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Sample records for acetate tightness test

  1. 42 CFR 84.1142 - Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts, fumes, and mists having an air contamination level less... dusts, fumes, and mists having an air contamination level less than 0.05 milligram per cubic meter,...

  2. 42 CFR 84.1142 - Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts, fumes, and mists having an air contamination level less... dusts, fumes, and mists having an air contamination level less than 0.05 milligram per cubic meter,...

  3. 42 CFR 84.1142 - Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts, fumes, and mists having an air contamination level less... dusts, fumes, and mists having an air contamination level less than 0.05 milligram per cubic meter,...

  4. 42 CFR 84.1142 - Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts, fumes, and mists having an air contamination level less... dusts, fumes, and mists having an air contamination level less than 0.05 milligram per cubic meter,...

  5. 42 CFR 84.1142 - Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts, fumes, and mists having an air contamination level less... dusts, fumes, and mists having an air contamination level less than 0.05 milligram per cubic meter,...

  6. The potential utility of tight junction regulation in celiac disease: focus on larazotide acetate

    PubMed Central

    Khaleghi, Shahryar; Ju, Josephine M.; Lamba, Abhinav; Murray, Joseph A.

    2016-01-01

    Celiac disease (CD) is a common chronic immune disease triggered by gluten. Gliadin peptides pass through the epithelial layers, either paracellularly or transcellularly, to launch a potent adaptive immune response in the lamina propria. This aberrant immune response leads to diverse gastrointestinal and extra-gastrointestinal symptoms. Currently, the only treatment for CD is a strict lifelong adherence to a gluten-free diet (GFD), which can be challenging. An early effect of gluten in CD is an increase in gut permeability. Larazotide acetate, also known as AT-1001, is a synthetic peptide developed as a permeability regulator primarily targeting CD. In vitro studies indicate that larazotide acetate is capable of inhibiting the actin rearrangement caused by gliadin and clinical studies have been conducted using this peptide as a therapy for CD. PMID:26770266

  7. Functional effects of the antigen glatiramer acetate are complex and tightly associated with its composition.

    PubMed

    Hasson, Tal; Kolitz, Sarah; Towfic, Fadi; Laifenfeld, Daphna; Bakshi, Shlomo; Beriozkin, Olga; Shacham-Abramson, Maya; Timan, Bracha; Fowler, Kevin D; Birnberg, Tal; Konya, Attila; Komlosh, Arthur; Ladkani, David; Hayden, Michael R; Zeskind, Benjamin; Grossman, Iris

    2016-01-15

    Glatiramer acetate (Copaxone®; GA) is a non-biological complex drug for multiple sclerosis. GA modulated thousands of genes in genome-wide expression studies conducted in THP-1 cells and mouse splenocytes. Comparing GA with differently-manufactured glatiramoid Polimunol (Synthon) in mice yielded hundreds of differentially expressed probesets, including biologically-relevant genes (e.g. Il18, adj p<9e-6) and pathways. In human monocytes, 700+ probesets differed between Polimunol and GA, enriching for 130+ pathways including response to lipopolysaccharide (adj. p<0.006). Key differences were confirmed by qRT-PCR (splenocytes) or proteomics (THP-1). These studies demonstrate the complexity of GA's mechanisms of action, and may help inform therapeutic equivalence assessment. PMID:26711576

  8. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false 5-Hydroxyindole acetic acid/serotonin test system... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic...

  9. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic...

  10. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false 5-Hydroxyindole acetic acid/serotonin test system... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic...

  11. Adiabatic calorimetry (RSST and VSP) tests with sodium acetate

    SciTech Connect

    Kirch, N.W.

    1993-09-01

    As requested in the subject reference, adiabatic calorimetry (RSST and VSP) tests have been performed with sodium acetate covering TOC concentrations from 3 to 7% with the following results: Exothermic activity noted around 200{degrees}C. Propagating reaction initiated at about 300{degrees}C. Required TOC concentration for propagation estimated at about 6 w% (dry mixture) or about 20 w% sodium acetate. Heat of reaction estimated to be 3.7 MJ per kg of sodium acetate (based on VSP test with 3 w% TOC and using a dry mixture specific heat of 1000 J kg{sup {minus}1} K{sup {minus}1}). Based upon the above results we estimate that a moisture content in excess of 14 w% would prevent a propagating reaction of a stoichiometric mixture of fuel and oxidizer ({approximately} 38 w% sodium acetate and {approximately}62 w% sodium nitrate). Assuming that the fuel can be treated as sodium acetate equivalent, and considering that the moisture content in the organic containing waste generally is believed to be in excess of 14 w%, it follows that the possibility of propagating reactions in the Hanford waste tanks can be ruled out.

  12. Summary report for the tank tightness testing of underground storage tanks, Idaho National Engineering Laboratory

    SciTech Connect

    Not Available

    1990-03-01

    Between August 14, 1989, and August 26, 1989, 16 underground storage tanks were tank tightness tested for leaks as part of the Idaho National Engineering Laboratory tank management program. This report summarizes the results of these tank tightness tests, the modifications and repairs made to the tank systems, fuel transfer records, and any problems that affected the tank testing schedule. Of the 16 underground storage tanks tested, five failed the tank tightness test. Attempts were made to repair the tanks that failed the tank tightness test. Of those tanks, two were tested three times (one passed and one failed), and three were tested twice (two passed and one failed). The five failed tanks were removed and will be replaced with tanks that meet the Environmental Protection Agency regulations of underground storage tanks. 3 refs., 1 fig., 3 tabs.

  13. 42 CFR 84.104 - Gas tightness test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... apparatus is 2 hours. 2 Treadmill shall be inclined 15° from vertical and operated at a speed of 1 foot per... vertical and operated at a speed of 30 cm. (1 foot) per second. 2 Perform test No. 1 for...

  14. 42 CFR 84.104 - Gas tightness test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... apparatus is 2 hours. 2 Treadmill shall be inclined 15° from vertical and operated at a speed of 1 foot per... vertical and operated at a speed of 30 cm. (1 foot) per second. 2 Perform test No. 1 for...

  15. Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.

    ERIC Educational Resources Information Center

    Donahue, Craig J.; Panek, Mary G.

    1985-01-01

    Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

  16. Leak testing of bubble-tight dampers using tracer gas techniques

    SciTech Connect

    Lagus, P.L.; DuBois, L.J.; Fleming, K.M.

    1995-02-01

    Recently tracer gas techniques have been applied to the problem of measuring the leakage across an installed bubble-tight damper. A significant advantage of using a tracer gas technique is that quantitative leakage data are obtained under actual operating differential pressure conditions. Another advantage is that leakage data can be obtained using relatively simple test setups that utilize inexpensive materials without the need to tear ducts apart, fabricate expensive blank-off plates, and install test connections. Also, a tracer gas technique can be used to provide an accurate field evaluation of the performance of installed bubble-tight dampers on a periodic basis. Actual leakage flowrates were obtained at Zion Generating Station on four installed bubble-tight dampers using a tracer gas technique. Measured leakage rates ranged from 0.01 CFM to 21 CFM. After adjustment and subsequent retesting, the 21 CFM damper leakage was reduced to a leakage of 3.8 CFM. In light of the current regulatory climate and the interest in Control Room Habitability issues, imprecise estimates of critical air boundary leakage rates--such as through bubble-tight dampers--are not acceptable. These imprecise estimates can skew radioactive dose assessments as well as chemical contaminant exposure calculations. Using a tracer gas technique, the actual leakage rate can be determined. This knowledge eliminates a significant source of uncertainty in both radioactive dose and/or chemical exposure assessments.

  17. Relationship between Lower Extremity Tightness and Star Excursion Balance Test Performance in Junior High School Baseball Players.

    PubMed

    Endo, Yasuhiro; Sakamoto, Masaaki

    2014-05-01

    [Purpose] The purpose of this study was to examine the relationship between lower extremity tightness and lower extremity balance, measured by the Star Excursion Balance Test (SEBT), in junior high school baseball players. [Subjects] Thirty-three male students belonging to baseball clubs in 2 junior high schools participated in this study. [Methods] For the SEBT, we chose to examine the anterior (ANT), posterior (POS), lateral (LAT), and medial (MED) directions. Regarding muscle tightness measurement, the angle of each joint of the bilateral iliopsoas, quadriceps, hamstring, gastrocnemius, hip internal rotator, and hip external rotator was measured. [Results] The ANT direction of the SEBT was significantly negatively correlated with gastrocnemius tightness. The MED direction of the SEBT was significantly positively correlated with hip internal rotator tightness and hamstrings tightness and significantly negatively correlated with gastrocnemius tightness. The LAT direction of the SEBT was significantly negatively correlated with iliopsoas tightness and gastrocnemius tightness. [Conclusion] Since the rate of upper extremity injury is high in these subjects and this could be due to tightness and instability of the lower extremity from a kinetic viewpoint, the SEBT could be used as a standard evaluation test when examining upper extremity injuries in young baseball players. PMID:24926127

  18. Results of field verification tests in the Tight Mesaverde Group: Piceance Basin, Colorado

    SciTech Connect

    Kukal, G.C.; Price, E.H.; Hill, R.E.; Monson, E.R.

    1992-08-01

    The Piceance Basin of western Colorado contains a major potential natural gas resource in Mesaverde blanket and lenticular low permeability gas sands. The basin has been a pilot study area for government sponsored tight gas sand research for over 20 years. This work culminated in the Multiwell Experiment (MWX), a field laboratory consisting of three closely spaced wells, designed by the Department of Energy to study the reservoir and production characteristics of the low permeability sands of the Mesaverde Group in the Rulison Field near Rifle, Colorado. The purpose of this study is to compare geologic, production and reservoir characteristics of the existing Mesaverde producing areas in the Piceance Basin with those same characteristics at the Multiwell site. This study has been performed in two sequential parts, Phase I and Phase II. In Phase I the geologic, production and reservoir engineering parameters were developed for the existing Mesaverde gas producing areas through analysis of log suites, well completion information and production histories. The southern part of the basin was partitioned into three areas having similar geologic and production characteristics. Phase II consisted of field verification tests with cooperative industry partners in which new subsurface geologic and production information was collected in the partitioned areas to be compared with that at MWX. This report presents the results of Phase II investigations.

  19. Results of field verification tests in the Tight Mesaverde Group: Piceance Basin, Colorado. Final report

    SciTech Connect

    Kukal, G.C.; Price, E.H.; Hill, R.E.; Monson, E.R.

    1992-08-01

    The Piceance Basin of western Colorado contains a major potential natural gas resource in Mesaverde blanket and lenticular low permeability gas sands. The basin has been a pilot study area for government sponsored tight gas sand research for over 20 years. This work culminated in the Multiwell Experiment (MWX), a field laboratory consisting of three closely spaced wells, designed by the Department of Energy to study the reservoir and production characteristics of the low permeability sands of the Mesaverde Group in the Rulison Field near Rifle, Colorado. The purpose of this study is to compare geologic, production and reservoir characteristics of the existing Mesaverde producing areas in the Piceance Basin with those same characteristics at the Multiwell site. This study has been performed in two sequential parts, Phase I and Phase II. In Phase I the geologic, production and reservoir engineering parameters were developed for the existing Mesaverde gas producing areas through analysis of log suites, well completion information and production histories. The southern part of the basin was partitioned into three areas having similar geologic and production characteristics. Phase II consisted of field verification tests with cooperative industry partners in which new subsurface geologic and production information was collected in the partitioned areas to be compared with that at MWX. This report presents the results of Phase II investigations.

  20. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section 862.1390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1390...

  1. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section 862.1390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical...

  2. Development and testing of an ion probe for tightly-bunched particle beams

    SciTech Connect

    Ngo, M.; Pasour, J.

    1996-06-01

    Many high-energy physics experiments require a high-quality and well-diagnosed charged-particle beam (CPB). Precise knowledge of beam size, position, and charge distribution is often crucial to the success of the experiment. It is also important in many applications that the diagnostic used to determine the beam parameters be nonintercepting and nonperturbing. This requirement rules out many diagnostics, such as wire scanners, thin foils which produce Cerenkov or transition radiation, and even some rf cavity diagnostics. Particularly difficult to diagnose are tightly-focused (r{sub b} << 1 mm), short-duration (psec) beams, such as those in state-of-the-art or next-generation particle colliders. In this paper we describe an ion probe that is capable of penetrating the space-charge field of densely bunched CPBs without perturbation, thereby enabling the measurement of the microstructure of the bunch. This diagnostic probe uses a finely-focused stream of ions to interact with the CPB. Related techniques have been discussed in the literature. In fact, the present work evolved from an electron deflection diagnostic for CPBs that we previously described. A similar electron probe was tested even earlier at TRIUMF and in the Former Soviet Union. Electron probes have also been used to measure plasma sheaths and potentials and the neutralization of heavy ion beams. Also, Mendel has used an ion beam (22 keV He{sup +}) to probe rapidly varying fields in plasmas. The probe ions are injected across the beam tube and into the path of the high-energy CPB. The ions are deflected by the CPB, and the direction and magnitude of the deflection are directly related to the spatial and temporal charge distribution of the CPB. Easily-resolved deflections can be produced by microbunches having total charge on the order of a nCoul and pulse durations of a few psec. The deflected ions are monitored with a suitable detector, in this case a microchannel plate capable of detecting single ions.

  3. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  4. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  5. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  6. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  7. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  8. Tipepidine enhances the antinociceptive-like action of carbamazepine in the acetic acid writhing test.

    PubMed

    Kawaura, Kazuaki; Miki, Risa; Urashima, Yuri; Honda, Sokichi; Shehata, Ahmed M; Soeda, Fumio; Shirasaki, Tetsuya; Takahama, Kazuo

    2011-01-25

    Several antidepressants have been used to treat severe pain in clinics. Recently, we reported that the centrally acting non-narcotic antitussive (cough suppressant drug), tipepidine produces an antidepressant-like effect in the forced swimming test, although the mechanism of action appears to be quite different from that of known antidepressants. In the present study, we investigated whether a combination of tipepidine and carbamazepine acts synergistically to induce an antinociceptive effect in the acetic acid-induced writhing test in mice. Prior to studying the combination of tipepidine and carbamazepine, the analgesic action of tipepidine alone was also examined in mice. Tipepidine at 5-40mg/kg i.p. significantly reduced the number of writhes induced by acetic acid in mice. Carbamazepine at 20mg/kg i.p. also significantly reduced the writhing reaction. Furthermore, co-administration of carbamazepine (5 and 10mg/kg, i.p.) and tipepidine (2.5mg/kg i.p.) significantly decreased the number of writhes induced by acetic acid. This finding suggests that a combination of carbamazepine and tipepidine may be a new strategy for the treatment of neuropathic pain such as what occurs in trigeminal neuralgia, because the use of carbamazepine is often limited by its adverse effects and by reduction of its analgesic efficacy by microsomal enzyme induction. PMID:21114989

  9. Tight bag

    PubMed Central

    Parthasarathy, S; Ravishankar, M

    2010-01-01

    Tight bag is a clinical situation where excessive pressure needs to be applied to a reservoir bag of a breathing system to an intubated patient, which may or may not produce satisfactory ventilation. The various clinical scenarios and the appropriate steps for its prevention are described. PMID:20885863

  10. Detection of tightly closed flaws by nondestructive testing (NDT) methods in steel and titanium

    NASA Technical Reports Server (NTRS)

    Rummel, W. D.; Rathke, R. A.; Todd, P. H., Jr.; Tedrow, T. L.; Mullen, S. J.

    1976-01-01

    X-radiographic, liquid penetrant, ultrasonic, eddy current and magnetic particle testing techniques were optimized and applied to the evaluation of 4340 steel (180 KSI-UTS) and 6Al-4V titanium (STA) alloy specimens. Sixty steel specimens containing a total of 176 fatigue cracks and 60 titanium specimens containing a total of 135 fatigue cracks were evaluated. The cracks ranged in length from .043 cm (0.017 inch) to 1.02 cm (.400 inch) and in depth from .005 cm (.002 inch) to .239 cm (.094 inch) for steel specimens. Lengths ranged from .048 cm (0.019 inch) to 1.03 cm (.407 inch) and depths from 0.010 cm (.004 inch) to .261 cm (0.103 inch) for titanium specimens. Specimen thicknesses were nominally .152 cm (0.060 inch) and 0.635 cm (0.250 inch) and surface finishes were nominally 125 rms. Specimens were evaluated in the "as machined" surface condition, after etch surface and after proof loading in a randomized inspection sequence.

  11. The detection of tightly closed flaws by nondestructive testing (NDT) methods. [fatigue crack formation in aluminum alloy test specimens

    NASA Technical Reports Server (NTRS)

    Rummel, W. D.; Rathke, R. A.; Todd, P. H., Jr.; Mullen, S. J.

    1975-01-01

    Liquid penetrant, ultrasonic, eddy current and X-radiographic techniques were optimized and applied to the evaluation of 2219-T87 aluminum alloy test specimens in integrally stiffened panel, and weld panel configurations. Fatigue cracks in integrally stiffened panels, lack-of-fusion in weld panels, and fatigue cracks in weld panels were the flaw types used for evaluation. A 2319 aluminum alloy weld filler rod was used for all welding to produce the test specimens. Forty seven integrally stiffened panels containing a total of 146 fatigue cracks, ninety three lack-of-penetration (LOP) specimens containing a total of 239 LOP flaws, and one-hundred seventeen welded specimens containing a total of 293 fatigue cracks were evaluated. Nondestructive test detection reliability enhancement was evaluated during separate inspection sequences in the specimens in the 'as-machined or as-welded', post etched and post proof loaded conditions. Results of the nondestructive test evaluations were compared to the actual flaw size obtained by measurement of the fracture specimens after completing all inspection sequences. Inspection data were then analyzed to provide a statistical basis for determining the flaw detection reliability.

  12. Improvement of energy efficiency: the use of thermography and air-tightness test in verification of thermal performance of school buildings

    NASA Astrophysics Data System (ADS)

    Kauppinen, Timo; Siikanen, Sami

    2011-05-01

    The improvement of energy efficiency is the key issue after the energy performance of buildings directive came into the force in European Union countries. The city of Kuopio participate a project, in which different tools will be used, generated and tested to improve the energy efficiency of public buildings. In this project there are 2 schools, the other consuming much more heating energy than the other same type of school. In this paper the results of the thermography in normal conditions and under 50 Pa pressure drop will be presented; as well as the results of remote controlled air tightness test of the buildings. Thermography combined with air tightness test showed clearly the reasons of specific consumption differences of heating energy - also in the other hand, the measurements showed the problems in the performance of ventilation system. Thermography, air tightness test and other supporting measurements can be used together to solve energy loss problems - if these measurements will be carried out by proper way.

  13. Wear Characterization of Carbon Nanotubes Reinforced Acetal Spur, Helical, Bevel and Worm Gears Using a TS Universal Test Rig

    NASA Astrophysics Data System (ADS)

    Yousef, Samy; Osman, T. A.; Abdalla, Abdelrahman H.; Zohdy, Gamal A.

    2015-12-01

    Although the applications of nanotechnologies are increasing, there remains a significant barrier between nanotechnology and machine element applications. This work aims to remove this barrier by blending carbon nanotubes (CNT) with common types of acetal polymer gears (spur, helical, bevel and worm). This was done by using adhesive oil (paraffin) during injection molding to synthesize a flange and short bars containing 0.02% CNT by weight. The flanges and short bars were machined using hobbing and milling machines to produce nanocomposite polymer gears. Some defects that surfaced in previous work, such as the appearance of bubbles and unmelted pellets during the injection process, were avoided to produce an excellent dispersion of CNT in the acetal. The wear resistances of the gears were measured by using a TS universal test rig using constant parameters for all of the gears that were fabricated. The tests were run at a speed of 1420 rpm and a torque of 4 Nm. The results showed that the wear resistances of the CNT/acetal gears were increased due to the addition of CNT, especially the helical, bevel and worm gears.

  14. Utilization of d-tartaric acid by Salmonella paratyphi B and Salmonella java: comparison of anaerobic plate test, lead acetate test and turbidity test.

    PubMed Central

    Barker, R. M.

    1985-01-01

    d-Tartrate dehydrase of Salmonella java is an oxygen-sensitive enzyme active in cultures incubated under the poorly aerated conditions of static culture but not in fully aerated shaken cultures nor on plates incubated aerobically. On plates of d-tartrate minimal agar incubated anaerobically the enzyme or the degradation products of d-tartrate are exported from d-tartrate-positive cells and are available to d-tartrate-negative bacteria. This may give misleading growth results when d-tartrate-positive and d-tartrate-negative strains are tested for growth on the same plate of d-tartrate minimal agar. The lead-acetate test terminated at 24 h, the 24 h turbidity test and the ability to grow on d-tartrate minimal agar within 48 h differentiated 53 S. paratyphi B strains that were negative in each of the three tests from 76 S. java that were positive in each of the tests. An intermediate group of eight strains utilized d-tartrate in Difco bacto-peptone water to give a positive lead acetate reaction at 2 days, were stimulated to a varying degree by d-tartrate in Oxoid peptone water within the same period of incubation and grew poorly on d-tartrate minimal agar. These latter strains may be deficient in a permease controlling uptake of d-tartrate or export of d-tartrate dehydrase. Inability to utilize d-tartrate is unlikely to be the single character accountable for the reputed enhanced pathogenicity of S. paratyphi B when compared with S. java. Indications for the existence of an enzyme, complementary to and mutually exclusive with d-tartrate dehydrase, that has a positive correlation with pathogenicity are discussed. PMID:3894507

  15. Suitability of the methylene blue test for determination of cation exchange capacity of clay minerals related to ammonium acetate method

    NASA Astrophysics Data System (ADS)

    Milošević, Maja; Logar, Mihovil; Dojčinović, Biljana; Erić, Suzana

    2015-04-01

    Cation exchange capacity (CEC) represents one of the most important parameters of clay minerals which reflects their ability to exchange cations with liquid phases in near contact. Measurement of CEC is used for characterizing sample plasticity, adsorbing and swelling properties which later define their usage in industrial purposes. Several methods have been developed over the years for determination of layer charge, charge density, charge distribution, etc. and have been published in numerous papers (Czimerova et al., 2006; Yukselen and Kaya, 2008). The main goal of present study is comparison of suitability of more recent method - methylene blue test in regard to older method - ammonium acetate for determination of CEC. For this study, we selected one montmorillonite clay (Bogovina, Serbia) and two mainly kaolinite clays (Miličinica, Serbia). Chemicals used for CEC determinations were solution of methylene blue (MB)(14*10-6M/ml) and ammonium acetate (AA) solution (1M). The obtained results are showing generally lower values in case of MB method. The main difference is due to molecular aggregation of MB on the clay surface. AA method is highly sensitive to the presence of CaO. Release of Ca ion from the sample into the solution can limit the saturation of exchange sites by the ammonium ion. This is clearly visible in case of montmorillonite clay. Fe2+ and Mg ions are difficult to move by the ammonium ion because of their ion radius, but in case of MB molecule there is no such restriction in removing them from the exchange sites. MB solution, even in a low concentration (2*10-6M/ml), is showing preferable results in moving the ions from their positions which is already visible after adding a small quantity of solution (25cm3). Both MB-titration and MB-spot test yield similar results and are much simpler methods than AA and they also give other information such as specific surface area (external and internal) whereas AA method only provides information about

  16. First European Report of Social Wasps Trapped in Response to Acetic acid, Isobutanol, 2-Methyl-2-propanol, and Heptyl butyrate in Tests Conducted in Hungary

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five species of social wasps were captured in trapping tests in Hungary that evaluated the attractiveness of acetic acid, isobutanol, 2-methyl-2-propanol, and heptyl butyrate to social wasps. Both Vespula vulgaris (L.) and Vespula germanica (Fabr.), were captured in traps baited with isobutanol, t...

  17. Tight Diabetes Control

    MedlinePlus

    ... Size: A A A Listen En Español Tight Diabetes Control Keeping your blood glucose levels as close ... and syringes, than before. What About Type 2 Diabetes? The DCCT studied only people with type 1 ...

  18. Ammonium acetate

    Integrated Risk Information System (IRIS)

    Ammonium acetate ; CASRN 631 - 61 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  19. Vinyl acetate

    Integrated Risk Information System (IRIS)

    Vinyl acetate ; CASRN 108 - 05 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  20. Ethyl acetate

    Integrated Risk Information System (IRIS)

    Ethyl acetate ; CASRN 141 - 78 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  1. Phenylmercuric acetate

    Integrated Risk Information System (IRIS)

    Phenylmercuric acetate ; CASRN 62 - 38 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  2. Thallium acetate

    Integrated Risk Information System (IRIS)

    Jump to main content . Integrated Risk Information System Recent Additions | Contact Us Search : All EPA IRIS • You are here : EPA Home • Research • Environmental Assessment • IRIS • IRIS Summaries Redirect Page As of September 30 , 2009 , the assessment summary for Thallium acetate is included in t

  3. Complex equiangular tight frames

    NASA Astrophysics Data System (ADS)

    Tropp, Joel A.

    2005-08-01

    A complex equiangular tight frame (ETF) is a tight frame consisting of N unit vectors in Cd whose absolute inner products are identical. One may view complex ETFs as a natural geometric generalization of an orthonormal basis. Numerical evidence suggests that these objects do not arise for most pairs (d, N). The goal of this paper is to develop conditions on (d, N) under which complex ETFs can exist. In particular, this work concentrates on the class of harmonic ETFs, in which the components of the frame vectors are roots of unity. In this case, it is possible to leverage field theory to obtain stringent restrictions on the possible values for (d, N).

  4. Tight bifunctional hierarchical catalyst.

    PubMed

    Højholt, Karen T; Vennestrøm, Peter N R; Tiruvalam, Ramchandra; Beato, Pablo

    2011-12-28

    A new concept to prepare tight bifunctional catalysts has been developed, by anchoring CoMo(6) clusters on hierarchical ZSM-5 zeolites for simultaneous use in HDS and hydrocracking catalysis. The prepared material displays a significant improved activity in HDS catalysis compared to the impregnated counterpart. PMID:22048337

  5. Air tightness of buildings in Finland

    NASA Astrophysics Data System (ADS)

    Kauppinen, Timo T.

    2001-03-01

    There are no requirements of building air tightness in Finland. Buildings always have thermal bridges and air leak routes, whose impact in decreasing comfort depends on the structures and the way of constructing. Uncontrolled air leaks are cooling the structures and causing draft and, in the long run, defects. These air leaks and thermal bridges can be found only by thermal scanning. In Finland building air tightness has been measured for over 20 years. The procedure includes two stages, in which the target is scanned by a thermal imager. The paper is based on the results of over 200 tests of one-family and detached houses. The air tightness level has improved, but there are still problems in the structural details. The monitoring procedure for therm scanning of buildings should be further developed (there is no generally accepted practice at the moment), as well as air tightness requirements should be created.

  6. Agreement of the Kato-Katz test established by the WHO with samples fixed with sodium acetate analyzed at 6 months to diagnose intestinal geohelminthes.

    PubMed

    Alfredo Fernández-Niño, Julián; David Ramírez, Juan; Consuelo López, Myriam; Inés Moncada, Ligia; Reyes, Patricia; Darío Heredia, Rubén

    2015-06-01

    The aim of this study was to evaluate the performance of the Kato-Katz test (WHO version) with stool samples from a rural area, fixed with sodium acetate (SAF). The Kato-Katz test was used to compare unfixed samples (conventional test) with the same samples containing SAF fixative at time 0 and at 6 months. The study included stools from 154 subjects. A marginally statistically significant decrease in prevalence was estimated only for hookworm, when comparing unfixed samples versus the SAF fixed samples read at 6 months (p=0.06). A significant reduction in parasite load was found for hookworm (p<0.01) and Trichuris trichiura (p<0.01) between the unfixed and the fixed sample read at 6 months, but not for Ascaris lumbricoides (p=0.10). This research suggests that the SAF fixative solution is a good option for transporting samples for diagnosis, especially in rural areas in developing countries. PMID:25771113

  7. Antibiofilm Properties of Acetic Acid

    PubMed Central

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup; Nielsen, Anne K.; Johansen, Helle Krogh; Homøe, Preben; Høiby, Niels; Givskov, Michael; Kirketerp-Møller, Klaus

    2015-01-01

    Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms. PMID:26155378

  8. Tight Junctions Go Viral!

    PubMed Central

    Torres-Flores, Jesús M.; Arias, Carlos F.

    2015-01-01

    Tight junctions (TJs) are highly specialized membrane domains involved in many important cellular processes such as the regulation of the passage of ions and macromolecules across the paracellular space and the establishment of cell polarity in epithelial cells. Over the past few years there has been increasing evidence that different components of the TJs can be hijacked by viruses in order to complete their infectious cycle. Viruses from at least nine different families of DNA and RNA viruses have been reported to use TJ proteins in their benefit. For example, TJ proteins such as JAM-A or some members of the claudin family of proteins are used by members of the Reoviridae family and hepatitis C virus as receptors or co-receptors during their entry into their host cells. Reovirus, in addition, takes advantage of the TJ protein Junction Adhesion Molecule-A (JAM-A) to achieve its hematogenous dissemination. Some other viruses are capable of regulating the expression or the localization of TJ proteins to induce cell transformation or to improve the efficiency of their exit process. This review encompasses the importance of TJs for viral entry, replication, dissemination, and egress, and makes a clear statement of the importance of studying these proteins to gain a better understanding of the replication strategies used by viruses that infect epithelial and/or endothelial cells. PMID:26404354

  9. Keeping Schools Safe during Tight Budget Times

    ERIC Educational Resources Information Center

    Trump, Kenneth S.

    2010-01-01

    Tight budgets are no excuse for failing to be proactive with school safety. In fact, school leaders must be especially committed to prevention and security programs during times when economic woes are increasing stress on kids, their families and school staff. Parents will forgive educators if their school's test scores drop. But they are much…

  10. Design and Performance Testing of a DNA Extraction Assay for Sensitive and Reliable Quantification of Acetic Acid Bacteria Directly in Red Wine Using Real Time PCR.

    PubMed

    Longin, Cédric; Guilloux-Benatier, Michèle; Alexandre, Hervé

    2016-01-01

    Although strategies exist to prevent AAB contamination, the increased interest for wines with low sulfite addition leads to greater AAB spoilage. Hence, there is a real need for a rapid, specific, sensitive, and reliable method for detecting these spoilage bacteria. All these requirements are met by real time Polymerase Chain Reaction (or quantitative PCR; qPCR). Here, we compare existing methods of isolating DNA and their adaptation to a red wine matrix. Two different protocols for isolating DNA and three PCR mix compositions were tested to select the best method. The addition of insoluble polyvinylpolypyrrolidone (PVPP) at 1% (v/v) during DNA extraction using a protocol succeeded in eliminating PCR inhibitors from red wine. We developed a bacterial internal control which was efficient in avoiding false negative results due to decreases in the efficiency of DNA isolation and/or amplification. The specificity, linearity, repeatability, and reproducibility of the method were evaluated. A standard curve was established for the enumeration of AAB inoculated into red wines. The limit of quantification in red wine was 3.7 log AAB/mL and about 2.8 log AAB/mL when the volume of the samples was increased from 1 to 10 mL. Thus, the DNA extraction method developed in this paper allows sensitive and reliable AAB quantification without underestimation thanks to the presence of an internal control. Moreover, monitoring of both the AAB population and the amount of acetic acid in ethanol medium and red wine highlighted that a minimum about 6.0 log cells/mL of AAB is needed to significantly increase the production of acetic acid leading to spoilage. PMID:27313572

  11. Design and Performance Testing of a DNA Extraction Assay for Sensitive and Reliable Quantification of Acetic Acid Bacteria Directly in Red Wine Using Real Time PCR

    PubMed Central

    Longin, Cédric; Guilloux-Benatier, Michèle; Alexandre, Hervé

    2016-01-01

    Although strategies exist to prevent AAB contamination, the increased interest for wines with low sulfite addition leads to greater AAB spoilage. Hence, there is a real need for a rapid, specific, sensitive, and reliable method for detecting these spoilage bacteria. All these requirements are met by real time Polymerase Chain Reaction (or quantitative PCR; qPCR). Here, we compare existing methods of isolating DNA and their adaptation to a red wine matrix. Two different protocols for isolating DNA and three PCR mix compositions were tested to select the best method. The addition of insoluble polyvinylpolypyrrolidone (PVPP) at 1% (v/v) during DNA extraction using a protocol succeeded in eliminating PCR inhibitors from red wine. We developed a bacterial internal control which was efficient in avoiding false negative results due to decreases in the efficiency of DNA isolation and/or amplification. The specificity, linearity, repeatability, and reproducibility of the method were evaluated. A standard curve was established for the enumeration of AAB inoculated into red wines. The limit of quantification in red wine was 3.7 log AAB/mL and about 2.8 log AAB/mL when the volume of the samples was increased from 1 to 10 mL. Thus, the DNA extraction method developed in this paper allows sensitive and reliable AAB quantification without underestimation thanks to the presence of an internal control. Moreover, monitoring of both the AAB population and the amount of acetic acid in ethanol medium and red wine highlighted that a minimum about 6.0 log cells/mL of AAB is needed to significantly increase the production of acetic acid leading to spoilage. PMID:27313572

  12. Effect of acetate upon the formation of acetoin in Klebsiella and Enterobacter and it possible practical application in a rapid voges-proskauer test.

    PubMed

    Bryn, K; Ulstrup, J C; Stormer, F C

    1973-03-01

    Acetate stimulates the formation of acetoin during 1-h incubation of Voges-Proskauer-positive strains of Klebsiella and Enterobacter. Of these organisms, 124 of 126 strains were recognized as positive in the presence of acetate, and 106 were recognized as positive in its absence. PMID:4572901

  13. Behavioural Effects of the Commonly Used Fish Anaesthetic Tricaine Methanesulfonate (MS-222) on Zebrafish (Danio rerio) and Its Relevance for the Acetic Acid Pain Test

    PubMed Central

    Nordgreen, Janicke; Tahamtani, Fernanda M.; Janczak, Andrew M.; Horsberg, Tor Einar

    2014-01-01

    The pros and cons of using anaesthesia when handling fish in connection with experiments are debated. A widely adopted practice is to wait thirty minutes after anaesthesia before behavioural observations are initiated, but information about immediate effects of a treatment is then lost. This is pertinent for responses to acute stressors, such as acid injection in the acetic acid pain test. However, omission of anaesthetics in order to obtain data on immediate responses will compromise the welfare of fish and contribute to experimental noise due to stress. We therefore tested the effect of tricaine methanesulfonate on the behaviour of zebrafish. We predicted that tricaine (MS 222) would decrease swimming velocity and that the control fish would show an increased level of anxiety- and stress-related behaviours compared to the tricaine group. Following acclimatization to the test tank, baseline behaviour was recorded before immersion in either tricaine (168 mg l−1, treatment group, N = 8) or tank water (control group, N = 7). Latencies to lose equilibrium and to lose response to touch were registered. The fish was then returned to the test tank, and the latency to regain equilibrium was registered in anaesthetized fish. When equilibrium was regained, and at five, thirty and sixty minutes after the fish had been returned to the test tank, behaviour was recorded. The tricaine fish showed the following responses (mean ± sd): latency to lose equilibrium 22.6 s±3.9; latency to lose response to touch 101.9 s±26.8; latency to regain equilibrium 92.0 s±54.4. Contrary to our predictions, neither treatment caused a change in any of the behaviours registered. This indicates that tricaine has no effect on several commonly used behavioural parameters, and that it may be unnecessary to postpone behavioural observations to 30 min after anaesthesia. PMID:24658262

  14. Tuberculin Skin Test Negativity Is Under Tight Genetic Control of Chromosomal Region 11p14-15 in Settings With Different Tuberculosis Endemicities

    PubMed Central

    Cobat, Aurélie; Poirier, Christine; Hoal, Eileen; Boland-Auge, Anne; de La Rocque, France; Corrard, François; Grange, Ghislain; Migaud, Mélanie; Bustamante, Jacinta; Boisson-Dupuis, Stéphanie; Casanova, Jean-Laurent; Schurr, Erwin; Alcaïs, Alexandre; Delacourt, Christophe; Abel, Laurent

    2015-01-01

    A substantial proportion of subjects exposed to a contagious tuberculosis case display lack of tuberculin skin test (TST) reactivity. We previously mapped a major locus (TST1) controlling lack of TST reactivity in families from an area in South Africa where tuberculosis is hyperendemic. Here, we conducted a household tuberculosis contact study in a French area where the endemicity of tuberculosis is low. A genome-wide analysis of TST negativity identified a significant linkage signal (P < 3 × 10−5) in close vicinity of TST1. Combined analysis of the 2 samples increased evidence of linkage (P = 2.4 × 10−6), further implicating genetic factors located on 11p14-15. This region overlaps the TNF1 locus controlling mycobacteria-driven tumor necrosis factor α production. PMID:25143445

  15. Lead acetate does not inhibit dimethylnitrosamine activation and interacts with phenobarbital which is genotoxic in the ST cross of the Drosophila wing spot test.

    PubMed

    Castañeda-Partida, Laura; Heres-Pulido, Ma Eugenia; Guzmán-Rincón, Judith; Hernández-Portilla, Luis Barbo; Dueñas-García, Irma Elena; Durán-Díaz, Angel; Delfín-Alcalá, Irma

    2011-09-01

    Lead acetate (PbAc) is known to inhibit the synthesis of the heme group, needed for hemeproteins like Cytochromes P450 (CYP450s). Dimethylnitrosamine (DMN) requires metabolic activation by CYP450s. The Drosophila wing spot test was performed to establish whether PbAc inhibits DMN activation in the standard (ST) and high bioactivation (HB) crosses, with different levels of CYP450s. Phenobarbital (PH) was used as an antagonist for its ability to induce CYP450s synthesis. PbAc (0.01, 0.1, 1.0mM) produced significant small spots frequencies in the ST cross, indicating a possible genotoxic activity, however, the total spots frequency was negative at all concentrations. DMN (0.076 mM) was genotoxic in both crosses; surprisingly, PH (12 mM) was genotoxic and the PH-DMN treatment resulted synergic in the ST cross. Interestingly, the PbAc-PH pre-co-treatments showed a possible interaction in the ST cross. The GC-MS analysis showed a drop in the PH content as the PbAc concentration increased. PbAc also seemed to inhibit the genotoxic activity of PH, except at 0.01 mM. It is concluded that PbAc does not inhibit DMN activation by CYP450s in both crosses since it exerted a clear genotoxicity and that PH is genotoxic and interacts with PbAc in the ST but not the HB cross. PMID:21672598

  16. Testing zinc chloride as a new catalyst for direct synthesis of cellulose di- and tri-acetate in a solvent free system under microwave irradiation.

    PubMed

    El Nemr, Ahmed; Ragab, Safaa; El Sikaily, Amany

    2016-10-20

    This research demonstrates the effect of ZnCl2 as a catalyst on the esterification of commercial cotton cellulose using acetic anhydride in order to obtain di- and tri-cellulose acetates under microwave irradiation. It was discovered that microwave irradiation significantly increased the yield and reduced the reaction time. It was found that the maximum yield for cellulose triacetates was 95.83% under the reaction conditions that were as follows: 3min reaction time, 200mg of ZnCl2 catalyst and 20ml of Ac2O for 5g cellulose. However, the cellulose acetate obtained in this manner had the highest DS (2.87). The cellulose di-acetate was produced with the maximum yield of 89.97% and with the highest DS (2.69) using 25ml Ac2O, 200mg of ZnCl2 for 5g cellulose and in 3min reaction time. The effect of some factors such as the amount of used catalyst, the quantity of acetic acid anhydride and the reaction time of the esterification process have been investigated. The production of di- and tri-cellulose acetate and the degree of substitution were confirmed using Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR). The thermal stability was investigated using thermo gravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The molecular weight and the degree of polymerization were obtained using Gel Permeation Chromatography (GPC). The analysis confirmed the successful synthesis of di- and tri-cellulose acetate without degradation during the reaction; these results were found to be in contrast to some recent studies. The present study reveals that ZnCl2 is a new catalyst; it is effective as well as inexpensive and is a low toxicity catalyst for usage in cellulose esterification. PMID:27474655

  17. Preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  18. Preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-03-24

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  19. Strengthening of the intestinal epithelial tight junction by Bifidobacterium bifidum

    PubMed Central

    Hsieh, Chen-Yu; Osaka, Toshifumi; Moriyama, Eri; Date, Yasuhiro; Kikuchi, Jun; Tsuneda, Satoshi

    2015-01-01

    Epithelial barrier dysfunction has been implicated as one of the major contributors to the pathogenesis of inflammatory bowel disease. The increase in intestinal permeability allows the translocation of luminal antigens across the intestinal epithelium, leading to the exacerbation of colitis. Thus, therapies targeted at specifically restoring tight junction barrier function are thought to have great potential as an alternative or supplement to immunology-based therapies. In this study, we screened Bifidobacterium, Enterococcus, and Lactobacillus species for beneficial microbes to strengthen the intestinal epithelial barrier, using the human intestinal epithelial cell line (Caco-2) in an in vitro assay. Some Bifidobacterium and Lactobacillus species prevented epithelial barrier disruption induced by TNF-α, as assessed by measuring the transepithelial electrical resistance (TER). Furthermore, live Bifidobacterium species promoted wound repair in Caco-2 cell monolayers treated with TNF-α for 48 h. Time course 1H-NMR-based metabonomics of the culture supernatant revealed markedly enhanced production of acetate after 12 hours of coincubation of B. bifidum and Caco-2. An increase in TER was observed by the administration of acetate to TNF-α-treated Caco-2 monolayers. Interestingly, acetate-induced TER-enhancing effect in the coculture of B. bifidum and Caco-2 cells depends on the differentiation stage of the intestinal epithelial cells. These results suggest that Bifidobacterium species enhance intestinal epithelial barrier function via metabolites such as acetate. PMID:25780093

  20. Pirbuterol Acetate Oral Inhalation

    MedlinePlus

    ... used to prevent and treat wheezing, shortness of breath, coughing, and chest tightness caused by asthma, chronic ... the puff; continue to take a full, deep breath. Take the inhaler away from you mouth, hold ...

  1. Diagnosing the tight building syndrome.

    PubMed Central

    Rogers, S A

    1987-01-01

    Formaldehyde is but one of many chemicals capable of causing the tight building syndrome or environmentally induced illness (EI). The spectrum of symptoms it may induce includes attacks of headache, flushing, laryngitis, dizziness, nausea, extreme weakness, arthralgia, unwarranted depression, dysphonia, exhaustion, inability to think clearly, arrhythmia or muscle spasms. The nonspecificity of such symptoms can baffle physicians from many specialties. Presented herein is a simple office method for demonstrating that formaldehyde is among the etiologic agents triggering these symptoms. The very symptoms that patients complain of can be provoked within minutes, and subsequently abolished, with an intradermal injection of the appropriate strength of formaldehyde. This injection aids in convincing the patient of the cause of the symptoms so he can initiate measures to bring his disease under control. PMID:3447898

  2. Diagnosing the tight building syndrome

    SciTech Connect

    Rogers, S.A.

    1987-12-01

    Formaldehyde is but one of many chemicals capable of causing the tight building syndrome or environmentally induced illness (EI). The spectrum of symptoms it may induce includes attacks of headache, flushing, laryngitis, dizziness, nausea, extreme weakness, arthralgia, unwarranted depression, dysphonia, exhaustion, inability to think clearly, arrhythmia or muscle spasms. The nonspecificity of such symptoms can baffle physicians from many specialties. Presented herein is a simple office method for demonstrating that formaldehyde is among the etiologic agents triggering these symptoms. The very symptoms that patients complain of can be provoked within minutes, and subsequently abolished, with an intradermal injection of the appropriate strength of formaldehyde. This injection aids in convincing the patient of the cause of the symptoms so he can initiate measure to bring his disease under control.

  3. Historical development of tight formation gas

    SciTech Connect

    Rosenberg, J.I.; Haas, M.R.

    1986-01-01

    The unproven recoverable resource base of tight gas, irrespective of technology or price, was estimated by the National Petroleum Council (NPC) to be on the order of 600 Tcf as of the beginning of 1980. The NPC also estimated an additional 12 Tcf of proven tight gas reserves in the lower-48 states. Gas Research Institute (GRI) has supported the creation of a tight gas production data base to update the NPC study and to assess the historical development of this resource and its implications for future recovery. The major findings of this study include the following points: (1) total tight gas production almost doubled over the period from 1970 through 1981, reaching a peak of 1.4 Tcf, or about 9% of total nonassociated gas production. Declining production activity among many gas sources since then has reduced the annual contribution of tight gas to between 1.0 and 1.2 Tcf in 1984; (2) the tight gas resource is substantially intermingled with higher permeability formations and, as compared with non-tight gas resources, is much less often found as a result of new exploration activity; (3) the size distribution of tight gas fields is skewed more toward smaller field sizes than are the distributions of mixed fields (i.e., including production from tight and non-tight formations) or exclusively non-tight fields; (4) between 17 and 27 Tcf of proved reserves were estimated to remain as of the beginning of 1983 from previously discovered tight gas fields in three Rocky Mountains states (Colorado, Wyoming, and Utah), much of Texas, and the San Juan basin (mainly western New Mexico). The Appalachian basin includes another 3 to 4 Tcf of remaining tight gas reserves. Total tight gas reserves represent up to half of the nonassociated gas reserves estimated to remain in the above areas. 9 references.

  4. Air tightness monitoring by IR thermography

    NASA Astrophysics Data System (ADS)

    Grinzato, Ermanno G.; Marinetti, Sergio; Bison, Paolo G.

    2004-04-01

    The standard air tightness test of containers is based on measurement of global parameters as the outlet of a specific gas, detected by specialised mass spectrometers. The identification and location of air leakages is extremely important especially for the container manufacturer. At the same time, the measure of the mass flux is of importance. IR Thermography has been successfully applied for leakages detection on buildings, but unfortunately, the noise due to The standard air tightness test of containers is based on measurement of global parameters as the outlet of a specific gas, detected by specialised mass spectrometers. The identification and location of air leakages is extremely important especially for the container manufacturer. At the same time, the measure of the mass flux is of importance. IR Thermography has been successfully applied for leakage detection on buildings, but unfortunately, the noise due to environment limits its applicability, particularly in case of a small flux. A new thermal procedure has been developed for the leakage detection. The technique is based on the stimulation of the envelope with a low oscillating heat flux and lock-in analysis. An airflow is injected, with a harmonically varying flowrate and a slightly higher temperature than the ambient. Then, the thermograms sequence is analyzed in the frequency domain. A review of quantitative techniques for the convective heat exchange measurement is reported. The procedure has been utilized for special containers used for both transport and exhibition of pictures inside museums. Tests performed before and after gaskets improvements show the capability of the technique to estimate qualitatively the airflow.

  5. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    1998-11-30

    The work plan for October 1, 1997 to September 30, 1998 consisted of investigation of a number of topical areas. These topical areas were reported in four quarterly status reports, which were submitted to DOE earlier. These topical areas are reviewed in this volume. The topical areas covered during the year were: (1) Development of preliminary tests of a production method for determining areas of natural fracturing. Advanced Resources has demonstrated that such a relationship exists in the southern Piceance basin tight gas play. Natural fracture clusters are genetically related to stress concentrations (also called stress perturbations) associated with local deformation such a faulting. The mechanical explanation of this phenomenon is that deformation generally initiates at regions where the local stress field is elevated beyond the regional. (2) Regional structural and geologic analysis of the Greater Green River Basin (GGRB). Application of techniques developed and demonstrated during earlier phases of the project for sweet-spot delineation were demonstrated in a relatively new and underexplored play: tight gas from continuous-typeUpper Cretaceous reservoirs of the Greater Green River Basin (GGRB). The effort included data acquisition/processing, base map generation, geophysical and remote sensing analysis and the integration of these data and analyses. (3) Examination of the Table Rock field area in the northern Washakie Basin of the Greater Green River Basin. This effort was performed in support of Union Pacific Resources- and DOE-planned horizontal drilling efforts. The effort comprised acquisition of necessary seismic data and depth-conversion, mapping of major fault geometry, and analysis of displacement vectors, and the development of the natural fracture prediction. (4) Greater Green River Basin Partitioning. Building on fundamental fracture characterization work and prior work performed under this contract, namely structural analysis using satellite and

  6. Acetate Dependence of Tumors

    PubMed Central

    Comerford, Sarah A.; Huang, Zhiguang; Du, Xinlin; Wang, Yun; Cai, Ling; Witkiewicz, Agnes; Walters, Holly; Tantawy, Mohammed N.; Fu, Allie; Manning, H. Charles; Horton, Jay D.; Hammer, Robert E.; McKnight, Steven L.; Tu, Benjamin P.

    2014-01-01

    SUMMARY Acetyl-CoA represents a central node of carbon metabolism that plays a key role in bioenergetics, cell proliferation and the regulation of gene expression. How highly glycolytic or hypoxic tumors are able to produce sufficient quantities of this metabolite to support cell growth and survival under nutrient-limiting conditions remains poorly understood. Here we show that the nucleocytosolic acetyl-CoA synthetase enzyme, ACSS2, supplies a key source of acetyl-CoA for tumors by capturing acetate as a carbon source. Despite exhibiting no gross deficits in growth or development, adult mice lacking ACSS2 exhibit a significant reduction in tumor burden in two different models of hepatocellular carcinoma. ACSS2 is expressed in a large proportion of human tumors and its activity is responsible for the majority of cellular acetate uptake into both lipids and histones. These observations may qualify ACSS2 as a targetable metabolic vulnerability of a wide spectrum of tumors. PMID:25525877

  7. Advanced Colloids Experiment (ACE-T1)

    NASA Technical Reports Server (NTRS)

    Meyer, William V.; Sicker, Ron; Brown, Dan; Eustace, John

    2015-01-01

    Increment 45 - 46 Science Symposium presentation of Advanced Colloids Experiment (ACE-T1) to RPO. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators.

  8. Heat Bonding of Irradiated Ethylene Vinyl Acetate

    NASA Technical Reports Server (NTRS)

    Slack, D. H.

    1986-01-01

    Reliable method now available for joining parts of this difficult-tobond material. Heating fixture encircles ethylene vinyl acetate multiplesocket part, providing heat to it and to tubes inserted in it. Fixtures specially designed to match parts to be bonded. Tube-and-socket bonds made with this technique subjected to tensile tests. Bond strengths of 50 percent that of base material obtained consistently.

  9. Advanced Hydraulic Fracturing Technology for Unconventional Tight Gas Reservoirs

    SciTech Connect

    Stephen Holditch; A. Daniel Hill; D. Zhu

    2007-06-19

    The objectives of this project are to develop and test new techniques for creating extensive, conductive hydraulic fractures in unconventional tight gas reservoirs by statistically assessing the productivity achieved in hundreds of field treatments with a variety of current fracturing practices ranging from 'water fracs' to conventional gel fracture treatments; by laboratory measurements of the conductivity created with high rate proppant fracturing using an entirely new conductivity test - the 'dynamic fracture conductivity test'; and by developing design models to implement the optimal fracture treatments determined from the field assessment and the laboratory measurements. One of the tasks of this project is to create an 'advisor' or expert system for completion, production and stimulation of tight gas reservoirs. A central part of this study is an extensive survey of the productivity of hundreds of tight gas wells that have been hydraulically fractured. We have been doing an extensive literature search of the SPE eLibrary, DOE, Gas Technology Institute (GTI), Bureau of Economic Geology and IHS Energy, for publicly available technical reports about procedures of drilling, completion and production of the tight gas wells. We have downloaded numerous papers and read and summarized the information to build a database that will contain field treatment data, organized by geographic location, and hydraulic fracture treatment design data, organized by the treatment type. We have conducted experimental study on 'dynamic fracture conductivity' created when proppant slurries are pumped into hydraulic fractures in tight gas sands. Unlike conventional fracture conductivity tests in which proppant is loaded into the fracture artificially; we pump proppant/frac fluid slurries into a fracture cell, dynamically placing the proppant just as it occurs in the field. From such tests, we expect to gain new insights into some of the critical issues in tight gas fracturing, in

  10. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  11. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  12. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  13. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  14. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  15. Exercise regulation of intestinal tight junction proteins.

    PubMed

    Zuhl, Micah; Schneider, Suzanne; Lanphere, Katherine; Conn, Carole; Dokladny, Karol; Moseley, Pope

    2014-06-01

    Gastrointestinal distress, such as diarrhoea, cramping, vomiting, nausea and gastric pain are common among athletes during training and competition. The mechanisms that cause these symptoms are not fully understood. The stress of heat and oxidative damage during exercise causes disruption to intestinal epithelial cell tight junction proteins resulting in increased permeability to luminal endotoxins. The endotoxin moves into the blood stream leading to a systemic immune response. Tight junction integrity is altered by the phosphoylation state of the proteins occludin and claudins, and may be regulated by the type of exercise performed. Prolonged exercise and high-intensity exercise lead to an increase in key phosphorylation enzymes that ultimately cause tight junction dysfunction, but the mechanisms are different. The purpose of this review is to (1) explain the function and physiology of tight junction regulation, (2) discuss the effects of prolonged and high-intensity exercise on tight junction permeability leading to gastrointestinal distress and (3) review agents that may increase or decrease tight junction integrity during exercise. PMID:23134759

  16. [Nomegestrol acetate: clinical pharmacology].

    PubMed

    Lello, S

    2009-10-01

    Progestogens are used in clinical practice in some conditions. Their effects depend on their chemical structure, pharmacokinetics, pharmacodynamics, with important differences among various progestogens. Generally, progestins are classified according to their parent molecule, of which often they keep some features. Derivatives of 19-nor-progesterone are characterized by high selectivity of action on progestin receptor. In particular, nomegestrol acetate (NomAc) shows an important progestational potency, neutral gluco-lipid profile, and antigonadotropic activity. It is used for treating menstrual cycle disorders and for hormone replacement therapy in menopause in association with an estrogen. In future, thanks to its antigonadotropic activity, NomAc will be used in estroprogestin combinations in fertile women, thus taking advantage of its tolerability profile and obtaining numerous non-contraceptive benefits as well. PMID:19749678

  17. The effect of oral sodium acetate administration on plasma acetate concentration and acid-base state in horses

    PubMed Central

    Waller, Amanda; Lindinger, Michael I

    2007-01-01

    Aim Sodium acetate (NaAcetate) has received some attention as an alkalinizing agent and possible alternative energy source for the horse, however the effects of oral administration remain largely unknown. The present study used the physicochemical approach to characterize the changes in acid-base status occurring after oral NaAcetate/acetic acid (NAA) administration in horses. Methods Jugular venous blood was sampled from 9 exercise-conditioned horses on 2 separate occasions, at rest and for 24 h following a competition exercise test (CET) designed to simulate the speed and endurance test of 3-day event. Immediately after the CETs horses were allowed water ad libitum and either: 1) 8 L of a hypertonic NaAcetate/acetic acid solution via nasogastric tube followed by a typical hay/grain meal (NAA trial); or 2) a hay/grain meal alone (Control trial). Results Oral NAA resulted in a profound plasma alkalosis marked by decreased plasma [H+] and increased plasma [TCO2] and [HCO3-] compared to Control. The primary contributor to the plasma alkalosis was an increased [SID], as a result of increased plasma [Na+] and decreased plasma [Cl-]. An increased [Atot], due to increased [PP] and a sustained increase in plasma [acetate], contributed a minor acidifying effect. Conclusion It is concluded that oral NaAcetate could be used as both an alkalinizing agent and an alternative energy source in the horse. PMID:18096070

  18. Current trends in salivary gland tight junctions.

    PubMed

    Baker, Olga J

    2016-01-01

    Tight junctions form a continuous intercellular barrier between epithelial cells that is required to separate tissue spaces and regulate selective movement of solutes across the epithelium. They are composed of strands containing integral membrane proteins (e.g., claudins, occludin and tricellulin, junctional adhesion molecules and the coxsackie adenovirus receptor). These proteins are anchored to the cytoskeleton via scaffolding proteins such as ZO-1 and ZO-2. In salivary glands, tight junctions are involved in polarized saliva secretion and barrier maintenance between the extracellular environment and the glandular lumen. This review seeks to provide an overview of what is currently known, as well as the major questions and future research directions, regarding tight junction expression, organization and function within salivary glands. PMID:27583188

  19. Existing approaches to tight rock laboratory petrophysics: a critical review

    NASA Astrophysics Data System (ADS)

    Konoshonkin, D. V.; Parnachev, S. V.

    2015-02-01

    A review of the existing methods for tight rock porosity, saturation, and permeability determination was performed taking into account that these methods should be applicable for Bazhenov formation evaluation. The following methods were considered: Archimedes mercury immersion; mercury displacement; caliper; helium pycnometry on crushed samples; nuclear magnetic resonance; modified retort method; modified Dean-Stark extraction; pulse decay method; and pressure decay test on crushed samples. The applicability of the pressure decay test on a crushed sample for Bazhenov formation evaluation is checked experimentally with the SMP-200 commercial permeameter. All the above listed methods were combined into five protocols for tight rock petrophysical evaluation. These protocols were analyzed and compared according to the following criteria: accuracy of the results; usage experience; time of measurements; easiness of interpretation; reliability and safety; price. The obtained results revealed that the most effective protocol is the one that includes pressure pulse on a core plug for permeability determination, He pycnometry and modified retort analysis on crushed samples for porosity and saturation determination. As there were cases when the proposed protocol was less effective vs. other protocols, a special scheme was suggested in order to choose the most effective protocol for tight rock petrophysical properties evaluation in definite conditions.

  20. Effect of a tight necktie on intraocular pressure

    PubMed Central

    Teng, C; Gurses-Ozden, R; Liebmann, J M; Tello, C; Ritch, R

    2003-01-01

    Aim: To evaluate the effect of a tight necktie on intraocular pressure (IOP) measurement using Goldmann applanation tonometry. Methods: 40 eyes of 20 normal subjects and 20 open angle glaucoma patients (all male) were enrolled. IOP was measured with an open shirt collar, 3 minutes after placing a tight necktie, and 3 minutes after loosening it. All measurements were made by the same examiner. Results: Mean IOP in normal subjects increased by 2.6 (SD 3.9) mm Hg (p=0.008, paired t test; range −3 to +14 mm Hg) and in glaucoma patients by 1.0 (1.8) mm Hg (p=0.02, paired t test; range −2 to +4.5 mm Hg). In normal subjects, IOP in 12 eyes was increased by ⩾2 mm Hg and in seven eyes by ⩾4 mm Hg. In glaucoma patients, IOP in six eyes was increased by ⩾2 mm Hg and in two eyes by ⩾4 mm Hg. Conclusion: A tight necktie increases IOP in both normal subjects and glaucoma patients and could affect the diagnosis and management of glaucoma. PMID:12881330

  1. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be produced by the calcium hydroxide neutralization of acetic acid. (b) The ingredient meets...

  2. The tight junction: a multifunctional complex.

    PubMed

    Schneeberger, Eveline E; Lynch, Robert D

    2004-06-01

    Multicellular organisms are separated from the external environment by a layer of epithelial cells whose integrity is maintained by intercellular junctional complexes composed of tight junctions, adherens junctions, and desmosomes, whereas gap junctions provide for intercellular communication. The aim of this review is to present an updated overview of recent developments in the area of tight junction biology. In a relatively short time, our knowledge of the tight junction has evolved from a relatively simple view of it being a permeability barrier in the paracellular space and a fence in the plane of the plasma membrane to one of it acting as a multicomponent, multifunctional complex that is involved in regulating numerous and diverse cell functions. A group of integral membrane proteins-occludin, claudins, and junction adhesion molecules-interact with an increasingly complex array of tight junction plaque proteins not only to regulate paracellular solute and water flux but also to integrate such diverse processes as gene transcription, tumor suppression, cell proliferation, and cell polarity. PMID:15151915

  3. Tight junction, selective permeability, and related diseases.

    PubMed

    Krug, Susanne M; Schulzke, Jörg D; Fromm, Michael

    2014-12-01

    The tight junction forms a barrier against unlimited paracellular passage but some of the tight junction proteins just do the opposite, they form extracellular channels zigzagging between lateral membranes of neighboring cells. All of these channel-forming proteins and even some of the barrier formers exhibit selectivity, which means that they prefer certain substances over others. All channel formers exhibit at least one of the three types of selectivity: for cations (claudin-2, -10b, -15), for anions (claudin-10a, -17) or for water (claudin-2). Also some, but not all, barrier-forming claudins are charge-selective (claudin-4, -8, -14). Moreover, occludin and tricellulin turned out to be relevant for barrier formation against macromolecule passage. Tight junction proteins are dysregulated or can be genetically defective in numerous diseases, which may lead to three effects: (i) impaired paracellular transport e.g. causing magnesium loss in the kidney, (ii) increased paracellular transport of solutes and water e.g. causing leak-flux diarrhea in the intestine, and (iii) increased permeability to large molecules e.g. unwanted intestinal pathogen uptake fueling inflammatory processes. This review gives an overview on the properties of tight junction proteins featuring selective permeability, and in this context explains how these proteins induce or aggravate diseases. PMID:25220018

  4. Hormonal regulation of hepatocyte tight junctional permeability

    SciTech Connect

    Lowe, P.J.; Miyai, K.; Steinbach, J.H.; Hardison, W.G.M. Univ. of California, San Diego )

    1988-10-01

    The authors have investigated the effects of hormones on the permeability of the hepatocyte tight junction to two probes, ({sup 14}C)sucrose and horseradish peroxidase, using one-pass perfused rat livers. Using a single injection of horseradish peroxidase the authors have demonstrated that this probe can enter bile by two pathways that are kinetically distinct, a fast pathway, which corresponds to the passage of the probe through the hepatocyte tight junctions, and a slow pathway, which corresponds to the transcytotic entry into bile. The passage of horseradish peroxidase through the hepatocyte tight junctions was confirmed by electron microscopic histochemistry. Vasopressin, epinephrine, and angiotensin II, hormones that act in the hepatocyte through the intracellular mediators calcium, the inositol polyphosphates, and diacylglycerol, increased the bile-to-perfusion fluid ratio of ({sup 14}C)sucrose and the rapid entry of horseradish peroxidase into bile, indicating that the permeability of the tight junctions to these probes was increased. The effect of these hormones was dose dependent and in the cases of angiotensin II and epinephrine was inhibited by the specific inhibitors (Sar{sup 1},Thr{sup 8})angiotensin II and prazosin, respectively. Dibutyryl adenosine 3{prime},5{prime}-cyclic monophosphate did not affect the ({sup 14}C)sucrose bile-to-perfusion fluid ratio or the fast entry of horseradish peroxidase into bile. These results suggest that the hepatocyte tight junction can no longer be considered a static system of pores separating blood from bile. It is rather a dynamic barrier potentially capable of influencing the composition of the bile.

  5. Tight junction modulation by chitosan nanoparticles: comparison with chitosan solution.

    PubMed

    Vllasaliu, Driton; Exposito-Harris, Ruth; Heras, Angeles; Casettari, Luca; Garnett, Martin; Illum, Lisbeth; Stolnik, Snow

    2010-11-15

    Present work investigates the potential of chitosan nanoparticles, formulated by the ionic gelation with tripolyphosphate (TPP), to open the cellular tight junctions and in doing so, improve the permeability of model macromolecules. A comparison is made with chitosan solution at equivalent concentrations. Initial work assessed cytotoxicity (through MTS and LDH assays) of chitosan nanoparticles and solutions on Calu-3 cells. Subsequently, a concentration of chitosan nanoparticles and solution exhibiting minimal toxicity was used to investigate the effect on TEER and macromolecular permeability across filter-cultured Calu-3 monolayer. Chitosan nanoparticles and solution were also tested for their effect on the distribution of the tight junction protein, zonnula occludens-1 (ZO-1). Chitosan nanoparticles produced a sharp and reversible decrease in TEER and increased the permeability of two FITC-dextrans (FDs), FD4 (MW 4 kDa) and FD10 (MW 10 kDa), with effects of a similar magnitude to chitosan solution. Chitosan nanoparticles produced changes in ZO-1 distribution similar to chitosan solution, indicating a tight junction effect. While there was no improvement in permeability with chitosan nanoparticles compared to solution, nanoparticles provide the potential for drug incorporation, and hence the possibility for providing controlled drug release and protection from enzymatic degradation. PMID:20727955

  6. Acetoxychavicol Acetate, an Antifungal Component of Alpinia galanga1.

    PubMed

    Janssen, A M; Scheffer, J J

    1985-12-01

    The essential oils from fresh and dried rhizomes of ALPINIA GALANGA showed an antimicrobial activity against gram-positive bacteria, a yeast and some dermatophytes, using the agar overlay technique. The main components of the oils were also tested and terpinen-4-ol was found most active. An N-pentane/diethyl ether extract of dried rhizomes was active against TRICHOPHYTON MENTAGROPHYTES. 1'-Acetoxychavicol acetate, 1'-acetoxyeugenol acetate and 1'-hydroxychavicol acetate identified by MS and NMR were found in the antifungally active fractions obtained by LSC. Acetoxychavicol acetate was active against the seven fungi tested and its MIC value for dermatophytes ranged from 50 to 250 microg/ml. Dried sliced rhizomes contained 1.5% of this compound. The compound was not found in rhizomes of ALPINIA OFFICINARUM, ZINGIBER OFFICINALE and KAEMPFERIA GALANGA. PMID:17345272

  7. SAGA Complex Components and Acetate Repression in Aspergillus nidulans

    PubMed Central

    Georgakopoulos, Paraskevi; Lockington, Robin A.; Kelly, Joan M.

    2012-01-01

    Alongside the well-established carbon catabolite repression by glucose and other sugars, acetate causes repression in Aspergillus nidulans. Mutations in creA, encoding the transcriptional repressor involved in glucose repression, also affect acetate repression, but mutations in creB or creC, encoding components of a deubiquitination system, do not. To understand the effects of acetate, we used a mutational screen that was similar to screens that uncovered mutations in creA, creB, and creC, except that glucose was replaced by acetate to identify mutations that were affected for repression by acetate but not by glucose. We uncovered mutations in acdX, homologous to the yeast SAGA component gene SPT8, which in growth tests showed derepression for acetate repression but not for glucose repression. We also made mutations in sptC, homologous to the yeast SAGA component gene SPT3, which showed a similar phenotype. We found that acetate repression is complex, and analysis of facA mutations (lacking acetyl CoA synthetase) indicates that acetate metabolism is required for repression of some systems (proline metabolism) but not for others (acetamide metabolism). Although plate tests indicated that acdX- and sptC-null mutations led to derepressed alcohol dehydrogenase activity, reverse-transcription quantitative real-time polymerase chain reaction showed no derepression of alcA or aldA but rather elevated induced levels. Our results indicate that acetate repression is due to repression via CreA together with metabolic changes rather than due to an independent regulatory control mechanism. PMID:23173087

  8. SAGA complex components and acetate repression in Aspergillus nidulans.

    PubMed

    Georgakopoulos, Paraskevi; Lockington, Robin A; Kelly, Joan M

    2012-11-01

    Alongside the well-established carbon catabolite repression by glucose and other sugars, acetate causes repression in Aspergillus nidulans. Mutations in creA, encoding the transcriptional repressor involved in glucose repression, also affect acetate repression, but mutations in creB or creC, encoding components of a deubiquitination system, do not. To understand the effects of acetate, we used a mutational screen that was similar to screens that uncovered mutations in creA, creB, and creC, except that glucose was replaced by acetate to identify mutations that were affected for repression by acetate but not by glucose. We uncovered mutations in acdX, homologous to the yeast SAGA component gene SPT8, which in growth tests showed derepression for acetate repression but not for glucose repression. We also made mutations in sptC, homologous to the yeast SAGA component gene SPT3, which showed a similar phenotype. We found that acetate repression is complex, and analysis of facA mutations (lacking acetyl CoA synthetase) indicates that acetate metabolism is required for repression of some systems (proline metabolism) but not for others (acetamide metabolism). Although plate tests indicated that acdX- and sptC-null mutations led to derepressed alcohol dehydrogenase activity, reverse-transcription quantitative real-time polymerase chain reaction showed no derepression of alcA or aldA but rather elevated induced levels. Our results indicate that acetate repression is due to repression via CreA together with metabolic changes rather than due to an independent regulatory control mechanism. PMID:23173087

  9. Comparison of growth, acetate production, and acetate inhibition of Escherichia coli strains in batch and fed-batch fermentations.

    PubMed

    Luli, G W; Strohl, W R

    1990-04-01

    The growth characteristics and acetate production of several Escherichia coli strains were compared by using shake flasks, batch fermentations, and glucose-feedback-controlled fed-batch fermentations to assess the potential of each strain to grow at high cell densities. Of the E. coli strains tested, including JM105, B, W3110, W3100, HB101, DH1, CSH50, MC1060, JRG1046, and JRG1061, strains JM105 and B were found to have the greatest relative biomass accumulation, strain MC1060 accumulated the highest concentrations of acetic acid, and strain B had the highest growth rates under the conditions tested. In glucose-feedback-controlled fed-batch fermentations, strains B and JM105 produced only 2 g of acetate.liter-1 while accumulating up to 30 g of biomass.liter-1. Under identical conditions, strains HB101 and MC1060 accumulated less than 10 g of biomass.liter-1 and strain MC1060 produced 8 g of acetate.liter-1. The addition of various concentrations of sodium acetate to the growth medium resulted in a logarithmic decrease, with respect to acetate concentration, in the growth rates of E. coli JM105, JM105(pOS4201), and JRG1061. These data indicated that the growth of the E. coli strains was likely to be inhibited by the acetate they produced when grown on media containing glucose. A model for the inhibition of growth of E. coli by acetate was derived from these experiments to explain the inhibition of acetate on E. coli strains at neutral pH. PMID:2187400

  10. Comparison of growth, acetate production, and acetate inhibition of Escherichia coli strains in batch and fed-batch fermentations.

    PubMed Central

    Luli, G W; Strohl, W R

    1990-01-01

    The growth characteristics and acetate production of several Escherichia coli strains were compared by using shake flasks, batch fermentations, and glucose-feedback-controlled fed-batch fermentations to assess the potential of each strain to grow at high cell densities. Of the E. coli strains tested, including JM105, B, W3110, W3100, HB101, DH1, CSH50, MC1060, JRG1046, and JRG1061, strains JM105 and B were found to have the greatest relative biomass accumulation, strain MC1060 accumulated the highest concentrations of acetic acid, and strain B had the highest growth rates under the conditions tested. In glucose-feedback-controlled fed-batch fermentations, strains B and JM105 produced only 2 g of acetate.liter-1 while accumulating up to 30 g of biomass.liter-1. Under identical conditions, strains HB101 and MC1060 accumulated less than 10 g of biomass.liter-1 and strain MC1060 produced 8 g of acetate.liter-1. The addition of various concentrations of sodium acetate to the growth medium resulted in a logarithmic decrease, with respect to acetate concentration, in the growth rates of E. coli JM105, JM105(pOS4201), and JRG1061. These data indicated that the growth of the E. coli strains was likely to be inhibited by the acetate they produced when grown on media containing glucose. A model for the inhibition of growth of E. coli by acetate was derived from these experiments to explain the inhibition of acetate on E. coli strains at neutral pH. PMID:2187400

  11. Petrophysical approach of tight gas reservoir including shaly sand

    NASA Astrophysics Data System (ADS)

    Kim, Taeyoun; Hwang, Seho; Jang, Seonghyung

    2016-04-01

    Since porosity of tight gas reservoir is very small, it is very important to estimate porosity from well logs precisely. If well logging porosity is not appropriate or does not match with core-tested porosity, other rock properties related to porosity cannot be estimated correctly. In case of shaly sand, we have to consider clay volume for estimating water saturation and effective porosity. The purpose of this study is to address a process issue for estimating total porosity, water saturation of tight gas reservoir including shaly sand from well logs. The methods for estimating total porosity with difference well logging responses include neutron-density method, neutron-sonic method, density method, sonic method and compared with core-tested porosity. After calculating correlation coefficient between well logging total porosity and core-tested porosity, we select a best matched result. Using this result, we try to estimate water saturation from well logs. Normally, Archie's method is very famous for calculating water saturation. Since it assumes clean sand condition, we tried to apply other methods considering clay volume. In this study, we applied Archie's method, dual water method, and Indonesian method for estimating water saturation from well logs and compared with core-tested water saturation.

  12. Molecular organization of tricellular tight junctions.

    PubMed

    Furuse, Mikio; Izumi, Yasushi; Oda, Yukako; Higashi, Tomohito; Iwamoto, Noriko

    2014-01-01

    When the apicolateral border of epithelial cells is compared with a polygon, its sides correspond to the apical junctional complex, where cell adhesion molecules assemble from the plasma membranes of two adjacent cells. On the other hand, its vertices correspond to tricellular contacts, where the corners of three cells meet. Vertebrate tricellular contacts have specialized structures of tight junctions, termed tricellular tight junctions (tTJs). tTJs were identified by electron microscopic observations more than 40 years ago, but have been largely forgotten in epithelial cell biology since then. The identification of tricellulin and angulin family proteins as tTJ-associated membrane proteins has enabled us to study tTJs in terms of not only the paracellular barrier function but also unknown characteristics of epithelial cell corners via molecular biological approaches. PMID:25097825

  13. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    1998-09-30

    During this quarter, work began on the regional structural and geologic analysis of the greater Green River basin (GGRB) in southwestern Wyoming, northwestern Colorado and northeastern Utah. The ultimate objective of the regional analysis is to apply the techniques developed and demonstrated during earlier phases of the project to sweet-spot delineation in a relatively new and underexplored play: tight gas from continuous-type Upper Cretaceous reservoirs of the GGRB. The primary goal of this work is to partition and high-grade the greater Green River basin for exploration efforts in the Cretaceous tight gas play. The work plan for the quarter of January 1, 1998--March 31, 1998 consisted of three tasks: (1) Acquire necessary data and develop base map of study area; (2) Process data for analysis; and (3) Initiate structural study. The first task and second tasks were completed during this reporting period. The third task was initiated and work continues.

  14. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    1998-11-30

    The goal of the work this quarter has been to partition and high-grade the Greater Green River basin for exploration efforts in the Upper Cretaceous tight gas play and to initiate resource assessment of the basin. The work plan for the quarter of July 1-September 30, 1998 comprised three tasks: (1) Refining the exploration process for deep, naturally fractured gas reservoirs; (2) Partitioning of the basin based on structure and areas of overpressure; (3) Examination of the Kinney and Canyon Creek fields with respect to the Cretaceous tight gas play and initiation of the resource assessment of the Vermilion sub-basin partition (which contains these two fields); and (4) Initiation analysis of the Deep Green River Partition with respect to the Stratos well and assessment of the resource in the partition.

  15. On-line air-tightness and insertion loss simultaneous detection method of high air-tightness fiber optic penetration connector

    NASA Astrophysics Data System (ADS)

    Zhang, Jingchuan; Yang, Xiaoning; Wang, Jing; Jiang, Junfeng

    2015-08-01

    The high air-tightness multicore fiber optic penetration connector is a core component for the optical fiber sensing and communication technologies applied in the space environment simulator under the vacuum thermal environment. High air-tightness and insertion loss are the two key indexes of the fiber optic penetration connector. The air-tightness and insertion loss on-line synchronous detection method was proposed. First, established hardware-in-the-loop testing platform by using the vacuum pumping system, the vacuum vessel, the helium mass spectrometer leak detector and optical time-domain reflectmeter, then, described the air tightness and insertion loss on-line detection principle, finally, designed a detection test scheme and air-tightness and insertion loss were tested. Experimental results indicate that the leakage rate is lower than 1.0×10-7Pa•L/S, the minimum of which is1.0×10-10Pa•L/S and the insertion loss at wave length window 1550 nm is +/-0.07db, which is less than +/-0.1db. It can lay the data basis for the design of opto-mechanical combination and later period fine processing.

  16. Tight Binding Models in Cold Atoms Physics

    NASA Astrophysics Data System (ADS)

    Zakrzewski, J.

    2007-05-01

    Cold atomic gases placed in optical lattice potentials offer a unique tool to study simple tight binding models. Both the standard cases known from the condensed matter theory as well as novel situations may be addressed. Cold atoms setting allows for a precise control of parameters of the systems discussed, stimulating new questions and problems. The attempts to treat disorder in a controlled fashion are addressed in detail.

  17. Tight dual models of pore spaces

    NASA Astrophysics Data System (ADS)

    Glantz, Roland; Hilpert, Markus

    2008-05-01

    The pore throats in a porous medium control permeability, drainage, and straining through their pore scale geometry and through the way they are connected via pore bodies on the macroscale. Likewise, imbibition is controlled through the geometry of the pore bodies (pore scale) and through the way the pore bodies are connected via pore throats on the macroscale. In an effort to account for both scales at the same time we recently introduced an image-based model for pore spaces that consists of two parts related by duality: (1) a decomposition of a polyhedral pore space into polyhedral pore bodies separated by polygonal pore throats and (2) a polygonal pore network that is homotopy equivalent to the pore space. In this paper we stick to the dual concept while amending the definition of the pore throats and, as a consequence, the other elements of the dual model. Formerly, the pore throats consisted of single two-dimensional Delaunay cells, while they now usually consist of more than one two-dimensional Delaunay cell and extend all the way into the narrowing ends of the pore channel cross sections. This is the first reason for naming the amended dual model "tight". The second reason is that the formation of the pore throats is now guided by an objective function that always attains its global optimum (tight optimization). At the end of the paper we report on simulations of drainage performed on tight dual models derived from simulated sphere packings and 3D gray-level images. The C-code for the generation of the tight dual model and the simulation of drainage is publicly available at https://jshare.johnshopkins.edu/mhilper1/public_html/tdm.html.

  18. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    Decker, D.

    1995-05-01

    Exploration strategies are needed to identify subtle basement features critical to locating fractured regions in advance of drilling in tight gas reservoirs. The Piceance Basin served as a demonstration site for an analysis utilizing aeromagnetic surveys, remote sensing, Landsat Thematic Mapper, and Side Looking Airborne Radar imagery for the basin and surrounding areas. Spatially detailed aeromagnetic maps were used to to interpret zones of basement structure.

  19. Supplies tight for CFC-11 and -12

    SciTech Connect

    Rotman, D.; Kirschner, E.

    1992-09-30

    With US 1992 production of chlorofluorocarbon (CFC)-11 and -12 cut back to less than 50% of 1986 levels, supplies are tight and prices are rising. While CFC customers can find the product, the first half of the year was particularly bumpy, marked by shortages of key feedstock carbon tetrachloride. US carbon tet production dropped from 400 million lbs in 1991 to 250 million lbs because of a series of plant closings in 1991. The lack of carbon tet, says a spokesman for one CFC producer, was [open quotes]a real disruption.[close quotes] And, says Jerry Dziedzic, general manager, fluorochemicals at Elf Atochem (Philadelphia), in a such a tight market [open quotes]even a little hiccup can throw the system out of whack.[close quotes] Dow senior project manager Jeff Sullivan says CFC producers were expecting a drop in 1992 sales when the company's Sarnia, ON carbon tet plant closing was announced. By the time CFC producers recognized that demand would remain at 1991 levels, the shutdown was under way. [open quotes]We were caught short because they were caught short.[close quotes] While the carbon tet shortage has lessened recently, supplies of CFC-11 and 12 are expected to remain tight through the rest of the year. But that could ease toward year-end as hydrofluorocarbon-141b increasingly replaces CFC-11.

  20. Geologic characterization of tight gas reservoirs

    SciTech Connect

    Law, B.E.

    1990-12-01

    The objectives of US Geological Survey (USGS) work during FY 89 were to conduct geologic research characterizing tight gas-bearing sandstone reservoirs and their resources in the western United States. Our research has been regional in scope but, in some basins, our investigations have focused on single wells or small areas containing several wells where a large amount of data is available. The investigations, include structure, stratigraphy, petrography, x-ray mineralogy, source-rock evaluation, formation pressure and temperature, borehole geophysics, thermal maturity mapping, fission-track age dating, fluid-inclusion thermometry, and isotopic geochemistry. The objectives of these investigations are to provide geologic models that can be compared and utilized in tight gas-bearing sequences elsewhere. Nearly all of our work during FY 89 was devoted to developing a computer-based system for the Uinta basin and collecting, analyzing, and storage of data. The data base, when completed will contain various types of stratigraphic, organic chemistry, petrographic, production, engineering, and other information that relate to the petroleum geology of the Uinta basin, and in particular, to the tight gas-bearing strata. 16 refs., 3 figs.

  1. Field Validation of ICF Residential Building Air-Tightness

    SciTech Connect

    Sacs, I.; Ternes, M.P.

    2001-01-01

    Recent advances in home construction methods have made considerable progress in addressing energy savings issues. Certain methods are potentially capable of tightening the building envelope, consequently reducing air leakage and minimizing heating and air conditioning related energy losses. Insulated concrete form (ICF) is an economically viable alternative to traditional woodframe construction. Two homes, one of wood-frame, the other of ICF construction, were studied. Standard air leakage testing procedures were used to compare air tightness characteristics achieved by the two construction types. The ICF home showed consistently lower values for air leakage in these tests. The buildings otherwise provided similar data during testing, suggesting that the difference in values is due to greater airtight integrity of the ICF construction method. Testing on more homes is necessary to be conclusive. However, ICF construction shows promise as a tighter building envelope construction method.

  2. Multiple-anion nonvolatile acetal (MANA) resists

    NASA Astrophysics Data System (ADS)

    Guevremont, Jeffrey M.; Brainard, Robert L.; Reeves, Scott D.; Zhou, Xin; Nguyen, Thinh B.; Mackevich, Joseph F.; Anderson, Erik H.; Taylor, Gary N.

    2001-08-01

    New acetal or ketal blocking reagents were investigated for use in e-beam lithography and compared with the performance of ethyl vinyl either (EVE). Three blocking groups, (alpha) -Angelicalactone (AL), 6-methylene-5,6-benzo-1,4- dioxane (MBD), and MANA50 (an undisclosed blocking group used to show the potential of this chemistry) were reacted with poly(p-hydroxystyrene) (PHS) under acid catalyzed conditions to form AL-PHS, MBD-PHS, MANA50-PHS. The performance objectives pursued in the design of these new materials was to use acetal (ketal) chemistry to deliver wide process latitudes (e.g. good PED performance and minimal PEB sensitivity), use high molecular weight blocking groups to eliminate outgassing, and use the novel concept of multiple anions to deliver lithographic performance. These new materials are called Multiple Anion Nonvolatile Acetal (MANA) resists. Resists films were exposed with 50kV electrons, post exposure baked (PEB), and developed with 0.26 N TMAH. Resists prepared with the third blocking group, MANA50, gave contrast and imaging performance independent of PEB humidity and were relatively insensitive to PEB temperature and post exposure delay (PED). These resists gave the best resolution (90 nm) and profiles of all the materials tested, as well as showing no outgassing (as measured by film thickness loss).

  3. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium acetate. 184.1185 Section 184.1185 Food and... Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may...

  4. Bioavailability of acetate from two vinegar supplements: capsule and drink.

    PubMed

    Sugiyama, Shino; Fushimi, Takashi; Kishi, Mikiya; Irie, Shin; Tsuji, Shigeki; Hosokawa, Natsuko; Kaga, Takayuki

    2010-01-01

    The bioavailability of acetate in various vinegar supplements, e.g. as capsules and drinks, remains unclear. Thus, we conducted a cross-over clinical study in 30 healthy subjects. After an overnight fast, subjects received each test sample in a randomised sequence: 9 vinegar capsules (containing 750 mg acetic acid in total) with 150 mL of water, 100 mL of vinegar drink (containing 750 mg acetic acid), and 150 mL of water as reference. Blood samples were collected before (defined as 0 min), at 15, 30, 45, 60, 90, 120 and 180 min after each test sample intake. In the vinegar drink group, serum acetate concentration increased immediately after intake, peaked at 15 min and returned to baseline at 90 min. That in the vinegar capsule group rose slowly, peaked at 30 min and returned to baseline at 120 min. The peak values in both groups exceeded 200 µmol/L, the physiologically active concentration confirmed by in vitro experiment. In the reference group, levels remained constant throughout the 180-min period. The amount of absorbed acetate from the vinegar capsule group and the drink group was evaluated by the difference value of the area under the serum acetate concentration-time curve (AUC) between in each vinegar group and in the reference group (expressed as AUC(capsule-ref) and AUC(drink-ref ), respectively). AUC(capsule-ref) was about 80% of AUC(drink-ref ), but there was no significant difference between them. PMID:20924150

  5. Epithelial tight junctions in intestinal inflammation.

    PubMed

    Schulzke, Joerg D; Ploeger, Svenja; Amasheh, Maren; Fromm, Anja; Zeissig, Sebastian; Troeger, Hanno; Richter, Jan; Bojarski, Christian; Schumann, Michael; Fromm, Michael

    2009-05-01

    The epithelium in inflamed intestinal segments of patients with Crohn's disease is characterized by a reduction of tight junction strands, strand breaks, and alterations of tight junction protein content and composition. In ulcerative colitis, epithelial leaks appear early due to micro-erosions resulting from upregulated epithelial apoptosis and in addition to a prominent increase of claudin-2. Th1-cytokine effects by interferon-gamma in combination with TNFalpha are important for epithelial damage in Crohn's disease, while interleukin-13 (IL-13) is the key effector cytokine in ulcerative colitis stimulating apoptosis and upregulation of claudin-2 expression. Focal lesions caused by apoptotic epithelial cells contribute to barrier disturbance in IBD by their own conductivity and by confluence toward apoptotic foci or erosions. Another type of intestinal barrier defect can arise from alpha-hemolysin harboring E. coli strains among the physiological flora, which can gain pathologic relevance in combination with proinflammatory cytokines under inflammatory conditions. On the other hand, intestinal barrier impairment can also result from transcellular antigen translocation via an initial endocytotic uptake into early endosomes, and this is intensified by proinflammatory cytokines as interferon-gamma and may thus play a relevant role in the onset of IBD. Taken together, barrier defects contribute to diarrhea by a leak flux mechanism (e.g., in IBD) and can cause mucosal inflammation by luminal antigen uptake. Immune regulation of epithelial functions by cytokines may cause barrier dysfunction not only by tight junction impairments but also by apoptotic leaks, transcytotic mechanisms, and mucosal gross lesions. PMID:19538319

  6. Coughing Wheezing Shortness of Breath Tightness in Chest

    MedlinePlus

    ... Issues Coughing Wheezing Shortness of Breath Tightness in Chest Past Issues / Fall 2006 Table of Contents For ... short of breath or feel tightness in your chest, you might have asthma. If you do, you ...

  7. Coughing Wheezing Shortness of Breath Tightness in Chest

    MedlinePlus

    ... Current Issue Past Issues Coughing Wheezing Shortness of Breath Tightness in Chest Past Issues / Fall 2006 Table ... you cough a lot, wheeze, are short of breath or feel tightness in your chest, you might ...

  8. Inward leakage in tight-fitting PAPRs.

    PubMed

    Koh, Frank C; Johnson, Arthur T; Rehak, Timothy E

    2011-01-01

    A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves. In both cases, the leakage was not enough for fog to appear at the mouth of the head form. PMID:21647352

  9. Inward Leakage in Tight-Fitting PAPRs

    PubMed Central

    Koh, Frank C.; Johnson, Arthur T.; Rehak, Timothy E.

    2011-01-01

    A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves. In both cases, the leakage was not enough for fog to appear at the mouth of the head form. PMID:21647352

  10. Terrestrial tight oil reservoir characteristics and Graded Resource Assessment in China

    NASA Astrophysics Data System (ADS)

    Wang, Shejiao; Wu, Xiaozhi; Guo, Giulin

    2016-04-01

    China. The porosity is 2-14%(average 5-10%)and the permeability is less than 1mD. The laboratory test and exploration practice confirmed that the oil content was positively related to physical property. The higher the porosity, the better the oil content will have. (3) Source rock and reservoir are superimposed. From the contact relationship of source rock and reservoir, the reservoir developed in the source rock has the advantage of capturing oil and gas, so the oil saturation can be as high as 70-80%. (4) The increased pressure caused by hydrocarbon generation and the connected fracture are the key factors for tight oil accumulation. The Fuyu tight oil formed underling source rock in Songliao Basin is a good example. The fracture system is the key factor for tight oil accumulation. Considering the strong heterogeneity of terrestrial tight oil reservoir in china, we create hierarchical resource abundance analogy, EUR analogy, cell element volumetric methods to evaluate tight oil resource potential. In order to find exploration "sweet spots", establishing tight oil resource classification evaluation standards are key steps to objectively evaluate tight oil resource distribution. The resource classification evaluation standards are established by the relationship analysis between reservoir properties and oil properties, and the correlation analysis between production, resource abundance, and reservoir thickness. The first-grade tight oil resource, which is recently available and can easily be developed, has following main parameters: the porosity is greater than 8%, thickness is over 10m, resource abundance is above 150,000 tons / km2, and pressure coefficient is greater than 1.3; The second-grade tight oil resource is currently unavailable, but with advanced technology can expected to be developed. The main parameters are as following: the porosity is 5% -8%, thickness is less than 5-10m, resource abundance is 50000-150000 tons / km2, the pressure coefficient is 1.0 to

  11. Tight Fits for Americas Next Moon Rocket, Ares V

    NASA Technical Reports Server (NTRS)

    Jaap, John; Fisher, Wyatt; Richardson, Lea

    2010-01-01

    America has begun the development of a new heavy lift rocket which will enable humans to return to the moon and reach even farther destinations. Five decades ago, the National Aeronautics and Space Administration designed a system (called Saturn/Apollo) to carry men to the moon and back; the rocket which boosted them to the moon was the Saturn V. Saturn V was huge relative to contemporary rockets and is still the largest rocket ever launched. The new moon rocket is called Ares V. It will insert 40% more payload into low earth orbit than Saturn V; and after docking with the crew spacecraft, it will insert 50% more payload onto the translunar trajectory than Saturn V. The current design of Ares V calls for two liquid-fueled stages and 2 "strap-on" solid rockets. The solid rockets are extended-length versions of the solid rockets used on the Shuttle. The diameter of the liquid stages is at least as large as the first stage of the Saturn V; the height of the lower liquid stage (called the core stage) is longer than the external tank of the Shuttle. Huge rockets require huge infrastructure and, during the Saturn/Apollo era, America invested significantly in manufacturing, assembly and launch facilities which are still in use today. Since the Saturn/Apollo era, America has invested in additional infrastructure for the Shuttle program. Ares V must utilize this existing infrastructure, with reasonable modifications. Building a rocket with 50% more capability in the same buildings, testing it in the same test stands, shipping on the same canals under the same bridges, assembling it in the same building, rolling it to the pad on the same crawler, and launching it from the same launch pad is an engineering and logistics challenge which goes hand-in-hand with designing the structure, tanks, turbines, engines, software, etc. necessary to carry such a large payload to earth orbit and to the moon. This paper quantitatively discusses the significant "tight fits" that are

  12. Desmopressin Acetate in Intracranial Haemorrhage

    PubMed Central

    Kapapa, Thomas; Röhrer, Stefan; Struve, Sabine; Petscher, Matthias; König, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter

    2014-01-01

    Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ≤ 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients. PMID:25610644

  13. 18 CFR 270.304 - Tight formation gas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Tight formation gas... Requirements for Filings With Jurisdictional Agencies § 270.304 Tight formation gas. A person seeking a determination that natural gas is tight formation gas must file with the jurisdictional agency an...

  14. Leak-tight vertical membrane microvalves.

    PubMed

    Hansson, Jonas; Hillmering, Mikael; Haraldsson, Tommy; van der Wijngaart, Wouter

    2016-04-12

    Pneumatic microvalves are fundamental control components in a large range of microfluidic applications. Their key performance parameters are small size, i.e. occupying a minimum of microfluidic real estate, low flow resistance in the open state, and leak-tight closing at limited control pressures. In this work we present the successful design, realization and evaluation of the first leak-tight, vertical membrane, pneumatic microvalves. The realization of the vertical membrane microvalves is enabled by a novel dual-sided molding method for microstructuring monolithic 3D microfluidic networks in PDMS in a single step, eliminating the need for layer-to-layer alignment during bonding. We demonstrate minimum lateral device features down to 20-30 μm in size, and vertical via density of ∼30 000 per cm(2), which provides significant gains in chip real estate compared to previously reported PDMS manufacturing methods. In contrast to horizontal membrane microvalves, there are no manufacturing restrictions on the cross-sectional geometry of the flow channel of the vertical membrane microvalves. This allows tuning the design towards lower closing pressure or lower open state flow resistance compared to those of horizontal membrane microvalves. PMID:26983557

  15. Tight gas reservoirs: A visual depiction

    SciTech Connect

    Not Available

    1993-12-01

    Future gas supplies in the US will depend on an increasing contribution from unconventional sources such as overpressured and tight gas reservoirs. Exploitation of these resources and their conversion to economically producible gas reserves represents a major challenge. Meeting this challenge will require not only the continuing development and application of new technologies, but also a detailed understanding of the complex nature of the reservoirs themselves. This report seeks to promote understanding of these reservoirs by providing examples. Examples of gas productive overpressured tight reservoirs in the Greater Green River Basin, Wyoming are presented. These examples show log data (raw and interpreted), well completion and stimulation information, and production decline curves. A sampling of wells from the Lewis and Mesaverde formations are included. Both poor and good wells have been chosen to illustrate the range of productivity that is observed. The second section of this document displays decline curves and completion details for 30 of the best wells in the Greater Green River Basin. These are included to illustrate the potential that is present when wells are fortuitously located with respect to local stratigraphy and natural fracturing, and are successfully hydraulically fractured.

  16. Tricellular Tight Junctions in the Inner Ear

    PubMed Central

    2016-01-01

    Tight junctions (TJs) are structures that seal the space between the epithelial cell sheets. In the inner ear, the barrier function of TJs is indispensable for the separation of the endolymphatic and perilymphatic spaces, which is essential for the generation and maintenance of the endocochlear potential (EP). TJs are formed by the intercellular binding of membrane proteins, known as claudins, and mutations in these proteins cause deafness in humans and mice. Within the epithelial cell sheet, however, a bound structure is present at the site where the corners of three cells meet (tricellular tight junctions (tTJs)), and the maintenance of the barrier function at this location cannot be explained by the claudins alone. Tricellulin and the angulin family of proteins (angulin-1/LSR, angulin-2/ILDR1, and angulin-3/ILDR2) have been identified as tTJ-associated proteins. Tricellulin and ILDR1 are localized at the tTJ and alterations in these proteins have been reported to be involved in deafness. In this review, we will present the current state of knowledge for tTJs. PMID:27195292

  17. Tricellular Tight Junctions in the Inner Ear.

    PubMed

    Kitajiri, Shin-Ichiro; Katsuno, Tatsuya

    2016-01-01

    Tight junctions (TJs) are structures that seal the space between the epithelial cell sheets. In the inner ear, the barrier function of TJs is indispensable for the separation of the endolymphatic and perilymphatic spaces, which is essential for the generation and maintenance of the endocochlear potential (EP). TJs are formed by the intercellular binding of membrane proteins, known as claudins, and mutations in these proteins cause deafness in humans and mice. Within the epithelial cell sheet, however, a bound structure is present at the site where the corners of three cells meet (tricellular tight junctions (tTJs)), and the maintenance of the barrier function at this location cannot be explained by the claudins alone. Tricellulin and the angulin family of proteins (angulin-1/LSR, angulin-2/ILDR1, and angulin-3/ILDR2) have been identified as tTJ-associated proteins. Tricellulin and ILDR1 are localized at the tTJ and alterations in these proteins have been reported to be involved in deafness. In this review, we will present the current state of knowledge for tTJs. PMID:27195292

  18. Reductive opening of carbohydrate phenylsulfonylethylidene (PSE) acetals.

    PubMed

    Chéry, Florence; Cabianca, Elena; Tatibouët, Arnaud; De Lucchi, Ottorino; Lindhorst, Thisbe K; Rollin, Patrick

    2015-11-19

    The phenylsulfonylethylidene (PSE) acetal is a relatively new protecting group in carbohydrate chemistry. However, carbohydrate-derived phenylsulfonylethylidene (PSE) acetals show a different behavior in reductive desulfonylation than simple symmetrical acetals. Here we have investigated various SET-type reaction conditions in order to open PSE acetals regioselectively and to produce chiral ω-hydroxyethenyl ethers. Whereas sodium amalgam leads to a mixture of regioisomeric vinyl ethers besides the ethylidene acetal, samarium iodide is suited for regioselective ring opening. This is shown with seven different carbohydrate PSE acetals, both of the 1,3-dioxane and the 1,3-dioxolane type. PMID:26469209

  19. S0 Tight Loop Studies on ICHIRO 9-Cell Cavities

    SciTech Connect

    Furuta, Fumio; Konomi, T.; Saito, Kenji; Bice, Damon; Crawford, Anthony C.; Geng, Rongli

    2009-11-01

    We have continued high gradient R&D of ICHIRO 9-cell cavities at KEK. ICHIRO 9-cell cavity #5 (I9#5) that has no end groups on beam tube to focus on high gradient sent to Jlab as S0 tight loop study. Surface treatments and vertical test were repeated 3 times at Jlab, and then I9#5 sent back to KEK. We also repeated surface treatments and test at KEK. Maximum gradients were 36.5MV/m at Jlab, and 33.7MV/m at KEK so far. Now we are struggling with the puzzle why the results of singles do not work well on 9-cell cavities.

  20. Naturally fractured tight gas reservoir detection optimization. Quarterly technical progress report, April 1995--June 1995

    SciTech Connect

    1995-08-01

    Research continued on methods to detect naturally fractured tight gas reservoirs. This report contains a seismic survey map, and reports on efforts towards a source test to select the source parameters for a 37 square mile compressional wave 3-D seismic survey. Considerations of the source tests are discussed.

  1. Gas Flow Tightly Coupled to Elastoplastic Geomechanics for Tight- and Shale-Gas Reservoirs: Material Failure and Enhanced Permeability

    DOE PAGESBeta

    Kim, Jihoon; Moridis, George J.

    2014-12-01

    We investigate coupled flow and geomechanics in gas production from extremely low permeability reservoirs such as tight and shale gas reservoirs, using dynamic porosity and permeability during numerical simulation. In particular, we take the intrinsic permeability as a step function of the status of material failure, and the permeability is updated every time step. We consider gas reservoirs with the vertical and horizontal primary fractures, employing the single and dynamic double porosity (dual continuum) models. We modify the multiple porosity constitutive relations for modeling the double porous continua for flow and geomechanics. The numerical results indicate that production of gasmore » causes redistribution of the effective stress fields, increasing the effective shear stress and resulting in plasticity. Shear failure occurs not only near the fracture tips but also away from the primary fractures, which indicates generation of secondary fractures. These secondary fractures increase the permeability significantly, and change the flow pattern, which in turn causes a change in distribution of geomechanical variables. From various numerical tests, we find that shear failure is enhanced by a large pressure drop at the production well, high Biot's coefficient, low frictional and dilation angles. Smaller spacing between the horizontal wells also contributes to faster secondary fracturing. When the dynamic double porosity model is used, we observe a faster evolution of the enhanced permeability areas than that obtained from the single porosity model, mainly due to a higher permeability of the fractures in the double porosity model. These complicated physics for stress sensitive reservoirs cannot properly be captured by the uncoupled or flow-only simulation, and thus tightly coupled flow and geomechanical models are highly recommended to accurately describe the reservoir behavior during gas production in tight and shale gas reservoirs and to smartly design

  2. Gas Flow Tightly Coupled to Elastoplastic Geomechanics for Tight- and Shale-Gas Reservoirs: Material Failure and Enhanced Permeability

    SciTech Connect

    Kim, Jihoon; Moridis, George J.

    2014-12-01

    We investigate coupled flow and geomechanics in gas production from extremely low permeability reservoirs such as tight and shale gas reservoirs, using dynamic porosity and permeability during numerical simulation. In particular, we take the intrinsic permeability as a step function of the status of material failure, and the permeability is updated every time step. We consider gas reservoirs with the vertical and horizontal primary fractures, employing the single and dynamic double porosity (dual continuum) models. We modify the multiple porosity constitutive relations for modeling the double porous continua for flow and geomechanics. The numerical results indicate that production of gas causes redistribution of the effective stress fields, increasing the effective shear stress and resulting in plasticity. Shear failure occurs not only near the fracture tips but also away from the primary fractures, which indicates generation of secondary fractures. These secondary fractures increase the permeability significantly, and change the flow pattern, which in turn causes a change in distribution of geomechanical variables. From various numerical tests, we find that shear failure is enhanced by a large pressure drop at the production well, high Biot's coefficient, low frictional and dilation angles. Smaller spacing between the horizontal wells also contributes to faster secondary fracturing. When the dynamic double porosity model is used, we observe a faster evolution of the enhanced permeability areas than that obtained from the single porosity model, mainly due to a higher permeability of the fractures in the double porosity model. These complicated physics for stress sensitive reservoirs cannot properly be captured by the uncoupled or flow-only simulation, and thus tightly coupled flow and geomechanical models are highly recommended to accurately describe the reservoir behavior during gas production in tight and shale gas reservoirs and to smartly design production

  3. 21 CFR 522.533 - Deslorelin acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Deslorelin acetate. (a) Specifications. Each implant contains 2.1 milligrams deslorelin acetate. (b) Sponsor.... One implant per mare. (ii) Indications for use. For inducing ovulation within 48 hours in...

  4. Carbon-isotopic analysis of dissolved acetate

    NASA Technical Reports Server (NTRS)

    Gelwicks, J. T.; Hayes, J. M.

    1990-01-01

    Heating of dried, acetate-containing solids together with oxalic acid dihydrate conveniently releases acetic acid for purification by gas chromatography. For determination of the carbon-isotopic composition of total acetate, the acetate-containing zone of the chromatographic effluent can be routed directly to a combustion furnace coupled to a vacuum system allowing recovery, purification, and packaging of CO2 for mass-spectrometric analysis. For analysis of methyl carbon, acetic acid can be cryogenically trapped from the chromatographic effluent, then transferred to a tube containing excess NaOH. The tube is evacuated, sealed, and heated to 500 degrees C to produce methane by pyrolysis of sodium acetate. Subsequent combustion of the methane allows determination of the 13C content at the methyl position in the parent acetate. With typical blanks, the standard deviation of single analyses is less than 0.4% for acetate samples larger than 5 micromoles. A full treatment of uncertainties is outlined.

  5. Ozone decomposition in aqueous acetate solutions

    SciTech Connect

    Sehested, K.; Holcman, J.; Bjergbakke, E.; Hart, E.J.

    1987-01-01

    The acetate radical ion reacts with ozone with a rate constant of k = (1.5 +/- 0.5) x 10Z dmT mol s . The products from this reaction are CO2, HCHO, and O2 . By subsequent reaction of the peroxy radical with ozone the acetate radical ion is regenerated through the OH radical. A chain decomposition of ozone takes place. It terminates when the acetate radical ion reacts with oxygen forming the unreactive peroxy acetate radical. The chain is rather short as oxygen is developed, as a result of the ozone consumption. The inhibiting effect of acetate on the ozone decay is rationalized by OH scavenging by acetate and successive reaction of the acetate radical ion with oxygen. Some products from the bimolecular disappearance of the peroxy acetate radicals, however, react further with ozone, reducing the effectiveness of the stabilization.

  6. The Cost Implications of Less Tight Versus Tight Control of Hypertension in Pregnancy (CHIPS Trial)

    PubMed Central

    Ahmed, Rashid J.; Gafni, Amiram; Hu, Zheng Jing; Pullenayegum, Eleanor; von Dadelszen, Peter; Rey, Evelyne; Ross, Susan; Asztalos, Elizabeth; Murphy, Kellie E.; Menzies, Jennifer; Sanchez, J. Johanna; Ganzevoort, Wessel; Helewa, Michael; Lee, Shoo K.; Lee, Terry; Logan, Alexander G.; Moutquin, Jean-Marie; Singer, Joel; Thornton, Jim G.; Welch, Ross; Magee, Laura A.

    2016-01-01

    The CHIPS randomized controlled trial (Control of Hypertension in Pregnancy Study) found no difference in the primary perinatal or secondary maternal outcomes between planned “less tight” (target diastolic 100 mm Hg) and “tight” (target diastolic 85 mm Hg) blood pressure management strategies among women with chronic or gestational hypertension. This study examined which of these management strategies is more or less costly from a third-party payer perspective. A total of 981 women with singleton pregnancies and nonsevere, nonproteinuric chronic or gestational hypertension were randomized at 14 to 33 weeks to less tight or tight control. Resources used were collected from 94 centers in 15 countries and costed as if the trial took place in each of 3 Canadian provinces as a cost-sensitivity analysis. Eleven hospital ward and 24 health service costs were obtained from a similar trial and provincial government health insurance schedules of medical benefits. The mean total cost per woman–infant dyad was higher in less tight versus tight control, but the difference in mean total cost (DM) was not statistically significant in any province: Ontario ($30 191.62 versus $24 469.06; DM $5723, 95% confidence interval, −$296 to $12 272; P=0.0725); British Columbia ($30 593.69 versus $24 776.51; DM $5817; 95% confidence interval, −$385 to $12 349; P=0.0725); or Alberta ($31 510.72 versus $25 510.49; DM $6000.23; 95% confidence interval, −$154 to $12 781; P=0.0637). Tight control may benefit women without increasing risk to neonates (as shown in the main CHIPS trial), without additional (and possibly lower) cost to the healthcare system. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01192412. PMID:27550914

  7. Air Tightness of US Homes: Model Development

    SciTech Connect

    Sherman, Max H.

    2006-05-01

    Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses that database to develop a model for estimating air leakage as a function of climate, building age, floor area, building height, floor type, energy-efficiency and low-income designations. The model developed can be used to estimate the leakage distribution of populations of houses.

  8. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    1999-06-01

    Building upon the partitioning of the Greater Green River Basin (GGRB) that was conducted last quarter, the goal of the work this quarter has been to conclude evaluation of the Stratos well and the prototypical Green River Deep partition, and perform the fill resource evaluation of the Upper Cretaceous tight gas play, with the goal of defining target areas of enhanced natural fracturing. The work plan for the quarter of November 1-December 31, 1998 comprised four tasks: (1) Evaluation of the Green River Deep partition and the Stratos well and examination of potential opportunity for expanding the use of E and P technology to low permeability, naturally fractured gas reservoirs, (2) Gas field studies, and (3) Resource analysis of the balance of the partitions.

  9. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and....1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3 or C2H3O2Na·3H2O, CAS Reg. No. 6131-90-4) is the sodium salt of acetic acid and occurs naturally in plant and animal tissues....

  10. Recent resource assessments of tight gas reservoirs

    SciTech Connect

    Spencer, C.W.

    1984-04-01

    Two fairly recent estimates of natural gas recoverable from tight gas reservoirs in the US have been made. One was prepared in 1978, by Lewin and Associates for DOE (US Department of Energy) and the second was made by the NPC (National Petroleum Council) in 1980. Lewin estimated about 200 tcf is recoverable from the 14 most favorable regions in the US. The NPC estimated that about 500 tcf is recoverable from the entire onshore US. These studies involved a careful analysis of available data; however, both studies excluded large areas and great thicknesses of rock strata from their resource data base. The reasons for these exclusions were mostly lack of good well control and not absence of gas potential. Therefore, both assessments were conservative and the potential recoverable resource is probably much larger than even the 500 tcf estimated by the NPC. Unfortunately present-day technology is not able to consistently identify, stimulate, and produce large volumes of gas from lenticular and (or) deep tight reservoirs. The NPC recognized these problems and listed many research topics and programs, in their report, that should be undertaken to increase the amount of recoverable gas. A few of the more important informational needs are: (1) better methods to predict geometry of reservoirs, (2) improvement of log interpretation, (3) better prediction of natural fracture systems, (4) control of, and prediction of, hydraulic fracture height, length, and orientation, (5) elimination of formation damage, and (6) development of innovative reservoir stimulation methods. DOE has supported a number of research efforts directed toward solving many of these problems.

  11. Kinetics of the Methanogenic Fermentation of Acetate

    PubMed Central

    Fukuzaki, Satoshi; Nishio, Naomichi; Nagai, Shiro

    1990-01-01

    Inhibition of the fermentation of acetate to methane and carbon dioxide by acetate was analyzed with an acetate-acclimatized sludge and with Methanosarcina barkeri Fusaro under mesophilic conditions. A second-order substrate inhibition model, qch4 = qmS/[Ks + S + (S2/Ki)], where S was the concentration of undissociated acetic acid, not ionized acetic acid, could be applicable in both cases. The analysis resulted in substrate saturation constants, Ks, of 4.0 μM for the acclimatized sludge and 104 μM for M. barkeri. The threshold concentrations of undissociated acetic acid when no further acetate utilization was observed were 0.078 μM (pH 7.50) for the acclimatized sludge and 4.43 μM (pH 7.45) for M. barkeri. These kinetic results suggested that the concentration of undissociated acetic acid became a key factor governing the actual threshold acetate concentration for acetate utilization and that the acclimatized sludge in which Methanothrix spp. appeared dominant could utilize acetate better and survive at a lower concentration of undissociated acetic acid than could M. barkeri. Images PMID:16348323

  12. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  13. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  14. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  15. 21 CFR 522.2476 - Trenbolone acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  16. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  17. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  18. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acetic acid. 184.1005 Section 184.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD....1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It...

  19. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  20. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  1. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  2. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  3. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  4. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  5. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  6. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  7. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  8. Acet-oxy-γ-valerolactone.

    PubMed

    Tristram, Cameron; Gainsford, Graeme J; Hinkley, Simon

    2013-06-01

    Levulinyl cellulose esters have been produced as an effective renewable binder for architectural coatings. The title compound, C7H10O4 (systematic name: 2-methyl-5-oxo-tetra-hydro-furan-2-yl acetate), assigned as the esterifying species, was isolated and crystallized to confirm the structure. In the crystal, the mol-ecules pack in layers parallel to (102) utilizing weak C-H⋯O inter-actions. PMID:23795112

  9. Experiments on Exhaust Noise of Tightly Integrated Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Bridges, James E.; Brown, Clifford A.; Bozak, Richard F.

    2014-01-01

    A wide-ranging series of tests have been completed that seek to map the effects of installation, including jet by jet interaction effects, on exhaust noise from various nozzles in forward flight. The primary data was far-field acoustic spectral directivity. The goals of the test series were (i) to generate enough data for empirical models of the different effects, and (ii) to provide data for advanced computational noise predictions methods applied to simplified yet realistic configurations. Data is presented that demonstrate several checks on data quality and that provide an overview of trends observed to date. Among the findings presented here: (i) Data was repeatable between jet rigs for single nozzles with and without surfaces to within +/- 0.5 dB. (ii) The presence of a second jet caused a strong reduction of the summed noise in the plane of the two plumes and an increase over the expected source doubling in most other azimuthal planes. (iii) The impact of the second jet was reduced when the jets were unheated. (iv) The impact of adding a second isolated rectangular jet was relatively independent of the nozzle aspect ratio up to aspect ratio 8:1. (v) Forward flight had similar impact on a high aspect ratio (8:1) jet as on an axisymmetric jet, except at the peak noise angle where the impact was less. (vi) The effect of adding a second round jet to a tightly integrated nozzle where the nozzle lip was less than a diameter from the surface was very dependent upon the length of the surface downstream of the nozzle. (vii) When the nozzles were rectangular and tightly integrated with the airframe surface the impact of a second jet was very dependent upon how close together the two jets were. This paper serves as an overview of the test; other papers presented in the same conference will give more detailed analysis of the results.

  10. Efficient self-consistency for magnetic tight binding

    NASA Astrophysics Data System (ADS)

    Soin, Preetma; Horsfield, A. P.; Nguyen-Manh, D.

    2011-06-01

    Tight binding can be extended to magnetic systems by including an exchange interaction on an atomic site that favours net spin polarisation. We have used a published model, extended to include long-ranged Coulomb interactions, to study defects in iron. We have found that achieving self-consistency using conventional techniques was either unstable or very slow. By formulating the problem of achieving charge and spin self-consistency as a search for stationary points of a Harris-Foulkes functional, extended to include spin, we have derived a much more efficient scheme based on a Newton-Raphson procedure. We demonstrate the capabilities of our method by looking at vacancies and self-interstitials in iron. Self-consistency can indeed be achieved in a more efficient and stable manner, but care needs to be taken to manage this. The algorithm is implemented in the code PLATO. Program summaryProgram title:PLATO Catalogue identifier: AEFC_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFC_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 228 747 No. of bytes in distributed program, including test data, etc.: 1 880 369 Distribution format: tar.gz Programming language: C and PERL Computer: Apple Macintosh, PC, Unix machines Operating system: Unix, Linux, Mac OS X, Windows XP Has the code been vectorised or parallelised?: Yes. Up to 256 processors tested RAM: Up to 2 Gbytes per processor Classification: 7.3 External routines: LAPACK, BLAS and optionally ScaLAPACK, BLACS, PBLAS, FFTW Catalogue identifier of previous version: AEFC_v1_0 Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 2616 Does the new version supersede the previous version?: Yes Nature of problem: Achieving charge and spin self-consistency in magnetic tight binding can be very

  11. Tightly Coupled Multiphysics Algorithm for Pebble Bed Reactors

    SciTech Connect

    HyeongKae Park; Dana Knoll; Derek Gaston; Richard Martineau

    2010-10-01

    We have developed a tightly coupled multiphysics simulation tool for the pebble-bed reactor (PBR) concept, a type of Very High-Temperature gas-cooled Reactor (VHTR). The simulation tool, PRONGHORN, takes advantages of the Multiphysics Object-Oriented Simulation Environment library, and is capable of solving multidimensional thermal-fluid and neutronics problems implicitly with a Newton-based approach. Expensive Jacobian matrix formation is alleviated via the Jacobian-free Newton-Krylov method, and physics-based preconditioning is applied to minimize Krylov iterations. Motivation for the work is provided via analysis and numerical experiments on simpler multiphysics reactor models. We then provide detail of the physical models and numerical methods in PRONGHORN. Finally, PRONGHORN's algorithmic capability is demonstrated on a number of PBR test cases.

  12. Reduction of aerobic acetate production by Escherichia coli.

    PubMed Central

    Farmer, W R; Liao, J C

    1997-01-01

    Acetate excretion by Escherichia coli during aerobic growth on glucose is a major obstacle to enhanced recombinant protein production. We report here that the fraction of carbon flux through the anaplerotic pathways is one of the factors influencing acetate excretion. Flux analysis of E. coli central metabolic pathways predicts that increasing the fraction of carbon flux through the phosphoenolpyruvate carboxylase (PPC) pathway and the glyoxylate bypass reduces acetate production. We tested this prediction by overexpressing PPC and deregulating the glyoxylate bypass by using a fadR strain. Results show that the acetate yield by the fadR strain with PPC overexpression is decreased more than fourfold compared to the control, while the biomass yield is relatively unaffected. Apparently, the fraction of carbon flux through the anaplerotic pathways is one of the factors that influence acetate excretion. These results confirm the prediction of our flux analysis and further suggest that E. coli is not fully optimized for efficient utilization of glucose. PMID:9251207

  13. Tight Junction Properties Change During Epidermis Development

    PubMed Central

    Celli, A; Zhai, Y; Jiang, YJ; Crumrine, D; Elias, PM; Feingold, KR; Mauro, TM

    2012-01-01

    In terrestrial animals, the epidermal barrier transitions from covering an organism suspended in a liquid environment in utero, to protecting a terrestrial animal postnatally from air and environmental exposure. Tight junctions (TJ) are essential for establishing the epidermal permeability barrier during embryonic development, and modulate normal epidermal development and barrier functions postnatally. We now report that TJ function, as well as claudin-1 and occludin expression, change in parallel during late epidermal development. Specifically, TJ block the paracellular movement of Lanthanum (La3+) early in rat in vivo prenatal epidermal development, at gestational days 18–19, with concurrent upregulation of claudin-1 and occludin. TJ then become more permeable to ions and water as the fetus approaches parturition, concomitant with development of the lipid epidermal permeability barrier, at days 20–21. This sequence is recapitulated in cultured human epidermal equivalents (HEE), as assessed both by ultrastructural studies comparing permeation of large and small molecules, and by the standard electrophysiologic parameter of resistance (R), suggesting further that this pattern of development is intrinsic to mammalian epidermal development. These findings demonstrate that the role of TJ changes during epidermal development, and further suggest that the TJ-based and lipid-based epidermal permeability barriers are interdependent. PMID:22882565

  14. Functional analysis of tight junction organization.

    PubMed

    DiBona, D R

    1985-01-01

    The functional basis of tight junction design has been examined from the point of view that this rate-limiting barrier to paracellular transport is a multicompartment system. Review of the osmotic sensitivity of these structures points to the need for this sort of analysis for meaningful correlation of structure and function under a range of conditions. A similar conclusion is drawn with respect to results from voltage-clamping protocols where reversal of spontaneous transmural potential difference elicits parallel changes in both structure and function in much the same way as does reversal of naturally occurring osmotic gradients. In each case, it becomes necessary to regard the junction as a functionally polarized structure to account for observations of its rectifying properties. Lastly, the details of experimentally-induced junction deformation are examined in light of current theories of its organization; arguments are presented in favor of the view that the primary components of intramembranous organization (as viewed with freeze-fracture techniques) are lipidic rather than proteinaceous. PMID:4088839

  15. Enterocytes’ tight junctions: From molecules to diseases

    PubMed Central

    Assimakopoulos, Stelios F; Papageorgiou, Ismini; Charonis, Aristidis

    2011-01-01

    Tight junctions (TJs) are structures between cells where cells appear in the closest possible contact. They are responsible for sealing compartments when epithelial sheets are generated. They regulate the permeability of ions, (macro) molecules and cells via the paracellular pathway. Their structure at the electron microscopic level has been well known since the 1970s; however, only recently has their macromolecular composition been revealed. This review first examines the major macromolecular components of the TJs (occludin, claudins, junctional adhesion molecule and tricellulin) and then the associated macromolecules at the intracellular plaque [zonula occludens (ZO)-1, ZO-2, ZO-3, AF-6, cingulin, 7H6]. Emphasis is given to their interactions in order to begin to understand the mode of assembly of TJs. The functional significance of TJs is detailed and several mechanisms and factors involved are discussed briefly. Emphasis is given to the role of intestinal TJs and the alterations observed or speculated in diverse disease states. Specifically, intestinal TJs may exert a pathogenetic role in intestinal (inflammatory bowel disease, celiac disease) and extraintestinal diseases (diabetes type 1, food allergies, autoimmune diseases). Additionally, intestinal TJs may be secondarily disrupted during the course of diverse diseases, subsequently allowing the bacterial translocation phenomenon and promoting the systemic inflammatory response, which is often associated with clinical deterioration. The major questions in the field are highlighted. PMID:22184542

  16. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    1999-04-30

    In March, work continued on characterizing probabilities for determining natural fracturing associated with the GGRB for the Upper Cretaceous tight gas plays. Structural complexity, based on potential field data and remote sensing data was completed. A resource estimate for the Frontier and Mesa Verde play was also completed. Further, work was also conducted to determine threshold economics for the play based on limited current production in the plays in the Wamsutter Ridge area. These analyses culminated in a presentation at FETC on 24 March 1999 where quantified natural fracture domains, mapped on a partition basis, which establish ''sweet spot'' probability for natural fracturing, were reviewed. That presentation is reproduced here as Appendix 1. The work plan for the quarter of January 1, 1999--March 31, 1999 comprised five tasks: (1) Evaluation of the GGRB partitions for structural complexity that can be associated with natural fractures, (2) Continued resource analysis of the balance of the partitions to determine areas with higher relative gas richness, (3) Gas field studies, (4) Threshold resource economics to determine which partitions would be the most prospective, and (5) Examination of the area around the Table Rock 4H well.

  17. 18 CFR 270.305 - Determination of tight formation areas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... for tight formation designation, the stabilized production rate of natural gas, against atmospheric pressure, of wells completed for production in such portion of such formation, without stimulation, is...

  18. 18 CFR 270.305 - Determination of tight formation areas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... for tight formation designation, the stabilized production rate of natural gas, against atmospheric pressure, of wells completed for production in such portion of such formation, without stimulation, is...

  19. Ischemic preconditioning enhances integrity of coronary endothelial tight junctions

    SciTech Connect

    Li, Zhao; Jin, Zhu-Qiu

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer Cardiac tight junctions are present between coronary endothelial cells. Black-Right-Pointing-Pointer Ischemic preconditioning preserves the structural and functional integrity of tight junctions. Black-Right-Pointing-Pointer Myocardial edema is prevented in hearts subjected to ischemic preconditioning. Black-Right-Pointing-Pointer Ischemic preconditioning enhances translocation of ZO-2 from cytosol to cytoskeleton. -- Abstract: Ischemic preconditioning (IPC) is one of the most effective procedures known to protect hearts against ischemia/reperfusion (IR) injury. Tight junction (TJ) barriers occur between coronary endothelial cells. TJs provide barrier function to maintain the homeostasis of the inner environment of tissues. However, the effect of IPC on the structure and function of cardiac TJs remains unknown. We tested the hypothesis that myocardial IR injury ruptures the structure of TJs and impairs endothelial permeability whereas IPC preserves the structural and functional integrity of TJs in the blood-heart barrier. Langendorff hearts from C57BL/6J mice were prepared and perfused with Krebs-Henseleit buffer. Cardiac function, creatine kinase release, and myocardial edema were measured. Cardiac TJ function was evaluated by measuring Evans blue-conjugated albumin (EBA) content in the extravascular compartment of hearts. Expression and translocation of zonula occludens (ZO)-2 in IR and IPC hearts were detected with Western blot. A subset of hearts was processed for the observation of ultra-structure of cardiac TJs with transmission electron microscopy. There were clear TJs between coronary endothelial cells of mouse hearts. IR caused the collapse of TJs whereas IPC sustained the structure of TJs. IR increased extravascular EBA content in the heart and myocardial edema but decreased the expression of ZO-2 in the cytoskeleton. IPC maintained the structure of TJs. Cardiac EBA content and edema were reduced in IPC hearts. IPC

  20. US production of natural gas from tight reservoirs

    SciTech Connect

    Not Available

    1993-10-18

    For the purposes of this report, tight gas reservoirs are defined as those that meet the Federal Energy Regulatory Commission`s (FERC) definition of tight. They are generally characterized by an average reservoir rock permeability to gas of 0.1 millidarcy or less and, absent artificial stimulation of production, by production rates that do not exceed 5 barrels of oil per day and certain specified daily volumes of gas which increase with the depth of the reservoir. All of the statistics presented in this report pertain to wells that have been classified, from 1978 through 1991, as tight according to the FERC; i.e., they are ``legally tight`` reservoirs. Additional production from ``geologically tight`` reservoirs that have not been classified tight according to the FERC rules has been excluded. This category includes all producing wells drilled into legally designated tight gas reservoirs prior to 1978 and all producing wells drilled into physically tight gas reservoirs that have not been designated legally tight. Therefore, all gas production referenced herein is eligible for the Section 29 tax credit. Although the qualification period for the credit expired at the end of 1992, wells that were spudded (began to be drilled) between 1978 and May 1988, and from November 5, 1990, through year end 1992, are eligible for the tax credit for a subsequent period of 10 years. This report updates the EIA`s tight gas production information through 1991 and considers further the history and effect on tight gas production of the Federal Government`s regulatory and tax policy actions. It also provides some high points of the geologic background needed to understand the nature and location of low-permeability reservoirs.

  1. Claudins and the Modulation of Tight Junction Permeability

    PubMed Central

    Günzel, Dorothee

    2013-01-01

    Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction permeability. This review summarizes our current knowledge of this large protein family and discusses recent advances in our understanding of their structure and physiological functions. PMID:23589827

  2. Understanding Palladium Acetate from a User Perspective.

    PubMed

    Carole, William A; Colacot, Thomas J

    2016-06-01

    The behavior of palladium acetate is reviewed with respect to its synthesis, characterization, structure (in both solution and solid state), and activation pathways. In addition, comparisons of catalytic activities between pure palladium acetate and two common byproducts, Pd3 (OAc)5 (NO2 ) and polymeric [Pd(OAc)2 ]n , typically present in commercially available material are reviewed. Hence, this minireview serves as a concise guide for the users of palladium acetate from both academia and industry. PMID:27125630

  3. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  4. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  5. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  6. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  7. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  8. Systematic Construction of Real Lapped Tight Frame Transforms

    PubMed Central

    Sandryhaila, Aliaksei; Chebira, Amina; Milo, Christina; Kovčcević, Jelena; Püschel, Markus

    2010-01-01

    We present a constructive algorithm for the design of real lapped equal-norm tight frame transforms. These transforms can be efficiently implemented through filter banks and have recently been proposed as a redundant counterpart to lapped orthogonal transforms, as well as an infinite-dimensional counterpart to harmonic tight frames. The proposed construction consists of two parts: First, we design a large class of new real lapped orthogonal transforms derived from submatrices of the discrete Fourier transform. Then, we seed these to obtain real lapped tight frame transforms corresponding to tight, equal-norm frames. We identify those frames that are maximally robust to erasures, and show that our construction leads to a large class of new lapped orthogonal transforms as well as new lapped tight frame transforms. PMID:20607116

  9. Positron scattering from vinyl acetate

    NASA Astrophysics Data System (ADS)

    Chiari, L.; Zecca, A.; Blanco, F.; García, G.; Brunger, M. J.

    2014-09-01

    Using a Beer-Lambert attenuation approach, we report measured total cross sections (TCSs) for positron scattering from vinyl acetate (C4H6O2) in the incident positron energy range 0.15-50 eV. In addition, we also report an independent atom model with screening corrected additivity rule computation results for the TCSs, differential and integral elastic cross sections, the positronium formation cross section and inelastic integral cross sections. The energy range of these calculations is 1-1000 eV. While there is a reasonable qualitative correspondence between measurement and calculation for the TCSs, in terms of the energy dependence of those cross sections, the theory was found to be a factor of ˜2 larger in magnitude at the lower energies, even after the measured data were corrected for the forward angle scattering effect.

  10. Extractive fermentation of acetic acid

    SciTech Connect

    Busche, R.M.

    1991-12-31

    In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

  11. US Geological Survey publications on western tight gas reservoirs

    SciTech Connect

    Krupa, M.P.; Spencer, C.W.

    1989-02-01

    This bibliography includes reports published from 1977 through August 1988. In 1977 the US Geological Survey (USGS), in cooperation with the US Department of Energy's, (DOE), Western Gas Sands Research program, initiated a geological program to identify and characterize natural gas resources in low-permeability (tight) reservoirs in the Rocky Mountain region. These reservoirs are present at depths of less than 2,000 ft (610 m) to greater than 20,000 ft (6,100 m). Only published reports readily available to the public are included in this report. Where appropriate, USGS researchers have incorporated administrative report information into later published studies. These studies cover a broad range of research from basic research on gas origin and migration to applied studies of production potential of reservoirs in individual wells. The early research included construction of regional well-log cross sections. These sections provide a basic stratigraphic framework for individual areas and basins. Most of these sections include drill-stem test and other well-test data so that the gas-bearing reservoirs can be seen in vertical and areal dimensions. For the convenience of the reader, the publications listed in this report have been indexed by general categories of (1) authors, (2) states, (3) geologic basins, (4) cross sections, (5) maps (6) studies of gas origin and migration, (7) reservoir or mineralogic studies, and (8) other reports of a regional or specific topical nature.

  12. Real-time kinematic surveying using tightly-coupled GPS and ultra-wideband ranging

    NASA Astrophysics Data System (ADS)

    Macgougan, Glenn D.

    Ultra-wideband (UWB) ranging radios, an emerging technology that offers precise, short distance, range measurements are investigated as a method to augment carrier-phase GPS positioning. This thesis begins with a discussion of radio-frequency based methods of augmenting high precision GPS and proposes to utilize UWB ranging technology in a tightly-coupled GPS and UWB position estimation filter. This thesis then provides an overview of UWB in the context of ranging applications and assesses the precision and accuracy of UWB ranging from both a theoretical perspective and a practical perspective using real data. Two types of commercially available UWB ranging radios are introduced which are used in testing. Actual ranging accuracy is assessed from line-of-sight testing in benign signal conditions and in outdoor testing with line-of-sight obstructions and strong reflection sources. A tightly-coupled GPS and UWB real-time kinematic (RTK) estimation method is developed and the performance of the system is evaluated in static and kinematic testing. The results of static testing show that the integrated solution provides better accuracy, better ability to resolve integer ambiguities and enhanced fixed ambiguity solution availability compared with GPS alone. The results of kinematic testing demonstrate that UWB errors can be successfully estimated in a real-time filter. In static and kinematic testing in a degraded GPS environment created by artificially inducing a 40° satellite elevation mask, subdecimetre accuracy was maintained. The tightly-coupled system is also tested to survey several external corner points of an eight story building. The tightly-coupled solution is compared to GPS-only, UWB-only, and loosely-coupled solutions. Sub-metre level solutions are maintained using tight-coupling in conditions where the solutions from the other three approaches are either unavailable or unreliable. The thesis also provides a novel and efficient method for deploying UWB

  13. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  14. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  15. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  16. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts...

  17. Manufacturing Ethyl Acetate From Fermentation Ethanol

    NASA Technical Reports Server (NTRS)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  18. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl acetate. 173.228 Section 173.228 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  19. Development of Acetic Acid Removal Technology for the UREX+Process

    SciTech Connect

    Robert M. Counce; Jack S. Watson

    2009-06-30

    It is imperative that acetic acid is removed from a waste stream in the UREX+process so that nitric acid can be recycled and possible interference with downstreatm steps can be avoidec. Acetic acid arises from acetohydrozamic acid (AHA), and is used to suppress plutonium in the first step of the UREX+process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of acetic acid. The tributyl phosphage (TBP)-dodecane diluent, used in both UREX and NPEX, was determined to be a solvent system that gave sufficient distribution coefficients for acetic acid in addition to a high separation factor from nitric acid.

  20. Effects of acetic acid on light scattering from cells

    PubMed Central

    Marina, Oana C.; Sanders, Claire K.

    2012-01-01

    Abstract. Acetic acid has been used for decades as an aid for the detection of precancerous cervical lesions, and the use of acetic acid is being investigated in several other tissues. Nonetheless, the mechanism of acetowhitening is unclear. This work tests some of the hypotheses in the literature and measures changes in light scattering specific to the nucleus and the cytoplasm. Wide angle side scattering from both the nucleus and the cytoplasm increases with acetic application to tumorigenic cells, with the increase in nuclear scattering being greater. In one cell line, the changes in nuclear scattering are likely due to an increase in number or scattering efficiency of scattering centers smaller than the wavelength of excitation light. There are likely several cellular changes that cause acetowhitening and the cellular changes may differ with cell type. These results should lead to a better understanding of acetowhitening and potentially the development of adjunct techniques to improve the utility of acetic acid application. For the well-studied case of cervical tissue, acetowhitening has been shown to be sensitive, but not specific for oncogenic changes needing treatment. PMID:23224185

  1. A remotely operated serial sampler for collecting gas-tight fluid samples

    NASA Astrophysics Data System (ADS)

    Wu, Shi-jun; Yang, Can-jun; Ding, Kang; Tan, Chun-yang

    2015-10-01

    This paper describes the design, construction and preliminary test results for a gas-tight serial sampler intended to be deployed at seafloor for long-term operation to take time-series fluid samples from deep-sea environments such as cold seeps, water column and hydrothermal vents. The serial sampler is a modular system that is based on independent and identical sampling modules, which are designed to collect six 160 ml gas-tight fluid samples maintained at high pressure to a depth of 4000 meters. With two working modes, the sampler can be deployed either with seafloor cabled observatory for remote control or as a stand-alone device for autonomous operation. A prototype of the instrument has been constructed and tested on the MARS cabled observatory for two months. The laboratory and field tests proved the success of the design and construction of the serial sampler, and indicated the potential for future ocean sciences.

  2. An Evaluation of Retentive Ability and Deformation of Acetal Resin and Cobalt-Chromium Clasps

    PubMed Central

    Meenakshi, A.; Gupta, Ranjana; Bharti, Vinay; Sriramaprabu, G.

    2016-01-01

    Aim To compare the retentive ability and deformation of Acetal resin with Cobalt-Chromium clasps via Insertion Removal apparatus after subjecting them to stimulate clinical use. Materials and Methods Materials used for this study are commercially available Cobalt-Chromium alloy namely Wironit, Bego, Germany and Acetal resin namely Biodentaplast, Bredent, Germany. The test samples were divided into two major groups based on the type of materials used in the study. Each major group is further subdivided into two sub groups based on the retentive undercut depths used to engage the clasps. So a total of 20 specimens were prepared, comprising of 5 specimens in each sub group. Then the specimens were tested for retention force and deformation. Results The results of this study indicate that acetal resin clasps are resistant to deformation and may offer a clinical advantage over the conventional metal clasps. The retentive force of acetal resin clasps did not decrease over the cycling periods. This would be attributed to the resilient nature of acetal resin. Under the conditions of the present study cobalt chromium clasps lost retentive force within 730 cycles of placement and removal and continued to lose retentive force during the remaining test period. Conclusion This invitro study demonstrated that retentive force of cobalt chromium clasp is superior to that of Acetal resin for removable partial dentures. As acetal resin clasps exhibits greater flexibility and long term retentive resiliency, it can be used for removable partial dentures where aesthetics or periodontal health is a primary concern. PMID:26894173

  3. Ethanol-induced activation of adenine nucleotide turnover. Evidence for a role of acetate

    SciTech Connect

    Puig, J.G.; Fox, I.H.

    1984-09-01

    Consumption of alcohol causes hyperuricemia by decreasing urate excretion and increasing its production. Our previous studies indicate that ethanol administration increases uric acid production by increasing ATP degradation to uric acid precursors. To test the hypothesis that ethanol-induced increased urate production results from acetate metabolism and enhanced adenosine triphosphate turnover, we gave intravenous sodium acetate, sodium chloride and ethanol (0.1 mmol/kg per min for 1 h) to five normal subjects. Acetate plasma levels increased from 0.04 +/- 0.01 mM (mean +/- SE) to peak values of 0.35 +/- 0.07 mM and to 0.08 +/- 0.01 mM during acetate and ethanol infusions, respectively. Urinary oxypurines increased to 223 +/- 13% and 316 +/- 44% of the base-line values during acetate and ethanol infusions, respectively. Urinary radioactivity from the adenine nucleotide pool labeled with (8-14C) adenine increased to 171 +/- 27% and to 128 +/- 8% of the base-line values after acetate and ethanol infusions. These data indicate that both ethanol and acetate increase purine nucleotide degradation by enhancing the turnover of the adenine nucleotide pool. They support the hypothesis that acetate metabolism contributes to the increased production of urate associated with ethanol intake.

  4. Heavy ion beam probe systems for tight aspect ratio tokamaks

    SciTech Connect

    Melnikov, A.V.; Zimeleva, L.G.; Krupnik, L.I.; Nedzelskij, I.S.; Trofimenko, Y.V.; Minaev, V.B.

    1997-01-01

    We discuss the specific features of the application of heavy ion beam probe (HIBP) systems to tight aspect ratio tokamaks. We present and compare the HIBP projects for the TUMAN-3, GLOBUS, and COMPASS, where the inner part of the plasma is not available for regular chord diagnostics, so the HIBP becomes very desirable. All existing tight aspect ratio facilities and projects have a low (less than 1.9 T) toroidal field that requires a comparatively low beam energy range. The natural elongation and triangularity in tight aspect ratio tokamaks require an accurate calculation of the three-dimensional magnetic field for probing optimization. In comparison with traditional tokamaks, the detector grids have a wider energy interval. In general, the trajectories and detector grids for tight aspect ratio tokamaks become similar to the stellarator ones. Traditional and new probing schemes are suggested and discussed. {copyright} {ital 1997 American Institute of Physics.}

  5. Western tight gas sands advanced logging workshop proceedings

    SciTech Connect

    Jennings, J B; Carroll, Jr, H B

    1982-04-01

    An advanced logging research program is one major aspect of the Western Tight Sands Program. Purpose of this workshop is to help BETC define critical logging needs for tight gas sands and to allow free interchange of ideas on all aspects of the current logging research program. Sixteen papers and abstracts are included together with discussions. Separate abstracts have been prepared for the 12 papers. (DLC)

  6. Results from tight and loose coupled multiphysics in nuclear fuels performance simulations using BISON

    SciTech Connect

    Novascone, S. R.; Spencer, B. W.; Andrs, D.; Williamson, R. L.; Hales, J. D.; Perez, D. M.

    2013-07-01

    The behavior of nuclear fuel in the reactor environment is affected by multiple physics, most notably heat conduction and solid mechanics, which can have a strong influence on each other. To provide credible solutions, a fuel performance simulation code must have the ability to obtain solutions for each of the physics, including coupling between them. Solution strategies for solving systems of coupled equations can be categorized as loosely-coupled, where the individual physics are solved separately, keeping the solutions for the other physics fixed at each iteration, or tightly coupled, where the nonlinear solver simultaneously drives down the residual for each physics, taking into account the coupling between the physics in each nonlinear iteration. In this paper, we compare the performance of loosely and tightly coupled solution algorithms for thermomechanical problems involving coupled thermal and mechanical contact, which is a primary source of interdependence between thermal and mechanical solutions in fuel performance models. The results indicate that loosely-coupled simulations require significantly more nonlinear iterations, and may lead to convergence trouble when the thermal conductivity of the gap is too small. We also apply the tightly coupled solution strategy to a nuclear fuel simulation of an experiment in a test reactor. Studying the results from these simulations indicates that perhaps convergence for either approach may be problem dependent, i.e., there may be problems for which a loose coupled approach converges, where tightly coupled won't converge and vice versa. (authors)

  7. Results from Tight and Loose Coupled Multiphysics in Nuclear Fuels Performance Simulations using BISON

    SciTech Connect

    S. R. Novascone; B. W. Spencer; D. Andrs; R. L. Williamson; J. D. Hales; D. M. Perez

    2013-05-01

    The behavior of nuclear fuel in the reactor environment is affected by multiple physics, most notably heat conduction and solid mechanics, which can have a strong influence on each other. To provide credible solutions, a fuel performance simulation code must have the ability to obtain solutions for each of the physics, including coupling between them. Solution strategies for solving systems of coupled equations can be categorized as loosely-coupled, where the individual physics are solved separately, keeping the solutions for the other physics fixed at each iteration, or tightly coupled, where the nonlinear solver simultaneously drives down the residual for each physics, taking into account the coupling between the physics in each nonlinear iteration. In this paper, we compare the performance of loosely and tightly coupled solution algorithms for thermomechanical problems involving coupled thermal and mechanical contact, which is a primary source of interdependence between thermal and mechanical solutions in fuel performance models. The results indicate that loosely-coupled simulations require significantly more nonlinear iterations, and may lead to convergence trouble when the thermal conductivity of the gap is too small. We also apply the tightly coupled solution strategy to a nuclear fuel simulation of an experiment in a test reactor. Studying the results from these simulations indicates that perhaps convergence for either approach may be problem dependent, i.e., there may be problems for which a loose coupled approach converges, where tightly coupled won’t converge and vice versa.

  8. Acetate dialysate versus bicarbonate dialysate: a continuing controversy.

    PubMed

    Diamond, S M; Henrich, W L

    1987-01-01

    The use of bicarbonate dialysate as the buffer during routine dialysis is growing. This discussion reviews several of the comparative trials in which bicarbonate and acetate buffers have been tested. Effects of the two buffers on BP, cardiac function, and pulmonary performance are discussed. Costs of the two systems are also compared. Patients who seem most likely to benefit from bicarbonate dialysate include those with a reduced muscle mass in whom a high sodium dialysate has not prevented hypotension. PMID:3028133

  9. Theophylline-7-acetic acid: lack of absorption and therapeutic effectiveness.

    PubMed Central

    Fleetham, J A; Owen, J A; May, B; Munt, P W; Nakatsu, K

    1979-01-01

    A double-blind cross-over trial was conducted to evaluate the effectiveness of oral theophylline-7-acetic acid (T7AA) in 13 asthmatic patients. Pulmonary function tests showed no difference between T7AA and placebo. No T7AA or theophylline was found in the sera of these patients or of healthy volunteers who took T7AA tablets or syrup. PMID:388714

  10. Tightness-looseness across the 50 united states.

    PubMed

    Harrington, Jesse R; Gelfand, Michele J

    2014-06-01

    This research demonstrates wide variation in tightness-looseness (the strength of punishment and degree of latitude/permissiveness) at the state level in the United States, as well as its association with a variety of ecological and historical factors, psychological characteristics, and state-level outcomes. Consistent with theory and past research, ecological and man-made threats--such as a higher incidence of natural disasters, greater disease prevalence, fewer natural resources, and greater degree of external threat--predicted increased tightness at the state level. Tightness is also associated with higher trait conscientiousness and lower trait openness, as well as a wide array of outcomes at the state level. Compared with loose states, tight states have higher levels of social stability, including lowered drug and alcohol use, lower rates of homelessness, and lower social disorganization. However, tight states also have higher incarceration rates, greater discrimination and inequality, lower creativity, and lower happiness relative to loose states. In all, tightness-looseness provides a parsimonious explanation of the wide variation we see across the 50 states of the United States of America. PMID:24843116

  11. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    1996-09-30

    The focus of this report was on preparing data and modules for Piceance Basin-wide fracture prediction. A review of the geological data input and automated history reconstruction approach was made. Fluid pressure data analysis and preliminary basin simulations were carried out. These activities are summarized briefly below and reviewed in more detail in Appendices A-E. Appendix D is a review of the fluid pressure data and its implications for compartmentation. Preliminary fracture prediction computations on generic basins are presented in Appendix E; these were carried out as part of our code testing activities. The results of these two Appendices are the beginning of what will be the basis of the model testing; fluid pressures are directly comparable with the model predictions and are a key element of fracture nucleation and presentation. We summarize the tectonic and sedimentary history of the Piceance Basin based on our automated history reconstruction and published interpretations. The narrative and figures provide the basic material we have quantified for our CIRF.B basin simulator input. This data supplements our existing well data interpretation approach. It provides an independent check of the automated sedimentary/subsidence history reconstruction module. Fluid pressure data was gathered and analyzed. This data serves two functions. Fluid pressure distribution across the basin provides a quantitative test as it is a direct prediction of CIRF.B. Furthermore, fluid pressure modifies effective stress. It thereby enters fracture nucleation criteria and fracture extension rate and aperture laws. The pressure data is presented in Appendix Din terms of overpressure maps and isosurfaces.

  12. Naturally fractured tight gas reservoir detection optimization

    SciTech Connect

    1998-09-30

    The work plan for the quarter of October 1, 1997--December 31, 1997 consisted of two tasks: (1) Present results of Rulison field test at various conferences, seminars, and to Barrett Resources and Snyder Oil Co. and (2) Continue work into developing a predictive quantitative method for locating fault-related natural fractures. The first task was completed during this reporting period. The second task continues the beginning of quantitative fracture mechanics analysis of the geologic processes that are involved for the development of fault-related natural fractures. The goal of this work is to develop a predictive capability of locating natural fractures prior to drilling.

  13. The pharmacology of nomegestrol acetate.

    PubMed

    Ruan, Xiangyan; Seeger, Harald; Mueck, Alfred O

    2012-04-01

    Nomegestrol acetate (NOMAC) is a 19-norprogesterone derivative with high biological activity at the progesterone receptor, a weak anti-androgenic effect, but with no binding to estrogen, glucocorticoid or mineralocorticoid receptors. At dosages of 1.5mg/day or more, NOMAC effectively suppresses gonadotropic activity and ovulation in women of reproductive age. Hemostasis, lipids and carbohydrate metabolism remain largely unchanged. In normal and cancerous human breast cells, NOMAC has shown favorable effects on estrogen metabolism. Like natural progesterone (but in contrast to some other synthetic progestogens), it does not appear stimulate the proliferation of cancerous breast cells. While there has been some experience of the use of NOMAC in combination with estrogens as a hormone replacement therapy, most of the data on the compound are reported in the context of its inclusion as a component of a new contraceptive pill comprising 2.5mg NOMAC combined with 1.5mg estradiol. Because of its strong endometrial efficacy, and due to its high antigonadotropic activity and long elimination half-life (about 50h), the contraceptive efficacy of the new pill is maintained even when dosages are missed. Furthermore, for the first time with a monophasic 24/4 regimen containing estradiol, cyclical stability can be achieved comparable with that obtained using pills containing ethinyl estradiol and progestogens like levonorgestrel or drospirenone. The addition of NOMAC to estradiol means that the beneficial effects of estrogen are not lost, which is of especial importance in relation to the cardiovascular system. On the basis both of its pharmacology and of studies performed during the development of the NOMAC/estradiol pill, involving some 4000 women in total, good long-term tolerability can be expected for NOMAC, although its safety profile is still to be fully ascertained, as the clinical endpoint studies are yet to be completed. PMID:22364709

  14. Conversion to eslicarbazepine acetate monotherapy

    PubMed Central

    French, Jacqueline; Jacobson, Mercedes P.; Pazdera, Ladislav; Gough, Mallory; Cheng, Hailong; Grinnell, Todd; Blum, David

    2016-01-01

    Objective: To assess the efficacy and safety of eslicarbazepine acetate (ESL) monotherapy. Methods: This post hoc pooled analysis of 2 randomized double-blind studies (093-045 and -046) included adults with partial-onset seizures medically uncontrolled by 1 or 2 antiepileptic drugs (AEDs). Following the baseline period (8 weeks), eligible patients were randomized 2:1 to receive ESL 1,600 mg or 1,200 mg once daily for 18 weeks; the primary endpoint was study exit by meeting predefined exit criteria (signifying worsening seizure control). In each study, treatment was considered effective if the upper 95% confidence limit for exit rate was lower than the historical control threshold (65.3%). Results: Pooled exit rates were as follows: ESL 1,600 mg = 20.6% (95% confidence interval: 15.6%–26.8%); ESL 1,200 mg = 30.8% (23.0%–40.5%). Use of 2 baseline AEDs or rescue medication, US location, epilepsy duration ≥20 years, and higher maximum baseline seizure frequency were associated with higher exit risks. Median percent reductions in standardized seizure frequency between baseline and the 18-week double-blind period were as follows: ESL 1,600 mg = 43.2%; ESL 1,200 mg = 35.7%; baseline carbamazepine use was associated with smaller reductions. Safety profiles were similar between ESL doses. Conclusions: Exit rates for ESL monotherapy (1,600 mg and 1,200 mg once daily) were lower than the historical control threshold, irrespective of baseline AED use and region, with no additional safety concerns identified. Clinical factors and location clearly influence treatment responses in conversion-to-monotherapy trials. Classification of evidence: This pooled analysis provides Class IV evidence that for adults with medically uncontrolled partial-onset seizures, ESL monotherapy is well tolerated and effective. PMID:26911639

  15. [Long-term and short-term effects of propionic/acetic acid ratios on metabolism of glycogen-accumulating organisms].

    PubMed

    Yao, Ying; Chen, Yin-guang; Ma, Min; Gu, Guo-wei

    2007-09-01

    Three activated sludges enriched with glycogen accumulating organisms (GAO) were acclimatized respectively with different ratios of propionic to acetic acid (i.e. biomass SBR-A, C and E) . The effect of different ratios of propionic/acetic acid on the metabolism of long-term cultivated GAO was investigated. Cultivated with high propionic/acetic acid ratio, GAO consumed less glycogen and synthesized less poly-beta-hydroxyalkanoates (PHA) in the anaerobic phase, and in the aerobic phase accumulated less glycogen and degraded less PHA, and at the same time the microbial growth was lower. When the carbon mole of acetic acid equaled that of propionic acid in the influent, GAO utilized acetic acid faster than propionic acid. Batch tests were carried out with biomass SBR-A and SBR-E to study the transient response of long-term cultivated GAO to short-term change of propionic/acetic acid ratio. The GAO cultivated with a high propionic/acetic acid ratio was able to utilize acetic acid immediately when the concentration of acetic acid in the feed suddenly increased. But when the biomass cultivated with a low propionic/acetic acid ratio was feed with high ratio propionic/acetic acid wastewater, the propionic acid uptake rate was only 41.1% of the rate of the GAO long-term cultivated with high propionic/acetic acid. The sudden increase of propionic/acetic acid ratio could effectively inhibit the metabolism of GAO. PMID:17990541

  16. Dietary supplementation with tributyrin alleviates intestinal injury in piglets challenged with intrarectal administration of acetic acid.

    PubMed

    Hou, Yongqing; Wang, Lei; Yi, Dan; Ding, Binying; Chen, Xing; Wang, Qingjing; Zhu, Huiling; Liu, Yulan; Yin, Yulong; Gong, Joshua; Wu, Guoyao

    2014-05-28

    Tributyrin (TBU) is a good dietary source of butyrate and has beneficial effects on the maintenance of normal intestinal morphology. The present study tested the hypothesis that dietary TBU supplementation could alleviate intestinal injury in the acetic acid (ACA)-induced porcine model of colitis. A total of eighteen piglets (25 d old) were randomly allocated to one of three treatment groups (control, ACA and TBU). The control and ACA groups were fed a basal diet and the TBU group was fed the basal diet supplemented with 0·1 % TBU. On day 15 of the trial, under anaesthesia, a soft catheter was inserted into the rectum of piglets (20-25 cm from the anus), followed by administration of either saline (control group) or ACA (10 ml of 10 % ACA solution for ACA and TBU groups). On day 22 of the trial, after venous blood samples were collected, piglets were killed to obtain mid-ileum and mid-colon mucosae. Compared with the control group, the ACA group exhibited an increase (P< 0·05) in lymphocyte counts, creatinine, PGE2, and malondialdehyde concentrations and diamine oxidase and inducible NO synthase activities in the plasma and lymphocyte density in the colon and a decrease in insulin concentrations and glutathione peroxidase activity, ileal villus height:crypt depth ratios and goblet cell numbers in the colon. These adverse effects of ACA were attenuated by TBU supplementation. Moreover, TBU prevented the ACA-induced increase in caspase-3 levels while enhancing claudin-1 protein and epidermal growth factor receptor (EGFR) mRNA expression in the colonic mucosa. Collectively, these results indicate that dietary supplementation with 0·1 % TBU alleviates ACA-induced intestinal injury possibly by inhibiting apoptosis, promoting tight-junction formation and activating EGFR signalling. PMID:24506942

  17. Rapid remodeling of tight junctions during paracellular diapedesis in a human model of the blood-brain barrier.

    PubMed

    Winger, Ryan C; Koblinski, Jennifer E; Kanda, Takashi; Ransohoff, Richard M; Muller, William A

    2014-09-01

    Leukocyte transendothelial migration (TEM; diapedesis) is a critical event in immune surveillance and inflammation. Most TEM occurs at endothelial cell borders (paracellular). However, there is indirect evidence to suggest that, at the tight junctions of the blood-brain barrier (BBB), leukocytes migrate directly through the endothelial cell body (transcellular). Why leukocytes migrate through the endothelial cell body rather than the cell borders is unknown. To test the hypothesis that the tightness of endothelial cell junctions influences the pathway of diapedesis, we developed an in vitro model of the BBB that possessed 10-fold higher electrical resistance than standard culture conditions and strongly expressed the BBB tight junction proteins claudin-5 and claudin-3. We found that paracellular TEM was still the predominant pathway (≥98%) and TEM was dependent on PECAM-1 and CD99. We show that endothelial tight junctions expressing claudin-5 are dynamic and undergo rapid remodeling during TEM. Membrane from the endothelial lateral border recycling compartment is mobilized to the exact site of tight junction remodeling. This preserves the endothelial barrier by sealing the intercellular gaps with membrane and engaging the migrating leukocyte with unligated adhesion molecules (PECAM-1 and CD99) as it crosses the cell border. These findings provide new insights into leukocyte-endothelial interactions at the BBB and suggest that tight junctions are more dynamic than previously appreciated. PMID:25063869

  18. Acute alcohol intoxication decreases glucose metabolism but increases acetate uptake in the human brain.

    PubMed

    Volkow, Nora D; Kim, Sung Won; Wang, Gene-Jack; Alexoff, David; Logan, Jean; Muench, Lisa; Shea, Colleen; Telang, Frank; Fowler, Joanna S; Wong, Christopher; Benveniste, Helene; Tomasi, Dardo

    2013-01-01

    Alcohol intoxication results in marked reductions in brain glucose metabolism, which we hypothesized reflect not just its GABAergic enhancing effects but also the metabolism of acetate as an alternative brain energy source. To test this hypothesis we separately assessed the effects of alcohol intoxication on brain glucose and acetate metabolism using Positron Emission Tomography (PET). We found that alcohol intoxication significantly decreased whole brain glucose metabolism (measured with FDG) with the largest decrements in cerebellum and occipital cortex and the smallest in the thalamus. In contrast, alcohol intoxication caused a significant increase in [1-(11)C]acetate brain uptake (measured as standard uptake value, SUV), with the largest increases occurring in the cerebellum and the smallest in the thalamus. In heavy alcohol drinkers [1-(11)C]acetate brain uptake during alcohol challenge tended to be higher than in occasional drinkers (p<0.06) and the increases in [1-(11)C]acetate uptake in cerebellum with alcohol were positively associated with the reported amount of alcohol consumed (r=0.66, p<0.01). Our findings corroborate a reduction of brain glucose metabolism during intoxication and document an increase in brain acetate uptake. The opposite changes observed between regional brain metabolic decrements and regional increases in [1-(11)C]acetate uptake support the hypothesis that during alcohol intoxication the brain may rely on acetate as an alternative brain energy source and provides preliminary evidence that heavy alcohol exposures may facilitate the use of acetate as an energy substrate. These findings raise the question of the potential therapeutic benefits that increasing plasma acetate concentration (i.e. ketogenic diets) may have in alcoholics undergoing alcohol detoxification. PMID:22947541

  19. Naturally fractured tight gas reservoirs detection optimization

    SciTech Connect

    Hoekstra, P.

    1995-04-01

    This contract is a joint project between METC and Louisiana Land and Exploration, planned to extend for 3 years. Substantial help and key information has been provided at the field by the owner/operator. All their well logs, cores, production data, geologic data, and geophysical data are available for study in this project. Their commitment in this technology development is demonstrated by their proposed contribution in the form of cost sharing: (1) obtaining the P-Wave (compressional wave) 3-D survey, (2) furnishing a borehole in which to acquire the 9-C vertical seismic profile (VSP), and (3) drilling and completing a test well for verification of the seismic anomaly. Also of significance is the direct involvement and participation of their professional staff. This staff has been responsible for generating and maintaining the database at the field and will form part of the team which evaluates the seismic data`s findings.

  20. Development of xylose-fermenting yeasts for ethanol production at high acetic acid concentrations

    SciTech Connect

    Mohandas, D.V.; Whelan, D.R.; Panchal, C.J.

    1995-12-31

    Mutants resistant to comparatively high levels of acetic acid were isolated from the xylose-fermenting yeasts Candida shehatae and Pichia Stipitis by adapting these cultures to increasing concentrations of acetic acid grown in shake-flask cultures. These mutants were tested for their ability to ferment xylose in presence of high acetic acid concentrations, in acid hydrolysates of wood, and in hardwood spent sulfite liquor, and compared with their wild-type counterparts and between themselves. The P. stipitis mutant exhibited faster fermentation times, better tolerance to acid hydrolysates, and tolerance to lower pH.

  1. Clostridium thermosaccharolyticum strain deficient in acetate production

    SciTech Connect

    Rothstein, D.M.

    1986-01-01

    A mutant of Clostridium thermosaccharolyticum that is blocked in acetate production was isolated after treatment with nitrosoguanidine and selection for fluoroacetate resistance. The mutant produced more ethanol than the parent strain did.

  2. Acetate Causes Alcohol Hangover Headache in Rats

    PubMed Central

    Maxwell, Christina R.; Spangenberg, Rebecca Jay; Hoek, Jan B.; Silberstein, Stephen D.; Oshinsky, Michael L.

    2010-01-01

    Background The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache. Methods We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats. Results Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia), followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate increased nociceptive behaviors suggesting that acetate, not acetaldehyde, accumulation results in hangover-like hypersensitivity in our model. Since adenosine accumulation is a result of acetate formation, we administered an adenosine antagonist that blocked hypersensitivity. Discussion Our study shows that acetate contributes to hangover headache. These findings provide insight into the mechanism of hangover headache and the mechanism of headache induction. PMID:21209842

  3. Mafenide acetate allergy presenting as recurrent chondritis.

    PubMed

    Pickus, Evan J; Lionelli, Gerald T; Charles, E Woodall; Korentager, Richard A

    2002-02-01

    Acute chondritis has a strong predilection for recurrence. Mafenide acetate has been implicated in causing reactions that mimic this condition; however, these hypersensitivity reactions lack fever, fluctuance, and pain. The authors report a case of mafenide acetate allergy presenting as recurrent chondritis in a patient who had previously been treated successfully for this condition. In this patient, the allergic response resolved within 3 days after cessation of mafenide acetate. If unappreciated, it may have led to unnecessary operative intervention. Therefore, auricular edema and erythema, without fever, fluctuance, and pain, must be recognized by surgeons as a possible mafenide acetate allergy and must be considered in the differential diagnosis for patients who present with recurrent acute suppurative chondritis. PMID:11910229

  4. Nomegestrol acetate/estradiol: in oral contraception.

    PubMed

    Yang, Lily P H; Plosker, Greg L

    2012-10-01

    Nomegestrol acetate/estradiol is a combined oral contraceptive with approval in many countries. This fixed-dose combination tablet contains nomegestrol acetate, a highly selective progestogen, and estradiol, a natural estrogen. It is the first monophasic combined oral contraceptive to contain estradiol, and is taken in 28-day cycles, consisting of 24 active therapy days with 4 placebo days (i.e. 24/4-day cycles). In two large, 1-year, randomized, open-label, multicentre, phase III trials in healthy adult women (aged 18-50 years), nomegestrol acetate/estradiol was at least as effective as drospirenone/ethinylestradiol as contraceptive therapy, as the pregnancy rates in women aged 18-35 years (primary efficacy population) in terms of the Pearl Index (primary endpoint) were numerically lower with nomegestrol acetate/estradiol, although the between-group difference was not statistically significant. In both trials, nomegestrol acetate/estradiol was given in a 24/4-day cycle, and drospirenone/ethinylestradiol was given in a 21/7-day cycle. The criteria for using condoms in case of forgotten doses were less stringent in the nomegestrol acetate/estradiol group than in the drospirenone/ethinylestradiol group. Nomegestrol acetate/estradiol therapy for up to 1 year was generally well tolerated in healthy adult women, with an acceptable tolerability profile in line with that expected for a combined oral contraceptive. The most commonly reported adverse events were acne and abnormal withdrawal bleeding (most often shorter, lighter or absent periods). Overall, compared with drospirenone/ethinylestradiol, nomegestrol acetate/estradiol appeared to be associated with less favourable acne-related outcomes, and shorter, lighter or absent periods. PMID:22950535

  5. Methanogenesis from acetate: a nonmethanogenic bacterium from an anaerobic acetate enrichment.

    PubMed

    Ward, D M; Mah, R A; Kaplan, I R

    1978-06-01

    A methanogenic acetate enrichment was initiated by inoculation of an acetate-mineral salts medium with domestic anaerobic digestor sludge and maintained by weekly transfer for 2 years. The enrichment culture contained a Methanosarcina and several obligately anaerobic nonmethanogenic bacteria. These latter organisms formed varying degrees of association with the Methanosarcina, ranging from the nutritionally fastidious gram-negative rod called the satellite bacterium to the nutritionally nonfastidious Eubacterium limosum. The satellite bacterium had growth requirements for amino acids, a peptide, a purine base, vitamin B12, and other B vitamins. Glucose, mannitol, starch, pyruvate, cysteine, lysine, leucine, isoleucine, arginine, and asparagine stimulated growth and hydrogen production. Acetate was neither incorporated nor metabolized by the satellite organism. Since acetate was the sole organic carbon source in the enrichment culture, organism(s) which metabolize acetate (such as the Methanosarcina) must produce substrates and growth factors for associated organisms which do not metabolize acetate. PMID:677881

  6. Tight gas sands study breaks down drilling and completion costs

    SciTech Connect

    Brunsman, B. ); Saunders, B. )

    1994-06-06

    Given the high cost to drill and complete tight gas sand wells, advances in drilling and completion technology that result in even modest cost savings to the producer have the potential to generate tremendous savings for the natural gas industry. The Gas Research Institute sponsored a study to evaluate drilling and completion costs in selected tight gas sands. The objective of the study was to identify major expenditures associated with tight gas sand development and determine their relative significance. A substantial sample of well cost data was collected for the study. Individual well cost data were collected from nearly 300 wells in three major tight gas sand formations: the Cotton Valley sand in East Texas, the Frontier sand in Wyoming, and the Wilcox sand in South Texas. The data were collected and organized by cost category for each formation. After the information was input into a data base, a simple statistical analysis was performed. The statistical analysis identified data discrepancies that were then resolved, and it helped allow conclusions to be drawn regarding drilling and completion costs in these tight sand formations. Results are presented.

  7. Altering wettability to recover more oil from tight formations

    DOE PAGESBeta

    Brady, Patrick V.; Bryan, Charles R.; Thyne, Geoffrey; Li, Huina

    2016-06-03

    We describe here a method for chemically modifying fracturing fluids and overflushes to chemically increase oil recovery from tight formations. Oil wetting of tight formations is usually controlled by adhesion to illite, kerogen, or both; adhesion to carbonate minerals may also play a role. Oil-illite adhesion is sensitive to salinity, dissolved divalent cation content, and pH. We measure oil-rock adhesion with middle Bakken formation oil and core to verify a surface complexation model of reservoir wettability. The agreement between the model and experiments suggests that wettability trends in tight formations can be quantitatively predicted and that fracturing fluid and overflushmore » compositions can be individually tailored to increase oil recovery.« less

  8. Claudin heterogeneity and control of lung tight junctions.

    PubMed

    Koval, Michael

    2013-01-01

    Lung epithelial cells interconnected by tight junctions provide a barrier to the free diffusion of solutes into airspaces. Transmembrane tight junction proteins known as claudins are essential for epithelial barrier function. Claudins are regulated through interactions with each other that are coordinated with other transmembrane tight junction proteins and cytosolic scaffold proteins. Of the 14 claudins expressed by the alveolar epithelium, claudin-3, claudin-4, and claudin-18 are the most prominent; each confers unique properties to alveolar barrier function. In particular, a protective role for claudin-4 in preventing lung injury has emerged. By contrast, lung diseases that affect claudin expression and impair barrier function, including alcoholic lung syndrome and sepsis, prime the lung for pulmonary edema. Thus, approaches to restore and/or augment lung claudin expression provide potential targets for promoting healthy barrier function. PMID:23072447

  9. Undersampled MR Image Reconstruction with Data-Driven Tight Frame

    PubMed Central

    Liu, Jianbo; Wang, Shanshan; Peng, Xi; Liang, Dong

    2015-01-01

    Undersampled magnetic resonance image reconstruction employing sparsity regularization has fascinated many researchers in recent years under the support of compressed sensing theory. Nevertheless, most existing sparsity-regularized reconstruction methods either lack adaptability to capture the structure information or suffer from high computational load. With the aim of further improving image reconstruction accuracy without introducing too much computation, this paper proposes a data-driven tight frame magnetic image reconstruction (DDTF-MRI) method. By taking advantage of the efficiency and effectiveness of data-driven tight frame, DDTF-MRI trains an adaptive tight frame to sparsify the to-be-reconstructed MR image. Furthermore, a two-level Bregman iteration algorithm has been developed to solve the proposed model. The proposed method has been compared to two state-of-the-art methods on four datasets and encouraging performances have been achieved by DDTF-MRI. PMID:26199641

  10. Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.

    SciTech Connect

    Snyder, S. W.; Energy Systems

    2010-02-08

    Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4

  11. Definitive evidence for the existence of tight junctions in invertebrates.

    PubMed

    Lane, N J; Chandler, H J

    1980-09-01

    Extensive and unequivocal tight junctions are here reported between the lateral borders of the cellular layer that circumscribes the arachnid (spider) central nervous system. This account details the features of these structures, which form a beltlike reticulum that is more complex than the simple linear tight junctions hitherto found in invertebrate tissues and which bear many of the characteristics of vertebrate zonulae occludentes. We also provide evidence that these junctions form the basis of a permeability barrier to exogenous compounds. In thin sections, the tight junctions are identifiable as punctate points of membrane apposition; they are seen to exclude the stain and appear as election- lucent moniliform strands along the lines of membrane fusion in en face views of uranyl-calcium-treated tissues. In freeze-fracture replicas, the regions of close membrane apposition exhibit P-face (PF) ridges and complementary E-face (EF) furrows that are coincident across face transitions, although slightly offset with respect to one another. The free inward diffusion of both ionic and colloidal lanthanum is inhibited by these punctate tight junctions so that they appear to form the basis of a circumferential blood-brain barrier. These results support the contention that tight junctions exist in the tissues of the invertebrata in spite of earlier suggestions that (a) they are unique to vertebrates and (b) septate junctions are the equivalent invertebrate occluding structure. The component tight junctional 8- to 10-nm-particulate PF ridges are intimately intercalated with, but clearly distinct from, inverted gap junctions possessing the 13-nm EF particles typical of arthropods. Hence, no confusion can occur as to which particles belong to each of the two junctional types, as commonly happens with vertebrate tissues, especially in the analysis of developing junctions. Indeed, their coexistance in this way supports the idea, over which there has been some controversy, that

  12. Stratification of Hepatocellular Carcinoma Patients Based on Acetate Utilization.

    PubMed

    Björnson, Elias; Mukhopadhyay, Bani; Asplund, Anna; Pristovsek, Nusa; Cinar, Resat; Romeo, Stefano; Uhlen, Mathias; Kunos, George; Nielsen, Jens; Mardinoglu, Adil

    2015-12-01

    Hepatocellular carcinoma (HCC) is a deadly form of liver cancer that is increasingly prevalent. We analyzed global gene expression profiling of 361 HCC tumors and 49 adjacent noncancerous liver samples by means of combinatorial network-based analysis. We investigated the correlation between transcriptome and proteome of HCC and reconstructed a functional genome-scale metabolic model (GEM) for HCC. We identified fundamental metabolic processes required for cell proliferation using the network centric view provided by the GEM. Our analysis revealed tight regulation of fatty acid biosynthesis (FAB) and highly significant deregulation of fatty acid oxidation in HCC. We predicted mitochondrial acetate as an emerging substrate for FAB through upregulation of mitochondrial acetyl-CoA synthetase (ACSS1) in HCC. We analyzed heterogeneous expression of ACSS1 and ACSS2 between HCC patients stratified by high and low ACSS1 and ACSS2 expression and revealed that ACSS1 is associated with tumor growth and malignancy under hypoxic conditions in human HCC. PMID:26655911

  13. Fluid identification in tight sandstone reservoirs based on a new rock physics model

    NASA Astrophysics Data System (ADS)

    Sun, Jianmeng; Wei, Xiaohan; Chen, Xuelian

    2016-08-01

    To identify pore fluids, we establish a new rock physics model named the tight sandstone dual-porosity model based on the Voigt–Reuss–Hill model, approximation for the Xu–White model and Gassmann’s equation to predict elastic wave velocities. The modeling test shows that predicted sonic velocities derived from this rock physics model match well with measured ones from logging data. In this context, elastic moduli can be derived from the model. By numerical study and characteristic analyzation of different elastic properties, a qualitative fluid identification method based on Poisson’s ratio and the S–L dual-factor method based on synthetic moduli is proposed. Case studies of these two new methods show the applicability in distinguishing among different fluids and different layers in tight sandstone reservoirs.

  14. Brain barriers: Crosstalk between complex tight junctions and adherens junctions

    PubMed Central

    Tietz, Silvia

    2015-01-01

    Unique intercellular junctional complexes between the central nervous system (CNS) microvascular endothelial cells and the choroid plexus epithelial cells form the endothelial blood–brain barrier (BBB) and the epithelial blood–cerebrospinal fluid barrier (BCSFB), respectively. These barriers inhibit paracellular diffusion, thereby protecting the CNS from fluctuations in the blood. Studies of brain barrier integrity during development, normal physiology, and disease have focused on BBB and BCSFB tight junctions but not the corresponding endothelial and epithelial adherens junctions. The crosstalk between adherens junctions and tight junctions in maintaining barrier integrity is an understudied area that may represent a promising target for influencing brain barrier function. PMID:26008742

  15. Invisibility in non-Hermitian tight-binding lattices

    SciTech Connect

    Longhi, Stefano

    2010-09-15

    Reflectionless defects in Hermitian tight-binding lattices, synthesized by the intertwining operator technique of supersymmetric quantum mechanics, are generally not invisible and time-of-flight measurements could reveal the existence of the defects. Here it is shown that, in a certain class of non-Hermitian tight-binding lattices with complex hopping amplitudes, defects in the lattice can appear fully invisible to an outside observer. The synthesized non-Hermitian lattices with invisible defects possess a real-valued energy spectrum; however, they lack parity-time (PT) symmetry, which does not play any role in the present work.

  16. Tight coupling expansion and fully inhomogeneous magnetic fields

    SciTech Connect

    Giovannini, Massimo

    2006-09-15

    The tight coupling expansion, appropriately generalized to include large-scale magnetic fields, allows the estimate of the brightness perturbations of CMB anisotropies for typical wavelengths that are larger than the Hubble radius after matter-radiation equality. After discussing the basic features of the predecoupling initial conditions in the presence of fully inhomogeneous magnetic fields, the tight coupling expansion is studied both analytically and numerically. From the requirement that the amplitudes and phases of Sakharov oscillations are (predominantly) adiabatic and from the inferred value of the plateau in the temperature autocorrelation, the effects of the magnetized contribution can be systematically investigated and constrained.

  17. Acceleration of electrons by a tightly focused intense laser beam.

    PubMed

    Li, Jian-Xing; Zang, Wei-Ping; Li, Ya-Dong; Tian, Jian-Guo

    2009-07-01

    The recent proposal to use Weinger transformation field (WTF) [Opt. Express 17, 4959-4969 (2009)] for describing tightly focused laser beams is investigated here in detail. In order to validate the accuracy of WTF, we derive the numerical field (NF) from the plane wave spectrum method. WTF is compared with NF and Lax series field (LSF). Results show that LSF is accurate close to the beam axis and divergent far from the beam axis, and WTF is always accurate. Moreover, electron dynamics in a tightly focused intense laser beam are simulated by LSF, WTF and NF, respectively. The results obtained by WTF are shown to be accurate. PMID:19582099

  18. Band structure of silicene in the tight binding approximation

    SciTech Connect

    Gert, A. V. Nestoklon, M. O.; Yassievich, I. N.

    2015-07-15

    The electronic structure of silicene is simulated by the tight binding method with the basis sp{sup 3}d{sup 5}s*. The results are in good agreement with ab initio calculations. The effective Hamiltonian of silicene in the vicinity of the Dirac point is constructed by the method of invariants. Silicon atoms in silicene are located in two parallel planes displaced perpendicularly to each other by Δ{sub z}; the energy spectrum essentially depends on this displacement. Using the tight binding technique, the coefficients of the effective Hamiltonian are determined for various values of Δ{sub z}.

  19. Adrenocortical suppression in cats given megestrol acetate.

    PubMed

    Chastain, C B; Graham, C L; Nichols, C E

    1981-12-01

    Megestrol acetate was given orally to 8 cats at a dose of 2.5 mg every other day for 2 weeks and to 8 cats at a dose of 5.0 mg every day for 2 weeks. Four cats were designated nontreated controls. Pre-ACTH-stimulated plasma concentrations of cortisol (hydrocortisone) and ACTH-stimulated cortisol and tolerance to large-dose glucose infusion (IV) were determined on each of the 20 cats given megestrol acetate. Cats were restrained with acepromazine maleate and ketamine hydrochloride during blood sample collection and large-dose glucose infusion. Adrenocortical function and tolerance to large-dose glucose infusion were reevaluated for 4 weeks--after 1st and 2nd weeks of megestrol acetate treatment of the treated groups, and after 1st and 2nd weeks when treatment was stopped (ie, experiment weeks 3 and 4). Each week a cat from the control group and 2 cats from the 2 treated groups were selected to determine the changes occurring during the experiment for that week; after collection of plasma samples, each week's 5 selected cats were euthanatized and necropsied. Significant impairment of adrenocortical function and alteration of adrenocortical morphology occurred with both treated groups. The most severe adrenocortical alterations occurred in the cats 1 week after megestrol acetate was no longer given (ie, experiment week 3). Megestrol acetate-induced adrenocortical suppression contributed to the death of 1 cat. It was concluded that if stress occurs to cats on treatment or soon after treatment with megestrol acetate, glucocorticoids should be supplemented. The effects of megestrol acetate on glucose tolerance were overshadowed by the unforeseen intolerance caused by chemical restraint with acepromazine maleate and ketamine hydrochloride. PMID:6280517

  20. The antimicrobial effect of acetic acid--an alternative to common local antiseptics?

    PubMed

    Ryssel, H; Kloeters, O; Germann, G; Schäfer, Th; Wiedemann, G; Oehlbauer, M

    2009-08-01

    Acetic acid has been commonly used in medicine for more than 6000 years for the disinfection of wounds and especially as an antiseptic agent in the treatment and prophylaxis of the plague. The main goal of this study was to prove the suitability of acetic acid, in low concentration of 3%, as a local antiseptic agent, especially for use in salvage procedures in problematic infections caused by organisms such as Proteus vulgaris, Acinetobacter baumannii or Pseudomonas aeruginosa. This study was designed to compare the in vitro antimicrobial effect of acetic acid with those of common local antiseptics such as povidone-iodine 11% (Betaisodona), polyhexanide 0.04% (Lavasept), mafenide 5% and chlohexidine gluconate 1.5% cetrimide 15% (Hibicet). Former studies suggest the bactericidal effect of acetic acid, but these data are very heterogeneous; therefore, a standardised in vitro study was conducted. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacterial strains were tested: Escherichia coli, P. vulgaris, P. aeruginosa, A. baumannii, Enterococcus faecalis, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A and B. The tests showed excellent bactericidal effect of acetic acid, particularly with problematic Gram-negative bacteria such as P. vulgaris, P. aeruginosa and A. baumannii. The microbiological spectrum of acetic acid is wide, even when tested at a low concentration of 3%. In comparison to our currently used antiseptic solutions, it showed similar - in some bacteria, even better - bactericidal properties. An evaluation of the clinical value of topical application of acetic acid is currently underway. It can be concluded that acetic acid in a concentration of 3% has excellent bactericidal effect and, therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary. PMID:19286325

  1. Acetate Transport and Utilization in the Rat Brain

    PubMed Central

    Deelchand, Dinesh K.; Shestov, Alexander A.; Koski, Dee M.; Uğurbil, Kâmil; Henry, Pierre-Gilles

    2009-01-01

    Acetate, a glial-specific substrate, is an attractive alternative to glucose for the study of neuronal-glial interactions. The present study investigates the kinetics of acetate uptake and utilization in the rat brain in vivo during infusion of [2-13C]acetate using NMR spectroscopy. When plasma acetate concentration was increased, the rate of brain acetate utilization (CMRace) increased progressively and reached close to saturation for plasma acetate concentration > 2-3 mM, whereas brain acetate concentration continued to increase. The Michaelis-Menten constant for brain acetate utilization ( KMutil=0.01±0.14mM) was much smaller than for acetate transport through the blood-brain barrier ( KMt=4.18±0.83mM). The maximum transport capacity of acetate through the blood-brain barrier ( Vmaxt=0.96±0.18μmol/g/min) was nearly two-fold higher than the maximum rate of brain acetate utilization ( Vmaxutil=0.50±0.08μmol/g/min). We conclude that, under our experimental conditions, brain acetate utilization is saturated when plasma acetate concentrations increase above 2-3 mM. At such high plasma acetate concentration, the rate-limiting step for glial acetate metabolism is not the blood-brain barrier, but occurs after entry of acetate into the brain. PMID:19393008

  2. Intraoperative Tight Glucose Control Using Hyperinsulinemic Normoglycemia Increases Delirium After Cardiac Surgery

    PubMed Central

    Saager, Leif; Duncan, Andra E.; Yared, Jean-Pierre; Hesler, Brian D.; You, Jing; Deogaonkar, Anupa; Sessler, Daniel I.; Kurz, Andrea

    2015-01-01

    Background Postoperative delirium is common in patients recovering from cardiac surgery. Tight glucose control has been shown to reduce mortality and morbidity. We therefore sought to determine the effect of tight intraoperative glucose control using a hyper-insulinemic normoglycemic clamp approach on postoperative delirium in patients undergoing cardiac surgery. Methods We enrolled 198 adult patients having cardiac surgery in this randomized, double-blinded single-center trial. Patients were randomly assigned to either tight intraoperative glucose control with a hyperinsulinemic-normoglycemic clamp (target blood glucose: 80–110 mg/dL) or standard therapy (conventional insulin administration with blood glucose target < 150 mg/dL). Delirium was assessed using a comprehensive delirium battery. We considered patients to have experienced postoperative delirium when Confusion Assessment Method testing was positive at any assessment. A positive Confusion Assessment Method test was defined by the presence of features 1 (acute onset and fluctuating course) and 2 (inattention), and either 3 (disorganized thinking) or 4 (altered consciousness). Results Patients randomized to tight glucose control were more likely to be diagnosed as being delirious than those assigned to routine glucose control (26/93 vs. 15/105; Relative Risk (RR), 95% CI: 1.89, 1.06–3.37; P = 0.03), after adjusting for preoperative usage of calcium channel blocker and American Society of Anesthesiologist (ASA) physical status. Delirium severity, among patients with delirium, was comparable with each glucose management strategy. Conclusions Intraoperative hyperinsulinemic-normoglycemia augments the risk of delirium after cardiac surgery, but not its severity. PMID:25992877

  3. Ethylene-Vinyl Acetate Potential Problems for Photovoltaic Packaging

    SciTech Connect

    Kempe, M. D.; Jorgensen, G. J.; Terwilliger, K. M.; McMahon, T. J.; Kennedy, C. E.; Borek, T. T.

    2006-01-01

    Photovoltaic (PV) devices are typically encapsulated using ethylene-vinyl acetate (EVA) to provide mechanical support, optical coupling, electrical isolation, and protection against environmental exposure. Under exposure to atmospheric water and/or ultraviolet radiation, EVA will decompose to produce acetic acid, lowering the pH and increasing the surface corrosion rates of embedded devices. Even though acetic acid is produced at a very slow rate, it may not take much to catalyze reactions that lead to rapid module deterioration. Another consideration is that the glass transition of EVA, as measured using dynamic mechanical analysis, begins at temperatures of about -15 degC. Temperatures lower than this can be reached for extended periods of time in some climates. Because of increased moduli below the glass transition temperature, a module may be more vulnerable to damage if a mechanical load is applied by snow or wind at low temperatures. Modules using EVA should not be rated for use at such low temperatures without additional low-temperature mechanical testing beyond the scope of UL1703.

  4. Induction of the acetamidase of Aspergillus nidulans by acetate metabolism.

    PubMed

    Hynes, M J

    1977-09-01

    Growth tests and enzyme determinations strongly suggest that the acetamidase of Aspergillus nidulans is induced by a product of acetate metabolism rather than the substrate, acetamide. The cis-dominant mutation, amdI9, which is closely linked to amdS, the structural gene for the acetamidase, results in greatly increased sensitivity to induction by acetate metabolism. Propionate, L-threonine, and ethanol also result in acetamidase induction. Mutations in the facA, facB, and facC genes, which lead to low levels of acetyl-coenzyme A synthase, are epistatic to the amdI9 mutation for strong growth on acetamide medium and abolish acetamide and propionamide induction of the acetamidase and isocitrate lyase enzymes. Acetate, L-threonine, and ethanol, however, can induce these enzymes in strains containing facA and facC lesions but not in strains containing a facB lesion. The evidence suggests that acetamidase and isocitrate lyase may be induced by a similar mechanism. PMID:19418

  5. Ethylene-Vinyl Acetate Potential Problems for Photovoltaic Packaging: Preprint

    SciTech Connect

    Kempe, M. D.; Jorgensen, G. J.; Terwilliger, K. M.; McMahon, T. J.; Kennedy, C. E.; Borek, T. T.

    2006-05-01

    Photovoltaic (PV) devices are typically encapsulated using ethylene-vinyl acetate (EVA) to provide mechanical support, optical coupling, electrical isolation, and protection against environmental exposure. Under exposure to atmospheric water and/or ultraviolet radiation, EVA will decompose to produce acetic acid, lowering the pH and increasing the surface corrosion rates of embedded devices. Even though acetic acid is produced at a very slow rate, it may not take much to catalyze reactions that lead to rapid module deterioration. Another consideration is that the glass transition of EVA, as measured using dynamic mechanical analysis, begins at temperatures of about ?15 C. Temperatures lower than this can be reached for extended periods of time in some climates. Because of increased moduli below the glass transition temperature, a module may be more vulnerable to damage if a mechanical load is applied by snow or wind at low temperatures. Modules using EVA should not be rated for use at such low temperatures without additional low-temperature mechanical testing beyond the scope of UL 1703.

  6. Acetylation of Starch with Vinyl Acetate in Imidazolium Ionic Liquids and Characterization of Acetate Distribution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch was acetylated with vinyl acetate in different 1-butyl-3-methylimidazolium (BMIM) salts as solvent in effort to produce starches with different acetylation patterns. Overall degree of substitution was much higher for basic anions such as acetate and dicyanimide (dca) than for neutral anions ...

  7. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... new uses subject to reporting. (1) The chemical substances identified as 2-ethoxyethanol (CAS No. 110-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and 2-methoxyethanol acetate (CAS No. 110-49-6) are subject to reporting under this section for the significant new...

  8. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... new uses subject to reporting. (1) The chemical substances identified as 2-ethoxyethanol (CAS No. 110-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and 2-methoxyethanol acetate (CAS No. 110-49-6) are subject to reporting under this section for the significant new...

  9. [Degradation of thiometon in ethyl acetate].

    PubMed

    Satoh, M; Shimokawa, S; Kobata, M; Tanaka, T; Nakanishi, Y

    2001-04-01

    When performing multiresidue analysis of pesticides, the recovery of thiometon was less than 20% from carrots and eggplants, but about 100% from garlic chives and welsh onions. The recovery of thiometon was found to depend on the lot of ethyl acetate. A 2-year-old lot of ethyl acetate caused degradation of thiometon, but a fresh lot of ethyl acetate did not. Analysis showed that ethyl acetate stored for 2 years contained about 5 microL/mL of acetaldehyde. Thiometon was also degraded by acetone or acetonitrile, when acetaldehyde was added to them, in the same manner as by aged ethyl acetate. The fact that the recovery of thiometon from welsh onions was about 100% indicated that some of the mercaptans in allium vegetables may prevent thiometon degradation. Mercaptans such as L-cysteine and 3-mercaptoproionic acid were confirmed to prevent the degradation of thiometon and disulfoton. These findings show that mercaptans may be useful additives for analyzing thiometon and disulfoton. PMID:11486375

  10. Use of fibre wastes from production of acetate fibres

    SciTech Connect

    Askarov, M.I.; Tashpulatova, A.B.

    1995-07-01

    The rational use of production wastes is an important part of the Fergana Chemical Fibre Plant in Russia. This recycling reduces the negative effect of the technological process on the environment, increases the economy of production, and produces additional consumer goods. Consumer goods began to be produced at the plant in 1978 with processing of amide-acetate textured fibres into yarn for hand knitting. The need to increase the volumes and expand the variety of goods for the market predetermined an important increase in production of this product. Production of consumer goods has increased since 1990, and both fibre wastes and untreated low-grade fibres and filaments have been used as the starting material. Technological processes for processing wastes and low-grade figured, textured polyamide-acetate fibres into knitting yarn, haberdashery cord, and finishing tape and fringe were created and introduced in subsequent years. The primary technological formulation for production of these materials is well known and is used in light industry. However, production of each type of product in the plant was preceded by research related to selection of the optimum linear density of the filaments used, composition of blends, and the structure of figured fibres, as well as the concrete technological parameters and operating regimes of the equipment to produce articles of the required quality. Development and testing of new decorative textiles are continuing. Low grade and nonstandard acetate semifinished fibre from spinning machines and low grade, bulk dyed acetate fibres have been selected as the raw material for fabrication of these articles.

  11. Dual signaling of hydrazine by selective deprotection of dichlorofluorescein and resorufin acetates.

    PubMed

    Choi, Myung Gil; Moon, Jung Ok; Bae, Jihee; Lee, Jung Woo; Chang, Suk-Kyu

    2013-05-14

    The highly selective chemosignaling behaviors for hydrazine by a reaction-based probe of dichlorofluorescein and resorufin acetates were investigated. Hydrazinolysis of latent dichlorofluorescein and resorufin acetate fluorochromes caused prominent chromogenic and fluorescent turn-on type signals. The probes selectively detected hydrazine in the presence of commonly encountered metal ions and anions as background. Dichlorofluorescein and resorufin acetates selectively detected hydrazine with detection limits of 9.0 × 10(-8) M and 8.2 × 10(-7) M, respectively. Furthermore, hydrazine was selectively detected over other closely related compounds, such as hydroxylamine, ethylenediamine, and ammonia. As a possible application of the acetate probes, hydrazine signaling in tap water was tested. PMID:23487180

  12. Tightness of stability bounds by null space property

    NASA Astrophysics Data System (ADS)

    Chen, Xuemei; Wang, Rongrong

    2015-08-01

    The null space property (NSP) and the restricted isometry property (RIP) are two properties which have received considerable attention in the compressed sensing literature. It is known that the null space property guarantees a less than ideal stability result. In this paper, we show that this bound is actually tight by specific construction, which implies a fundamental difference between NSP and RIP.

  13. 18 CFR 270.304 - Tight formation gas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Tight formation gas. 270.304 Section 270.304 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY PROCEDURES GOVERNING DETERMINATIONS FOR TAX CREDIT PURPOSES DETERMINATION PROCEDURES Requirements for Filings...

  14. 18 CFR 270.304 - Tight formation gas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Tight formation gas. 270.304 Section 270.304 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY PROCEDURES GOVERNING DETERMINATIONS FOR TAX CREDIT PURPOSES DETERMINATION PROCEDURES Requirements for Filings...

  15. 18 CFR 270.305 - Determination of tight formation areas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Determination of tight formation areas. 270.305 Section 270.305 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY PROCEDURES GOVERNING DETERMINATIONS FOR TAX CREDIT PURPOSES DETERMINATION PROCEDURES Requirements...

  16. Tight Junction Pore and Leak Pathways: A Dynamic Duo

    PubMed Central

    Raleigh, David R.; Yu, Dan; Turner, Jerrold R.

    2015-01-01

    Tissue barriers that restrict passage of liquids, ions, and larger solutes are essential for the development of multicellular organisms. In simple organisms this allows distinct cell types to interface with the external environment. In more complex species, the diversity of cell types capable of forming barriers increases dramatically. Although the plasma membranes of these barrier-forming cells prevent flux of most hydrophilic solutes, the paracellular, or shunt, pathway between cells must also be sealed. This function is accomplished in vertebrates by the zonula occludens, or tight junction. The tight junction barrier is not absolute but is selectively permeable and is able to discriminate between solutes on the basis of size and charge. Many tight junction components have been identified over the past 20 years, and recent progress has provided new insights into the proteins and interactions that regulate structure and function. This review presents these data in a historical context and proposes an integrated model in which dynamic regulation of tight junction protein interactions determines barrier function. PMID:20936941

  17. Estrogen Modulates Expression of Tight Junction Proteins in Rat Vagina

    PubMed Central

    Oh, Kyung-Jin; Ahn, Kyuyoun

    2016-01-01

    Background. The objectives of this study were to investigate the localization of tight junctions and the modulation of zonula occludens- (ZO-) 1, occludin and claudin-1 expression by estrogen in castrated female rat vagina. Female Sprague-Dawley rats (230–240 g, n = 45) were divided into three groups and subjected to a sham operation (control group, n = 15), bilateral ovariectomy (Ovx group, n = 15), or bilateral ovariectomy followed by daily subcutaneous injection of 17β-estradiol (50 μg/kg/day, Ovx + Est group, n = 15). The cellular localization and expression of ZO-1, occludin, and claudin-1 were determined in each group by immunohistochemistry and western blot. Results. Expression of ZO-1 was diffuse in all groups, with the highest intensity in the superficial epithelium in the control group. Occludin was localized in the intermediate and basal epithelium. Claudin-1 was most intense in the superficial layer of the vaginal epithelium in the control group. Expression of ZO-1, occludin, and claudin-1 was significantly decreased after ovariectomy and was restored to the level of the control after estrogen replacement. Conclusions. Tight junctions are distinctly localized in rat vagina, and estrogen modulates the expression of tight junctions. Further researches are needed to clarify the functional role of tight junctions in vaginal lubrication. PMID:27127786

  18. Superfast computations of dual and tight Gabor atoms

    NASA Astrophysics Data System (ADS)

    Qiu, Sigang

    1995-09-01

    We consider a class of Gabor-type matrices and develop simplified Gabor-type matrix operations. As applications to discrete Gabor transforms, we propose `superfast' algorithms for determining the inverse of Gabor frame operators and the square roots of the Gabor frame operators as well as the dual Gabor and tight Gabor atoms. Besides, we summarize briefly some additional results.

  19. Aspirator modification for the removal of mosquitoes from tight spaces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An insect aspirator was modified to remove mosquitoes that entered an animal-baited experimental cage-within-a-cage. The modified aspirator is easy to maneuver inside tight spaces, powerful enough to aspirate mosquitoes but not remove scales or fluorescent marking powders, and will run continuously...

  20. Si Tight-Binding Parameters from Genetic Algorithm Fitting

    NASA Technical Reports Server (NTRS)

    Klimeck, G.; Bowen, R.; Boykin, T.; Salazar-Lazaro, C.; Cwik, T.; Stoica, A.

    1999-01-01

    Quantum mechanical simulations of carrier transport in Si require an accurate model of the complicated Si bandstructure. Tight-binding models are an attractive method of choice since they bear the full electronic structure symmetry in them and they can discretize a realistic device on an atomic scale.

  1. Method of making pressure tight seal for super alloy

    NASA Technical Reports Server (NTRS)

    Little, R. E. (Inventor)

    1973-01-01

    A procedure for forming a pressure tight seal along two edges of super alloy sheets is presented. The procedure consists of flame spraying a powdered aluminum-nickel composition on the joint. The use of frozen carbon dioxide and carbon dioxide gas to maintain a low temperature environment during the flame spraying is described.

  2. Predictor variables for forward scapular posture including posterior shoulder tightness.

    PubMed

    Lee, Ji-Hyun; Cynn, Heon-seock; Yi, Chung-Hwi; Kwon, Oh-yun; Yoon, Tae-Lim

    2015-04-01

    The purpose of this study was (1) to determine the relationships between the degree of forward scapular posture and the pectoralis minor index, the strength of the serratus anterior, the thoracic spine angle, and posterior shoulder tightness, and (2) to identify predictors of forward scapular posture, including posterior shoulder tightness. The study recruited eighteen subjects with forward scapular posture and objectively measured the acromion distance, the pectoralis minor index, and the strength of the serratus anterior muscle of each participant. The amount of glenohumeral horizontal adduction and internal rotation were evaluated to measure posterior shoulder tightness. There were high intra-rater reliabilities in all measurements. The measurement results showed a statistically strong negative correlation between the degree of forward scapular posture and the pectoralis minor index. They also revealed a moderate positive correlation between the degree of forward scapular posture and the thoracic spine angle and a moderate negative relationship between the degree of forward scapular posture and the amount of the glenohumeral horizontal adduction. A multiple regression analysis indicated that a total multiple regression model explained 93% of the amount of forward scapular posture. All predictor variables, including posterior shoulder tightness, should be considered while assessing, managing, and preventing forward scapular posture. PMID:25892380

  3. In-house development of an optimized synthetic module for routine [11C]acetate production

    PubMed Central

    Jang, Hwa Youn; Kwon, Seong Young; Pyo, Ayoung; Hur, Min Goo; Kim, Sang Wook; Park, Jeong-Hoon; Kim, Hee-Jung; Yang, Seung Dae; Lee, Sunwoo; Kim, Dong-Yeon

    2015-01-01

    [11C]Acetate, a radiotracer for PET imaging, is a promising radiopharmaceutical for overcoming the limitation of 2-deoxy-2-[18F]fluoro-d-glucose in a number of cancers. Here, the optimized automatic synthesis of [11C]acetate using an in-house-developed module under different conditions has been reported for routine production. [11C]CO2 was produced in a 16.4 MeV PETtrace cyclotron, and methyl magnesium chloride was used for synthesis. For product purification, ion-exchange solid-phase extraction cartridges were used, connected in series. High-performance liquid chromatography and gas chromatography were used to measure radiochemical and chemical purity. The Limulus amebocyte lysate test and the fluid thioglycollate medium test were performed for quality control of [11C]acetate. The total reaction time of [11C]acetate was within 15 min, and the overall decay-corrected radiochemical yield was 84.33±8.85%. Radiochemical purity was greater than 98% when evaluated on an analytical high-performance liquid chromatography system. No endotoxins or anaerobic bacteria were seen on quality control checks. Optimized production of [11C]acetate was achieved by the in-house module. Radiochemical and biological properties of the [11C]acetate produced were appropriate for clinical PET study. PMID:25244351

  4. Megestrol acetate for treatment of endometriosis.

    PubMed

    Schlaff, W D; Dugoff, L; Damewood, M D; Rock, J A

    1990-04-01

    Between 1977-1989, 29 women with symptomatic endometriosis were treated with megestrol acetate by the Johns Hopkins Division of Reproductive Endocrinology. All had previously received one or more alternative medical treatments for endometriosis, in each case discontinued because of poor response or development of unacceptable side effects. Treatment consisted of a daily dose of 40 mg megestrol acetate orally for up to 24 months. Disease-related symptoms (dysmenorrhea, noncyclic pelvic pain, and dyspareunia) were relieved in 86% of the subjects treated with an adequate course of therapy. Side effects were fairly well tolerated, although eight women discontinued treatment within 2 months and two others stopped the drug by 4 months. These preliminary findings suggest that megestrol acetate may be an effective treatment for patients with endometriosis, even those who have been unresponsive to other modes of therapy. PMID:2314784

  5. Human alveolar epithelial cells expressing tight junctions to model the air-blood barrier.

    PubMed

    Kuehn, Anna; Kletting, Stephanie; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Griffiths, Gareth; Fischer, Ulrike; Meese, Eckart; Huwer, Hanno; Wirth, Dagmar; May, Tobias; Schneider-Daum, Nicole; Lehr, Claus-Michael

    2016-01-01

    This paper describes a new human alveolar epithelial cell line (hAELVi - human Alveolar Epithelial Lentivirus immortalized) with type I-like characteristics and functional tight junctions, suitable to model the air-blood barrier of the peripheral lung. Primary human alveolar epithelial cells were immortalized by a novel regimen, grown as monolayers on permeable filter supports and characterized morphologically, biochemically and biophysically. hAELVi cells maintain the capacity to form tight intercellular junctions, with high trans-epithelial electrical resistance (> 1000 Ω*cm²). The cells could be kept in culture over several days, up to passage 75, under liquid-liquid as well as air-liquid conditions. Ultrastructural analysis and real time PCR revealed type I-like cell properties, such as the presence of caveolae, expression of caveolin-1, and absence of surfactant protein C. Accounting for the barrier properties, inter-digitations sealed with tight junctions and desmosomes were also observed. Low permeability of the hydrophilic marker sodium fluorescein confirmed the suitability of hAELVi cells for in vitro transport studies across the alveolar epithelium. These results suggest that hAELVi cells reflect the essential features of the air-blood barrier, as needed for an alternative to animal testing to study absorption and toxicity of inhaled drugs, chemicals and nanomaterials. PMID:26985677

  6. Secretion of Alpha-Hemolysin by Escherichia coli Disrupts Tight Junctions in Ulcerative Colitis Patients

    PubMed Central

    Mirsepasi-Lauridsen, Hengameh Chloé; Du, Zhengyu; Struve, Carsten; Charbon, Godefroid; Karczewski, Jurgen; Krogfelt, Karen Angeliki; Petersen, Andreas Munk; Wells, Jerry M

    2016-01-01

    Objectives: The potential of Escherichia coli (E. coli) isolated from inflammatory bowel disease (IBD) patients to damage the integrity of the intestinal epithelium was investigated. Methods: E. coli strains isolated from patients with ulcerative colitis (UC) and healthy controls were tested for virulence capacity by molecular techniques and cytotoxic assays and transepithelial electric resistance (TER). E. coli isolate p19A was selected, and deletion mutants were created for alpha-hemolysin (α-hemolysin) (hly) clusters and cytotoxic necrotizing factor type 1 (cnf1). Probiotic E. coli Nissle and pathogenic E. coli LF82 were used as controls. Results: E. coli strains from patients with active UC completely disrupted epithelial cell tight junctions shortly after inoculation. These strains belong to phylogenetic group B2 and are all α-hemolysin positive. In contrast, probiotic E. coli Nissle, pathogenic E. coli LF82, four E. coli from patients with inactive UC and three E. coli strains from healthy controls did not disrupt tight junctions. E. coli p19A WT as well as cnf1, and single loci of hly mutants from cluster I and II were all able to damage Caco-2 (Heterogeneous human epithelial colorectal adenocarcinoma) cell tight junctions. However, this phenotype was lost in a mutant with knockout (Δ) of both hly loci (P<0.001). Conclusions: UC-associated E. coli producing α-hemolysin can cause rapid loss of tight junction integrity in differentiated Caco-2 cell monolayers. This effect was abolished in a mutant unable to express α-hemolysin. These results suggest that high Hly expression may be a mechanism by which specific strains of E. coli pathobionts can contribute to epithelial barrier dysfunction and pathophysiology of disease in IBD. PMID:26938480

  7. Synthesis of Cellulose Acetate from Cotton Byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton burr and cottonseed hull are relatively inexpensive cotton byproducts. In an effort to derive greater value out of these natural renewable materials, we have succeeded in converting part of them into cellulose acetate without prior chemical breakdown or physical separation of cellulose, ligni...

  8. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium acetate. 184.1185 Section 184.1185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  9. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs §...

  10. 21 CFR 522.1881 - Prednisolone acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Prednisolone acetate. 522.1881 Section 522.1881 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... used as supportive therapy pre- and postoperatively and for various stress conditions...

  11. Fragrance material review on phenethyl acetate.

    PubMed

    McGinty, D; Vitale, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of phenethyl acetate when used as a fragrance ingredient is presented. Phenethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for phenethyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, toxicokinetics, repeated dose, genotoxicity, and carcinogenicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414644

  12. Reactions of germanium tetrahalides with ketene acetals

    SciTech Connect

    Efimova, I.V.; Kazankova, M.A.; Lutsenko, I.F.

    1985-05-01

    Recently, the authors reported that alkyl vinyl ethers and terminal alkynes are readily germylated by germanium tetrahalides in the presence of a tertiary amine. To extend the range of applicability of this reaction and to obtain additional information on its mechanism, the authors study reactions of ketene acetals with germanium tetrachloride and tetrabromide in the presence of triethylamine.

  13. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  14. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-02-17

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85 and 200 C and removing the reaction products from the contact zone.

  15. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.

  16. Differences between tight and loose cultures: a 33-nation study.

    PubMed

    Gelfand, Michele J; Raver, Jana L; Nishii, Lisa; Leslie, Lisa M; Lun, Janetta; Lim, Beng Chong; Duan, Lili; Almaliach, Assaf; Ang, Soon; Arnadottir, Jakobina; Aycan, Zeynep; Boehnke, Klaus; Boski, Pawel; Cabecinhas, Rosa; Chan, Darius; Chhokar, Jagdeep; D'Amato, Alessia; Ferrer, Montse; Fischlmayr, Iris C; Fischer, Ronald; Fülöp, Marta; Georgas, James; Kashima, Emiko S; Kashima, Yoshishima; Kim, Kibum; Lempereur, Alain; Marquez, Patricia; Othman, Rozhan; Overlaet, Bert; Panagiotopoulou, Penny; Peltzer, Karl; Perez-Florizno, Lorena R; Ponomarenko, Larisa; Realo, Anu; Schei, Vidar; Schmitt, Manfred; Smith, Peter B; Soomro, Nazar; Szabo, Erna; Taveesin, Nalinee; Toyama, Midori; Van de Vliert, Evert; Vohra, Naharika; Ward, Colleen; Yamaguchi, Susumu

    2011-05-27

    With data from 33 nations, we illustrate the differences between cultures that are tight (have many strong norms and a low tolerance of deviant behavior) versus loose (have weak social norms and a high tolerance of deviant behavior). Tightness-looseness is part of a complex, loosely integrated multilevel system that comprises distal ecological and historical threats (e.g., high population density, resource scarcity, a history of territorial conflict, and disease and environmental threats), broad versus narrow socialization in societal institutions (e.g., autocracy, media regulations), the strength of everyday recurring situations, and micro-level psychological affordances (e.g., prevention self-guides, high regulatory strength, need for structure). This research advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change. PMID:21617077

  17. Air quality in tightly sealed and passive homes

    SciTech Connect

    Scott, L.A.

    1981-09-01

    Indoor air quality has attracted increasing attention during the past few yars. Pollutants generated from combustion, building materials, and human activities may reach significant levels in the indoor environment to produce adverse health effects. This report deals with the classes of pollutants and their sources, and the significance of reported levels, possible health effects, and control strategies in relation to tightly sealed and passive solar construction techniques. In tightly sealed homes, residential air-to-air heat exchangers, whose design and performance are discussed, offer one method of improving air quality at reasonable cost. It is recommended that further research be implemented to identify hazardous concentrations of pollutants and set standards to minimize health impacts in the search for new energy innovations.

  18. Enteropathogenic E. coli: breaking the intestinal tight junction barrier

    PubMed Central

    Singh, Anand Prakash; Aijaz, Saima

    2016-01-01

    Enteropathogenic E. coli (EPEC) causes acute intestinal infections in infants in the developing world. Infection typically spreads through contaminated food and water and leads to severe, watery diarrhea. EPEC attaches to the intestinal epithelial cells and directly injects virulence factors which modulate multiple signaling pathways leading to host cell dysfunction. However, the molecular mechanisms that regulate the onset of diarrhea are poorly defined. A major target of EPEC is the host cell tight junction complex which acts as a barrier and regulates the passage of water and solutes through the paracellular space. In this review, we focus on the EPEC effectors that target the epithelial barrier, alter its functions and contribute to leakage through the tight junctions. PMID:27239268

  19. A tightly inducible riboswitch system in Synechocystis sp. PCC 6803.

    PubMed

    Ohbayashi, Ryudo; Akai, Hideto; Yoshikawa, Hirofumi; Hess, Wolfgang R; Watanabe, Satoru

    2016-07-14

    Cyanobacteria are photosynthetic microorganisms that serve as experimental model organisms for the study of photosynthesis, environmental stress responses, and the production of biofuels. Genetic tools for bioengineering have been developed as a result of such studies. However, there is still room for improvement for the tight control of experimental protein expression in these microorganisms. Here, we describe an expression system controlled by a theophylline-responsive riboswitch that we have constructed in the cyanobacterium Synechocystis sp. PCC 6803. We demonstrate that, in response to different theophylline concentrations, this riboswitch can tightly control green fluorescence protein expression in Synechocystis. Thus, this system is useful as a tool for genetic engineering and the synthetic biology of cyanobacteria. PMID:27250662

  20. Extensor Pollicis Longus Rupture after Mini TightRope Suspensionplasty.

    PubMed

    Seetharaman, Mani; Vitale, Mark A; Desai, Kapil; Crowe, John F

    2016-05-01

    Background Arthritis of the first carpometacarpal (CMC) joint has been surgically treated in multiple ways with varying levels of success as measured by subjective and objective measures. Trapeziectomy with numerous variations in suspensionplasty comprises one of the more commonly used surgical procedures. Recently, the Mini TightRope apparatus has been utilized as a new method for achieving suspensionplasty, and as such lacks significant review of use and safety in the literature. Case Description An extensor pollicis longus (EPL) rupture following a trapeziectomy and Mini TightRope suspensionplasty for CMC arthritis of the thumb is presented. The patient successfully underwent an extensor indicis proprius (EIP) to EPL transfer to treat this complication. Literature Review There is well-established documentation of injury to the extensor tendons from orthopedic hardware such as volar locking plates. Regarding use of the Mini TightRope apparatus, guidelines for placement of the suture button include caution to place the button away from the EPL tendon to minimize the chance of tendon irritation. Additionally, FiberWire sutures, a component of the apparatus, have been shown to demonstrate soft tissue reactions with adjacent inflammatory response. Published reports on adverse events utilizing this device have been limited to case reports including an index metacarpal fracture. Clinical Relevance The aim of this case report was to cite an occurrence of EPL rupture following its use and discuss the possibilities of its direct contribution. PMID:27104081

  1. Tight junction regulates epidermal calcium ion gradient and differentiation

    SciTech Connect

    Kurasawa, Masumi; Maeda, Tetsuo; Oba, Ai; Yamamoto, Takuya; Sasaki, Hiroyuki

    2011-03-25

    Research highlights: {yields} We disrupted epidermal tight junction barrier in reconstructed epidermis. {yields} It altered Ca{sup 2+} distribution and consequentially differentiation state as well. {yields} Tight junction should affect epidermal homeostasis by maintaining Ca{sup 2+} gradient. -- Abstract: It is well known that calcium ions (Ca{sup 2+}) induce keratinocyte differentiation. Ca{sup 2+} distributes to form a vertical gradient that peaks at the stratum granulosum. It is thought that the stratum corneum (SC) forms the Ca{sup 2+} gradient since it is considered the only permeability barrier in the skin. However, the epidermal tight junction (TJ) in the granulosum has recently been suggested to restrict molecular movement to assist the SC as a secondary barrier. The objective of this study was to clarify the contribution of the TJ to Ca{sup 2+} gradient and epidermal differentiation in reconstructed human epidermis. When the epidermal TJ barrier was disrupted by sodium caprate treatment, Ca{sup 2+} flux increased and the gradient changed in ion-capture cytochemistry images. Alterations of ultrastructures and proliferation/differentiation markers revealed that both hyperproliferation and precocious differentiation occurred regionally in the epidermis. These results suggest that the TJ plays a crucial role in maintaining epidermal homeostasis by controlling the Ca{sup 2+} gradient.

  2. Tightly Coupled Inertial Navigation System/Global Positioning System (TCMIG)

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Jackson, Kurt (Technical Monitor)

    2002-01-01

    Many NASA applications planned for execution later this decade are seeking high performance, miniaturized, low power Inertial Management Units (IMU). Much research has gone into Micro-Electro-Mechanical System (MEMS) over the past decade as a solution to these needs. While MEMS devices have proven to provide high accuracy acceleration measurements, they have not yet proven to have the accuracy required by many NASA missions in rotational measurements. Therefore, a new solution has been formulated integrating the best of all IMU technologies to address these mid-term needs in the form of a Tightly Coupled Micro Inertial Navigation System (INS)/Global Positioning System (GPS) (TCMIG). The TCMIG consists of an INS and a GPS tightly coupled by a Kalman filter executing on an embedded Field Programmable Gate Array (FPGA) processor. The INS consists of a highly integrated Interferometric Fiber Optic Gyroscope (IFOG) and a MEMS accelerometer. The IFOG utilizes a tightly wound fiber coil to reduce volume and the high level of integration and advanced optical components to reduce power. The MEMS accelerometer utilizes a newly developed deep etch process to increase the proof mass and yield a highly accurate accelerometer. The GPS receiver consists of a low power miniaturized version of the Blackjack receiver. Such an IMU configuration is ideal to meet the mid-term needs of the NASA Science Enterprises and the new launch vehicles being developed for the Space Launch Initiative (SLI).

  3. Ab initio tight-binding Hamiltonian for transition metal dichalcogenides

    NASA Astrophysics Data System (ADS)

    Fang, Shiang; Kuate Defo, Rodrick; Shirodkar, Sharmila N.; Lieu, Simon; Tritsaris, Georgios A.; Kaxiras, Efthimios

    2015-11-01

    We present an accurate ab initio tight-binding Hamiltonian for the transition metal dichalcogenides, MoS2, MoSe2, WS2, WSe2, with a minimal basis (the d orbitals for the metal atoms and p orbitals for the chalcogen atoms) based on a transformation of the Kohn-Sham density functional theory Hamiltonian to a basis of maximally localized Wannier functions. The truncated tight-binding Hamiltonian, with only on-site, first, and partial second neighbor interactions, including spin-orbit coupling, provides a simple physical picture and the symmetry of the main band-structure features. Interlayer interactions between adjacent layers are modeled by transferable hopping terms between the chalcogen p orbitals. The full-range tight-binding Hamiltonian can be reduced to hybrid-orbital k .p effective Hamiltonians near the band extrema that capture important low-energy excitations. These ab initio Hamiltonians can serve as the starting point for applications to interacting many-body physics including optical transitions and Berry curvature of bands, of which we give some examples.

  4. Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.

    ERIC Educational Resources Information Center

    Hocking, M. B.

    1980-01-01

    Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)

  5. Accurate vibrational frequencies using the self-consistent-charge density-functional tight-binding method

    NASA Astrophysics Data System (ADS)

    Małolepsza, Edyta; Witek, Henryk A.; Morokuma, Keiji

    2005-09-01

    An optimization technique for enhancing the quality of repulsive two-body potentials of the self-consistent-charge density-functional tight-binding (SCC-DFTB) method is presented and tested. The new, optimized potentials allow for significant improvement of calculated harmonic vibrational frequencies. Mean absolute deviation from experiment computed for a group of 14 hydrocarbons is reduced from 59.0 to 33.2 cm -1 and maximal absolute deviation, from 436.2 to 140.4 cm -1. A drawback of the new family of potentials is a lower quality of reproduced geometrical and energetic parameters.

  6. 21 CFR 582.5892 - a-Tocopherol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5892 a-Tocopherol acetate. (a) Product. a-Tocopherol acetate. (b) Conditions of use....

  7. Expression of acetate permease-like (apl) genes in subsurface communities of Geobacter species under fluctuating acetate concentrations

    SciTech Connect

    Elifantz, H.; N'Guessan, L.A.; Mouser, P.J.; Williams, K H.; Wilkins, M J.; Risso, C.; Holmes, D.E.; Long, P.E.; Lovley, D.R.

    2010-03-01

    The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2-10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

  8. Expression of Acetate Permease-like (apl) Genes in Subsurface Communities of Geobacter Species Under Fluctuating Acetate Concentrations

    SciTech Connect

    Elifantz, H; N'Guessan, A L; Mouser, Paula; Williams, Kenneth H; Wilkins, Michael J; Risso, Carla; Holmes, Dawn; Long, Philip E; Lovley, Derek R

    2010-09-01

    The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2–10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

  9. Separating acetic acid from furol (furfural) by electrodialysis method

    SciTech Connect

    Guan, S.F.; Li, C.S. Ye, S.T.; Shen, S.Y.; Wang, Y.T.; Yu, S.H.

    1981-01-01

    Furfural production by hydrolysis of fibrous plant materials is accompanied by formation of acetic acid in amounts depending on the material used. The amount of acetic formed in the hydrolysis of the fruit shell of oil-tea camellia (Camellia oleosa) (an oilseed-bearing tree) is equal to the amount of furfural. The acetic acid can be separated from the furfural and concentrated to 10% by electrodialysis. A smaller amount of furfural is separated with acetic acid.

  10. Cyproterone acetate in treatment of precocious puberty.

    PubMed Central

    Kauli, R; Pertzelan, A; Prager-Lewin, R; Grünebaum, M; Laron, Z

    1976-01-01

    Twenty-nine children (23 girls, 6 boys) with precocious puberty were treated with cyproterone acetate for various periods of time ranging from 6 months to 3 years 4 months. They received an oral dose ranging from 70-150 mg/m2 per day, or an intramuscular depot injection once a fortnight or once a month at a dose ranging from 107-230 mg/m2. Both forms of therapy were found to suppress the signs of sexual maturation, but the oral form proved to be superior. Only the younger patients with a bone age under 11 years showed a beneficial effect upon linear growth and bone maturation. No side effects were noted, but additional advantageous effects upon behaviour and sociability were. It is concluded that at present cyproterone acetate by mouth is the drug of choice in the treatment of precocious puberty. The treatment should be initiated as early as possible to attain maximum benefit. PMID:952553

  11. Facile hydrolysis and alcoholysis of palladium acetate.

    PubMed

    Bedford, Robin B; Bowen, John G; Davidson, Russell B; Haddow, Mairi F; Seymour-Julen, Annabelle E; Sparkes, Hazel A; Webster, Ruth L

    2015-05-26

    Palladium(II) acetate is readily converted into [Pd3 (μ(2) -OH)(OAc)5 ] (1) in the presence of water in a range of organic solvents and is also slowly converted in the solid state. Complex 1 can also be formed in nominally anhydrous solvents. Similarly, the analogous alkoxide complexes [Pd3 (μ(2) -OR)(OAc)5 ] (3) are easily formed in solutions of palladium(II) acetate containing a range of alcohols. An examination of a representative Wacker-type oxidation shows that the Pd-OH complex 1 and a related Pd-oxo complex 4 can be excluded as potential catalytic intermediates in the absence of exogenous water. PMID:25865439

  12. The Antibacterial Activity of Acetic Acid against Biofilm-Producing Pathogens of Relevance to Burns Patients

    PubMed Central

    Halstead, Fenella D.; Rauf, Maryam; Moiemen, Naiem S.; Bamford, Amy; Wearn, Christopher M.; Fraise, Adam P.; Lund, Peter A.; Oppenheim, Beryl A.; Webber, Mark A.

    2015-01-01

    Introduction Localised infections, and burn wound sepsis are key concerns in the treatment of burns patients, and prevention of colonisation largely relies on biocides. Acetic acid has been shown to have good antibacterial activity against various planktonic organisms, however data is limited on efficacy, and few studies have been performed on biofilms. Objectives We sought to investigate the antibacterial activity of acetic acid against important burn wound colonising organisms growing planktonically and as biofilms. Methods Laboratory experiments were performed to test the ability of acetic acid to inhibit growth of pathogens, inhibit the formation of biofilms, and eradicate pre-formed biofilms. Results Twenty-nine isolates of common wound-infecting pathogens were tested. Acetic acid was antibacterial against planktonic growth, with an minimum inhibitory concentration of 0.16–0.31% for all isolates, and was also able to prevent formation of biofilms (at 0.31%). Eradication of mature biofilms was observed for all isolates after three hours of exposure. Conclusions This study provides evidence that acetic acid can inhibit growth of key burn wound pathogens when used at very dilute concentrations. Owing to current concerns of the reducing efficacy of systemic antibiotics, this novel biocide application offers great promise as a cheap and effective measure to treat infections in burns patients. PMID:26352256

  13. Thermochemical characteristics of cellulose acetates with different degrees of acetylation

    NASA Astrophysics Data System (ADS)

    Larina, V. N.; Ur'yash, V. F.; Kushch, D. S.

    2012-12-01

    The standard enthalpies of combustion and formation of cellulose acetates with different degrees of acetylation are determined. It is established that there is a proportional dependence of these thermochemical characteristics vs. the degree of acetylation, weight fraction of bonded acetic acid, and molar mass of the repeating unit of cellulose acetates.

  14. Acetate concentrations and oxidation in salt marsh sediments

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Acetate concentrations and rates of acetate oxidation and sulfate reduction were measured in S. alterniflora sediments in New Hampshire and Massachusetts. Pore water extracted from cores by squeezing or centrifugation contained in greater than 0.1 mM acetate and, in some instances, greater than 1.0 mM. Pore water sampled nondestructively contained much less acetate, often less than 0.01 mM. Acetate was associated with roots, and concentrations varied with changes in plant physiology. Acetate turnover was very low whether whole core or slurry incubations were used. Radiotracers injected directly into soils yielded rates of sulfate reduction and acetate oxidation not significantly different from core incubation techniques. Regardless of incubation method, acetate oxidation did not account for a substantial percentage of sulfate reduction. These results differ markedly from data for unvegetated coastal sediments where acetate levels are low, oxidation rate constants are high, and acetate oxication rates greatly exceed rates of sulfate reduction. The discrepancy between rates of acetate oxidation and sulfate reduction in these marsh soils may be due either to the utilization of substrates other than acetate by sulfate reducers or artifacts associated with measurements of organic utilization by rhizosphere bacteria. Care must be taken when interpreting data from salt marsh sediments since the release of material from roots during coring may affect the concentrations of certain compounds as well as influencing results obtained when sediment incubations are employed.

  15. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ethyl alcohol containing ethyl acetate....

  16. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ethyl alcohol containing ethyl acetate....

  17. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ethyl alcohol containing ethyl acetate....

  18. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl alcohol containing ethyl acetate....

  19. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ethyl alcohol containing ethyl acetate....

  20. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    ERIC Educational Resources Information Center

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  1. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  2. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  3. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  4. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  5. 21 CFR 582.5933 - Vitamin A acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  6. Co-fermentation of acetate and sugars facilitating microbial lipid production on acetate-rich biomass hydrolysates.

    PubMed

    Gong, Zhiwei; Zhou, Wenting; Shen, Hongwei; Yang, Zhonghua; Wang, Guanghui; Zuo, Zhenyu; Hou, Yali; Zhao, Zongbao K

    2016-05-01

    The process of lignocellulosic biomass routinely produces a stream that contains sugars plus various amounts of acetic acid. As acetate is known to inhibit the culture of microorganisms including oleaginous yeasts, little attention has been paid to explore lipid production on mixtures of acetate and sugars. Here we demonstrated that the yeast Cryptococcus curvatus can effectively co-ferment acetate and sugars for lipid production. When mixtures of acetate and glucose were applied, C. curvatus consumed both substrates simultaneously. Similar phenomena were also observed for acetate and xylose mixtures, as well as acetate-rich corn stover hydrolysates. More interestingly, the replacement of sugar with equal amount of acetate as carbon source afforded higher lipid titre and lipid content. The lipid products had fatty acid compositional profiles similar to those of cocoa butter, suggesting their potential for high value-added fats and biodiesel production. This co-fermentation strategy should facilitate lipid production technology from lignocelluloses. PMID:26874438

  7. Corrosion behavior of ASTM A106 and AISI 316SS in KOH and nickel acetate solutions

    SciTech Connect

    Gonzalez, J.J.; Baron, E.; Saldeho, J.

    1999-11-01

    The present work is concerned with the corrosion behavior of ASTM A106 B grade and AISI 316 stainless steel in the presence of three different environments: a mixture or an emulsion formed by oil-KOH-nickel acetate solution, a KOH (40 wt. %) solution and a nickel acetate (14 wt. %) solution, which are representative fluids used during a PDVSA proprietary process for improving heavy crude oils. Corrosion rate measurements and stress corrosion cracking (SCC) behavior were evaluated through weight loss (in the laboratory and in situ measurements), and mechanical testing (constant load and slow strain rate tests). In the emulsion the corrosion rate was almost undetectable for both steels and the evidence suggested that no SCC had taken place. However, the corrosion rate of the carbon steel in 40wt.% KOH solution at 130 C was 2.8 mm/y, showing the presence of pitting corrosion. On the other hand, the stainless steel showed an undetectable corrosion rate. Though SCC was not observed in any of the materials tested in presence of KOH at both 30 and 130 C, a deterioration in the mechanical properties was found for the high temperature case for carbon steel. During nickel acetate solution tests at 130 C, the A 106 steel showed a relatively high corrosion rate (5.9 mm/y) and the formation of pits. For the stainless steel case, acetate solution had no corrosive effect whatsoever. This last environment offered no SCC susceptibility for any material at both temperatures tested.

  8. Transferable tight-binding parameters: An application to Ni and Ni-Al alloys

    SciTech Connect

    Sluiter, M.H.F.; Singh, P.P.

    1993-07-01

    Two approaches for obtaining tight-binding parameters for metallic alloys are compared and contrasted with special regard for the application to large scale simulations such as may occur in tight-binding molecular dynamics studies.

  9. Testing.

    ERIC Educational Resources Information Center

    Killoran, James, Ed.

    1984-01-01

    This journal issue addresses the issue of testing in the social studies classroom. The first article, "The Role of Testing" (Bragaw), focuses on the need for tests to reflect the objectives of the study completed. The varying functions of pop quizzes, weekly tests, and unit tests are explored. "Testing Thinking Processes" (Killoran, Zimmer, and…

  10. Tight-binding approach to strain-dependent DNA electronics

    NASA Astrophysics Data System (ADS)

    Malakooti, Sadeq; Hedin, Eric; Joe, Yong

    2013-07-01

    Small mechanical strain perturbations are considered in calculations of the poly(G)-poly(C) DNA molecular electronic structure, using a tight-binding framework in conjunction with the theories of Slater-Koster and linear elasticity. Results reveal a strain-induced band gap for DNA which is linearly dependent on the induced strain. Local density of states calculations expose that the contribution of the guanine-cytosine base pairs in the charge transport mechanism is significantly enhanced relative to the backbones when DNA is compressed. Transport investigations also disclose a strain-induced metal-semiconductor transition for the DNA molecule, which suggests possible potential uses for sensing applications.

  11. Tight Lower Bound for Percolation Threshold on an Infinite Graph

    NASA Astrophysics Data System (ADS)

    Hamilton, Kathleen E.; Pryadko, Leonid P.

    2014-11-01

    We construct a tight lower bound for the site percolation threshold on an infinite graph, which becomes exact for an infinite tree. The bound is given by the inverse of the maximal eigenvalue of the Hashimoto matrix used to count nonbacktracking walks on the original graph. Our bound always exceeds the inverse spectral radius of the graph's adjacency matrix, and it is also generally tighter than the existing bound in terms of the maximum degree. We give a constructive proof for existence of such an eigenvalue in the case of a connected infinite quasitransitive graph, a graph-theoretic analog of a translationally invariant system.

  12. Tight glycemic control in the ICU - is the earth flat?

    PubMed

    Steil, Garry M; Agus, Michael S D

    2014-01-01

    Tight glycemic control in the ICU has been shown to reduce mortality in some but not all prospective randomized control trials. Confounding the interpretation of these studies are differences in how the control was achieved and underlying incidence of hypoglycemia, which can be expected to be affected by the introduction of continuous glucose monitoring (CGM). In this issue of Critical Care, a consensus panel provides a list of the research priorities they believe are needed for CGM to become routine practice in the ICU. We reflect on these recommendations and consider the implications for using CGM today. PMID:25041720

  13. Effects of gastrocnemius tightness on forefoot during gait.

    PubMed

    Cazeau, Cyrille; Stiglitz, Yves

    2014-12-01

    The gastrocnemius is the main muscle of the posterior compartment of the leg. As a biarticular muscle it has specific biomechanical propertiess. This article discusses these properties combining the major biomechanical topics of anatomy, dynamics, kinetics, and electromyography. This muscle is remarkable in that it has very low energy consumption and very high mechanical efficacy. In addition to the biomechanical features, the consequences of its tightness are discussed. The dysfunction also appears in all the biomechanical topics and clarifies the reasons of the location of symptoms in the midfoot and on the plantar aspect of the forefoot. PMID:25456714

  14. Materials processing with a tightly focused femtosecond laser vortex pulse.

    PubMed

    Hnatovsky, Cyril; Shvedov, Vladlen G; Krolikowski, Wieslaw; Rode, Andrei V

    2010-10-15

    In this Letter we present the first (to our knowledge) demonstration of material modification using tightly focused single femtosecond laser vortex pulses. Double-charge femtosecond vortices were synthesized with a polarization-singularity beam converter based on light propagation in a uniaxial anisotropic medium and then focused using moderate- and high-NA optics (viz., NA=0.45 and 0.9) to ablate fused silica and soda-lime glass. By controlling the pulse energy, we consistently machine micrometer-size ring-shaped structures with <100nm uniform groove thickness. PMID:20967085

  15. Tight-binding molecular-dynamics simulation of buckyball collisions

    SciTech Connect

    Zhang, B.L.; Wang, C.Z.; Chan, C.T.; Ho, K.M. )

    1993-04-01

    The collisions between C[sub 60] molecules are studied by tight-binding molecular-dynamics simulations. We observe three different regimes of behavior as the collisions become more and more energetic: bouncing, fusion, and fragmentation. The critical energies for fusion and fragmentation as well as details of the energy transfer during the collision process for the bouncing regime are investigated. The collisions at several specific energies and orientations produce interesting novel molecules, such as small baby cages, caps, and even a Russian-Doll molecule in which a small cage is trapped in a bigger one. 28 refs., 5 figs., 2 tabs.

  16. Tight-binding model for hydrogen-silicon interactions

    SciTech Connect

    Min, B.J.; Lee, Y.H.; Wang, C.Z.; Chan, C.T.; Ho, K.M. Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 )

    1992-03-15

    We have developed an empirical tight-binding model for use in molecular-dynamics simulations to study hydrogen-silicon systems. The hydrogen-silicon interaction is constructed to reproduce the electronic energy levels and vibration frequencies of silane (SiH{sub 4}). Further use of the model in the studies of disilane (Si{sub 2}H{sub 6}) and of hydrogen on the Si(111) surface also yields results in good agreement with first-principles calculations and experiments.

  17. Strained graphene: tight-binding and density functional calculations

    NASA Astrophysics Data System (ADS)

    Ribeiro, R. M.; Pereira, Vitor M.; Peres, N. M. R.; Briddon, P. R.; Castro Neto, A. H.

    2009-11-01

    We determine the band structure of graphene under strain using density functional calculations. The ab initio band structure is then used to extract the best fit to the tight-binding hopping parameters used in a recent microscopic model of strained graphene. It is found that the hopping parameters may increase or decrease upon increasing strain, depending on the orientation of the applied stress. The fitted values are compared with an available parameterization for the dependence of the orbital overlap on the distance separating the two carbon atoms. It is also found that strain does not induce a gap in graphene, at least for deformations up to 10%.

  18. Application of cellulose acetate for controlled release of thymol.

    PubMed

    Milovanovic, Stoja; Markovic, Darka; Aksentijevic, Ksenija; Stojanovic, Dusica B; Ivanovic, Jasna; Zizovic, Irena

    2016-08-20

    Cellulose acetate (CA) was investigated as a carrier towards development of material with controlled release of thymol as a natural substance with strong antibacterial properties using high pressure techniques. Effect of thymol content on CA was confirmed by SEM, FTIR and DSC methods. Kinetic of thymol release from CA was tested using simulated gastric and intestinal fluids (hydrochloric acid and phosphate buffer saline). Results were correlated with Korsmeyer-Peppas and Weibull model. Depending on the thymol content and chemical nature of the release medium, the time of thymol release varied from one to three days indicating CA as a promising carrier of thymol with potential uses from medicine to agriculture. The impregnated CA showed antibacterial activity against 23 tested bacterial strains including methicillin-resistant Staphylococcus aureus (MRSA) which is particularly important bearing in mind that this strain causes fatal infections in humans and animals. PMID:27178940

  19. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    PubMed

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided. PMID:25575804

  20. Hydration structure of poly(2-methoxyethyl acrylate): comparison with a 2-methoxyethyl acetate model monomer.

    PubMed

    Morita, Shigeaki; Tanaka, Masaru; Kitagawa, Kuniyuki; Ozaki, Yukihiro

    2010-01-01

    We have previously reported the hydration structure of a poly(2-methoxyethyl acrylate) (PMEA) antithrombogenic material. In the present study, the hydration structure of a 2-methoxyethyl acetate (MEAc) model monomer for PMEA was explored by means of attenuated total reflection infrared (ATR-IR) spectroscopy and differential scanning calorimetry (DSC). Water in MEAc does not show an evidence for cold crystallization by DSC, while it was found by ATR-IR spectroscopy that MEAc has a hydration structure similar to that of PMEA at a functional group level. Three different types of hydrated water, tightly bound water, loosely bound water and scarcely bound water, were identified in MEAc, as well as PMEA. It was suggested from the present study that the localized and concentrated water cluster having the three types of hydration structure on the surface of PMEA plays an important role in the biocompatibility. PMID:20566058

  1. Indium acetate toxicity in male reproductive system in rats.

    PubMed

    Lee, Kuo-Hsin; Chen, Hsiu-Ling; Leung, Chung-Man; Chen, Hsin-Pao; Hsu, Ping-Chi

    2016-01-01

    Indium, a rare earth metal characterized by high plasticity, corrosion resistance, and a low melting point, is widely used in the electronics industry, but has been reported to be an environmental pollutant and a health hazard. We designed a study to investigate the effects of subacute exposure of indium compounds on male reproductive function. Twelve-week old male Sprague-Dawley rats were randomly divided into test and control groups, and received weekly intraperitoneal injections of indium acetate (1.5 mg/kg body weight) and normal saline, respectively, for 8 weeks. Serum indium levels, cauda epididymal sperm count, motility, morphology, chromatin DNA structure, mitochondrial membrane potential, oxidative stress, and testis DNA content were investigated. The indium acetate-treated group showed significant reproductive toxicity, as well as an increased percentage of sperm morphology abnormality, chromatin integrity damage, and superoxide anion generation. Furthermore, positive correlations among sperm morphology abnormalities, chromatin DNA damage, and superoxide anion generation were also noted. The results of this study demonstrated the toxic effect of subacute low-dose indium exposure during the period of sexual maturation on male reproductive function in adulthood, through an increase in oxidative stress and sperm chromatin DNA damage during spermiogenesis, in a rodent model. PMID:25044390

  2. Alterations in cell cholesterol content modulate Ca(2+)-induced tight junction assembly by MDCK cells.

    PubMed

    Stankewich, M C; Francis, S A; Vu, Q U; Schneeberger, E E; Lynch, R D

    1996-08-01

    Transepithelial electrical resistance (TER), a measure of tight junction (TJ) barrier function, develops more rapidly and reaches higher values after preincubation of MDCK cells for 24 h with 2 microM Lovastatin (lova), an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase. While this effect was attributed to a 30% fall in cholesterol (CH), possible effects of lova on the supply of prenyl group precursors could not be excluded. In the current study, strategies were devised to examine effects on TER of agents that simultaneously lower CH and increase the flux of intermediates through the CH biosynthetic pathway. Zaragozic acid, 20 microM, an inhibitor of squalene synthase known to increase the synthesis of isoprenoids and levels of prenylated proteins, lowered cell CH by 30% after 24 h, while accelerating development of TER in the same manner as lova. TER was also enhanced, despite a 23% increase in the rate of [3H]acetate incorporation into CH, when total CH was reduced by 45% during a 2-h incubation with 2 mM methyl beta-cyclodextrin (MBCD), an agent that stimulates CH efflux from cells. The fact that the rate of TER development was diminished when cell CH content was elevated by incubation with a complex of CH and MBCD is further evidence that this sterol modulates development of the epithelial barrier. Cell associated CH derived from the complex was similar to endogenous CH with respect to its accessibility to cholesterol oxidase. Lova's effect on TER was diminished when 5 micrograms/mL of CH was added to the medium during the last 11 h of incubation with lova. PMID:8869884

  3. Evaluation of the Sparton tight-tolerance AXBT

    SciTech Connect

    Boyd, J.D.; Linzell, R.S. |

    1993-12-01

    Forty-six near-simultaneous pairs of conductivity - temperature - depth (CTD) and Sparton `tight tolerance` air expendable bathythermograph (AXBT) temperature profiles were obtained in summer 1991 from a location in the Sargasso Sea. The data were analyzed to assess the temperature and depth accuracies of the Sparton AXBTs. The tight-tolerance criterion was not achieved using the manufacturer`s equations but may have been achieved using customized equations computed from the CTD data. The temperature data from the customized equations had a one standard deviation error of 0.13 C. A customized elapsed fall time-to-depth conversion equation was found to be z = 1.620t - 2.2384 x 10(exp -4) t(exp 2) + 1.291 x 10(exp -7) t(exp 3), with z the depth in meters and t the elapsed fall time after probe release in seconds. The standard deviation of the depth error was about 5 m; a rule of thumb for estimating maximum bounds on the depth error below 100 m could be expressed as +/-2% of depth or +/- 10 m, whichever is greater. This equation gave greater depth accuracy than either the manufacturer`s supplied equation or the navy standard equation.

  4. Evaluation of the Sparton tight-tolerance AXBT

    NASA Technical Reports Server (NTRS)

    Boyd, Janice D.; Linzell, Robert S.

    1993-01-01

    Forty-six near-simultaneous pairs of conductivity - temperature - depth (CTD) and Sparton 'tight tolerance' air expendable bathythermograph (AXBT) temperature profiles were obtained in summer 1991 from a location in the Sargasso Sea. The data were analyzed to assess the temperature and depth accuracies of the Sparton AXBTs. The tight-tolerance criterion was not achieved using the manufacturer's equations but may have been achieved using customized equations computed from the CTD data. The temperature data from the customized equations had a one standard deviation error of 0.13 C. A customized elapsed fall time-to-depth conversion equation was found to be z = 1.620t - 2.2384 x 10(exp -4) t(exp 2) + 1.291 x 10(exp -7) t(exp 3), with z the depth in meters and t the elapsed fall time after probe release in seconds. The standard deviation of the depth error was about 5 m; a rule of thumb for estimating maximum bounds on the depth error below 100 m could be expressed as +/-2% of depth or +/- 10 m, whichever is greater. This equation gave greater depth accuracy than either the manufacturer's supplied equation or the navy standard equation.

  5. Instantaneous Observability of Tightly Coupled SINS/GPS during Maneuvers

    PubMed Central

    Jiang, Junxiang; Yu, Fei; Lan, Haiyu; Dong, Qianhui

    2016-01-01

    The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuvers and angle maneuvers, where the translational maneuver and angle maneuver are modeled. A novel instantaneous observability matrix (IOM) based on a reconstructed psi-angle model is proposed to make the theoretical analysis simpler, which starts from the observability definition directly. Based on the IOM, a series of theoretical analysis are performed. Analysis results show that almost all kinds of translational maneuver and angle maneuver can make a three-channel system instantaneously observable, but there is no one translational maneuver or angle maneuver can make a two-channel system instantaneously observable. The system’s performance is investigated when the system is not instantaneously observable. A series of simulation studies based on EKF are performed to confirm the analytic conclusions. PMID:27240369

  6. Instantaneous Observability of Tightly Coupled SINS/GPS during Maneuvers.

    PubMed

    Jiang, Junxiang; Yu, Fei; Lan, Haiyu; Dong, Qianhui

    2016-01-01

    The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuvers and angle maneuvers, where the translational maneuver and angle maneuver are modeled. A novel instantaneous observability matrix (IOM) based on a reconstructed psi-angle model is proposed to make the theoretical analysis simpler, which starts from the observability definition directly. Based on the IOM, a series of theoretical analysis are performed. Analysis results show that almost all kinds of translational maneuver and angle maneuver can make a three-channel system instantaneously observable, but there is no one translational maneuver or angle maneuver can make a two-channel system instantaneously observable. The system's performance is investigated when the system is not instantaneously observable. A series of simulation studies based on EKF are performed to confirm the analytic conclusions. PMID:27240369

  7. Tricellulin deficiency affects tight junction architecture and cochlear hair cells

    PubMed Central

    Nayak, Gowri; Lee, Sue I.; Yousaf, Rizwan; Edelmann, Stephanie E.; Trincot, Claire; Van Itallie, Christina M.; Sinha, Ghanshyam P.; Rafeeq, Maria; Jones, Sherri M.; Belyantseva, Inna A.; Anderson, James M.; Forge, Andrew; Frolenkov, Gregory I.; Riazuddin, Saima

    2013-01-01

    The two compositionally distinct extracellular cochlear fluids, endolymph and perilymph, are separated by tight junctions that outline the scala media and reticular lamina. Mutations in TRIC (also known as MARVELD2), which encodes a tricellular tight junction protein known as tricellulin, lead to nonsyndromic hearing loss (DFNB49). We generated a knockin mouse that carries a mutation orthologous to the TRIC coding mutation linked to DFNB49 hearing loss in humans. Tricellulin was absent from the tricellular junctions in the inner ear epithelia of the mutant animals, which developed rapidly progressing hearing loss accompanied by loss of mechanosensory cochlear hair cells, while the endocochlear potential and paracellular permeability of a biotin-based tracer in the stria vascularis were unaltered. Freeze-fracture electron microscopy revealed disruption of the strands of intramembrane particles connecting bicellular and tricellular junctions in the inner ear epithelia of tricellulin-deficient mice. These ultrastructural changes may selectively affect the paracellular permeability of ions or small molecules, resulting in a toxic microenvironment for cochlear hair cells. Consistent with this hypothesis, hair cell loss was rescued in tricellulin-deficient mice when generation of normal endolymph was inhibited by a concomitant deletion of the transcription factor, Pou3f4. Finally, comprehensive phenotypic screening showed a broader pathological phenotype in the mutant mice, which highlights the non-redundant roles played by tricellulin. PMID:23979167

  8. [Degradation of oxytetracycline with ozonation in acetic acid solvent].

    PubMed

    Li, Shi-Yin; Li, Xiao-Rong; Zhu, Yi-Ping; Zhu, Jiang-Peng; Wang, Guo-Xiang

    2012-12-01

    Use acetic acid as the media of ozone degradation of oxytetracycline (OTC), and effects of the initial dosing ratio of ozone/OTC, ozone flow, free radical scavenger, metal ions on the removal rate of OTC were investigated respectively. The results showed that acetic acid had a high ozone stability and solubility. OTC had a high removal rate and degradation rate in acetic acid solution. With the increase of OTC dosage, the removal rate of OTC decreased in acetic acid. Removal rate of OTC was increased distinctly when ozone flow increased properly. It was also observed that free radical scavenger had a significantly negative effect on OTC ozonation degradation in acetic acid. Furthermore the main reactions of OTC ozone oxidation were direct oxidation and indirect oxidation in acetic acid. When Fe3+ and Co2+ were existent in acetic acid, the degradation of OTC was inhibited significantly. PMID:23379161

  9. Acetic acid removal from corn stover hydrolysate using ethyl acetate and the impact on Saccharomyces cerevisiae bioethanol fermentation.

    PubMed

    Aghazadeh, Mahdieh; Ladisch, Michael R; Engelberth, Abigail S

    2016-07-01

    Acetic acid is introduced into cellulose conversion processes as a consequence of composition of lignocellulose feedstocks, causing significant inhibition of adapted, genetically modified and wild-type S. cerevisiae in bioethanol fermentation. While adaptation or modification of yeast may reduce inhibition, the most effective approach is to remove the acetic acid prior to fermentation. This work addresses liquid-liquid extraction of acetic acid from biomass hydrolysate through a pathway that mitigates acetic acid inhibition while avoiding the negative effects of the extractant, which itself may exhibit inhibition. Candidate solvents were selected using simulation results from Aspen Plus™, based on their ability to extract acetic acid which was confirmed by experimentation. All solvents showed varying degrees of toxicity toward yeast, but the relative volatility of ethyl acetate enabled its use as simple vacuum evaporation could reduce small concentrations of aqueous ethyl acetate to minimally inhibitory levels. The toxicity threshold of ethyl acetate, in the presence of acetic acid, was found to be 10 g L(-1) . The fermentation was enhanced by extracting 90% of the acetic acid using ethyl acetate, followed by vacuum evaporation to remove 88% removal of residual ethyl acetate along with 10% of the broth. NRRL Y-1546 yeast was used to demonstrate a 13% increase in concentration, 14% in ethanol specific production rate, and 11% ethanol yield. This study demonstrated that extraction of acetic acid with ethyl acetate followed by evaporative removal of ethyl acetate from the raffinate phase has potential to significantly enhance ethanol fermentation in a corn stover bioethanol facility. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:929-937, 2016. PMID:27090191

  10. Trapping social wasps (Hymenoptera: Vespidae) in nurseries with acetic acid and isobutanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    European hornet (Vespa crabro L.) damages bark of nursery trees, and several vespids sting nursery personnel when disturbed. We tested acetic acid and isobutanol lures in traps for V. crabro spring queens, to determine the seasonality of vespid captures, and compare the efficacy of patterns of trap...

  11. Ammonium Acetate and Ammonium Bicarbonate in Traps for Anastrepha Fruit Flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit flies in the genus Anastrepha, especially the reproductive age females, are attracted to protein baits. Synthetic lures based on the principal components of protein degradation, especially ammonia along with acetic acid, were tested against three of the most economically important Anastrepha s...

  12. MANAGING TIGHT BINDING RECEPTORS FOR NEW SPEARATIONS TECHNOLOGIES

    SciTech Connect

    DARYLE H BUSCH RICHARD S GIVENS

    2004-12-10

    Much of the earth's pollution involves compounds of the metallic elements, including actinides, strontium, cesium, technetium, and RCRA metals. Metal ions bind to molecules called ligands, which are the molecular tools that can manipulate the metal ions under most conditions. This DOE-EMSP sponsored program strives (1) to provide the foundations for using the most powerful ligands in transformational separations technologies and (2) to produce seminal examples of their applications to separations appropriate to the DOE EM mission. These ultra tight-binding ligands can capture metal ions in the most competitive of circumstances (from mineralized sites, lesser ligands, and even extremely dilute solutions), but they react so slowly that they are useless in traditional separations methodologies. Two attacks on this problem are underway. The first accommodates to the challenging molecular lethargy by developing a seminal slow separations methodology termed the soil poultice. The second designs ligands that are only tight-binding while wrapped around the targeted metal ion, but can be put in place by switch-binding and removed by switch-release. We envision a kind of molecular switching process to accelerate the union between metal ion and tight-binding ligand. Molecular switching processes are suggested for overcoming the slow natural equilibration rate with which ultra tight-binding ligands combine with metal ions. Ligands that bind relatively weakly combine with metal ions rapidly, so the trick is to convert a ligand from a weak, rapidly binding species to a powerful, slow releasing ligand--during the binding of the ligand to the metal ion. Such switch-binding ligands must react with themselves, and the reaction must take place under the influence of the metal ion. For example, our generation 1 ligands showed that a well-designed linear ligand with ends that readily combine, forms a cyclic molecule when it wraps around a metal ion. Our generation 2 ligands are even

  13. Genotoxic effects of erioflorin acetate and erioflorin methacrylate: Sesquiterpene lactones isolated from Podanthus ovatifolius Lag. (Compositae)

    SciTech Connect

    Cea, G.; Alarcon, M.; Weigert, G.; Sepulveda, R. )

    1990-01-01

    Three major sesquiterpene lactones: eriflorin methacrylate (EM), erioflorin acetate (EA), and ovatifolin acetate (OA) have been isolated from neutral extracts of Podanthus ovatifolius, and all of them have been shown to exhibit antineoplastic properties as tested in standard KB human epidermoid carcinoma of the nasopharynx assay procedures. In the present study the authors report in vivo induction of micronuclei in bone-marrow mice polychromatic erythrocytes (MPCE) by EM, and EA. Chemicals can be screened for chromosome breaking ability by measuring the frequency of erythrocytes with micronuclei derived from acentric chromosomal fragments or lagging chromosomes. This assay has also been described for genotoxicity studies in several mammalian tissues other than polychromatic erythrocytes.

  14. Metabolic acetate therapy improves phenotype in the tremor rat model of Canavan disease

    PubMed Central

    Arun, Peethambaran; Madhavarao, Chikkathur N.; Moffett, John R.; Hamilton, Kristen; Grunberg, Neil E.; Ariyannur, Prasanth S.; Gahl, William A.; Anikster, Yair; Mog, Steven; Hallows, William C.; Denu, John M.

    2010-01-01

    Genetic mutations that severely diminish the activity of aspartoacylase (ASPA) result in the fatal brain dysmyelinating disorder, Canavan disease. There is no effective treatment. ASPA produces free acetate from the concentrated brain metabolite, N-acetylaspartate (NAA). Because acetyl coenzyme A is a key building block for lipid synthesis, we postulated that the inability to catabolize NAA leads to a brain acetate deficiency during a critical period of CNS development, impairing myelination and possibly other aspects of brain development. We tested the hypothesis that acetate supplementation during postnatal myelination would ameliorate the severe phenotype associated with ASPA deficiency using the tremor rat model of Canavan disease. Glyceryltriacetate (GTA) was administered orally to tremor rats starting 7 days after birth, and was continued in food and water after weaning. Motor function, myelin lipids, and brain vacuolation were analyzed in GTA-treated and untreated tremor rats. Significant improvements were observed in motor performance and myelin galactocerebroside content in tremor rats treated with GTA. Further, brain vacuolation was modestly reduced, and these reductions were positively correlated with improved motor performance. We also examined the expression of the acetyl coenzyme A synthesizing enzyme acetyl coenzyme A synthase 1 and found upregulation of expression in tremor rats, with a return to near normal expression levels in GTA-treated tremor rats. These results confirm the critical role played by NAA-derived acetate in brain myelination and development, and demonstrate the potential usefulness of acetate therapy for the treatment of Canavan disease. PMID:20464498

  15. Antihyperglycemic effect of Hypericum perforatum ethyl acetate extract on streptozotocin-induced diabetic rats

    PubMed Central

    Arokiyaraj, S; Balamurugan, R; Augustian, P

    2011-01-01

    Objective To evaluate the antihyperglycemic activity of ethyl acetate extract of Hypericum perforatum (H. perforatum) in streptozotocin (STZ)-induced diabetic rats. Methods Acute toxicity and oral glucose tolerance test were performed in normal rats. Male albino rats were rendered diabetic by STZ (40 mg/kg, intraperitoneally). H. perforatum ethyl acetate extract was orally administered to diabetic rats at 50, 100 and 200 mg/kg doses for 15 days to determine the antihyperglycemic activity. Biochemical parameters were determined at the end of the treatment. Results H. perforatum ethyl acetate extract showed dose dependant fall in fasting blood glucose (FBG). After 30 min of extract administration, FBG was reduced significantly when compared with normal rats. H. perforatum ethyl acetate extract produced significant reduction in plasma glucose level, serum total cholesterol, triglycerides, glucose-6-phosphatase levels. Tissue glycogen content, HDL-cholesterol, glucose-6-phosphate dehydrogenase were significantly increased compared with diabetic control. No death or lethal effect was observed in the toxic study. Conclusions The results demonstrate that H. perforatum ethyl acetate extract possesses potent antihyperglycemic activity in STZ induced diabetic rats. PMID:23569798

  16. A stability-indicating HPLC method for medroxyprogesterone acetate in bulk drug and injection formulation.

    PubMed

    Burana-Osot, Jankana; Ungboriboonpisal, Sooksri; Sriphong, Lawan

    2006-03-18

    A stability-indicating HPLC assay method has been developed and validated for medroxyprogesterone acetate (MPA) in bulk drug and injectable suspension. An isocratic RP-HPLC was achieved on a Hichrom C(18) column (150 mm x 4.6mm i.d., 5 microm) utilizing a mobile phase of methanol 0.020 M acetate buffer pH 5 (65:35, v/v) and a photodiode array detector at 245 nm. The stress testing of MPA was carried out under acidic and alkaline hydrolysis, and oxidation conditions. MPA was well resolved from its degradation products, a main related substance (megestrol acetate) and two preservatives (methyl paraben and propyl paraben) with the resolution >or=2. The proposed method was validated for selectivity, linearity, accuracy, precision and solution stability. The method was found to be suitable for the quality control of MPA in bulk drug and injections as well as the stability-indicating studies. PMID:16242876

  17. Pyruvate Formate-Lyase Enables Efficient Growth of Escherichia coli on Acetate and Formate.

    PubMed

    Zelcbuch, Lior; Lindner, Steffen N; Zegman, Yonatan; Vainberg Slutskin, Ilya; Antonovsky, Niv; Gleizer, Shmuel; Milo, Ron; Bar-Even, Arren

    2016-05-01

    Pyruvate formate-lyase (PFL) is a ubiquitous enzyme that supports increased ATP yield during sugar fermentation. While the PFL reaction is known to be reversible in vitro, the ability of PFL to support microbial growth by condensing acetyl-CoA and formate in vivo has never been directly tested. Here, we employ Escherichia coli mutant strains that cannot assimilate acetate via the glyoxylate shunt and use carbon labeling experiments to unequivocally demonstrate PFL-dependent co-assimilation of acetate and formate. Moreover, PFL-dependent growth is faster than growth on acetate using the glyoxylate shunt. Hence, growth via the reverse activity of PFL could have substantial ecological and biotechnological significance. PMID:27093333

  18. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues

    SciTech Connect

    Reinecke, D. )

    1989-04-01

    Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O{sub 2}, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with {sup 14}C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA.

  19. Diagenesis and porosity evolution of tight sand reservoirs in Carboniferous Benxi Formation, Southeast Ordos Basin

    NASA Astrophysics Data System (ADS)

    Hu, Peng; Yu, Xinghe; Shan, Xin; Su, Dongxu; Wang, Jiao; Li, Yalong; Shi, Xin; Xu, Liqiang

    2016-04-01

    The Ordos Basin, situated in west-central China, is one of the oldest and most important fossil-fuel energy base, which contains large reserves of coal, oil and natural gas. The Upper Palaeozoic strata are widely distributed with rich gas-bearing and large natural gas resources, whose potential is tremendous. Recent years have witnessed a great tight gas exploration improvement of the Upper Paleozoic in Southeastern Ordos basin. The Carboniferous Benxi Formation, mainly buried more than 2,500m, is the key target strata for hydrocarbon exploration, which was deposited in a barrier island and tidal flat environment. The sandy bars and flats are the favorable sedimentary microfacies. With an integrated approach of thin-section petrophysics, constant velocity mercury injection test, scanning electron microscopy and X-ray diffractometry, diagenesis and porosity evolution of tight sand reservoirs of Benxi Formation were analyzed in detail. The result shows that the main lithology of sandstone in this area is dominated by moderately to well sorted quartz sandstone. The average porosity and permeability is 4.72% and 1.22mD. The reservoirs of Benxi Formation holds a variety of pore types and the pore throats, with obvious heterogeneity and poor connection. Based on the capillary pressure curve morphological characteristics and parameters, combined with thin section and phycical property data, the reservoir pore structure of Benxi Formation can be divided into 4 types, including mid pore mid throat type(I), mid pore fine throat type(II), small pore fine throat type(III) and micro pro micro throat type(Ⅳ). The reservoirs primarily fall in B-subsate of middle diagenesis and late diagenesis, which mainly undergo compaction, cmentation, dissolution and fracturing process. Employing the empirical formula of different sorting for unconsolideated sandstone porosity, the initial sandstone porosity is 38.32% on average. Quantitative evaluation of the increase and decrease of

  20. Temperature dependence of ion transport in dilute tetrabutylammonium triflate-acetate solutions and self-diffusion in pure acetate liquids.

    PubMed

    Bopege, Dharshani N; Petrowsky, Matt; Fleshman, Allison M; Frech, Roger; Johnson, Matthew B

    2012-01-12

    Conductivities and static dielectric constants for 0.0055 M tetrabutylammonium trifluoromethanesulfonate in n-butyl acetate, n-pentyl acetate, n-hexyl acetate, n-octyl acetate, and n-decyl acetate have been collected over the temperature range of 0-80 °C. Self-diffusion coefficients and static dielectric constants of pure acetates were obtained over the same temperature range. Both temperature-dependent diffusion coefficients and ionic conductivities of these pure acetates and dilute acetate solutions can be accurately described by the compensated Arrhenius formalism. Activation energies were calculated from compensated Arrhenius plots for both conductivity and diffusion data. Activation energies are higher for conductivity data of 0.0055 M TbaTf-acetates compared to diffusion data of pure acetates. The plot of the exponential prefactor versus the dielectric constant yields a single master curve for both conductivity and diffusion data. These data support the argument that mass and charge transport are thermally activated processes in the acetates, as previously observed in alcohol-based electrolytes. PMID:22145961

  1. Effects of Etlingera elatior extracts on lead acetate-induced testicular damage: A morphological and biochemical study

    PubMed Central

    HAW, KHOR YEN; CHAKRAVARTHI, SRIKUMAR; HALEAGRAHARA, NAGARAJA; RAO, MALLIKARJUNA

    2012-01-01

    Lead causes damage to the whole body by inducing oxidative stress. This includes the testis, in which spermatogenesis is affected. Etlingera elatior, a consumable plant that is being extensively studied for its high anti-oxidant properties, was tested against the effect of lead acetate in experimental rats. Rats were divided into groups consisting of a control, lead acetate only, Etlingera elatior treatment only, concurrent treatment of lead acetate and Etlingera elatior, post-treatment of lead acetate followed by Etlingera elatior and preventive group of Etlingera elatior followed by lead acetate. The substances were administered for 14 days and the effects were measured by protein carbonyl content (PCC), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity in the testis, as well as the testosterone level in the serum. Histological changes in the testis were also observed. Results showed that Etlingera elatior induced a significant reduction in the testis PCC activity, while at the same time it significantly increased the activities of SOD and GPx in the testis, and the testosterone level in the serum. Etlingera elatior also improved the histology of the testis when compared to the lead acetate-treated group. On the whole, Etlingera elatior is effective against oxidative damage caused by lead acetate in the testis. PMID:22969852

  2. GEOLOGIC ASPECTS OF TIGHT GAS RESERVOIRS IN THE ROCKY MOUNTAIN REGION.

    USGS Publications Warehouse

    Spencer, Charles W.

    1985-01-01

    The authors describe some geologic characteristics of tight gas reservoirs in the Rocky Mountain region. These reservoirs usually have an in-situ permeability to gas of 0. 1 md or less and can be classified into four general geologic and engineering categories: (1) marginal marine blanket, (2) lenticular, (3) chalk, and (4) marine blanket shallow. Microscopic study of pore/permeability relationships indicates the existence of two varieties of tight reservoirs. One variety is tight because of the fine grain size of the rock. The second variety is tight because the rock is relatively tightly cemented and the pores are poorly connected by small pore throats and capillaries.

  3. Chemoselectivities in acetalization, thioacetalization, oxathioacetalization and azathioacetalization.

    PubMed

    Roy, Ram Kinkar; Bagaria, Priyanka; Naik, Sarala; Kavala, Veerababurao; Patel, Bhisma K

    2006-02-16

    In the present article (experimental as well theoretical) the relative yields of cyclic (O,O), (S,S), (S,O), and (S,N) acetals, formed from p-(NO2)C6H4CHO and p-(OH)C6H4CHO, are compared. Atomic charges, global electrophilicity descriptor (w) [as proposed by Parr et al., J. Am. Chem. Soc. 1999, 121, 1922] and hard-soft acid-base concept of Pearson (J. Am. Chem. Soc. 1963, 85, 3533) are used to explain the experimental observations. Although the w values can explain the yields, charge and local softness values of the interacting sites explain the plausible reaction mechanism. The bisnucleophiles chosen for acetalization are CH2(OH)-CH2(OH) (glycol), CH2(SH)-CH2(SH) (dithiol), CH2(OH)-CH2(SH) (oxathiol) and CH2(SH)-CH2(NH2) (azathiol). For p-(NO2)C6H4CHO, the experimental yield of cyclic acetals were found to follow the trend as (S,N) > (S,O) > (O,O) > (S,S), which is also supported by theoretical explanation based on the w values and applying the concept of hard-hard (i.e., charge-controlled) and soft-soft (i.e., orbital-controlled) interaction between the interacting sites of the substrates (i.e., aldehydes) and the reactants (bisnucleophiles). Similarly, for p-(OH)C6H4CHO the relative yields of cyclic acetals follow the trend (S,N) approximately (S,S) > (S,O) > (O,O). It is argued that the attack on C(CHO) (i.e., C-atom of the CHO group) in p-(NO2)C6H4CHO by O(OH) (i.e., O-atom of OH group) or N(NH2) (i.e., N-atom of NH2 group) is mainly charge-controlled but the attack on C(CHO) in p-(OH)C6H4CHO) by S(SH) (i.e., S-atom of SH group) is orbital-controlled. PMID:16466254

  4. ADVANCED FRACTURING TECHNOLOGY FOR TIGHT GAS: AN EAST TEXAS FIELD DEMONSTRATION

    SciTech Connect

    Mukul M. Sharma

    2005-03-01

    The primary objective of this research was to improve completion and fracturing practices in gas reservoirs in marginal plays in the continental United States. The Bossier Play in East Texas, a very active tight gas play, was chosen as the site to develop and test the new strategies for completion and fracturing. Figure 1 provides a general location map for the Dowdy Ranch Field, where the wells involved in this study are located. The Bossier and other tight gas formations in the continental Unites States are marginal plays in that they become uneconomical at gas prices below $2.00 MCF. It was, therefore, imperative that completion and fracturing practices be optimized so that these gas wells remain economically attractive. The economic viability of this play is strongly dependent on the cost and effectiveness of the hydraulic fracturing used in its well completions. Water-fracs consisting of proppant pumped with un-gelled fluid is the type of stimulation used in many low permeability reservoirs in East Texas and throughout the United States. The use of low viscosity Newtonian fluids allows the creation of long narrow fractures in the reservoir, without the excessive height growth that is often seen with cross-linked fluids. These low viscosity fluids have poor proppant transport properties. Pressure transient tests run on several wells that have been water-fractured indicate a long effective fracture length with very low fracture conductivity even when large amounts of proppant are placed in the formation. A modification to the water-frac stimulation design was needed to transport proppant farther out into the fracture. This requires suspending the proppant until the fracture closes without generating excessive fracture height. A review of fracture diagnostic data collected from various wells in different areas (for conventional gel and water-fracs) suggests that effective propped lengths for the fracture treatments are sometimes significantly shorter than those

  5. Diagenesis and reservoir quality of the Lower Cretaceous Quantou Formation tight sandstones in the southern Songliao Basin, China

    NASA Astrophysics Data System (ADS)

    Xi, Kelai; Cao, Yingchang; Jahren, Jens; Zhu, Rukai; Bjørlykke, Knut; Haile, Beyene Girma; Zheng, Lijing; Hellevang, Helge

    2015-12-01

    The Lower Cretaceous Quantou Formation in the southern Songliao Basin is the typical tight oil sandstone in China. For effective exploration, appraisal and production from such a tight oil sandstone, the diagenesis and reservoir quality must be thoroughly studied first. The tight oil sandstone has been examined by a variety of methods, including core and thin section observation, XRD, SEM, CL, fluorescence, electron probing analysis, fluid inclusion and isotope testing and quantitative determination of reservoir properties. The sandstones are mostly lithic arkoses and feldspathic litharenites with fine to medium grain size and moderate to good sorting. The sandstones are dominated by feldspar, quartz, and volcanic rock fragments showing various stages of disintegration. The reservoir properties are quite poor, with low porosity (average 8.54%) and permeability (average 0.493 mD), small pore-throat radius (average 0.206 μm) and high displacement pressure (mostly higher than 1 MPa). The tight sandstone reservoirs have undergone significant diagenetic alterations such as compaction, feldspar dissolution, quartz cementation, carbonate cementation (mainly ferrocalcite and ankerite) and clay mineral alteration. As to the onset time, the oil emplacement was prior to the carbonate cementation but posterior to the quartz cementation and feldspar dissolution. The smectite to illite reaction and pressure solution at stylolites provide a most important silica sources for quartz cementation. Carbonate cements increase towards interbedded mudstones. Mechanical compaction has played a more important role than cementation in destroying the reservoir quality of the K1q4 sandstone reservoirs. Mixed-layer illite/smectite and illite reduced the porosity and permeability significantly, while chlorite preserved the porosity and permeability since it tends to be oil wet so that later carbonate cementation can be inhibited to some extent. It is likely that the oil emplacement occurred

  6. DISCOVERY OF A TIGHT CORRELATION FOR GAMMA-RAY BURST AFTERGLOWS WITH 'CANONICAL' LIGHT CURVES

    SciTech Connect

    Dainotti, Maria Giovanna; Ostrowski, Michal; Willingale, Richard; Capozziello, Salvatore; Cardone, Vincenzo Fabrizio E-mail: mio@oa.uj.edu.p E-mail: capozziello@na.infn.i

    2010-10-20

    Gamma-ray bursts (GRBs) observed up to redshifts z>8 are fascinating objects to study due to their still unexplained relativistic outburst mechanisms and their possible use to test cosmological models. Our analysis of 77 GRB afterglows with known redshifts revealed a physical subsample of long GRBs with the canonical plateau breaking to power-law light curves with a significant luminosity L*{sub X}-break time T*{sub a} correlation in the GRB rest frame. This subsample forms approximately the upper envelope of the studied distribution. We have also found a similar relation for a small sample of GRB afterglows that belong to the intermediate class between the short and the long ones. It proves that within the full sample of afterglows there exist physical subclasses revealed here by tight correlations of their afterglow properties. The afterglows with regular ('canonical') light curves obey not only the mentioned tight physical scaling, but-for a given T*{sub a}-the more regular progenitor explosions lead to preferentially brighter afterglows.

  7. Real evaporative cooling efficiency of one-layer tight-fitting sportswear in a hot environment.

    PubMed

    Wang, F; Annaheim, S; Morrissey, M; Rossi, R M

    2014-06-01

    Real evaporative cooling efficiency, the ratio of real evaporative heat loss to evaporative cooling potential, is an important parameter to characterize the real cooling benefit for the human body. Previous studies on protective clothing showed that the cooling efficiency decreases with increasing distance between the evaporation locations and the human skin. However, it is still unclear how evaporative cooling efficiency decreases as the moisture is transported from the skin to the clothing layer. In this study, we performed experiments with a sweating torso manikin to mimic three different phases of moisture absorption in one-layer tight-fitting sportswear. Clothing materials Coolmax(®) (CM; INVISTA, Wichita, Kansas, USA; 100%, profiled cross-section polyester fiber), merino wool (MW; 100%), sports wool (SW; 50% wool, 50% polyester), and cotton (CO; 100%) were selected for the study. The results demonstrated that, for the sportswear materials tested, the real evaporative cooling efficiency linearly decreases with the increasing ratio of moisture being transported away from skin surface to clothing layer (adjusted R(2) >0.97). In addition, clothing fabric thickness has a negative effect on the real evaporative cooling efficiency. Clothing CM and SW showed a good ability in maintaining evaporative cooling efficiency. In contrast, clothing MW made from thicker fabric had the worst performance in maintaining evaporative cooling efficiency. It is thus suggested that thin fabric materials such as CM and SW should be used to manufacture one-layer tight-fitting sportswear. PMID:24033668

  8. An extremely low profile, compact, and broadband tightly coupled patch array

    NASA Astrophysics Data System (ADS)

    Irci, E.; Sertel, K.; Volakis, John L.

    2012-01-01

    A tightly coupled patch array (TCPA) is introduced to realize small-size, extremely low profile planar antennas with broadband performance. Past approaches have used frequency selective surfaces (FSSs) as part of the substrate or ground plane (i.e., in passive mode) for also realizing low-profile antennas. In contrast, the proposed TCPA employs an FSS aperture as the radiating structure (i.e., array antenna). A key aspect of the TCPA is the exploitation of differences in FSSs when operating in radiating and passive modes. Tight element coupling and periodic excitation are the keys for achieving broadband operation. In this paper, a small-size, finite array is designed along with a very thin and compact feeding network. The designed TCPA resonated at 2.07 GHz with 5.6% impedance bandwidth (∣S11∣ < -10 dB), 4.4 dB realized gain (86% efficiency), and 23% gain bandwidth (3 dB drop). Of importance is that the overall aperture dimensions were only λ0/3 × λ0/3 and λ0/42 thick (including feeding network) at the midfrequency of operation. A preliminary TCPA antenna prototype was fabricated and tested. Both simulated and measured data show enhanced bandwidth as compared to the conventional microstrip patch antennas of the same size and thickness. However, as common for such extremely low profile microstrip antennas, the conductivity losses were augmented. Thus, the measured TCPA efficiency (50%) was smaller than computed.

  9. Secondary. cap alpha. -deuterium kinetic isotope effects in solvolyses of ferrocenylmethyl acetate and benzoate in ethanol

    SciTech Connect

    Sutic, D.; Asperger, S.; Borcic, S.

    1982-12-17

    Secondary ..cap alpha..-deuterium kinetic isotope effects (KIE) in solvolyses of ferrocenyldideuteriomethyl acetate and benzoate were determined in 96% (v/v) ethanol, at 25/sup 0/C, as k/sub H//k/sub D/ = 1.24 and 1.26, respectively. The KIEs were also determined in the presence of 0.1 mol dm/sup -3/ lithium perchlorate: the k/sub H//k/ sub D/ values were 1.23 and 1.22 for acetate and benzoate complexes, respectively. The maximum KIE for the C-O bond cleavage of a primary substrate is as large as, or larger than, that of secondary derivatives, which is estimated to be 1.23 per deuterium. The measured KIE of about 12% per D therefore represents a strongly reduced effect relative to its maximum. The solvolyses exhibit ''a special salt effect''. This effect indicates the presence of solvent-separated ion pairs and the return to tight pairs. As the maximum KIE is expected in solvolyses involving transformation of one type of ion pair into another, the strongly reduced ..cap alpha..-D KIE supports the structure involving direct participation of electrons that in the ground state are localized at the iron atom. The alkyl-oxygen cleavage is accompanied by 10-15% acyl-oxygen cleavage.

  10. Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii.

    PubMed

    Lindahl, Lina; Genheden, Samuel; Eriksson, Leif A; Olsson, Lisbeth; Bettiga, Maurizio

    2016-04-01

    Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic-acid-tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations, we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingo-lipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin-treated cells than in control cells. This indicates a higher inflow rate of acetic acid and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress. PMID:26416641

  11. Many-body tight-binding model for aluminum nanoparticles

    SciTech Connect

    Staszewska, Grazyna; Staszewski, Przemyslaw; Schultz, Nathan E.; Truhlar, Donald G.

    2005-01-15

    A new, parametrized many-body tight-binding model is proposed for calculating the potential energy surface for aluminum nanoparticles. The parameters have been fitted to reproduce the energies for a variety of aluminum clusters (Al{sub 2}, Al{sub 3}, Al{sub 4}, Al{sub 7}, Al{sub 13}) calculated recently by the PBE0/MG3 method as well as the experimental face-centered-cubic cohesive energy, lattice constant, and a small set of Al cluster ionization potentials. Several types of parametrization are presented and compared. The mean unsigned error per atom for the best model is less than 0.03 eV.

  12. Universal Sign Control of Coupling in Tight-Binding Lattices.

    PubMed

    Keil, Robert; Poli, Charles; Heinrich, Matthias; Arkinstall, Jake; Weihs, Gregor; Schomerus, Henning; Szameit, Alexander

    2016-05-27

    We present a method of locally inverting the sign of the coupling term in tight-binding systems, by means of inserting a judiciously designed ancillary site and eigenmode matching of the resulting vertex triplet. Our technique can be universally applied to all lattice configurations, as long as the individual sites can be detuned. We experimentally verify this method in laser-written photonic lattices and confirm both the magnitude and the sign of the coupling by interferometric measurements. Based on these findings, we demonstrate how such universal sign-flipped coupling links can be embedded into extended lattice structures to impose a Z_{2}-gauge transformation. This opens a new avenue for investigations on topological effects arising from magnetic fields with aperiodic flux patterns or in disordered systems. PMID:27284657

  13. Multiporosity Flow of Gases in Tight Shale Formations

    NASA Astrophysics Data System (ADS)

    Kuhlman, K. L.; Heath, J. E.; Gardner, P.; Robinson, D. G.

    2014-12-01

    Flow and transport in low-permeability fractured systems is important in both groundwater applications and low-permeability hydrocarbon systems. We have adapted the multirate solute transport model to the flow of single-phase natural tracers in low-permeability hydrocarbon source rocks, termed the multiporosity model. We illustrate the ability of the multiporosity model to generalize double-porosity models, of both the pseudo-steady (e.g., Warren and Root) and transient (Kazemi) interporosity flow types. We use the model to explore both production (pressure and flowrate) and compositional data obtained from tight gas shale formations using a Baeysian uncertainty quantification approach.Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  14. Crude oil prices: Are our oil markets too tight?

    SciTech Connect

    Simmons, M.R.

    1997-02-01

    The answer to the question posed in the title is that tightness in the market will surely prevail through 1997. And as discussed herein, with worldwide demand expected to continue to grow, there will be a strong call on extra oil supply. Meeting those demands, however, will not be straightforward--as many observers wrongly believe--considering the industry`s practice of maintaining crude stocks at ``Just in time`` inventory levels. Further, impact will be felt from the growing rig shortage, particularly for deepwater units, and down-stream capacity limits. While these factors indicate 1997 should be another good year for the service industry, it is difficult to get any kind of consensus view from the oil price market. With most observers` information dominated by the rarely optimistic futures price of crude, as reflected by the NYMEX, the important fact is that oil prices have remained stable for three years and increased steadily through 1996.

  15. Quantifying tight-gas sandstone permeability via critical path analysis

    NASA Astrophysics Data System (ADS)

    Ghanbarian, Behzad; Torres-Verdín, Carlos; Skaggs, Todd H.

    2016-06-01

    Rock permeability has been actively investigated over the past several decades by the geosciences community. However, its accurate estimation still presents significant technical challenges, particularly in spatially complex rocks. In this short communication, we apply critical path analysis (CPA) to estimate permeability in porous rocks from measured mercury intrusion porosimetry and electrical conductivity data. Theoretical estimations of various CPA-based models are then compared to experimental measurements using eighteen tight-gas sandstones. Except for two of the samples, we find permeability estimations performed with the Skaggs model (assuming pore diameter independent of its length) more accurate than other models, within a factor of two of the measured permeabilities. We discuss some plausible sources of the uncertainties.

  16. Tight-binding approach to penta-graphene

    PubMed Central

    Stauber, T.; Beltrán, J. I.; Schliemann, J.

    2016-01-01

    We introduce an effective tight-binding model to discuss penta-graphene and present an analytical solution. This model only involves the π-orbitals of the sp2-hybridized carbon atoms and reproduces the two highest valence bands. By introducing energy-dependent hopping elements, originating from the elimination of the sp3-hybridized carbon atoms, also the two lowest conduction bands can be well approximated - but only after the inclusion of a Hubbard onsite interaction as well as of assisted hopping terms. The eigenfunctions can be approximated analytically for the effective model without energy-dependent hopping elements and the optical absorption is discussed. We find large isotropic absorption ranging from 7.5% up to 24% for transitions at the Γ-point. PMID:26940279

  17. Tight-binding lattices with an oscillating imaginary gauge field

    NASA Astrophysics Data System (ADS)

    Longhi, Stefano

    2016-08-01

    We consider non-Hermitian dynamics of a quantum particle hopping on a one-dimensional tight-binding lattice made of N sites with asymmetric hopping rates induced by a time-periodic oscillating imaginary gauge field. A deeply different behavior is found depending on the lattice topology. While in a linear chain (open boundary conditions) an oscillating field can lead to a complex quasienergy spectrum via a multiple parametric resonance; in a ring topology (Born-von Karman periodic boundary conditions) an entirely real quasienergy spectrum can be found and the dynamics is pseudo-Hermitian. In the large-N limit, parametric instability and pseudo-Hermitian dynamics in the two different lattice topologies are physically explained on the basis of a simple picture of wave-packet propagation.

  18. Detection of Tight Junction Barrier Function In Vivo by Biotin

    PubMed Central

    Ding, Lei; Zhang, Yuguo; Tatum, Rodney; Chen, Yan-Hua

    2011-01-01

    Tight junctions (TJs) are the most apical component of the junctional complexes in mammalian epithelial cells and form selective paracellular barriers restricting the passage of solutes and ions across the epithelial sheets. Claudins, a TJ integral membrane protein family, play a critical role in regulating paracellular barrier permeability. In the in vitro cell culture system, transepithelial electrical resistance (TER) measurement and the flux of radioisotope or fluorescent labeled molecules with different sizes have been widely used to determine the TJ barrier function. In the in vivo system, the tracer molecule Sulfo-NHS-Biotin was initially used in Xenopus embryos system and subsequently was successfully applied to a number of animal tissues in situ and in different organisms under the experimental conditions to examine the functional integrity of TJs by several laboratories. In this chapter, we will describe the detailed procedures of applying biotin as a paracellular tracer molecule to different in vivo systems to assay TJ barrier function. PMID:21717351

  19. Universal Sign Control of Coupling in Tight-Binding Lattices

    NASA Astrophysics Data System (ADS)

    Keil, Robert; Poli, Charles; Heinrich, Matthias; Arkinstall, Jake; Weihs, Gregor; Schomerus, Henning; Szameit, Alexander

    2016-05-01

    We present a method of locally inverting the sign of the coupling term in tight-binding systems, by means of inserting a judiciously designed ancillary site and eigenmode matching of the resulting vertex triplet. Our technique can be universally applied to all lattice configurations, as long as the individual sites can be detuned. We experimentally verify this method in laser-written photonic lattices and confirm both the magnitude and the sign of the coupling by interferometric measurements. Based on these findings, we demonstrate how such universal sign-flipped coupling links can be embedded into extended lattice structures to impose a Z2-gauge transformation. This opens a new avenue for investigations on topological effects arising from magnetic fields with aperiodic flux patterns or in disordered systems.

  20. Methods and apparatus for measuring the tightness of enclosures

    DOEpatents

    Modera, Mark P.; Sherman, Max H.

    1987-01-13

    Disclosed are methods and apparatus for measuring tightness of an enclosure such as a building by utilizing alternating pressurization techniques. One method comprises providing apparatus capable of causing an internal volume change for the enclosure, the apparatus including a means for determining the instantaneous volume change, and a means for determining the instantaneous pressure within the enclosure. The apparatus is operated within the enclosure to change the volume thereof, and at least one of the frequency and the displacement is adjusted to achieve a root mean square pressure in the enclosure approximately equal to a reference pressure. At that pressure, the leakage of the enclosure is determined from the instantaneous displacement and instantaneous pressure values.

  1. Qutrit Magic State Distillation Tight in Some Directions

    NASA Astrophysics Data System (ADS)

    Dawkins, Hillary; Howard, Mark

    2015-07-01

    Magic state distillation is a crucial component in the leading approaches to implementing universal fault-tolerant quantum computation, with existing protocols for both qubit and higher dimensional systems. Early work focused on determining the region of distillable states for qubit protocols; yet comparatively little is known about which states can be distilled and with what distillable region for d >2 . Here we focus on d =3 and present new four-qutrit distillation schemes that improve upon the known distillable region, and achieve distillation tight to the boundary of undistillable states for some classes of state. As a consequence of recent results, this implies that there is a family of quantum states that enable universality if and only if they exhibit contextuality with respect to stabilizer measurements. We also identify a new routine whose fixed point is a magic state with maximal sum negativity; i.e., it is maximally nonstablizer in a specific sense.

  2. Tight-binding approach to penta-graphene

    NASA Astrophysics Data System (ADS)

    Stauber, T.; Beltrán, J. I.; Schliemann, J.

    2016-03-01

    We introduce an effective tight-binding model to discuss penta-graphene and present an analytical solution. This model only involves the π-orbitals of the sp2-hybridized carbon atoms and reproduces the two highest valence bands. By introducing energy-dependent hopping elements, originating from the elimination of the sp3-hybridized carbon atoms, also the two lowest conduction bands can be well approximated - but only after the inclusion of a Hubbard onsite interaction as well as of assisted hopping terms. The eigenfunctions can be approximated analytically for the effective model without energy-dependent hopping elements and the optical absorption is discussed. We find large isotropic absorption ranging from 7.5% up to 24% for transitions at the Γ-point.

  3. Methods and apparatus for measuring the tightness of enclosures

    DOEpatents

    Modera, M.P.; Sherman, M.H.

    1987-01-13

    Disclosed are methods and apparatus for measuring tightness of an enclosure such as a building by utilizing alternating pressurization techniques. One method comprises providing apparatus capable of causing an internal volume change for the enclosure, the apparatus including a means for determining the instantaneous volume change, and a means for determining the instantaneous pressure within the enclosure. The apparatus is operated within the enclosure to change the volume thereof, and at least one of the frequency and the displacement is adjusted to achieve a root mean square pressure in the enclosure approximately equal to a reference pressure. At that pressure, the leakage of the enclosure is determined from the instantaneous displacement and instantaneous pressure values. 3 figs.

  4. Remarks on the tight-binding model of graphene

    NASA Astrophysics Data System (ADS)

    Bena, Cristina; Montambaux, Gilles

    2009-09-01

    We address a simple but fundamental issue arising in the study of graphene, as well as of other systems that have a crystalline structure with more than one atom per unit cell. For these systems, the choice of the tight-binding basis is not unique. For monolayer graphene two bases are widely used in the literature. While the expectation values of operators describing physical quantities should be independent of basis, the form of the operators may depend on the basis, especially in the presence of disorder or of an applied magnetic field. Using an inappropriate form of certain operators may lead to erroneous physical predictions. We discuss the two bases used to describe monolayer graphene, as well as the form of the most commonly used operators in the two bases. We repeat our analysis for the case of bilayer graphene.

  5. Quantum Physics Inspired Optical Effects in Tight-Binding Lattices

    NASA Astrophysics Data System (ADS)

    Thompson, Clinton; Vemuri, Gautam

    We theoretically investigated the propagation of light inside an array of single-mode evanescently coupled waveguides that can be described by the tight-binding Hamiltonian. We show that directed photonic transport can be achieved with phase-displaced inputs. In addition, the form of a parity-symmetric waveguide-dependent coupling constant can tune the dynamics of the photon's wavepacket. Lastly, we examine the statistical aspects of the output light for different input fields when disorder is present in the waveguide array. We find that the light will undergo Anderson localization independent of the type of field and that the intensity fluctuations of the output light will increase with disorder at the initial waveguide.

  6. Elemental and tight monogamy relations in nonsignaling theories

    NASA Astrophysics Data System (ADS)

    Augusiak, R.; Demianowicz, M.; Pawłowski, M.; Tura, J.; Acín, A.

    2014-11-01

    Physical principles constrain the way nonlocal correlations can be distributed among distant parties. These constraints are usually expressed by monogamy relations that bound the amount of Bell inequality violation observed among a set of parties by the violation observed by a different set of parties. We prove here that much stronger monogamy relations are possible for nonsignaling correlations by showing how nonlocal correlations among a set of parties limit any form of correlations, not necessarily nonlocal, shared among other parties. In particular, we provide tight bounds between the violation of a family of Bell inequalities among an arbitrary number of parties and the knowledge an external observer can gain about outcomes of any single measurement performed by the parties. Finally, we show how the obtained monogamy relations offer an improvement over the existing protocols for device-independent quantum key distribution and randomness amplification.

  7. Bacteria-tight sealing of exposed dog pulps.

    PubMed

    Wijnbergen-Buijen van Weelderen, M; van Mullem, P J

    1984-05-01

    Penetration of bacteria past filling materials can interfere with the vitality of exposed pulps. In the present study, seventy-three dog's teeth were filled--after exposure--with Cavit -W and then sealed either with a chemically or a UV polymerizing bonding. After 14 days a failure rate of 28% was demonstrated using the chemically polymerizing Concise and of 4.5% using the UV polymerizing Uvio -Bond. After 42 days the latter bonding revealed a success rate of 100%. To achieve a bacteria-tight seal of deep cavities for middle long term animal experimentation, Uvio -Bond can be used--after etching--to cover the filling material and the surrounding enamel. PMID:6234386

  8. Tight-binding study of bilayer graphene Josephson junctions

    NASA Astrophysics Data System (ADS)

    Muñoz, W. A.; Covaci, L.; Peeters, F. M.

    2012-11-01

    Using highly efficient simulations of the tight-binding Bogoliubov-de-Gennes model, we solved self-consistently for the pair correlation and the Josephson current in a superconducting-bilayer graphene-superconducting Josephson junction. Different doping levels for the non-superconducting link are considered in the short- and long-junction regimes. Self-consistent results for the pair correlation and superconducting current resemble those reported previously for single-layer graphene except at the Dirac point, where remarkable differences in the proximity effect are found, as well as a suppression of the superconducting current in the long-junction regime. Inversion symmetry is broken by considering a potential difference between the layers and we found that the supercurrent can be switched if the junction length is larger than the Fermi length.

  9. Quasi-symmetric designs and equiangular tight frames

    NASA Astrophysics Data System (ADS)

    Fickus, Matthew; Jasper, John; Mixon, Dustin; Peterson, Jesse

    2015-08-01

    An equiangular tight frame (ETF) is an M×N matrix which has orthogonal equal norm rows, equal norm columns, and the inner products of all pairs of columns have the same modulus. ETFs arise in numerous applications, including compressed sensing. They also seem to be rare: despite over a decade of active research by the community, only a few construction methods have been discovered. In this article we introduce a new construction of ETFs which uses a particular set of combinatorial designs called quasi-symmetric designs. For ETFs whose entries are contained in {+1;-1}, called real constant amplitude ETFs (RCAETFs), we see that this construction is reversible, giving new quasi-symmetric designs from the known constructions RCAETFs.

  10. Potential tight gas resources in a frontier province - Jurassic through Tertiary strata beneath the Brooks Range foothills, Arctic Alaska

    USGS Publications Warehouse

    Nelson, Philip H.; Bird, Kenneth J.; Houseknecht, David W.; Potter, Christopher J.; Moore, Thomas E.

    2006-01-01

    Beneath the foothills of the Brooks Range, rocks of the Lower Cretaceous-Tertiary Brookian and Jurassic-Lower Cretaceous Beaufortian megasequences have been deeply buried and exhumed, and now exhibit characteristics of 'tight gas sandstones'. The data recovered from drilling, well tests, and cores exhibit the potential for substantial gas reserves over a large area. These data include recovery of gas from drillstem tests, indications of overpressure from well tests and mud weights, low porosity and permeability in sandstones, and vitrinite reflectance values ranging from 1.0 to 2.0 percent throughout substantial depth intervals.

  11. Contrasting evolutionary histories among tightly linked HLA loci.

    PubMed Central

    Klitz, W; Thomson, G; Baur, M P

    1986-01-01

    Genes comprising the major histocompatibility complex (MHC) play a central role in governing the immune response of vertebrates. A great deal of information has been revealed on the molecular biology and physiology of these loci, but three features-the high polymorphism, tight linkage among the loci, and the nonrandom association of alleles-make the system of particular interest from the perspective of population genetics. Information on the dynamic evolutionary forces that have acted on a locus can be inferred from the number and distribution of alleles that it carries. Ten loci from the HLA region of the human MHC, each sampled from several different populations, have been examined for departures from the expected value of homozygosity under the condition of selective neutrality. The homozygosities of five class I and II loci that code for membrane glycoproteins, HLA-A, -B, -C, -DR, and -DQ, and of glyoxylase I (GLO) were significantly less than the neutrality expectations. This suggests the presence of some form of balancing selection. In spite of being closely linked, in fact, located between the class I and class II histocompatibility loci, the homozygosities of the four class III or complement loci C2, Bf, C4A, and C4B, which are detected by electrophoresis, were indistinguishable from, or exceeded, that expected under neutrality. Although this conforms to the suggestion that, in general, electrophoretic variants are neutral, because of the tight linkage to loci demonstrating a history of selection, it is possible that the mechanism for generating variation in the class III loci may be different from that of the class I and class II loci. PMID:3766540

  12. Immunotoxicity of trenbolone acetate in Japanese quail

    USGS Publications Warehouse

    Quinn, M.J.; McKernan, M.; Lavoie, E.T.; Ottinger, M.A.

    2007-01-01

    Trenbolone acetate is a synthetic androgen that is currently used as a growth promoter in many meat-exporting countries. Despite industry laboratories classifying trenbolone as nonteratogenic, data showed that embryonic exposure to this androgenic chemical altered development of the immune system in Japanese quail. Trenbolone is lipophilic, persistent, and released into the environment in manure used as soil fertilizer. This is the first study to date to assess this chemical's immunotoxic effects in an avian species. A one-time injection of trenbolone into yolks was administered to mimic maternal deposition, and subsequent effects on the development and function of the immune system were determined in chicks and adults. Development of the bursa of Fabricius, an organ responsible for development of the humoral arm of the immune system, was disrupted, as indicated by lower masse, and smaller and fewer follicles at day 1 of hatch. Morphological differences in the bursas persisted in adults, although no differences in either two measures of immune function were observed. Total numbers of circulating leukocytes were reduced and heterophil-lymphocyte ratios were elevated in chicks but not adults. This study shows that trenbolone acetate is teratogenic and immunotoxic in Japanese quail, and provides evidence that the quail immune system may be fairly resilient to embryonic endocrine-disrupting chemical-induced alterations following no further exposure posthatch.

  13. Phytogenic biosynthesis and emission of methyl acetate.

    PubMed

    Jardine, Kolby; Wegener, Frederik; Abrell, Leif; van Haren, Joost; Werner, Christiane

    2014-02-01

    Acetylation of plant metabolites fundamentally changes their volatility, solubility and activity as semiochemicals. Here we present a new technique termed dynamic (13) C-pulse chasing to track the fate of C1-3 carbon atoms of pyruvate into the biosynthesis and emission of methyl acetate (MA) and CO2 . (13) C-labelling of MA and CO2 branch emissions respond within minutes to changes in (13) C-positionally labelled pyruvate solutions fed through the transpiration stream. Strong (13) C-labelling of MA emissions occurred only under pyruvate-2-(13) C and pyruvate-2,3-(13) C feeding, but not pyruvate-1-(13) C feeding. In contrast, strong (13) CO2 emissions were only observed under pyruvate-1-(13) C feeding. These results demonstrate that MA (and other volatile and non-volatile metabolites) derive from the C2,3 atoms of pyruvate while the C1 atom undergoes decarboxylation. The latter is a non-mitochondrial source of CO2 in the light generally not considered in studies of CO2 sources and sinks. Within a tropical rainforest mesocosm, we also observed atmospheric concentrations of MA up to 0.6 ppbv that tracked light and temperature conditions. Moreover, signals partially attributed to MA were observed in ambient air within and above a tropical rainforest in the Amazon. Our study highlights the potential importance of acetyl coenzyme A (CoA) biosynthesis as a source of acetate esters and CO2 to the atmosphere. PMID:23862653

  14. Identification of Indole-3-Acetic Acid in the Basidiomycete Schizophyllum commune 1

    PubMed Central

    Epstein, Ephraim; Miles, Philip G.

    1967-01-01

    Indole-3-acetic acid (IAA) was detected in the ether extracts of culture filtrates of indigotin-producing strains of the basidiomycete Schizophyllum commune. Several solvents, known to give distinctly different RF values for IAA, and 3 location reagents gave identical results with synthetic IAA and IAA found in the extract. Confirmation was obtained by the Avena straight growth test, split pea test, and ultraviolet absorption spectrum. PMID:16656596

  15. Effect of cyproterone acetate on pituitary-adrenocortical function in man.

    PubMed

    van Wayjen, R G; van den Ende, A

    1981-01-01

    Recent literature (1973-1976) suggests suppression of pituitary-adrenal function in patients (eg with pubertas praecox) who are treated with cyproterone acetate in high doses for prolonged periods. Therefore we investigated in our metabolic ward the effects of administration of 200 mg cyproterone acetate per day during 20 days to 4 healthy male volunteers. Baseline plasma cortisol and ACTH levels, repeated diurnal plasma cortisol and ACTH profiles and the results of tetracosactide (Synacthen) stimulation tests and single-dose metyrapone (Metopiron) tests proved to be comparable before, during and after treatment. Moreover, a slight gradual increase in urinary cortisol excretion during the observation period indicated that cyproterone acetate in the given dose during 20 days certainly does not reduce the pituitary-adrenal function of 4 healthy male volunteers. Long-term administration (during 1 to 7 years) of the combination of cyproterone acetate and ethinyloestradiol did not suppress serum levels of cortisol, prolactin, thyroxine and TSH in 18 female patients with hirsutism and/or acne. PMID:6257015

  16. A radioimmunoassay for serum medroxyprogesterone acetate.

    PubMed

    Shrimanker, K; Saxena, B N; Fotherby, K

    1978-04-01

    When injected intramuscularly in a dose of 150 mg, Depo Provera, a microcrystalline suspension of medroxyprogesterone acetate (MPA), will provide a contraceptive effect for at least 3 months. This paper describes a sensitive radioimmunoassay for MPA which has been used in the author's laboratory for the past 2 years. MPA was converted to MPA-3-CMO and the oxime was conjugated with bovine serum albumin (BSA) by the mixed anahydride method. 4 rabbits were immunized with the antiserum. A high titre of MPA antibodies was detected 6 months after immunization. Serum from the rabbit with the highest titre of antibodies to MPA was subjected to radioimmunoassay. 7 days after the intramuscular injection of 150 mg Depo-Provera, serum levels of MPA were found in the range of 1750 to 9000 pg/ml. By 75 days, the levels had decreased to 680-2600 pg/ml. The method was found to have adequate accuracy, precision and sensitivity. PMID:661315

  17. Breast cancer and depot-medroxyprogesterone acetate

    PubMed Central

    1985-01-01

    The preliminary results of a study of the incidence of breast cancer in relation to use of depot-medroxyprogesterone acetate (DMPA) are presented. The findings are based on data from three participating centres in Thailand, and one each in Kenya and Mexico. A relative risk for breast cancer of 0.7 was observed in women who had ever used DMPA; this was not statistically significant. Although no consistent decrease in risk with duration of use was observed, the lowest relative risk (0.5) was observed in women who had used DMPA for three or more years. These findings are based on small numbers and must be considered preliminary. However, they provide no evidence that DMPA increases the risk of breast cancer, and suggest that it may exert a protective effect, particularly in long-term users. PMID:2931206

  18. Synthesis and regeneration of lead (IV) acetate

    SciTech Connect

    Boyle, T.J.; Al-Shareef, H.N.; Moore, G.J.

    1996-11-01

    Lead acetate [Pb(O{sub 2}CMe){sub 4}] was easily synthesized from a warm solution of Pb{sub 3}O{sub 4}, HO{sub 2}CMe and O(OCMe){sub 2} following literature preparations when the appropriate measures to minimize water contamination were followed. Furthermore, Pb(O{sub 2}CMe){sub 4} which has been decomposed (evidenced by the appearance of a purple color due to oxidation) can be regenerated using a similar preparatory route. Introduction of Pb(O{sub 2}CMe){sub 4} from the two routes outlined above into the IMO process for production of PZT thin films gave films with comparable ferroelectric properties to commercially available Pb(O{sub 2}CMe){sub 4} precursors. However, the freshly synthesized material yields PZT films with better properties compared to the recycled material.

  19. Nomegestrol acetate and vascular reactivity: nonhuman primate experiments.

    PubMed

    Paris, J M; Williams, K J; Hermsmeyer, K R; Delansorne, R

    2000-01-01

    Prevention of coronary artery disease has been recognized as a major benefit of estrogen replacement therapy (ERT) in postmenopausal women. However, endometrial hyperplasia induced by unopposed ERT has raised important safety concerns. Progesterone or synthetic progestins have been used in combined hormone replacement therapy (HRT) to prevent endometrial cancer risk. Therefore, a major concern has been to ensure that the vascular beneficial effects of estrogens are not opposed when combined with progestins. Nomegestrol acetate (NOMAC) is an orally active progestin widely prescribed for HRT. Its vascular effects were evaluated in two models of coronary vascular reactivity in primates: 1) the paradoxical vasoconstriction to acetylcholine (Ach) coronary infusion after 5 months of mildly atherogenic diet in ovariectomized (OVX) Cynomolgus monkeys and 2) the pharmacologically evoked coronary vasospasm in the OVX Rhesus monkey. In the first model, after 3 months of continuous oral administration in the diet at 0.1 mg/kg/day, E2 prevented the paradoxical response to Ach, alone as well as combined with 0.25 mg/kg/day NOMAC, whereas NOMAC counteracted the endometrial stimulation. In the second model, after one artificial cycle consisting of 28 days of E2 subcutaneous (s.c.) implant and of daily oral gavage with 1 mg/kg/day of NOMAC for the last 14 days, no vasospasm (0 of 11 tested animals) occurred when the complete challenge protocol, including serotonin and the thromboxane agonist U46619, was administered to OVX Rhesus monkeys. In the balanced crossover design, identical artificial cycles with medroxyprogesterone acetate (MPA) at the same dose resulted in 7 vasospasms in 12 animals. In parallel, effective progestative activity was demonstrated by a secretory pattern in endometrial sections obtained at the end of the cycle. In these two nonhuman primate cardiovascular models, NOMAC did not have the negating effects observed with MPA. PMID:11108868

  20. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    NASA Technical Reports Server (NTRS)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  1. Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

    DOEpatents

    Ramprasad, Dorai; Waller, Francis Joseph

    1999-01-01

    This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

  2. Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

    DOEpatents

    Ramprasad, D.; Waller, F.J.

    1999-04-06

    This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

  3. Tightly bound trions in monolayer MoS2

    NASA Astrophysics Data System (ADS)

    Mak, Kin Fai; He, Keliang; Lee, Changgu; Lee, Gwan Hyoung; Hone, James; Heinz, Tony F.; Shan, Jie

    2013-03-01

    Two-dimensional (2D) atomic crystals, such as graphene and transition-metal dichalcogenides, have emerged as a new class of materials with remarkable physical properties. In contrast to graphene, monolayer MoS2 is a non-centrosymmetric material with a direct energy gap. Strong photoluminescence, a current on/off ratio exceeding 108 in field-effect transistors, and efficient valley and spin control by optical helicity have recently been demonstrated in this material. Here we report the spectroscopic identification in a monolayer MoS2 field-effect transistor of tightly bound negative trions, a quasiparticle composed of two electrons and a hole. These quasiparticles, which can be optically created with valley and spin polarized holes, have no analogue in conventional semiconductors. They also possess a large binding energy (~ 20 meV), rendering them significant even at room temperature. Our results open up possibilities both for fundamental studies of many-body interactions and for optoelectronic and valleytronic applications in 2D atomic crystals.

  4. A tight-binding study of single-atom transistors.

    PubMed

    Ryu, Hoon; Lee, Sunhee; Fuechsle, Martin; Miwa, Jill A; Mahapatra, Suddhasatta; Hollenberg, Lloyd C L; Simmons, Michelle Y; Klimeck, Gerhard

    2015-01-21

    A detailed theoretical study of the electronic and transport properties of a single atom transistor, where a single phosphorus atom is embedded within a single crystal transistor architecture, is presented. Using a recently reported deterministic single-atom transistor as a reference, the electronic structure of the device is represented atomistically with a tight-binding model, and the channel modulation is simulated self-consistently with a Thomas-Fermi method. The multi-scale modeling approach used allows confirmation of the charging energy of the one-electron donor charge state and explains how the electrostatic environments of the device electrodes affects the donor confinement potential and hence extent in gate voltage of the two-electron charge state. Importantly, whilst devices are relatively insensitive to dopant ordering in the highly doped leads, a ∼1% variation of the charging energy is observed when a dopant is moved just one lattice spacing within the device. The multi-scale modeling method presented here lays a strong foundation for the understanding of single-atom device structures: essential for both classical and quantum information processing. PMID:25293353

  5. Paroxysmal dystonic choreoathetosis: Tight linkage to chromosome 2q

    SciTech Connect

    Fink, J.K.; Rainier, S.; Wilkowski, J.; Jones, S.M.

    1996-07-01

    Paroxysmal dystonic choreoathetosis (PDC) is characterized by attacks of involuntary movements that last up to several hours and occur at rest both spontaneously and following caffeine or alcohol consumption. We analyzed a Polish-American kindred with autosomal dominant PDC and identified tight linkage between the disorder and microsatellite markers on chromosome 2q (maximum two-point LOD score 4.77; recombination fraction 0). Our results clearly establish the existence of a locus for autosomal dominant PDC on distal chromosome 2q. The fact that three other paroxysmal neurological disorders (periodic ataxia with myokymia and hypo- and hyperkalemic periodic paralysis) are due to mutation in ion-channel genes raises the possibility that PDC is also due to an ion-channel gene mutation. It is noteworthy that a cluster of sodium-channel genes is located on distal chromosome 2q, near the PDC locus. Identifying the PDC locus on chromosome 2q will facilitate discovery whether PDC is genetically homogeneous and whether other paroxysmal movement disorders are also genetically linked to the PDC locus. 28 refs., 2 figs., 1 tab.

  6. Role of Microscopic Flexibility in Tightly Curved DNA

    PubMed Central

    2015-01-01

    The genetic material in living cells is organized into complex structures in which DNA is subjected to substantial contortions. Here we investigate the difference in structure, dynamics, and flexibility between two topological states of a short (107 base pair) DNA sequence in a linear form and a covalently closed, tightly curved circular DNA form. By employing a combination of all-atom molecular dynamics (MD) simulations and elastic rod modeling of DNA, which allows capturing microscopic details while monitoring the global dynamics, we demonstrate that in the highly curved regime the microscopic flexibility of the DNA drastically increases due to the local mobility of the duplex. By analyzing vibrational entropy and Lipari–Szabo NMR order parameters from the simulation data, we propose a novel model for the thermodynamic stability of high-curvature DNA states based on vibrational untightening of the duplex. This novel view of DNA bending provides a fundamental explanation that bridges the gap between classical models of DNA and experimental studies on DNA cyclization, which so far have been in substantial disagreement. PMID:25155114

  7. Prediction of Gas Leak Tightness of Superplastically Formed Products

    NASA Astrophysics Data System (ADS)

    Snippe, Corijn H. C.; Meinders, T.

    2010-06-01

    In some applications, in this case an aluminium box in a subatomic particle detector containing highly sensitive detecting devices, it is important that a formed sheet should show no gas leak from one side to the other. In order to prevent a trial-and-error procedure to make this leak tight box, a method is set up to predict if a formed sheet conforms to the maximum leak constraint. The technique of superplastic forming (SPF) is used in order to attain very high plastic strains before failure. Since only a few of these boxes are needed, this makes, this generally slow, process an attractive production method. To predict the gas leak of a superplastically formed aluminium sheet in an accurate way, finite element simulations are used in combination with a user-defined material model. This constitutive model couples the leak rate with the void volume fraction. This void volume fraction is then dependent on both the equivalent plastic strain and the applied hydrostatic pressure during the bulge process (backpressure).

  8. Analytical approach to atomic multichannel collisions in tight harmonic waveguides

    NASA Astrophysics Data System (ADS)

    Heß, Benjamin; Giannakeas, Panagiotis; Schmelcher, Peter

    2015-08-01

    We perform an analytical investigation in the framework of generalized K -matrix theory of the scattering problem in tight isotropic and harmonic waveguides allowing for several open scattering channels. The scattering behavior is explored for identical bosons and fermions, as well as for distinguishable particles, the main aspect being the confinement-induced resonances (CIR) which are attributed to different partial waves. In particular, we present the unitarity bounds which emerge when considering a quasi-one-dimensional system. Unitarity bounds are also given for the transition coefficients, which show the limitations for efficient transversal (de)excitations by means of CIRs. We analyze the CIR for d waves and find the intriguing phenomenon of a strong transmission suppression in the presence of more than one open channel, which represents an interesting regime to be applied in the corresponding many-particle systems. The corresponding channel threshold singularities are studied and it is shown that these are solely determined by the symmetry class of the partial wave.

  9. Emerging Multifunctional Roles of Claudin Tight Junction Proteins in Bone

    PubMed Central

    Alshbool, Fatima. Z.

    2014-01-01

    The imbalance between bone formation and resorption during bone remodeling has been documented to be a major factor in the pathogenesis of osteoporosis. Recent evidence suggests a significant role for the tight junction proteins, Claudins (Cldns), in the regulation of bone remodeling processes. In terms of function, whereas Cldns act “canonically” as key determinants of paracellular permeability, there is considerable recent evidence to suggest that Cldns also participate in cell signaling, ie, a “noncanonical function”. To this end, Cldns have been shown to regulate cell proliferation, differentiation, and gene expression in a variety of cell types. The present review will discuss Cldns' structure, their expression profile, regulation of expression, and their canonical and non- canonical functions in general with special emphasis on bone cells. In order to shed light on the noncanonical functions of Cldns in bone, we will highlight the role of Cldn-18 in regulating bone resorption and osteoclast differentiation. Collectively, we hope to provide a framework for guiding future research on understanding how Cldns modulate osteoblast and osteoclast function and overall bone homeostasis. Such studies should provide valuable insights into the pathogenesis of osteoporosis, and may highlight Cldns as novel targets for the diagnosis and therapeutic management of osteoporosis. PMID:24758302

  10. Phononic crystals of spherical particles: A tight binding approach

    SciTech Connect

    Mattarelli, M.; Secchi, M.; Dipartimento di Fisica, Università di Trento, Via Sommarive 14, 38123 Trento ; Montagna, M.

    2013-11-07

    The vibrational dynamics of a fcc phononic crystal of spheres is studied and compared with that of a single free sphere, modelled either by a continuous homogeneous medium or by a finite cluster of atoms. For weak interaction among the spheres, the vibrational dynamics of the phononic crystal is described by shallow bands, with low degree of dispersion, corresponding to the acoustic spheroidal and torsional modes of the single sphere. The phonon displacements are therefore related to the vibrations of a sphere, as the electron wave functions in a crystal are related to the atomic wave functions in a tight binding model. Important dispersion is found for the two lowest phonon bands, which correspond to zero frequency free translation and rotation of a free sphere. Brillouin scattering spectra are calculated at some values of the exchanged wavevectors of the light, and compared with those of a single sphere. With weak interaction between particles, given the high acoustic impedance mismatch in dry systems, the density of phonon states consist of sharp bands separated by large gaps, which can be well accounted for by a single particle model. Based on the width of the frequency gaps, tunable with the particle size, and on the small number of dispersive acoustic phonons, such systems may provide excellent materials for application as sound or heat filters.

  11. Environmental Public Health Dimensions of Shale and Tight Gas Development

    PubMed Central

    Hays, Jake; Finkel, Madelon L.

    2014-01-01

    Background: The United States has experienced a boom in natural gas production due to recent technological innovations that have enabled this resource to be produced from shale formations. Objectives: We reviewed the body of evidence related to exposure pathways in order to evaluate the potential environmental public health impacts of shale gas development. We highlight what is currently known and identify data gaps and research limitations by addressing matters of toxicity, exposure pathways, air quality, and water quality. Discussion: There is evidence of potential environmental public health risks associated with shale gas development. Several studies suggest that shale gas development contributes to ambient air concentrations of pollutants known to be associated with increased risk of morbidity and mortality. Similarly, an increasing body of studies suggest that water contamination risks exist through a variety of environmental pathways, most notably during wastewater transport and disposal, and via poor zonal isolation of gases and fluids due to structural integrity impairment of cement in gas wells. Conclusion: Despite a growing body of evidence, data gaps persist. Most important, there is a need for more epidemiological studies to assess associations between risk factors, such as air and water pollution, and health outcomes among populations living in close proximity to shale gas operations. Citation: Shonkoff SB, Hays J, Finkel ML. 2014. Environmental public health dimensions of shale and tight gas development. Environ Health Perspect 122:787–795; http://dx.doi.org/10.1289/ehp.1307866 PMID:24736097

  12. Rationalizing Tight Ligand Binding through Cooperative Interaction Networks

    PubMed Central

    2011-01-01

    Small modifications of the molecular structure of a ligand sometimes cause strong gains in binding affinity to a protein target, rendering a weakly active chemical series suddenly attractive for further optimization. Our goal in this study is to better rationalize and predict the occurrence of such interaction hot-spots in receptor binding sites. To this end, we introduce two new concepts into the computational description of molecular recognition. First, we take a broader view of noncovalent interactions and describe protein–ligand binding with a comprehensive set of favorable and unfavorable contact types, including for example halogen bonding and orthogonal multipolar interactions. Second, we go beyond the commonly used pairwise additive treatment of atomic interactions and use a small world network approach to describe how interactions are modulated by their environment. This approach allows us to capture local cooperativity effects and considerably improves the performance of a newly derived empirical scoring function, ScorpionScore. More importantly, however, we demonstrate how an intuitive visualization of key intermolecular interactions, interaction networks, and binding hot-spots supports the identification and rationalization of tight ligand binding. PMID:22087588

  13. Giant stretchability and reversibility of tightly wound helical carbon nanotubes.

    PubMed

    Wu, Jianyang; He, Jianying; Odegard, Gregory M; Nagao, Shijo; Zheng, Quanshui; Zhang, Zhiliang

    2013-09-18

    There is a surging interest in 3D graphitic nanostructures which possess outstanding properties enabling them to be prime candidates for a new generation of nanodevices and energy-absorbing materials. Here we study the stretching instability and reversibility of tightly wound helical carbon nanotubes (HCNTs) by atomistic simulations. The intercoil van der Waals (vdW) interaction-induced flattening of HCNT walls prior to loading is constrained by the defects coordinated for the curvature formation of helices. The HCNTs exhibit extensive stretchability in the range from 400% to 1000% as a result of two distinct deformation mechanisms depending on the HCNT size. For small HCNTs tremendous deformation is achieved by domino-type partial fracture events, whereas for large HCNTs this is accomplished by stepwise buckling of coils. The formation and fracture of edge-closed graphene ribbons occur at lower temperatures, while at elevated temperatures the highly distributed fracture realizes a phenomenal stretchability. The results of cyclic stretching-reversing simulations of large HCNTs display pronounced hysteresis loops, which produce large energy dissipation via full recovery of buckling and vdW bondings. This study provides physical insights into the origins of high ductility and superior reversibility of hybrid CNT structures. PMID:24016308

  14. Tight-binding model for secondary-ion emission

    SciTech Connect

    Gagliano, E.R.; Goldberg, E.C.; Passeggi, M.C.G.; Ferron, J.

    1985-06-01

    The ionization probability R/sup +/ of atoms ejected from sputtered solid surfaces is analyzed by means of the perturbed-stationary-state method. The system is simulated by a linear cluster in the tight-binding approximation including two kinds of time-dependent parameters: the interaction between the sputtered atom and its nearest neighbor, as well as their site energies. The dynamical wave function is described in terms of a superposition of the molecular eigenstates at each point of the trajectory. A direct analysis of the energies of the molecular orbitals (MO's) allows one to retain only those states whose coupling with the MO which evolves into the atomic state of the ejected atom, and determine the ionization probability, thus reducing the size of the coupled system of equations to be considered. Consequently, the cluster can be taken large enough as to reproduce the bandwidth of a semi-infinite chain, allowing for a selection of parameters which simulate simple metals. We studied R/sup +/ as a function of the velocity of the ejected atom and also its dependence with the work function phi of the substrate. For large velocities or for values phi near to the ionization level of the sputtered atom, an exponential dependence of R/sup +/ is found in both cases.

  15. Stability of spinor Fermi gases in tight waveguides

    SciTech Connect

    Campo, A. del; Muga, J. G.; Girardeau, M. D.

    2007-07-15

    The two- and three-body correlation functions of the ground state of an optically trapped ultracold spin-(1/2) Fermi gas (SFG) in a tight waveguide [one-dimensional (1D) regime] are calculated in the plane of even- and odd-wave coupling constants, assuming a 1D attractive zero-range odd-wave interaction induced by a 3D p-wave Feshbach resonance, as well as the usual repulsive zero-range even-wave interaction stemming from 3D s-wave scattering. The calculations are based on the exact mapping from the SFG to a 'Lieb-Liniger-Heisenberg' model with delta-function repulsions depending on isotropic Heisenberg spin-spin interactions, and indicate that the SFG should be stable against three-body recombination in a large region of the coupling constant plane encompassing parts of both the ferromagnetic and antiferromagnetic phases. However, the limiting case of the fermionic Tonks-Girardeau gas, a spin-aligned 1D Fermi gas with infinitely attractive p-wave interactions, is unstable in this sense. Effects due to the dipolar interaction and a Zeeman term due to a resonance-generating magnetic field do not lead to shrinkage of the region of stability of the SFG.

  16. Tight Junction Proteins in Human Schwann Cell Autotypic Junctions

    PubMed Central

    Alanne, Maria H.; Pummi, Kati; Heape, Anthony M.; Grènman, Reidar; Peltonen, Juha; Peltonen, Sirkku

    2009-01-01

    Tight junctions (TJs) form physical barriers in various tissues and regulate paracellular transport of ions, water, and molecules. Myelinating Schwann cells form highly organized structures, including compact myelin, nodes of Ranvier, paranodal regions, Schmidt-Lanterman incisures, periaxonal cytoplasmic collars, and mesaxons. Autotypic TJs are formed in non-compacted myelin compartments between adjacent membrane lamellae of the same Schwann cell. Using indirect immunofluorescence and RT-PCR, we analyzed the expression of adherens junction (E-cadherin) and TJ [claudins, zonula occludens (ZO)-1, occludin] components in human peripheral nerve endoneurium, showing clear differences with published rodent profiles. Adult nerve paranodal regions contained E-cadherin, claudin-1, claudin-2, and ZO-1. Schmidt-Lanterman incisures contained E-cadherin, claudin-1, claudin-2, claudin-3, claudin-5, ZO-1, and occludin. Mesaxons contained E-cadherin, claudin-1, claudin-2, claudin-3, ZO-1, and occludin. None of the proteins studied were associated with nodal inter-Schwann cell junctions. Fetal nerve expression of claudin-1, claudin-3, ZO-1, and occludin was predominantly punctate, with a mesaxonal labeling pattern, but paranodal (ZO-1, claudin-3) and Schmidt-Lanterman incisure (claudins-1 and -3) expression profiles typical of compact myelin were visible by gestational week 37. The clear differences observed between human and published rodent nerve profiles emphasize the importance of human studies when translating the results of animal models to human diseases. (J Histochem Cytochem 57:523–529, 2009) PMID:19153196

  17. Diagnosing the tight building syndrome or diagnosing chemical hypersensitivity

    SciTech Connect

    Rogers, S.A. )

    1989-01-01

    The abrupt exposure to urea foam formaldehyde insulation served as an alert to its spectrum of symptoms, including attacks of headache, flushing, laryngitis, dizziness, nausea, extreme weakness or exhaustion, arthralgia, an inability to concentrate, unwarranted depression, arrhythmia, or muscle spasms, and baffled physicians from many specialties. Later it was learned that toluene, xylene, benzene, natural gas, trichloroethylene, and many other chemicals were also capable of triggering chemical hypersensitivity. Other names for this condition include Environmentally Induced Illness (EI), the Tight Building Syndrome (TBS), the Sick Building Syndrome, and Building-Related Illness. The very symptoms patients complain of can be provoked within minutes and then subsequently alleviated with an intradermal injection of the appropriate strength of the triggering chemical. This technique aids in convincing the patient of the EI or TBS triggers so that the patient can begin to relate symptoms to environmental exposures and initiate measure to bring the disease under control. The key to safer buildings is increased ventilation, increased filtration of air, and decreased use of off-gassing synthetic materials.

  18. Effect of nitrate, acetate and hydrogen on native perchlorate-reducing microbial communities and their activity in vadose soil

    PubMed Central

    Nozawa-Inoue, Mamie; Jien, Mercy; Yang, Kun; Rolston, Dennis E.; Hristova, Krassimira R.; Scow, Kate M.

    2011-01-01

    Effect of nitrate, acetate and hydrogen on native perchlorate-reducing bacteria (PRB) was examined by conducting microcosm tests using vadose soil collected from a perchlorate-contaminated site. The rate of perchlorate reduction was enhanced by hydrogen amendment and inhibited by acetate amendment, compared to unamendment. Nitrate was reduced before perchlorate in all amendments. In hydrogen-amended and unamended soils, nitrate delayed perchlorate reduction, suggesting the PRB preferentially use nitrate as an electron acceptor. In contrast, nitrate eliminated the inhibitory effect of acetate amendment on perchlorate reduction and increased the rate and the extent, possibly because the preceding nitrate reduction/denitrification decreased the acetate concentration which was inhibitory to the native PRB. In hydrogen-amended and unamended soils, perchlorate reductase gene (pcrA) copies, representing PRB densities, increased with either perchlorate or nitrate reduction, suggesting either perchlorate or nitrate stimulates growth of the PRB. In contrast, in acetate-amended soil pcrA increased only when perchlorate was depleted: a large portion of the PRB may have not utilized nitrate in this amendment. Nitrate addition did not alter the distribution of the dominant pcrA clones in hydrogen-amended soil, likely because of the functional redundancy of PRB as nitrate-reducers/denitrifiers, whereas acetate selected different pcrA clones from those with hydrogen amendment. PMID:21284679

  19. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    PubMed

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure. PMID:23477409

  20. Homogeneous gold-catalyzed efficient oxidative dimerization of propargylic acetates.

    PubMed

    Cui, Li; Zhang, Guozhu; Zhang, Liming

    2009-07-15

    A highly efficient gold-catalyzed oxidative dimerization of propargylic acetates is developed. In this chemistry, Selectfluor oxidation of Au(I) to Au(III) is readily incorporated into Au-catalyzed tandem reactions of propargylic acetates, and transmetallation and reductive elimination on Au(III) intermediates are likely involved. PMID:19362834

  1. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ANIMAL DRUGS § 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone acetate... feed efficiency. (C) Limitations. Implant subcutaneously in ear only. Safety and effectiveness have...

  2. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ANIMAL DRUGS § 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone acetate... feed efficiency. (C) Limitations. Implant subcutaneously in ear only. Safety and effectiveness have...

  3. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ANIMAL DRUGS § 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone acetate... feed efficiency. (C) Limitations. Implant subcutaneously in ear only. Safety and effectiveness have...

  4. 21 CFR 522.2478 - Trenbolone acetate and estradiol benzoate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ANIMAL DRUGS § 522.2478 Trenbolone acetate and estradiol benzoate. (a) Specifications. Each implant dose...) For an implant as described in paragraph (a)(1) of this section: (A) Amount. 200 mg trenbolone acetate... feed efficiency. (C) Limitations. Implant subcutaneously in ear only. Safety and effectiveness have...

  5. Transition-Metal-Catalyzed Carbonylation of Methyl Acetate.

    ERIC Educational Resources Information Center

    Polichnowski, S. W.

    1986-01-01

    Presents a study of the rhodium-catalyzed, ioding-promoted carbonylation of methyl acetate. This study provides an interesting contrast between the carbonylation of methyl acetate and the carbonylation of methanol when similar rhodium/iodine catalyst systems are used. (JN)

  6. Proteomic Analysis on Acetate Metabolism in Citrobacter sp. BL-4

    PubMed Central

    Kim, Young-Man; Lee, Sung-Eun; Park, Byeoung-Soo; Son, Mi-Kyung; Jung, Young-Mi; Yang, Seung-Ok; Choi, Hyung-Kyoon; Hur, Sung-Ho; Yum, Jong Hwa

    2012-01-01

    Mass production of glucosamine (GlcN) using microbial cells is a worthy approach to increase added values and keep safety problems in GlcN production process. Prior to set up a microbial cellular platform, this study was to assess acetate metabolism in Citrobacter sp. BL-4 (BL-4) which has produced a polyglucosamine PGB-2. The LC-MS analysis was conducted after protein separation on the 1D-PAGE to accomplish the purpose of this study. 280 proteins were totally identified and 188 proteins were separated as acetate-related proteins in BL-4. Acetate was converted to acetyl-CoA by acetyl-CoA synthetase up-regulated in the acetate medium. The glyoxylate bypass in the acetate medium was up-regulated with over-expression of isocitrate lyases and 2D-PAGE confirmed this differential expression. Using 1H-NMR analysis, the product of isocitrate lyases, succinate, increased about 15 times in the acetate medium. During acetate metabolism proteins involved in the lipid metabolism and hexosamine biosynthesis were over-expressed in the acetate medium, while proteins involved in TCA cycle, pentose phosphate cycle and purine metabolism were down-regulated. Taken together, the results from the proteomic analysis can be applied to improve GlcN production and to develop metabolic engineering in BL-4. PMID:22211106

  7. 21 CFR 182.8892 - α-Tocopherol acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false α-Tocopherol acetate. 182.8892 Section 182.8892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8892 α-Tocopherol acetate. (a) Product....

  8. 21 CFR 522.960b - Flumethasone acetate injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Flumethasone acetate injection. 522.960b Section 522.960b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.960b Flumethasone acetate injection....

  9. 21 CFR 522.960b - Flumethasone acetate solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Flumethasone acetate solution. 522.960b Section 522.960b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.960b Flumethasone acetate solution....

  10. 40 CFR 721.303 - Substituted acetate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.303 Substituted acetate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted acetate (PMN...

  11. 40 CFR 721.303 - Substituted acetate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.303 Substituted acetate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted acetate (PMN...

  12. Triacetin-based acetate supplementation as a chemotherapeutic adjuvant therapy in glioma

    PubMed Central

    Tsen, Andrew R.; Long, Patrick M.; Driscoll, Heather E.; Davies, Matthew T.; Teasdale, Benjamin A.; Penar, Paul L.; Pendlebury, William W.; Spees, Jeffrey L.; Lawler, Sean E.; Viapiano, Mariano S.; Jaworski, Diane M.

    2013-01-01

    Cancer is associated with epigenetic (i.e., histone hypoacetylation) and metabolic (i.e., aerobic glycolysis) alterations. Levels of N-acetyl-L-aspartate (NAA), the primary storage form of acetate in the brain, and aspartoacylase (ASPA), the enzyme responsible for NAA catalysis to generate acetate, are reduced in glioma; yet, few studies have investigated acetate as a potential therapeutic agent. This preclinical study sought to test the efficacy of the food additive Triacetin (glyceryl triacetate, GTA) as a novel therapy to increase acetate bioavailability in glioma cells. The growth-inhibitory effects of GTA, compared to the histone deacetylase inhibitor Vorinostat (SAHA), were assessed in established human glioma cell lines (HOG and Hs683 oligodendroglioma, U87 and U251 glioblastoma) and primary tumor-derived glioma stem-like cells (GSCs), relative to an oligodendrocyte progenitor line (Oli-Neu), normal astrocytes, and neural stem cells (NSCs) in vitro. GTA was also tested as a chemotherapeutic adjuvant with temozolomide (TMZ) in orthotopically grafted GSCs. GTA induced cytostatic growth arrest in vitro comparable to Vorinostat, but, unlike Vorinostat, GTA did not alter astrocyte growth and promoted NSC expansion. GTA alone increased survival of mice engrafted with glioblastoma GSCs and potentiated TMZ to extend survival longer than TMZ alone. GTA was most effective on GSCs with a mesenchymal cell phenotype. Given that GTA has been chronically administered safely to infants with Canavan disease, a leukodystrophy due to ASPA mutation, GTA-mediated acetate supplementation may provide a novel, safe chemotherapeutic adjuvant to reduce the growth of glioma tumors, most notably the more rapidly proliferating, glycolytic, and hypoacetylated mesenchymal glioma tumors. PMID:23996800

  13. Improved Helicopter Rotor Performance Prediction through Loose and Tight CFD/CSD Coupling

    NASA Astrophysics Data System (ADS)

    Ickes, Jacob C.

    of improved peak/trough magnitude prediction, better phase prediction of these locations, and a predicted signal with a frequency content more like the flight test data than the CSD code acting alone. Additionally, a tight coupling analysis was performed as a demonstration of the capability and unique aspects of such an analysis. This work shows that away from the center of the flight envelope, the aerodynamic modeling of the CSD code can be replaced with a more accurate set of predictions from a CFD code with an improvement in the aerodynamic results. The better predictions come at substantially increased computational costs between 1,000 and 10,000 processor-hours.

  14. A Simplified Baseband Prefilter Model with Adaptive Kalman Filter for Ultra-Tight COMPASS/INS Integration

    PubMed Central

    Luo, Yong; Wu, Wenqi; Babu, Ravindra; Tang, Kanghua; Luo, Bing

    2012-01-01

    COMPASS is an indigenously developed Chinese global navigation satellite system and will share many features in common with GPS (Global Positioning System). Since the ultra-tight GPS/INS (Inertial Navigation System) integration shows its advantage over independent GPS receivers in many scenarios, the federated ultra-tight COMPASS/INS integration has been investigated in this paper, particularly, by proposing a simplified prefilter model. Compared with a traditional prefilter model, the state space of this simplified system contains only carrier phase, carrier frequency and carrier frequency rate tracking errors. A two-quadrant arctangent discriminator output is used as a measurement. Since the code tracking error related parameters were excluded from the state space of traditional prefilter models, the code/carrier divergence would destroy the carrier tracking process, and therefore an adaptive Kalman filter algorithm tuning process noise covariance matrix based on state correction sequence was incorporated to compensate for the divergence. The federated ultra-tight COMPASS/INS integration was implemented with a hardware COMPASS intermediate frequency (IF), and INS's accelerometers and gyroscopes signal sampling system. Field and simulation test results showed almost similar tracking and navigation performances for both the traditional prefilter model and the proposed system; however, the latter largely decreased the computational load. PMID:23012564

  15. Culture strategies for lipid production using acetic acid as sole carbon source by Rhodosporidium toruloides.

    PubMed

    Huang, Xiang-Feng; Liu, Jia-Nan; Lu, Li-Jun; Peng, Kai-Ming; Yang, Gao-Xiang; Liu, Jia

    2016-04-01

    Rhodosporidium toruloides AS 2.1389 was tested using different concentrations of acetic acid as a low-cost carbon source for the production of microbial lipids, which are good raw materials for biodiesel production. It grew and had higher lipid contents in media containing 4-20g/L acetic acid as the sole carbon source, compared with that in glucose-containing media under the same culture conditions. At acetic acid concentrations as high as 20g/L and the optimal carbon-to-nitrogen ratio (C/N) of 200 in a batch culture, the highest biomass production was 4.35g/L, with a lipid content of 48.2%. At acetic acid concentrations as low as 4g/L, a sequencing batch culture (SBC) with a C/N of 100 increased biomass production to 4.21g/L, with a lipid content of 38.6%. These results provide usable culture strategies for lipid production by R. toruloides AS 2.1389 when using diverse waste-derived volatile fatty acids. PMID:26851898

  16. Isoeugenol is an important contact allergen: can it be safely replaced with isoeugenyl acetate?

    PubMed

    White, I R; Johansen, J D; Arnau, E G; Lepoittevin, J P; Rastogi, S; Bruze, M; Andersen, K E; Frosch, P J; Goossens, A; Menné, T

    1999-11-01

    The prevalence of contact allergy to the fragrance mix in individuals with eczema is up to 10%. Within the mix, isoeugenol (CAS 97-54-1) is an important individual allergen. Until May 1998, the IFRA (International Fragrance Association) guidelines suggested that isoeugenol could safely be used at a level of 0.2% in consumer products. In May 1998, IFRA recommended that isoeugenol should not be used at a level that exceeds 0.02% in consumer products, but did not provide guidance on allergen substitution. An alternative to isoeugenol, based on aroma and absence of guidelines on use, is isoeugenyl acetate (CAS 93-29-8). 155 consecutive subjects were patch tested to isoeugenyl acetate (1.2%, 0.4%, 0.13% eth.) and isoeugenol 1% pet. 6 (3.9%) had an allergic reaction to 1.2% isoeugenyl acetate at D4. The reactions to the other 2 dilutions tended to be graded. 8 individuals had at least a palpable erythema by D4 to isoeugenol 1% pet. The majority of individuals allergic to isoeugenol were also intolerant of isoeugenyl acetate. Effective labelling of fragrance substances on consumer products will facilitate monitoring of exposure. PMID:10554062

  17. Structure-odor relationships of linalool, linalyl acetate and their corresponding oxygenated derivatives

    NASA Astrophysics Data System (ADS)

    Elsharif, Shaimaa; Banerjee, Ashutosh; Buettner, Andrea

    2015-10-01

    Linalool 1 is an odorant that is commonly perceived as having a pleasant odor, but is also known to elicit physiological effects such as inducing calmness and enhancing sleep. However, no comprehensive studies are at hand to show which structural features are responsible for these prominent effects. Therefore, a total of six oxygenated derivatives were synthesized from both 1 and linalyl acetate 2, and were tested for their odor qualities and relative odor thresholds (OTs) in air. Linalool was found to be the most potent odorant among the investigated compounds, with an average OT of 3.2 ng/L, while the 8-hydroxylinalool derivative was the least odorous compound with an OT of 160 ng/L; 8-carboxylinalool was found to be odorless. The odorant 8-oxolinalyl acetate, which has very similar odor properties to linalool, was the most potent odorant besides linalool, exhibiting an OT of 5.9 ng/L. By comparison, 8-carboxylinalyl acetate had a similar OT (6.1 ng/L) as its corresponding 8-oxo derivative but exhibited divergent odor properties (fatty, greasy, musty). Overall, oxygenation on carbon 8 had a substantial effect on the aroma profiles of structural derivatives of linalool and linalyl acetate.

  18. Structure-odor relationships of linalool, linalyl acetate and their corresponding oxygenated derivatives

    PubMed Central

    Elsharif, Shaimaa A.; Banerjee, Ashutosh; Buettner, Andrea

    2015-01-01

    Linalool 1 is an odorant that is commonly perceived as having a pleasant odor, but is also known to elicit physiological effects such as inducing calmness and enhancing sleep. However, no comprehensive studies are at hand to show which structural features are responsible for these prominent effects. Therefore, a total of six oxygenated derivatives were synthesized from both 1 and linalyl acetate 2, and were tested for their odor qualities and relative odor thresholds (OTs) in air. Linalool was found to be the most potent odorant among the investigated compounds, with an average OT of 3.2 ng/L, while the 8-hydroxylinalool derivative was the least odorous compound with an OT of 160 ng/L; 8-carboxylinalool was found to be odorless. The odorant 8-oxolinalyl acetate, which has very similar odor properties to linalool, was the most potent odorant besides linalool, exhibiting an OT of 5.9 ng/L. By comparison, 8-carboxylinalyl acetate had a similar OT (6.1 ng/L) as its corresponding 8-oxo derivative but exhibited divergent odor properties (fatty, greasy, musty). Overall, oxygenation on carbon 8 had a substantial effect on the aroma profiles of structural derivatives of linalool and linalyl acetate. PMID:26501053

  19. Pharmacokinetics of depot medroxyprogesterone acetate contraception.

    PubMed

    Mishell, D R

    1996-05-01

    Depot medroxyprogesterone acetate (DMPA) is an aqueous suspension of 17-acetoxy 6-methyl progestin administered by intramuscular injection for long-term contraception. This highly effective injectable formulation of medroxyprogesterone acetate (MPA) has a prolonged duration of action since the progestin is released slowly from the muscle. MPA is detected in the serum within 30 minutes after an injection of 150 mg. Serum concentrations vary between individual women but generally plateau at about 1.0 ng/mL for about three months, after which there is a gradual decline. In some women, MPA can be detected in the serum for as long as nine months after a single injection of 150 mg. The circulating MPA initially inhibits the midcycle leutinizing hormone (LH) peak, but LH and follicle stimulating hormone (FSH) levels remain in the range of those for the luteal phase of a pretreatment control cycle. Since ovulation is inhibited, serum progesterone levels remain low (< 0.4 ng/mL) for several months following an injection of DMPA. When MPA levels fall below 0.1 ng/mL, ovulation resumes. Thus, return to fertility is delayed for several months if a woman wishes to conceive after receiving one or more injections of DMPA. Following an injection of DMPA, serum estradiol levels initially are in the early to midfollicular phase range (mean approximately 50 pg/nL). Serum estradiol levels begin to rise about four months after a single injection when MPA levels fall below 0.5 ng/mL. For women who have used DMPA for several years, serum estradiol levels range between 10 and 92 pg/mL, with mean levels of about 40 pg/mL. Despite these low levels of estradiol, hot flushes are a rare event, and the vaginal epithelium remains moist and well rugated. Women using DMPA for several years do not observe a change in breast size. DMPA causes the endometrium to become atrophic, with small, straight endometrial glands and decidualized stroma. The cervical mucus remains thick and viscid. DMPA is a

  20. Acetic acid treatment in S. cerevisiae creates significant energy deficiency and nutrient starvation that is dependent on the activity of the mitochondrial transcriptional complex Hap2-3-4-5

    PubMed Central

    Kitanovic, Ana; Bonowski, Felix; Heigwer, Florian; Ruoff, Peter; Kitanovic, Igor; Ungewiss, Christin; Wölfl, Stefan

    2012-01-01

    Metabolic pathways play an indispensable role in supplying cellular systems with energy and molecular building blocks for growth, maintenance and repair and are tightly linked with lifespan and systems stability of cells. For optimal growth and survival cells rapidly adopt to environmental changes. Accumulation of acetic acid in stationary phase budding yeast cultures is considered to be a primary mechanism of chronological aging and induction of apoptosis in yeast, which has prompted us to investigate the dependence of acetic acid toxicity on extracellular conditions in a systematic manner. Using an automated computer controlled assay system, we investigated and model the dynamic interconnection of biomass yield- and growth rate-dependence on extracellular glucose concentration, pH conditions and acetic acid concentration. Our results show that toxic concentrations of acetic acid inhibit glucose consumption and reduce ethanol production. In absence of carbohydrates uptake, cells initiate synthesis of storage carbohydrates, trehalose and glycogen, and upregulate gluconeogenesis. Accumulation of trehalose and glycogen, and induction of gluconeogenesis depends on mitochondrial activity, investigated by depletion of the Hap2-3-4-5 complex. Analyzing the activity of glycolytic enzymes, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase (PYK), and glucose-6-phosphate dehydrogenase (G6PDH) we found that while high acetic acid concentration increased their activity, lower acetic acids concentrations significantly inhibited these enzymes. With this study we determined growth and functional adjustment of metabolism to acetic acid accumulation in a complex range of extracellular conditions. Our results show that substantial acidification of the intracellular environment, resulting from accumulation of dissociated acetic acid in the cytosol, is required for acetic acid toxicity, which creates a state of energy deficiency and nutrient starvation. PMID:23050242

  1. The clinical use of PET with 11C-acetate

    PubMed Central

    Grassi, Ilaria; Nanni, Cristina; Allegri, Vincenzo; Morigi, Joshua James; Montini, Gian Carlo; Castellucci, Paolo; Fanti, Stefano

    2012-01-01

    The aim of this review is to evaluate clinical applications of 11C-acetate positron emission tomography (PET). Acetate is quickly metabolized into acetyl-CoA in human cells. In this form it can either enter into the tricarboxylic acid cycle, thus producing energy, as happens in the myocardium, or participate in cell membrane lipid synthesis, as happens in tumor cells. 11C-acetate PET was originally employed in cardiology, to study myocardial oxygen metabolism. More recently it has also been used to evaluate myocardial perfusion, as well as in oncology. The first studies of 11C-acetate focused on its use in prostate cancer. Subsequently, 11C-acetate was studied in other urological malignancies, as well as renal cell carcinoma and bladder cancer. Well differentiated hepatocellular carcinoma represents an 18F-fluoro-deoxyglucose (18F-FDG) PET pitfall, so many authors have proposed to use 11C-acetate in addition to 18F-FDG in studying this tumor. 11C-acetate PET has also been used in other malignancies, such as brain tumors and lung carcinoma. Some authors reported a few cases in which 11C-acetate PET incidentally found multiple myeloma or rare tumors, such as thymoma, multicentric angiomyolipoma of the kidney and cerebellopontine angle schwannoma. Lastly, 11C-acetate PET was also employed in a differential diagnosis case between glioma and encephalitis. The numerous studies on 11C-acetate have demonstrated that it can be used in cardiology and oncology with no contraindications apart from pregnancy and the necessity of a rapid scan. Despite its limited availability, this tracer can surely be considered to be a promising one, because of its versatility and capacity to even detect non 18F-FDG-avid neoplasm, such as differentiated lung cancer or hepatocellular carcinoma. PMID:23133801

  2. Fermentation of lignocellulosic sugars to acetic acid by Moorella thermoacetica.

    PubMed

    Ehsanipour, Mandana; Suko, Azra Vajzovic; Bura, Renata

    2016-06-01

    A systematic study of bioconversion of lignocellulosic sugars to acetic acid by Moorella thermoacetica (strain ATCC 39073) was conducted. Four different water-soluble fractions (hydrolysates) obtained after steam pretreatment of lignocellulosic biomass were selected and fermented to acetic acid in batch fermentations. M. thermoacetica can effectively ferment xylose and glucose in hydrolysates from wheat straw, forest residues, switchgrass, and sugarcane straw to acetic acid. Xylose and glucose were completely utilized, with xylose being consumed first. M. thermoacetica consumed up to 62 % of arabinose, 49 % galactose and 66 % of mannose within 72 h of fermentation in the mixture of lignocellulosic sugars. The highest acetic acid yield was obtained from sugarcane straw hydrolysate, with 71 % of theoretical yield based on total sugars (17 g/L acetic acid from 24 g/L total sugars). The lowest acetic acid yield was observed in forest residues hydrolysate, with 39 % of theoretical yield based on total sugars (18 g/L acetic acid from 49 g/L total sugars). Process derived compounds from steam explosion pretreatment, including 5-hydroxymethylfurfural (0.4 g/L), furfural (0.1 g/L) and total phenolics (3 g/L), did not inhibit microbial growth and acetic acid production yield. This research identified two major factors that adversely affected acetic acid yield in all hydrolysates, especially in forest residues: (i) glucose to xylose ratio and (ii) incomplete consumption of arabinose, galactose and mannose. For efficient bioconversion of lignocellulosic sugars to acetic acid, it is imperative to have an appropriate balance of sugars in a hydrolysate. Hence, the choice of lignocellulosic biomass and steam pretreatment design are fundamental steps for the industrial application of this process. PMID:26992903

  3. Lymphocytes accelerate epithelial tight junction assembly: role of AMP-activated protein kinase (AMPK).

    PubMed

    Tang, Xiao Xiao; Chen, Hao; Yu, Sidney; Zhang, Li; Caplan, Michael J; Chan, Hsiao Chang

    2010-01-01

    The tight junctions (TJs), characteristically located at the apicolateral borders of adjacent epithelial cells, are required for the proper formation of epithelial cell polarity as well as for sustaining the mucosal barrier to the external environment. The observation that lymphocytes are recruited by epithelial cells to the sites of infection [1] suggests that they may play a role in the modulation of epithelial barrier function and thus contribute to host defense. To test the ability of lymphocytes to modulate tight junction assembly in epithelial cells, we set up a lymphocyte-epithelial cell co-culture system, in which Madin-Darby canine kidney (MDCK) cells, a well-established model cell line for studying epithelial TJ assembly [2], were co-cultured with mouse lymphocytes to mimic an infection state. In a typical calcium switch experiment, the TJ assembly in co-culture was found to be accelerated compared to that in MDCK cells alone. This accelaration was found to be mediated by AMP-activated protein kinase (AMPK). AMPK activation was independent of changes in cellular ATP levels but it was found to be activated by the pro-inflammatory cytokine TNF-alpha. Forced suppression of AMPK, either with a chemical inhibitor or by knockdown, abrogated the accelerating effect of lymphocytes on TJ formation. Similar results were also observed in a co-culture with lymphocytes and Calu-3 human airway epithelial cells, suggesting that the activation of AMPK may be a general mechanism underlying lymphocyte-accelerated TJ assembly in different epithelia. These results suggest that signals from lymphocytes, such as cytokines, facilitate TJ assembly in epithelial cells via the activation of AMPK. PMID:20808811

  4. Using tightly-coupled CFD/CSD simulation for rotorcraft stability analysis

    NASA Astrophysics Data System (ADS)

    Zaki, Afifa Adel

    Dynamic stall deeply affects the response of helicopter rotor blades, making its modeling accuracy very important. Two commonly used dynamic stall models were implemented in a comprehensive code, validated, and contrasted to provide improved analysis accuracy and versatility. Next, computational fluid dynamics and computational structural dynamics loose coupling methodologies are reviewed, and a general tight coupling approach was implemented and tested. The tightly coupled computational fluid dynamics and computational structural dynamics methodology is then used to assess the stability characteristics of complex rotorcraft problems. An aeroelastic analysis of rotors must include an assessment of potential instabilities and the determination of damping ratios for all modes of interest. If the governing equations of motion of a system can be formulated as linear, ordinary differential equations with constant coefficients, classical stability evaluation methodologies based on the characteristic exponents of the system can rapidly and accurately provide the system's stability characteristics. For systems described by linear, ordinary differential equations with periodic coefficients, Floquet's theory is the preferred approach. While these methods provide excellent results for simplified linear models with a moderate number of degrees of freedom, they become quickly unwieldy as the number of degrees of freedom increases. Therefore, to accurately analyze rotorcraft aeroelastic periodic systems, a fully nonlinear, coupled simulation tool is used to determine the response of the system to perturbations about an equilibrium configuration and determine the presence of instabilities and damping ratios. The stability analysis is undertaken using an algorithm based on a Partial Floquet approach that has been successfully applied with computational structural dynamics tools on rotors and wind turbines. The stability analysis approach is computationally inexpensive and consists

  5. Na+ transport by rabbit urinary bladder, a tight epithelium.

    PubMed

    Lewis, S A; Diamond, J M

    1976-08-27

    By in vitro experiments on rabbit bladder, we reassessed the traditional view that mammalian urinary bladder lacks ion transport mechanisms. Since the ratio of actual-to-nominal membrane area in folded epithelia is variable and hard to estimate, we normalized membrane properties to apical membrane capacitance rather than to nominal area (probably 1 muF approximately 1 cm2 actual area). A new mounting technique that virtually eliminates edge damage yielded resistances up to 78,000 omega muF for rabbit bladder, and resistances for amphibian skin and bladder much higher than those usually reported. This technique made it possible to observe a transport-related conductance pathway, and a close correlation between transepithelial conductance (G) and short-circuit current (Isc) in these tight epithelia. G and Isc were increased by mucosal (Na+) [Isc approximately 0 when (Na+) approximately 0], aldosterone, serosal (HCO-3) and high mucosal (H+); were decreased by amiloride, mucosal (Ca++), ouabain, metabolic inhibitors and serosal (H+); and were unaffected by (Cl-) and little affected by antidiuretic hormone (ADH). Physiological variation in the rabbits' dietary Na+ intake caused variations in bladder G and Isc similar to those caused by the expected in vivo changes in aldosterone levels. The relation between G and Isc was the same whether defined by diet changes, natural variation among individual rabbits, or most of the above agents. A method was developed for separately resolving conductances of junctions, basolateral cell membrane, and apical cell membrane from this G--Isc relation. Net Na+ flux equalled Isc. Net Cl- flux was zero on short circuit and equalled only 25% of net Na+ flux in open circuit. Bladder membrane fragments contained a Na+-K+-activated, ouabain-inhibited ATPase. The physiological significance of Na+ absorption against steep gradients in rabbit bladder may be to maintain kidney-generated ion gradients during bladder storage of urine, especially

  6. PLEKHA7 modulates epithelial tight junction barrier function

    PubMed Central

    Paschoud, Serge; Jond, Lionel; Guerrera, Diego; Citi, Sandra

    2014-01-01

    PLEKHA7 is a recently identified protein of the epithelial zonula adhaerens (ZA), and is part of a protein complex that stabilizes the ZA, by linking it to microtubules. Since the ZA is important in the assembly and disassembly of tight junctions (TJ), we asked whether PLEKHA7 is involved in modulating epithelial TJ barrier function. We generated clonal MDCK cell lines in which one of four different constructs of PLEKHA7 was inducibly expressed. All constructs were localized at junctions, but constructs lacking the C-terminal region were also distributed diffusely in the cytoplasm. Inducible expression of PLEKHA7 constructs did not affect the expression and localization of TJ proteins, the steady-state value of transepithelial resistance (TER), the development of TER during the calcium switch, and the flux of large molecules across confluent monolayers. In contrast, expression of three out of four constructs resulted both in enhanced recruitment of E-cadherin and associated proteins at the apical ZA and at lateral puncta adherentia (PA), a decreased TER at 18 h after assembly at normal calcium, and an attenuation in the fall in TER after extracellular calcium removal. This latter effect was inhibited when cells were treated with nocodazole. Immunoprecipitation analysis showed that PLEKHA7 forms a complex with the cytoplasmic TJ proteins ZO-1 and cingulin, and this association does not depend on the integrity of microtubules. These results suggest that PLEKHA7 modulates the dynamics of assembly and disassembly of the TJ barrier, through E-cadherin protein complex- and microtubule-dependent mechanisms. PMID:24843844

  7. Tightly Coupled Geodynamic Systems: Software, Implicit Solvers & Applications

    NASA Astrophysics Data System (ADS)

    May, D.; Le Pourhiet, L.; Brown, J.

    2011-12-01

    The generic term "multi-physics" is used to define physical processes which are described by a collection of partial differential equations, or "physics". Numerous processes in geodynamics fall into this category. For example, the evolution of viscous fluid flow and heat transport within the mantle (Stokes flow + energy conservation), the dynamics of melt migration (Stokes flow + Darcy flow + porosity evolution) and landscape evolution (Stokes + diffusion/advection over a surface). The development of software to numerically investigate processes that are described through the composition of different physics components are typically (a) designed for one particular set of physics and are never intended to be extended, or coupled to other processes (b) enforce that certain non-linearity's (or coupling) are explicitly removed from the system for reasons of computational efficiency, or due the lack of a robust non-linear solver (e.g. most models in the mantle convection community). We describe a software infrastructure which enables us to easily introduce new physics with minimal code modifications; tightly couple all physics without introducing splitting errors; exploit modern linear/non-linear solvers and permit the re-use of monolithic preconditioners for individual physics blocks (e.g. saddle point preconditioners for Stokes). Here we present a number of examples to illustrate the flexibility and importance of using this software infra-structure. Using the Stokes system as a prototype, we show results illustrating (i) visco-plastic shear banding experiments, (ii) how coupling Stokes flow with the evolution of the material coordinates can yield temporal stability in the free surface evolution and (iii) the discretisation error associated with decoupling Stokes equation from the heat transport equation in models of mantle convection with various rheologies.

  8. Tight Abo gas sands, east-central New Mexico

    SciTech Connect

    Broadhead, R.F.

    1983-03-01

    Red-bed sandstones of the Abo Formation (Lower Permian) currently produce natural gas from the Pecos Slope Abo field in northern Chaves County, New Mexico. The Pecos Slope Abo field is on the northwest shelf of the Permian basin. The tight-sand designation greatly stimulated drilling and over 250 wells have been drilled since field discovery in 1977. Because of low permeability, wells must be artificially fractured to obtain economic production. Initial production rises from a few tens of MCFGD before fracturing to an average of about 2200 MCFGD after fracturing. The lower granite wash interval is more than 800 ft (248 m) thick in some places and is composed of interbedded coarse-grained arkosic sandstones and arkosic conglomerates. The middle interval is about 100 ft (30 m) thick and conformably overlies the lower interval and the Hueco limestones. It is composed of calcareous, sparsely fossiliferous, argillaceous mudstone and minor fine-grained sandstone. The upper interval is about 600 ft (183 m) thick and is composed of interbedded mudstones and lenticular sandstones. It conformably overlies the middle interval and is disconformably overlain by the dolostones, anhydrites, and fine-grained sandstones of the Yeso Formation. Gas is produced from sandstones in the upper interval. The Abo wells tap a gas-filled natural fracture system. Mudstones seal the fractured sandstone reservoirs. Because fluvial-deltaic deposits extend almost 100 mi (161 km) north of present production, the area underlain by potential, fractured, Abo sandstone reservoirs is at least five times greater than the area which is currently productive.

  9. Pores in the epidermis: aquaporins and tight junctions.

    PubMed

    Brandner, J M

    2007-12-01

    Water homeostasis of the epidermis is important for the appearance and physical properties of the skin, as well as for water balance in the body. It depends on several factors, e.g. barrier quality, uptake of water into the epidermis, concentration of water-retaining humectants, and external humidity. Aquaporins (AQPs) are pores in the plasmamembranes of cells. Monomeric AQPs form barrel-like structures that are primarily water selective, some AQPs also transport glycerol and possibly other small solutes. In the epidermis, AQP3 is the predominant AQP. It is localized mainly in basal but also in suprabasal layers of the epidermis and is permeable for water as well as for glycerol, a humectant. Mice deficient in AQP3 exhibit reduced stratum corneum (SC) hydration and impaired SC barrier recovery after SC removal. In skin diseases associated with elevated transepidermal water loss (TEWL) and reduced SC hydration, altered expression of AQP3 was shown. Tight junctions (TJ) are cell-cell junctions, which play a central role in sealing the intercellular space of cell sheets and thereby establishing a paracellular barrier. Within the TJ, pores are postulated to exist, which allow the controlled diffusion of water and solutes via the paracellular pathway. In the epidermis, TJ structures were demonstrated in the stratum granulosum whereas TJ proteins were found in all viable layers. Mice which overexpress or are deficient of key-proteins of TJ die soon after birth because of a tremendous TEWL. In various skin diseases that are accompanied by elevated TEWL and reduced skin hydration, staining patterns of TJ proteins are altered. This review will summarize our current knowledge of the involvement of AQPs and TJ in the water homeostasis of the epidermis. PMID:18489380

  10. Naturally fractured tight gas reservoir detection optimization. Final report

    SciTech Connect

    1997-11-19

    This DOE-funded research into seismic detection of natural fractures is one of six projects within the DOE`s Detection and Analysis of Naturally Fractured Gas Reservoirs Program, a multidisciplinary research initiative to develop technology for prediction, detection, and mapping of naturally fractured gas reservoirs. The demonstration of successful seismic techniques to locate subsurface zones of high fracture density and to guide drilling orientation for enhanced fracture permeability will enable better returns on investments in the development of the vast gas reserves held in tight formations beneath the Rocky Mountains. The seismic techniques used in this project were designed to capture the azimuthal anisotropy within the seismic response. This seismic anisotropy is the result of the symmetry in the rock fabric created by aligned fractures and/or unequal horizontal stresses. These results may be compared and related to other lines of evidence to provide cross-validation. The authors undertook investigations along the following lines: Characterization of the seismic anisotropy in three-dimensional, P-wave seismic data; Characterization of the seismic anisotropy in a nine-component (P- and S-sources, three-component receivers) vertical seismic profile; Characterization of the seismic anisotropy in three-dimensional, P-to-S converted wave seismic data (P-wave source, three-component receivers); and Description of geological and reservoir-engineering data that corroborate the anisotropy: natural fractures observed at the target level and at the surface, estimation of the maximum horizontal stress in situ, and examination of the flow characteristics of the reservoir.

  11. Tight Chk1 Levels Control Replication Cluster Activation in Xenopus

    PubMed Central

    Wiggins, Jennifer M.; Barbosa, Pedro; Libeau, Pierre; Priam, Pierre; Narassimprakash, Hemalatha; Grodzenski, Xenia; Marheineke, Kathrin

    2015-01-01

    DNA replication in higher eukaryotes initiates at thousands of origins according to a spatio-temporal program. The ATR/Chk1 dependent replication checkpoint inhibits the activation of later firing origins. In the Xenopus in vitro system initiations are not sequence dependent and 2-5 origins are grouped in clusters that fire at different times despite a very short S phase. We have shown that the temporal program is stochastic at the level of single origins and replication clusters. It is unclear how the replication checkpoint inhibits late origins but permits origin activation in early clusters. Here, we analyze the role of Chk1 in the replication program in sperm nuclei replicating in Xenopus egg extracts by a combination of experimental and modelling approaches. After Chk1 inhibition or immunodepletion, we observed an increase of the replication extent and fork density in the presence or absence of external stress. However, overexpression of Chk1 in the absence of external replication stress inhibited DNA replication by decreasing fork densities due to lower Cdk2 kinase activity. Thus, Chk1 levels need to be tightly controlled in order to properly regulate the replication program even during normal S phase. DNA combing experiments showed that Chk1 inhibits origins outside, but not inside, already active clusters. Numerical simulations of initiation frequencies in the absence and presence of Chk1 activity are consistent with a global inhibition of origins by Chk1 at the level of clusters but need to be combined with a local repression of Chk1 action close to activated origins to fit our data. PMID:26046346

  12. Tight junctions in Hailey-Hailey and Darier's diseases

    PubMed Central

    Raiko, Laura; Leinonen, Pekka; Hägg, Päivi M.; Peltonen, Juha; Oikarinen, Aarne; Peltonen, Sirkku

    2009-01-01

    Hailey-Hailey disease (HHD) and Darier's disease (DD) are caused by mutations in Ca2+-ATPases with the end result of desmosomal disruption and suprabasal acantholysis. Tight junctions (TJ) are located in the granular cell layer in normal skin and contribute to the epidermal barrier. Aberrations in the epidermal differentiation, such as in psoriasis, have been shown to lead to changes in the expression of TJ components. Our aim was to elucidate the expression and dynamics of the TJ proteins during the disruption of desmosomes in HHD and DD lesions. Indirect immunofluorescence and avidin-biotin labeling for TJ, desmosomal and adherens junction proteins, and subsequent analyses with the confocal laser scanning microscope were carried out on 14 HHD and 14 DD skin samples. Transepidermal water loss (TEWL) was measured in normal and lesional epidermis of nine HHD and eight DD patients to evaluate the function of the epidermal barrier in HHD and DD skin. The localization of TJ proteins claudin-1, claudin-4, ZO-1, and occludin in perilesional HHD and DD epidermis was similar to that previously described in normal skin. In HHD lesions the tissue distribution of ZO-1 expanded to the acantholytic spinous cells. In agreement with previous findings, desmoplakin was localized intracellularly. In contrast claudin-1 and ZO-1 persisted in the cell-cell contact sites of acantholytic cells. TEWL was increased in the lesional skin. The current results suggest that TJ components follow different dynamics in acantholysis of HHD and DD compared to desmosomal and adherens junction proteins. PMID:25386233

  13. Conservative tightly-coupled simulations of stochastic multiscale systems

    NASA Astrophysics Data System (ADS)

    Taverniers, Søren; Pigarov, Alexander Y.; Tartakovsky, Daniel M.

    2016-05-01

    Multiphysics problems often involve components whose macroscopic dynamics is driven by microscopic random fluctuations. The fidelity of simulations of such systems depends on their ability to propagate these random fluctuations throughout a computational domain, including subdomains represented by deterministic solvers. When the constituent processes take place in nonoverlapping subdomains, system behavior can be modeled via a domain-decomposition approach that couples separate components at the interfaces between these subdomains. Its coupling algorithm has to maintain a stable and efficient numerical time integration even at high noise strength. We propose a conservative domain-decomposition algorithm in which tight coupling is achieved by employing either Picard's or Newton's iterative method. Coupled diffusion equations, one of which has a Gaussian white-noise source term, provide a computational testbed for analysis of these two coupling strategies. Fully-converged ("implicit") coupling with Newton's method typically outperforms its Picard counterpart, especially at high noise levels. This is because the number of Newton iterations scales linearly with the amplitude of the Gaussian noise, while the number of Picard iterations can scale superlinearly. At large time intervals between two subsequent inter-solver communications, the solution error for single-iteration ("explicit") Picard's coupling can be several orders of magnitude higher than that for implicit coupling. Increasing the explicit coupling's communication frequency reduces this difference, but the resulting increase in computational cost can make it less efficient than implicit coupling at similar levels of solution error, depending on the communication frequency of the latter and the noise strength. This trend carries over into higher dimensions, although at high noise strength explicit coupling may be the only computationally viable option.

  14. Spark Plug Defects and Tests

    NASA Technical Reports Server (NTRS)

    Silsbee, F B; Loeb, L B; Sawyer, L G; Fonseca, E L; Dickinson, H C; Agnew, P G

    1920-01-01

    The successful operation of the spark plug depends to a large extent on the gas tightness of the plug. Part 1 of this report describes the method used for measuring the gas tightness of aviation spark plugs. Part 2 describes the methods used in testing the electrical conductivity of the insulation material when hot. Part 3 describes the testing of the cold dielectric strength of the insulation material, the resistance to mechanical shock, and the final engine test.

  15. Gas-Phase Structures of Ketene and Acetic Acid from Acetic Anhydride Using Very-High-Temperature Gas Electron Diffraction.

    PubMed

    Atkinson, Sandra J; Noble-Eddy, Robert; Masters, Sarah L

    2016-03-31

    The gas-phase molecular structure of ketene has been determined using samples generated by the pyrolysis of acetic anhydride (giving acetic acid and ketene), using one permutation of the very-high-temperature (VHT) inlet nozzle system designed and constructed for the gas electron diffraction (GED) apparatus based at the University of Canterbury. The gas-phase structures of acetic anhydride, acetic acid, and ketene are presented and compared to previous electron diffraction and microwave spectroscopy data to show improvements in data extraction and manipulation with current methods. Acetic anhydride was modeled with two conformers, rather than a complex dynamic model as in the previous study, to allow for inclusion of multiple pyrolysis products. The redetermined gas-phase structure of acetic anhydride (obtained using the structure analysis restrained by ab initio calculations for electron diffraction method) was compared to that from the original study, providing an improvement on the description of the low vibrational torsions compared to the dynamic model. Parameters for ketene and acetic acid (both generated by the pyrolysis of acetic anhydride) were also refined with higher accuracy than previously reported in GED studies, with structural parameter comparisons being made to prior experimental and theoretical studies. PMID:26916368

  16. An energy-conserving pyruvate-to-acetate pathway in Entamoeba histolytica. Pyruvate synthase and a new acetate thiokinase.

    PubMed

    Reeves, R E; Warren, L G; Susskind, B; Lo, H S

    1977-01-25

    Under anaerobic conditions, cells of Entamoeba histolytica grown with bacteria produce H2 and acetate while cells grown axenically produce neither. Aerobically, acetate is produced and O2 is consumed by amebae from either type of cells. Centrifuged extracts, 2.4 x 106 x g x min, from both types of cells contain pyruvate synthase (EC 1.2.7.1) and an acetate thiokinase which, together, form a system capable of converting pyruvate to acetate. Pyruvate synthase catalyzes the reaction: pyruvate + CoA leads to CO2 + acetyl-CoA + 2E. Electron acceptors which function with this enzyme are FAD, FMN, riboflavin, ferredoxin, and methyl viologen, but not NAD or NADP. The amebal acetate thiokinase catalyzes the reaction acetyl-CoA + ADP + Pi leads to acetate + ATP + CoA. For this apparently new enzyme we suggest the trivial name acetyl-CoA-synthetase (ADP-forming). Extracts from axenic amebae do not contain hydrogenase, but extracts from cells grown with bacteria do. It is postulated that in bacteria-grown amebae electrons generated at the pyruvate synthase step are utilized anaerobically to produce H2 via the hydrogenase and that the acetyl-CoA is converted to acetate in an energy-conserving step catalyzed by amebal acetyl-CoA synthetase. Aerobically, cells grown under either regimen may utilize the energy-conserving pyruvate-to-acetate pathway since O2 then serves as the ultimate electron acceptor. PMID:13076

  17. Biological Function of Acetic Acid-Improvement in Obesity and Glucose Tolerance by Acetic Acid in Type 2 Diabetic Rats.

    PubMed

    Yamashita, Hiromi

    2016-07-29

    Fatty acids derived from adipose tissue are oxidized by β-oxidation to form ketone bodies as final products under the starving condition. Previously, we found that free acetic acid was formed concomitantly with the production of ketone bodies in isolated rat liver perfusion, and mitochondrial acetyl CoA hydrolase was appeared to be involved with the acetic acid production. It was revealed that acetic acid was formed as a final product of enhanced β-oxidation of fatty acids and utilized as a fuel in extrahepatic tissues under the starving condition. Under the fed condition, β-oxidation is suppressed and acetic acid production is decreased. When acetic acid was taken daily by obesity-linked type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats under the fed condition, it protected OLETF rats against obesity. Furthermore, acetic acid contributed to protect from the accumulation of lipid in the liver as well as abdominal fat in OLETF rats. Transcripts of lipogenic genes in the liver were decreased, while transcripts of myoglobin and Glut4 genes in abdominal muscles were increased in the acetic acid-administered OLETF rats. It is indicated that exogenously administered acetic acid would have effects on lipid metabolism in both the liver and the skeletal muscles, and have function that works against obesity and obesity-linked type 2 diabetes. PMID:26176799

  18. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    NASA Technical Reports Server (NTRS)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

  19. Oxidation of indole-3-acetic acid and oxindole-3-acetic acid to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glucopyranoside in Zea mays seedlings

    NASA Technical Reports Server (NTRS)

    Nonhebel, H. M.; Bandurski, R. S.

    1984-01-01

    Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.

  20. Recovery of DNA from latent fingerprint tape lifts archived against matte acetate.

    PubMed

    Steadman, Shelly A; Hoofer, Steven R; Geering, Sarah C; King, Stephanie; Bennett, Marc A

    2015-05-01

    This study was driven by court order to examine methods to remove, extract, and STR-type potential DNA entrapped between latent fingerprint lifting tape and matte acetate that was collected from a 1977 crime scene. Results indicate that recovery of appreciable quantities of DNA is more challenging once adhesive is attached to matte acetate cards and even more difficult when fixed following black powder enhancement. STR amplification of extracts from entrapped fingermarks collected following the dusting/lifting procedure did not produce robust profiles, and extraneous peaks not expressed by print donors were detected for some samples. A hearing was set to argue whether there was DNA remaining to be tested, and if so, whether that DNA could be exculpatory in this postconviction matter. The studies herein provided the basis for the court's decision to not require the testing. PMID:25702951

  1. Micelles Protect and Concentrate Activated Acetic Acid

    NASA Astrophysics Data System (ADS)

    Todd, Zoe; House, C.

    2014-01-01

    As more and more exoplanets are discovered and the habitability of such planets is considered, one can turn to searching for the origin of life on Earth in order to better understand what makes a habitable planet. Activated acetic acid, or methyl thioacetate, has been proposed to be central to the origin of life on Earth, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s^-1; 100°C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, we also observed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. We found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid micelles. Thus, the hydrophobic regions of prebiotic micelles and early cell membranes could have offered a refuge for this energetic molecule increasing its lifetime in close proximity to the reactions for which it would be needed. Methyl thioacetate could thus be important for the origin of life on Earth and perhaps for better understanding the potential habitability of other planets.

  2. Dexamethasone acetate encapsulation into Trojan particles.

    PubMed

    Gómez-Gaete, Carolina; Fattal, Elias; Silva, Lídia; Besnard, Madeleine; Tsapis, Nicolas

    2008-05-22

    We have combined the therapeutic potential of nanoparticles systems with the ease of manipulation of microparticles by developing a hybrid vector named Trojan particles. We aim to use this new delivery vehicle for intravitreal administration of dexamethasone. Initialy, dexamethasone acetate (DXA) encapsulation into biodegradable poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles was optimized. Then, Trojan particles were formulated by spray drying 1,2-Dipalmitoyl-sn-Glycero-3-Phosphocholine (DPPC), hyaluronic acid (HA) and different concentrations of nanoparticle suspensions. The effect of nanoparticles concentration on Trojan particle physical characteristics was investigated as well as the effect of the spray drying process on nanoparticles size. Finally, DXA in vitro release from nanoparticles and Trojan particles was evaluated under sink condition. SEM and confocal microscopy show that most of Trojan particles are spherical, hollow and possess an irregular surface due to the presence of nanoparticles. Neither Trojan particle tap density nor size distribution are significantly modified as a function of nanoparticles concentration. The mean nanoparticles size increase significantly after spray drying. Finally, the in vitro release of DXA shows that the excipient matrix provides protection to encapsulated nanoparticles by slowing drug release. PMID:18374442

  3. Eslicarbazepine acetate for partial-onset seizures.

    PubMed

    Rauchenzauner, Markus; Luef, Gerhard

    2011-12-01

    Eslicarbazepine acetate (ESL), a new voltage-gated sodium channel blocker that is chemically related to carbamazepine and partially metabolized to oxcarbazepine, has attracted attention as results of previous Phase II and III studies demonstrated and confirmed efficacy and tolerability of ESL 800 and 1200 mg once daily as add-on therapy for adult patients with drug-resistant partial-onset seizures. In children, efficacy data point towards a dose-dependent decrease in seizure frequency and tolerability analyses showed a low incidence of mild drug-related adverse effects at 5 and 15 mg/kg/day. The most frequently reported adverse effects were dizziness, somnolence, headache, diplopia, nausea and vomiting. The convenience of once-daily dosing and a short/simple titration regimen in combination with a comparative efficacy and tolerability profile might promote ESL as a valid alternative to the current adjunctive antiepileptic drug therapy armamentarium for drug-resistant partial seizures in adults. Since clinical trials in children and adolescents on ESL efficacy and safety are ongoing and data already published are far from conclusive, the therapeutic value of ESL in this special population has to be established in the near future. PMID:22091592

  4. Pharmacokinetics and drug interactions of eslicarbazepine acetate.

    PubMed

    Bialer, Meir; Soares-da-Silva, Patricio

    2012-06-01

    Eslicarbazepine acetate (ESL) is a novel once-daily antiepileptic drug (AED) approved in Europe since 2009 that was found to be efficacious and well tolerated in a phase III clinical program in adult patients with partial onset seizures previously not controlled with treatment with one to three AEDs, including carbamazepine (CBZ). ESL shares with CBZ and oxcarbazepine (OXC) the dibenzazepine nucleus bearing the 5-carboxamide substitute, but is structurally different at the 10,11 position. This molecular variation results in differences in metabolism, preventing the formation of toxic epoxide metabolites such as carbamazepine-10,11-epoxide. Unlike OXC, which is metabolized to both eslicarbazepine and (R)-licarbazepine, ESL is extensively converted to eslicarbazepine. The systemic exposure to eslicarbazepine after ESL oral administration is approximately 94% of the parent dose, with minimal exposure to (R)-licarbazepine and OXC. After ESL oral administration, the effective half-life (t(1/2,eff) ) of eslicarbazepine was 20-24 h, which is approximately two times longer than its terminal half-life (t(1/2)). At clinically relevant doses (400-1,600 mg/day) ESL has linear pharmacokinetics (PK) with no effects of gender or moderate liver impairment. However, because eslicarbazepine is eliminated primarily (66%) by renal excretion, dose adjustment is recommended for patients with renal impairment. Eslicarbazepine clearance is induced by phenobarbital, phenytoin, and CBZ and it dose-dependently decreases plasma exposure of oral contraceptive and simvastatin. PMID:22612290

  5. Biodegradable cellulose acetate nanofiber fabrication via electrospinning.

    PubMed

    Christoforou, Theopisti; Doumanidis, Charalabos

    2010-09-01

    Nanofiber manufacturing is one of the key advancements in nanotechnology today. Over the past few years, there has been a tremendous growth of research activities to explore electrospinning for nanofiber formation from a rich variety of materials. This quite simple and cost effective process operates on the principle that the solution is extracted under the action of a high electric field. Once the voltage is sufficiently high, a charged jet is ejected following a complicated looping trajectory. During its travel, the solvent evaporates leaving behind randomly oriented nanofibers accumulated on the collector. The combination of their nanoscale dimensionality, high surface area, porosity, flexibility and superior strength makes the electrospun fibers suitable for several value-added applications, such as filters, protecting clothes, high performance structures and biomedical devices. In this study biodegradable cellulose acetate (CA) nanofibrous membranes were produced using electrospinning. The device utilized consisted of a syringe equipped with a metal needle, a microdialysis pump, a high voltage supply and a collector. The morphology of the yielded fibers was determined using SEM. The effect of various parameters, including electric field strength, tip-to-collector distance, solution feed rate and composition on the morphological features of the electrospun fibers was examined. The optimum operating conditions for the production of uniform, non-beaded fibers with submicron diameter were also explored. The biodegradable CA nanofiber membranes are suitable as tissue engineering scaffolds and as reinforcements of biopolymer matrix composites in foils by ultrasonic welding methods. PMID:21133179

  6. Quantitative Structure of an Acetate Dye Molecule Analogue at the TiO2–Acetic Acid Interface

    PubMed Central

    2016-01-01

    The positions of atoms in and around acetate molecules at the rutile TiO2(110) interface with 0.1 M acetic acid have been determined with a precision of ±0.05 Å. Acetate is used as a surrogate for the carboxylate groups typically employed to anchor monocarboxylate dye molecules to TiO2 in dye-sensitized solar cells (DSSC). Structural analysis reveals small domains of ordered (2 × 1) acetate molecules, with substrate atoms closer to their bulk terminated positions compared to the clean UHV surface. Acetate is found in a bidentate bridge position, binding through both oxygen atoms to two 5-fold titanium atoms such that the molecular plane is along the [001] azimuth. Density functional theory calculations provide adsorption geometries in excellent agreement with experiment. The availability of these structural data will improve the accuracy of charge transport models for DSSC. PMID:27110318

  7. Nomegestrol acetate: pharmacology, safety profile and therapeutic efficacy.

    PubMed

    Lello, Stefano

    2010-03-26

    This review summarizes the pharmacology, safety and clinical efficacy of nomegestrol acetate, based on the available published literature, and assesses the pharmacological characteristics that underlie a role in different gynaecological disorders and hormone replacement therapy (HRT), and a potential role in combination estrogen/progestogen oral contraception. Nomegestrol acetate is a potent, orally active progestogen with a favourable tolerability profile and neutral metabolic characteristics. Unlike the majority of older progestogens, which were 19-nortestosterone derivatives synthesized primarily for their antigonadotropic activity as a component of hormonal contraception in combination with an estrogen, nomegestrol acetate is a 19-norprogesterone derivative designed to bind specifically to the progesterone receptor, and is relatively lacking in affinity for other steroid receptors. Nomegestrol acetate exerts strong antiestrogenic effects at the level of the endometrium and has potent antigonadotropic activity, but without any residual androgenic or glucocorticoid properties. At a dosage of 1.25 mg/day, nomegestrol acetate inhibits ovulation while permitting follicle growth, whereas at dosages of 2.5 or 5 mg/day, both ovulation and follicle development are suppressed. The antigonadotropic action of nomegestrol acetate is mediated, like other progestins, at the hypothalamic and pituitary level. Moreover, nomegestrol acetate has partial antiandrogenic activity. Absorption of nomegestrol acetate is rapid after oral administration, reaching a peak serum concentration within 4 hours, with a terminal half-life of approximately 50 hours. Nomegestrol acetate has been used successfully for the treatment of some gynaecological disorders (menstrual disturbances, dysmenorrhoea, premenstrual syndrome) and as a component of HRT in combination with estradiol for the relief of menopausal symptoms; it has been approved in Europe as monotherapy for the treatment of the menopausal

  8. Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor.

    PubMed

    Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

    2016-02-01

    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation. PMID:26253254

  9. AMP-activated protein kinase regulates the assembly of epithelial tight junctions.

    PubMed

    Zhang, Li; Li, Ji; Young, Lawrence H; Caplan, Michael J

    2006-11-14

    AMP activated protein kinase (AMPK), a sensor of cellular energy status in all eukaryotic cells, is activated by LKB1-dependent phosphorylation. Recent studies indicate that activated LKB1 induces polarity in epithelial cells and that this polarization is accompanied by the formation of tight junction structures. We wished to determine whether AMPK also contributes to the assembly of tight junctions in the epithelial cell polarization process. We found that AMPK is activated during calcium-induced tight junction assembly. Activation of AMPK by 5-aminoimidazole-4-carboxamide ribonucleoside facilitates tight junction assembly under conditions of normal extracellular Ca2+ concentrations and initiates tight junction assembly in the absence of Ca2+ as revealed by the relocation of zonula occludens 1, the establishment of transepithelial electrical resistance, and the paracellular flux assay. Expression of a dominant negative AMPK construct inhibits tight junction assembly in MDCK cells, and this defect in tight junction assembly can be partially ameliorated by rapamycin. These results suggest that AMPK plays a role in the regulation of tight junction assembly. PMID:17088526

  10. Exploring a Transformative Orientation to Sustainability in Universities: A Question of Loose and Tight Framings

    ERIC Educational Resources Information Center

    Scott, William A. H.

    2015-01-01

    This review essay examines three new books on higher education and sustainability. It explores a number of the issues raised in the books, in particular, the meaning of a transformative orientation towards sustainability. The idea of loose and tight conceptual framings of sustainability is employed. A tight framing is where an institution embodies…

  11. Correlation of shoulder and elbow injuries with muscle tightness, core stability, and balance by longitudinal measurements in junior high school baseball players.

    PubMed

    Endo, Yasuhiro; Sakamoto, Masaaki

    2014-05-01

    [Purpose] The present study longitudinally investigated injury occurrences and the risk factors for muscle tightness, core stability, and dynamic standing balance among junior high school student baseball players. [Subjects] Thirty-nine male students, belonging to baseball clubs at 2 junior high schools, participated in this study. [Methods] Study measurements were obtained twice, once in the early stage of the baseball season (March) and once at the end of the season (July). All subjects underwent muscle tightness testing, the Star Excursion Balance Test (SEBT), and trunk endurance testing during each measurement session. [Results] Fifteen players experienced episodes of elbow or shoulder pain while throwing. Players in the pain group demonstrated a significant increase in the tightness of their shoulder internal rotators, axis-leg quadriceps, and axis-leg hamstrings. There was no clear evidence of differences of changes in core stability and dynamic standing balance between the groups. [Conclusion] The results of this study suggest that lower extremity muscle tightness early in a season and the subsequent decline in the flexibility of the axis-leg quadriceps and hamstrings during the season may be due to an increased upper extremity load while throwing, thus producing shoulder and elbow pain. PMID:24926133

  12. Kinetics of cytochrome P450 2E1-catalyzed oxidation of ethanol to acetic acid via acetaldehyde.

    PubMed

    Bell-Parikh, L C; Guengerich, F P

    1999-08-20

    The P450 2E1-catalyzed oxidation of ethanol to acetaldehyde is characterized by a kinetic deuterium isotope effect that increases K(m) with no effect on k(cat), and rate-limiting product release has been proposed to account for the lack of an isotope effect on k(cat) (Bell, L. C., and Guengerich, F. P. (1997) J. Biol. Chem. 272, 29643-29651). Acetaldehyde is also a substrate for P450 2E1 oxidation to acetic acid, and k(cat)/K(m) for this reaction is at least 1 order of magnitude greater than that for ethanol oxidation to acetaldehyde. Acetic acid accounts for 90% of the products generated from ethanol in a 10-min reaction, and the contribution of this second oxidation has been overlooked in many previous studies. The noncompetitive intermolecular kinetic hydrogen isotope effects on acetaldehyde oxidation to acetic acid ((H)(k(cat)/K(m))/(D)(k(cat)/K(m)) = 4.5, and (D)k(cat) = 1.5) are comparable with the isotope effects typically observed for ethanol oxidation to acetaldehyde, and k(cat) is similar for both reactions, suggesting a possible common catalytic mechanism. Rapid quench kinetic experiments indicate that acetic acid is formed rapidly from added acetaldehyde (approximately 450 min(-1)) with burst kinetics. Pulse-chase experiments reveal that, at a subsaturating concentration of ethanol, approximately 90% of the acetaldehyde intermediate is directly converted to acetic acid without dissociation from the enzyme active site. Competition experiments suggest that P450 2E1 binds acetic acid and acetaldehyde with relatively high K(d) values, which preclude simple tight binding as an explanation for rate-limiting product release. The existence of a rate-determining step between product formation and release is postulated. Also proposed is a conformational change in P450 2E1 occurring during the course of oxidation and the discrimination of P450 2E1 between acetaldehyde and its hydrated form, the gem-diol. This multistep P450 reaction is characterized by kinetic

  13. Computerized image analysis for acetic acid induced intraepithelial lesions

    NASA Astrophysics Data System (ADS)

    Li, Wenjing; Ferris, Daron G.; Lieberman, Rich W.

    2008-03-01

    Cervical Intraepithelial Neoplasia (CIN) exhibits certain morphologic features that can be identified during a visual inspection exam. Immature and dysphasic cervical squamous epithelium turns white after application of acetic acid during the exam. The whitening process occurs visually over several minutes and subjectively discriminates between dysphasic and normal tissue. Digital imaging technologies allow us to assist the physician analyzing the acetic acid induced lesions (acetowhite region) in a fully automatic way. This paper reports a study designed to measure multiple parameters of the acetowhitening process from two images captured with a digital colposcope. One image is captured before the acetic acid application, and the other is captured after the acetic acid application. The spatial change of the acetowhitening is extracted using color and texture information in the post acetic acid image; the temporal change is extracted from the intensity and color changes between the post acetic acid and pre acetic acid images with an automatic alignment. The imaging and data analysis system has been evaluated with a total of 99 human subjects and demonstrate its potential to screening underserved women where access to skilled colposcopists is limited.

  14. Methane Production and Syntrophic Acetate Oxidation in the Florida Everglades

    NASA Astrophysics Data System (ADS)

    Holmes, M. E.; Chanton, J.; Bae, H.; Ogram, A.

    2012-12-01

    Methane production pathways in the Florida Everglades are influenced by factors such as nutrient levels, H2 concentrations, and temperature. Syntrophic acetate oxidizers can outcompete methanogens for acetate when conditions are right (high temperatures and low H2). During syntrophic acetate oxidation (SAO), which becomes more exergonic with increasing temperature, acetate is oxidized to carbon dioxide and H2, which can be utilized to produce methane via CO2 reduction. Everglades soil from along a nutrient gradient was incubated at 25°C and 45°C. The shift to the CO2 reduction pathway for methane formation that would be expected in high temperature incubations due to SAO should result in a decrease in δ13C-CH4 and increase in δ2H-CH4. Instead, we observed higher δ13C and lower δ2H in the methane produced in high temperature incubations. The higher than expected δ13C may be partly explained by lower kinetic isotope effects caused by temperature. Coupling between the syntrophic acetate oxidizers and the CO2 reducers, whereby isotopically light hydrogen from acetate is used in methane formation could lower δ2H-CH4. Separate experiments using 13C-labelled acetate revealed that potential SAO activity is low in soils collected from the Everglades.

  15. Perspectives for the biotechnological production of ethyl acetate by yeasts.

    PubMed

    Löser, Christian; Urit, Thanet; Bley, Thomas

    2014-06-01

    Ethyl acetate is an environmentally friendly solvent with many industrial applications. The production of ethyl acetate currently proceeds by energy-intensive petrochemical processes which are based on natural gas and crude oil without exception. Microbial synthesis of ethyl acetate could become an interesting alternative. The formation of esters as aroma compounds in food has been repeatedly reviewed, but a survey which deals with microbial synthesis of ethyl acetate as a bulk product is missing. The ability of yeasts for producing larger amounts of this ester is known for a long time. In the past, this potential was mainly of scientific interest, but in the future, it could be applied to large-scale ester production from renewable raw materials. Pichia anomala, Candida utilis, and Kluyveromyces marxianus are yeasts which convert sugar into ethyl acetate with a high yield where the latter is the most promising one. Special attention was paid to the mechanism of ester synthesis including regulatory aspects and to the maximum and expectable yield. Synthesis of much ethyl acetate requires oxygen which is usually supplied by aeration. Ethyl acetate is highly volatile so that aeration results in its phase transfer and stripping. This stripping process cannot be avoided but requires adequate handling during experimentation and offers a chance for a cost-efficient process-integrated recovery of the synthesized ester. PMID:24788328

  16. The Effects of Acetate Buffer Concentration on Lysozyme Solubility

    NASA Technical Reports Server (NTRS)

    Forsythe, Elizabeth L.; Pusey, Marc L.

    1996-01-01

    The micro-solubility column technique was employed to systematically investigate the effects of buffer concentration on tetragonal lysozyme solubility. While keeping the NaCl concentrations constant at 2%, 3%, 4%, 5% and 7%, and the pH at 4.0, we have studied the solubility of tetragonal lysozyme over an acetate buffer concentration range of 0.01M to 0.5M as a function of temperature. The lysozyme solubility decreased with increasing acetate concentration from 0.01M to 0.1M. This decrease may simply be due to the net increase in solvent ionic strength. Increasing the acetate concentration beyond 0.1M resulted in an increase in the lysozyme solubility, which reached a peak at - 0.3M acetate concentration. This increase was believed to be due to the increased binding of acetate to the anionic binding sites of lysozyme, preventing their occupation by chloride. In keeping with the previously observed reversal of the Hoffmeister series for effectiveness of anions in crystallizing lysozyme, acetate would be a less effective precipitant than chloride. Further increasing the acetate concentration beyond 0.3M resulted in a subsequent gradual decrease in the lysozyme solubility at all NaCl concentrations.

  17. Biochemical and biophysical analyses of tight junction permeability made of claudin-16 and claudin-19 dimerization

    PubMed Central

    Gong, Yongfeng; Renigunta, Vijayaram; Zhou, Yi; Sunq, Abby; Wang, Jinzhi; Yang, Jing; Renigunta, Aparna; Baker, Lane A.; Hou, Jianghui

    2015-01-01

    The molecular nature of tight junction architecture and permeability is a long-standing mystery. Here, by comprehensive biochemical, biophysical, genetic, and electron microscopic analyses of claudin-16 and -19 interactions—two claudins that play key polygenic roles in fatal human renal disease, FHHNC—we found that 1) claudin-16 and -19 form a stable dimer through cis association of transmembrane domains 3 and 4; 2) mutations disrupting the claudin-16 and -19 cis interaction increase tight junction ultrastructural complexity but reduce tight junction permeability; and 3) no claudin hemichannel or heterotypic channel made of claudin-16 and -19 trans interaction can exist. These principles can be used to artificially alter tight junction permeabilities in various epithelia by manipulating selective claudin interactions. Our study also emphasizes the use of a novel recording approach based on scanning ion conductance microscopy to resolve tight junction permeabilities with submicrometer precision. PMID:26446843

  18. Across-Time Change and Variation in Cultural Tightness-Looseness.

    PubMed

    Mandel, Anne; Realo, Anu

    2015-01-01

    Cultural tightness-looseness, a dimension which describes the strength, multitude, and clarity of social norms in a culture, has proved significant in explaining differences between cultures. Although several studies have compared different cultures on this domain, this study is the first that targets both within-country differences and across-time variation in tightness-looseness. Using data from two nationally representative samples of Estonians, we found that the general tightness level had changed over a period of 10 years but the effect size of the change was small. A significant within country variance in 2002 had disappeared by 2012. Our results suggest that tightness-looseness, similarly to cultural value orientations, is a relatively stable and robust characteristic of culture-that is, change indeed takes place, but slowly. Future studies about across-time change and within-country variance in tightness-looseness should target more culturally diverse and socially divided societies. PMID:26683813

  19. Across-Time Change and Variation in Cultural Tightness-Looseness

    PubMed Central

    Mandel, Anne; Realo, Anu

    2015-01-01

    Cultural tightness-looseness, a dimension which describes the strength, multitude, and clarity of social norms in a culture, has proved significant in explaining differences between cultures. Although several studies have compared different cultures on this domain, this study is the first that targets both within-country differences and across-time variation in tightness-looseness. Using data from two nationally representative samples of Estonians, we found that the general tightness level had changed over a period of 10 years but the effect size of the change was small. A significant within country variance in 2002 had disappeared by 2012. Our results suggest that tightness-looseness, similarly to cultural value orientations, is a relatively stable and robust characteristic of culture–that is, change indeed takes place, but slowly. Future studies about across-time change and within-country variance in tightness-looseness should target more culturally diverse and socially divided societies. PMID:26683813

  20. Transferable tight-binding model for strained group IV and III-V materials and heterostructures

    NASA Astrophysics Data System (ADS)

    Tan, Yaohua; Povolotskyi, Michael; Kubis, Tillmann; Boykin, Timothy B.; Klimeck, Gerhard

    2016-07-01

    It is critical to capture the effect due to strain and material interface for device level transistor modeling. We introduce a transferable s p3d5s* tight-binding model with nearest-neighbor interactions for arbitrarily strained group IV and III-V materials. The tight-binding model is parametrized with respect to hybrid functional (HSE06) calculations for varieties of strained systems. The tight-binding calculations of ultrasmall superlattices formed by group IV and group III-V materials show good agreement with the corresponding HSE06 calculations. The application of the tight-binding model to superlattices demonstrates that the transferable tight-binding model with nearest-neighbor interactions can be obtained for group IV and III-V materials.

  1. Methanogenic archaea and sulfate reducing bacteria co-cultured on acetate: teamwork or coexistence?

    PubMed Central

    Ozuolmez, Derya; Na, Hyunsoo; Lever, Mark A.; Kjeldsen, Kasper U.; Jørgensen, Bo B.; Plugge, Caroline M.

    2015-01-01

    Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and the interactions between both groups. We tested interspecies hydrogen transfer and coexistence between marine methanogens and sulfate reducers using mixed pure cultures of two types of microorganisms. First, Desulfovibrio vulgaris subsp. vulgaris (DSM 1744), a hydrogenotrophic sulfate reducer, was cocultured together with the obligate aceticlastic methanogen Methanosaeta concilii using acetate as carbon and energy source. Next, Methanococcus maripaludis S2, an obligate H2- and formate-utilizing methanogen, was used as a partner organism to M. concilii in the presence of acetate. Finally, we performed a coexistence experiment between M. concilii and an acetotrophic sulfate reducer Desulfobacter latus AcSR2. Our results showed that D. vulgaris was able to reduce sulfate and grow from hydrogen leaked by M. concilii. In the other coculture, M. maripaludis was sustained by hydrogen leaked by M. concilii as revealed by qPCR. The growth of the two aceticlastic microbes indicated co-existence rather than competition. Altogether, our results indicate that H2 leaking from M. concilii could be used by efficient H2-scavengers. This metabolic trait, revealed from coculture studies, brings new insight to the metabolic flexibility of methanogens and sulfate reducers residing in marine environments in response to changing environmental conditions and community compositions. Using dedicated physiological studies we were able to unravel the occurrence of less obvious interactions between marine methanogens and sulfate-reducing bacteria. PMID:26074892

  2. Geology of tight oil and potential tight oil reservoirs in the lower part of the Green River Formation, Uinta, Piceance, and Greater Green River Basins, Utah, Colorado, and Wyoming

    USGS Publications Warehouse

    Johnson, Ronald C.; Birdwell, Justin E.; Mercier, Tracey J.; Brownfield, Michael E.

    2016-01-01

    The recent successful development of a tight oil play in the Eocene-age informal Uteland Butte member of the lacustrine Green River Formation in the Uinta Basin, Utah, using modern horizontal drilling and hydraulic fracturing techniques has spurred a renewed interest in the tight oil potential of lacustrine rocks. The Green River Formation was deposited by two large lakes, Lake Uinta in the Uinta and Piceance Basins and Lake Gosiute in the Greater Green River Basin. These three basins contain the world’s largest in-place oil shale resources with recent estimates of 1.53 trillion, 1.33 trillion, and 1.44 trillion barrels of oil in place in the Piceance, Uinta, and Greater Green River Basins, respectively. The Uteland Butte member was deposited during an early freshwater stage of the lake in the Uinta Basin prior to deposition of the assessed oil shale intervals. This report only presents information on the early freshwater interval and overlying brackish-water interval in all three basins because these intervals are most likely to have tight oil potential. Burial histories of the three basins were reconstructed to study (1) variations in subsidence and lake development, and (2) post deposition burial that led to the development of a petroleum system in only the Uinta Basin. The Uteland Butte member is a successful tight oil play because it is thermally mature for hydrocarbon generation and contains organic-rich shale, brittle carbonate, and porous dolomite. Abnormally high pressure in parts of the Uteland Butte is also important to production. Variations in organic richness of the Uteland Butte were studied using Fischer assay analysis from oil shale assessments, and pressures were studied using drill-stem tests. Freshwater lacustrine intervals in the Piceance and Greater Green River Basins are immature for hydrocarbon generation and contain much less carbonate than the Uteland Butte member. The brackish-water interval in the Uinta Basin is thermally mature for

  3. Stable carbon isotope discrimination in rice field soil during acetate turnover by syntrophic acetate oxidation or acetoclastic methanogenesis

    NASA Astrophysics Data System (ADS)

    Conrad, Ralf; Klose, Melanie

    2011-03-01

    Rice fields are an important source for the greenhouse gas methane. In Italian rice field soil CH 4 is produced either by hydrogenotrophic and acetoclastic methanogenesis, or by hydrogenotrophic methanogenesis and syntrophic acetate oxidation when temperatures are below and above about 40-45 °C, respectively. In order to see whether these acetate consumption pathways differently discriminate the stable carbon isotopes of acetate, we measured the δ 13C of total acetate and acetate-methyl as well as the δ 13C of CO 2 and CH 4 in rice field soil that had been pre-incubated at 45 °C and then shifted to different temperatures between 25 and 50 °C. Acetate transiently accumulated to about 6 mM, which is about one-third of the amount of CH 4 produced, irrespective of the incubation temperature and the CH 4 production pathway involved. However, the patterns of δ 13C of the CH 4 and CO 2 produced were different at low (25, 30, 35 °C) versus high (40, 45, 50 °C) temperatures. These patterns were consistent with CH 4 being exclusively formed by hydrogenotrophic methanogenesis at high temperatures, and by a combination of acetoclastic and hydrogenotrophic methanogenesis at low temperatures. The patterns of δ 13C of total acetate and acetate-methyl were also different at high versus low temperatures, indicating the involvement of different pathways of production and consumption of acetate at the two temperature regimes. Isotope fractionation during consumption of the methyl group of acetate was more pronounced at low ( α = 1.010-1.025) than at high ( α = 1.0-1.01) temperatures indicating that acetoclastic methanogenesis exhibits a stronger isotope effect than syntrophic acetate oxidation. Small amounts of propionate also transiently accumulated and were analyzed for δ 13C. The δ 13C values slightly increased (by about 10‰) during production and consumption of propionate, but were not affected by incubation temperature. Collectively, our results showed distinct

  4. Clostridiumm ljungdahlii, an anaerobic ethanol and acetate producing microorganism

    DOEpatents

    Gaddy, J.L.; Clausen, E.C.

    1992-12-22

    A newly discovered microorganism was isolated in a biologically pure culture and designated Clostridium ljungdahlii, having the identifying characteristics of ATCC No. 49587. Cultured in an aqueous nutrient medium under anaerobic conditions, this microorganism is capable of producing ethanol and acetate from CO and H[sub 2]O and/or CO[sub 2] and H[sub 2] in synthesis gas. Under optimal growth conditions, the microorganism produces acetate in preference to ethanol. Conversely, under non-growth conditions, ethanol production is favored over acetate. 3 figs.

  5. Clostridiumm ljungdahlii, an anaerobic ethanol and acetate producing microorganism

    DOEpatents

    Gaddy, James L.; Clausen, Edgar C.

    1992-01-01

    A newly discovered microorganism was isolated in a biologically pure culture and designated Clostridium ljungdahlii, having the identifying characteristics of ATCC No. 49587. Cultured in an aqueous nutrient medium under anaerobic conditions, this microorganism is capable of producing ethanol and acetate from CO and H.sub.2 O and/or CO.sub.2 and H.sub.2 in synthesis gas. Under optimal growth conditions, the microorganism produces acetate in preference to ethanol. Conversely, under non-growth conditions, ethanol production is favored over acetate.

  6. Viscosity of Mixtures of α-Tocopherol Acetate + Mesitylene

    NASA Astrophysics Data System (ADS)

    Szwajczaka, Elżbieta; Stagraczyński, Ryszard; Herba, Henryk; Świergielb, Jolanta; Jadżyn, Jan

    2009-08-01

    The paper presents results of the share viscosity measurements performed as a function of temperature and concentration for mixtures of α-tocopherol acetate (vitamine E acetate) and mesitylene, two liquids of essentially different viscosity (four order of magnitude difference at 280 K). The viscosity/ temperature dependence for pure α-tocopherol acetate as well as for the mixtures studied can be well described with the Vogel-Fulcher-Tammann equation. The viscosities of the mixtures exhibit a strong negative deviation from the rule of additive dependence on concentration and for increasing temperature the maximum value of the deviation shows an exponential decreasing.

  7. Leuprolide acetate suppresses pedophilic urges and arousability.

    PubMed

    Schober, Justine M; Kuhn, Phyllis J; Kovacs, Paul G; Earle, James H; Byrne, Peter M; Fries, Ruth A

    2005-12-01

    Cognitive-behavioral psychotherapy was compared with cognitive-behavioral psychotherapy augmented by leuprolide acetate (LA) for suppression of pedophilic behavior. Five male pedophiles (M age, 50 years; range, 36-58) were administered LA by Depo injection for 12 months, followed by saline placebo for 12 months. Testosterone levels, sexual interest preference by visual reaction time (Abel Assessment), penile tumescence (Monarch Penile Plethysmography, PPG), as well as strong sexual urges toward children and masturbatory frequency involving thoughts of children (polygraph), were measured every 3 months. On LA, testosterone decreased to castrate levels. Penile tumescence was significantly suppressed compared with baseline, but sufficient response remained to detect pedophilic interest. Pedophilic interest was also detected by visual reaction times. When asked about having pedophilic urges and masturbating to thoughts of children, all subjects self-reported a decrease. Polygraph responses indicated subjects were not deceptive. On placebo, testosterone and physiologic arousal eventually rose to baseline. As noted by polygraph, at baseline and on placebo, subjects were deceptive regarding increased pedophilic urges and masturbatory frequency. Interest preference, as measured by Abel Assessment and Monarch PPG, was generally unchanged throughout the study. Cognitive-behavioral psychotherapy augmented with LA significantly reduced pedophilic fantasies, urges, and masturbation; however, pedophilic interest did not change during 1 year of therapy. Deceptive responses by polygraph suggested that self-report was unreliable. Follow-up utilizing objective measures is essential for monitoring efficacy of treatment in pedophilia. Our study supports the premise that suppression of pedophilic behavior is possible. LA may augment cognitive-behavioral psychotherapy and help break the sequence leading to a re-offense. PMID:16362253

  8. Comparative density functional theory and density functional tight binding study of 2-anthroic acid on TiO2

    NASA Astrophysics Data System (ADS)

    Manzhos, Sergei

    2016-01-01

    A comparative DFTB (density functional tight binding)-DFT (density functional theory) study of several adsorption modes of 2-anthroic acid on titania is presented. Two parameterizations of DFTB previously used for dye-TiO2 interfaces are tested. DFTB predicts adsorption energies which differ from those computed by DFT not only in magnitude (by up to 0.5 eV) but also in the order among different configurations. The band alignment computed with DFTB is not consistent with DFT results and with experimental data. The strategy of geometry optimization with DFTB followed by single-point DFT calculations also does not necessarily result in plausible adsorption energies.

  9. [The mechanism of acetate assimilation in purple nonsulfur bacteria lacking the glyoxylate pathway: acetate assimilation in Rhodobacter sphaeroides cells].

    PubMed

    Filatova, L V; Berg, I A; Krasil'nikova, E N; Tsygankov, A A; Laurinavichene, T V; Ivanovskiĭ, R N

    2005-01-01

    The mechanism of acetate assimilation in the purple nonsulfur bacterium Rhodobacter sphaeroides, which lacks the glyoxylate pathway, is studied. It is found that the growth of this bacterium in batch and continuous cultures and the assimilation of acetate in cell suspensions are not stimulated by bicarbonate. The consumption of acetate is accompanied by the excretion of glyoxylate and pyruvate into the medium, stimulated by glyoxylate and pyruvate, and inhibited by citramalate. The respiration of cells in the presence of acetate is stimulated by glyoxylate, pyruvate, citramalate, and mesaconate. These data suggest that the citramalate cycle may function in Rba. sphaeroides in the form of an anaplerotic pathway instead of the glyoxylate pathway. At the same time, the low ratio of fixation rates for bicarbonate and acetate exhibited by the Rba. sphaeroides cells (approximately 0.1), as well as the absence of the stimulatory effect of acetate on the fixation of bicarbonate in the presence of the Calvin cycle inhibitor iodoacetate, suggests that pyruvate synthase is not involved in acetate assimilation in the bacterium Rba. sphaeroides. PMID:16119843

  10. Zonula occludens toxin modulates tight junctions through protein kinase C-dependent actin reorganization, in vitro.

    PubMed Central

    Fasano, A; Fiorentini, C; Donelli, G; Uzzau, S; Kaper, J B; Margaretten, K; Ding, X; Guandalini, S; Comstock, L; Goldblum, S E

    1995-01-01

    The intracellular signaling involved in the mechanism of action of zonula occludens toxin (ZOT) was studied using several in vitro and ex vivo models. ZOT showed a selective effect among various cell lines tested, suggesting that it may interact with a specific receptor, whose surface expression on various cells differs. When tested in IEC6 cell monolayers, ZOT-containing supernatants induced a redistribution of the F-actin cytoskeleton. Similar results were obtained with rabbit ileal mucosa, where the reorganization of F-actin paralleled the increase in tissue permeability. In endothelial cells, the cytoskeletal rearrangement involved a decrease of the soluble G-actin pool (-27%) and a reciprocal increase in the filamentous F-actin pool (+22%). This actin polymerization was time- and dose-dependent, and was reversible. Pretreatment with a specific protein kinase C inhibitor, CGP41251, completely abolished the ZOT effects on both tissue permeability and actin polymerization. In IEC6 cells ZOT induced a peak increment of the PKC-alpha isoform after 3 min incubation. Taken together, these results suggest that ZOT activates a complex intracellular cascade of events that regulate tight junction permeability, probably mimicking the effect of physiologic modulator(s) of epithelial barrier function. Images PMID:7635964

  11. Cosolvent gel-like materials from partially hydrolyzed poly(vinyl acetate)s and borax.

    PubMed

    Angelova, Lora V; Terech, Pierre; Natali, Irene; Dei, Luigi; Carretti, Emiliano; Weiss, Richard G

    2011-09-20

    A gel-like, high-viscosity polymeric dispersion (HVPD) based on cross-linked borate, partially hydrolyzed poly(vinyl acetate) (xPVAc, where x is the percent hydrolysis) is described. Unlike hydro-HVPDs prepared from poly(vinyl alcohol) (PVA) and borate, the liquid portion of these materials can be composed of up to 75% of an organic cosolvent because of the influence of residual acetate groups on the polymer backbone. The effects of the degree of hydrolysis, molecular weight, polymer and cross-linker concentrations, and type and amount of organic cosolvent on the rheological and structural properties of the materials are investigated. The stability of the systems is explored through rheological and melting-range studies. (11)B NMR and small-angle neutron scattering (SANS) are used to probe the structure of the dispersions. The addition of an organic liquid to the xPVAc-borate HVPDs results in a drastic increase in the number of cross-linked borate species as well as the agglomeration of the polymer into bundles. These effects result in an increase in the relaxation time and thermal stability of the networks. The ability to make xPVAc-borate HVPDs with very large amounts of and rather different organic liquids, with very different rheological properties that can be controlled easily, opens new possibilities for applications of PVAc-based dispersions. PMID:21848256

  12. Thermal Conductivity of Ethylene Vinyl Acetate Copolymer/Nanofiller Blends

    NASA Technical Reports Server (NTRS)

    Ghose, S.; Watson, K. A.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Lin, Y.; Sun, Y. P.

    2007-01-01

    To reduce weight and increase the mobility, comfort, and performance of future spacesuits, flexible, thermally conductive fabrics and plastic tubes are needed for the Liquid Cooling and Ventilation Garment. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As an approach to raise the thermal conductivity (TC) of an ethylene vinyl acetate copolymer (Elvax 260), it was compounded with three types of carbon based nanofillers: multi-walled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNFs), and expanded graphite (EG). In addition, other nanofillers including metallized CNFs, nickel nanostrands, boron nitride, and powdered aluminum were also compounded with Elvax 260 in the melt at various loading levels. In an attempt to improve compatibility between Elvax 260 and the nanofillers, MWCNTs and EG were modified by surface coating and through noncovalent and covalent attachment of organic molecules containing alkyl groups. Ribbons of the nanocomposites were extruded to form samples in which the nanofillers were aligned in the direction of flow. Samples were also fabricated by compression molding to yield nanocomposites in which the nanofillers were randomly oriented. Mechanical properties of the aligned samples were determined by tensile testing while the degree of dispersion and alignment of nanoparticles were investigated using high-resolution scanning electron microscopy. TC measurements were performed using a laser flash (Nanoflash ) technique. TC of the samples was measured in the direction of, and perpendicular to, the alignment direction. Additionally, tubing was also extruded from select nanocomposite compositions and the TC and mechanical flexibility measured.

  13. Incensole acetate: a novel neuroprotective agent isolated from Boswellia carterii.

    PubMed

    Moussaieff, Arieh; Shein, Na'ama A; Tsenter, Jeanna; Grigoriadis, Savvas; Simeonidou, Constantina; Alexandrovich, Alexander G; Trembovler, Victoria; Ben-Neriah, Yinon; Schmitz, Michael L; Fiebich, Bernd L; Munoz, Eduardo; Mechoulam, Raphael; Shohami, Esther

    2008-07-01

    Boswellia resin has been used as a major anti-inflammatory agent and for the healing of wounds for centuries. Incensole acetate (IA), isolated from this resin, was shown to inhibit the activation of nuclear factor-kappaB, a key transcription factor in the inflammatory response. We now show that IA inhibits the production of inflammatory mediators in an in vitro model system of C6 glioma and human peripheral monocytes. Given the involvement of postinjury inflammation in the pathophysiology and outcome of traumatic brain injury, we examined the effect of IA on the inflammatory process and on the recovery of neurobehavioral and cognitive functions in a mouse model of closed head injury (CHI). In the brains of post-CHI mice, IA reduced glial activation, inhibited the expression of interleukin-1beta, and tumor necrosis factor-alpha mRNAs, and induced cell death in macrophages at the area of trauma. A mild hypothermic effect was also noted. Subsequently, IA inhibited hippocampal neurodegeneration and exerted a beneficial effect on functional outcome after CHI, indicated by reduced neurological severity scores and improved cognitive ability in an object recognition test. This study attributes the anti-inflammatory activity of Boswellia resin to IA and related cembranoid diterpenes and suggests that they may serve as novel neuroprotective agents. PMID:18414499

  14. Transport properties of polyaniline-cellulose-acetate blends

    NASA Astrophysics Data System (ADS)

    Planès, Jérôme; Wolter, Andreas; Cheguettine, Yasmina; Proń, Adam; Genoud, Françoise; Nechtschein, Maxime

    1998-09-01

    Transport properties of polyaniline (PANI)-cellulose acetate (CA) conducting blends have been investigated at various length scales and temperatures. We report on the results of dc and ac conductivity measurements, magnetoresistance and electron-spin resonance (ESR) performed on composite films with PANI weight fraction p ranging from the percolation threshold-pc~=0.1%-to a few percent. Three different PANI doping agents have been tested, namely, camphor sulfonic acid (CSA), di(i-octyl phosphate) (DiOP) and phenyl phosphonic acid (PPA). The percolative behavior of σdc resembles that of published results on PANI/PMMA blends. The onset frequency ωξ of the dispersion in σac appears to follow the scaling law: ωξ~σzdc with z~=1. The temperature dependence is of the form of lnσ(T)~-(T0/T)γ the exponent decreasing from 0.75 to 0.5 with increasing p. The microscopic metallic character of transport is found in ESR and microwave measurements. Spin-dependent conductivity is inferred from the (B/T)2 universal behavior of magnetoresistance. Those results are discussed in conjunction with the ongoing debate on the nature of disorder in conducting polymers-homogeneous versus heterogeneous.

  15. Antifertility mechanisms of gossypol acetic acid in female rats.

    PubMed

    Yang, Y Q; Wu, X Y

    1987-07-01

    Gossypol acetic acid was administered orally (30, 60, 90 and 120 mg/kg/day) on Days 1-5 post coitum to mature female rats. At autopsy on Day 10, pregnancy in most treated animals (6/7 and 6/8) was blocked at high doses (90 and 120 mg/kg/day respectively). As the daily dose decreased to 60 mg/kg/day half (4/8) were not pregnant. However, at a lower dose (30 mg/kg/day), or at a single dose of 200 mg/kg at Day 1 p.c., pregnancy was not blocked. The concentrations of progesterone in the serum of these females were significantly decreased except at the low dose. The numbers of implantation sites in the treated females that did remain pregnant were similar to those in control females except at the dose of 120 mg/kg/day. Gossypol did not retard the development of the preimplantation embryo or cavitation. The Pontamine Blue test revealed that the drug did not interfere with the initiation of implantation. We suggest that gossypol has an antifertility effect in the female rat because it is luteolytic and disrupts post-implantation development. PMID:3656277

  16. Effect of phorbol myristate acetate on secretion of parathyroid hormone

    SciTech Connect

    Morrissey, J.J. )

    1988-01-01

    The influence of phorbol myristate acetate (PMA), an activator of protein kinase c, on the secretion of parathyroid hormone from collagenase-dispersed bovine parathyroid cells was tested. The cells were incubated at low or high concentrations of calcium in the medium, and the hormone secreted into the medium was measured by a radioimmunoassay that recognizes both intact and C-terminal fragments of hormone. A stimulatory effect of PMA at high calcium, seen at PMA concentrations as low as 1.6 nM, did not occur with a biologically inactive 4{alpha}-isomer of phorbol ester, and was independent of changes in cellular adenosine 3{prime},5{prime}-cyclic monophosphate levels. Examination of {sup 32}P-labeled phosphoproteins by two-dimensional gel electrophoresis revealed acidic proteins of {approximately}20,000 and 100,000 Da that were phosphorylated at low and high calcium + 1.6 {mu}M PMA but not at high calcium alone. The protein kinase c activity associated with the membrane fraction of parathyroid cells significantly decreased 40% when the cells were incubated at high vs. low calcium. The data suggest that calcium may regulate parathyroid hormone secretion through changes in protein kinase c activity of the membrane fraction of the cell and protein phosphorylation.

  17. Biosynthesis of the halogenated auxin, 4-chloroindole-3-acetic acid.

    PubMed

    Tivendale, Nathan D; Davidson, Sandra E; Davies, Noel W; Smith, Jason A; Dalmais, Marion; Bendahmane, Abdelhafid I; Quittenden, Laura J; Sutton, Lily; Bala, Raj K; Le Signor, Christine; Thompson, Richard; Horne, James; Reid, James B; Ross, John J

    2012-07-01

    Seeds of several agriculturally important legumes are rich sources of the only halogenated plant hormone, 4-chloroindole-3-acetic acid. However, the biosynthesis of this auxin is poorly understood. Here, we show that in pea (Pisum sativum) seeds, 4-chloroindole-3-acetic acid is synthesized via the novel intermediate 4-chloroindole-3-pyruvic acid, which is produced from 4-chlorotryptophan by two aminotransferases, TRYPTOPHAN AMINOTRANSFERASE RELATED1 and TRYPTOPHAN AMINOTRANSFERASE RELATED2. We characterize a tar2 mutant, obtained by Targeting Induced Local Lesions in Genomes, the seeds of which contain dramatically reduced 4-chloroindole-3-acetic acid levels as they mature. We also show that the widespread auxin, indole-3-acetic acid, is synthesized by a parallel pathway in pea. PMID:22573801

  18. Ice-melting characteristics of calcium magnesium acetate

    NASA Astrophysics Data System (ADS)

    Schenk, R. U.

    1986-01-01

    The objectives of the study are to determine the pertinent properties of Calcium/Magnesium Acetate and to determine the pH and ratio of calcium to magnesium that provide optimum road deicing characteristics.

  19. Deep cavitands featuring functional acetal-based walls.

    PubMed

    Degardin, Melissa; Busseron, Eric; Kim, Dang-A; Ajami, Dariush; Rebek, Julius

    2012-12-18

    The synthesis of deep cavitands with functionalized acetals as a fourth-wall is described. Recognition properties and stabilities of the complexes of two representative cavitands with aliphatic, aromatic, carbocyclic and adamantane guests were evaluated by NMR methods. PMID:23125977

  20. Fragrance material review on 2-(p-tolyloxy)ethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(p-tolyloxy)ethyl acetate when used as a fragrance ingredient is presented. 2-(p-tolyloxy)ethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(p-tolyloxy)ethyl acetate were evaluated, then summarized, and includes physical properties data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414652

  1. A molecular dynamics study of the ionic liquid, choline acetate.

    PubMed

    Willcox, Jon A L; Kim, Hyunjin; Kim, Hyung J

    2016-06-01

    Structural and dynamic properties of the ionic liquid (IL) choline acetate are studied using molecular dynamics (MD) simulations. The hydroxyl group of choline shows significant hydrogen-bonding interactions with the oxygen atoms of acetate. Nearly all choline cations are found to form a hydrogen bond with acetate anions at 400 K, while about 67% of cations participate in hydrogen-bonding interactions at 600 K. At 400 K, subdiffusive and prominent non-Gaussian behavior persist for t > 10 ns. At 600 K, the usual diffusion regime is obtained after a few hundred ps of subdiffusive behavior. Analysis of reorientational motions of acetate ions, particularly those of their short axes, indicates a high degree of dynamic heterogeneity, in agreement with previous work on different IL systems. PMID:27188287

  2. Light and Acetate Regulate a Mitochondrial Malate Dehydrogenase 1

    PubMed Central

    Struck, Friedhelm; Grölz-Krug, Sabine; Boschek, Bruce; Zetsche, Klaus

    1987-01-01

    A malate dehydrogenase was purified from the unicellular green alga Chlorogonium elongatum Dangeard. The enzyme was localized in the mitochondria by immunogold electron microscopy and was found to be present on the cristae. The concentration of the enzyme is regulated by acetate and light. In cells cultured heterotrophically with acetate as carbon source the activity and the concentration of the enzyme is 5- to 6-fold higher than in autotrophic cells. In mixotrophically cultured cells (light and acetate) the enzyme level attains only half of the value of that in heterotrophic cells. Acetate induces an increase of the enzyme concentration while light has an inhibitory effect on this process. Images Fig. 2 Fig. 3 PMID:16665643

  3. Quantification of posterior capsule tightness and motion loss in patients with shoulder impingement.

    PubMed

    Tyler, T F; Nicholas, S J; Roy, T; Gleim, G W

    2000-01-01

    The relationship between posterior capsule tightness and dysfunction has long been recognized clinically but has not been biometrically quantified. The purpose of this study was to quantify changes in range of motion and posterior capsule tightness in patients with dominant or nondominant shoulder impingement. Measurements of posterior capsule tightness and external and internal rotation range of motion were made in 31 patients with shoulder impingement and in 33 controls without shoulder abnormality. Patients with impingement in the nondominant arm had increased posterior capsule tightness and decreased internal and external rotation range of motion compared with controls. Patients with impingement in their dominant arm had increased posterior capsule tightness and reduced internal rotation range of motion but no significant loss of external rotation range of motion compared with controls. Posterior capsule tightness in impingement patients showed a significant correlation with loss of internal rotation range of motion. Patients with shoulder impingement in their nondominant arm had a more global loss of range of motion compared with patients having impingement in their dominant arm. We believe we have described a valid clinical measurement for identifying posterior capsule tightness in patients with shoulder impingement. PMID:11032222

  4. Microorganisms having enhanced resistance to acetate and methods of use

    SciTech Connect

    Brown, Steven D; Yang, Shihui

    2014-10-21

    The present invention provides isolated or genetically modified strains of microorganisms that display enhanced resistance to acetate as a result of increased expression of a sodium proton antiporter. The present invention also provides methods for producing such microbial strains, as well as related promoter sequences and expression vectors. Further, the present invention provides methods of producing alcohol from biomass materials by using microorganisms with enhanced resistance to acetate.

  5. Corrosion resistance of aluminum-magnesium alloys in glacial acetic acid

    SciTech Connect

    Zaitseva, L.V.; Romaniv, V.I.

    1984-05-01

    Vessels for the storage and conveyance of glacial acetic acid are produced from ADO and AD1 aluminum, which are distinguished by corrosion resistance, weldability and workability in the hot and cold conditions but have low tensile strength. Aluminum-magnesium alloys are stronger materials close in corrosion resistance to technical purity aluminum. An investigation was made of the basic alloying components on the corrosion resistance of these alloys in glacial acetic acid. Both the base metal and the weld joints were tested. With an increase in temperature the corrosion rate of all of the tested materials increases by tens of times. The metals with higher magnesium content show more pitting damage. The relationship of the corrosion resistance of the alloys to magnesium content is confirmed by the similar intensity of failure of the joint metal of all of the investigated alloys and by electrochemical investigations. The data shows that AMg3 alloy is close to technically pure ADO aluminum. However, the susceptibility of even this material to local corrosion eliminates the possibility of the use of aluminum-magnesium alloys as reliable constructional materials in glacial acetic acid.

  6. Water dispersible microbicidal cellulose acetate phthalate film

    PubMed Central

    Neurath, A Robert; Strick, Nathan; Li, Yun-Yao

    2003-01-01

    Background Cellulose acetate phthalate (CAP) has been used for several decades in the pharmaceutical industry for enteric film coating of oral tablets and capsules. Micronized CAP, available commercially as "Aquateric" and containing additional ingredients required for micronization, used for tablet coating from water dispersions, was shown to adsorb and inactivate the human immunodeficiency virus (HIV-1), herpesviruses (HSV) and other sexually transmitted disease (STD) pathogens. Earlier studies indicate that a gel formulation of micronized CAP has a potential as a topical microbicide for prevention of STDs including the acquired immunodeficiency syndrome (AIDS). The objective of endeavors described here was to develop a water dispersible CAP film amenable to inexpensive industrial mass production. Methods CAP and hydroxypropyl cellulose (HPC) were dissolved in different organic solvent mixtures, poured into dishes, and the solvents evaporated. Graded quantities of a resulting selected film were mixed for 5 min at 37°C with HIV-1, HSV and other STD pathogens, respectively. Residual infectivity of the treated viruses and bacteria was determined. Results The prerequisites for producing CAP films which are soft, flexible and dispersible in water, resulting in smooth gels, are combining CAP with HPC (other cellulose derivatives are unsuitable), and casting from organic solvent mixtures containing ≈50 to ≈65% ethanol (EtOH). The films are ≈100 µ thick and have a textured surface with alternating protrusions and depressions revealed by scanning electron microscopy. The films, before complete conversion into a gel, rapidly inactivated HIV-1 and HSV and reduced the infectivity of non-viral STD pathogens >1,000-fold. Conclusions Soft pliable CAP-HPC composite films can be generated by casting from organic solvent mixtures containing EtOH. The films rapidly reduce the infectivity of several STD pathogens, including HIV-1. They are converted into gels and thus do not

  7. Bioactivity of cellulose acetate/hydroxyapatite nanoparticle composite fiber by an electro-spinning process.

    PubMed

    Kwak, Dae Hyun; Lee, Eun Ju; Kim, Deug Joong

    2014-11-01

    Hydroxyapatite/cellulose acetate composite webs were fabricated by an electro-spinning process. This electro-spinning process makes it possible to fabricate complex three-dimensional shapes. Nano fibrous web consisting of cellulose acetate and hydroxyapatite was produced from their mixture solution by using an electro-spinning process under high voltage. The surface of the electro-spun fiber was modified by a plasma and alkaline solution in order to increase its bioactivity. The structure, morphology and properties of the electro-spun fibers were investigated and an in-vitro bioactivity test was evaluated in simulated body fluid (SBF). Bioactivity of the electro-spun web was enhanced with the filler concentration and surface treatment. The surface changes of electro-spun fibers modified by plasma and alkaline solution were investigated by FT-IR (Fourier Transform Infrared Spectroscopy) and XPS (X-ray Photoelectron Spectroscopy). PMID:25958547

  8. Sex and age mortality responses in zinc acetate-treated mice

    SciTech Connect

    Hogan, G.R.; Cole, B.S.; Lovelace, J.M.

    1987-07-01

    In regard to trace metal treatment or exposure, a number of variables are known to affect the expression of toxicity concerning its time course and degree. For example, known variables are route of administration, anionic component of the test substance, and sex and age of the recipient animal. Concerning the latter, little, if any, data have been reported dealing with sex- and age-related responses to excess zinc in mammalian systems. The primary purpose of the short communication presented here focuses on the determination of median lethal dose in sexually immature, i.e., juvenile, and adult female and male mice following a single zinc acetate insult. In addition, variation of lethality responses was examined with the age and sex groups to a divided treatment of a lethal dosage of zinc acetate, the injections of which were separated by various intervals.

  9. Synthesis and characterization of polyurethane-cellulose acetate blend membrane for chromium (VI) removal.

    PubMed

    Riaz, Tabinda; Ahmad, Adnan; Saleemi, Sidra; Adrees, Muhammad; Jamshed, Fahad; Hai, Abdul Moqeet; Jamil, Tahir

    2016-11-20

    Blended membranes of polyurethane and cellulose acetate were prepared, characterized and investigated for their performance. Various ratios of cellulose acetate were employed to prepare four different blend membranes. The characteristics of both pure and blend membranes were investigated and results were compared to distinguish their properties. Functional group analysis was carried out by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) of pure and blend samples. Contact angle measurement and water content were evaluated to determine the membrane hydrophilicity. Moreover, the membrane morphology was studied by scanning electron microscopy (SEM). The membrane permeation properties and ability to reject chromium (VI) ions were tested at various pH and pressure by utilizing different salt concentrations. PMID:27561531

  10. Alternanthera sessilis Red Ethyl Acetate Fraction Exhibits Antidiabetic Potential on Obese Type 2 Diabetic Rats

    PubMed Central

    Tan, Kok Keong; Kim, Kah Hwi

    2013-01-01

    The antidiabetic potential of Alternanthera sessilis Red was investigated using the obese type 2 diabetic rats induced by high fat diet and streptozotocin. Three fractions (hexane, ethyl acetate, and water) were obtained from the crude ethanol extract of Alternanthera sessilis Red. Alternanthera sessilis Red ethyl acetate fraction (ASEAF) was found to possess the most potent antihyperglycemic effect through oral glucose tolerance test. The ASEAF was subsequently given to the diabetic rats for two weeks. It was found that two-week administration of ASEAF reduces the fasting blood glucose level, triglyceride level, and free fatty acid level of the rats. ASEAF-treated diabetic rats showed higher pancreatic insulin content and pancreatic total superoxide dismutase activity compared to the untreated diabetic rats. Also, the insulin sensitivity indexes suggested that ASEAF ameliorates the insulin resistant state of the diabetic rats. In conclusion, ASEAF could be developed into a potential antidiabetic agent for the management of type 2 diabetes. PMID:23606892

  11. Disease modifying potential of glatiramer acetate in Huntington's disease

    PubMed Central

    Corey-Bloom, Jody; Jia, Haiqun; Aikin, Alaina M.; Thomas, Elizabeth A.

    2015-01-01

    Background Deficiencies in brain-derived-neurotrophic-factor have been implicated in the pathogenesis of Huntington's disease (HD). Objective Glatiramer acetate, an FDA- approved drug used for the treatment of multiple sclerosis, has been shown to increase brain-derived-neurotrophic-factor levels in immune cells; hence, we investigated whether it could have similar effects in striatal cells. Methods Wild-type and HD striatal cells were treated with glatiramer acetate for 48 hrs. HD transgenic and wild-type mice were injected with glatiramer acetate (1.5 to1.7 mg/mouse) for five days. These treatments were followed by protein measurements for brain-derived-neurotrophic-factor. Results Glatiramer acetate elicited concentration-dependent increases in brain-derived-neurotrophic-factor protein levels in wild-type and HD striatal cells and in striatal tissue from N171-82Q transgenic mice. Glatiramer acetate also improved metabolic activity of HD striatal cells, and significantly reduced the early hyperactivity phenotype exhibited by N171-82Q transgenic mice. Conclusions These findings suggest that glatiramer acetate may represent a useful therapeutic approach for HD. The excellent safety and tolerability record of this compound makes it an ideal candidate for drug repurposing efforts. PMID:25300334

  12. Genetic dissection of acetic acid tolerance in Saccharomyces cerevisiae.

    PubMed

    Geng, Peng; Xiao, Yin; Hu, Yun; Sun, Haiye; Xue, Wei; Zhang, Liang; Shi, Gui-Yang

    2016-09-01

    Dissection of the hereditary architecture underlying Saccharomyces cerevisiae tolerance to acetic acid is essential for ethanol fermentation. In this work, a genomics approach was used to dissect hereditary variations in acetic acid tolerance between two phenotypically different strains. A total of 160 segregants derived from these two strains were obtained. Phenotypic analysis indicated that the acetic acid tolerance displayed a normal distribution in these segregants, and suggested that the acetic acid tolerant traits were controlled by multiple quantitative trait loci (QTLs). Thus, 220 SSR markers covering the whole genome were used to detect QTLs of acetic acid tolerant traits. As a result, three QTLs were located on chromosomes 9, 12, and 16, respectively, which explained 38.8-65.9 % of the range of phenotypic variation. Furthermore, twelve genes of the candidates fell into the three QTL regions by integrating the QTL analysis with candidates of acetic acid tolerant genes. These results provided a novel avenue to obtain more robust strains. PMID:27430512

  13. Acetic acid oxidation and hydrolysis in supercritical water

    SciTech Connect

    Meyer, J.C.; Marrone, P.A.; Tester, J.W.

    1995-09-01

    Acetic acid (CH{sub 3}COOH) hydrolysis and oxidation in supercritical water were examined from 425--600 C and 246 bar at reactor residence times of 4.4 to 9.8 s. Over the range of conditions studied, acetic acid oxidation was globally 0.72 {+-} 0.15 order in acetic acid and 0.27 {+-} 0.15 order in oxygen to a 95% confidence level, with an activation energy of 168 {+-} 21 kJ/mol, a preexponential factor of 10{sup 9.9{+-}1.7}, and an induction time of about 1.5 s at 525 C. Isothermal kinetic measurements at 550 C over the range 160 to 263 bar indicated that pressure or density did not affect the rate of acetic acid oxidation as much as was previously observed in the oxidation of hydrogen or carbon monoxide in supercritical water. Major products of acetic acid oxidation in supercritical water are carbon dioxide, carbon monoxide, methane, and hydrogen. Trace amounts of propenoic acid were occasionally detected. Hydrolysis or hydrothermolysis in the absence of oxygen resulted in approximately 35% conversion of acetic acid at 600 C, 246 bar, and 8-s reactor residence time. Regression of the limited hydrolysis runs assuming a reaction rate first-order in organic gave a global rate expression with a preexponential factor of 10{sup 4.4{+-}1.1} and an activation energy of 94 {+-} 17 kJ/mol.

  14. Influence of Pectoralis Minor Muscle and Upper Trapez Muscle Tightness in Scapular Dyskinesis

    PubMed Central

    Yeşilyaprak, Sevgi Sevi; Yüksel, Ertuğrul; Kalkan, Serpil

    2014-01-01

    Objectives: Alterations in scapular kinematics were found in individuals with shoulder problems compared with healthy individuals. These alterations in scapular kinematics such as changes in the normal position or any abnormal motion of the scapula during active motions are defined as “’Scapular Dyskinesis (SD)”. Relationship between tight muscles and scapular kinematics has been investigated. Pectoralis Minor Muscle Tightness (PMMT) effects scapular motion and make changes in scapular kinematics. Although there are some studies indicating a possible relationship between PMM or Upper Trapezius Muscle Tightness (UTMT) and SD, this relationship hasn’t been investigated yet. The aim of this study was to evaluate the influence of PMMT and UTMT on SD in an asymptomatic population. Methods: One-hundred-eleven participants (mean age: 22.73±3.45 years old, 222 arms, 42 Female-69 Male) were recruited. Subjects were eligible if they were ≥18 years of age, having active full shoulder motion and who has no health problem to hinder them from participate. Individuals with symptoms produced by cervical spine motion, impingement syndrome, frozen shoulder, shoulder instability and a history of shoulder fracture/surgery were excluded. Scapular Dyskinesis Test (SDT) was used to identify SD. PMMT was determined by Pectoralis Minor Index (PMI), UTMT by UTMT Test. Logistic regression analysis performed to ascertain the effects of PMMT and UTMT on the likelihood that participants have SD. Results: SD was identified in 62 arms (27.9%), PMMT in 32 arms (14.4%), and UTMT in 75 arms (33.8%) in total number of participants. PMMT was determined in 23 arms (37.1%) and UTMT in 39 arms (62.9%) in participants with SD. The logistic regression model was statistically significant, X2=65.472, p<.000, df= 2. The model explained 36.8% (Nagelkerke R2) of the variance in SD and correctly classified 78.4% of cases. The Wald criterion demonstrated that both PMMT and UTMT made a significant

  15. Brine shrimp cytotoxicity of crude methanol extract and antispasmodic activity of α-amyrin acetate from Tylophora hirsuta Wall

    PubMed Central

    2013-01-01

    Background We have previously reported that aerial parts of Tylophora hirsuta have antispasmodic profile. The current work is an attempt for isolation of pharmacologically active compound(s) that contribute for its antispasmodic activity. Methods Preliminary phytochemical screening for crude methanol extract of Tylophora hirsuta (Th.Cr) is performed. Brine shrimp cytotoxicity of crude methanol extract is performed. Column chromatography was used for isolation of compounds. Mass spectroscopy, H1 NMR and C13 NMR were used for structural determination of compounds. α-amyrin acetate was tried for possible spasmolytic activity in rabbit’s jejunal preparations and KCl-induced contractions. Results Th.Cr tested positive for saponins, alkaloids, flavonoids and terpenoids. Compound 1 was isolated as α-amyrin acetate. Compound 2 was heptaeicosanol. Crude methanol extract tested positive for brine shrimp cytotoxicity with LC50 492.33± 8.08 mg/ml. Compound 1 tested positive for antispasmodic activity on spontaneous rabbits’ jejunum preparations with EC50 (60 ± 2) × 10-5M. The compound also tested positive on KCl induced contractions with EC50 (72 ± 3) × 10-5M. Conclusions The present work confirms that α-amyrin acetate is has antispasmodic profile and the relaxant effect may be attributed to α-amyrin acetate which is a major compound. PMID:23773697

  16. Growth Inhibition of Enteric Bacteria by Vibrio cholerae in Nutrient Media Containing Lactate, Acetate, or Citrate1

    PubMed Central

    Bhaskaran, K.; Iyer, S. S.; Khan, A. W.; Vora, V. C.

    1974-01-01

    In cross-streak tests on nutrient agar containing lactate, acetate, or citrate, the growth of certain enteric bacteria was inhibited by themselves or by Vibrio cholerae, or by both. This mimicked the activity of bacteriocins, but the phenomenon was attributable to the accumulation of carbonate and increased alkalinity of the media. Images PMID:15830491

  17. Effects of 4-chlorotestosterone acetate on the phagocytic activity of human monocytes: results of double-blind trial

    PubMed Central

    Magliulo, E.; Giraldi, M.; Cattaneo, E.; Marchioni, E.

    1972-01-01

    A comparative trial on 4-chlorotestosterone acetate and placebo was conducted in humans by the double-blind technique. The effects of the drug were tested by measuring the phagocytic activity of blood monocytes in vitro for colloidal carbon. Monocytes from patients treated with 4-chlorotestosterone acetate displayed a phagocytic power significantly higher than that of monocytes from patients treated with the placebo. Such an increased phagocytic activity is discussed in relation to cell mechanisms and their role in anti-infective defence. ImagesFig. 1 PMID:4556011

  18. Long-Term Exposure of Lead Acetate on Rabbit Renal Tissue

    PubMed Central

    Karimfar, Mohammad Hassan; Bargahi, Afshar; Moshtaghi, Darab; Farzadinia, Parviz

    2016-01-01

    Background: Lead has been widely used in different industries for ages. It is one of the heavy metals, highly poisonous even at low doses, and has biochemical, physiological and behavioral side effects on human and animals. It has been shown that lead has toxic effects on different tissues such as neural and genitourinary tissues, cardiovascular systems and blood. Therefore, high attention has been paid to its environmental pollutions. Objectives: Although many histological and biochemical studies have reported about the effects of lead on the renal tissue, there are a few studies about the ultrastructure and morphometric effects of lead on the kidney. Hence, the aim of this study was the evaluation of morphology and morphometrics of rabbit renal urinary barrier ultrastructure following long-term exposure to lead acetate. Materials and Methods: In this experimental study, 20 male New Zealand rabbits were divided into control and test groups (10 in each). The test group was injected intraperitoneally with chronic dose (8.5 mg/kg of body weight) of lead acetate and for the control group the same volume of normal saline was used, every other day for 10 weeks. After anesthetizing, the biopsies of renal tissues were taken for light and electron microscopic morphometric and morphologic analyses. Results: Long-term exposure to lead acetate caused histopathology effects including dilatation, congestion, nuclei heterochromatic effects, increase in diameter of renal tubules and urinary barrier thickness in rabbit renal tissue. Conclusions: Quantitative and qualitative results of long-term lead acetate exposure showed many histopathology side-effects, especially in the urinary barrier. PMID:27195142

  19. Acetic acid-assisted hydrothermal fractionation of empty fruit bunches for high hemicellulosic sugar recovery with low byproducts.

    PubMed

    Kim, Dong Young; Um, Byung Hwan; Oh, Kyeong Keun

    2015-07-01

    Xylose, mannose, and galactose (xmg) recovery from empty fruit bunches using acetic acid-assisted hydrothermal (AAH) fractionation method was investigated. Acetic acid has been demonstrated to be effective in xmg recovery in comparison with the liquid hot-water (LHW) fractionation. The maximum xmg recovery yield (50.7 %) from the empty fruit bunch (EFB) was obtained using AAH fractionation at optimum conditions (6.9 wt.% acetic acid at 170 °C and for 18 min); whereas, only 16.2 % of xmg recovery was obtained from the LHW fractionation at the same reaction conditions (170 °C and 18 min). Releasing out the glucose from EFB was kept at low level (<1.0 %) through all tested conditions and consequently negligible 5-HMF and formic acid were analyzed in the hydrolyzate. The production of furfural was also resulted with extremely low level (1.0 g/L). PMID:25962829

  20. Rhodium(III)-catalyzed C-C coupling of 7-azaindoles with vinyl acetates and allyl acetates.

    PubMed

    Li, Shuai-Shuai; Wang, Cheng-Qi; Lin, Hui; Zhang, Xiao-Mei; Dong, Lin

    2016-01-01

    The behaviour of electron-rich alkenes with 7-azaindoles in rhodium(III)-catalyzed C-H activation is investigated. Various substituted vinyl acetates and allyl acetates as coupling partners reacted smoothly providing a wide variety of 7-azaindole derivatives, and the selectivity of the coupling reaction is alkene-dependent. In addition, the approaches of rhodium(III)-catalyzed dehydrogenative Heck-type reaction (DHR) and carbonylation reaction were quite novel and simple. PMID:26553424

  1. Pulmonary and percutaneous absorption of 2-propoxyethyl acetate and 2-ethoxyethyl acetate in beagle dogs.

    PubMed Central

    Guest, D; Hamilton, M L; Deisinger, P J; DiVincenzo, G D

    1984-01-01

    A comparison was made of the absorption and elimination rates of 2-propoxyethyl acetate (PEA) and 2-ethoxyethyl acetate (EEA) following inhalation, dermal application or IV administration. Male beagle dogs were exposed to 50 ppm PEA or EEA for 5 hr, and breath samples were collected during the exposure and a 3-hr recovery period. Both compounds were rapidly absorbed through the lungs. After 10 min of exposure, the concentrations of the parent compounds in the expired breath were 5 to 10 ppm (80-90% absorption) and reached plateau values at about 3 hr of 13 ppm for PEA (74% absorption) and 16 ppm for EEA (68% absorption). Post-exposure breath samples declined exponentially to 0.5 ppm and 2 ppm after 3 hr for PEA and EEA, respectively. Expired concentrations of PEA were slightly, but significantly (p less than 0.025), lower than those of EEA at corresponding times during the exposure. After IV dosing with 1 mg/kg [ethyl-1,2-14C]PEA, the urine contained 61% and 88% of the dose in 4 and 24 hr, respectively. [14C]EEA was eliminated more slowly, with 20% and 61% of the dose appearing in the urine in 4 and 24 hr, respectively. Blood elimination half-lives were 1.6 hr for [14C]PEA and 7.9 hr for [14C]EEA. Only trace amounts of 14CO2 (less than 1%) or volatile materials (less than 0.1%) were detected in the expired air with either compound. For studies of percutaneous absorption, [14C]PEA or [14C]EEA was added to undiluted compound and applied in a glass cell to a shaved area on a dog's thorax for 30 or 60 min.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6499802

  2. Defense technique takes guesswork out of tight reservoir fracturing jobs

    SciTech Connect

    Duey, R.

    1996-05-01

    Enserch exploration and the Los Alamos National Laboratory are using a highly sensitive defense technology to map fractures in an East Texas field. A process known as nuclear test verification, using highly sophisticated detectors can actually map fractures as they occur.

  3. An Investigation of Hydraulic Fracturing Initiation and Near-Wellbore Propagation from Perforated Boreholes in Tight Formations

    NASA Astrophysics Data System (ADS)

    Fallahzadeh, S. H.; Rasouli, V.; Sarmadivaleh, M.

    2015-03-01

    In this study, hydraulic fracturing tests were conducted on 10 and 15 cm synthetically manufactured cubic tight mortar samples. The use of cube samples allowed application of three independent stresses to mimic real far field stress conditions. A true triaxial stress cell was used for this purpose. The lab test parameters were scaled to simulate the operations at field scale. The hole and perforations were made into the sample after casting and curing were completed. Various scenarios of vertical and horizontal wells and in situ stress regimes were modeled. These factors are believed to play a significant role in fracture initiation and near-wellbore propagation behavior; however, they are not independent parameters, hence should be analyzed simultaneously. In addition to experimental studies, analytical solutions were developed to simulate the mechanism of fracture initiation in perforated boreholes in tight formations. Good agreements were observed between the experimental and analytical results. The results of this study showed that a lower initiation pressure is observed when the minimum stress component is perpendicular to the axis of the perforations. It was also seen that, even when the cement sheath behind the casing fails, the orientation of the perforations may affect the initiation of the induced fracture noticeably. Furthermore, it was found that stress anisotropy influences the fracturing mechanism in a perforated borehole, and affects the geometry of the initiated near-wellbore fracture.

  4. Reversible Opening of Intercellular Junctions of Intestinal Epithelial and Brain Endothelial Cells With Tight Junction Modulator Peptides.

    PubMed

    Bocsik, Alexandra; Walter, Fruzsina R; Gyebrovszki, Andrea; Fülöp, Lívia; Blasig, Ingolf; Dabrowski, Sebastian; Ötvös, Ferenc; Tóth, András; Rákhely, Gábor; Veszelka, Szilvia; Vastag, Monika; Szabó-Révész, Piroska; Deli, Mária A

    2016-02-01

    The intercellular junctions restrict the free passage of hydrophilic compounds through the paracellular clefts. Reversible opening of the tight junctions of biological barriers is investigated as one of the ways to increase drug delivery to the systemic circulation or the central nervous system. Six peptides, ADT-6, HAV-6, C-CPE, 7-mer (FDFWITP, PN-78), AT-1002, and PN-159, acting on different integral membrane and linker junctional proteins were tested on Caco-2 intestinal epithelial cell line and a coculture model of the blood-brain barrier. All peptides tested in nontoxic concentrations showed a reversible tight junctions modulating effect and were effective to open the paracellular pathway for the marker molecules fluorescein and albumin. The change in the structure of cell-cell junctions was verified by immunostaining for occludin, claudin-4,-5, ZO-1, β-catenin, and E-cadherin. Expression levels of occludin and claudins were measured in both models. We could demonstrate a selectivity of C-CPE, ADT-6, and HAV-6 peptides for epithelial cells and 7-mer and AT-1002 peptides for brain endothelial cells. PN-159 was the most effective modulator of junctional permeability in both models possibly acting via claudin-1 and -5. Our results indicate that these peptides can be effectively and selectively used as potential pharmaceutical excipients to improve drug delivery across biological barriers. PMID:26869428

  5. Assessment of unconventional tight-gas resources of the Magallanes Basin Province, Chile, 2015

    USGS Publications Warehouse

    Schenk, Christopher J.; Charpentier, Ronald R.; Pitman, Janet K.; Tennyson, Marilyn E.; Brownfield, Michael E.; Gaswirth, Stephanie B.; Le, Phuong A.; Leathers-Miller, Heidi M.; Marra, Kristen R.

    2016-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey assessed a technically recoverable mean resource of 8.3 trillion cubic feet of unconventional tight gas in the Zona Glauconitica of the Magallanes Basin Province, Chile.

  6. sp3s* Tight-Binding Parameters for Transport Simulations in Compound Semiconductors

    NASA Technical Reports Server (NTRS)

    Klimeck, G.; Bowen, R.; Boykin, T.; Cwik, T.

    1999-01-01

    A genetic algorithm approach is used to fit orbital interaction energies of sp3s* tight-binding models for the nine binary compound semiconductors consistent of Ga, Al, In and As, P, Sb at room temperature.

  7. Effect of tight clothes on cervical and thoracic spine muscles during shoulder abduction

    PubMed Central

    Kim, Min-hee; Yoo, Won-gyu

    2016-01-01

    [Purpose] The purpose of this study was investigated the effect of tight clothes on cervical and thoracic spine muscles activities during shoulder abduction. [Subjects and Methods] The subjects of this study were 10 healthy males. The subjects performed two shoulder abduction trials for each of two jacket-wearing conditions. The right upper, middle, and lower trapezius and serratus anterior muscles activities were measured using a surface electromyography system during right shoulder abduction. [Results] The upper and middle trapezius muscle activities during shoulder abduction were significantly increased under the tight-jacket conditions compared with the general-jacket conditions. The lower trapezius and serratus anterior muscle activities were significantly decreased under the tight-jacket conditions compared with the general-jacket conditions. [Conclusion] The results of this study suggest that normal scapular movements did not occur sufficiently when wearing a tight jacket. PMID:27313348

  8. Persistent tight hamstrings following conservative treatment for apophyseal ring fracture in adolescent athletes: critical appraisal.

    PubMed

    Miyagi, Ryo; Sairyo, Koichi; Sakai, Toshinori; Tezuka, Fumitake; Kitagawa, Yasuhiro; Dezawa, Akira

    2014-01-01

    Apophyseal ring fracture is a unique disease in children and adolescents. Its clinical features include low back pain, sciatica, paravertebral muscle spasm and tenderness, restricted back motion, neurological symptoms, and tight hamstrings. For all athletes, body flexibility is one of the most important factors for better performance. Therefore, persistent tight hamstrings has a negative influence on athletic performance. In this report, we present two adolescent athletes with apophyseal ring fracture treated successfully by conservative treatment for severe low back pain (LBP) and leg pain, despite having persistent tight hamstrings for more than one year. Unlike herniated nucleus pulposus, bony fragments in the spinal canal never disappear. Although conservative treatment can alleviate LBP and leg pain, surgical removal of fragments is considered when symptoms such as tight hamstrings and restricted lumbar motion due to canal stenosis are found, particularly in athletes. PMID:25264071

  9. Tetrazole acetic acid: Tautomers, conformers, and isomerization

    NASA Astrophysics Data System (ADS)

    Araujo-Andrade, C.; Reva, I.; Fausto, R.

    2014-02-01

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol-1 energy range and should be appreciably populated at the sublimation temperature (˜330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol-1) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol-1). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm-1, where the first OH stretching overtone vibrations of 1ccc and 2pcc occur. The

  10. Tetrazole acetic acid: tautomers, conformers, and isomerization.

    PubMed

    Araujo-Andrade, C; Reva, I; Fausto, R

    2014-02-14

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol(-1) energy range and should be appreciably populated at the sublimation temperature (∼330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol(-1)) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol(-1)). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm(-1), where the first OH stretching overtone vibrations of 1ccc and 2pcc occur

  11. Tetrazole acetic acid: Tautomers, conformers, and isomerization

    SciTech Connect

    Araujo-Andrade, C.; Reva, I. Fausto, R.

    2014-02-14

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0–8 kJ mol{sup −1} energy range and should be appreciably populated at the sublimation temperature (∼330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol{sup −1}) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol{sup −1}). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm{sup −1}, where the first OH stretching overtone

  12. Long-range correction for tight-binding TD-DFT

    NASA Astrophysics Data System (ADS)

    Humeniuk, Alexander; Mitrić, Roland

    2015-10-01

    We present two improvements to the tight-binding approximation of time-dependent density functional theory (TD-DFTB): First, we add an exact Hartree-Fock exchange term, which is switched on at large distances, to the ground state Hamiltonian and similarly to the coupling matrix that enters the linear response equations for the calculation of excited electronic states. We show that the excitation energies of charge transfer states are improved relative to the standard approach without the long-range correction by testing the method on a set of molecules from the database in Peach et al. [J. Chem. Phys. 128, 044118 (2008)] which are known to exhibit problematic charge transfer states. The degree of spatial overlap between occupied and virtual orbitals indicates where TD-DFTB and long-range corrected TD-DFTB (lc-TD-DFTB) can be expected to produce large errors. Second, we improve the calculation of oscillator strengths. The transition dipoles are obtained from Slater Koster files for the dipole matrix elements between valence orbitals. In particular, excitations localized on a single atom, which appear dark when using Mulliken transition charges, acquire a more realistic oscillator strength in this way. These extensions pave the way for using lc-TD-DFTB to describe the electronic structure of large chromophoric polymers, where uncorrected TD-DFTB fails to describe the high degree of conjugation and produces spurious low-lying charge transfer states.

  13. Long-range correction for tight-binding TD-DFT

    SciTech Connect

    Humeniuk, Alexander; Mitrić, Roland

    2015-10-07

    We present two improvements to the tight-binding approximation of time-dependent density functional theory (TD-DFTB): First, we add an exact Hartree-Fock exchange term, which is switched on at large distances, to the ground state Hamiltonian and similarly to the coupling matrix that enters the linear response equations for the calculation of excited electronic states. We show that the excitation energies of charge transfer states are improved relative to the standard approach without the long-range correction by testing the method on a set of molecules from the database in Peach et al. [J. Chem. Phys. 128, 044118 (2008)] which are known to exhibit problematic charge transfer states. The degree of spatial overlap between occupied and virtual orbitals indicates where TD-DFTB and long-range corrected TD-DFTB (lc-TD-DFTB) can be expected to produce large errors. Second, we improve the calculation of oscillator strengths. The transition dipoles are obtained from Slater Koster files for the dipole matrix elements between valence orbitals. In particular, excitations localized on a single atom, which appear dark when using Mulliken transition charges, acquire a more realistic oscillator strength in this way. These extensions pave the way for using lc-TD-DFTB to describe the electronic structure of large chromophoric polymers, where uncorrected TD-DFTB fails to describe the high degree of conjugation and produces spurious low-lying charge transfer states.

  14. Nonadiabatic Molecular Dynamics for Thousand Atom Systems: A Tight-Binding Approach toward PYXAID.

    PubMed

    Pal, Sougata; Trivedi, Dhara J; Akimov, Alexey V; Aradi, Bálint; Frauenheim, Thomas; Prezhdo, Oleg V

    2016-04-12

    Excited state dynamics at the nanoscale requires treatment of systems involving hundreds and thousands of atoms. In the majority of cases, depending on the process under investigation, the electronic structure component of the calculation constitutes the computation bottleneck. We developed an efficient approach for simulating nonadiabatic molecular dynamics (NA-MD) of large systems in the framework of the self-consistent charge density functional tight binding (SCC-DFTB) method. SCC-DFTB is combined with the fewest switches surface hopping (FSSH) and decoherence induced surface hopping (DISH) techniques for NA-MD. The approach is implemented within the Python extension for the ab initio dynamics (PYXAID) simulation package, which is an open source NA-MD program designed to handle nanoscale materials. The accuracy of the developed approach is tested with ab initio DFT and experimental data, by considering intraband electron and hole relaxation, and nonradiative electron-hole recombination in a CdSe quantum dot and the (10,5) semiconducting carbon nanotube. The technique is capable of treating accurately and efficiently excitation dynamics in large, realistic nanoscale materials, employing modest computational resources. PMID:26954907

  15. IQGAP1 controls tight junction formation through differential regulation of claudin recruitment

    PubMed Central

    Tanos, Barbara E.; Perez Bay, Andres E.; Salvarezza, Susana; Vivanco, Igor; Mellinghoff, Ingo; Osman, Mahasin; Sacks, David B.; Rodriguez-Boulan, Enrique

    2015-01-01

    ABSTRACT IQGAP1 is a scaffolding protein previously implicated in adherens junction formation. However, its role in the establishment or maintenance of tight junctions (TJs) has not been explored. We hypothesized that IQGAP1 could regulate TJ formation by modulating the expression and/or localization of junctional proteins, and we systematically tested this hypothesis in the model Madin-Darby canine kidney (MDCK) cell line. We find that IQGAP1 silencing enhances a transient increase in transepithelial electrical resistance (TER) observed during the early stages of TJ formation (Cereijido et al., 1978). Quantitative microscopy and biochemical experiments suggest that this effect of IQGAP1 on TJ assembly is accounted for by reduced expression and TJ recruitment of claudin 2, and increased TJ recruitment of claudin 4. Furthermore, we show that IQGAP1 also regulates TJ formation through its interactor CDC42, because IQGAP1 knockdown increases the activity of the CDC42 effector JNK and dominant-negative CDC42 prevents the increase in TER caused by IQGAP1 silencing. Hence, we provide evidence that IQGAP1 modulates TJ formation by a twofold mechanism: (1) controlling the expression and recruitment of claudin 2 and recruitment of claudin 4 to the TJ, and (2) transient inhibition of the CDC42–JNK pathway. PMID:25588839

  16. Diagnosis of Musculus Gastrocnemius Tightness - Key Factors for the Clinical Examination.

    PubMed

    Baumbach, Sebastian F; Braunstein, Mareen; Regauer, Markus; Böcker, Wolfgang; Polzer, Hans

    2016-01-01

    Common foot and ankle pathologies have been linked to isolated Musculus gastrocnemius tightness (MGT). Various examination techniques have been described to assess MGT. Still, a standardized examination procedure is missing. Literature argues for weightbearing examination but the degree of knee flexion needed to eliminate the restraining effect of the M. gastrocnemius on ankle dorsiflexion (ADF) is unknown. This manuscript investigates the effect of knee flexion on ankle dorsiflexion and provides a detailed description of a standardized examination protocol. Examination on 20 healthy individuals revealed, that 20° of knee flexion is sufficient to fully eliminate the influence of the M. gastrocnemius on ADF. This builds the prerequisite for a standardized examination for MGT. Non-weightbearing and weightbearing examination of ADF has to be conducted with the knee fully extended and at least 20° flexed. Two investigators should conduct non-weightbearing testing with the subject in supine position. In order to obtain reliable results, the axis of the fibula should be marked. One examiner can conduct weightbearing examination with the subject in lunge stance. Isolated MGT is present if ADF is impaired with the knee fully extended and knee flexion results in a significant ADF increase. The herein presented standardized examination is the prerequisite for future studies aiming at establishing norm values. PMID:27500825

  17. Repeatable, Inducible Micro-RNA-Based Technology Tightly Controls Liver Transgene Expression

    PubMed Central

    Oprea, Iulian I; Viola, Joana R; Moreno, Pedro M D; Simonson, Oscar E; Rodin, Sergey; Teller, Nathalie; Tryggvason, Karl; Lundin, Karin E; Girnita, Leonard; Smith, Carl Inge Edvard

    2014-01-01

    Inducible systems for gene expression emerge as a new class of artificial vectors offering temporal and spatial exogenous control of gene expression. However, most inducible systems are less efficient in vivo and lack the target-organ specificity. In the present study, we have developed and optimized an oligonucleotide-based inducible system for the in vivo control of transgenes in the liver. We generated a set of simple, inducible plasmid-vectors based on the addition of four units of liver-specific miR-122 target sites to the 3′untranslated region of the gene of interest. Once the vector was delivered into hepatocytes this modification induced a dramatic reduction of gene expression that could be restored by the infusion of an antagomir for miR-122. The efficiency of the system was tested in vivo, and displayed low background and strong increase in gene expression upon induction. Moreover, gene expression was repeatedly induced even several months after the first induction showing no toxic effect in vivo. By combining tissue-specific control elements with antagomir treatment we generated, optimized and validated a robust inducible system that could be used successfully for in vivo experimental models requiring tight and cyclic control of gene expression. PMID:24983837

  18. Flow visualization of CO2 in tight shale formations at reservoir conditions

    NASA Astrophysics Data System (ADS)

    Fernø, M. A.; Hauge, L. P.; Uno Rognmo, A.; Gauteplass, J.; Graue, A.

    2015-09-01

    The flow of CO2 in porous media is fundamental to many engineering applications and geophysical processes. Yet detailed CO2 flow visualization remains challenging. We address this problem via positron emission tomography using 11C nuclides and apply it to tight formations—a difficult but relevant rock type to investigate. The results represent an important technical advancement for visualization and quantification of flow properties in ultratight rocks and allowed us to observe that local rock structure in a layered, reservoir shale (K = 0.74 µdarcy) sample dictated the CO2 flow path by the presence of high-density layers. Diffusive transport of CO2 in a fractured sample (high-permeable sandstone) was also visualized, and an effective diffusion coefficient (Di = 2.2 · 10-8 m2/s) was derived directly from the dynamic distribution of CO2. During CO2 injection tests for oil recovery from a reservoir shale sample we observed a recovery factor of RF = 55% of oil in place without fracturing the sample.

  19. Tight junction disruption: Helicobacter pylori and dysregulation of the gastric mucosal barrier

    PubMed Central

    Caron, Tyler J; Scott, Kathleen E; Fox, James G; Hagen, Susan J

    2015-01-01

    Long-term chronic infection with Helicobacter pylori (H. pylori) is a risk factor for gastric cancer development. In the multi-step process that leads to gastric cancer, tight junction dysfunction is thought to occur and serve as a risk factor by permitting the permeation of luminal contents across an otherwise tight mucosa. Mechanisms that regulate tight junction function and structure in the normal stomach, or dysfunction in the infected stomach, however, are largely unknown. Although conventional tight junction components are expressed in gastric epithelial cells, claudins regulate paracellular permeability and are likely the target of inflammation or H. pylori itself. There are 27 different claudin molecules, each with unique properties that render the mucosa an intact barrier that is permselective in a way that is consistent with cell physiology. Understanding the architecture of tight junctions in the normal stomach and then changes that occur during infection is important but challenging, because most of the reports that catalog claudin expression in gastric cancer pathogenesis are contradictory. Furthermore, the role of H. pylori virulence factors, such as cytotoxin-associated gene A and vacoulating cytotoxin, in regulating tight junction dysfunction during infection is inconsistent in different gastric cell lines and in vivo, likely because non-gastric epithelial cell cultures were initially used to unravel the details of their effects on the stomach. Hampering further study, as well, is the relative lack of cultured cell models that have tight junction claudins that are consistent with native tissues. This summary will review the current state of knowledge about gastric tight junctions, normally and in H. pylori infection, and make predictions about the consequences of claudin reorganization during H. pylori infection. PMID:26523106

  20. Exploring tight junction alteration using double fluorescent probe combination of lanthanide complex with gold nanoclusters

    PubMed Central

    Wang, Xinyi; Wang, Na; Yuan, Lan; Li, Na; Wang, Junxia; Yang, Xiaoda

    2016-01-01

    Tight junctions play a key role in restricting or regulating passage of liquids, ions and large solutes through various biological barriers by the paracellular route. Changes in paracellular permeation indicate alteration of the tight junction. However, it is very difficult to obtain the structural change information by measuring paracellular flux based on transepithelial electrical resistance or using fluorescein-labeled dextrans. Here we show that the BSA and GSH stabilized gold nanoclusters exhibit marginal cytotoxicity and pass through the MDCK monolayer exclusively through the paracellular pathway. We propose a double fluorescence probe strategy, the combination of a proven paracellular indicator (europium complex) with fluorescent gold nanoclusters. We calculate changes of structural parameters in tight junctions based on determination of the diffusion coefficients of the probes. Two different types of tight junction openers are used to validate our strategy. Results show that EDTA disrupts tight junction structures and induces large and smooth paracellular pore paths with an average radius of 17 nm, but vanadyl complexes induce paths with the radius of 6 nm. The work suggests that the double fluorescence probe strategy is a useful and convenient approach for in vitro investigation of tight junction structural alternations caused by pharmacological or pathological events. PMID:27574102