeks, the drug release was controlled by the diffusion of the cyclosporine-A; and between 7-23 week period, the drug diffusion and degradation of PLGA controlled the drug release.

  1. Single-Cell Phenotypic Characterization of Human Pituitary GHomas and Non-Functioning Adenomas Based on Hormone Content and Calcium Responses to Hypothalamic Releasing Hormones.

    Science.gov (United States)

    Senovilla, Laura; Núñez, Lucía; de Campos, José María; de Luis, Daniel A; Romero, Enrique; García-Sancho, Javier; Villalobos, Carlos

    2015-01-01

    Human pituitary tumors are generally benign adenomas causing considerable morbidity due to excess hormone secretion, hypopituitarism, and other tumor mass effects. Pituitary tumors are highly heterogeneous and difficult to type, often containing mixed cell phenotypes. We have used calcium imaging followed by multiple immunocytochemistry to type growth hormone secreting (GHomas) and non-functioning pituitary adenomas (NFPAs). Individual cells were typed for stored hormones and calcium responses to classic hypothalamic releasing hormones (HRHs). We found that GHomas contained growth hormone cells either lacking responses to HRHs or responding to all four HRHs. However, most GHoma cells were polyhormonal cells responsive to both thyrotropin-releasing hormone (TRH) and GH-releasing hormone. NFPAs were also highly heterogeneous. Some of them contained ACTH cells lacking responses to HRHs or polyhormonal gonadotropes responsive to LHRH and TRH. However, most NFPAs were made of cells storing no hormone and responded only to TRH. These results may provide new insights on the ontogeny of GHomas and NFPAs.

  2. Characterization of wind velocities in the wake of a full scale wind turbine using three ground-based synchronized WindScanners

    DEFF Research Database (Denmark)

    Yazicioglu, Hasan; Angelou, Nikolas; Mikkelsen, Torben Krogh;

    2016-01-01

    , installed at Risoe test field, has been measured from 0 to 2 diameters downstream. For this, three ground-based synchronised short-range WindScanners and a spinner lidar have been used. The 3D wind velocity field has been reconstructed in horizontal and vertical planes crossing the hub. The 10-min mean...... deficit is calculated both in a Nacelle and Moving Frame of Reference. The results can be used in quantitative validation of numerical wake models....

  3. Characterizing Effects and Benefits of Beam Defocus on High Energy Laser Performance Under Thermal Blooming and Turbulence Conditions for Air-to-Ground Engagements

    Science.gov (United States)

    2008-04-29

    PIB ). Returning to the issue of modeling the laser propagation from the weapon to the target, there are two primary effects that must be...bucket perspective ( PIB ), as well as accurately accounting for the interaction effect mentioned above, would improve the accuracy of these studies...of air-to-ground HEL scenarios under thermal blooming and turbulence; and (2) development of PIB scaling law codes that allow prediction of power in

  4. Performance evaluation and phylogenetic characterization of anaerobic fluidized bed reactors using ground tire and pet as support materials for biohydrogen production.

    Science.gov (United States)

    Barros, Aruana Rocha; Adorno, Maria Angela Tallarico; Sakamoto, Isabel Kimiko; Maintinguer, Sandra Imaculada; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

    2011-02-01

    This study evaluated two different support materials (ground tire and polyethylene terephthalate [PET]) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBR, which contained either ground tire (R1) or PET (R2) as support materials, were inoculated with thermally pretreated anaerobic sludge and operated at a temperature of 30°C. The AFBR were operated with a range of hydraulic retention times (HRT) between 1 and 8h. The reactor R1 operating with a HRT of 2h showed better performance than reactor R2, reaching a maximum hydrogen yield of 2.25 mol H(2)mol(-1) glucose with 1.3mg of biomass (as the total volatile solids) attached to each gram of ground tire. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of particle samples revealed that reactor R1 favored the presence of hydrogen-producing bacteria such as Clostridium, Bacillus, and Enterobacter.

  5. Cobalt release from inexpensive jewellery

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Jellesen, Morten Stendahl; Menné, Torkil

    2010-01-01

    Objectives: The aim was to study 354 consumer items using the cobalt spot test. Cobalt release was assessed to obtain a risk estimate of cobalt allergy and dermatitis in consumers who would wear the jewellery. Methods: The cobalt spot test was used to assess cobalt release from all items....... Microstructural characterization was made using scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). Results: Cobalt release was found in 4 (1.1%) of 354 items. All these had a dark appearance. SEM/EDS was performed on the four dark appearing items which showed tin-cobalt plating on these....... Conclusions: This study showed that only a minority of inexpensive jewellery purchased in Denmark released cobalt when analysed with the cobalt spot test. As fashion trends fluctuate and we found cobalt release from dark appearing jewellery, cobalt release from consumer items should be monitored in the future...

  6. A novel feruloyl esterase from rumen microbial metagenome: Gene cloning and enzyme characterization in the release of mono- and diferulic acids

    Science.gov (United States)

    A feruloyl esterase (FAE) gene was isolated from a rumen microbial metagenome, cloned into E. coli, and expressed in active form. The enzyme (RuFae4) was classified as a Type D feruloyl esterase based on its action on synthetic substrates and ability to release diferulates. The RuFae4 alone releas...

  7. Preparation, characterization, and in vitro drug release behavior of glutathione-sensitive long-circulation micelles based on polyethylene glycol prodrug.

    Science.gov (United States)

    Shi, Liyan; Ding, Kaikai; Sun, Xin; Zhang, Ling; Zeng, Tian; Yin, Yihua; Zheng, Hua

    2016-01-01

    In this paper, a kind of glutathione-sensitive polymeric micelles was prepared through assembling in aqueous solution of an amphiphilic polymeric prodrug which was synthesized by linkage of 6-mercaptopurine (6-MP) and polyethylene glycol monomethyl ether using propiolic acid as a connecting arm. The glutathione (GSH)-sensitive strategy is based on a Michael addition-elimination reaction, that is the amphiphilic polymeric prodrug which contains α, β-unsaturated carbonyl group acts as a Michael acceptor to receive the attack of nucleophile - glutathione, and undergoes elimination reaction to release the original drug. Transmission electron microscope observation showed that the polymeric micelles (PMs) had a spherical-like morphology with a mean diameter of 28 ± 3.2 nm. The dynamic light scattering investigation data exhibited that the size and distribution changes of PMs are negligible after being placed for 15 days. In vitro drug release study indicated that only less than 13% of 6-MP was released from the micelles under GSH stimulation at micromolar level, while 34.5, 53.7, and 77.8% accumulative release rates were achieved under GSH stimulation at millimolar level (1, 2 and 10 mM), respectively. The cell inhibition rate of PM solution against HL-60 cells carried out by MTT method reached 85%. The cellular uptake and the intracellular drug release of PMs in HL-60 cells were observed through determining the intracellular 6-MP content by UV-vis spectrophotometer. In vitro macrophage uptake study showed a low phagocytosis rate, indicating the long-circulation ability of the PMs.

  8. Pre-waste-emplacement ground-water travel time sensitivity and uncertainty analyses for Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, P.G.

    1993-01-01

    Yucca Mountain, Nevada is a potential site for a high-level radioactive-waste repository. Uncertainty and sensitivity analyses were performed to estimate critical factors in the performance of the site with respect to a criterion in terms of pre-waste-emplacement ground-water travel time. The degree of failure in the analytical model to meet the criterion is sensitive to the estimate of fracture porosity in the upper welded unit of the problem domain. Fracture porosity is derived from a number of more fundamental measurements including fracture frequency, fracture orientation, and the moisture-retention characteristic inferred for the fracture domain.

  9. OGLE-2015-BLG-0479LA,B: Binary Gravitational Microlens Characterized by Simultaneous Ground-based and Space-based Observation

    CERN Document Server

    Han, C; Gould, A; Zhu, Wei; Street, R A; Yee, J C; Beichman, C; Bryden, C; Novati, S Calchi; Carey, S; Fausnaugh, M; Gaudi, B S; Henderson, Calen B; Shvartzvald, Y; Wibking, B; Szymański, M K; Soszyński, I; Skowron, J; Mróz, P; Poleski, R; Pietrukowicz, P; Kozłowski, S; Ulaczyk, K; Wyrzykowski, Ł; Pawlak, M; Tsapras, Y; Hundertmark, M; Bachelet, E; Dominik, M; Bramich, D M; Cassan, A; Jaimes, R Figuera; Horne, K; Ranc, C; Schmidt, R; Snodgrass, C; Wambsganss, J; Steele, I A; Menzies, J; Mao, S; Bozza, V; Jørgensen, U G; Alsubai, K A; Ciceri, S; D'Ago, G; Haugbølle, T; Hessman, F V; Hinse, T C; Juncher, D; Korhonen, H; Mancini, L; Popovas, A; Rabus, M; Rahvar, S; Scarpetta, G; Skottfelt, J; Southworth, J; Starkey, D; Surdej, J; Wertz, O; Zarucki, M; Pogge, R W; DePoy, D L

    2016-01-01

    We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the {\\it Spitzer Space Telescope}. The light curves seen from the ground and from space exhibit a time offset of $\\sim 13$ days between the caustic spikes, indicating that the relative lens-source positions seen from the two places are displaced by parallax effects. From modeling the light curves, we measure the space-based microlens parallax. Combined with the angular Einstein radius measured by analyzing the caustic crossings, we determine the mass and distance of the lens. We find that the lens is a binary composed of two G-type stars with masses $\\sim 1.0\\ M_\\odot$ and $\\sim 0.9\\ M_\\odot$ located at a distance $\\sim 3$ kpc. In addition, we are able to constrain the complete orbital parameters of the lens thanks to the precise measurement of the microlens parallax derived from the joint analysis. In contrast to the binary event OGLE-2014-BLG-1050, which was also ob...

  10. Characterization of cysteine-degrading and H2S-releasing enzymes of higher plants - From the field to the test tube and back

    DEFF Research Database (Denmark)

    Jutta, Papenbrock; Anja, Riemenschneider; Kamp, Anja;

    2007-01-01

    in plants which might be involved in SIR, such as high levels of thiols, glucosinolates, cysteine-rich proteins, phytoalexins, elemental sulfur, or H2S. Probably more than one strategy is used by plants. Species- or even variety-dependent differences in the development of SIR are probably used. Our research...... focussed mainly on the release of H2S as defence strategy. In field experiments using different Brassica napus genotypes it was shown that the genetic differ- ences among Brassica genotypes lead to differences in sulfur content and L-cysteine desulfhydrase activity. Another field ex- periment demonstrated...... that sulfur supply and infection with Pyrenopeziza brassica influenced L-cysteine desulfhydrase activity in Brassica napus. Cysteine-degrading enzymes such as cysteine desulfhydrases are hypothesized to be involved in H2S release. Several L- and D-cysteine-specific desulfhydrase candidates have been isolated...

  11. Characterization of cysteine-degrading and H2S-releasing enzymes of higher plants - From the field to the test tube and back

    DEFF Research Database (Denmark)

    Jutta, Papenbrock; Anja, Riemenschneider; Kamp, Anja

    2007-01-01

    in plants which might be involved in SIR, such as high levels of thiols, glucosinolates, cysteine-rich proteins, phytoalexins, elemental sulfur, or H2S. Probably more than one strategy is used by plants. Species- or even variety-dependent differences in the development of SIR are probably used. Our research...... focussed mainly on the release of H2S as defence strategy. In field experiments using different Brassica napus genotypes it was shown that the genetic differ- ences among Brassica genotypes lead to differences in sulfur content and L-cysteine desulfhydrase activity. Another field ex- periment demonstrated...... that sulfur supply and infection with Pyrenopeziza brassica influenced L-cysteine desulfhydrase activity in Brassica napus. Cysteine-degrading enzymes such as cysteine desulfhydrases are hypothesized to be involved in H2S release. Several L- and D-cysteine-specific desulfhydrase candidates have been isolated...

  12. Renin release

    DEFF Research Database (Denmark)

    Schweda, Frank; Friis, Ulla; Wagner, Charlotte;

    2007-01-01

    The aspartyl-protease renin is the key regulator of the renin-angiotensin-aldosterone system, which is critically involved in salt, volume, and blood pressure homeostasis of the body. Renin is mainly produced and released into circulation by the so-called juxtaglomerular epithelioid cells, located......, salt, and volume overload. In contrast, the events controlling the function of renin-secreting cells at the organ and cellular level are markedly less clear and remain mysterious in certain aspects. The unravelling of these mysteries has led to new and interesting insights into the process of renin...

  13. Voltammetric characterization of the effect of monoamine uptake inhibitors and releasers on dopamine and serotonin uptake in mouse caudate-putamen and substantia nigra slices

    OpenAIRE

    John, Carrie E.; Jones, Sara R

    2007-01-01

    Fast scan cyclic voltammetry is an electrochemical technique used to measure dynamics of transporter-mediated monoamine uptake in real time and provides a tool to evaluate the detailed effects of monoamine uptake inhibitors and releasers on dopamine and serotonin transporter function. We measured the effects of cocaine, methylphenidate, 2β-propanoyl–3β-(4tolyl) tropane (PTT), fluoxetine, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), phentermine and fenfluramine on do...

  14. Molecular characterization of the GHRH/GHRH-R and its effect on GH synthesis and release in orange-spotted grouper (Epinephelus coioides).

    Science.gov (United States)

    Qian, Yuehua; Yan, Aifen; Lin, Haoran; Li, Wensheng

    2012-10-01

    Growth hormone-releasing hormone (GHRH) is a hypothalamic neuropeptide that stimulates growth hormone (GH) synthesis and secretion in the pituitary gland. In this paper, the full-length cDNAs of orange-spotted grouper GHRH and its receptor (GHRH-R) were cloned. The grouper GHRH cDNA is 713 bp in length and encodes a 141-aa precursor that includes an 18-aa signal peptide, a 27-aa mature GHRH mature peptide and a 47-aa carboxyl terminus. The grouper GHRH-R cDNA sequence is 1495 bp in length, encoding a 422-aa receptor with seven transmembrane domains. Tissue distribution analyses showed that both GHRH and GHRH-R mRNAs were predominantly expressed in the brain, while the GHRH-R mRNA was also abundantly detected in the pituitary gland. Both GHRH and GHRH-R mRNAs were expressed throughout embryonic development from the multi-cell stage to the newly hatched larvae stage, and the highest GHRH and GHRH-R expressions appeared at the brain vesicle stage and the heart stage, respectively. In vitro studies performed on the grouper pituitary primary cells showed that a synthetic grouper GHRH-NH(2) increased both GH mRNA expression and GH protein release in a dose-dependent manner. Together, these results suggest that the newly obtained grouper GHRH was able to stimulate GH synthesis and release, similar to its mammalian counterparts.

  15. Single-Cell Phenotypic Characterization of Human Pituitary GHomas and Non-Functioning Adenomas Based on Hormone Content and Calcium Responses to Hypothalamic Releasing Hormones

    Science.gov (United States)

    Senovilla, Laura; Núñez, Lucía; de Campos, José María; de Luis, Daniel A.; Romero, Enrique; García-Sancho, Javier; Villalobos, Carlos

    2015-01-01

    Human pituitary tumors are generally benign adenomas causing considerable morbidity due to excess hormone secretion, hypopituitarism, and other tumor mass effects. Pituitary tumors are highly heterogeneous and difficult to type, often containing mixed cell phenotypes. We have used calcium imaging followed by multiple immunocytochemistry to type growth hormone secreting (GHomas) and non-functioning pituitary adenomas (NFPAs). Individual cells were typed for stored hormones and calcium responses to classic hypothalamic releasing hormones (HRHs). We found that GHomas contained growth hormone cells either lacking responses to HRHs or responding to all four HRHs. However, most GHoma cells were polyhormonal cells responsive to both thyrotropin-releasing hormone (TRH) and GH-releasing hormone. NFPAs were also highly heterogeneous. Some of them contained ACTH cells lacking responses to HRHs or polyhormonal gonadotropes responsive to LHRH and TRH. However, most NFPAs were made of cells storing no hormone and responded only to TRH. These results may provide new insights on the ontogeny of GHomas and NFPAs. PMID:26106585

  16. Polymeric nanoparticles loaded with the 3,5,3´-triiodothyroacetic acid (Triac, a thyroid hormone: factorial design, characterization, and release kinetics

    Directory of Open Access Journals (Sweden)

    dos Santos KC

    2012-07-01

    Full Text Available Karen C dos Santos,1 Maria Fatima GF da Silva,1 Edenir R Pereira-Filho,1 Joao B Fernandes,1 Igor Polikarpov,2 Moacir R Forim11Department of Chemistry, Federal University of Sao Carlos, Sao Carlos, 2Physics Institute of Sao Carlos, University of Sao Paulo, Sao Carlos, Sao Paulo, BrazilAbstract: This present investigation deals with the development and optimization of polymeric nanoparticle systems loaded with 3,5,3´-triiodothyroacetic acid (Triac. A 211–6 fractional factorial design and another 22 factorial design were used to study the contrasts on particle size distribution, morphology, surface charge, drug content, entrapment efficiency, and in vitro drug release profiles. The independent variables were the concentration of Triac, type and quantity of both polymer and oil, quantity of Span™ 60 and Tween® 80, volume of solvent and water, and velocity of both magnetic stirring and the transfer of the organic phase into the aqueous solution. The results of optimized formulations showed a narrow size distribution with a polydispersity index lower than 0.200. The particle sizes were on average 159.6 nm and 285.6 nm for nanospheres and nanocapsules, respectively. The zeta potential was higher than 20 mV (in module and the entrapment efficiency was nearly 100%. A high-performance liquid chromatography method was developed, validated, and efficiently applied to Triac quantification in colloidal suspension. The main independent variables were the type and quantity of the polymer and oil. In vitro drug release profile depicted several features to sustain Triac release. Different formulations showed various release rates indicating an interaction between Triac and other formulation compounds such as polymer and/or oil quantity. Two different models were identified (biexponential and monoexponential that allowed the control of both the release rate and Triac concentration. Thus, the prepared nanoparticles described here may be of clinical importance

  17. A new experimental approach for characterizing the internal trapped charge and electric field build up in ground-coated insulators during their e sup - irradiation

    CERN Document Server

    Jbara, O; Belhaj, M; Cazaux, J; Rau, E I; Filippov, M; Andrianov, M V

    2002-01-01

    An original method is proposed to investigate the dynamical trapping properties of bulk insulators during their irradiation by keV electrons when they are coated with a grounded metallic film. This method is based on the measurement of the displacement current and it allows to evaluate time constants for charging and discharging the dielectric as well as to evaluate the electric field build up and trapped charge density below the coating. This method is illustrated by the estimate of the charging and discharging time constants in e sup - irradiated PMMA and the estimate of the magnitude of the electric field which drives the migration of the mobile ions in e sup - irradiated glasses.

  18. Methods for Characterizing Fine Particulate Matter Using Satellite Remote-Sensing Data and Ground Observations: Potential Use for Environmental Public Health Surveillance

    Science.gov (United States)

    Al-Hamdan, Mohammad Z.; Crosson, William L.; Limaye, Ashutosh S.; Rickman, Douglas L.; Quattrochi, Dale A.; Estes, Maurice G.; Qualters, Judith R.; Niskar, Amanda S.; Sinclair, Amber H.; Tolsma, Dennis D.; Adeniyi, Kafayat A.

    2007-01-01

    This study describes and demonstrates different techniques for surfacing daily environmental / hazards data of particulate matter with aerodynamic diameter less than or equal to 2.5 micrometers (PM2.5) for the purpose of integrating respiratory health and environmental data for the Centers for Disease Control and Prevention (CDC s) pilot study of Health and Environment Linked for Information Exchange (HELIX)-Atlanta. It described a methodology for estimating ground-level continuous PM2.5 concentrations using B-Spline and inverse distance weighting (IDW) surfacing techniques and leveraging National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectrometer (MODIS) data to complement The Environmental Protection Agency (EPA) ground observation data. The study used measurements of ambient PM2.5 from the EPA database for the year 2003 as well as PM2.5 estimates derived from NASA s satellite data. Hazard data have been processed to derive the surrogate exposure PM2.5 estimates. The paper has shown that merging MODIS remote sensing data with surface observations of PM2.5 not only provides a more complete daily representation of PM2.5 than either data set alone would allow, but it also reduces the errors in the PM2.5 estimated surfaces. The results of this paper have shown that the daily IDW PM2.5 surfaces had smaller errors, with respect to observations, than those of the B-Spline surfaces in the year studied. However the IDW mean annual composite surface had more numerical artifacts, which could be due to the interpolating nature of the IDW that assumes that the maxima and minima can occur only at the observation points. Finally, the methods discussed in this paper improve temporal and spatial resolutions and establish a foundation for environmental public health linkage and association studies for which determining the concentrations of an environmental hazard such as PM2.5 with good accuracy levels is critical.

  19. Characterization and error analysis of an operational retrieval algorithm for estimating column ozone and aerosol properties from ground-based ultra-violet irradiance measurements

    Science.gov (United States)

    Taylor, Thomas E.; L'Ecuyer, Tristan; Slusser, James; Stephens, Graeme; Krotkov, Nick; Davis, John; Goering, Christian

    2005-08-01

    Extensive sensitivity and error characteristics of a recently developed optimal estimation retrieval algorithm which simultaneously determines aerosol optical depth (AOD), aerosol single scatter albedo (SSA) and total ozone column (TOC) from ultra-violet irradiances are described. The algorithm inverts measured diffuse and direct irradiances at 7 channels in the UV spectral range obtained from the United States Department of Agriculture's (USDA) UV-B Monitoring and Research Program's (UVMRP) network of 33 ground-based UV-MFRSR instruments to produce aerosol optical properties and TOC at all seven wavelengths. Sensitivity studies of the Tropospheric Ultra-violet/Visible (TUV) radiative transfer model performed for various operating modes (Delta-Eddington versus n-stream Discrete Ordinate) over domains of AOD, SSA, TOC, asymmetry parameter and surface albedo show that the solutions are well constrained. Realistic input error budgets and diagnostic and error outputs from the retrieval are analyzed to demonstrate the atmospheric conditions under which the retrieval provides useful and significant results. After optimizing the algorithm for the USDA site in Panther Junction, Texas the retrieval algorithm was run on a cloud screened set of irradiance measurements for the month of May 2003. Comparisons to independently derived AOD's are favorable with root mean square (RMS) differences of about 3% to 7% at 300nm and less than 1% at 368nm, on May 12 and 22, 2003. This retrieval method will be used to build an aerosol climatology and provide ground-truthing of satellite measurements by running it operationally on the USDA UV network database.

  20. Synthesis, characterization, drug release and transdentinal delivery studies of magnetic nanocubes coated with biodegradable poly(2-(dimethyl amino)ethyl methacrylate)

    Science.gov (United States)

    Ajkidkarn, Phranot; Ritprajak, Patcharee; Injumpa, Wishulada; Porntaveetus, Thantrira; Insin, Numpon

    2017-04-01

    Nanotechnology on magnetism and magnetic materials has been developed and studied extensively for the recent decades. Magnetic nanoparticles were applied in magnetic targeting, magnetic drug carriers, and diagnostic materials. In this work, the development of magnetic nanocomposites and their applications as drug carriers for dentistry were investigated. Well-defined ferromagnetic magnetite nanocubes (FMNCs) with the diameter of around 60 nm were synthesized using a thermal decomposition method at 290 °C with iron-oleate complexes as starting materials resulting in nanostructure with high saturation magnetization. The FMNCs were then coated with poly(2-(dimethyl amino)ethyl methacrylate) (PDMAEMA), a water-soluble, biodegradable, and pH-responsive polymer, in order to become good drug carriers with excellent dispersity in biological buffer, low cytotoxicity, and controllable drug release. The polymer coating was performed using atom transfer radical polymerization (ATRP). By using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, FMNCs/PDMAEMA showed the high compatibility in fibroblast and macrophage cell line with the cell viability of more than 80% after incubation with the highest nanocomposites concentration of 100 μg/mL for 24 h. Furthermore, the FMNCs/PDMAEMA subsequently demonstrated the anti-inflammatory effect on macrophages by suppression of pro-inflammatory cytokines, IL-6 and TNF-α production in a dose-dependent manner. The behavior of model drug alkaline hyperchlorite released from the FMNCs/PDMAEMA indicated that the drug release could be controlled by altering pH of the environment. As a result of successfully synthesized FMCNs/PDMAEMA, dentine infiltration of FMNCs/PDMAEMA was performed. It was observed that FMNCs/PDMAEMA could significantly infiltrate the dentine within 30 min under an external magnetic field. Our findings indicated the therapeutic potential of the FMNCs/PDMAEMA as transdentinal drug carriers with its

  1. Characterization of Prejunctional Muscarinic Receptors: Effects on the Release of VIP and Functional Responses and Receptor Expression in the Ovine Submandibular Gland

    Directory of Open Access Journals (Sweden)

    Anders T. Ryberg

    2009-01-01

    was collected out of the submandibular venous drainage before and during electrical stimulation of chorda tympani nerve in the absence and presence either of pirenzepine or methoctramine. While metchoctramine increased the output of protein, pirenzepine inhibited flow of saliva and increased protein output, vasodilatation, and VIP output. In morphological examinations, the inhibitory muscarinic M4 receptor occurred interacinarily in the gland. It is concluded that prejunctional muscarinic receptors, most likely of the M4 subtype, exert inhibitory modulation of the parasympathetic release of VIP in the ovine submandibular gland.

  2. Sustained-release protamine sulphate-impregnated microspheres may reduce the frequent administration of recombinant interferon α-2b in ovarian cancer: in-vitro characterization.

    Science.gov (United States)

    Gulia, Monika; Rai, Shweta; Jain, Upendra Kumar; Katare, Om Prakash; Katyal, Anju; Madan, Jitender

    2014-01-01

    Parenteral administration of recombinant interferon-α-2b (rINF-α-2b) at a dose of 50×10 IU once a week for 8 weeks is recommended for ovarian cancer. However, short half-life, small therapeutic index and proteolytic degradation cause fluctuations in plasma level and pose barriers in the development of a clinically viable dosage form. Therefore, in the present investigation, fluorescein isothiocynate-tagged rINF-α-2b was loaded into stearic acid (*rINF-α-2b-SMs), pectin (*rINF-α-2b-PMs) and gelatin (*rINF-α-2b-GMs) microspheres. Parameters such as particle size, ζ potential, encapsulation efficiency and in-vitro release were studied to follow the optimization process. The formulation, *rINF-α-2b-GMs of particle size 8.3±2.1 μm with an encapsulation efficiency of 76.0±7.4%, offered 97.4% of *rINF-α-2b release at 288 h. Thus, negatively charged extended-release formulation *rINF-α-2b-GMs was then tethered with a gradient concentration (5-20 mg/ml) of a cationic arginine-rich protein stabilizer, protamine sulphate (Pt). The nanoformulation, *rINF-α-2b-Pt-GMs-15 superimposed with 15 mg/ml of Pt, released 95.0% of *rINF-α-2b at 336 h and was designated as the optimized formulation. The optimized formulation also conserved the primary and secondary structure of *rINF-α-2b as analysed by gel electrophoresis and circular dichroism. Moreover, in-vitro cytotoxicity analysis of SKOV3 cells of the optimized nanoformulation reported significantly (one-way analysis of variance test, P<0.05) lower IC50 (414.3 IU/ml) compared with *rINF-α-2b-GMs (514.3 IU/ml) and pure rINF-α-2b (628.6 IU/ml) at 72 h by offering a prolonged cytotoxic effect. Therefore, *rINF-α-2b-Pt-GMs-15, a promising nanomedicine, warrants further in-depth in-vivo study to scale up the technology for clinical translation.

  3. Characterization of Listeria monocytogenes isolates from cattle and ground beef by pulsed-field gel electrophoresis Caracterización de aislamientos de Listeria monocytogenes obtenidos de ganado y de carne molida de vacuno por electroforesis de campo pulsado

    Directory of Open Access Journals (Sweden)

    Claudia Foerster

    2012-09-01

    Full Text Available The aims of this study were to determine the occurrence of Listeria monocytogenes in cattle feces and ground beef, to characterize these strains by pulsed-field gel electrophoresis and to compare them to three listeria strains found in humans. Cattle from different origins (n = 250 and ground beef obtained from supermarkets (n = 40 were sampled. The results show low occurrence in cattle feces (0.4 % but a higher presence in ground beef (37 %. An important part of the ground beef strains (80 % had > 95 % similarity with a strain isolated from a human sporadic case and the ATCC 19115 used as control. The strain isolated from cattle feces had 93 % similarity to clone 009, previously associated with a listeriosis outbreak related to cheese. Cattle and ground beef can harbor virulent L. monocytogenes strains. Further studies in animals and animal products are needed to improve listeriosis control.Los objetivos de este estudio fueron determinar la presencia de Listeria monocytogenes en el ganado y en la carne molida de vacuno comercializada en Chile, caracterizar los aislados mediante electroforesis de campo pulsado y compararlos con los obtenidos en tres cepas que han producido listeriosis en humanos, en ese país. Se tomaron muestras de heces de bovinos (n = 250 y de carne molida obtenida en supermercados (n = 40. Se encontró una baja incidencia de este patógeno en las heces de bovinos (0,4 %; un solo animal, pero mayores porcentajes en la carne molida (37 %. Gran parte de las cepas encontradas en la carne molida (80 % mostraron una similitud mayor del 95 % con un caso esporádico de listeriosis y con la cepa de referencia ATCC 19115. La cepa aislada de bovino tuvo un 93 % de similitud con el clon 009, responsable de un brote asociado al consumo de queso, ocurrido en 2008. Se concluye que el ganado y la carne molida pueden albergar cepas virulentas de L. monocytogenes. Se necesita un mayor número de estudios en animales y en los productos que se

  4. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    S.O. Bader

    1999-10-18

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  5. Molecular cloning, characterization, and expression analysis of a gonadotropin-releasing hormone-like cDNA in the clam, Ruditapes philippinarum.

    Science.gov (United States)

    Song, Ying; Miao, Jingjing; Cai, Yuefeng; Pan, Luqing

    2015-11-01

    Gonadotropin-releasing hormone (GnRH) is a key neuropeptide regulating reproduction in vertebrates. In the present study, we have cloned and identified the cDNA sequence of the prepro-GnRH (rp-GnRH) in the Manila clam Ruditapes philippinarum. The open reading frame encodes a protein of 94 amino acids, which consists of a signal peptide, a GnRH dodecapeptide, a cleavage site, and a GnRH-associated peptide. These deduced peptides were highly homologous to that reported for other molluscs. We used temperature control to promote gonadal development of the clams. The mRNA expression of rp-GnRH in the visceral ganglia from clams at different reproductive stages was determined by quantitative RT-PCR. The levels of steroids progesterone (P), testosterone (T), and estradiol-17β (E2) in the hemolymph of the corresponding clam were measured by ELISA. The rp-GnRH mRNA was highly expressed at the gonadal early development stage. Concentrations of P, T, and E2 also increased at the early development stage in both sexes. Positive significant correlations between rp-GnRH expression and P content as well as between rp-GnRH expression and T content were observed throughout the gonadal maturation. The results from this study may help to better understand the physiological functions of the native forms of GnRH-like peptides and the actions of GnRH on sex steroids release in bivalve molluscs.

  6. Mechano-synthesis, structural and magnetic characterization, and heat release of α-Fe nanoparticles embedded in a wüstite matrix

    Energy Technology Data Exchange (ETDEWEB)

    Batista, S.O.S.; Morales, M.A.; Santos, W.C. dos; Iglesias, C.A. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, Urca, 22290-180 Rio de Janeiro, RJ (Brazil); Carriço, A.S. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Bohn, F., E-mail: felipebohn@gmail.com [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Medeiros, S.N. de [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil)

    2015-10-01

    We report a study of the structural and magnetic properties, as well as of the heat release, of an iron/wüstite composite, prepared from iron powder and water by high energy mechanical milling. We identify that the produced sample consists of α-Fe nanoparticles embedded in a wüstite matrix and has high stability in time. Moreover, we observe that it presents noticeable features, as exchange bias effect at low temperatures and, when an alternating magnetic field is applied, its temperature reaches ∼46 °C in ∼600 s. Thus, the results and the possibility of tuning the magnetic properties of α-Fe nanoparticles embedded in a wüstite matrix, through interface interactions, place this system as a very attractive candidate for biomedical applications such as magnetic hyperthermia agent for cancer therapy. - Highlights: • We investigate the structural and magnetic properties, as well as the heat release, of an iron/wüstite composite. • The samples are produced using high energy mechanical milling. • Fe nanoparticles embedded in a wüstite matrix have high stability in time. • When an alternating magnetic field is applied, the sample temperature increases up to ∼46°C. • The composite is an interesting candidate for biomedical applications, such as magnetic hyperthermia agent for cancer therapy.

  7. Change detection and characterization of volcanic activity using ground based low-light and near infrared cameras to monitor incandescence and thermal signatures

    Science.gov (United States)

    Harrild, Martin; Webley, Peter; Dehn, Jonathan

    2015-04-01

    Knowledge and understanding of precursory events and thermal signatures are vital for monitoring volcanogenic processes, as activity can often range from low level lava effusion to large explosive eruptions, easily capable of ejecting ash up to aircraft cruise altitudes. Using ground based remote sensing techniques to monitor and detect this activity is essential, but often the required equipment and maintenance is expensive. Our investigation explores the use of low-light cameras to image volcanic activity in the visible to near infrared (NIR) portion of the electromagnetic spectrum. These cameras are ideal for monitoring as they are cheap, consume little power, are easily replaced and can provide near real-time data. We focus here on the early detection of volcanic activity, using automated scripts, that capture streaming online webcam imagery and evaluate image pixel brightness values to determine relative changes and flag increases in activity. The script is written in Python, an open source programming language, to reduce the overall cost to potential consumers and increase the application of these tools across the volcanological community. In addition, by performing laboratory tests to determine the spectral response of these cameras, a direct comparison of collocated low-light and thermal infrared cameras has allowed approximate eruption temperatures and effusion rates to be determined from pixel brightness. The results of a field campaign in June, 2013 to Stromboli volcano, Italy, are also presented here. Future field campaigns to Latin America will include collaborations with INSIVUMEH in Guatemala, to apply our techniques to Fuego and Santiaguito volcanoes.

  8. High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA

    Science.gov (United States)

    Mallinson, D.; Mahan, S.; Moore, Christine

    2008-01-01

    Geophysical surveys, sedimentology, and optically-stimulated luminescence age analyses were used to assess the geologic development of a coastal system near Swansboro, NC. This area is a significant Woodland Period Native American habitation and is designated the "Broad Reach" archaeological site. 2-d and 3-d subsurface geophysical surveys were performed using a ground penetrating radar system to define the stratigraphic framework and depositional facies. Sediment samples were collected and analyzed for grain-size to determine depositional environments. Samples were acquired and analyzed using optically stimulated luminescence techniques to derive the depositional age of the various features. The data support a low eolian to shallow subtidal coastal depositional setting for this area. Li-DAR data reveal ridge and swale topography, most likely related to beach ridges, and eolian features including low-relief, low-angle transverse and parabolic dunes, blowouts, and a low-relief eolian sand sheet. Geophysical data reveal dominantly seaward dipping units, and low-angle mounded features. Sedimentological data reveal mostly moderately-well to well-sorted fine-grained symmetrical to coarse skewed sands, suggesting initial aqueous transport and deposition, followed by eolian reworking and bioturbation. OSL data indicate initial coastal deposition prior to ca. 45,000 yBP, followed by eolian reworking and low dune stabilization at ca. 13,000 to 11,500 yBP, and again at ca. 10,000 yBP (during, and slightly after the Younger Dryas chronozone).

  9. Characterization of wind velocities in the wake of a full scale wind turbine using three ground-based synchronized WindScanners

    Science.gov (United States)

    Yazicioglu, Hasan; Angelou, Nikolas; Mikkelsen, Torben; José Trujillo, Juan

    2016-09-01

    The wind energy community is in need of detailed full-field measurements in the wake of wind turbines. Here, three dimensional(3D) wind vector field measurements obtained in the near-wake region behind a full-scale test turbine are presented. Specifically, the wake of a NEG Nordtank turbine, installed at Risoe test field, has been measured from 0 to 2 diameters downstream. For this, three ground-based synchronised short-range WindScanners and a spinner lidar have been used. The 3D wind velocity field has been reconstructed in horizontal and vertical planes crossing the hub. The 10-min mean values of the three wind components reveal detailed information regarding the wake properties while propagating downwind over flat terrain. Furthermore, the wake centre is tracked from the measurements and its meander is investigated as function of yaw misalignment of the turbine. The centre-line wake deficit is calculated both in a Nacelle and Moving Frame of Reference. The results can be used in quantitative validation of numerical wake models.

  10. Imaging tropical peatlands in Indonesia using ground penetrating radar (GPR and electrical resistivity imaging (ERI: implications for carbon stock estimates and peat soil characterization

    Directory of Open Access Journals (Sweden)

    X. Comas

    2015-01-01

    Full Text Available Current estimates of carbon (C storage in peatland systems worldwide indicate tropical peatlands comprise about 15% of the global peat carbon pool. Such estimates are uncertain due to data gaps regarding organic peat soil thickness and C content. Indonesian peatlands are considered the largest pool of tropical peat carbon (C, accounting for an estimated 65% of all tropical peat while being the largest source of carbon dioxide emissions from degrading peat worldwide, posing a major concern regarding long-term sources of greenhouse gases to the atmosphere. We combined a set of indirect geophysical methods (ground penetrating radar, GPR, and electrical resistivity imaging, ERI with direct observations from core samples (including C analysis to better understand peatland thickness in West Kalimantan (Indonesia and determine how geophysical imaging may enhance traditional coring methods for estimating C storage in peatland systems. Peatland thicknesses estimated from GPR and ERI and confirmed by coring indicated variation by less than 3% even for small peat-mineral soil interface gradients (i.e. below 0.02°. The geophysical data also provide information on peat matrix attributes such as thickness of organomineral horizons between peat and underlying substrate, the presence of wood layers, buttressed trees and soil type. These attributes could further constrain quantification of C content and aid responsible peatland management in Indonesia.

  11. Imaging tropical peatlands in Indonesia using ground penetrating radar (GPR) and electrical resistivity imaging (ERI): implications for carbon stock estimates and peat soil characterization

    Science.gov (United States)

    Comas, X.; Terry, N.; Slater, L.; Warren, M.; Kolka, R.; Kristijono, A.; Sudiana, N.; Nurjaman, D.; Darusman, T.

    2015-01-01

    Current estimates of carbon (C) storage in peatland systems worldwide indicate tropical peatlands comprise about 15% of the global peat carbon pool. Such estimates are uncertain due to data gaps regarding organic peat soil thickness and C content. Indonesian peatlands are considered the largest pool of tropical peat carbon (C), accounting for an estimated 65% of all tropical peat while being the largest source of carbon dioxide emissions from degrading peat worldwide, posing a major concern regarding long-term sources of greenhouse gases to the atmosphere. We combined a set of indirect geophysical methods (ground penetrating radar, GPR, and electrical resistivity imaging, ERI) with direct observations from core samples (including C analysis) to better understand peatland thickness in West Kalimantan (Indonesia) and determine how geophysical imaging may enhance traditional coring methods for estimating C storage in peatland systems. Peatland thicknesses estimated from GPR and ERI and confirmed by coring indicated variation by less than 3% even for small peat-mineral soil interface gradients (i.e. below 0.02°). The geophysical data also provide information on peat matrix attributes such as thickness of organomineral horizons between peat and underlying substrate, the presence of wood layers, buttressed trees and soil type. These attributes could further constrain quantification of C content and aid responsible peatland management in Indonesia.

  12. IDENTIFICATION AND CHARACTERIZATION OF FIVE NON- TRADITIONAL SOURCE CATEGORIES: CATASTROPHIC/ACCIDENTAL RELEASES, VEHICLE REPAIR FACILITIES, RECYCLING, PESTICIDE APPLICATION, AND AGRICULTURAL OPERATIONS

    Science.gov (United States)

    The report gives results of work that is part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (SIP) area source methodologies and to deve...

  13. Biochemical and pharmacological characterization of the thyrotropin releasing hormone (TRH) receptor from clonal GH sub 4 C sub 1 pituitary cells

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.J.

    1987-01-01

    The effect of drugs with anesthetic properties on the activity of the pituitary thyrotropin-releasing hormone (TRH) receptor was determined in the clonal GH{sub 4}C{sub 1} somatomammotropic cell line. Classic local anesthetics and other drugs with anesthetic activity inhibited binding of ({sup 3}H)methyl-TRH to cell receptors at concentrations known to produce anesthetic effects on the membrane. The inhibition of TRH receptor binding by tetracaine was competitive and temperature and pH dependent. Verapamil and tetracaine inhibited TRH-stimulated prolactin secretion at concentrations that inhibited peptide binding. TRH-stimulated prolactin secretion was equivalent with or without Ca{sup 2+} channel activity. Verapamil and tetracaine also inhibited basal prolactin and secretion stimulated by drugs that bypass membrane receptors, db-cAMP and TPA. These results indicate that inhibition of TRH binding and responses by diverse drugs results from an anesthetic effect on the cell membrane.

  14. SYNTHESIS AND IN VITRO CHARACTERIZATION OF HYDROXYPROPYL METHYLCELLULOSE-GRAFT-POLY (ACRYLIC ACID/2-ACRYLAMIDO-2-METHYL-1-PROPANESULFONIC ACID) POLYMERIC NETWORK FOR CONTROLLED RELEASE OF CAPTOPRIL.

    Science.gov (United States)

    Furqan Muhammad, Iqbal; Mahmood, Ahmad; Aysha, Rashid

    2016-01-01

    A super-absorbent hydrogel was developed by crosslinking of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and acrylic acid with hydroxypropyl methylcellulose (HPMC) for controlled release drug delivery of captopril, a well known antihypertensive drug. Acrylic acid and AMPS were polymerized and crosslinked with HPMC by free radical polymerization, a widely used chemical crosslinking method. N,N'-methylenebisacrylamide (MBA) and potassium persulfate (KPS) were added as cross-linker and initiator, respectively. The hydrogel formulation was loaded with captopril (as model drug). The concentration of captopril was monitored at 205 nm using UV spectrophotometer. Equilibrium swelling ratio was determined at pH 2, 4.5 and 7.4 to evaluate the pH responsiveness of the formed hydrogel. The super-absorbent hydrogels were evaluated by FTIR, SEM, XRD, and thermal analysis (DSC and TGA). The formation of new copolymeric network was determined by FTIR, XRD, TGA and DSC analysis. The hydrogel formulations with acrylic acid and AMPS ratio of 4: 1 and lower amounts of crosslinker had shown maximum swelling. Moreover, higher release rate of captopril was observed at pH 7.4 than at pH 2, because of more swelling capacity of copolymer with increasing pH of the aqueous medium. The present research work confirms the development of a stable hydrogel comprising of HPMC with acrylic acid and AMPS. The prepared hydrogels exhibited pH sensitive behav-ior. This superabsorbent composite prepared could be a successful drug carrier for treating hypertension.

  15. Characterization of gelation process and drug release profile of thermosensitive liquid lecithin/poloxamer 407 based gels as carriers for percutaneous delivery of ibuprofen.

    Science.gov (United States)

    Djekic, Ljiljana; Krajisnik, Danina; Martinovic, Martina; Djordjevic, Dragana; Primorac, Marija

    2015-07-25

    Suitability of liquid lecithin (i.e., solution of lecithin in soy bean oil with ∼ 60% w/w of phospholipids) for formation of gels, upon addition of water solution of poloxamer 407, was investigated, and formulated systems were evaluated as carriers for percutaneous delivery of ibuprofen. Formulation study of pseudo-ternary system liquid lecithin/poloxamer 407/water at constant liquid lecithin/poloxamer 407 mass ratio (2.0) revealed that minimum concentrations of liquid lecithin and poloxamer 407 required for formation of gel like systems were 15.75% w/w and 13.13% w/w, respectively, while the maximum content of water was 60.62% w/w. The systems comprising water concentrations in a range from 55 to 60.62% w/w were soft semisolids suitable for topical application, and they were selected for physicochemical and biopharmaceutical evaluation. Analysis of conductivity results and light microscopy examination revealed that investigated systems were water dilutable dispersions of spherical oligolamellar associates of phospholipids and triglyceride molecules in the copolymer water solution. Rheological behavior evaluation results indicated that the investigated gels were thermosensitive shear thinning systems. Ibuprofen (5% w/w) was incorporated by dispersing into the previously prepared carriers. Drug-loaded systems were physically stable at storage temperature from 5 ± 3°C to 40 ± 2°C, for 30 days. In vitro ibuprofen release was in accordance with the Higuchi model (rH>0.95) and sustained for 12h. The obtained results implicated that formulated LLPBGs, optimized regarding drug release and organoleptic properties, represent promising carriers for sustained percutaneous drug delivery of poorly soluble drugs. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The Triglav Glacier (South-Eastern Alps, Slovenia): Volume Estimation, Internal Characterization and 2000-2013 Temporal Evolution by Means of Ground Penetrating Radar Measurements

    Science.gov (United States)

    Del Gobbo, Costanza; Colucci, Renato R.; Forte, Emanuele; Triglav Čekada, Michaela; Zorn, Matija

    2016-08-01

    It is well known that small glaciers of mid latitudes and especially those located at low altitude respond suddenly to climate changes both on local and global scale. For this reason their monitoring as well as evaluation of their extension and volume is essential. We present a ground penetrating radar (GPR) dataset acquired on September 23 and 24, 2013 on the Triglav glacier to identify layers with different characteristics (snow, firn, ice, debris) within the glacier and to define the extension and volume of the actual ice. Computing integrated and interpolated 3D using the whole GPR dataset, we estimate that at the moment of data acquisition the ice area was 3800 m2 and the ice volume 7400 m3. Its average thickness was 1.95 m while its maximum thickness was slightly more than 5 m. Here we compare the results with a previous GPR survey acquired in 2000. A critical review of the historical data to find the general trend and to forecast a possible evolution is also presented. Between 2000 and 2013, we observed relevant changes in the internal distribution of the different units (snow, firn, ice) and the ice volume reduced from about 35,000 m3 to about 7400 m3. Such result can be achieved only using multiple GPR surveys, which allow not only to assess the volume occupied by a glacial body, but also to image its internal structure and the actual ice volume. In fact, by applying one of the widely used empirical volume-area relations to infer the geometrical parameters of the glacier, a relevant underestimation of ice-loss would be achieved.

  17. Radon as a tracer to characterize the interactions between groundwater and surface water around the ground source heat pump system in riverside area

    Science.gov (United States)

    Kim, Jaeyeon; Lee, Seong-Sun; Lee, Kang-Kun

    2016-04-01

    The interaction characteristics between groundwater and surface water was examined by using Radon-222 at Han River Environmental Research Center (HRERC) in Korea where a geothermal resource using indirect open loop ground source heat pump (GSHP) has been developed. For designing a high efficiency performance of the open loop system in shallow aquifer, the riverside area was selected for great advantage of full capacity of well. From this reason groundwater properties of the study site can be easily influenced by influx of surrounding Han River. Therefore, 12 groundwater wells were used for monitoring radon concentration and groundwater level with fluctuation of river stage from May, 2014 to Apr., 2015. The short term monitoring data showed that the radon concentration was changed in accordance with flow meter data which was reflected well by the river stage fluctuation. The spatial distribution of radon concentration from long term monitoring data was also found to be affected by water level fluctuation by nearby dam activity and seasonal effect such as heavy rainfall and groundwater pumping. The estimated residence time indicates that river flows to the study site change its direction according to the combined effect of river stage and groundwater hydrology. In the linear regression of the values, flow velocities were yielded around 0.04 to 0.25 m/day which were similar to flow meter data. These results reveal that Radon-222 can be used as an appropriate environmental tracer in examining the characteristics of interaction in consideration of fluctuating river flow on operation of GSHP in the riverside area. ACKNOWLEDGEMENT This work was supported by the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+) in "Water Resources Management Program (code 11 Technology Innovation C05)" of the MOLIT and the KAIA in Korea.

  18. Characterization of the SIRT family of NAD+-dependent protein deacetylases in the context of a mammalian model of hibernation, the thirteen-lined ground squirrel.

    Science.gov (United States)

    Rouble, Andrew N; Storey, Kenneth B

    2015-10-01

    Hibernating mammals employ strong metabolic rate depression to survive the winter, thereby avoiding the high energy costs of maintaining a euthermic lifestyle in the face of low seasonal temperatures and limited food resources. Characteristics of this natural torpor include a significant reduction in body temperature, a shift to a lipid-based metabolism, global suppression of ATP-expensive activities, and the upregulation of selected genes that mediate biochemical reorganization and cytoprotection. Sirtuin (SIRT) proteins, an evolutionarily conserved family of NAD(+)-dependent protein deacetylases, have been shown to play important roles in the post-translational regulation of many metabolic and cytoprotective processes, suggesting a potential function for these enzymes in the control of hibernation. To assess this possibility, protein levels of the seven mammalian SIRTs (SIRT1, SIRT2, SIRT3, SIRT4, SIRT5, SIRT6 and SIRT7), total SIRT activity, and the acetylation status of two downstream SIRT targets (SOD2K68 and NF-κB p65K310) were measured in skeletal muscle, liver, brown adipose and white adipose tissues of the hibernating thirteen-lined ground squirrel (Ictidomys tridecemlineatus) over the course of the torpor-arousal cycle. The analysis revealed tissue-specific responses of different SIRTs at various points throughout hibernation, including a potentially interesting correlation between increased levels of SIRT3 protein, heightened total SIRT activity, and decreased acetylation of SIRT3 downstream target SOD2K68 in skeletal muscle during late torpor. These results provide evidence to suggest a possible role for the SIRT family of protein deacetylases in the regulation of the metabolic and cellular protective pathways that mediate the process of mammalian hibernation.

  19. Characterized Fault Model of Scenario Earthquake Caused by the Itoigawa-Shizuoka Tectonic Line Fault Zone in Central Japan and Strong Ground Motion Prediction

    Science.gov (United States)

    Sato, T.; Dan, K.; Irikura, K.; Furumura, M.

    2001-12-01

    Based on the existing ideas on characterizing complex fault rupture process, we constructed four different characterized fault models for predicting strong motions from the most likely scenario earthquake along the active fault zone of the Itoigawa-Shizuoka Tectonic Line in central Japan. The Headquarters for Earthquake Research Promotion in Japanese government (2001) estimated that the earthquake (8 +/- 0.5) has the total fault length of 112 km with four segments. We assumed that the characterized fault model consisted of two regions: asperity and background (Somerville et al., 1999; Irikura, 2000; Dan et al., 2000). The main differences in the four fault models were 1) how to determine a seismic moment Mo from a fault rupture area S, 2) number of asperities N, 3) how to determine a stress parameter σ , and 4) fmax. We calculated broadband strong motions at three stations near the fault by a hybrid method of the semi-empirical and theoretical approaches. A comparison between the results from the hybrid method and those from empirical attenuation relations showed that the hybrid method using the characterized fault model could evaluate near-fault rupture directivity effects more reliably than the empirical attenuation relations. We also discussed the characterized fault models and the strong motion characteristics. The Mo extrapolated from the empirical Mo-S relation by Somerville et al. (1999) was a half of that determined from the mean value of the Wells and Coppersmith (1994) data. The latter Mo was consistent with that for the 1891 Nobi, Japan, earthquake whose fault length was almost the same as the length of the target earthquake. In addition, the fault model using the latter Mo produced a slip amount of about 6 m on the largest asperity, which was consistent with the displacement of 6 m to 9 m per event obtained from a trench survey. High-frequency strong motions were greatly influenced by the σ for the asperities (188 bars, 246 bars, 108 bars, and 134

  20. ECRB ALCOVE AND NICHE GROUND SUPPORT ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    J.W. Keifer

    1999-05-09

    The purpose of the analysis is to provide design bases for Enhanced Characterization of the Repository Block (ECRB) alcove and niche ground support drawings. The objective is to evaluate the ESF Alcove Ground Support Analysis (Ref 5.1) to determine if the calculations technically bound the ECRB alcoves and to address specific differences in the conditions and constraints.

  1. Development and characterization of the CU ground MAX-DOAS instrument: lowering RMS noise and first measurements of BrO, IO, and CHOCHO near Pensacola, FL

    Science.gov (United States)

    Coburn, S.; Dix, B.; Sinreich, R.; Volkamer, R.

    2011-01-01

    We designed and assembled the University of Colorado Ground Multi AXis Differential Optical Absorption Spectroscopy (CU GMAX-DOAS) instrument to retrieve bromine oxide (BrO), iodine oxide (IO), formaldehyde (HCHO), glyoxal (CHOCHO), nitrogen dioxide (NO2) and the oxygen dimer O4 in the coastal atmosphere of the Gulf of Mexico. The detection sensitivity of DOAS measurements is directly proportional to the root mean square (RMS) of the residual spectrum that remains after all absorbers have been subtracted. Here we describe the CU GMAX-DOAS instrument and demonstrate that the hardware is capable of attaining RMS values of ~6 × 10-6 without apparent limitations other than photon shot noise. Laboratory tests revealed two factors that, in practice, limit the RMS: (1) detector non-linearity noise, RMSNLin, and (2) temperature fluctuations that cause variations in optical resolution (full width at half the maximum, FWHM, of atomic emission lines) and give rise to optical resolution noise, RMSFWHM. The non-linearity of our detector is low (~10-3) yet - unless actively controlled - is sufficiently large to create a RMSNLin limit of up to 1.4 × 10-4. The optical resolution is sensitive to temperature changes (0.03 detector pixels/°C at 334 nm), and temperature variations of 0.1 °C can cause residual RMSFWHM of ~1 × 10-4. Both factors were actively addressed in the design of the CU GMAX-DOAS instrument. The CU GMAX-DOAS was set up at a coastal site near Pensacola, FL, where we detected BrO, IO and CHOCHO in the marine boundary layer (MBL), with daytime average tropospheric vertical column densities, VCDs, of ~2 × 1013 molec cm-2, 8 × 1012 molec cm-2 and 4 × 1014 molec cm-2, respectively. HCHO and NO2 were also detected with typical MBL VCDs of 1 × 1016 and 3 × 1015. These are the first measurements of BrO, IO and CHOCHO over the Gulf of Mexico. The atmospheric implications of these observations for elevated mercury wet deposition rates in this area are briefly

  2. PCL-PEG-PCL载姜黄素纳米粒子的制备以及体外药物释放的考察%Curcumin Loaded PCL-PEG-PCL Nanoparticle: Preparation, Characterization and in Vitro Release Study

    Institute of Scientific and Technical Information of China (English)

    郑施施; 李星熠; 王增寿

    2012-01-01

    OBJECTIVE To develop a novel biodegradable, biocompatible curcumin loaded PCEC (PCL-PEG-PCL) nanopartrcles for potential application in the drug delivery system. METHODS PCEC copolymer was synthesized by the ring-opening polymerization method and its nanoparticles (blank and curcumin loaded PCEC nanoparticles) were prepared by the emulsification-evaporation method. The developed curcumin loaded PCEC nanoparticles were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS) and etc. Drug loading capacity/efficiency was determined by HPLC. In vitro release behavior of curcumin from nanoparticles was also investigated. RESULTS The developed curcumin loaded PCEC nanoparticle showed almost spherical in shape with uniform mean particle size about 200 nm. The drug loading capacity of curcumin was appromimately (14.23±.35)%. In vitro release study showed that 65% of total curcumin was released from nanoparticle after 3 days. CONCLUSION The developed PCEC nanoparticle is an excellent carrier for the curcumin with great drug loading and encapsulation efficiency. In vitro release study indicates that the curcumin could slowly release from the nanoparticle, which might have great potential application in drug delivery system.%目的 制备一种生物可降解、生物相容性良好的姜黄素纳米粒子,并对其体外药物释放行为进行考察.方法 采用开环聚合法制备生物可降解的PCL-PEG-PCL三嵌段聚合物,然后采用乳液挥发法制备负载姜黄素的PCL-PEG-PCL纳米粒子,通过透射电镜观察所制备纳米粒子的形貌特征,动态光散射(DLS)测定粒径,采用HPLC测定纳米粒子的包封率和载药量,同时考察其体外药物释放行为.结果 姜黄素纳米粒子具有球形结构,粒径在200nm左右,载药量为(14.23±0.35)%,3d体外累积释药量65%.结论 所制备的姜黄素纳米粒子具有较高的载药量和包封率,同时体外药物释放实验证实姜黄素纳米粒子具有良好的缓释功能.

  3. Streamflow gains and losses along San Francisquito Creek and characterization of surface-water and ground-water quality, southern San Mateo and northern Santa Clara counties, California, 1996-97

    Science.gov (United States)

    Metzger, Loren F.

    2002-01-01

    San Francisquito Creek is an important source of recharge to the 22-square-mile San Francisquito Creek alluvial fan ground-water subbasin in the southern San Mateo and northern Santa Clara Counties of California. Ground water supplies as much as 20 percent of the water to some area communities. Local residents are concerned that infiltration and consequently ground-water recharge would be reduced if additional flood-control measures are implemented along San Francisquito Creek. To improve the understanding of the surface-water/ground-water interaction between San Francisquito Creek and the San Francisquito Creek alluvial fan, the U.S. Geological Survey (USGS) estimated streamflow gains and losses along San Francisquito Creek and determined the chemical quality and isotopic composition of surface and ground water in the study area.Streamflow was measured at 13 temporary streamflow-measurement stations to determine streamflow gains and losses along a 8.4-mile section of San Francisquito Creek. A series of five seepage runs between April 1996 and May 1997 indicate that losses in San Francisquito Creek were negligible until it crossed the Pulgas Fault at Sand Hill Road. Streamflow losses increased between Sand Hill Road and Middlefield Road where the alluvial deposits are predominantly coarse-grained and the water table is below the bottom of the channel. The greatest streamflow losses were measured along a 1.8-mile section of the creek between the San Mateo Drive bike bridge and Middlefield Road; average losses between San Mateo Drive and Alma Street and from there to Middlefield Road were 3.1 and 2.5 acre-feet per day, respectively.Downstream from Middlefield Road, streamflow gains and losses owing to seepage may be masked by urban runoff, changes in bank storage, and tidal effects from San Francisco Bay. Streamflow gains measured between Middlefield Road and the 1200 block of Woodland Avenue may be attributable to urban runoff and (or) ground-water inflow. Water

  4. New approach in synthesis, characterization and release study of pH-sensitive polymeric micelles, based on PLA-Lys- b-PEGm, conjugated with doxorubicin

    Science.gov (United States)

    Efthimiadou, E. K.; Tapeinos, C.; Bilalis, P.; Kordas, G.

    2011-12-01

    Amphiphilic block copolymers are well established as building blocks for the preparation of micellar drug carriers. The functional polymer micelles possess several advantages, such as high drug efficiency, targeted delivery, and minimized cytotoxicity. The synthesis of block copolymers using nano-structured templates has emerged as a useful and versatile approach for preparing drug carriers. Here, we report the synthesis of a smart polymeric compound of a diblock PLA-Lys- b-PEG copolymer containing doxorubicin. We have synthesized functionalized diblock copolymers, with lysinol, poly(lactide) and monomethoxy poly(ethylene glycol) via thermal ring-opening polymerization and a subsequent six-step substitution reaction. A variety of spectroscopic methods were employed here to verify the product of our synthesis. 1H-Nuclear magnetic resonance and Fourier transform infrared studies validated the expected synthesis of copolymers. Doxorubicin is chemically loaded into micelles, and the ex vitro release can be evaluated either in weak acidic or in SBF solution by UV-vis spectroscopy. Dynamic light scattering, thermo gravimetric analysis, and size exclusion chromatography have also been used.

  5. A Novel Active Targeting Preparation, Vinorelbine Tartrate (VLBT Encapsulated by Folate-Conjugated Bovine Serum Albumin (BSA Nanoparticles: Preparation, Characterization and in Vitro Release Study

    Directory of Open Access Journals (Sweden)

    Xinyang Yu

    2012-11-01

    Full Text Available Vinorelbine tartrate (VLBT, as a kind of high hydrophilic and temperature-induced degradation drug, was prepared into nanoparticles by a desolvation procedure. Bovine serum albumin (BSA, as a drug carrier, was stabilized by chemical cross-linking with glutaraldehyde. Firstly, the optimization process of preparing VLBT-loaded BSA nanoparticles (VLBT-BSANPs was accomplished using response surface methodology (RSM by desolvation. Then VLBT-BSANPs were conjugated with folate, namely Fa-BSANPs-VLBT. Hence targeting drug carrier delivery system loading VLBT was produced. In this study, the characteristics of the nanoparticles, such as the amount of folate conjugation, surface morphology, surface