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Sample records for degraded containment penetrations

  1. Containment penetration elastomer seal leak rate tests

    SciTech Connect

    Bridges, T.L.

    1987-07-01

    Tests were performed on three elastomer seal designs commonly used for nuclear plant containment mechanical penetrations. The objective of this research project is to obtain an understanding of the integrity and leakage behavior of these seal designs under severe accident temperature and pressure conditions. The three designs tested and the seal materials used in the tests were: (1) double tongue-and-groove design with silicone rubber seals, (2) double-O-ring design with neoprene and ethylene-propylene (EPDM) seals, and (3) double gumdrop design with neoprene and EPDM seals. The effects of thermal aging and angular rotations of flange mating surfaces were determined. The test results provide information required to characterize the leakage behavior of penetrations under severe accident conditions. 3 refs., 10 figs., 12 tabs.

  2. Characterization of nuclear reactor containment penetrations. Preliminary report

    SciTech Connect

    Bump, T.R.; Seidensticker, R.W.; Shackelford, M.A.; Gambhir, V.K.; McLennan, G.L.

    1984-06-01

    This report summarizes the survey work conducted by Argonne National Laboratory on the design and details of major penetrations in 22 nuclear power plants. The survey includes all containment types and materials in current use. It also includes details of all types of penetrations (except for electrical penetration assemblies and valves) and the seals and gaskets used in them. The report provides a test matrix for testing major penetrations and for testing seals and gaskets in order to evaluate their leakage potential under severe accident conditions.

  3. Implications of Charge Penetration for Heteroatom-Containing Organic Semiconductors.

    PubMed

    Gryn'ova, Ganna; Corminboeuf, Clemence

    2016-12-15

    The noncovalent interactions of neutral π-conjugated cores, pertinent to organic semiconductor materials, are intimately related to their charge transport properties and involve a subtle interplay of dispersion, Pauli repulsion, and electrostatic contributions. Realizing structural arrangements that are both energetically preferred and sufficiently conductive is a challenge. We tackle this problem by means of charge penetration contribution to the interaction energy, boosted in systems containing large heteroatoms (e.g., sulfur, selenium, phosphorus, silicon, and arsenic). We find that in both the model and "realistic" dimers of such heteroatom-containing cores dispersion is balanced out by the exchange and interaction energy is instead governed by substantial charge penetration. These systems also feature stronger electronic couplings compared to the dispersion-driven dimers of oligoacenes and/or the herringbone assemblies. Thus, charge penetration, enhanced in the π-conjugated cores comprising larger heteroatoms, arises as an attractive strategy toward potentially more stable and efficient organic electronic materials.

  4. Penetration enhancer-containing vesicles: composition dependence of structural features and skin penetration ability.

    PubMed

    Manconi, M; Caddeo, C; Sinico, C; Valenti, D; Mostallino, M C; Lampis, S; Monduzzi, M; Fadda, A M

    2012-10-01

    In this work, we focused on how composition and preparation method of vesicles might affect their morphological features and delivery performances. Penetration Enhancer-containing Vesicles, PEVs, vesicles containing a water miscible penetration enhancer (Transcutol® P; 10%, 20%, 30% v/v) and encapsulating diclofenac sodium, were formulated and compared with conventional liposomes. A cheap and unpurified commercial mixture of phospholipids, fatty acids, and triglycerides (Phospholipon® 50) was used, and the effects of this heterogeneous composition (along with the presence or absence of transcutol and the production method) on vesicle morphology, size, surface charge, drug loading, and stability were investigated. The variations in vesicle structure, bilayer thickness, and number of lamellae were assessed by TEM and Small and Wide Angle X-ray Scattering, which also proved the liquid state of the vesicular bilayer. Further, vesicles were evaluated for ex vivo (trans)dermal delivery, and their mode of action was studied performing a pre-treatment test and confocal laser scanning microscopy analyses. Results showed the formation of multi- and unilamellar vesicles that provided improved diclofenac delivery to pig skin, influenced by vesicle lipid composition and structure. Images of the qualitative CLSM analyses support the conclusion that PEVs enhance drug transport by penetrating intact the stratum corneum, thanks to a synergic effect of vesicles and penetration enhancer. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Characterization of nuclear reactor containment penetrations. Final report

    SciTech Connect

    Shackelford, M.H.; Bump, T.R.; Seidensticker, R.W.

    1985-02-01

    This report concludes a preliminary report prepared by ANL for Sandia, published as NUREG/CR-3855, in June 1984. The preliminary report, NUREG/CR-3855, presented the results of a survey of nuclear reactor containment penetrations, covering the number of plants surveyed at that time (22 total). Since that time, an additional 26 plants have been included in the survey. This final report serves two purposes: (1) to add the summary data sheets and penetration details for the additional plants now included in the survey; and (2) to confirm, revise, or add to analyses and discussions presented in the first report which, of course, were based solely on the earlier sample of 22 plants. This final report follows the outline and format of the preliminary survey report. In general, changes and additions to the preliminary report are implied, rather than stated as such to avoid repeated reference to that report. If no changes have been made in a section the title of the section of the previous report is simply repeated followed by ''No Changes''. Some repetition is used for continuity and clarity.

  6. The resistance to chloride penetration of concrete containing nano-particles for pavement

    NASA Astrophysics Data System (ADS)

    Zhang, Mao-hua; Li, Hui

    2006-03-01

    The resistance to chloride penetration of concrete containing nano-particles (TiO II and SiO II) for pavement is experimentally investigated and compared with that of plain concrete, the concrete containing polypropylene (PP) fibers and the concrete containing both nano-particles and PP fibers. The test results indicate that the addition of nano-particles (TiO II and SiO II) improves the resistance to chloride penetration of concrete. The effectiveness of nano-TiO II in improving the resistance to chloride penetration reduces with increasing content of nano-TiO II, and the similar results can be found for the concrete containing nano-SiO II. The resistance to chloride penetration of concrete containing nano-TiO II is better than that containing the same amount of nano-SiO II. However, the resistance to chloride penetration of concrete containing PP fibers is decreased. The larger the content of PP fibers is, the lower the resistance to chloride penetration of concrete is. For the concrete containing both nano-particles and PP fibers, the resistance to chloride penetration is also reduced and even lower than the concrete only containing the same amount of PP fibers. The relationship between the chloride diffusion coefficient and compressive strength of concrete approaches hyperbola basically, which shows that the resistance to chloride penetration of concrete enhances with increasing compressive strength and proves that compressive strength is an important factor influencing the resistance to chloride penetration of concrete.

  7. Degradation of waste gas containing toluene in an airlift bioreactor.

    PubMed

    Lo, Cheng-Shing; Hwang, Shyh-Jye

    2004-04-01

    Suspension microorganisms in an internal-loop airlift bioreactor were utilized to treat waste gas containing toluene. The working volume of the reactor was 35 L, and the biomass concentration was 3 kg/m3. The gas pollutant flowed into the reactor from the bottom; it then transferred from the gas phase to the liquid phase and was degraded by the microorganisms suspended in the liquid phase. The microorganisms were able to degrade 50-90% of the inlet toluene when its concentration was from 0.5 to 10 g/m3, and the superficial gas velocity ranged from 0.15 to 1.23 cm/s. A comprehensive mathematical model was also developed to describe the overall degradation process of toluene in the internal-loop airlift bioreactor. The overall degradation process included gas flow, gas-liquid mass transfer, flow and dispersion of the liquid phase, and microbial kinetics. The hydrodynamic properties including the gas and liquid superficial velocities, the gas holdup, the volumetric mass transfer coefficients of toluene and oxygen, and the microbial kinetics were obtained for this model. The substrate inhibition theory was used to simulate the microorganism growth kinetics, and its kinetic constants were obtained experimentally. The penetration theory was used to predict the volumetric mass transfer coefficient. And the drift-flux theory was used to predict the hydrodynamic properties in each section (riser, gas-liquid separator, downcomer, and bottom) of the airlift bioreactor. The concentration distributions of toluene and oxygen in the airlift bioreactor and the removal efficiency of toluene predicted by the mathematical model agreed well with the experimental data.

  8. Infusion fluids contain harmful glucose degradation products

    PubMed Central

    Bryland, Anna; Broman, Marcus; Erixon, Martin; Klarin, Bengt; Lindén, Torbjörn; Friberg, Hans; Wieslander, Anders; Kjellstrand, Per; Ronco, Claudio; Carlsson, Ola

    2010-01-01

    Purpose Glucose degradation products (GDPs) are precursors of advanced glycation end products (AGEs) that cause cellular damage and inflammation. We examined the content of GDPs in commercially available glucose-containing infusion fluids and investigated whether GDPs are found in patients’ blood. Methods The content of GDPs was examined in infusion fluids by high-performance liquid chromatography (HPLC) analysis. To investigate whether GDPs also are found in patients, we included 11 patients who received glucose fluids (standard group) during and after their surgery and 11 control patients receiving buffered saline (control group). Blood samples were analyzed for GDP content and carboxymethyllysine (CML), as a measure of AGE formation. The influence of heat-sterilized fluids on cell viability and cell function upon infection was investigated. Results All investigated fluids contained high concentrations of GDPs, such as 3-deoxyglucosone (3-DG). Serum concentration of 3-DG increased rapidly by a factor of eight in patients receiving standard therapy. Serum CML levels increased significantly and showed linear correlation with the amount of infused 3-DG. There was no increase in serum 3-DG or CML concentrations in the control group. The concentration of GDPs in most of the tested fluids damaged neutrophils, reducing their cytokine secretion, and inhibited microbial killing. Conclusions These findings indicate that normal standard fluid therapy involves unwanted infusion of GDPs. Reduction of the content of GDPs in commonly used infusion fluids may improve cell function, and possibly also organ function, in intensive-care patients. Electronic supplementary material The online version of this article (doi:10.1007/s00134-010-1873-x) contains supplementary material, which is available to authorized users. PMID:20397009

  9. Degradation of a Multilayer Insulation Due to a Seam and a Penetration

    NASA Technical Reports Server (NTRS)

    Sumner, I. E.

    1976-01-01

    The degradation of the thermal performance of a multilayer insulation due to the presence of a seam and a penetration was studied. The multilayer insulation had 30 aluminized Mylar radiation shields with silk net spacers. The seam, an offset butt joint, caused a heat input of 0.169 watt per meter in addition to the basic insulation thermal performance of 0.388 watt per square meter obtained before the installation of the butt joint. The penetration, a fiberglass tank support strut, provided a heat input (including the degradation of the insulation) of 0.543 watt in addition to the basic insulation thermal performance of 0.452 watt per square meter obtained before the penetration.

  10. Characterization of the OPAL obscurant penetrating LiDAR in various degraded visual environments

    NASA Astrophysics Data System (ADS)

    Trickey, Evan; Church, Philip; Cao, Xiaoying

    2013-05-01

    The OPAL obscurant penetrating LiDAR was developed by Neptec and characterized in various degraded visual environments (DVE) over the past five years. Quantitative evaluations of obscurant penetration were performed using the Defence RD Canada - Valcartier (DRDC Valcartier) instrumented aerosol chamber for obscurants such as dust and fog. Experiments were done with the sensor both at a standoff distance and totally engulfed in the obscurants. Field trials were also done to characterize the sensor in snow conditions and in smoke. Finally, the OPAL was also mounted on a Bell 412 helicopter to characterize its dust penetration capabilities, in environment such as Yuma Proving Ground. The paper provides a summary of the results of the OPAL evaluations demonstrating it to be a true "see through" obscurant penetrating LiDAR and explores commercial applications of the technology.

  11. Penetration of hydrogen peroxide and degradation rate of different bleaching products.

    PubMed

    Marson, F C; Gonçalves, R S; Silva, C O; Cintra, L T Â; Pascotto, R C; Santos, P H Dos; Briso, A L F

    2015-01-01

    This study's aim was to evaluate the degradation rate of hydrogen peroxide (H2O2) and to quantify its penetration in tooth structure, considering the residence time of bleaching products on the dental enamel. For this study, bovine teeth were randomly divided according to the bleaching product received: Opalescence Xtra Boost 38%, White Gold Office 35%, Whiteness HP Blue 35%, Whiteness HP Maxx 35%, and Lase Peroxide Sensy 35%. To analyze the degradation of H2O2, the titration of bleaching agents with potassium permanganate was used, while the penetration of H2O2 was measured via spectrophotometric analysis of the acetate buffer solution, collected from the artificial pulp chamber. The analyses were performed immediately as well as 15 minutes, 30 minutes, and 45 minutes after product application. The data of degradation rate of H2O2 were submitted to analysis of variance (ANOVA) and Tukey tests, while ANOVA and Fisher tests were used for the quantification of H2O2, at the 5% level. The results showed that all products significantly reduced the concentration of H2O2 activates at the end of 45 minutes. It was also verified that the penetration of H2O2 was enhanced by increasing the residence time of the product on the tooth surface. It was concluded that the bleaching gels retained substantial concentrations of H2O2 after 45 minutes of application, and penetration of H2O2 in the dental structure is time-dependent.

  12. Difficulties in Interpreting Ballast Degradation Level Estimates from Synthetic Ground-Penetrating Radar Data

    NASA Astrophysics Data System (ADS)

    Scanlan, K. M.; Hendry, M. T.; Martin, C. D.; Schmitt, D. R.

    2016-12-01

    As fine-grained particles accumulate within railway ballast, it becomes more susceptible to differential deformations, which leads to the loss of proper track alignment and an increased risk for car derailment. Methods for estimating the ballast degradation level from low-frequency (<1 GHz) ground-penetrating radar (GPR) measurements exist, but their applicability in a wide range of track foundation conditions has yet to be evaluated. This analysis, based on simulated GPR data, evaluates the sensitivity of these methods to changing ballast moisture contents, ballast thicknesses and subballast material types. The results highlight that small changes to the track foundation, indepedent of the concentration of degraded ballast, significantly alter the attenuation and reflectivity characteristics of the simualted GPR measurements. As such, ballast degraded to a certain level will manifest with different attenuation and reflectivity characteristics, limiting the ability to accurately and reliably detect these changes using GPR. Radar propagation velocities within the ballast are less influenced by changes in ballast depth and subballast material type. However, ambiguous propagation velocities are observed for certain ballast moisture contents and degradation levels; furthermore, velocities can only be calculated when the ballast thickness is known. These results suggest that while under certain circumstances, with additional information on the track foundation conditons, ballast degradation levels can be estimated from GPR data; in general, the complicated nature of GPR signals makes the quantificaion of ballast degradation levels difficult.

  13. Penetration enhancer-containing vesicles (PEVs) as carriers for cutaneous delivery of minoxidil.

    PubMed

    Mura, Simona; Manconi, Maria; Sinico, Chiara; Valenti, Donatella; Fadda, Anna Maria

    2009-10-01

    The aim of this work was to evaluate the ability of a few different penetration enhancers to produce elastic vesicles with soy lecithin and the influence of the obtained vesicles on in vitro (trans)dermal delivery of minoxidil. To this purpose, so-called Penetration Enhancer-containing Vesicles (PEVs) were prepared as dehydrated-rehydrated vesicles by using soy lecithin and different amounts of three penetration enhancers, 2-(2-ethoxyethoxy)ethanol (Transcutol), capryl-caproyl macrogol 8-glyceride (Labrasol), and cineole. Soy lecithin liposomes, without penetration enhancers, were used as control. Prepared formulations were characterized in terms of size distribution, morphology, zeta potential, and vesicle deformability. The influence of PEVs on (trans)dermal delivery of minoxidil was studied by in vitro diffusion experiments through newborn pig skin in comparison with traditional liposomes and ethanolic solutions of the drug also containing each penetration enhancer. A skin pre-treatment study using empty PEVs and conventional liposomes was also carried out. Results showed that all the used penetration enhancers were able to give more deformable vesicles than conventional liposomes with a good drug entrapment efficiency and stability. In vitro skin penetration data showed that PEVs were able to give a statistically significant improvement of minoxidil deposition in the skin in comparison with classic liposomes and penetration enhancer-containing drug ethanolic solutions without any transdermal delivery. Moreover, the most deformable PEVs, prepared with Labrasol and cineole, were also able to deliver to the skin a higher total amount of minoxidil than the PE alcoholic solutions thus suggesting that minoxidil delivery to the skin was strictly correlated to vesicle deformability, and therefore to vesicle composition.

  14. Study of tolnaftate release from fatty acids containing ointment and penetration into human skin ex vivo.

    PubMed

    Kezutyte, Toma; Drevinskas, Tomas; Maruska, Audrius; Rimdeika, Rytis; Briedis, Vitalis

    2011-01-01

    Five fatty acids (oleic, linoleic, myristic, lauric and capric) were incorporated in 10% (w/w) into ointment formulation and their influence on lipophilic model drug tolnaftate release in vitro and enhancing effect on tolnaftate penetration into epidermis and dermis of human skin ex vivo were investigated. The prepared ointments were tested for homogeneity, pH and theological properties. In vitro release studies and ex vivo skin penetration experiments were carried out using Hanson and Bronaugh-type flow-through diffusion cells, respectively. Tolnaftate cumulative amount liberated from semisolids was assayed using UV-Vis spectrophotometer. After in vitro skin penetration studies, appropriately extracted human skin layers were analyzed for tolnaftate content using a validated HPLC method. Statistical analysis revealed that release rate of tolnaftate from control ointment and ointments with fatty acids was not significantly different and only 7.34-8.98% of drug was liberated into an acceptor medium after 6 h. Tolnaftate amount penetrating into 1 cm2 of epidermis from ointments containing oleic, linoleic, myristic and lauric acids was significantly greater (p < 0.05) than from the control ointment. Penetration enhancing ratios for these fatty acids for tolnaftate penetration into epidermis ranged from 1.48 to 1.75. In conclusion, fatty acids did not increase the liberation of tolnaftate from ointment formulation, but demonstrated their enhancing effect on tolnaftate penetration into human epidermis in vitro. Results from in vitro release experiments do not suit for prediction of the situation in the skin in vitro, if chemical penetration enhancers are incorporated into the ointment formulation.

  15. Development of liposomes containing ethanol for skin delivery of temoporfin: characterization and in vitro penetration studies.

    PubMed

    Dragicevic-Curic, Nina; Scheglmann, Dietrich; Albrecht, Volker; Fahr, Alfred

    2009-11-01

    The aim of this study was to develop ethanol-containing (3.3-20%, w/v) liposomes loaded with temoporfin (mTHPC), which presents a highly hydrophobic photosensitizer with low percutaneous penetration, and to investigate their skin penetration enhancing effect. Characterization parameters of liposomes were measured by photon correlation spectroscopy, lamellarity was analyzed by cryo-electron microscopy and mTHPC-content in formulations was determined spectrofotometrically. In order to assess the stability of mTHPC-liposomes at 4 and 23 degrees C, at predetermined time intervals characterization parameters and mTHPC-content were measured. The in vitro skin penetration of mTHPC was investigated using human abdominal skin mounted in Franz cells. The results indicated that mTHPC-liposomes were of a small particle size, small polydispersity index, negative surface charge, unilamellar or oligolamellar, and of a spherical or oval shape. All liposomes were stable during 12 months' storage at 4 degrees C. Increasing the amount of ethanol in mTHPC-liposomes the skin deposition of mTHPC increased also. Liposomes without ethanol delivered the lowest amount of mTHPC into the skin, while liposomes containing 20% ethanol showed the highest penetration enhancement. In conclusion, mTHPC-liposomes containing 20% ethanol could be a promising tool for delivering temoporfin to the skin, which would be beneficial for the photodynamic therapy of cutaneous malignant or non-malignant diseases.

  16. The penetration of topically applied ointment containing hyaluronic acid in rabbit tissues.

    PubMed

    Birkenfeld, B; Parafiniuk, M; Bielecka-Grzela, S; Klimowicz, A; Piwowarska-Bilska, H; Mikołajczak, R; Listewnik, M H; Kurzejamska-Parafiniuk, M; Osowski, A; Byszewska-Szpocińska, E

    2011-01-01

    The properties of hyaluronic acid used for treatment of acute and chronic joint disease are known for many years and this compound is widely used both in humans and animals. To obtain a therapeutic effect of a certain drug, the appropriate concentration in the target organ or tissue is important. The application of labeled compounds is one of the frequently applied techniques to estimate drug penetration into the skin and other body tissues or organs. The aim of the study was to evaluate the penetration of hyaluronic acid labeled with I-131 through the skin and its distribution within the knee joint and other internal organs in rabbits after a topical application of an ointment containing hyaluronic acid. The experiment was performed on 22 albino rabbits divided into control and examined groups. Fifteen rabbits were exposed to the multicomponent ointment containing hyaluronic acid labeled with I-131. Time of exposure was 48 hours. Hyaluronate penetrated to a high degree into the examined tissues. No significant differences in terms of leg tissue activity were observed between a leg tissue exposed to labeled ointment and that unexposed, suggesting that after topical administration, the active component of the ointment is delivered to the joint via the blood stream. Hyaluronate applied topically penetrates through the skin into the rabbit tissues and organs and into the joint fluid of both legs (exposed and not exposed). This route of administration seems to be useful for this drug delivery and allows to avoid unnecessary side effects.

  17. Final Report Inspection of Aged/Degraded Containments Program.

    SciTech Connect

    Naus, Dan J; Ellingwood, B R; Oland, C Barry

    2005-09-01

    The Inspection of Aged/Degraded Containments Program had primary objectives of (1) understanding the significant factors relating corrosion occurrence, efficacy of inspection, and structural capacity reduction of steel containments and liners of reinforced concrete containments; (2) providing the United States Nuclear Regulatory Commission (USNRC) reviewers a means of establishing current structural capacity margins or estimating future residual structural capacity margins for steel containments, and concrete containments as limited by liner integrity; (3) providing recommendations, as appropriate, on information to be requested of licensees for guidance that could be utilized by USNRC reviewers in assessing the seriousness of reported incidences of containment degradation; and (4) providing technical assistance to the USNRC (as requested) related to concrete technology. Primary program accomplishments have included development of a degradation assessment methodology; reviews of techniques and methods for inspection and repair of containment metallic pressure boundaries; evaluation of high-frequency acoustic imaging, magnetostrictive sensor, electromagnetic acoustic transducer, and multimode guided plate wave technologies for inspection of inaccessible regions of containment metallic pressure boundaries; development of a continuum damage mechanics-based approach for structural deterioration; establishment of a methodology for reliability-based condition assessments of steel containments and liners; and fragility assessments of steel containments with localized corrosion. In addition, data and information assembled under this program has been transferred to the technical community through review meetings and briefings, national and international conference participation, technical committee involvement, and publications of reports and journal articles. Appendix A provides a listing of program reports, papers, and publications; and Appendix B contains a listing of

  18. Potential for containment leak paths through electrical penetration assemblies under severe accident conditions. [PWR; BWR

    SciTech Connect

    Sebrell, W.

    1983-07-01

    The leakage behavior of containments beyond design conditions and knowledge of failure modes is required for evaluation of mitigation strategies for severe accidents, risk studies, emergency preparedness planning, and siting. These studies are directed towards assessing the risk and consequences of severe accidents. An accident sequence analysis conducted on a Boiling Water Reactor (BWR), Mark I (MK I), indicated very high temperatures in the dry-well region, which is the location of the majority of electrical penetration assemblies. Because of the high temperatures, it was postulated in the ORNL study that the sealants would fail and all the electrical penetration assemblies would leak before structural failure would occur. Since other containments had similar electrical penetration assemblies, it was concluded that all containments would experience the same type of failure. The results of this study, however, show that this conclusion does not hold for PWRs because in the worst accident sequence, the long time containment gases stabilize to 350/sup 0/F. BWRs, on the other hand, do experience high dry-well temperatures and have a higher potential for leakage.

  19. Macrophage endosomes contain proteases which degrade endocytosed protein ligands.

    PubMed

    Diment, S; Stahl, P

    1985-12-05

    Rabbit alveolar macrophages rapidly internalize and degrade mannosylated bovine serum albumin (125I-mannose-BSA). Trichloroacetic acid-soluble degradation products appear in the cells as early as 6 min after uptake at 37 degrees C, and in the extracellular medium after 10 min. Incubation of endocytic vesicles containing this ligand in isotonic buffers at pH 7.4 + ATP resulted in intravesicular proteolysis, which was inhibited by monensin, nigericin, or ammonium chloride. At pH 5.0, degradation proceeded rapidly and was abolished by lysis of the vesicles with 0.1% Triton X-100. Readdition of lysosomes to the incubation mixture did not increase the rate of prelysosomal degradation. Proteolysis of 125I-mannose-BSA was optimal at pH 4.5, and inhibited by low concentrations of the cathepsin D inhibitor pepstatin A. After subcellular fractionation of the macrophages on Percoll gradients, 125I-mannose-BSA sedimented with prelysosomal vesicles and was not transported to secondary lysosomes. Addition of pepstatin A to extracellular medium during internalization of prebound 125I-mannose-BSA partially inhibited degradation of ligand, and resulted in transfer of undegraded 125I-mannose-BSA to lysosomes after 20 min. Using 125I-bovine serum albumin as a substrate for the protease in the presence of 0.1% Triton X-100, we have shown that as much as 36% of the total pepstatin A-sensitive activity sediments with nonlysosomal membranes. After intraendosomal iodination using lactoperoxidase, a labeled protease was isolated by affinity chromatography on pepstatin-agarose. The labeled protease, which had a subunit size of 46 kDa, was detected in endocytic vesicles after 5 min of internalization. These results suggest that a cathepsin D-like protease is responsible for the degradation of 125I-mannose-BSA in macrophages, and that this ligand is degraded in a prelysosomal vesicle.

  20. Degradation of dichlorvos containing wastewaters using sonochemical reactors.

    PubMed

    Golash, Nisharg; Gogate, Parag R

    2012-09-01

    The present work deals with application of sonochemical reactors for the degradation of dichlorvos containing wastewaters. The sonochemical reactor used in the work is a simple ultrasonic horn type operating at 20 kHz with a power rating of 270 W. The effect of different operating parameters such as operating pH, temperature and power density on the extent of degradation has been investigated initially followed by intensification studies using additives such as hydrogen peroxide, Fenton's reagent and CCl(4). It has been observed that low frequency sonochemical reactors can be effectively used for treatment of pesticide wastewaters and acidic conditions and optimum values of temperature and power dissipation favors the degradation of dichlorvos. The efficacy of sonochemical reactors can be further enhanced by using different additives at optimized loadings. Complete removal of the pesticide at the given loading has been obtained using an optimized combination of ultrasound and Fenton's chemistry. The controlling mechanism for the sonochemical degradation has been confirmed to be the free radical attack based on the studies involving radical scavengers. The novelty of the present work is clearly established as there have been no earlier studies dealing with degradation of dichlorvos pesticide using sonochemical reactors operating at low frequency which offers distinct advantage in terms of cost and the stability of the reactor. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Novel nail penetration enhancer containing vesicles "nPEVs" for treatment of onychomycosis.

    PubMed

    Bseiso, Eman A; Nasr, Maha; Sammour, Omaima A; Abd El Gawad, Nabaweya A

    2016-10-01

    The systemic treatment of onychomycosis has been hampered by the reported side effects of antifungals in addition to the limited blood circulation to the affected nails. Topical ungual treatment would circumvent the limitations of systemic onychomycosis treatment. Preparation and characterization of nail penetration enhancer containing nanovesicles (nPEVs) loaded with sertaconazole for topical treatment of onychomycosis. nPEVs were prepared using different nail penetration enhancers (N-acetyl-L-cysteine, thioglycolic acid, thiourea and ethanol) by the thin film hydration method, and characterized for their particle size, zeta potential, entrapment efficiency (EE%), elasticity, viscosity, physical stability and morphology. The selected nPEVs formula and the marketed Dermofix® cream were compared in terms of nail hydration, transungual drug uptake and antifungal activity against Trichophyton rubrum. N-acetyl-l-cysteine was the optimum nail penetration enhancer for incorporation within vesicles. nPEVs showed high EE% of sertaconazole ranging from 77 to 95%, a size ranging from 38-538 nm and a zeta potential ranging from +48 to +72 mV. The selected nPEVs formula displayed spherical morphology and good storage stability. Compared to the conventional marketed cream, the selected nPEVs formula showed 1.4-folds higher hydration and drug uptake enhancement into nail clippings. Furthermore, it showed significantly higher zone of inhibition for Trichophyton rubrum (20.9 ± 0.25 mm) than the marketed cream (11.6 ± 0.44 mm). Nail penetration enhancer containing nanovesicles (nPEVs) present a very promising option, worthy of clinical experimentation on onychomycotic patients.

  2. Biotransformation of nitrobenzene by bacteria containing toluene degradative pathways

    SciTech Connect

    Haigler, B.E.; Spain, J.C. )

    1991-11-01

    Nonpolar nitroaromatic compounds have been considered resistant to attack by oxygenases because of the electron withdrawing properties of the nitro group. The authors have investigate the ability of seven bacterial strains containing toluene degradative pathways to oxidize nitrobenzene. Cultures were induced with toluene vapor prior to incubation with nitrobenzene, and products were identified by high-performance liquid chromatography and gas chromatography-mass spectrometry. Pseudomonas cepacia G4 and a strain of Pseudomonas harboring the TOL plasmid (pTN2) did not transform nitrobenzene. Cells of Pseudomonas putida F1 and Pseudomonas sp. strain JS150 converted nitrobenzene to 3-nitrocatechol. Transformation of nitrobenzene in the presence of {sup 18}O{sub 2} indicated that the reaction in JS150 involved the incorporation of both atoms of oxygen in the 3-nitrocatechol, which suggests a dioxygenase mechanism. P. putida 39/D, a mutant strain of P. putida F1, converted nitrobenzene to a compound tentatively identified as cis-1, 2-dihydroxy-3-nitrocyclohexa-3, 5-diene. This compound was rapidly converted to 3-nitrocatechol by cells of strain JS150. Cultures of Pseudomonas mendocina KR-1 converted nitrobenzene to a mixture of 3- and 4-nitrophenol (10 and 63%, respectively). Pseudomonas pickettii PKO1 converted nitrobenzene to 3- and 4-nitrocatechol via 3- and 4-nitrophenol. The nitrocatechols were slowly degraded to unidentified metabolites. Nitrobenzene did not serve as an inducer for the enzymes that catalyzed its oxidation.

  3. Inspection of a large concrete block containing embedded defects using ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Eisenmann, David; Margetan, Frank J.; Koester, Lucas; Clayton, Dwight

    2016-02-01

    Ground penetrating radar (GPR), also known as impulse response radar, was used to examine a thick concrete block containing reinforcing steel bars (rebar) and embedded defects. The block was located at the University of Minnesota, measured approximately 7 feet tall by 7 feet wide by 40 inches deep, and was intended to simulate certain aspects of a concrete containment wall at a nuclear power plant. This paper describes the measurements that were made and various analyses of the data. We begin with a description of the block itself and the GPR equipment and methods used in our inspections. The methods include the application of synthetic aperture focusing techniques (SAFT). We then present and discuss GPR images of the block's interior made using 1600-MHz, 900-MHz, and 400-MHz antennas operating in pulse/echo mode. A number of the embedded defects can be seen, and we discuss how their relative detectability can be quantified by comparison to the response from nearby rebar. We next discuss through-transmission measurements made using pairs of 1600-MHz and 900-MHz antennas, and the analysis of that data to deduce the average electromagnetic (EM) wave speed and attenuation of the concrete. Through the 40-inch thickness, attenuation rises approximately linearly with frequency at a rate near 0.7 dB/inch/GHz. However, there is evidence that EM properties vary with depth in the block. We conclude with a brief summary and a discussion of possible future work.

  4. Degradation Mechanisms of SOFC Anodes in Coal Gas Containing Phosphorus

    SciTech Connect

    Marina, Olga A.; Coyle, Christopher A.; Thomsen, Edwin C.; Edwards, Danny J.; Coffey, Greg W.; Pederson, Larry R.

    2010-01-22

    The interaction of phosphorus in synthetic coal gas with the nickel-based anode of solid oxide fuel cells has been investigated. Tests with both anode-supported and electrolyte-supported button cells were performed at 700 to 800oC in synthetic coal gas containing 0.5 to 10 ppm phosphorus, introduced as phosphine. Two primary modes of degradation were observed. The most obvious was the formation of a series of bulk nickel phosphide phases, of which Ni3P, Ni5P2, Ni12P5 and Ni2P were identified. Phosphorus was essentially completely captured by the anode, forming a sharp boundary between converted and unconverted anode portions. These products partially coalesced into large grains, which eventually affected electronic percolation through the anode support. Thermodynamic calculations predict that formation of the first binary nickel phosphide phase is possible at sub-parts per billion concentrations in coal gas at temperatures relevant to fuel cell operation. A second mode of degradation is attributed to surface diffusion of phosphorus to the active anode/electrolyte interface to form an adsorption layer. Direct evidence for the presence of such an adsorption layer on nickel was obtained by surface spectroscopies on fracture surfaces. Further, cell performance losses were observed well before the entire anode was converted to bulk nickel phosphide. Impedance spectroscopy revealed that these losses were primarily due to growth in electrodic resistance, whereas large ohmic increases were visible when the entire anode was converted to nickel phosphide phases. The rate of resistance growth for anode-supported cells showed a very low dependence on phosphorus concentration, attributed to phosphorus activity control within the anode by bulk nickel phosphide products.

  5. Sequential monitoring of burials containing large pig cadavers using ground-penetrating radar.

    PubMed

    Schultz, John J; Collins, Mary E; Falsetti, Anthony B

    2006-05-01

    Ground-penetrating radar (GPR) was used to monitor 12 pig burials in Florida, each of which contained a large pig cadaver. Six of the cadavers were buried in sand at a depth of 0.50-0.60 m, and the other six were buried at a depth of 1.00-1.10 m and were in contact with the upper surface of a clay horizon. Control excavations with no pig internment were also constructed as blank graves and monitored with GPR. The burials were monitored with GPR for durations of either 12-13 or 21-21.5 months when they were then excavated to correlate the decomposition state of the cadaver with the GPR imagery. Overall, cadavers in sand were easily detected for the duration of this study at 21.5 months, even when completely skeletonized. Conversely, in clay it became increasingly difficult to image the pig cadavers over the first year of burial, even when they still retained extensive soft tissue structures.

  6. Sequential monitoring of burials containing small pig cadavers using ground penetrating radar.

    PubMed

    Schultz, John J

    2008-03-01

    Ground-penetrating radar (GPR) was used to monitor 12 pig burials in Florida, each of which contained a small pig cadaver. Six of the cadavers were buried in sand at a depth of 0.50-0.60 m, and the other six were buried in sand at a depth of 1.00-1.10 m to represent deep and shallow burials that are generally encountered in forensic scenarios. Four control excavations with no pig interment were also constructed as blank graves and monitored with GPR. The burials were monitored for durations of either 13 or 21 months, and were then excavated to correlate the decomposition state of the cadaver with the GPR imagery. Overall, this study demonstrated that it may be difficult to detect small cadavers buried in sand soon after they are skeletonized because the area surrounding the body, or the grave, may not provide a strong enough contrasting area to be detected by GPR when compared to that of the surrounding undisturbed soil. Also, depth of burial appears to influence grave detection because bodies that are buried at deeper depths may be detected for a longer period of time due to reduced decomposition rates.

  7. Design of aromatic-containing cell-penetrating peptide mimics with structurally modified π electronics.

    PubMed

    deRonde, Brittany M; Birke, Alexander; Tew, Gregory N

    2015-02-09

    Cell-penetrating peptides (CPPs) and their synthetic mimics (CPPMs) represent a class of molecules that facilitate the intracellular delivery of various cargo. Previous studies indicated that the presence of aromatic functionalities improved CPPM activity. Given that aromatic functionalities play prominent roles in membrane biology and participate in various π interactions, we explored whether these interactions could be optimized for improved CPPM activity. CPPMs were synthesized by ring-opening metathesis polymerization by using monomers that contained aromatic rings substituted with electron-donating and electron-withdrawing groups and covered an electrostatic potential range from -29.69 to +15.57 kcal mol(-1) . These groups altered the quadrupole moments of the aromatic systems and were used to test if such structural modifications changed CPPM activity. CPPMs were added to dye-loaded vesicles and the release of carboxyfluorescein was monitored as a function of polymer concentration. Changes in the effective polymer concentration to release 50% of the dye (effective concentration, EC50 ) were monitored. Results from this assay showed that the strength of the electron-donating and electron-withdrawing groups incorporated in the CPPMs did not alter polymer EC50 values or activity. This suggests that other design parameters may have a stronger impact on CPPM activity. In addition, these results indicate that a wide range of aromatic groups can be incorporated without negatively impacting polymer activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Calorimeter testing of thermal degradation of multilayer insulation due to the presence of penetrations

    NASA Astrophysics Data System (ADS)

    Johnson, W. L.; Kelly, A. O.; Heckle, K. W.; Jumper, K. M.; Fesmire, J. E.

    2014-01-01

    Cryogenic multilayer insulation (MLI) has been studied thoroughly over the last 60 years. Numerous tank and calorimeter tests have been performed using many different insulation approaches. However, a large majority of these tests have been on ideal or nearly ideal insulation systems. There are several important factors such as seams or penetrations through the insulation that can drive up the heat load on the entire system, for full system design, these factors must be accounted for. Several attempts have been made to identify the performance losses due to structural integration with a real system. These specific cases were tied to specific programs and configuration dependent. In an effort to understand the complex heat transfer mechanisms surrounding such systems, a calorimeter testing program coupled with thermal modeling of the experimental results tests was performed. A new boil-off calorimeter was developed for measurement of the two dimensional heat transfer effects. The corresponding methodology was devised to calculate the thermal losses within the MLI due to the presence of the penetration and determine the affected area within the blanket. The test matrix included multiple integration methods, materials, penetration materials, and penetrations sizes. Results of the testing were used to anchor a thermal model of the system that allows for characterization of a wider range of situations.

  9. Nature of the Penetration Barrier in Escherichia coli K-12: Effect of Macromolecular Inhibition on Penetrability in Strains Containing the envA Gene

    PubMed Central

    Normark, Staffan; Westling, Britta

    1971-01-01

    The envA mutation in Escherichia coli K-12, which maps at 1.5 min, was previously shown to mediate sensitivity to gentian violet as well as to several antibiotics. Moreover, strains containing the envA gene were recently found to be lysed by lysozyme in the absence of ethylenediaminetetraacetate. It is here reported that the envA mutation mediates an increased uptake of gentian violet. The uptake of the dye was markedly affected by growth with different antibiotics interfering with macromolecular synthesis. Amino acid starvation of a strain containing envA with a stringent control of ribonucleic acid (RNA) synthesis resulted in a decreased uptake of gentian violet. However, no decrease in dye uptake was found during starvation in an envA transductant with a relaxed control of RNA synthesis. Inhibition of deoxyribonucleic acid (DNA) synthesis by nalidixic acid decreased the uptake of gentian violet of envA cells and, in addition, rendered the cells insensitive to the lytic action of lysozyme. Chloramphenicol treatment increased penetrability in wild-type and starved envA cells. In most instances, this effect of chloramphenicol was prevented by selectively interfering with DNA or RNA synthesis. A coordinate regulation of nucleic acid synthesis and penetrability is suggested. PMID:4941566

  10. Analysis of the penetration of a caffeine containing shampoo into the hair follicles by in vivo laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Lademann, J.; Richter, H.; Schanzer, S.; Klenk, A.; Sterry, W.; Patzelt, A.

    2010-02-01

    In previous in vitro investigations, it was demonstrated that caffeine is able to stimulate the hair growth. Therefore, a penetration of caffeine into the hair follicle is necessary. In the present study, in vivo laser scanning microscopy (LSM) was used to investigate the penetration and storage of a caffeine containing shampoo into the hair follicles. It was shown that a 2-min contact time of the shampoo with the skin was enough to accumulate significant parts of the shampoo in the hair follicles. A penetration of the shampoo up to a depth of approx. 200 μm could be detected, which represents the detection limit of the LSM. At this depth, the close network of the blood capillaries surrounding the hair follicles commences. Even after 24 h, the substance was still detectable in the hair follicles. This demonstrates the long-term reservoir function of the hair follicles for topically applied substances such as caffeine.

  11. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    SciTech Connect

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. ); Bullen, D.B. )

    1988-04-01

    Three iron- to nickel-based austenitic alloys (Types 304L and 316L stainless steels and Alloy 825) are being considered as candidate materials for the fabrication of high-level radioactive-waste containers. Waste will include fuel assemblies from reactors as well as high-level waste in borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides in the repository will result in the generation of substantial heat and in fluences of gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including atmospheric oxidation; uniform aqueous phase corrosion; pitting; crevice corrosion; sensitization and intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This report is an analysis of data relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of the three austenitic candidate alloys. The candidates are compared in terms of their susceptibilities to these forms of corrosion. Although all three candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these types of localized corrosion (LC); such resistance is important because pits can penetrate the metal and serve as crack initiation sites. Both Types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented in Alloy 825 under comparable conditions. Gamma radiation has been found to enhance SCC in Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while the effects of microbiologically induced corrosion have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. 211 refs., 49 figs., 10 tabs.

  12. Stress analysis of the liner and liner anchorage system near penetrations in a reinforced concrete reactor containment

    SciTech Connect

    Weatherby, J.R.

    1989-01-01

    An overpressurization experiment was conducted on a scale-model of a reinforced concrete containment building. The test was terminated when tears formed in the steel liner. Virtually all leakage occurred through a large tear that propagated along the edge of a thickened insert plate that surrounded a piping penetration. This paper describes the results of a post-test finite element analysis of this region. Results of the analysis indicate that the large tear initiated due to high strains produced by a stud anchor. The results of the analysis also suggest that a relatively simple analytical technique can be used to estimate the pressure at which tears will initiate near penetrations in lined containment structures. 5 refs., 8 figs., 1 tab.

  13. Effect of Penetration Enhancer Containing Vesicles on the Percutaneous Delivery of Quercetin through New Born Pig Skin

    PubMed Central

    Chessa, Maura; Caddeo, Carla; Valenti, Donatella; Manconi, Maria; Sinico, Chiara; Fadda, Anna Maria

    2011-01-01

    Quercetin (3,3′,4′,5,7-pentahydroxyflavone) exerts multiple pharmacological effects: anti-oxidant activity, induction of apoptosis, modulation of cell cycle, anti-mutagenesis, and anti-inflammatory effect. In topical formulations quercetin inhibits oxidative skin damage and the inflammatory processes induced by solar UV radiation. In this work, quercetin (2 mg/mL) was loaded in vesicular Penetration Enhancer containing Vesicles (PEVs), prepared using a mixture of lipids (Phospholipon® 50, P50) and one of four selected hydrophilic penetration enhancers: Transcutol® P, propylene glycol, polyethylene glycol 400, and Labrasol® at the same concentration (40% of water phase). Photon Correlation Spectroscopy results showed a mean diameter of drug loaded vesicles in the range 80–220 nm. All formulations showed a negative surface charge and incorporation efficiency in the range 48–75%. Transmission Electron Microscopy confirmed that size and morphology varied as a function of the used penetration enhancer. The influence of PEVs on ex vivo quercetin (trans)dermal delivery was evaluated using Franz-type diffusion cells, new born pig skin and Confocal Laser Scanning Microscopy. Results showed that drug delivery is affected by the penetration enhancer used in the PEVs' formulation. PMID:24310593

  14. Gel formulations containing catanionic vesicles composed of alprenolol and SDS: effects of drug release and skin penetration on aggregate structure.

    PubMed

    Dew, Noel; Edwards, Katarina; Eriksson, Jonny; Edsman, Katarina; Björk, Erik

    2012-01-01

    To fully utilize the extended contact time of gel formulations a novel formulation with drug containing catanionic aggregates offering prolonged drug release and skin penetration were investigated. This study aimed to further explore the drug release process from catanionic vesicles in gels. Catanionic vesicles were formed from alprenolol and sodium dodecyl sulphate. Physical gels composed of catanionic vesicles and a SoftCAT polymer were used as well as covalent Carbopol gels. Drug release was measured in vitro using a modified USP paddle method and the skin penetration was studied using dermatomized pig ear skin mounted in horizontal Ussing chambers. The aggregate structure was visualized with cryo-TEM during the drug release and skin penetration process. The study results show that catanionic vesicles are present in the formulations throughout the drug release process and during the clinically relevant skin application time. Hence, the decreased skin penetration rate stems from the prolonged release of drug substance from the gels. The rheological investigation shows that the gel structure of the physically cross-linked gels is maintained even as the drug substance is released and the gel volume is decreased. These findings indicate that the applicability of formulations like these is a future possibility. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Thermal degradation of multilayer insulation due to the presence of penetrations

    NASA Astrophysics Data System (ADS)

    Johnson, W. L.; Kelly, A. O.; Fesmire, J. E.

    2014-01-01

    Invented in the 1950s, cryogenic multilayer insulation (MLI) continues to be studied, tested, and analyzed as it represents a complex system that is integral with the total system to be insulated. Numerous tank and calorimeter tests have been performed using many different insulation approaches. Many different variables have been tested and documented, mainly within the insulation system itself. There are several factors in insulation application that can drive up the heat load on the entire system. These include the treatment of insulation seams, instrumentation wires running through the insulation, and the integration of the insulation with the structures and fluids. Several attempts have been made to identify the performance losses due to structural integration with a real system. Due to the nature of MLI, these were tied to specific programs and configuration dependent. In an effort to understand the complex heat transfer mechanisms surrounding such systems, a series of calorimeter testing coupled with thermal modeling of the calorimeter tests was put into place. Testing showed that a buffer of micro-fiberglass material such as Cryolite is a robust method of closing out MLI penetrations. Additionally, a validated thermal model was used to develop parametric analysis far beyond the limitations of the calorimeter testing. This paper presents the methodology and approach, with experimental data providing the basis for developing the thermal model and its results for applicability to future design cases.

  16. A quantitative analysis of aerosols inside an armored vehicle perforated by a kinetic energy penetrator containing tungsten, nickel, and cobalt.

    PubMed

    Gold, Kenneth; Cheng, Yung Sung; Holmes, Thomas D

    2007-04-01

    These tests were conducted to develop a database that could be used to assess risks to soldiers from exposure to aerosolized metallic particulates when the crew compartment of an Abrams tank is perforated by a kinetic energy penetrator. Quantitative data are reported for aerosols produced by kinetic energy penetrators containing tungsten, nickel, and cobalt. The following are addressed: (1) concentrations and rates of particle settling inside the vehicle, (2) particle size distribution, (3) inhalable and respirable particulates, (4) distribution of aerosol particles by mass, and (5) particle shapes. The scenario described in this report simulates a rare occurrence. The lessons learned, however, highlight a requirement for developing protocols for analyses of metals in body fluids and urine as soon as practical, and also for implementing targeted postdeployment medical surveillance programs that monitor both body burden for respired metals and pulmonary function.

  17. Degradation and Failure Characteristics of NPP Containment Protective Coating Systems

    SciTech Connect

    Sindelar, R.L.

    2001-04-10

    Nuclear power plants (NPPs) must ensure that the emergency core cooling system (ECCS) or safety-related containment spray system (CSS) remains capable of performing its design safety function throughout the life of the plant. This requires ensuring that long-term core cooling can be maintained following a postulated loss-of-coolant accident (LOCA). Adequate safety operation can be impaired if the protective coatings which have been applied to the concrete and steel structures within the primary containment fail, producing transportable debris which could then accumulate on BWR ECCS suction strainers or PWR ECCS sump debris screens located within the containment. This document will present the data collected during the investigation of coating specimens from plants.

  18. Multiple-projectile penetrating neck injury from a modified nail-containing gas pistol.

    PubMed

    Pazardzhikliev, Dimitar Dimitrov

    2014-09-01

    Penetrating neck injuries result from missiles and stab wounds. A gas pistol is a non-lethal weapon for self-defence. We present a case where the use of a modified gun led to multiple injuries in a single shot. Four projectiles were embedded in the neck, one in the larynx and three in the cervical spine. The first was removed via a combined external and endoscopic approach, while the rest were put on follow-up. The reported case shows that damage from modified gas pistols, although rarely life threatening, may cause long term discomfort and diminished quality of life.

  19. Degradation and Failure Characteristics of NPP Containment Protective Coating Systems

    SciTech Connect

    Sindelar, R.L.

    2000-12-01

    A research program to investigate the performance and potential for failure of Service Level I coating systems used in nuclear power plant containment is in progress. The research activities are aligned to address phenomena important to cause failure as identified by the industry coatings expert panel.

  20. Evaluation of Skin Permeation and Analgesic Activity Effects of Carbopol Lornoxicam Topical Gels Containing Penetration Enhancer

    PubMed Central

    Al-Suwayeh, Saleh A.; Taha, Ehab I.; Al-Qahtani, Fahad M.; Ahmed, Mahrous O.; Badran, Mohamed M.

    2014-01-01

    The current study was designed to develop a topical gel formulation for improved skin penetration of lornoxicam (LOR) for enhancement of its analgesic activity. Moreover, the effect of different penetration enhancers on LOR was studied. The LOR gel formulations were prepared by using hydroxylpropyl methylcellulose (HPMC) and carbopol. The carbopol gels in presence of propylene glycol (PG) and ethanol were developed. The formulated gels were characterized for pH, viscosity, and LOR release using Franz diffusion cells. Also, in vitro skin permeation of LOR was conducted. The effect of hydroxypropyl β-cyclodextrin (HP β-CD), beta-cyclodextrin (β-CD), Tween 80, and oleic acid on LOR permeation was evaluated. The optimized LOR gel formulation (LORF8) showed the highest flux (14.31 μg/cm2/h) with ER of 18.34 when compared to LORF3. Incorporation of PG and HP β-CD in gel formulation (LORF8) enhanced the permeation of LOR significantly. It was observed that LORF3 and LORF8 show similar analgesic activity compared to marketed LOR injection (Xefo). This work shows that LOR can be formulated into carbopol gel in presence of PG and HP β-CD and may be promising in enhancing permeation. PMID:25045724

  1. Degradation mode surveys of high performance candidate container materials

    SciTech Connect

    Gdowski, G.E.; McCright, R.D.

    1990-12-01

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project`s high-level radioactive waste disposal containers. Nickel-chromium-molybdenum alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion and of how various parameters affect it will be necessary for adequate performance assessment of candidate container materials. Examples of some of the concerns involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition, concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250{degree}C) are presented. Also some mechanistic considerations of localized corrosion are given. 45 refs., 1 tab.

  2. Degradation and Failure Characteristics of NPP Containment Protective Coating Systems

    SciTech Connect

    Sindelar, R.L.

    2001-02-22

    A research program to investigate the performance and potential for debris formation of Service Level I coating systems used in nuclear power plant containment is being performed at the Savannah River Technology Center. The research activities are aligned to address phenomena important to cause coating disbondment as identified by the Industry Coatings Expert Panel. The period of interest for performance covers the time from application of the coating through 40 years of service, followed by a medium-to-large break loss-of-coolant accident scenario, which is a design basis accident (DBA) scenario. The interactive program elements are described in this report and the application of these elements to evaluate the performance of the specific coating system of Phenoline 305 epoxy-phenolic topcoat over Carbozinc 11 primer on a steel substrate. This system is one of the predominant coating systems present on steel substrates in NPP containment.

  3. Catalytic Degradation of Benzene over Nanocatalysts containing Cerium and Manganese.

    PubMed

    Wang, Zhen; Deng, Yuzhou; Shen, Genli; Akram, Sadia; Han, Ning; Chen, Yunfa; Wang, Qi

    2016-10-01

    A Ce-Mn composite oxide possessing a rod-like morphology (with a fixed molar ratio of Ce/Mn=3:7) was synthesized through a hydrothermal method. Mn ions were doped into a CeO2 framework to replace Ce ions, thereby increasing the concentration of oxygen vacancies. The formation energies of O vacancies for the Ce-Mn composite oxide were calculated by applying density functional theory (DFT). The data showed that it was easier to form an O vacancy in the composite. The catalytic behavior of the Ce-Mn composite oxide for benzene degradation was researched in detail, which exhibited a higher activity than the pure phases. Based on this, the Ce-Mn composite oxide was chosen as a supporter to load PdO nanoparticles. The activity was enhanced further compared with that of the supporter alone (for the supporter, the reaction rate R214 °C=0.68×10(-4) mol gcat(-1) s(-1) and apparent activation energy Ea=12.75 kJ mol(-1); for the supporting catalyst, R214 °C=1.46×10(-4) mol gcat(-1) s(-1), Ea=10.91 kJ mol(-1)). The corresponding catalytic mechanism was studied through in situ Raman and FTIR spectroscopy, which indicated that the process of benzene oxidation was related to different types of oxygen species existing at the surface of the catalysts.

  4. Catalytic Degradation of Benzene over Nanocatalysts containing Cerium and Manganese

    PubMed Central

    Wang, Zhen; Deng, Yuzhou; Shen, Genli; Akram, Sadia; Han, Ning

    2016-01-01

    Abstract A Ce–Mn composite oxide possessing a rod‐like morphology (with a fixed molar ratio of Ce/Mn=3:7) was synthesized through a hydrothermal method. Mn ions were doped into a CeO2 framework to replace Ce ions, thereby increasing the concentration of oxygen vacancies. The formation energies of O vacancies for the Ce–Mn composite oxide were calculated by applying density functional theory (DFT). The data showed that it was easier to form an O vacancy in the composite. The catalytic behavior of the Ce–Mn composite oxide for benzene degradation was researched in detail, which exhibited a higher activity than the pure phases. Based on this, the Ce–Mn composite oxide was chosen as a supporter to load PdO nanoparticles. The activity was enhanced further compared with that of the supporter alone (for the supporter, the reaction rate R 214 °C=0.68×10−4 mol gcat −1 s−1 and apparent activation energy E a=12.75 kJ mol−1; for the supporting catalyst, R 214 °C=1.46×10−4 mol gcat −1 s−1, E a=10.91 kJ mol−1). The corresponding catalytic mechanism was studied through in situ Raman and FTIR spectroscopy, which indicated that the process of benzene oxidation was related to different types of oxygen species existing at the surface of the catalysts. PMID:27777843

  5. Alumina plate containing photosystem I reaction center complex oriented inside plate-penetrating silica nanopores.

    PubMed

    Kamidaki, Chihiro; Kondo, Toru; Noji, Tomoyasu; Itoh, Tetsuji; Yamaguchi, Akira; Itoh, Shigeru

    2013-08-22

    The photosynthetic photosystem I reaction center complex (PSI-RC), which has a molecular diameter of 21 nm with 100 pigments, was incorporated into silica nanopores with a 100-nm diameter that penetrates an alumina plate of 60-μm thickness to make up an inorganic-biological hybrid photocell. PSI-RCs, purified from a thermophilic cyanobacterium, were stable inside the nanopores and rapidly photoreduced a mediator dye methyl viologen. The reduced dye was more stable inside nanopores suggesting the decrease of dissolved oxygen. The analysis by a cryogenic electron spin paramagnetic resonance indicated the oriented arrangement of RCs inside the 100-nm nanopores, with their surface parallel to the silica wall and perpendicular to the plane of the alumina plate. PSI RC complex in the semicrystalline orientation inside silica nanopores can be a new type of light energy conversion unit to supply strong reducing power selectively to other molecules inside or outside nanopores.

  6. Degradation and failure characteristics of NPP containment protective coating systems

    SciTech Connect

    Sindelar, R.L.

    2000-03-30

    A research program to investigate the performance and potential for failure of Service Level 1 coating systems used in nuclear power plant containment is in progress. The research activities are aligned to address phenomena important to cause failure as identified by the industry coatings expert panel. The period of interest for performance covers the time from application of the coating through 40 years of service, followed by a medium-to-large break loss-of-coolant accident scenario, which is a design basis accident (DBA) scenario. The interactive program elements are discussed in this report and the application of these elements to the System 5 coating system (polyamide epoxy primer, carbon steel substrate) is used to evaluate performance.

  7. Effect of vehicles and enhancers on the in vitro skin penetration of aspalatone and its enzymatic degradation across rat skins.

    PubMed

    Gwak, H S; Chun, I K

    2001-12-01

    The feasibility of skin penetration was studied for aspalatone (AM, acetylsalicylic acid maltol ester), a novel antithrombotic agent. In this study, hairless mouse dorsal skins were used as a model to select composition of vehicle and AM. Based on measurements of solubility and partition coefficient, the concentration of PG that showed the highest flux for AM across the hairless mouse skin was found to be 40%. The cumulative amount permeated at 48 h, however, appear inadequate, even when the PG concentration was employed. To identify a suitable absorption enhancer and its optimal concentration for AM, a number of absorption enhancers and a variety of concentration were screened for the increase in transdermal flux of AM. Amongst these, linoleic acid (LOA) at the concentration of 5% was found to have the largest enhancement factor (i.e., 132). However, a further increase in AM flux was not found in the fatty acid concentration greater than 5%, indicating the enhancement effect is in a bell-shaped curve. In a study of the effect of AM concentration on the permeation, there was no difference in the permeation rate between 0.5 and 1% for AM, below its saturated concentration. At the donor concentration of 2%, over the saturated condition, the flux of AM was markedly increased. A considerable degradation of AM was found during permeation studies, and the extent was correlated with protein concentrations in the epidermal and serosal extracts, and skin homogenates. In rat dorsal skins, the protein concentration decreased in the rank order of skin homogenate > serosal extract > epidermal extract. Estimated first order degradation rate constants were 6.1 5 +/- 0.14, 0.57 +/- 0.02 and 0.011 +/- 0.004 h(-1) for skin homogenate, serosal extract and epidermal extract, respectively. Therefore, it appeared that AM was hydrolyzed to some extent into salicylmaltol by esterases in the dermal and subcutaneous tissues of skin. Taken together, our data indicated that transdermal

  8. Drug delivery with nanospherical supramolecular cell penetrating peptide-taxol conjugates containing a high drug loading.

    PubMed

    Tian, Ran; Wang, Huaimin; Niu, Ruifang; Ding, Dan

    2015-09-01

    Supramolecular nanostructures via small molecule self-assembly hold great promise for controlled delivery of hydrophobic anticancer drugs. Particularly, taxol has recently been discovered to possess excellent self-assembly property, which may provide new opportunities to develop a new class of functional supramolecular nanomaterials for drug delivery application. A cell penetrating peptide (CPP)-taxol conjugate (Taxol-CPP) was designed and synthesized. The self-assembling property of Taxol-CPP was investigated and the resultant nanomaterials were well characterized. Subsequently, the cytotoxicity of the Taxol-CPP after self-assembly against HepG2 cancer cells was evaluated. It is found that the Taxol-CPP possesses a high drug loading of 26.4% in each molecule, which is able to self-assemble into supramolecular nanospheres. By taking advantages of the self-assembly ability of taxol, Taxol-CPP supramolecular nanospheres with a mean size of around 130 nm can be obtained, composed of only the functional peptide (CPP) and the drug (taxol). Furthermore, we have demonstrated that the Taxol-CPP nanospheres do not compromise the taxol's potency, which can also be utilized as the carriers for co-delivery of another anticancer drug (doxorubicin). Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Percutaneous penetration of silver from a silver containing garment in healthy volunteers and patients with atopic dermatitis.

    PubMed

    Pluut, Olivier A; Bianco, Carlotta; Jakasa, Ivone; Visser, Maaike J; Krystek, Petra; Larese-Filon, Francesca; Rustemeyer, Thomas; Kezic, Sanja

    2015-06-01

    Human data on dermal absorption of silver under "in use" scenario are scarce which hampers health risk assessment. The main objective of the present study was to determine percutaneous penetration of silver after dermal exposure to silver containing garment in healthy individuals and atopic dermatitis (AD) patients. Next to assess pro-inflammatory effect of silver in the skin. Healthy subjects (n=15) and patients with AD (n=15) wore a sleeve containing 3.6% (w/w) silver on their lower arms for 8h during 5 consecutive days. The percutaneous penetration parameters were deduced from the silver concentration-depth profiles in the stratum corneum (SC) collected by adhesive tapes. Furthermore, silver was measured in urine samples collected before and after exposure. Inflammatory response was assessed by measuring IL-1α and IL-1RA in the exposed and non-exposed skin sites. Dermal flux of silver in healthy subjects and AD patients was respectively 0.23 and 0.20 ng/cm(2)/h. The urine silver concentrations showed no increase after exposure. Furthermore, exposure to silver did not lead to the changes in the profiles of IL-1α and IL-1RA. Dermal absorption of silver under "real life scenario" was lower than the current reference dose. Furthermore, dermal exposure did not lead to altered expression of inflammatory IL-1 cytokines in the skin.

  10. Development of helix-stabilized cell-penetrating peptides containing cationic α,α-disubstituted amino acids as helical promoters.

    PubMed

    Yamashita, Hiroko; Misawa, Takashi; Oba, Makoto; Tanaka, Masakazu; Naito, Mikihiko; Kurihara, Masaaki; Demizu, Yosuke

    2017-03-15

    Cell-penetrating peptides (CPP) have attracted many scientists' attention as intracellular delivery tools due to their high cargo molecule transportation efficiency and low cytotoxicity. Therefore, in many research fields CPP, such as HIV-Tat and oligoarginine (Rn), are used to deliver hydrophilic drugs and biomolecules, including proteins, DNA, and RNA. We designed four types of CPP that contained cationic α,α-disubstituted amino acids (Api(C2Gu) and Api(C4Gu)) as helical promoters; i.e., 1-4 [FAM-β-Ala-(l-Arg-l-Arg-Xaa)3-(Gly)3-NH2 (1: Xaa=Api(C2Gu), 2: Xaa=Api(C4Gu)), 3: FAM-β-Ala-(l-Arg)8-Api(C2Gu)-(Gly)3-NH2, and 4: FAM-β-Ala-(l-Arg)5-Api(C2Gu)-(l-Arg)2-Api(C2Gu)-(Gly)3-NH2], and investigated their preferred secondary structures and cell membrane-penetrating ability. As a result, we found that the permeation efficiency of the CPP was affected by the number of helical promoters in their sequences. Specially, peptide 1, which contained three Api(C2Gu) residues, formed a stable helical structure and passed through the cell membrane more efficiently than the other peptides. Moreover, it was demonstrated that the spatial arrangement of the peptides' side chains also influenced their permeability and the helical stabilization of their main chains.

  11. In vitro degradation and erosion of degradable, segmented polyurethanes containing an amino acid-based chain extender.

    PubMed

    Skarja, G A; Woodhouse, K A

    2001-01-01

    In vitro degradation and erosion of novel, degradable segmented polyurethanes containing a phenylalanine diester chain extender were investigated by exposing the polymers to buffer. chymotrypsin, and trypsin solutions for up to 28 days. Polyurethane degradation and erosion were monitored by gravimetry, scanning electron microscopy (SEM), and gel permeation chromatography (GPC) and compared to a control polyurethane. Polyurethanes were synthesized using two different soft segments (polycaprolactone diol and polyethylene oxide) of variable molecular weight. Inclusion of the phenylalanine-based chain extender resulted in an increased susceptibility to enzyme-mediated, but not buffer-mediated, erosion in comparison to the control polyurethane. SEM analysis indicated that enzyme-mediated erosion proceeded via a surface-limited mechanism resulting in a progressive removal of material from the surface inwards with time. The magnitude of degradation and erosion was highly variable and was dependent on soft segment type and molecular weight. The range of degradation rates, as well as physicochemical properties, makes these polyurethanes potentially useful for a wide range of biomedical applications.

  12. Heterogeneous photocatalytic degradation of phenanthrene in surfactant solution containing TiO2 particles.

    PubMed

    Zhang, Yanlin; Wong, J W C; Liu, Peihong; Yuan, Min

    2011-07-15

    Photocatalytic degradation of phenanthrene (PHE) over TiO(2) in aqueous solution containing nonionic surfactant micelles was investigated. All photocatalytic experiments were conducted using a 253.7 nm mercury monochromatic ultraviolet lamp in a photocatalytic reactor. The surfactant micelles could provide a nonaqueous "cage" to result in a higher degradation rate of PHE than in an aqueous solution, but the higher Triton X-100 concentration (more than 2 g/L) lowered the degradation ratio of PHE because the additional surfactant micelles hindered the movement of micelles containing PHE so as to reduce their adsorption onto titania. Pseudo-second-order kinetics was observed for the photocatalytic degradation of PHE. Alkaline solution environment was beneficial to the photocatalytic degradation of PHE. PHE degradation could mainly be attributed to the formation of hydroxyl radicals as evident from the comparison of degradation efficiencies when O(2), H(2)O(2) and tert-butyl alcohol (TBA) were applied as oxidants or hydroxyl radical scavenger. Based on the GC/MS analysis of the intermediates, the possible pathways of the photocatalytic degradation of PHE were proposed.

  13. In vitro percutaneous penetration and characterization of silver from silver-containing textiles

    PubMed Central

    Bianco, Carlotta; Kezic, Sanja; Crosera, Matteo; Svetličić, Vesna; Šegota, Suzana; Maina, Giovanni; Romano, Canzio; Larese, Francesca; Adami, Gianpiero

    2015-01-01

    The objective of this study was to determine the in vitro percutaneous penetration of silver and characterize the silver species released from textiles in different layers of full thickness human skin. For this purpose, two different wound dressings and a garment soaked in artificial sweat were placed in the donor compartments of Franz cells for 24 hours. The concentration of silver in the donor phase and in the skin was determined by an electrothermal atomic absorption spectrometer (ET-AAS) and by inductively coupled plasma mass spectrometer (ICP-MS). The characterization of silver species in the textiles and in the skin layers was made by scanning electron microscopy with integrated energy dispersive X-ray spectroscopy (SEM-EDX). Additionally, the size distribution of silver nanoparticles in the textiles was performed by atomic force microscopy (AFM). On the surface of all investigated materials, silver nanoparticles of different size and morphology were found. Released silver concentrations in the soaking solutions (ie, exposure concentration) ranged from 0.7 to 4.7 μg/mL (0.6–4.0 μg/cm2), fitting the bactericidal range. Silver and silver chloride aggregates at sizes of up to 1 μm were identified both in the epidermis and dermis. The large size of these particles suggests that the aggregation occurred in the skin. The formation of these aggregates likely slowed down the systemic absorption of silver. Conversely, these aggregates may form a reservoir enabling prolonged release of silver ions, which might lead to local effects. PMID:25792824

  14. In vitro percutaneous penetration and characterization of silver from silver-containing textiles.

    PubMed

    Bianco, Carlotta; Kezic, Sanja; Crosera, Matteo; Svetličić, Vesna; Šegota, Suzana; Maina, Giovanni; Romano, Canzio; Larese, Francesca; Adami, Gianpiero

    2015-01-01

    The objective of this study was to determine the in vitro percutaneous penetration of silver and characterize the silver species released from textiles in different layers of full thickness human skin. For this purpose, two different wound dressings and a garment soaked in artificial sweat were placed in the donor compartments of Franz cells for 24 hours. The concentration of silver in the donor phase and in the skin was determined by an electrothermal atomic absorption spectrometer (ET-AAS) and by inductively coupled plasma mass spectrometer (ICP-MS). The characterization of silver species in the textiles and in the skin layers was made by scanning electron microscopy with integrated energy dispersive X-ray spectroscopy (SEM-EDX). Additionally, the size distribution of silver nanoparticles in the textiles was performed by atomic force microscopy (AFM). On the surface of all investigated materials, silver nanoparticles of different size and morphology were found. Released silver concentrations in the soaking solutions (ie, exposure concentration) ranged from 0.7 to 4.7 μg/mL (0.6-4.0 μg/cm(2)), fitting the bactericidal range. Silver and silver chloride aggregates at sizes of up to 1 μm were identified both in the epidermis and dermis. The large size of these particles suggests that the aggregation occurred in the skin. The formation of these aggregates likely slowed down the systemic absorption of silver. Conversely, these aggregates may form a reservoir enabling prolonged release of silver ions, which might lead to local effects.

  15. Trichloroethylene degradation by Escherichia coli containing the cloned Pseudomonas putida F1 toluene dioxygenase genes

    SciTech Connect

    Zylstra, G.J.; Gibson, D.T. ); Wackett, L.P. )

    1989-12-01

    Toluene dioxygenase from Pseudomonas putida F1 has been implicated as an enzyme capable of degrading trichloroethylene. This has now been confirmed with Escherichia coli JM109(pDTG601) that contains the structural genes (todC1C2BA) of toluene dioxygenase under the control of the tac promoter. The extent of trichloroethylene degradation by the recombinant organism depended on the cell concentration and the concentration of trichloroethylene. A linear rate of trichloroethylene degradation was observed with the E. coli recombinant strain. In contrast, P. putida F39/D, a mutant strain of P. putida F1 that does not contain cis-toluene dihydrodiol dehydrogenase, showed a much faster initial rate of trichloroethylene degradation which decreased over time.

  16. Oil-frozen W₁/O/W₂ double emulsions for dermal biomacromolecular delivery containing ethanol as chemical penetration enhancer.

    PubMed

    Jaimes-Lizcano, Yuly A; Lawson, Louise B; Papadopoulos, Kyriakos D

    2011-04-01

    Oil-frozen water-in-oil-in-water (W₁/O/W₂) double emulsions (DE) containing ethanol up to 40% (w/v) in the external aqueous W₂ phase exhibited external coalescence upon thawing of the oil phase, releasing up to 85% of the encapsulated protein of the internal aqueous phase. These emulsions were studied in vitro as potential dermal macromolecular delivery formulations, achieving fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) penetration of up to 86 μm into porcine skin, reaching the viable epidermis where the immunocompetent Langerhans cells are located. Enzyme-linked immunosorbent assay was performed to observe the effect of the emulsification process and ethanol content on the ability of BSA to form antigen-antibody complexes; results indicated that ethanol content and the emulsification process did not diminish the BSA-antibody complex formation when compared with a BSA standard aqueous solution. Therefore, it is shown that oil-frozen W₁/O/W₂ DE, with penetration-enhancing ethanol in the W₂ phase, can potentially be used for cutaneous vaccine delivery formulations. Copyright © 2010 Wiley-Liss, Inc.

  17. Enzymatic degradation of anthracene, dibenzothiophene and pyrene by manganese peroxidase in media containing acetone.

    PubMed

    Eibes, Gemma; Cajthaml, Tomas; Moreira, Maria Teresa; Feijoo, Gumersindo; Lema, Juan M

    2006-06-01

    The high hydrophobicity of polycyclic aromatic hydrocarbons (PAHs) greatly hamper their degradation in liquid media. The use of an organic solvent can assist the degradative action of ligninolytic enzymes from white rot fungi. The enzymatic action of the enzyme manganese peroxidase (MnP) in media containing a miscible organic solvent, acetone (36% v/v), was evaluated as a feasible system for the in vitro degradation of three PAHs: anthracene, dibenzothiophene and pyrene. These compounds were degraded to a large extent after a short period of time (7, 24 and 24h, respectively), at conditions maximizing the MnP-oxidative system. The initial amount of enzyme present in the reaction medium was determinant for the kinetics of the process. The order of degradability, in terms of degradation rates was as follows: anthracene>dibenzothiophene>pyrene. The intermediate compounds were determined using gas chromatography-mass spectrometry and the degradation mechanisms were proposed. Anthracene was degraded to phthalic acid. A ring cleavage product of the oxidation of dibenzothiophene, 4-methoxybenzoic acid, was also observed.

  18. A Highly Sensitive Assay Using Synthetic Blood Containing Test Microbes for Evaluation of the Penetration Resistance of Protective Clothing Material under Applied Pressure.

    PubMed

    Shimasaki, Noriko; Hara, Masayuki; Kikuno, Ritsuko; Shinohara, Katsuaki

    2016-01-01

    To prevent nosocomial infections caused by even either Ebola virus or methicillin-resistant Staphylococcus aureus (MRSA), healthcare workers must wear the appropriate protective clothing which can inhibit contact transmission of these pathogens. Therefore, it is necessary to evaluate the performance of protective clothing for penetration resistance against infectious agents. In Japan, some standard methods were established to evaluate the penetration resistance of protective clothing fabric materials under applied pressure. However, these methods only roughly classified the penetration resistance of fabrics, and the detection sensitivity of the methods and the penetration amount with respect to the relationship between blood and the pathogen have not been studied in detail. Moreover, no standard method using bacteria for evaluation is known. Here, to evaluate penetration resistance of protective clothing materials under applied pressure, the detection sensitivity and the leak amount were investigated by using synthetic blood containing bacteriophage phi-X174 or S. aureus. And the volume of leaked synthetic blood and the amount of test microbe penetration were simultaneously quantified. Our results showed that the penetration detection sensitivity achieved using a test microbial culture was higher than that achieved using synthetic blood at invisible leak level pressures. This finding suggested that there is a potential risk of pathogen penetration even when visual leak of contaminated blood through the protective clothing was not observed. Moreover, at visible leak level pressures, it was found that the amount of test microbe penetration varied at least ten-fold among protective clothing materials classified into the same class of penetration resistance. Analysis of the penetration amount revealed a significant correlation between the volume of penetrated synthetic blood and the amount of test microbe penetration, indicating that the leaked volume of synthetic

  19. Chemical degradation of cyanides by Fenton's reagent in aqueous and soil-containing systems

    SciTech Connect

    Aronstein, B.N. ); Lawal, R.A. ); Maka, A. )

    1994-11-01

    A study was conducted on the effects of pH of the medium, composition of Fenton's reagent, and the effect of soil's preequilibration with the chemical, on the degradation of [sup 14]C-labeled free and complex cyanide in aqueous and soil-containing systems. The application of Fenton's reagent resulted in degradation of 80% and 67% of potassium cyanide in aqueous systems at pH 7.2 and 10.0, respectively. No appreciable amount of K[sub 4][Fe(CN)[sub 6

  20. Massive glycosaminoglycan-dependent entry of Trp-containing cell-penetrating peptides induced by exogenous sphingomyelinase or cholesterol depletion.

    PubMed

    Bechara, Chérine; Pallerla, Manjula; Burlina, Fabienne; Illien, Françoise; Cribier, Sophie; Sagan, Sandrine

    2015-02-01

    Among non-invasive cell delivery strategies, cell-penetrating peptide (CPP) vectors represent interesting new tools. To get fundamental knowledge about the still debated internalisation mechanisms of these peptides, we modified the membrane content of cells, typically by hydrolysis of sphingomyelin or depletion of cholesterol from the membrane outer leaflet. We quantified and visualised the effect of these viable cell surface treatments on the internalisation efficiency of different CPPs, among which the most studied Tat, R9, penetratin and analogues, that all carry the N-terminal biotin-Gly4 tag cargo. Under these cell membrane treatments, only penetratin and R6W3 underwent a massive glycosaminoglycan (GAG)-dependent entry in cells. Internalisation of the other peptides was only slightly increased, similarly in the absence or the presence of GAGs for R9, and only in the presence of GAGs for Tat and R6L3. Ceramide formation (or cholesterol depletion) is known to lead to the reorganisation of membrane lipid domains into larger platforms, which can serve as a trap and cluster receptors. These results show that GAG clustering, enhanced by formation of ceramide, is efficiently exploited by penetratin and R6W3, which contains Trp residues in their sequence but not Tat, R9 and R6L3. Hence, these data shed new lights on the differences in the internalisation mechanism and pathway of these peptides that are widely used in delivery of cargo molecules.

  1. Structural integrity analysis of the degraded drywell containment at the Oyster Creek Nuclear generating station.

    SciTech Connect

    Petti, Jason P.

    2007-01-01

    This study examines the effects of the degradation experienced in the steel drywell containment at the Oyster Creek Nuclear Generating Station. Specifically, the structural integrity of the containment shell is examined in terms of the stress limits using the ASME Boiler and Pressure Vessel (B&PV) Code, Section III, Division I, Subsection NE, and examined in terms of buckling (stability) using the ASME B&PV Code Case N-284. Degradation of the steel containment shell (drywell) at Oyster Creek was first observed during an outage in the mid-1980s. Subsequent inspections discovered reductions in the shell thickness due to corrosion throughout the containment. Specifically, significant corrosion occurred in the sandbed region of the lower sphere. Since the presence of the wet sand provided an environment which supported corrosion, a series of analyses were conducted by GE Nuclear Energy in the early 1990s. These analyses examined the effects of the degradation on the structural integrity. The current study adopts many of the same assumptions and data used in the previous GE study. However, the additional computational recourses available today enable the construction of a larger and more sophisticated structural model.

  2. Treatment of low level radioactive liquid waste containing appreciable concentration of TBP degraded products.

    PubMed

    Valsala, T P; Sonavane, M S; Kore, S G; Sonar, N L; De, Vaishali; Raghavendra, Y; Chattopadyaya, S; Dani, U; Kulkarni, Y; Changrani, R D

    2011-11-30

    The acidic and alkaline low level radioactive liquid waste (LLW) generated during the concentration of high level radioactive liquid waste (HLW) prior to vitrification and ion exchange treatment of intermediate level radioactive liquid waste (ILW), respectively are decontaminated by chemical co-precipitation before discharge to the environment. LLW stream generated from the ion exchange treatment of ILW contained high concentrations of carbonates, tributyl phosphate (TBP) degraded products and problematic radio nuclides like (106)Ru and (99)Tc. Presence of TBP degraded products was interfering with the co-precipitation process. In view of this a modified chemical treatment scheme was formulated for the treatment of this waste stream. By mixing the acidic LLW and alkaline LLW, the carbonates in the alkaline LLW were destroyed and the TBP degraded products got separated as a layer at the top of the vessel. By making use of the modified co-precipitation process the effluent stream (1-2 μCi/L) became dischargeable to the environment after appropriate dilution. Based on the lab scale studies about 250 m(3) of LLW was treated in the plant. The higher activity of the TBP degraded products separated was due to short lived (90)Y isotope. The cement waste product prepared using the TBP degraded product was having good chemical durability and compressive strength. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    SciTech Connect

    Strum, M.J.; Weiss, H.; Farmer, J.C. ); Bullen, D.B. )

    1988-06-01

    This volume surveys the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825. These materials are candidates for the fabrication of containers for the long-term storage of high-level nuclear waste. The metallurgical characteristics of fusion welds are reviewed here and related to potential degradation modes of the containers. Three specific areas are discussed in depth: (1) decreased resistance to corrosion in the forms of preferential corrosion, sensitization, and susceptibility to stress corrosion cracking, (2) hot cracking in the heat-affected zone and the weld zone, and (3) formation of intermetallic phases. The austenitic alloys are ranked as follows in terms of overall weldability: Alloy 825 (best) > Type 316L stainless steel > Type 304L stainless steel (worst). 108 refs., 31 figs., 7 tabs.

  4. Nonsedimentable Microvesicles from Senescing Bean Cotyledons Contain Gel Phase-Forming Phospholipid Degradation Products 1

    PubMed Central

    Yao, Kening; Paliyath, Gopinadhan; Thompson, John E.

    1991-01-01

    A mixture of liquid-crystalline and gel-phase lipid domains is detectable by wide angle x-ray diffraction in smooth microsomal membranes isolated from senescent 7-day-old cotyledons, whereas corresponding membranes from young 2-day-old cotyledons are exclusively liquid-crystalline. The gel-phase domains in the senescent membranes comprise phospholipid degradation products including diacylglycerols, free fatty acids, long-chain aldehydes, and long-chain hydrocarbons. The same complement of phospholipid degradation products is also present in nonsedimentable microvesicles isolated from senescent 7-day-old cotyledons by filtration of a 250,000g, 12-hour supernatant through a 300,000 dalton cut-off filter. The phospholipid degradation products in the microvesicles form gel-phase lipid domains when reconstituted into phospholipid liposomes. Nonsedimentable microvesicles of a similar size, which are again enriched in the same gel-phase-forming phospholipid degradation products, are also generated in vitro from smooth microsomal membranes isolated from 2-day-old cotyledons when Ca2+ is added to activate membrane-associated lipolytic enzymes. The Ca2+-treated membranes do not contain detectable gel-phase domains, suggesting that the phospholipid degradation products are completely removed by microvesiculation. The observations collectively indicate that these nonsedimentable microvesicles serve as a vehicle for moving phospholipid degradation products out of membrane bilayers into the cytosol. As noted previously (Yao K, Paliyath G, Humphrey RW, Hallett FR, Thompson JE [1991] Proc Natl Acad Sci USA 88: 2269-2273), the term “deteriosome” connotes this putative function and would serve to distinguish these microvesicles from other cytoplasmic microvesicles unrelated to deterioration. ImagesFigure 2Figure 3Figure 4Figure 5Figure 6Figure 7 PMID:16668427

  5. Penetration enhancer-containing vesicles (PEVs) as carriers for cutaneous delivery of minoxidil: in vitro evaluation of drug permeation by infrared spectroscopy.

    PubMed

    Mura, Simona; Manconi, Maria; Fadda, Anna Maria; Sala, Maria Chiara; Perricci, Jacopo; Pini, Elena; Sinico, Chiara

    2013-01-01

    Recently, we carried out a research on new liposomal systems prepared by using in their composition a few penetration enhancers which differ for chemical structure and physicochemical properties. The penetration enhancer-containing vesicles (PEVs) were prepared by using soy lecithin and different amounts of three penetration enhancers, 2-(2-ethoxyethoxy) ethanol (Transcutol(®)), capryl-caproyl macrogol 8-glyceride (Labrasol(®)), and cineole.To study the influence of the PEVs on (trans)dermal delivery of minoxidil, in vitro diffusion experiments were performed through new born pig skin and the results were compared with that obtained applying the vesicular system without enhancer (control) after pretreatment of the skin with the various enhancers. In this study, Fourier transform infrared spectroscopy (FTIR), attenuated total reflectance FTIR (ATR-FTIR) and FTIR imaging were used to evaluate the effective penetration of minoxidil in the skin layers and to discover the influence of the enhancer on the drug topical delivery. These analytical studies allowed us to characterize the drug formulations and to evaluate the vesicle distribution into the skin. Recorded spectra confirmed that the vesicle formulations with penetration enhancers promoted drug deposition into the skin.

  6. Degradation of nitrogen containing organic compounds by combined photocatalysis and ozonation.

    PubMed

    Klare, M; Waldner, G; Bauer, R; Jacobs, H; Broekaert, J A

    1999-04-01

    The combination of TiO2-assisted photocatalysis and ozonation in the degradation of nitrogen-containing substrates such as alkylamines, alkanolamines, heterocyclic and aromatic N-compounds has been investigated. A laboratory set-up was designed and the influence of the structure of the N-compound, the TiO2 and ozone concentration on the formation of breakdown products were examined. The experimental results showed that a considerable increase in the degradation efficiency of the N-compounds is obtained by a combination of photocatalysis and ozonation as compared to either ozonation or photocatalysis only. The mineralization of the model substances was monitored by measurements of the TOC and ion-chromatographic determinations of the formed NO2- and NO3-. The temporal changes of concentrations of breakdown products, such as NH4+, short chain alkyl- and alkanolamines were determined by single column ion chromatography (SCIC) and as well as by electrospray mass spectrometry (EI-MS).

  7. Photocatalytic degradation of bentazone in soil washing wastes containing alkylpolyoxyethylene surfactants.

    PubMed

    Davezza, M; Fabbri, D; Pramauro, E; Prevot, A Bianco

    2012-01-01

    Three alkylpolyoxyethylene surfactants bearing the same hydrophobic chain and a different number of oxyethylene groups were investigated as suitable candidates for the soil washing treatment of contaminated soil samples containing bentazone. Comparable good recoveries of the pesticide were obtained working with these surfactants. The photocatalytic treatment of the collected washing wastes, performed in the presence of suspended TiO(2) particles under irradiation with simulated sunlight, leads to the effective degradation of bentazone residues after a time depending on the nature and concentration of the chosen amphiphile. Brij 35 was found to be the best surfactant candidate, giving the faster abatement of the pesticide in the collected wastes. The overall treatment time depends on the bentazone mineralization kinetics, markedly slow in the presence of surfactants. Useful information about the photocatalytic degradation route was obtained from the HPLC-MS analysis of transient intermediates formed in water. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. FT-IR and FT-Raman study of hydrothermally degraded groundwood containing paper

    NASA Astrophysics Data System (ADS)

    Proniewicz, Leonard M.; Paluszkiewicz, Czesława; Wesełucha-Birczyńska, Aleksandra; Barański, Andrzej; Dutka, Dorota

    2002-09-01

    Accelerated aging test of paper is used to understand mechanisms of acidic hydrolysis and oxidative degradation of cellulose, hemicellulose and lignin. In recent years FT-IR and FT-Raman spectroscopy have been used together with mass spectrometry and nuclear magnetic resonance as well as chemometrics methods to characterize degradation products of paper. In this work we present FT-IR and FT-Raman spectra of hydrothermally treated sample of acid paper (Paper 3—bleached sulfite softwood pulp) in extreme humid conditions (100% humidity and 100 °C). Degradation reaction is monitored mainly based on CO stretching vibrations formed during the process of carbonyl compounds, however, some changes in CC stretching vibrations are also noticed. We showed that in these conditions paper undergoes oxidation process in which at least three new carbonyl species that can be characterized by their CO stretches are formed. Additionally, during this process, one can observe disappearance of the CC stretching that can be associated with changes that involve, for example, coniferyl alcohol. We also show that water molecules play very important role in this process. Thus, we report here, changes caused by hydrothermal treatment of groundwood containing paper mainly associated with the appearance of new carbonyl species, besides others, as well as rearrangement of existing hydrogen bond network.

  9. Post-test analysis of a piping penetration in a 1:6-scale model of a reinforced concrete containment building

    SciTech Connect

    Weatherby, J.R.

    1988-01-01

    An overpressurization experiment was conducted on a scale-model of a reinforced concrete containment building. The test was terminated at an internal pressure of 145 psig due to excessive leakage through tears that developed in the steel liner. Virtually all leakage occurred through a 22-inch tear that propagated along the edge of a thickened insert plate that surrounded a piping penetration. This paper describes the results of a post-test finite element analysis of this region. Results of the analysis, visual observations, and thickness measurements all indicate that the 22-inch tear initiated due to high strains near a stud anchor. The results of the analysis also suggest that a relatively simple analytical technique can be used to estimate the pressure at which tears will initiate near penetrations in lined containment structures made of reinforced concrete.

  10. Degradation of alkanolamines in gas-treating solutions: Kinetics of Di-2-propanolamine degradation in aqueous solutions containing carbon dioxide

    SciTech Connect

    Kim, C.J.

    1988-01-01

    The rates and products of degradation of di-2-propanolamine (DIPA) were measured at 100-120/sup 0/C in the presence of a controlled amount of CO/sub 2/. DIPA underwent facile degradation, giving 3-(2-hydroxypropyl)-5-methyl-2-oxazolidone (HPMO) as the main product. Hydrolysis of HPMO occurs readily, but its equilibrium concentration increases with increasing amounts of CO/sub 2/ in solution. A kinetic model was derived and compared with the previously established model for diethanolamines (DEA) degradation. The virtual absence of di- or triamino degradation products is the most striking feature of DIPA degradation, which may be contrasted with the facile formation of di- and triamino products from DEA. This difference is discussed in terms of steric inhibition of the reaction, HPMO + DIPA ..-->.. diamino compounds.

  11. Growth and cyanide degradation of Azotobacter vinelandii in cyanide-containing wastewater system.

    PubMed

    Koksunan, Sarawut; Vichitphan, Sukanda; Laopaiboon, Lakkana; Vichitphan, Kanit; Han, Jaehong

    2013-04-01

    Azotobacter vinelandii, a strict aerobic nitrogen-fixing bacterium, has been extensively studied with regard to the ability of N2-fixation due to its high expression of nitrogenase and fast growth. Because nitrogenase can also reduce cyanide to ammonia and methane, cyanide degradation by A. vinelandii has been studied for the application in the bioremediation of cyanide-contaminated wastewater. Cyanide degradation by A. vinelandii in NFS (nitrogen-free sucrose) medium was examined in terms of cell growth and cyanide reduction, and the results were applied for cyanide-contaminated cassava mill wastewater. From the NFS medium study in the 300 ml flask, it was found that A. vinelandii in the early stationary growth phase could reduce cyanide more rapidly than the cells in the exponential growth phase, and 84.4% of cyanide was degraded in 66 h incubation upon addition of 3.0 mM of NaCN. The resting cells of A. vinelandii could also reduce cyanide concentration by 90.4% with 3.0 mM of NaCN in the large-scale (3 L) fermentation with the same incubation time. Finally, the optimized conditions were applied to the cassava mill wastewater bioremediation, and A. vinelandii was able to reduce the cyanide concentration by 69.7% after 66 h in the cassava mill wastewater containing 4.0 mM of NaCN in the 3 L fermenter. Related to cyanide degradation in the cassava mill wastewater, nitrogenase was the responsible enzyme, which was confirmed by methane production. These findings would be helpful to design a practical bioremediation system for the treatment of cyanide-contaminated wastewater.

  12. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    SciTech Connect

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. ); Gdowski, G.E. )

    1988-06-01

    Three copper-based alloys, CDA 102 (oxygen-free, high-purity copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni), are candidates for the fabrication of high-level radioactive-waste disposal containers. Waste will include spent fuel assemblies from reactors as well as borosilicate glass, and will be sent to the prospective repository site at Yucca Mountain in Nye County, Nevada. The decay of radionuclides will result in the generation of substantial heat and in fluxes of gamma radiation outside the containers. In this environment, container materials might degrade by atmospheric oxidation, general aqueous phase corrosion, localized corrosion (LC), and stress corrosion cracking (SCC). This volume is a critical survey of available data on pitting and crevice corrosion of the copper-based candidates. Pitting and crevice corrosion are two of the most common forms of LC of these materials. Data on the SCC of these alloys is surveyed in Volume 4. Pitting usually occurs in water that contains low concentrations of bicarbonate and chloride anions, such as water from Well J-13 at the Nevada Test Site. Consequently, this mode of degradation might occur in the repository environment. Though few quantitative data on LC were found, a tentative ranking based on pitting corrosion, local dealloying, crevice corrosion, and biofouling is presented. CDA 102 performs well in the categories of pitting corrosion, local dealloying, and biofouling, but susceptibility to crevice corrosion diminishes its attractiveness as a candidate. The cupronickel alloy, CDA 715, probably has the best overall resistance to such localized forms of attack. 123 refs., 11 figs., 3 tabs.

  13. Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene.

    PubMed

    van der Werf, M J; Swarts, H J; de Bont, J A

    1999-05-01

    Strain DCL14, which is able to grow on limonene as a sole source of carbon and energy, was isolated from a freshwater sediment sample. This organism was identified as a strain of Rhodococcus erythropolis by chemotaxonomic and genetic studies. R. erythropolis DCL14 also assimilated the terpenes limonene-1,2-epoxide, limonene-1,2-diol, carveol, carvone, and (-)-menthol, while perillyl alcohol was not utilized as a carbon and energy source. Induction tests with cells grown on limonene revealed that the oxygen consumption rates with limonene-1,2-epoxide, limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and carveol were high. Limonene-induced cells of R. erythropolis DCL14 contained the following four novel enzymatic activities involved in the limonene degradation pathway of this microorganism: a flavin adenine dinucleotide- and NADH-dependent limonene 1, 2-monooxygenase activity, a cofactor-independent limonene-1, 2-epoxide hydrolase activity, a dichlorophenolindophenol-dependent limonene-1,2-diol dehydrogenase activity, and an NADPH-dependent 1-hydroxy-2-oxolimonene 1,2-monooxygenase activity. Product accumulation studies showed that (1S,2S,4R)-limonene-1,2-diol, (1S, 4R)-1-hydroxy-2-oxolimonene, and (3R)-3-isopropenyl-6-oxoheptanoate were intermediates in the (4R)-limonene degradation pathway. The opposite enantiomers [(1R,2R,4S)-limonene-1,2-diol, (1R, 4S)-1-hydroxy-2-oxolimonene, and (3S)-3-isopropenyl-6-oxoheptanoate] were found in the (4S)-limonene degradation pathway, while accumulation of (1R,2S,4S)-limonene-1,2-diol from (4S)-limonene was also observed. These results show that R. erythropolis DCL14 metabolizes both enantiomers of limonene via a novel degradation pathway that starts with epoxidation at the 1,2 double bond forming limonene-1,2-epoxide. This epoxide is subsequently converted to limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and 7-hydroxy-4-isopropenyl-7-methyl-2-oxo-oxepanone. This lactone spontaneously rearranges to form 3-isopropenyl-6-oxoheptanoate

  14. Rhodococcus erythropolis DCL14 Contains a Novel Degradation Pathway for Limonene

    PubMed Central

    van der Werf, Mariët J.; Swarts, Henk J.; de Bont, Jan A. M.

    1999-01-01

    Strain DCL14, which is able to grow on limonene as a sole source of carbon and energy, was isolated from a freshwater sediment sample. This organism was identified as a strain of Rhodococcus erythropolis by chemotaxonomic and genetic studies. R. erythropolis DCL14 also assimilated the terpenes limonene-1,2-epoxide, limonene-1,2-diol, carveol, carvone, and (−)-menthol, while perillyl alcohol was not utilized as a carbon and energy source. Induction tests with cells grown on limonene revealed that the oxygen consumption rates with limonene-1,2-epoxide, limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and carveol were high. Limonene-induced cells of R. erythropolis DCL14 contained the following four novel enzymatic activities involved in the limonene degradation pathway of this microorganism: a flavin adenine dinucleotide- and NADH-dependent limonene 1,2-monooxygenase activity, a cofactor-independent limonene-1,2-epoxide hydrolase activity, a dichlorophenolindophenol-dependent limonene-1,2-diol dehydrogenase activity, and an NADPH-dependent 1-hydroxy-2-oxolimonene 1,2-monooxygenase activity. Product accumulation studies showed that (1S,2S,4R)-limonene-1,2-diol, (1S,4R)-1-hydroxy-2-oxolimonene, and (3R)-3-isopropenyl-6-oxoheptanoate were intermediates in the (4R)-limonene degradation pathway. The opposite enantiomers [(1R,2R,4S)-limonene-1,2-diol, (1R,4S)-1-hydroxy-2-oxolimonene, and (3S)-3-isopropenyl-6-oxoheptanoate] were found in the (4S)-limonene degradation pathway, while accumulation of (1R,2S,4S)-limonene-1,2-diol from (4S)-limonene was also observed. These results show that R. erythropolis DCL14 metabolizes both enantiomers of limonene via a novel degradation pathway that starts with epoxidation at the 1,2 double bond forming limonene-1,2-epoxide. This epoxide is subsequently converted to limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and 7-hydroxy-4-isopropenyl-7-methyl-2-oxo-oxepanone. This lactone spontaneously rearranges to form 3-isopropenyl-6-oxoheptanoate. In

  15. Photocatalytic degradation of organochlorine compounds over titanium oxide and titanium oxide containing zinc oxide decatungstate and hydrogen peroxide

    SciTech Connect

    Sattari, D.

    1995-12-01

    Ten organochlorine solvents, commonly used in industry, which are di- tri- and tetra- chloro derivatives of methane, ethane and ethylene were photocatalytically degraded over titanium oxide and titanium oxide containing zinc oxide: decatungstate and hydrogen peroxide. The study has been carried out by determining the yield of organochlorine degradation at different irradiation time. It was found that for derivatives of the three compounds the degradation rates were in the order of di>tri>tetra and for those containing the same number of chlorine substituents the order was ethylene>ethane. During the degradation of each organochlorine solvent chloride was liberated. Stoichiometry for photocatalytic degradation of organochlorine solvents are C{sub x}H{sub y-z}Cl{sub z} + xO{sub 2}{yields}xCO{sub 2} + (y-z)H{sup +} + zCl{sup -}.

  16. α-Amino acid containing degradable polymers as functional biomaterials: rational design, synthetic pathway, and biomedical applications.

    PubMed

    Sun, Huanli; Meng, Fenghua; Dias, Aylvin A; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

    2011-06-13

    Currently, biomedical engineering is rapidly expanding, especially in the areas of drug delivery, gene transfer, tissue engineering, and regenerative medicine. A prerequisite for further development is the design and synthesis of novel multifunctional biomaterials that are biocompatible and biologically active, are biodegradable with a controlled degradation rate, and have tunable mechanical properties. In the past decades, different types of α-amino acid-containing degradable polymers have been actively developed with the aim to obtain biomimicking functional biomaterials. The use of α-amino acids as building units for degradable polymers may offer several advantages: (i) imparting chemical functionality, such as hydroxyl, amine, carboxyl, and thiol groups, which not only results in improved hydrophilicity and possible interactions with proteins and genes, but also facilitates further modification with bioactive molecules (e.g., drugs or biological cues); (ii) possibly improving materials biological properties, including cell-materials interactions (e.g., cell adhesion, migration) and degradability; (iii) enhancing thermal and mechanical properties; and (iv) providing metabolizable building units/blocks. In this paper, recent developments in the field of α-amino acid-containing degradable polymers are reviewed. First, synthetic approaches to prepare α-amino acid-containing degradable polymers will be discussed. Subsequently, the biomedical applications of these polymers in areas such as drug delivery, gene delivery and tissue engineering will be reviewed. Finally, the future perspectives of α-amino acid-containing degradable polymers will be evaluated.

  17. Structure, surface reactivity and physico-chemical degradation of fluoride containing phospho-silicate glasses

    SciTech Connect

    Kansal, Ishu; Goel, Ashutosh; Tulyaganov, Dilshat U.; Santos, Luis F.; Ferreira, Jose M.

    2011-03-28

    We report on the structure, apatite-forming ability and physicochemical degradation of glasses along fluorapatite [FA; Ca5(PO4)3F] - diopside (Di; CaMgSi2O6) join. A series of glasses with varying FA/Di ratio have been synthesised by melt-quenching technique. The amorphous glasses could be obtained only for compositions up to 40 wt.% of FA. The detailed structural analysis of glasses has been made by infra-red spectroscopy (FTIR), Raman spectroscopy and magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR). Silicon was predominantly present as Q2 (Si) species while phosphorus was found in orthophosphate type environment in all the investigated glasses. The apatite forming ability of glasses was investigated by immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1 h – 28 days. An extensive precipitation of calcite (CaCO3) after immersion in SBF was found in all the glasses which considerably masked the formation of hydroxyapatite [HA; Ca5(PO4)3OH] as depicted by X-ray diffraction (XRD) and FTIR. The possible mechanism favouring formation of calcite instead of HA has been explained on the basis of experimental results obtained for structure of glasses, leaching profile of glass powders in SBF solution and pH variation in SBF solution. Further, physico-chemical degradation of glasses has been studied in accordance with ISO 10993-14 “Biological evaluation of medical devices – Part 14: Identification and quantification of degradation products from ceramics” in Tris HCl and citric acid buffer. All the FA containing glasses exhibited a weight gain (instead of weight loss) after immersion in citric acid buffer due to the formation of different crystalline products.

  18. Degradation of solid oxide fuel cell metallic interconnects in fuels containing sulfur

    SciTech Connect

    Ziomek-Moroz, M.; Hawk, Jeffrey A.

    2005-01-01

    Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from all manner of fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Impurities in the fuel can cause significant performance problems and sulfur, in particular, can decrease the cell performance of fuel cells, including solid oxide fuel cells (SOFC). In the SOFC, the high (800-1000°C) operating temperature yields advantages (e.g., internal fuel reforming) and disadvantages (e.g., material selection and degradation problems). Significant progress in reducing the operating temperature of the SOFC from ~1000 ºC to ~750 ºC may allow less expensive metallic materials to be used for interconnects and as balance of plant (BOP) materials. This paper provides insight on the material performance of nickel, ferritic steels, and nickel-based alloys in fuels containing sulfur, primarily in the form of H2S, and seeks to quantify the extent of possible degradation due to sulfur in the gas stream.

  19. Degradation mechanisms of sulfur and nitrogen containing compounds during thermal stability testing of model fuels

    NASA Technical Reports Server (NTRS)

    Reddy, K. T.; Cernansky, N. P.; Cohen, R. S.

    1987-01-01

    The degradation behavior of n-dodecane (singly or in combination with S- and N-containing dopants) was studied using a modified Jet Fuel Thermal Oxidation Tester facility between 200 and 400 C. The products were analyzed by gas chromatography and mass spectrometry. The soluble products consisted mainly of n-alkanes and 1-alkenes, aldehydes, tetrahydrofuran derivatives, dodecanol and dodecanone isomers, C21-C24 alkane isomers, and dodecylhydroperoxide (ROOH) decomposition products. The major products were always the same, with and without dopants, but their distributions varied considerably. The 3,4-dimercaptotoluene and dibutylsulfide dopants added individually to n-dodecane interferred with the hydrocarbon oxidation at the alkylperoxy radical and the alkylhydroperoxide link, respectively, while the 2,5-dimethylpyrrole dopant inhibited ROOH formation. Pyridine, pyrrole, and dibenzothiophene added individually showed few significant effects.

  20. Degradation mechanisms of sulfur and nitrogen containing compounds during thermal stability testing of model fuels

    NASA Technical Reports Server (NTRS)

    Reddy, K. T.; Cernansky, N. P.; Cohen, R. S.

    1987-01-01

    The degradation behavior of n-dodecane (singly or in combination with S- and N-containing dopants) was studied using a modified Jet Fuel Thermal Oxidation Tester facility between 200 and 400 C. The products were analyzed by gas chromatography and mass spectrometry. The soluble products consisted mainly of n-alkanes and 1-alkenes, aldehydes, tetrahydrofuran derivatives, dodecanol and dodecanone isomers, C21-C24 alkane isomers, and dodecylhydroperoxide (ROOH) decomposition products. The major products were always the same, with and without dopants, but their distributions varied considerably. The 3,4-dimercaptotoluene and dibutylsulfide dopants added individually to n-dodecane interferred with the hydrocarbon oxidation at the alkylperoxy radical and the alkylhydroperoxide link, respectively, while the 2,5-dimethylpyrrole dopant inhibited ROOH formation. Pyridine, pyrrole, and dibenzothiophene added individually showed few significant effects.

  1. Atmospheric degradation mechanisms of hydrogen containing chlorofluorocarbons (HCFC) and fluorocarbons (HFC)

    NASA Technical Reports Server (NTRS)

    Zellner, Reinhard

    1990-01-01

    The current knowledge of atmospheric degradation of hydrogen containing chlorofluorocarbons (HCFC 22 (CHClF2), HCFC 123 (CHCl2CF3), HCFC 124 (CHClFCF3), HCFC 141b (CFCl2CH3), HCFC 142b (CF2ClCH3)) and fluorocarbons (HFC 125 (CHF2CF3), HFC 134a (CH2FCF3), HFC 152a (CHF2CH3)) is assessed. Except for the initiation reaction by OH radicals, there are virtually no experimental data available concerning the subsequent oxidative breakdown of these molecules. However, from an analogy to the degradation mechanisms of simple alkanes, some useful guidelines as to the expected intermediates and final products can be derived. A noteable exception from this analogy, however, appears for the oxi-radicals. Here, halogen substitution induces new reaction types (C-Cl and C-C bond ruptures) which are unknown to the unsubstituted analogues and which modify the nature of the expected carbonyl products. Based on an evaluation of these processes using estimated bond strength data, the following simplified rules with regards to the chlorine content of the HCFC's may be deduced: (1) HCFC's containing one chlorine atom such as 22 and 142b seem to release their chlorine content essentially instantaneous with the initial attack on the parent by OH radicals, and for HCFC 124, such release is apparently prevented; (2) HCFC's such as 123 and 141b with two chlorine atoms are expected to release only one of these instantaneously; and the second chlorine atom may be stored in potentially long-lived carbonyl compounds such as CF3CClO or CClFO.

  2. Topical formulations containing finasteride. Part II: determination of finasteride penetration into hair follicles using the differential stripping technique.

    PubMed

    Tampucci, Silvia; Burgalassi, Susi; Chetoni, Patrizia; Lenzi, Carla; Pirone, Andrea; Mailland, Federico; Caserini, Maurizio; Monti, Daniela

    2014-08-01

    The differential stripping technique consists of a tape-stripping phase followed by a cyanoacrylate biopsy. This technique not only allows the quantification of drug retained in the stratum corneum (SC) and in the hair follicles but also differentiates transepidermal from transfollicular penetration. Our study aimed at both validating the differential stripping procedure on hairless rat skin and assessing the role of the hair follicle in the cutaneous penetration of finasteride (FNS) after application of two experimental formulations for 6 or 24 h: P-08-016, a hydroxypropyl chitosan (HPCH)-based formulation and P-10-008, an anhydrous formulation devoid of HPCH. Microscopic and histological evaluation showed that after 15 tape strips both the SC and the viable epidermis were completely removed. A subsequent cyanoacrylate skin surface biopsy led to the removal of the infundibula content. The largest amounts of FNS were found in the epidermis and in the appendages after application of P-08-016, regardless of the time from application. In contrast, smaller and statistically significant amounts of FNS were recovered with P-10-008 6 h after application, compared with that at 24 h. In conclusion, the differential stripping technique allowed determination of the amount of FNS localized in different skin districts, focusing particularly on the follicular contribution.

  3. Formulation and in vitro evaluation of clotrimazole gel containing almond oil and tween 80 as penetration enhancer for topical application.

    PubMed

    Nawaz, Asif; Jan, Syed Umer; Khan, Nauman Rahim; Hussain, Abid; Khan, Gul Majid

    2013-05-01

    Achieving a desirable percutaneous absorption of drug molecule is a major concern in formulating dermal and transdermal products. The use of penetration enhancers could provide a successful mean for this purpose. The aim of this study was to develop Clotrimazole gel and to evaluate the effect of almond oil and tween 80 (in different concentrations), on the permeation of drug through rabbit skin in vitro. In order to investigate the effect of penetration enhancers used in this study on the permeation of Clotrimazole through sections of excised rabbit skin, Franz diffusion cell was employed. Sample solution was withdrawn at specific time interval up to 24 h. Significant difference in permeation among the eight formulations was seen in the study. The permeation profile of various formulations also showed that the added enhancers in individual batches affected the permeation of the drug. Drug permeation increased with increased concentration of Tween 80 and decreased concentration of almond oil. Furthermore, almond oil combined with tween 80 showed synergistic effect. The clotrimazole gels were successfully formulated and could be beneficial for topical use.

  4. An efficient PEGylated liposomal nanocarrier containing cell-penetrating peptide and pH-sensitive hydrazone bond for enhancing tumor-targeted drug delivery

    PubMed Central

    Ding, Yuan; Sun, Dan; Wang, Gui-Ling; Yang, Hong-Ge; Xu, Hai-Feng; Chen, Jian-Hua; Xie, Ying; Wang, Zhi-Qiang

    2015-01-01

    Cell-penetrating peptides (CPPs) as small molecular transporters with abilities of cell penetrating, internalization, and endosomal escape have potential prospect in drug delivery systems. However, a bottleneck hampering their application is the poor specificity for cells. By utilizing the function of hydration shell of polyethylene glycol (PEG) and acid sensitivity of hydrazone bond, we constructed a kind of CPP-modified pH-sensitive PEGylated liposomes (CPPL) to improve the selectivity of these peptides for tumor targeting. In CPPL, CPP was directly attached to liposome surfaces via coupling with stearate (STR) to avoid the hindrance of PEG as a linker on the penetrating efficiency of CPP. A PEG derivative by conjugating PEG with STR via acid-degradable hydrazone bond (PEG2000-Hz-STR, PHS) was synthesized. High-performance liquid chromatography and flow cytometry demonstrated that PHS was stable at normal neutral conditions and PEG could be completely cleaved from liposome surface to expose CPP under acidic environments in tumor. An optimal CPP density on liposomes was screened to guaranty a maximum targeting efficiency on tumor cells as well as not being captured by normal cells that consequently lead to a long circulation in blood. In vitro and in vivo studies indicated, in 4 mol% CPP of lipid modified system, that CPP exerted higher efficiency on internalizing the liposomes into targeted subcellular compartments while remaining inactive and free from opsonins at a maximum extent in systemic circulation. The 4% CPPL as a drug delivery system will have great potential in the clinical application of anticancer drugs in future. PMID:26491292

  5. CO2-induced degradation of amine-containing adsorbents: reaction products and pathways.

    PubMed

    Sayari, Abdelhamid; Heydari-Gorji, Aliakbar; Yang, Yong

    2012-08-22

    A comprehensive study was conducted to investigate the stability of a wide variety of mesoporous silica-supported amine-containing adsorbents in the presence of carbon dioxide under dry conditions. CO(2)-induced degradation of grafted primary and secondary monoamines (pMono, sMono), diamines with one primary and one secondary amines (Diamine) and triamine with one primary and two secondary amines (TRI) as well as different impregnated polyamines such as branched and linear polyethylenimine (BPEI and LPEI) and polyallylamine (PALL) was investigated using extensive CO(2) adsorption-desorption cycling as well as diffuse reflectance infrared Fourier transform (DRIFT) and (13)C CP MAS NMR measurements. Except for sMono, all other supported amines underwent significant deactivation in the presence of dry CO(2) under mild conditions. In all cases, the decrease in CO(2) uptake was associated with the formation of urea linkages at the expense of amine groups. The urea-containing species were identified, and the deactivation pathways were delineated.

  6. The abiotic degradation of methyl parathion in anoxic sulfur-containing system mediated by natural organic matter.

    PubMed

    Liao, Xiaoping; Zhang, Caixiang; Wang, Yanxin; Tang, Mi

    2017-06-01

    Although the kinetics and transformation of methyl parathion have been investigated extensively, its abiotic degradation mechanism in anoxic sulfur-containing groundwater system is still not clear. In this work, the abiotic degradation of methyl parathion in anoxic sulfur-containing system mediated by natural organic matter (NOM) was investigated in batch experiments. It was found that the removal of methyl parathion (up to 80.7%) was greatly improved in sulfide containing NOM compared to those in sulfide alone (with 15.5%) and in NOM alone (almost negligible). Various sulfur species presented significant differences in behaviors methyl parathion degradation, but followed by the pseudo-first-order model well. No facilitated degradation of methyl parathion was observed in sulfite (SO3(2-)) or thiosulfate (S2O3(2-)) containing NOM such as anthraquinone. Although elemental sulfur (S(0)) and cysteine could further improve the degradation rate of methyl parahtion, their impacts was very limited. The removal efficiency of methyl parathion in anoxic sulfur-containing system were related remarkably with NOM concentration and solution pH. Based on the transformation products identified by gas chromatography-mass spectrometer (GC/MS) and liquid chromatography high resolution mass spectrometer (LC/HRMS), both the nitro group reduction and hydrolysis (SN@C) processes by sulfide (HS(-)) were further proved to be two predominant reaction mechanisms for the abiotic degradation of methyl parathion in anoxic sulfur-containing system. The results of this study help to understand the natural attenuation of methyl parathion under anoxic sulfide-containing groundwater system mediated by NOM.

  7. The effect of pelleting on in situ rumen degradability of compound feed containing brown rice for dairy cows.

    PubMed

    Tagawa, Shin-Ichi; Yoshida, Norio; Iino, Yukihiro; Horiguchi, Ken-Ichi; Takahashi, Toshiyoshi; Watanabe, Maria; Takemura, Kei; Ito, Syuhei; Mikami, Toyoji

    2017-01-01

    This study was conducted to determine the effect of pelleting on in situ dry matter degradability of pelleted compound feed containing brown rice for dairy cows. Mash feed of the same composition was used as a control and the in situ study was conducted using three non-lactating Holstein steers fitted with a rumen cannula. The feeds contained 32.3% brown rice, 19.4% rapeseed meal, 11.4% wheat bran and 10.6% soybean meal (fresh weight basis). Except for moisture content, the chemical composition of the feed was not affected by pelleting. In situ dry matter disappearance of the feed increased from 0 to 2 h and after 72 h of incubation with pellet processing. Integration of the dry matter disappearance values over time revealed that degradability parameter a (soluble fraction) increased with pellet processing, whereas parameter b (potentially degradable fraction) decreased. Parameter c (fractional rate of degradation) and effective degradability (5% passage rate) were not affected by pellet processing. We concluded that pellet processing promotes rumen degradability at early incubation hours when the pelleted feed contains brown rice. © 2016 Japanese Society of Animal Science.

  8. Effectiveness of a model constructed wetland system containing Cyperus papyrus in degrading diesel oil

    NASA Astrophysics Data System (ADS)

    Harbowo, Danni Gathot; Choesin, Devi Nandita

    2014-03-01

    Synergism between wetland systems and the provision of degrading bacterial inoculum is now being developed for the recovery of areas polluted waters of pollutants. In connection with the frequent cases of diesel oil pollution in the waters of Indonesia, we need a way of water treatment as an efficient. In this study conducted a series of tests to develop an construcred wetland design that can effectively degrade diesel oil. Tested five systems: blanko (A), substrated, without bacterial inoculums, and vegetation (B); with the addition of inoculum (C); subsrated and vegetated (D); substrated and vegetated with the addition of inoculum (E). Vegetation used in this study is Cyperus papyrus because it has the ability to absorb pollutants. Inoculum used was Pseudomonas aeruginosa and Enterobacter aerogenes which is a bacteria degrading organic compounds commonly found in water. To measure the effectiveness of the system, use several indicators to see the degradation of pollutants, namely changes in viscosity, surface tension of pollutants, and the emergence of compound degradation. Based on the results of the study can be determined that the substrated and vegetated system with Cyperus papyrus inoculum (E) was considered the most capable of degrading diesel oil due to the large changes in all parameters. In the system E, 40.6% increase viscosity, surface tension decreased 32.7%, the appearance of degradation compounds with relatively 3614.7 points, and increased to 227.8% TDS. In addition the environmental conditions in the system E also supports the growth of vegetation and degrading microbes.

  9. Characterization of Brain-Penetrant Pyrimidine-Containing Molecules with Differential Microtubule-Stabilizing Activities Developed as Potential Therapeutic Agents for Alzheimer’s Disease and Related Tauopathies

    PubMed Central

    Kovalevich, Jane; Cornec, Anne-Sophie; Yao, Yuemang; James, Michael; Crowe, Alexander; Lee, Virginia M.-Y.; Trojanowski, John Q.; Smith, Amos B.

    2016-01-01

    The microtubule (MT)–stabilizing protein tau disengages from MTs and forms intracellular inclusions known as neurofibrillary tangles in Alzheimer’s disease and related tauopathies. Reduced tau binding to MTs in tauopathies may contribute to neuronal dysfunction through decreased MT stabilization and disrupted axonal transport. Thus, the introduction of brain-penetrant MT-stabilizing compounds might normalize MT dynamics and axonal deficits in these disorders. We previously described a number of phenylpyrimidines and triazolopyrimidines (TPDs) that induce tubulin post-translational modifications indicative of MT stabilization. We now further characterize the biologic properties of these small molecules, and our results reveal that these compounds can be divided into two general classes based on the cellular response they evoke. One group composed of the phenylpyrimidines and several TPD examples showed a bell-shaped concentration-response effect on markers of MT stabilization in cellular assays. Moreover, these compounds induced proteasome-dependent degradation of α- and β-tubulin and caused altered MT morphology in both dividing cells and neuron cultures. In contrast, a second group comprising a subset of TPD molecules (TPD+) increased markers of stable MTs in a concentration-dependent manner in dividing cells and in neurons without affecting total tubulin levels or disrupting MT architecture. Moreover, an example TPD+ compound was shown to increase MTs in a neuron culture model with induced tau hyperphosphorylation and associated MT deficits. Several TPD+ compounds were shown to be both brain penetrant and orally bioavailable, and a TPD+ example increased MT stabilization in the mouse brain, making these compounds potential candidate therapeutics for neurodegenerative tauopathies such as Alzheimer’s disease. PMID:26980057

  10. Liquid penetrants

    NASA Technical Reports Server (NTRS)

    Pasley, R. L.

    1973-01-01

    Liquid-penetrant inspection is discussed for surface defects in solids. The principle advantages are considered to be its simplicity and economy. The techniques and penetrants are described along with the developers. Commercially available equipment is also described.

  11. Thermally induced degradation of sulfur-containing aliphatic glucosinolates in broccoli sprouts (Brassica oleracea var. italica) and model systems.

    PubMed

    Hanschen, Franziska S; Platz, Stefanie; Mewis, Inga; Schreiner, Monika; Rohn, Sascha; Kroh, Lothar W

    2012-03-07

    Processing reduces the glucosinolate (GSL) content of plant food, among other aspects due to thermally induced degradation. Since there is little information about the thermal stability of GSL and formation of corresponding breakdown products, the thermally induced degradation of sulfur-containing aliphatic GSL was studied in broccoli sprouts and with isolated GSL in dry medium at different temperatures as well as in aqueous medium at different pH values. Desulfo-GSL have been analyzed with HPLC-DAD, while breakdown products were estimated using GC-FID. Whereas in the broccoli sprouts structural differences of the GSL with regard to thermal stability exist, the various isolated sulfur-containing aliphatic GSL degraded nearly equally and were in general more stable. In broccoli sprouts, methylsulfanylalkyl GSL were more susceptible to degradation at high temperatures, whereas methylsulfinylalkyl GSL were revealed to be more affected in aqueous medium under alkaline conditions. Besides small amounts of isothiocyanates, the main thermally induced breakdown products of sulfur-containing aliphatic GSL were nitriles. Although they were most rapidly formed at comparatively high temperatures under dry heat conditions, their highest concentrations were found after cooking in acidic medium, conditions being typical for domestic processing.

  12. Photocatalytic degradation of chlorophenols in soil washing wastes containing Brij 35. Correlation between the degradation kinetics and the pollutants-micelle binding.

    PubMed

    Davezza, M; Fabbri, D; Pramauro, E; Prevot, A Bianco

    2013-05-01

    The photocatalytic degradations of 4-chlorophenol (CP), 4-chloro-2-methylphenol (CMP), 4-chloro-3,5-dimethylphenol (CDMP) and 4-chloro-2-isopropyl-5-methylphenol (CIMP) were investigated in water and in simulated soil washing wastes containing Brij 35 (polyoxyethylene(23)dodecyl ether) in the presence of TiO2 dispersions. A neat inhibition of substrate decomposition proportional to their growing hydrophobicity was observed in the washing wastes for CP, CMP and CDMP, whereas CIMP showed a different behaviour. The mineralization of the organic chlorine of CP and CIMP was relatively fast and complete, whereas it was much slower for CMP and CDMP. Micellar solubilization and substrate adsorption onto the semiconductor play opposite roles on the degradation kinetics, and a breakpoint between the corresponding induced effects was evidenced when the pollutants become completely bound to the micellar aggregates.

  13. Lack of Significant Dermal Penetration of Titanium Dioxide from Sunscreen Formulations Containing Nano- and Submicron-Size TiO2 Particles

    PubMed Central

    Sadrieh, Nakissa; Wokovich, Anna M.; Gopee, Neera V.; Zheng, Jiwen; Haines, Diana; Parmiter, David; Siitonen, Paul H.; Cozart, Christy R.; Patri, Anil K.; McNeil, Scott E.; Howard, Paul C.; Doub, William H.; Buhse, Lucinda F.

    2010-01-01

    Titanium dioxide (TiO2) is included in some sunscreen formulations to physically block ultraviolet radiation. A dermal penetration study was conducted in minipigs with three TiO2 particles (uncoated submicron sized, uncoated nano-sized, and dimethicone/methicone copolymer-coated nanosized) applied 5% by weight in a sunscreen. These and control formulations were topically applied to minipigs at 2 mg cream/cm2 skin (4 applications/day, 5 days/week, 4 weeks). Skin (multiple sites), lymph nodes, liver, spleen, and kidneys were removed, and the TiO2 content was determined (as titanium) using inductively coupled plasma mass spectroscopy. Titanium levels in lymph nodes and liver from treated animals were not increased over the values in control animals. The epidermis from minipigs treated with sunscreens containing TiO2 showed elevated titanium. Increased titanium was detected in abdominal and neck dermis of minipigs treated with uncoated and coated nanoscale TiO2. Using electron microscopy-energy dispersive x-ray analysis, all three types of TiO2 particles were found in the stratum corneum and upper follicular lumens in all treated skin samples (more particles visible with coated nanoscale TiO2). Isolated titanium particles were also present at various locations in the dermis of animals treated with all three types of TiO2-containing sunscreens; however, there was no pattern of distribution or pathology suggesting the particles could be the result of contamination. At most, the few isolated particles represent a tiny fraction of the total amount of applied TiO2. These findings indicate that there is no significant penetration of TiO2 nanoparticles through the intact normal epidermis. PMID:20156837

  14. Lack of significant dermal penetration of titanium dioxide from sunscreen formulations containing nano- and submicron-size TiO2 particles.

    PubMed

    Sadrieh, Nakissa; Wokovich, Anna M; Gopee, Neera V; Zheng, Jiwen; Haines, Diana; Parmiter, David; Siitonen, Paul H; Cozart, Christy R; Patri, Anil K; McNeil, Scott E; Howard, Paul C; Doub, William H; Buhse, Lucinda F

    2010-05-01

    Titanium dioxide (TiO(2)) is included in some sunscreen formulations to physically block ultraviolet radiation. A dermal penetration study was conducted in minipigs with three TiO(2) particles (uncoated submicron sized, uncoated nano-sized, and dimethicone/methicone copolymer-coated nanosized) applied 5% by weight in a sunscreen. These and control formulations were topically applied to minipigs at 2 mg cream/cm(2) skin (4 applications/day, 5 days/week, 4 weeks). Skin (multiple sites), lymph nodes, liver, spleen, and kidneys were removed, and the TiO(2) content was determined (as titanium) using inductively coupled plasma mass spectroscopy. Titanium levels in lymph nodes and liver from treated animals were not increased over the values in control animals. The epidermis from minipigs treated with sunscreens containing TiO(2) showed elevated titanium. Increased titanium was detected in abdominal and neck dermis of minipigs treated with uncoated and coated nanoscale TiO(2). Using electron microscopy-energy dispersive x-ray analysis, all three types of TiO(2) particles were found in the stratum corneum and upper follicular lumens in all treated skin samples (more particles visible with coated nanoscale TiO(2)). Isolated titanium particles were also present at various locations in the dermis of animals treated with all three types of TiO(2)-containing sunscreens; however, there was no pattern of distribution or pathology suggesting the particles could be the result of contamination. At most, the few isolated particles represent a tiny fraction of the total amount of applied TiO(2). These findings indicate that there is no significant penetration of TiO(2) nanoparticles through the intact normal epidermis.

  15. Dermal penetration of creatine from a face-care formulation containing creatine, guarana and glycerol is linked to effective antiwrinkle and antisagging efficacy in male subjects.

    PubMed

    Peirano, Reto I; Achterberg, Volker; Düsing, Hans-Jürgen; Akhiani, Mehdi; Koop, Urte; Jaspers, Sören; Krüger, Andrea; Schwengler, Helge; Hamann, Tina; Wenck, Horst; Stäb, Franz; Gallinat, Stefan; Blatt, Thomas

    2011-12-01

      The dermal extracellular matrix provides stability and structure to the skin. With increasing age, however, its major component collagen is subject to degeneration, resulting in a gradual decline in skin elasticity and progression of wrinkle formation. Previous studies suggest that the reduction in cellular energy contributes to the diminished synthesis of cutaneous collagen during aging.   To investigate the potential of topically applied creatine to improve the clinical signs of skin aging by stimulating dermal collagen synthesis in vitro and in vivo.   Penetration experiments were performed with a pig skin ex vivo model. Effects of creatine on dermal collagen gene expression and procollagen synthesis were studied in vitro using cultured fibroblast-populated collagen gels. In a single-center, controlled study, 43 male Caucasians applied a face-care formulation containing creatine, guarana extract, and glycerol to determine its influence on facial topometric features.   Cultured human dermal fibroblasts supplemented with creatine displayed a stimulation of collagen synthesis relative to untreated control cells both on the gene expression and at the protein level. In skin penetration experiments, topically applied creatine rapidly reached the dermis. In addition, topical in vivo application of a creatine-containing formulation for 6 weeks significantly reduced the sagging cheek intensity in the jowl area as compared to baseline. This result was confirmed by clinical live scoring, which also demonstrated a significant reduction in crow's feet wrinkles and wrinkles under the eyes.   In summary, creatine represents a beneficial active ingredient for topical use in the prevention and treatment of human skin aging. © 2011 Wiley Periodicals, Inc.

  16. Liposome-containing Hibiscus sabdariffa calyx extract formulations with increased antioxidant activity, improved dermal penetration and reduced dermal toxicity.

    PubMed

    Pinsuwan, Sirirat; Amnuaikit, Thanaporn; Ungphaiboon, Suwipa; Itharat, Arunporn

    2010-12-01

    Hibiscus sabdariffa Linn, or Roselle, is a medicinal plant used extensively in traditional Thai medicine since ancient times. The extracts of Roselle calyces possess antioxidant activity and have potential for development as active ingredients in cosmetic products. However the limitations of using Roselle extracts in cosmetics are its low skin permeation and dermal irritation. Liposome technology is an obvious approach that might overcome these problems. Liposome formulations of standardized Roselle extracts were developed with various lipid components. The formulation showing the highest entrapment efficiency was selected for stability, skin permeation and dermal irritability studies. The liposome formulation with the highest entrapment efficiency (83%) and smalôlest particle size (332 mm) was formulated with phosphatidylcholine from soybean (SPC): Tween 80: deoxycholic acid (DA); 84:16:2.5 weight ratio, total lipid of 200 g/mL and 10% w/v Roselle extract in final liposomal preparation. This liposome formulation was found to be stable after storage at 4 degrees C, protected from light, for 2 months. The in vitro skin permeation studies, using freshly excised pig skin and modified Franz-diffusion cells, showed that the liposome formulation was able to considerably increased the rate of permeation of active compounds in Roselle extracts compared to the Roselle extract solution. The in vivo dermal irritability testing on rabbit skin showed that the liposome formulation dramatically decreased skin irritability compared to the unformulated extract. These results showed that the liposomes containing Roselle extracts had good stability, high entrapment efficacy, increased skin permeation and low skin irritation.

  17. Biostimulation of PAH degradation with plants containing high concentrations of linoleic acid.

    PubMed

    Yi, Haakrho; Crowley, David E

    2007-06-15

    Many plant species enhance the biodegradation of polycyclic aromatic hydrocarbons (PAHs), but there is little understanding of the mechanisms by which this occurs. This research identified phytochemicals that stimulate pyrene degradation using crushed roottissues from 43 plants that were screened in soil spiked with 100 ppm pyrene. Among the plants tested, root tissues from Apium graveolens (celery), Raphanus sativus (radish), Solanum tuberosum (potato), and Daucus carota (carrot) were most effective for promoting disappearance of pyrene within 40 days. Experiments with A. graveolens showed that plant culture in soil contaminated with pyrene or benzo[a]pyrene was as effective as addition of crushed root tissues. Comparison of the chemical compositions of the effective plants suggested that linoleic acid was the major substance that stimulated PAH degradation. This hypothesis was supported in experiments examining degradation of pyrene and benzo[a]pyrene in soil amended with linoleate, whereas linolenic and palmitic acids did not stimulate degradation within a 20 day period. Antibiotic inhibitor studies implicated gram positive bacteria as a predominant group responding to linoleic acid. These findings provide insight into the mechanisms by which plants enhance degradation of PAHs, and have practical application for remediation of PAH contaminated soils.

  18. Structural and Kinetic Characteristics of 1,4-Dioxane-Degrading Bacterial Consortia Containing the Phylum TM7.

    PubMed

    Nam, Ji-Hyun; Ventura, Jey-R S; Yeom, Ick Tae; Lee, Yongwoo; Jahng, Deokjin

    2016-11-28

    1,4-Dioxane-degrading bacterial consortia were enriched from forest soil (FS) and activated sludge (AS) using a defined medium containing 1,4-dioxane as the sole carbon source. These two enrichments cultures appeared to have inducible tetrahydrofuran/dioxane and propane degradation enzymes. According to qPCR results on the 16S rRNA and soluble di-iron monooxygenase genes, the relative abundances of 1,4-dioxane-degrading bacteria to total bacteria in FS and AS were 29.4% and 57.8%, respectively. For FS, the cell growth yields (Y), maximum specific degradation rate (Vmax), and half-saturation concentration (Km) were 0.58 mg-protein/mg-dioxane, 0.037 mg-dioxane/mg-protein∙h, and 93.9 mg/l, respectively. For AS, Y, Vmax, and Km were 0.34 mg-protein/mg-dioxane, 0.078 mg-dioxane/mg-protein∙h, and 181.3 mg/l, respectively. These kinetics data of FS and AS were similar to previously reported values. Based on bacterial community analysis on 16S rRNA gene sequences of the two enrichment cultures, the FS consortium was identified to contain 38.3% of Mycobacterium and 10.6% of Afipia, similar to previously reported literature. Meanwhile, 49.5% of the AS consortium belonged to the candidate division TM7, which has never been reported to be involved in 1,4-dioxane biodegradation. However, recent studies suggested that TM7 bacteria were associated with degradation of non-biodegradable and hazardous materials. Therefore, our results showed that previously unknown 1,4-dioxane-degrading bacteria might play an important role in enriched AS. Although the metabolic capability and ecophysiological significance of the predominant TM7 bacteria in AS enrichment culture remain unclear, our data reveal hidden characteristics of the TM7 phylum and provide a perspective for studying this previously uncultured phylotype.

  19. [Study on the degradation and transformation of nonylphenol in water containing algae].

    PubMed

    Peng, Zhang-E; Feng, Jin-Mei; He, Shu-Ying; Wu, Feng

    2012-10-01

    The photodegradation of nonylphenol induced by two common freshwater algae was investigated. The mechanism of nonylphenol photodegradation induced by algae was analyzed. The synergistic induction of nonylphenol degradation by algae and substances in water such as humic acid and ferric ions was also investigated. Results showed that the algae could induce the photodegradation of nonylphenol. The degradation of nonylphenol in water in the presence of algae, humic acid and ferric ions was obvious and the efficiency of degradation could reach 58% after 4 h illumination. Based on the results, it was speculated that the algae, humic acid and ferric ions system could produce more active oxygen after illumination, which could promote the photodegradation of the organic contaminants in water.

  20. In vitro degradation and mechanical integrity of calcium-containing magnesium alloys in modified-simulated body fluid.

    PubMed

    Kannan, M Bobby; Raman, R K Singh

    2008-05-01

    The successful applications of magnesium-based alloys as degradable orthopaedic implants are mainly inhibited due to their high degradation rates in physiological environment and consequent loss in the mechanical integrity. This study examines the degradation behaviour and the mechanical integrity of calcium-containing magnesium alloys using electrochemical techniques and slow strain rate test (SSRT) method, respectively, in modified-simulated body fluid (m-SBF). Potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) results showed that calcium addition enhances the general and pitting corrosion resistances of magnesium alloys significantly. The corrosion current was significantly lower in AZ91Ca alloy than that in AZ91 alloy. Furthermore, AZ91Ca alloy exhibited a five-fold increase in the surface film resistance than AZ91 alloy. The SSRT results showed that the ultimate tensile strength and elongation to fracture of AZ91Ca alloy in m-SBF decreased only marginally (approximately 15% and 20%, respectively) in comparison with these properties in air. The fracture morphologies of the failed samples are discussed in the paper. The in vitro study suggests that calcium-containing magnesium alloys to be a promising candidate for their applications in degradable orthopaedic implants, and it is worthwhile to further investigate the in vivo corrosion behaviour of these alloys.

  1. Fractionation of the organic matter contained in leachate resulting from two modes of landfilling: an indicator of waste degradation.

    PubMed

    Berthe, C; Redon, E; Feuillade, G

    2008-06-15

    Three experimental pilots were set up at the semi-industrial scale to assess the impact of leachate recirculation and Mechanical Biological Pre-treatment (MBP) before landfilling on the biological degradation of landfilled wastes. The organic matter contained in leachates resulting from these pilots has been used as an indicator of waste degradation. Fractionations were carried out (i) using XAD resins in order to divide the organic matter into several fractions according to the hydrophobic character of the molecules and (ii) using an ultrafiltration protocol to divide the organic matter into several fractions according to the apparent molecular weight of molecules. Three phases of degradation are determined according to the distribution of the organic matter and according to the humification rate. The humification process seems to be more rapid for MBP leachates than for Bioreactor leachate. These results were confirmed by the ultrafiltration results indicating that, to date, MBP leachates contain more molecules with a high molecular weight than Bioreactor leachate. However, this could be explained by an interruption of waste degradation due to an accumulation of volatile fatty acids.

  2. Enhanced methanogenic degradation of cellulose-containing sewage via fungi-methanogens syntrophic association in an anaerobic membrane bioreactor.

    PubMed

    Chen, Rong; Nie, Yulun; Tanaka, Nobuyuki; Niu, Qigui; Li, Qian; Li, Yu-You

    2017-09-08

    An anaerobic membrane bioreactor was configured for methanogenic degradation of cellulose-containing sewage. The degradation performance and microbial changes were evaluated under five hydraulic retention times (HRTs). The results indicated the methane production was largely enhanced with 92.6% efficiency of chemical oxygen demand (COD) converting to methane and 80% proportion of methane in produced biogas, meanwhile the biomass yield presented the fewest at the shortest HRT 8h. Enhanced methane production with decreased biomass yield was attributed to an association between fungi and methanogens. Microbial analysis showed fungi Basidiomycota and methanogen Methanoregula apparently established the association, especially Basidiomycota reaching 93% relative abundance at HRT 8h. Specific methanogenic activity (SMA) and biochemical methane potential (BMP) tests suggested the association was derived from H2 production by fungi and H2 consumption by methanogens, during the process of cellulose degradation. The methanogenic degradation of cellulose-containing sewage was markedly promoted via the fungi-methanogens syntrophic association. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Heme-Containing Metal-Organic Frameworks for the Oxidative Degradation of Chemical Warfare Agents

    DTIC Science & Technology

    2016-04-14

    stability of the oxo without sacrificing its inherent reactivity, we have synthesized a new framework featuring fluorinated groups in the ortho...especially suitable for the degradation of electrophilic phosphorous center, leading to the cleavage of P-S or P-O bond present in VX nerve agents

  4. Poly(lactide)-containing multifunctional nanoparticles: Synthesis, domain-selective degradation and therapeutic applicability

    NASA Astrophysics Data System (ADS)

    Samarajeewa, Sandani

    Construction of nanoassemblies from degradable components is desired for packaging and controlled release of active therapeutics, and eventual biodegradability in vivo. In this study, shell crosslinked micelles composed of biodegradable poly(lactide) (PLA) core were prepared by the self-assembly of an amphiphilic diblock copolymer synthesized by a combination of ring opening polymerization (ROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization. Enzymatic degradation of the PLA cores of the nanoparticles was achieved upon the addition of proteinase K (PK). Kinetic analyses and comparison of the properties of the nanomaterials as a function of degradation extent will be discussed. Building upon our findings from selective-excavation of the PLA core, enzyme- and redox-responsive nanoparticles were constructed for the encapsulation and stimuli-responsive release of an antitumor drug. This potent chemotherapeutic, otherwise poorly soluble in water was dispersed into aqueous solution by the supramolecular co-assembly with an amphiphilic block copolymer, and the release from within the core of these nanoparticles were gated by crosslinking the hydrophilic shell region with a reduction-responsive crosslinker. Enzyme- and reduction-triggered release behavior of the antitumor drug was demonstrated along with their remarkably high in vitro efficacy. As cationic nanoparticles are a promising class of transfection agents for nucleic acid delivery, in the next part of the study, synthetic methodologies were developed for the conversion of the negatively-charged shell of the enzymatically-degradable shell crosslinked micelles to positively-charged cationic nanoparticles for the complexation of nucleic acids. These degradable cationic nanoparticles were found to efficiently deliver and transfect plasmid DNA in vitro. The hydrolysis of the PLA core and crosslinkers of the nanocarriers may provide a mechanism for their programmed disassembly within

  5. A chimeric LDL receptor containing the cytoplasmic domain of the transferrin receptor is degraded by PCSK9.

    PubMed

    Holla, Øystein L; Strøm, Thea Bismo; Cameron, Jamie; Berge, Knut Erik; Leren, Trond P

    2010-02-01

    Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the extracellular domain of the low density lipoprotein receptor (LDLR) at the cell surface, and disrupts the normal recycling of the LDLR. However, the exact mechanism by which the LDLR is re-routed for lysosomal degradation remains to be determined. To clarify the role of the cytoplasmic domain of the LDLR for re-routing to the lysosomes, we have studied the ability of PCSK9 to degrade a chimeric receptor which contains the extracellular and transmembrane domains of the LDLR and the cytoplasmic domain of the transferrin receptor. These studies were performed in CHO T-REx cells stably transfected with a plasmid encoding the chimeric receptor and a novel assay was developed to study the effect of PCSK9 on the LDLR in these cells. Localization, function and stability of the chimeric receptor were similar to that of the wild-type LDLR. The addition of purified gain-of-function mutant D374Y-PCSK9 to the culture medium of stably transfected CHO T-REx cells showed that the chimeric receptor was degraded, albeit to a lower extent than the wild-type LDLR. In addition, a mutant LDLR, which has the three lysines in the intracellular domain substituted with arginines, was also degraded by D374Y-PCSK9. Thus, the mechanism for the PCSK9-mediated degradation of the LDLR does not appear to involve an interaction between the endosomal sorting machinery and LDLR-specific motifs in the cytoplasmic domain. Moreover, ubiquitination of lysines in the cytoplasmic domain does not appear to play a critical role in the PCSK9-mediated degradation of the LDLR.

  6. In vitro investigation of the follicular penetration of porcine ear skin using a nanoparticle-emulsion containing the antiseptic polihexanide In vitro investigation of the follicular penetration of porcine ear skin

    NASA Astrophysics Data System (ADS)

    Ulmer, M.; Patzelt, A.; Vergou, T.; Lademann, J.; Richter, H.; Kramer, A.; Müller, G.; Sterry, W.; Lange-Asschenfeldt, B.

    2012-05-01

    Earlier investigations regarding the distribution of the bacterial flora on the human skin demonstrate that the hair follicle acts as a bacterial reservoir, providing a quick source for secondary recontamination. These findings highlight the importance of the hair follicle as a target for modern antiseptics. In the present study, we have assessed the follicular penetration of a curcumin-labeled particle-associated antiseptic into porcine skin by laser scanning microscopy. Therefore, the follicular penetration depth of the curcumin-labeled particle-associated antiseptic was compared to the follicular penetration depth of curcumin-labeled particles without antiseptic. The investigation was performed in vitro using porcine skin biopsies. By superposition of the images acquired in the transmission and the fluorescent modus, it was possible to visualize the distribution of the fluorescent dye inside the hair follicles. Quantitative and qualitative results showed that both dispersions penetrated efficiently into the hair follicles. The average penetration depth of the particles with attached antiseptic polihexanide was significantly higher than that of particles without the attached antiseptic. Also, whilst very little sample preparation was needed, laser scanning microscopy was found to be an efficient tool to visualize the skin relief and in particular the hair follicle shaft and localize fluorescent markers within the skin tissue and hair follicles.

  7. Integration of nanofiltration and biological degradation of textile wastewater containing azo dye.

    PubMed

    Paździor, Katarzyna; Klepacz-Smółka, Anna; Ledakowicz, Stanisław; Sójka-Ledakowicz, Jadwiga; Mrozińska, Zdzisława; Zyłła, Renata

    2009-04-01

    The anaerobic biological azo dyes reduction process was successfully applied to decolourization of the concentrates from the nanofiltration treatment of real textile effluents. The anaerobic phase was followed by aerobic oxidation aimed at the destruction of the aromatic amine released from azo dye. In the first experiment sequential batch reactor (SBR) combining both the anaerobic and aerobic phase in one unit was used. In the second one the anaerobic stage was separated from the aerobic one. The anaerobic phase fulfilled its aim (decolourization) in both systems (over 90%). In opposite, the aromatic amine was completely degraded in the aerobic reactor (two-sludge system), whereas the orthanilic acid was not degraded (during the aerobic phase) in SBR reactor. The COD reduction was also higher in the two-sludge system than in SBR.

  8. Modification and restriction of T-even bacteriophages. In vitro degradation of deoxyribonucleic acid containing 5-hydroxymethylctosine.

    PubMed

    Fleischman, R A; Cambell, J L; Richardson, C C

    1976-03-25

    Using the single-stranded circular DNA of bacteriophage fd as template, double-stranded circular DNA has been prepared in vitro with either 5-hydroxymethylcytosine ([hmdC]DNA) or cytosine ([dC]DNA) in the product strand. Extracts prepared from Escherichia coli cells restrictive to T-even phage containing nonglucosylated DNA degrade [hmdC]DNA to acid-soluble material in vitro, but do not degrade [dC]dna. In contrast, extracts prepared from E. coli K12 rglA- rglB-, a strain permissive to T-even phage containing nonglucosylated DNA, do not degrade [hmdC]DNA or [dC]DNA. In addition, glucosylation of the [hmdC]DNA renders it resistant to degradation by extracts from restrictive strains. The conversion of [hmdC]DNA to acid-soluble material in vitro consists of an HmCyt-specific endonucleolytic cleavage requiring the presence of the RglB gene product to form a linear molecule, followed by a non-HmCyt-specific hydrolysis of the linear DNA to acid-soluble fragments, catalyzed in part by exonuclease V. The RglB protein present in extracts of E. coli K12 rglA- rglB+ has been purified 200-fold by complementation with extracts from E. coli K12 rglA- rglB-. The purified RglB protein does not contain detectable HmCyt-specific endonuclease or exonuclease activity. In vitro endonucleolytic cleavage of [hmdC]DNA thus requires additional factors present in cell extracts.

  9. Penetration equations

    SciTech Connect

    Young, C.W.

    1997-10-01

    In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.

  10. Biochemical and microscopic evidence for the internalization and degradation of heparin-containing mast cell granules by bovine endothelial cells

    SciTech Connect

    Atkins, F.M.; Friedman, M.M.; Metcalfe, D.D.

    1985-03-01

    Incubation of (/sup 35/S)heparin-containing mast cell granules with cultured bovine endothelial cells was followed by the appearance of /sup 35/S-granule-associated radioactivity within the endothelial cells and a decrease in radioactivity in the extracellular fluid. These changes occurred during the first 24 hours of incubation and suggested ingestion of the mast cell granules by the endothelial cells. Periodic electron microscopic examination of the monolayers confirmed this hypothesis by demonstrating apposition of the granules to the plasmalemma of endothelial cells, which was followed by the engulfment of the granules by cytoplasmic projections. Under light microscopic examination, mast cell granules within endothelial cells then appeared to undergo degradation. The degradation of (/sup 35/S)heparin in mast cell granules was demonstrated by a decrease in the amount of intracellular (/sup 35/S)heparin proteoglycan after 24 hours and the appearance of free (/sup 35/S)sulfate in the extracellular compartment. Intact endothelial cells were more efficient at degrading (/sup 35/S)heparin than were cell lysates or cell supernatants. These data provide evidence of the ability of endothelial cells to ingest mast cell granules and degrade native heparin that is presented as a part of the mast cell granule.

  11. Degradation of nitrobenzene-containing wastewater by carbon nanotubes immobilized nanoscale zerovalent iron

    NASA Astrophysics Data System (ADS)

    Jiao, Weizhou; Feng, Zhirong; Liu, Youzhi; Jiang, Huihui

    2016-07-01

    Nanoscaled zerovalent iron (NZVI)-multiwalled carbon nanotubes (CNTs) composite materials were prepared by in situ reduction of Fe2+ onto CNTs for nitrobenzene (NB) degradation. The morphologies and the composites of the prepared materials were characterized by SEM, TEM, and XRD. The results showed that the agglomeration of NZVI decreased with NZVI dispersed well onto the surfaces of CNTs, the particle size of NZVI on CNTs was about 20-50 nm. The BET surface areas of NZVI-CNTs was about 95.8 m2/g, which was 39 % higher than that of bare NZVI. For storage, the prepared NZVI-CNTs were concentrated into slurry and stored in situ as fresh slurry without drying. Contrast experiment results showed that the removal efficiency of NB by NZVI-CNTs fresh slurry was 30 % higher than that of vacuum-dried NZVI-CNTs, which indicates that storing in situ as fresh slurry can be an alternative strategy for nanoparticle storage. Batch experiment results showed that NB could be degraded to aniline by NZVI-CNTs rapidly, and the appropriate pH can be conducted at a relatively wide range from 2.0 to 9.0. The optimum mass ratio of iron-carbon was 1:1, and removal efficiency of NB by NZVI-CNTs with this mass ratio can achieve 100 % within 1 min. The degradation process of NB to intermediates was accelerated significantly by NZVI-CNTs, however, there was still a long term for the intermediates to transfer completely into the final product of aniline. The existence of CNTs can improve the formation of aniline through accelerating the electron transfer by forming microscopic galvanic cells with NZVI.

  12. Injectable, degradable, electroactive nanocomposite hydrogels containing conductive polymer nanoparticles for biomedical applications.

    PubMed

    Wang, Qinmei; Wang, Qiong; Teng, Wei

    2016-01-01

    Injectable electroactive hydrogels (eGels) are promising in regenerative medicine and drug delivery, however, it is still a challenge to obtain such hydrogels simultaneously possessing other properties including uniform structure, degradability, robustness, and biocompatibility. An emerging strategy to endow hydrogels with desirable properties is to incorporate functional nanoparticles in their network. Herein, we report the synthesis and characterization of an injectable hydrogel based on oxidized alginate (OA) crosslinking gelatin reinforced by electroactive tetraaniline-graft-OA nanoparticles (nEOAs), where nEOAs are expected to impart electroactivity besides reinforcement without significantly degrading the other properties of hydrogels. Assays of transmission electron microscopy, (1)H nuclear magnetic resonance, and dynamic light scattering reveal that EOA can spontaneously and quickly self-assemble into robust nanoparticles in water, and this nanoparticle structure can be kept at pH 3~9. Measurement of the gel time by rheometer and the stir bar method confirms the formation of the eGels, and their gel time is dependent on the weight content of nEOAs. As expected, adding nEOAs to hydrogels does not cause the phase separation (scanning electron microscopy observation), but it improves mechanical strength up to ~8 kPa and conductivity up to ~10(-6) S/cm in our studied range. Incubating eGels in phosphate-buffered saline leads to their further swelling with an increase of water content <6% and gradual degradation. When growing mesenchymal stem cells on eGels with nEOA content ≤14%, the growth curves and morphology of cells were found to be similar to that on tissue culture plastic; when implanting these eGels on a chick chorioallantoic membrane for 1 week, mild inflammation response appeared without any other structural changes, indicating their good in vitro and in vivo biocompatibility. With injectability, uniformity, degradability, electroactivity, relative

  13. Injectable, degradable, electroactive nanocomposite hydrogels containing conductive polymer nanoparticles for biomedical applications

    PubMed Central

    Wang, Qinmei; Wang, Qiong; Teng, Wei

    2016-01-01

    Injectable electroactive hydrogels (eGels) are promising in regenerative medicine and drug delivery, however, it is still a challenge to obtain such hydrogels simultaneously possessing other properties including uniform structure, degradability, robustness, and biocompatibility. An emerging strategy to endow hydrogels with desirable properties is to incorporate functional nanoparticles in their network. Herein, we report the synthesis and characterization of an injectable hydrogel based on oxidized alginate (OA) crosslinking gelatin reinforced by electroactive tetraaniline-graft-OA nanoparticles (nEOAs), where nEOAs are expected to impart electroactivity besides reinforcement without significantly degrading the other properties of hydrogels. Assays of transmission electron microscopy, 1H nuclear magnetic resonance, and dynamic light scattering reveal that EOA can spontaneously and quickly self-assemble into robust nanoparticles in water, and this nanoparticle structure can be kept at pH 3~9. Measurement of the gel time by rheometer and the stir bar method confirms the formation of the eGels, and their gel time is dependent on the weight content of nEOAs. As expected, adding nEOAs to hydrogels does not cause the phase separation (scanning electron microscopy observation), but it improves mechanical strength up to ~8 kPa and conductivity up to ~10−6 S/cm in our studied range. Incubating eGels in phosphate-buffered saline leads to their further swelling with an increase of water content <6% and gradual degradation. When growing mesenchymal stem cells on eGels with nEOA content ≤14%, the growth curves and morphology of cells were found to be similar to that on tissue culture plastic; when implanting these eGels on a chick chorioallantoic membrane for 1 week, mild inflammation response appeared without any other structural changes, indicating their good in vitro and in vivo biocompatibility. With injectability, uniformity, degradability, electroactivity, relative

  14. Degradation of carbon tetrachlorine in the presence of iron and sulphur containing compounds

    SciTech Connect

    Harms, S.; Lipczynska-Kochany, E.; Milburn, R.

    1995-12-01

    The effect of several sulphur compounds: sodium sulphate, sodium sulphide, ferrous sulphide, pyrite and organosulphonic acid on the kinetics of the iron (Fe{sup 0}) induced degradation of carbon tetrachloride was examined under aerobic conditions. It was observed that all of the sulphur compounds investigated significantly accelerated the reaction. The mechanisms of the processes studied as well as their possible influence of the efficiency of the iron-induced dehalogenation of pollutants, both in situ and in above-ground treatment are discussed.

  15. Biodegradable ferulic acid-containing poly(anhydride-ester): degradation products with controlled release and sustained antioxidant activity.

    PubMed

    Ouimet, Michelle A; Griffin, Jeremy; Carbone-Howell, Ashley L; Wu, Wen-Hsuan; Stebbins, Nicholas D; Di, Rong; Uhrich, Kathryn E

    2013-03-11

    Ferulic acid (FA) is an antioxidant and photoprotective agent used in biomedical and cosmetic formulations to prevent skin cancer and senescence. Although FA exhibits numerous health benefits, physicochemical instability leading to decomposition hinders its efficacy. To minimize inherent decomposition, a FA-containing biodegradable polymer was prepared via solution polymerization to chemically incorporate FA into a poly(anhydride-ester). The polymer was characterized using nuclear magnetic resonance and infrared spectroscopies. The molecular weight and thermal properties were also determined. In vitro studies demonstrated that the polymer was hydrolytically degradable, thus providing controlled release of the chemically incorporated bioactive with no detectable decomposition. The polymer degradation products were found to exhibit antioxidant and antibacterial activity comparable to that of free FA, and in vitro cell viability studies demonstrated that the polymer is noncytotoxic toward fibroblasts. This renders the polymer a potential candidate for use as a controlled release system for skin care formulations.

  16. Photo-triggered molecular release based on auto-degradable polymer-containing organic-inorganic hybrids.

    PubMed

    Okada, Hiroshi; Tanaka, Kazuo; Ohashi, Wataru; Chujo, Yoshiki

    2014-07-01

    The photo-triggered molecular release from the organic-inorganic polymer hybrids is presented in this manuscript. Initially, the preparation of the auto-degradable polymer is explained with the photo-cleavable group at the end of the polymer main-chain. The silica-based dye-loaded hybrids containing these polymers were fabricated. It was found that by UV irradiation, the end capping was removed, and then the auto-degradation occurs through the polymer main-chain. Finally, the molecular release of the loaded dyes was accomplished in various media by the UV irradiation. In particular, it was shown that both of hydrophobic and hydrophilic dyes can be applied in this system.

  17. Biodegradable Ferulic Acid-containing Poly(anhydride-ester): Degradation Products with Controlled Release and Sustained Antioxidant Activity

    PubMed Central

    Ouimet, Michelle A.; Griffin, Jeremy; Carbone-Howell, Ashley L.; Wu, Wen-Hsuan; Stebbins, Nicholas D.; Di, Rong; Uhrich, Kathryn E.

    2013-01-01

    Ferulic acid (FA) is an antioxidant and photoprotective agent used in biomedical and cosmetic formulations to prevent skin cancer and senescence. Although FA exhibits numerous health benefits, physicochemical instability leading to decomposition hinders its efficacy. To minimize inherent decomposition, a FA-containing biodegradable polymer was prepared via solution polymerization to chemically incorporate FA into a poly(anhydride-ester). The polymer was characterized using nuclear magnetic resonance and infrared spectroscopies. The molecular weight and thermal properties were also determined. In vitro studies demonstrated that the polymer was hydrolytically degradable, thus providing controlled release of the chemically incorporated bioactive with no detectable decomposition. The polymer degradation products were found to exhibit antioxidant and antibacterial activity comparable to free FA and in vitro cell viability studies demonstrated that the polymer is non-cytotoxic towards fibroblasts. This renders the polymer a potential candidate for use as a controlled release system for skin care formulations. PMID:23327626

  18. Microstructure degradation of YSZ in Ni/YSZ anodes of SOFC operated in phosphine-containing fuels

    SciTech Connect

    Chen, Yun; Chen, Song; Hackett, Gregory; Finklea, Harry; Zondlod, John; Celik, Ismail; Song, Xueyan; Gerdes, Kirk

    2013-03-07

    The interaction of trace (ppm) phosphine with the nickel/yttria stabilized zirconia (YSZ) anode of commercial solid oxide fuel cells has been investigated and evaluated for both synthesis gas and hydrogen fuels in an effort to examine P–Y reactions. The Ni poisoning effects reported in literature were confirmed and degradation was examined by electrochemical methods and post-test microstructural and chemical analyses. The results indicate that P-induced degradation rates and mechanisms are fuel dependent and that degradation of cells operated in synthesis gas (syngas) with phosphine is more severe than that of cells operated in hydrogen with phosphine. As reported in published literature, a cell operated in syngas containing 10 ppm phosphine demonstrated significant microstructural degradation within the Ni phase, including formation of Ni–P phases concentrated on the outer layer of the anode and significant pitting corrosion in the Ni grains. In this research, a previously undetected YPO{sub 4} phase is observed at the YSZ/YSZ/Ni triple grain junctions located at the interface with the YSZ electrolyte. Tetragonal YSZ (t-YSZ) and cubic-YSZ (c-YSZ) domains with sizes of several tens of nanometers are also newly observed along the Ni/YSZ interface. These observations contrast with data obtained for a cell operated in dry hydrogen with phosphine, where no YPO{sub 4} phase is observed and the alternating t-YSZ and c-YSZ domains at the Ni/YSZ interface are smaller with typical sizes of 5–10 nm. The data imply that electrolyte attack by P is a potentially debilitating mode of degradation in SOFC anodes, and that the associated reaction mechanisms and rates are worthy of further examination.

  19. Degradation behavior of Mg-based biomaterials containing different long-period stacking ordered phases

    PubMed Central

    Peng, Qiuming; Guo, Jianxin; Fu, Hui; Cai, Xuecheng; Wang, Yanan; Liu, Baozhong; Xu, Zhigang

    2014-01-01

    Long-period stacking ordered (LPSO) phases play an essential role in the development of magnesium alloys because they have a direct effect on mechanical and corrosion properties of the alloys. The LPSO structures are mostly divided to 18R and 14H. However, to date there are no consistent opinions about their degradation properties although both of them can improve mechanical properties. Herein we have successfully obtained two LPSO phases separately in the same Mg-Dy-Zn system and comparatively investigated the effect of different LPSO phases on degradation behavior in 0.9 wt.% NaCl solution. Our results demonstrate that a fine metastable 14H-LPSO phase in grain interior is more effective to improve corrosion resistance due to the presence of a homogeneous oxidation film and rapid film remediation ability. The outstanding corrosion resistant Mg-Dy-Zn based alloys with a metastable 14H-LPSO phase, coupled with low toxicity of alloying elements, are highly desirable in the design of novel Mg-based biomaterials, opening up a new avenue in the area of bio-Mg. PMID:24401851

  20. Degradation of zinc containing phosphate-based glass as a material for orthopedic tissue engineering.

    PubMed

    Qaysi, Mustafa Al; Petrie, Aviva; Shah, Rishma; Knowles, Jonathan C

    2016-10-01

    Phosphate-based glasses have been examined in many studies as a potential biomaterial for bone repair because of its degradation properties, which can be controlled and allow the release of various elements to promote osteogenic tissue growth. However most of these experiments studied either tertiary or quaternary glass systems. This study investigated a qinternary system that included titanium dioxide for degradation rate control and zinc that is considered to have a role in bone formation. Zinc and titanium phosphate glass discs of different compositions were melt synthesized and samples of each composition was tested for different physical, chemical and biological characteristics via density measurement, X-ray diffraction, differential thermal analysis, mass loss, ion release, scanning electron microscopy, biocompatibility studies via live/dead assays at three time points (day 1, 4, and 7). The results showed that the glass was amorphous and that the all thermal variables decreased as zinc oxide amount raised, mass loss as well as ion release increased as zinc oxide increased, and the maximum rise was with ZnO15. The cellular studies showed that all the formulation showed similar cytocompatibility properties with MG63 except ZnO15, which displayed cytotoxic properties and this was confirmed also by the scanning electron microscope images. In conclusion, replacing calcium oxide with zinc oxide in proportion less than 10 % can have a positive effect on bone forming cells.

  1. Liposomes containing glycocholate as potential oral insulin delivery systems: preparation, in vitro characterization, and improved protection against enzymatic degradation

    PubMed Central

    Niu, Mengmeng; Lu, Yi; Hovgaard, Lars; Wu, Wei

    2011-01-01

    Background: Oral delivery of insulin is challenging and must overcome the barriers of gastric and enzymatic degradation as well as low permeation across the intestinal epithelium. The present study aimed to develop a liposomal delivery system containing glycocholate as an enzyme inhibitor and permeation enhancer for oral insulin delivery. Methods: Liposomes containing sodium glycocholate were prepared by a reversed-phase evaporation method followed by homogenization. The particle size and entrapment efficiency of recombinant human insulin (rhINS)-loaded sodium glycocholate liposomes can be easily adjusted by tuning the homogenization parameters, phospholipid:sodium glycocholate ratio, insulin:phospholipid ratio, water:ether volume ratio, interior water phase pH, and the hydration buffer pH. Results: The optimal formulation showed an insulin entrapment efficiency of 30% ± 2% and a particle size of 154 ± 18 nm. A conformational study by circular dichroism spectroscopy and a bioactivity study confirmed the preserved integrity of rhINS against preparative stress. Transmission electron micrographs revealed a nearly spherical and deformed structure with discernable lamella for sodium glycocholate liposomes. Sodium glycocholate liposomes showed better protection of insulin against enzymatic degradation by pepsin, trypsin, and α-chymotrypsin than liposomes containing the bile salt counterparts of sodium taurocholate and sodium deoxycholate. Conclusion: Sodium glycocholate liposomes showed promising in vitro characteristics and have the potential to be able to deliver insulin orally. PMID:21822379

  2. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    SciTech Connect

    Bullen, D.B.; Gdowski, G.E. ); Weiss, H. )

    1988-06-01

    Three copper-based alloys, CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni), are being considered along with three austenitic candidates as possible materials for fabrication of containers for disposal of high-level radioactive waste. The waste will include spent fuel assemblies from reactors as well as high-level reprocessing wastes in borosilicate glass and will be sent to the prospective repository at Yucca Mountain, Nevada, for disposal. The containers must maintain mechanical integrity for 50 yr after emplacement to allow for retrieval of waste during the preclosure phase of repository operation. Containment is required to be substantially complete for up to 300 to 1000 yr. During the early period, the containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. The final closure joint will be critical to the integrity of the containers. This volume surveys the available data on the metallurgy of the copper-based candidate alloys and the welding techniques employed to join these materials. The focus of this volume is on the methods applicable to remote-handling procedures in a hot-cell environment with limited possibility of postweld heat treatment. The three copper-based candidates are ranked on the basis of the various closure techniques. On the basis of considerations regarding welding, the following ranking is proposed for the copper-based alloys: CDA 715 (best) > CDA 102 > CDA 613 (worst). 49 refs., 15 figs., 1 tab.

  3. Grain boundary degradation of YBCO superconductors sintered in CO{sub 2}-containing atmospheres

    SciTech Connect

    Balachandran, U.; Merkle, K.L.; Mundy, J.N.; Gao, Y.; Zhang, C.; Xu, D.; Selvaduray, G.

    1993-11-01

    The transport critical current density (J{sub c}) of YBCO superconductors decreased with increasing CO{sub 2} partial pressure in the sintering atmosphere and ultimately reached zero, even though magnetization measurements showed that the bulk of the samples with zero J{sub c} remained superconducting. The microstructure and composition of the samples was investigated by high resolution transmission electron microscopy and secondary-ion mass spectroscopy (SIMS). Microbeam SIMS indicated carbon segregation at grain boundaries (GBs). Approximately 10% of the GBs were coated with a thin layer of a second phase, deduced to be BaCuO{sub 2} and BaCu{sub 2}O{sub 2}. Near some grain boundaries, the structure was tetragonal within several tens of nm of the boundaries. The degradation of J{sub c} is discussed in terms of the partial pressure of CO{sub 2} and the processing temperatures. Detailed examination of GB microstructures is given in this paper.

  4. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    SciTech Connect

    Gdowski, G.E.; Bullen, D.B. )

    1988-08-01

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of containers for disposal of high-level radioactive waste. This waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, they must be retrievable from the disposal site. Shortly after the containers are emplaced in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of the high-level waste. This volume surveys the available data on oxidation and corrosion of the iron- to nickel-based austenitic materials (Types 304L and 316L stainless steels and Alloy 825) and the copper-based alloy materials (CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni)), which are the present candidates for fabrication of the containers. Studies that provided a large amount of data are highlighted, and those areas in which little data exists are identified. Examples of successful applications of these materials are given. On the basis of resistance to oxidation and general corrosion, the austenitic materials are ranked as follows: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is as follows: CDA 715 and CDA 613 (both best), and CDA 102 (worst). 110 refs., 30 figs., 13 tabs.

  5. Is there any difference in the biological impact of soluble and insoluble degradation products of iron-containing biomaterials?

    PubMed

    Fagali, Natalia S; Grillo, Claudia A; Puntarulo, Susana; Fernández Lorenzo de Mele, Mónica A

    2017-09-14

    The interactions that could be built between the biomaterials and tissue- microenvironments are very complex, especially in case of degradable metals that generate a broad variety of degradation products. The interfacial problems are particularly relevant for Fe-based materials that have been proposed for the development of biodegradable implants. The cell metabolism could be affected by the accumulation of insoluble Fe-containing degradation products that has been observed in vitro and in vivo as a coarse granular brownish material around the implant. However, the relative importance of each Fe-species (soluble and insoluble) on the cellular behavior of the surrounding cells, particularly on the generation of reactive species (RS), is not completely elucidated. The aim of this study is to evaluate the processes occurring at the Fe-biomaterial/cells interfacial region, and to discriminate the effects of soluble and insoluble corrosion products released by the bulk metal (Fe- microparticles (Fe(0)p) or Fe(0) ring) on the adjacent cells, mainly in relation to RS generation. With this purpose Fe(0)p and Fe(0) ring were incubated with fibroblast cells (BALB/c 3T3 line) for 24 and 48h periods. Then different techniques were used, such as the dichlorofluorescein diacetate assay (DCFH2-DA) for detection of RS, acridine orange dye for cell viability, total protein content determinations, Prussian Blue staining and TEM observations. To individualize the effects of soluble and insoluble species, independent experiments with Fe(3+)-salts were performed. Overall data indicate that RS generation by cells exposed to the degradation products of Fe-based biomaterials is more dependent on the presence of insoluble products than on soluble Fe species. Copyright © 2017. Published by Elsevier B.V.

  6. Temperature-related degradation and colour changes of historic paintings containing vivianite

    NASA Astrophysics Data System (ADS)

    Čermáková, Zdeňka; Švarcová, Silvie; Hradilová, Janka; Bezdička, Petr; Lančok, Adriana; Vašutová, Vlasta; Blažek, Jan; Hradil, David

    2015-04-01

    Temperature-related degradation of pure synthetic as well as partly oxidised natural vivianite has been studied by high-temperature X-ray diffraction (HT-XRD) covering the whole extent of the temperature-related stability of its structure. While temperatures around 70 °C are already damaging to vivianite, exposition to 160 °C results in complete amorphisation of both the vivianite and its oxidation products. As indicated by Mössbauer spectroscopy, temperature-induced oxidation of vivianite starts at 90 °C. To study the occurring structural as well as accompanying colour changes in more detail, model vivianite paint layer samples with different historic binders were prepared and subjected to increased temperatures. Exposition to 80 °C caused pronounced colour changes of all the samples: ground natural blue vivianite became grey - a colour change which has been described in actual works of art. Regarding the binders, the oil seemed to facilitate the transfer of heat to vivianite's grains. To simulate conditions of conservation treatment under which the painting is exposed to increased temperatures, oil-on-canvas mock-ups with vivianite were prepared and relined in a traditional way using iron. The treatment affected preferentially larger grains of vivianite; the micro-samples documented their change to grey, and their Raman spectra showed the change from vivianite to metavivianite.

  7. Temperature-related degradation and colour changes of historic paintings containing vivianite.

    PubMed

    Čermáková, Zdeňka; Švarcová, Silvie; Hradilová, Janka; Bezdička, Petr; Lančok, Adriana; Vašutová, Vlasta; Blažek, Jan; Hradil, David

    2015-04-05

    Temperature-related degradation of pure synthetic as well as partly oxidised natural vivianite has been studied by high-temperature X-ray diffraction (HT-XRD) covering the whole extent of the temperature-related stability of its structure. While temperatures around 70°C are already damaging to vivianite, exposition to 160°C results in complete amorphisation of both the vivianite and its oxidation products. As indicated by Mössbauer spectroscopy, temperature-induced oxidation of vivianite starts at 90°C. To study the occurring structural as well as accompanying colour changes in more detail, model vivianite paint layer samples with different historic binders were prepared and subjected to increased temperatures. Exposition to 80°C caused pronounced colour changes of all the samples: ground natural blue vivianite became grey--a colour change which has been described in actual works of art. Regarding the binders, the oil seemed to facilitate the transfer of heat to vivianite's grains. To simulate conditions of conservation treatment under which the painting is exposed to increased temperatures, oil-on-canvas mock-ups with vivianite were prepared and relined in a traditional way using iron. The treatment affected preferentially larger grains of vivianite; the micro-samples documented their change to grey, and their Raman spectra showed the change from vivianite to metavivianite.

  8. [Characteristics of nitrobenzene containing wastewater catalytic oxidation degradation by Fenton reagent].

    PubMed

    Wei, C; Chen, C; Wang, G; Ren, Y; Wu, C; Wu, H

    2001-09-01

    Through the alteration of the concentration of catalyst and oxidant, the rulers and dynamics of nitrobenzene oxidized by Fenton reagent in different concentrations were studied. The correlativity of the reaction time and relatively remain nitrobenzene was analyzed by the unitary linear regress equation. The result of the analysis proves that the coefficient was over the critical constant. The oxidation of nitrobenzene by Fenton reagent was in conformity with first-order dynamics model and the reaction rate constant was got at the same time. The idea, using the complex of Fe as the catalyst replacing Fe2+ in the Fenton Reaction, not only got a higher reaction velocity and efficiency, but also had a distinct exclusive to the degradation of nitrobenzene. The remove velocity of nitrobenzene was improved from 17.48 mg/(L.min) to 71.22 mg/(L.min), the remove rate in 5 minutes was from 9.74% to 91.79%. The nonhomogeneous catalyst made by the artificial zeolite with Fe-complex adsorbed had the same catalyzing behavior. In addition, ultraviolet radiation can also improves the Fenton reaction to some degree. These research works could demonstrate the good application potentiality of Fenton reagent in treating wastewater.

  9. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    SciTech Connect

    Bullen, D.B.; Gdowski, G.E. )

    1988-08-01

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of high-level radioactive-waste disposal containers. The waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The copper-based alloy materials are CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The austenitic materials are Types 304L and 316L stainless steels and Alloy 825. The waste-package containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr, and they must be retrievable from the disposal site during the first 50 yr after emplacement. The containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This volume surveys the available data on the phase stability of both groups of candidate alloys. The austenitic alloys are reviewed in terms of the physical metallurgy of the iron-chromium-nickel system, martensite transformations, carbide formation, and intermetallic-phase precipitation. The copper-based alloys are reviewed in terms of their phase equilibria and the possibility of precipitation of the minor alloying constituents. For the austenitic materials, the ranking based on phase stability is: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is: CDA 102 (oxygen-free copper) (best), and then both CDA 715 and CDA 613. 75 refs., 24 figs., 6 tabs.

  10. Strontium- and calcium-containing, titanium-stabilised phosphate-based glasses with prolonged degradation for orthopaedic tissue engineering.

    PubMed

    Al Qaysi, Mustafa; Walters, Nick J; Foroutan, Farzad; Owens, Gareth J; Kim, Hae-Won; Shah, Rishma; Knowles, Jonathan C

    2015-09-01

    Strontium- and calcium-releasing, titanium-stabilised phosphate-based glasses with a controlled degradation rate are currently under development for orthopaedic tissue engineering applications. Ca and/or Sr were incorporated at varying concentrations in quaternary phosphate-based glasses, in order to promote osteoinduction. Ti was incorporated at a fixed concentration in order to prolong degradation. Glasses of the general formula (P2O5)-(Na2O)-(TiO2)-(CaO)-(SrO) were prepared via the melt-quench technique. The materials were characterised by energy-dispersive X-ray spectroscopy, X-ray diffraction, (31)P magic angle spinning nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential thermal analysis and density determination. The dissolution rate in distilled water was determined by measuring mass loss, ion release and pH change over a two-week period. In addition, the cytocompatibility and alkaline phosphatase activity of an osteoblast-like cell line cultured on the surface of glass discs was assessed. The glasses were shown to be amorphous and contained Q(1), Q(2) and Q(3) species. Fourier transform infrared spectroscopy revealed small changes in the glass structure as Ca was substituted with Sr and differential thermal analysis confirmed a decrease in crystallisation temperature with increasing Sr content. Degradation and ion release studies also showed that mass loss was positively correlated with Sr content. These results were attributed to the lower electronegativity of Sr in comparison to Ca favouring the formation of phosphate-based mineral phases. All compositions supported cell proliferation and survival and induced at least 2.3-fold alkaline phosphatase activity relative to the control. Glass containing 17.5 mol% Sr had 3.6-fold greater alkaline phosphatase activity than the control. The gradual release of Ca and Sr supported osteoinduction, indicating their potential suitability in orthopaedic tissue engineering applications.

  11. Strontium- and calcium-containing, titanium-stabilised phosphate-based glasses with prolonged degradation for orthopaedic tissue engineering

    PubMed Central

    Al Qaysi, Mustafa; Walters, Nick J; Foroutan, Farzad; Owens, Gareth J; Kim, Hae-Won; Shah, Rishma

    2015-01-01

    Strontium- and calcium-releasing, titanium-stabilised phosphate-based glasses with a controlled degradation rate are currently under development for orthopaedic tissue engineering applications. Ca and/or Sr were incorporated at varying concentrations in quaternary phosphate-based glasses, in order to promote osteoinduction. Ti was incorporated at a fixed concentration in order to prolong degradation. Glasses of the general formula (P2O5)–(Na2O)–(TiO2)–(CaO)–(SrO) were prepared via the melt-quench technique. The materials were characterised by energy-dispersive X-ray spectroscopy, X-ray diffraction, 31P magic angle spinning nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential thermal analysis and density determination. The dissolution rate in distilled water was determined by measuring mass loss, ion release and pH change over a two-week period. In addition, the cytocompatibility and alkaline phosphatase activity of an osteoblast-like cell line cultured on the surface of glass discs was assessed. The glasses were shown to be amorphous and contained Q1, Q2 and Q3 species. Fourier transform infrared spectroscopy revealed small changes in the glass structure as Ca was substituted with Sr and differential thermal analysis confirmed a decrease in crystallisation temperature with increasing Sr content. Degradation and ion release studies also showed that mass loss was positively correlated with Sr content. These results were attributed to the lower electronegativity of Sr in comparison to Ca favouring the formation of phosphate-based mineral phases. All compositions supported cell proliferation and survival and induced at least 2.3-fold alkaline phosphatase activity relative to the control. Glass containing 17.5 mol% Sr had 3.6-fold greater alkaline phosphatase activity than the control. The gradual release of Ca and Sr supported osteoinduction, indicating their potential suitability in orthopaedic tissue engineering applications

  12. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers; Overview

    SciTech Connect

    Farmer, J.C.; McCright, R.D.; Kass, J.N.

    1988-06-01

    Three iron- to nickel-based austenitic alloys and three copper-based alloys are being considered as candidate materials for the fabrication of high-level radioactive-waste disposal containers. The austenitic alloys are Types 304L and 316L stainless steels and the high-nickel material Alloy 825. The copper-based alloys are CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). Waste in the forms of both spent fuel assemblies from reactors and borosilicate glass will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides will result in the generation of substantial heat and gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including undesirable phase transformations due to a lack of phase stability; atmospheric oxidation; general aqueous corrosion; pitting; crevice corrosion; intergranular stress corrosion cracking; and transgranular stress corrosion cracking. Problems specific to welds, such as hot cracking, may also occur. A survey of the literature has been prepared as part of the process of selecting, from among the candidates, a material that is adequate for repository conditions. The modes of degradation are discussed in detail in the survey to determine which apply to the candidate alloys and the extent to which they may actually occur. The eight volumes of the survey are summarized in Sections 1 through 8 of this overview. The conclusions drawn from the survey are also given in this overview.

  13. Gradual degradation of concrete fiber containers and preliminary Safety analysis for the Slovak near-surface repository

    SciTech Connect

    Duran, Juraj

    2007-07-01

    Available in abstract form only. Full text of publication follows: National Radioactive Waste Repository will be used for safe disposal of low and intermediate-level radioactive wastes in Mochovce, Slovak Republic. The Preliminary Safety Analysis Report (PSAR) has developed a conceptual model that strongly overestimated radiological exposures for the Normal Evolution Scenario (NES). Radioactive waste management required additional measures for safe disposal of radioactive waste to minimize the potential consequence to the workers and the public. Use of Fiber Reinforced Containers (FRC) is proposed to enhance the performance of the potential repository for safe disposal of radioactive waste and reduce the probability of exposure. This paper contains the description of models, methods, results from experimental measurements and input data, which were used for probabilistic calculations of the lifetime FRC. The Cumulative Distribution Function (CDF) for the FRC lifetime was used to modify the conceptual model for NES. The model assumed gradual degradation of the FRC and gradual intrusion of water to the repository volume. These assumptions are in contrary to the ones in the PSAR that assumed instantaneous degradation of the FRC and instantaneous fill-up of the repository volume. The model showed that the new assumptions resulted in less radiological consequences, which allows for final design modifications of the repository. (author)

  14. Radiation degradation behavior of chlorine-containing vinyl copolymers. Search for improved electron-beam resists

    SciTech Connect

    Helbert, J.N.; Poindexter, E.H.; Pittman, C.U. Jr.; Chen, C.Y.

    1980-06-01

    Vinyl copolymers with high radiation degradation sensitivity have been synthesized by copolymerizing vinylidene chloride (VDC), CH/sub 2/ = CCl/sub 2/, with methyl methacrylate (MMA), methacrylonitrile, methyl ..cap alpha..-chloroacrylate, and dimethyl itaconate using emulsion techniques. In addition, copolymers of methyl ..cap alpha..-chloroacrylate with methyl methacrylate and poly(..cap alpha..-chloroacrylonitrile) were studied. Introduction of vinylidene chloride into methyl methacrylate polymers caused a sharp increase in G/sub s/ even at relatively low VDC incorporation. Upon 29% VDC incorporation, the G/sub s/ value increased from 1.3 (homopolymer of MMA) to 3.4. G/sub s/ was found to be a linear function of copolymer content for several systems, but G/sub x/ was not. At higher VDC levels, the increase in G/sub s/ was countered by increases in G/sub x/. At lower VDC levels, G/sub x/ was suppressed below the values predicted by a linear G/sub x/ dependence on composition for such systems as VDC/MMA, MCA/MMA, and ..cap alpha..-chloroacrylonitrile/MMA. The VDC/MMA copolymer (29% VDC) gave a sensitivity of 4.0 x 10/sup -5/ C/cm/sup 2/ to electron beam exposure using the 0% unexposed resist thickness loss criterion and is 2 to 3 times more sensitive than PMMA. Poly(..cap alpha..-chloroacrylonitrile) is a negative resist with a sensitivity of 5 x 10/sup -5/ C/cm/sup 2/ using one-micron line images for testing.

  15. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers

    SciTech Connect

    Vinson, D.W.; Nutt, W.M.; Bullen, D.B.

    1995-06-01

    Oxidation and atmospheric corrosion data suggest that addition of Cr provides the greatest improvement in oxidation resistance. Cr-bearing cast irons are resistant to chloride environments and solutions containing strongly oxidizing constituents. Weathering steels, including high content and at least 0.04% Cu, appear to provide adequate resistance to oxidation under temperate conditions. However, data from long-term, high-temperature oxidation studies on weathering steels were not available. From the literature, it appears that the low alloy steels, plain carbon steels, cast steels, and cast irons con-ode at similar rates in an aqueous environment. Alloys containing more than 12% Cr or 36% Ni corrode at a lower rate than plain carbon steels, but pitting may be worse. Short term tests indicate that an alloy of 9Cr-1Mo may result in increased corrosion resistance, however long term data are not available. Austenitic cast irons show the best corrosion resistance. A ranking of total corrosion performance of the materials from most corrosion resistant to least corrosion resistant is: Austenitic Cast Iron; 12% Cr = 36% Ni = 9Cr-1Mo; Carbon Steel = Low Alloy Steels; and Cast Iron. Since the materials to be employed in the Advanced Conceptual Design (ACD) waste package are considered to be corrosion allowance materials, the austenitic cast irons, high Cr steels, high Ni steels and the high Cr-Mo steels should not be considered as candidates for the outer containment barrier. Based upon the oxidation and corrosion data available for carbon steels, low alloy steels, and cast irons, a suitable list of candidate materials for a corrosion allowance outer barrier for an ACD waste package could include, A516, 2.25%Cr -- 1%Mo Steel, and A27.

  16. Characterization of smart auto-degradative hydrogel matrix containing alginate lyase to enhance levofloxacin delivery against bacterial biofilms.

    PubMed

    Islan, German A; Dini, Cecilia; Bartel, Laura C; Bolzán, Alejandro D; Castro, Guillermo R

    2015-12-30

    The aim of the present work is the characterization of smart auto-degradable microspheres composed of calcium alginate/high methoxylated pectin containing an alginate lyase (AL) from Sphingobacterium multivorum and levofloxacin. Microspheres were prepared by ionotropic gelation containing AL in its inactive form at pH 4.0. Incubation of microspheres in Tris-HCl and PBS buffers at pH 7.40 allowed to establish the effect of ion-chelating phosphate on matrix erodability and suggested an intrinsically activation of AL by turning the pH close to neutrality. Scanning electron and optical microscopies revealed the presence of holes and surface changes in AL containing microspheres. Furthermore, texturometric parameters, DSC profiles and swelling properties were showing strong changes in microspheres properties. Encapsulation of levofloxacin into microspheres containing AL showed 70% efficiency and 35% enhancement of antimicrobial activity against Pseudomonas aeruginosa biofilm. Levofloxacin release from microspheres was not changed at acidic pH, but was modified at neutral pH in presence of AL. Advantageously, only gel matrix debris were detectable after overnight incubation, indicating an autodegradative gel process activated by the pH. Absence of matrix cytotoxicity and a reduction of the levofloxacin toxicity after encapsulation were observed in mammalian CHO-K1 cell cultures. These properties make the system a potent and versatile tool for antibiotic oral delivery targeted to intestine, enhancing the drug bioavailability to eradicate bacterial biofilm and avoiding possible intestinal obstructions.

  17. Mechanism of the alkali degradation of (6-4) photoproduct-containing DNA.

    PubMed

    Arichi, Norihito; Inase, Aki; Eto, Sachise; Mizukoshi, Toshimi; Yamamoto, Junpei; Iwai, Shigenori

    2012-03-21

    The (6-4) photoproduct is one of the major damaged bases produced by ultraviolet light in DNA. This lesion is known to be alkali-labile, and strand breaks occur at its sites when UV-irradiated DNA is treated with hot alkali. We have analyzed the product obtained by the alkali treatment of a dinucleoside monophosphate containing the (6-4) photoproduct, by HPLC, NMR spectroscopy, and mass spectrometry. We previously found that the N3-C4 bond of the 5' component was hydrolyzed by a mild alkali treatment, and the present study revealed that the following reaction was the hydrolysis of the glycosidic bond at the 3' component. The sugar moiety of this component was lost, even when a 3'-flanking nucleotide was not present. Glycosidic bond hydrolysis was also observed for a dimer and a trimer containing 5-methyl-2-pyrimidinone, which was used as an analog of the 3' component of the (6-4) photoproduct, and its mechanism was elucidated. Finally, the alkali treatment of a tetramer, d(GT(6-4)TC), yielded 2'-deoxycytidine 5'-monophosphate, while 2'-deoxyguanosine 3'-monophosphate was not detected. This result demonstrated the hydrolysis of the glycosidic bond at the 3' component of the (6-4) photoproduct and the subsequent strand break by β-elimination. It was also shown that the glycosidic bond at the 3' component of the Dewar valence isomer was more alkali-labile than that of the (6-4) photoproduct.

  18. Ex vivo skin permeation and penetration of nonivamide from and in vivo skin tolerability of film-forming formulations containing porous silica.

    PubMed

    Heck, Rouven; Lukić, Milica Ž; Savić, Snežana D; Daniels, Rolf; Lunter, Dominique J

    2017-08-30

    The purpose of this study was to evaluate skin permeation and penetration of nonivamide which has been formulated in novel film-forming formulations (FFFs). These formulations aim to prolong the availability of capsaicinoids which are used in long-term treatment of chronic pruritus. An oily solution of nonivamide was loaded into porous silica particles which then were suspended in an aqueous dispersion of a sustained release polymer. Permeation and penetration experiments were performed ex vivo with postauricular porcine skin using modified Franz diffusion cells. The penetrated drug amount was assessed ex vivo by skin surface biopsy followed by cryo-sectioning. Furthermore, in vivo skin irritation experiments were performed to compare the potential skin irritation caused by the FFFs to conventionally used semi-solid formulations. Permeation rates of nonivamide from FFF through the skin are comparable to that from clinically used immediate release formulations. This elucidates the therapeutic safety profile of the novel FFF. Penetration studies confirmed the prolonged drug availability at the site of action. FFFs were found not to irritate the skin of healthy volunteers. FFFs with sustained nonivamide penetration represent safe and easy-to-use formulations. They therefore may improve the treatment of chronic pruritus with capsaicinoids by enhancing patient compliance through a sustained release regime. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Abundance and Diversity of Dockerin-Containing Proteins in the Fiber-Degrading Rumen Bacterium, Ruminococcus flavefaciens FD-1

    PubMed Central

    Flint, Harry J.; Travis, Anthony J.; Jindou, Sadanari; Borovok, Ilya; Lamed, Raphael; Bayer, Edward A.; Henrissat, Bernard; Coutinho, Pedro M.; Antonopoulos, Dion A.; Berg Miller, Margret E.; White, Bryan A.

    2010-01-01

    Background The cellulosome is a multi-enzyme machine, which plays a key role in the breakdown of plant cell walls in many anaerobic cellulose-degrading microorganisms. Ruminococcus flavefaciens FD-1, a major fiber-degrading bacterium present in the gut of herbivores, has the most intricate cellulosomal organization thus far described. Cellulosome complexes are assembled through high-affinity cohesin-dockerin interactions. More than two-hundred dockerin-containing proteins have been identified in the R. flavefaciens genome, yet the reason for the expansion of these crucial cellulosomal components is yet unknown. Methodology/Principal Findings We have explored the full spectrum of 222 dockerin-containing proteins potentially involved in the assembly of cellulosome-like complexes of R. flavefaciens. Bioinformatic analysis of the various dockerin modules showed distinctive conservation patterns within their two Ca2+-binding repeats and their flanking regions. Thus, we established the conceptual framework for six major groups of dockerin types, according to their unique sequence features. Within this framework, the modular architecture of the parent proteins, some of which are multi-functional proteins, was evaluated together with their gene expression levels. Specific dockerin types were found to be associated with selected groups of functional components, such as carbohydrate-binding modules, numerous peptidases, and/or carbohydrate-active enzymes. In addition, members of other dockerin groups were linked to structural proteins, e.g., cohesin-containing proteins, belonging to the scaffoldins. Conclusions/Significance This report profiles the abundance and sequence diversity of the R. flavefaciens FD-1 dockerins, and provides the molecular basis for future understanding of the potential for a wide array of cohesin-dockerin specificities. Conserved differences between dockerins may be reflected in their stability, function or expression within the context of the parent

  20. Raman spectroscopy and capillary zone electrophoresis for the analysis of degradation processes in commercial effervescent tablets containing acetylsalicylic acid and ascorbic acid.

    PubMed

    Neuberger, Sabine; Jooß, Kevin; Flottmann, Dirk; Scriba, Gerhard; Neusüß, Christian

    2017-02-05

    In order to ensure the stability of pharmaceutical products appropriate manufacturing and storage conditions are required. In general, the degradation of active pharmaceutical ingredients (APIs) and subsequent formation of degradation products affect the pharmaceutical quality. Thus, a fast and effective detection and characterization of these substances is mandatory. Here, the applicability of Raman spectroscopy and CZE for the characterization of the degradation of effervescent tablets containing acetylsalicylic acid (ASA) and ascorbic acid (AA) was evaluated. Therefore, a degradation study was performed analyzing tablets from two different manufacturers at varying conditions (relative humidity (RH) 33%, 52% and 75% at 30°C). Raman spectroscopy combined with principal component analysis could be successfully applied for the fast and easy discrimination of non-degraded and degraded effervescent tablets after a storage period of approximately 24h (RH 52%). Nevertheless, a clear identification or quantification of APIs and degradation products within the analyzed tablets was not possible, i.a. due to missing reference materials. CZE-UV enabled the quantification of the APIs (ASA, AA) and related degradation products (salicylic acid (SA); semi-quantitative also mono- and diacetylated AA) within the complex tablet mixtures. The higher the RH, the faster the degradation of ASA and AA as well as the formation of the degradation products. Mono- and diacetylated AA are major primary degradation products of AA for the applied effervescent tablets. A significant degradation of the APIs was detected earlier by CZE (6-12h, RH 52%) than by Raman spectroscopy. Summarized, Raman spectroscopy is well-suited as quick test to detect degradation of these tablets and CZE can be utilized for further detailed characterization and quantification of specific APIs and related degradation products.

  1. A CUL-2 ubiquitin ligase containing three FEM proteins degrades TRA-1 to regulate C. elegans sex determination.

    PubMed

    Starostina, Natalia G; Lim, Jae-min; Schvarzstein, Mara; Wells, Lance; Spence, Andrew M; Kipreos, Edward T

    2007-07-01

    In Caenorhabditis elegans, the Gli-family transcription factor TRA-1 is the terminal effector of the sex-determination pathway. TRA-1 activity inhibits male development and allows female fates. Genetic studies have indicated that TRA-1 is negatively regulated by the fem-1, fem-2, and fem-3 genes. However, the mechanism of this regulation has not been understood. Here, we present data that TRA-1 is regulated by degradation mediated by a CUL-2-based ubiquitin ligase complex that contains FEM-1 as the substrate-recognition subunit, and FEM-2 and FEM-3 as cofactors. CUL-2 physically associates with both FEM-1 and TRA-1 in vivo, and cul-2 mutant males share feminization phenotypes with fem mutants. CUL-2 and the FEM proteins negatively regulate TRA-1 protein levels in C. elegans. When expressed in human cells, the FEM proteins interact with human CUL2 and induce the proteasome-dependent degradation of TRA-1. This work demonstrates that the terminal step in C. elegans sex determination is controlled by ubiquitin-mediated proteolysis.

  2. Synthesis of cyclotriphosphazene-containing polymeric nanotubes and their use as metal-free photocatalysts for methylene blue degradation

    NASA Astrophysics Data System (ADS)

    Li, Zhenke; Wang, Guanghui; Liang, Chen; Zhang, Aiqing

    2015-08-01

    Highly cross-linked, organic-inorganic hybrid polymer nanotubes with primary amine groups on the surface have been successfully prepared through a facile polycondensation of hexachlorocyclotriphosphazene and melamine in absence of any surfactants or template agents. Then, these nanotubes were used as visible light photocatalysts for the degradation of methylene blue (MB) in water and the physicochemical properties of catalysts were characterized by several techniques. The as-synthesized nanotubes were closed at one end with a micrometer-scale in length (about 3-10 μm), 200-300 nm in the diameter, and the inner diameters of the two ends of each nanotube was 100-200 nm and 5-10 nm, respectively. A large amount of free radicals (rad OH) were generated in aqueous phase under visible light irradiation, which can photocatalytically oxidize and eventually mineralize. And, the progress of degradation was similar with semiconductor materials. The simple preparation method and photocatalytic performance of the cyclotriphosphazene-containing polymeric nanotubes represent an important step towards photocatalytic reaction in general where artificial conjugated polymer semiconductors can be used as energy transducers.

  3. A CUL-2 ubiquitin ligase containing three FEM proteins degrades TRA-1 to regulate C. elegans sex determination

    PubMed Central

    Starostina, Natalia G.; Lim, Jae-min; Schvarzstein, Mara; Wells, Lance; Spence, Andrew M.; Kipreos, Edward T.

    2007-01-01

    Summary In Caenorhabditis elegans, the Gli-family transcription factor TRA-1 is the terminal effector of the sex determination pathway. TRA-1 activity inhibits male development and allows female fates. Genetic studies have indicated that TRA-1 is negatively regulated by the fem-1, fem-2, and fem-3 genes. However, the mechanism of this regulation has not been understood. Here, we present data that TRA-1 is regulated by degradation mediated by a CUL-2-based ubiquitin ligase complex that contains FEM-1 as the substrate-recognition subunit, and FEM-2 and FEM-3 as cofactors. CUL-2 physically associates with both FEM-1 and TRA-1 in vivo, and cul-2 mutant males share feminization phenotypes with fem mutants. CUL-2 and the FEM proteins negatively regulate TRA-1 protein levels in C. elegans. When expressed in human cells, the FEM proteins interact with human CUL2 and induce the proteasome-dependent degradation of TRA-1. This work demonstrates that the terminal step in C. elegans sex determination is controlled by ubiquitin-mediated proteolysis. PMID:17609115

  4. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers. Final report

    SciTech Connect

    Vinson, D.W.; Bullen, D.B.

    1995-09-22

    One of the most significant factors impacting the performance of waste package container materials under repository relevant conditions is the thermal environment. This environment will be affected by the areal power density of the repository, which is dictated by facility design, and the dominant heat transfer mechanism at the site. The near-field environment will evolve as radioactive decay decreases the thermal output of each waste package. Recent calculations (Buscheck and Nitao, 1994) have addressed the importance of thermal loading conditions on waste package performance at the Yucca Mountain site. If a relatively low repository thermal loading design is employed, the temperature and relative humidity near the waste package may significantly affect the degradation of corrosion allowance barriers due to moist air oxidation and radiolytically enhanced corrosion. The purpose this report is to present a literature review of the potential degradation modes for moderately corrosion resistant nickel copper and nickel based candidate materials that may be applicable as alternate barriers for the ACD systems in the Yucca Mountain environment. This report presents a review of the corrosion of nickel-copper alloys, summaries of experimental evaluations of oxidation and atmospheric corrosion in nickel-copper alloys, views of experimental studies of aqueous corrosion in nickel copper alloys, a brief review of galvanic corrosion effects and a summary of stress corrosion cracking in these alloys.

  5. Degradation of dimethyl-sulfoxide-containing wastewater using airlift bioreactor by polyvinyl-alcohol-immobilized cell beads.

    PubMed

    He, Sin-Yi; Lin, Yun-Huin; Hou, Kuan-Yun; Hwang, Sz-Chwun John

    2011-05-01

    Airlift bioreactor containing polyvinyl-alcohol-immobilized cell beads was investigated for its capability of biodegradation of dimethyl sulfoxide (DMSO) in term of sludge characteristics including the strategy of acclimation with sucrose and the protection of microorganism from poisoning of DMSO by PVA cell beads. Media condition with sucrose at 50 mg L(-1) was beneficial to the biodegradation of DMSO in the fresh PVA entrapped-sludge, but became insignificant in the acclimated one as for tolerance of DMSO toxicity. The removal efficiency of DMSO had the highest rate at 1.42-kg DMSO per kilogram of suspended solid per day after series acclimation batches in the oxygen-enriched airlift bioreactor treated with the 1187.4 mg L(-1) of DMSO. Microbial consortium was required for the complete biodegradation of DMSO without any dimethyl sulfide produced. Pseudomonas sp. W1, excreting extracellular monooxygenase identified by indole, was isolated to be one of the most effective DMSO-degrading microorganism in our airlift bioreactor.

  6. Photocatalytic degradation of commercial methyl parathion in aqueous suspension containing La-doped TiO2 nanoparticles.

    PubMed

    Chen, Hao; Shen, Min; Chen, Ruiwen; Dai, Ke; Peng, Tianyou

    2011-10-01

    The photocatalytic degradation of a commercial methyl parathion (MP) under UV irradiation was investigated in aqueous suspension containing lanthanum-doped mesoporous TiO2 nanoparticles (La/m-TiO2) as photocatalyst. The rate of photodecomposition of MP was measured using UV-Vis spectrophotometry, and its mineralization was followed using ion chromatography (IC). The identification of possible intermediate products was carried out using several powerful analytical techniques such as gas chromatography-pulsed flame photometric detector (GC-PFPD) and high performance liquid chromatography-mass spectroscopy (HPLC-MS). Under our conditions, complete disappearance of 20 mg/L of MP occurred within 2 h of illumination, whereas complete mineralization of MP was not achieved through IC analysis. There was a single intermediate product found in the research, which was identified to be methyl paraoxon, owing to the substitution of S by the O atom in the MP molecule. Based on the experimental facts, it is concluded that MP was mainly attacked not by OH radicals but photo-generated holes (h+), resulting from the good adsorption of MP on the catalyst surfaces due to the enhanced adsorption by La doping.

  7. The SPRY domain–containing SOCS box protein SPSB2 targets iNOS for proteasomal degradation

    PubMed Central

    Kuang, Zhihe; Lewis, Rowena S.; Curtis, Joan M.; Zhan, Yifan; Saunders, Bernadette M.; Babon, Jeffrey J.; Kolesnik, Tatiana B.; Low, Andrew; Masters, Seth L.; Willson, Tracy A.; Kedzierski, Lukasz; Yao, Shenggen; Handman, Emanuela

    2010-01-01

    Inducible nitric oxide (NO) synthase (iNOS; NOS2) produces NO and related reactive nitrogen species, which are critical effectors of the innate host response and are required for the intracellular killing of pathogens such as Mycobacterium tuberculosis and Leishmania major. We have identified SPRY domain–containing SOCS (suppressor of cytokine signaling) box protein 2 (SPSB2) as a novel negative regulator that recruits an E3 ubiquitin ligase complex to polyubiquitinate iNOS, resulting in its proteasomal degradation. SPSB2 interacts with the N-terminal region of iNOS via a binding interface on SPSB2 that has been mapped by nuclear magnetic resonance spectroscopy and mutational analyses. SPSB2-deficient macrophages showed prolonged iNOS expression, resulting in a corresponding increase in NO production and enhanced killing of L. major parasites. These results lay the foundation for the development of small molecule inhibitors that could disrupt the SPSB–iNOS interaction and thus prolong the intracellular lifetime of iNOS, which may be beneficial in chronic and persistent infections. PMID:20603330

  8. Electrospun biodegradable calcium containing poly(ester-urethane)urea: synthesis, fabrication, in vitro degradation, and biocompatibility evaluation.

    PubMed

    Nair, Priya A; Ramesh, P

    2013-07-01

    In this work an in vitro degradable poly(ester-urethane)urea (PEUU) was synthesized using polycaprolactone diol, hexamethylene diisocyanate, and calcium salt of p-aminobenzoic acid. The synthesized polymer was characterized by (1) H-NMR and FTIR spectroscopy and viscosity studies. Scaffolds having random micro fibrous structures were fabricated from PEUU by electrospinning process. The thermal properties of the scaffold were evaluated by thermogravimetric analysis and dynamic mechanical analysis. The mechanical property evaluation showed that the scaffold possess sufficiently high tensile strength of 16 MPa. The in vitro degradation studies of the electrospun scaffold were carried out in phosphate buffer saline for 6 months. The average mass loss of the scaffold after 6 months of hydrolytic degradation was 25%. FTIR spectroscopy study confirmed the degradation of the PEUU from decrease in intensity of 1400 cm(-1) peak corresponding to ionic carboxylate group. Presence of amine group and calcium ions in the degradation medium further confirmed the degradation of the hard segment in the hydrolytic medium. The mechanical property evaluation of the scaffold indicated a gradual decrease in tensile strength and modulus whereas percentage elongation of the scaffold increases with time of in vitro degradation. The morphological evaluation of the scaffold after degradation by SEM shows evidence of broken fibers and pores in the scaffold. Preliminary in vitro cytotoxicity test demonstrated that both the material and the degradation products were noncytotoxic in nature and the material showed good proliferation to L-929 cells.

  9. Kinetics of quinoline biodegradation, sorption and desorption in a clay-coated model soil containing a quinoline-degrading bacterium

    NASA Astrophysics Data System (ADS)

    McBride, J. F.; Brockman, F. J.; Szecsody, J. E.; Streile, G. P.

    1992-01-01

    Kinetics of quinoline biodegradation, sorption and desorption in a clay-coated model soil containing a quinoline-degrading bacterium. Studies were initiated to compare the kinetics of quinoline sorption/desorption and biodegradation in order to predict the relative importance of abiotic and biotic processes in the transport of quinoline in columns containing a model soil. Initial biodegradation studies were conducted in a 1-cm-long column containing a quinoline-degrading bacterium (10 9 colony-forming units g -1 porous medium) attached to 100- to 150-μm-diameter glass beads that did not sorb quinoline. At a 155-nmol mL -1 quinoline influent concentration, the maximum consumption rate was 104.7 nmol quinoline min -1 cm -3 pore volume. In contrast, the maximum consumption rate of the first metabolite ( 2-hydroxyquinoline) was 24.8 nmol mL -1 cm -3 pore volume. In a second experiment, bacteria were mixed with a model soil, consisting of montmorillonite bound to alumina particles (75- to 180-μm diameter). In a 1-cm-long column of the model soil, the quinoline consumption rate at a 155-nmol mL -1 quinoline influent concentration was similar to that obtained in the glass-bead column, showing that the clay does not substantially affect quinoline biodegradation at equilibrium conditions. In a third series of experiments, sorption to the model soil was examined in the absence of microorganisms. The observed desorption rate coefficient for quinoline averaged 1.1·10 -3 s -1, which was one to three orders of magnitude smaller than was observed for 45Ca. The slow ion exchange of quinoline on the clay surface is controlled by a site-specific quinoline/montmorillonite interaction and not a larger-scale physical step (i.e. interparticle diffusion). Equilibrium first-order forward (sorption) and reverse (desorption) mass fluxes were 1160 nmol cm -1 cm -3 pore volume with a 155-nmol mL -1 quinoline influent concentration. The initial quinoline mass flux to the clay was estimated

  10. Effects of ruminally degradable N in diets containing wet corn distiller's grains and steam-flaked corn on feedlot cattle performance and carcass characteristics

    USDA-ARS?s Scientific Manuscript database

    Assessment of degradable nitrogen (N) needs in diets containing wet corn distiller's grains with solubles (WCDGS) is needed to aid the cattle feeding industry in managing feed costs and potential environmental issues. Yearling steers (n = 525; initial weight = 822 +/- 28 lb) were housed in 56 pens (...

  11. Effects of ruminally degradable nitrogen in diets containing wet corn distiller's grains and steam-flaked corn on feedlot cattle performance and carcass characteristics

    USDA-ARS?s Scientific Manuscript database

    Assessment of degradable nitrogen (N) needs in diets containing wet corn distiller's grains with solubles (WCDGS) is needed to aid the cattle industry in managing feed costs. Yearling steers (n = 525; initial weight = 373 +/- 13 kg) were housed in 54 pens (9 to 10 steers/pen) and received treatments...

  12. Thiazolidinediones mimic glucose starvation in facilitating Sp1 degradation through the up-regulation of beta-transducin repeat-containing protein.

    PubMed

    Wei, Shuo; Chuang, Hsiao-Ching; Tsai, Wan-Chi; Yang, Hsiao-Ching; Ho, Shiuh-Rong; Paterson, Andrew J; Kulp, Samuel K; Chen, Ching-Shih

    2009-07-01

    This study investigated the mechanism by which the transcription factor Sp1 is degraded in prostate cancer cells. We recently developed a thiazolidinedione derivative, (Z)-5-(4-hydroxy-3-trifluoromethylbenzylidene)-3-(1-methylcyclohexyl)-thiazolidine-2,4-dione (OSU-CG12), that induces Sp1 degradation in a manner paralleling that of glucose starvation. Based on our finding that thiazolidinediones suppress beta-catenin and cyclin D1 by up-regulating the E3 ligase SCF(beta-TrCP), we hypothesized that beta-transducin repeat-containing protein (beta-TrCP) targets Sp1 for proteasomal degradation in response to glucose starvation or OSU-CG12. Here we show that either treatment of LNCaP cells increased specific binding of Sp1 with beta-TrCP. This direct binding was confirmed by in vitro pull-down analysis with bacterially expressed beta-TrCP. Although ectopic expression of beta-TrCP enhanced the ability of OSU-CG12 to facilitate Sp1 degradation, suppression of endogenous beta-TrCP function by a dominant-negative mutant or small interfering RNA-mediated knockdown blocked OSU-CG12-facilitated Sp1 ubiquitination and/or degradation. Sp1 contains a C-terminal conventional DSG destruction box ((727)DSGAGS(732)) that mediates beta-TrCP recognition and encompasses a glycogen synthase kinase 3beta (GSK3beta) phosphorylation motif (SXXXS). Pharmacological and molecular genetic approaches and mutational analyses indicate that extracellular signal-regulated kinase-mediated phosphorylation of Thr739 and GSK3beta-mediated phosphorylation of Ser728 and Ser732 were critical for Sp1 degradation. The ability of OSU-CG12 to mimic glucose starvation to activate beta-TrCP-mediated Sp1 degradation has translational potential to foster novel strategies for cancer therapy.

  13. Enhanced photocatalytic degradation of norfloxacin in aqueous Bi2WO6 dispersions containing nonionic surfactant under visible light irradiation.

    PubMed

    Tang, Lin; Wang, Jiajia; Zeng, Guangming; Liu, Yani; Deng, Yaocheng; Zhou, Yaoyu; Tang, Jing; Wang, Jingjing; Guo, Zhi

    2016-04-05

    Photocatalytic degradation is an alternative method to remove pharmaceutical compounds in water, however it is hard to achieve efficient rate because of the poor solubility of pharmaceutical compounds in water. This study investigated the photodegradation of norfloxacin in a nonionic surfactant Triton-X100 (TX100)/Bi2WO6 dispersion under visible light irradiation (400-750nm). It was found that the degradation of poorly soluble NOF can be strongly enhanced with the addition of TX100. TX100 was adsorbed strongly on Bi2WO6 surface and accelerated NOF photodegradation at the critical micelle concentration (CMC=0.25mM). Higher TX100 concentration (>0.25mM) lowered the degradation rate. In the presence of TX100, the degradation rate reached the maximum value when the pH value was 8.06. FTIR analyses demonstrated that the adsorbed NOF on the catalyst was completely degraded after 2h irradiation. According to the intermediates identified by HPLC/MS/MS, three possible degradation pathways were proposed to include addition of hydroxyl radical to quinolone ring, elimination of piperazynilic ring in fluoroquinolone molecules, and replacement of F atoms on the aromatic ring by hydroxyl radicals. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. A more accurate and penetrating method to measure the enrichment and mass of UF6 storage containers using passive neutron self-interrogation

    SciTech Connect

    Menlove, Howard O; Swinhoe, Martyn T; Miller, Karen A

    2010-01-01

    This paper describes an unattended mode neutron measurement that can provide the enrichment of the uranium in UF{sub 6} cylinders. The new passive neutron measurement provides better penetration into the uranium mass than prior gamma-ray enrichment measurement methods. The Passive Neutron Enrichment Monitor (PNEM) provides a new measurement technique that uses passive neutron totals and coincidence counting together with neutron self-interrogation to measure the enrichment in the cylinders. The measurement uses the neutron rates from two detector pods. One of the pods has a bare polyethylene surface next to the cylinder and the other polyethylene surface is covered with Cd to prevent thermal neutrons from returning to the cylinder. The primary neutron source from the enriched UF{sub 6} is the alpha-particle decay from the {sub 234}U that interacts with the fluorine to produce random neutrons. The singles neutron counting rate is dominated by the {sub 234}U neutrons with a minor contribution from the induced fissions in the {sub 235}U. However, the doubles counting rate comes primarily from the induced fissions (i.e., multiplication) in the {sub 235}U in enriched uranium. The PNEM concept makes use of the passive neutrons that are initially produced from the {sub 234}U reactions that track the {sub 235}U enrichment during the enrichment process. The induced fission reactions from the thermal-neutron albedo are all from the {sub 235}U and provide a measurement of the {sub 235}U. The Cd ratio has the desirable feature that all of the thermal-neutron-induced fissions in {sub 235}U are independent of the original neutron source. Thus, the ratio is independent of the uranium age, purity, and prior reactor history.

  15. A Novel Tricyclic Ligand-Containing Nonpeptidic HIV-1 Protease Inhibitor, GRL-0739, Effectively Inhibits the Replication of Multidrug-Resistant HIV-1 Variants and Has a Desirable Central Nervous System Penetration Property In Vitro

    PubMed Central

    Amano, Masayuki; Tojo, Yasushi; Salcedo-Gómez, Pedro Miguel; Parham, Garth L.; Nyalapatla, Prasanth R.; Das, Debananda; Ghosh, Arun K.

    2015-01-01

    We report here that GRL-0739, a novel nonpeptidic HIV-1 protease inhibitor containing a tricycle (cyclohexyl-bis-tetrahydrofuranylurethane [THF]) and a sulfonamide isostere, is highly active against laboratory HIV-1 strains and primary clinical isolates (50% effective concentration [EC50], 0.0019 to 0.0036 μM), with minimal cytotoxicity (50% cytotoxic concentration [CC50], 21.0 μM). GRL-0739 blocked the infectivity and replication of HIV-1NL4-3 variants selected by concentrations of up to 5 μM ritonavir or atazanavir (EC50, 0.035 to 0.058 μM). GRL-0739 was also highly active against multidrug-resistant clinical HIV-1 variants isolated from patients who no longer responded to existing antiviral regimens after long-term antiretroviral therapy, as well as against the HIV-2ROD variant. The development of resistance against GRL-0739 was substantially delayed compared to that of amprenavir (APV). The effects of the nonspecific binding of human serum proteins on the anti-HIV-1 activity of GRL-0739 were insignificant. In addition, GRL-0739 showed a desirable central nervous system (CNS) penetration property, as assessed using a novel in vitro blood-brain barrier model. Molecular modeling demonstrated that the tricyclic ring and methoxybenzene of GRL-0739 have a larger surface and make greater van der Waals contacts with protease than in the case of darunavir. The present data demonstrate that GRL-0739 has desirable features as a compound with good CNS-penetrating capability for treating patients infected with wild-type and/or multidrug-resistant HIV-1 variants and that the newly generated cyclohexyl-bis-THF moiety with methoxybenzene confers highly desirable anti-HIV-1 potency in the design of novel protease inhibitors with greater CNS penetration profiles. PMID:25691652

  16. Aggregation behavior of Triton X-100 with a mixture of two room-temperature ionic liquids: can we identify the mutual penetration of ionic liquids in ionic liquid containing micellar aggregates?

    PubMed

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

    2012-11-29

    In this manuscript, we have characterized two different micellar aggregates containing all nonvolatile components. We have shown (i) the effect of ethylammonium nitrate (EAN) addition on the properties of micellar solution of Triton X-100 in 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF(6)) and (ii) the effect of bmimPF(6) addition on the properties of micellar solution of Triton X-100 in EAN. To investigate the effect, we have used (1)H NMR, pulsed-field gradient spin-echo NMR (PFGSE NMR), and methyl orange (MO) and coumarin 153 (C-153) as absorption and emission probes, respectively. The penetration of added EAN inside the Triton X-100/bmimPF(6) micellar aggregates is indicated by (i) red shift in both the absorption spectra of MO and emission spectra of C-153 and (ii) downfield shift of proton signals of ethylene oxide units in Triton X-100. On the other hand, (1)H NMR and PFGSE NMR indicates the penetration of added bmimPF(6) inside the Triton X-100/EAN micellar aggregates. However, the constancy of both the absorption spectra of MO and emission spectra of C-153 indicates that the microenvironment around the probe molecules remains unaffected. We have also investigated the effect of micelle formation and the effect of penetration of ionic liquids (ILs) in micellar aggregates, on the solvation dynamics of C-153. The solvent relaxation around C-153 gets retarded on going from neat ILs to the micellar solution of Triton X-100 in ILs. In addition to this, we have also observed that with the addition of EAN in Triton X-100/bmimPF(6) micellar aggregates the solvation dynamics becomes faster, whereas with the addition of bmimPF(6) in Triton X-100/EAN micellar aggregates we did not observe any notable change in solvation dynamics. This observation further supports the conclusions drawn from UV-visible and NMR studies.

  17. The deep penetrating nevus.

    PubMed

    Strazzula, Lauren; Senna, Maryanne Makredes; Yasuda, Mariko; Belazarian, Leah

    2014-12-01

    The deep penetrating nevus (DPN), also known as the plexiform spindle cell nevus, is a pigmented lesion that commonly arises on the head and neck in the first few decades of life. Histopathologically, the DPN is wedge-shaped and contains melanocytes that exhibit deep infiltration into the dermis. Given these features, DPN may clinically and histopathologically mimic malignant melanoma, sparking confusion about the appropriate evaluation and management of these lesions. The goal of this review is to summarize the clinical and histopathological features of DPN and to discuss diagnostic and treatment strategies for dermatologists.

  18. Dietary starch source and protein degradability in diets containing sucrose: effects on ruminal measures and proposed mechanism for degradable protein effects.

    PubMed

    Hall, Mary Beth

    2013-01-01

    A feeding study was conducted to evaluate ruminal effects of starch source (STA) and rumen-degradable dietary protein (RDP) in diets with added sucrose. The experimental design was an incomplete Latin square with three 21-d periods, 8 ruminally cannulated lactating cows, and a 2 × 2 factorial arrangement of treatments. Treatments were STA (dry ground corn or high-moisture corn) as more slowly and more rapidly fermenting starch sources, respectively, and relative amount of RDP (+RDP: added protein from soybean meal; -RDP: heat-treated expeller soybean product partially substituted for soybean meal). Diets were formulated to be isonitrogenous and similar in starch and neutral detergent fiber concentrations. Dry matter (DM) intake was 1 kg greater with +RDP compared with -RDP diets. For ruminal digesta measures made 2 h postfeeding, weight of digesta DM was unaffected by treatment; total kilograms of wet digesta and kilograms of liquid tended to be greater with +RDP than with -RDP, and no effect was observed of STA × RDP. Digesta DM percentage was greater with -RDP than with +RDP. At 2 h postfeeding, ruminal pool sizes (mol) of lactate and total AA were larger and those of total organic acids (OA) and ammonia tended to be larger with +RDP than with -RDP; no effects of STA or STA × RDP were detected. Rumen-degradable protein effects on lactate and OA pool sizes may be due to a protein-mediated increase in fermentation rate of carbohydrate. Organic acid concentrations at 2 h postfeeding did not show the same response pattern or significance as the pool size data; high-moisture corn tended to be greater than dry ground corn and no effect was observed for RDP or STA × RDP. Concentration and pool size for OA were more weakly correlated [coefficient of determination (R(2)) = 0.66] than was the case for other ruminal analytes (R(2) >0.80). Organic acid pool size and kilograms of digesta liquid were strongly correlated (R(2) = 0.79), whereas concentration and kilograms of

  19. Dual-degradable disulfide-containing PEI-Pluronic/DNA polyplexes: transfection efficiency and balancing protection and DNA release.

    PubMed

    Zhang, Lifen; Chen, Zhenzhen; Li, Yanfeng

    2013-01-01

    Polymeric gene-delivery vectors to achieve lack of toxicity and a balance between protection and DNA release remains a formidable challenge. Incorporating intracellular environment-responsive degradable bonds is an appreciable step toward developing safer transfection agents. In this study, novel, dual-degradable polycation copolymers (Pluronic-diacrylate [PA]-polyethyleneimine [PEI]-SS) were synthesized through the addition of low molecular weight (800 Da) PEI cross-linked with SS (PEI-SS) to PA. Three PA-PEI-SS copolymers (PA-PEI-SS1, 2, and 3) with different PEI-SS to Pluronic molar ratios were investigated and found to strongly condense plasmid DNA into positively charged nanoparticles with an average particle size of approximately 200 nm and to possess higher stability against DNase I digestion and sodium heparin. Disulfide and ester bonds of the copolymers were susceptible to intracellular redox conditions. In vitro experiments demonstrated that the PA-PEI-SS copolymers had significantly lower cytotoxicity and higher transfection efficiency in both BGC-823 and 293T cell lines than the controls of degradable PEI-SS and nondegradable 25 kDa PEI. Transfection activity was influenced by the PEI-SS content in the polymers and PA-PEI-SS1 showed the highest efficiency of the three copolymers. These studies suggest that these dual-degradable copolymers could be used as potential biocompatible gene delivery carriers.

  20. Polycyclic aromatic hydrocarbon degradation by a Mycobacterium sp. in microcosms containing sediment and water from a pristine ecosystem

    SciTech Connect

    Heitkamp, M.A.; Cerniglia, C.E. )

    1989-08-01

    Microcosm studies were conducted to evaluate the survival and performance of a recently discovered polycyclic aromatic hydrocarbon (PAH)-degrading Mycobacterium sp. when this organism was added to sediment and water from a pristine ecosystem. Microcosms inoculated with the Mycobacterium sp. showed enhanced mineralization, singly and as components in a mixture, of 2-methylnaphthalene, phenanthrene, pyrene, and benzo(a)pyrene. Studies utilizing pyrene as the sole added PAH showed that the Mycobacterium sp. survived in microcosms for 6 weeks both with and without preexposure to PAH and mineralized multiple doses of pyrene. Pyrene mineralization rates for sterilized microcosms inoculated with the Mycobacterium sp. showed that competition with indigenous microorganisms did not adversely affect survival of or pyrene degradation by the Mycobacterium sp. Pyrene mineralization by the Mycobacterium sp. was not enhanced by inorganic nutrient enrichment and was hindered by organic nutrient enrichment, which appeared to result from overgrowth of indigenous bacteria. This study demonstrates the versatility of the PAH-degrading Mycobacterium sp. and expands its potential applications to include the degradation of two-, three-, four-, and five-ringed PAHs in sediments.

  1. Molybdenum-containing nicotine hydroxylase genes in a nicotine degradation pathway that is a variant of the pyridine and pyrrolidine pathways.

    PubMed

    Yu, Hao; Tang, Hongzhi; Li, Yangyang; Xu, Ping

    2015-12-01

    Ochrobactrum sp. strain SJY1 utilizes nicotine as a sole source of carbon, nitrogen, and energy via a variant of the pyridine and pyrrolidine pathways (the VPP pathway). Several strains and genes involved in the VPP pathway have recently been reported; however, the first catalyzing step for enzymatic turnover of nicotine is still unclear. In this study, a nicotine hydroxylase for the initial hydroxylation step of nicotine degradation was identified and characterized. The nicotine hydroxylase (VppA), which converts nicotine to 6-hydroxynicotine in the strain SJY1, is encoded by two open reading frames (vppAS and vppAL [subunits S and L, respectively]). The vppA genes were heterologously expressed in the non-nicotine-degrading strains Escherichia coli DH5α and Pseudomonas putida KT2440; only the Pseudomonas strain acquired the ability to degrade nicotine. The small subunit of VppA contained a [2Fe-2S] cluster-binding domain, and the large subunit of VppA contained a molybdenum cofactor-binding domain; however, an FAD-binding domain was not found in VppA. Resting cells cultivated in a molybdenum-deficient medium had low nicotine transformation activity, and excess molybdenum was detected in the purified VppA by inductively coupled plasma-mass spectrometry analysis. Thus, it is demonstrated that VppA is a two-component molybdenum-containing hydroxylase.

  2. Molybdenum-Containing Nicotine Hydroxylase Genes in a Nicotine Degradation Pathway That Is a Variant of the Pyridine and Pyrrolidine Pathways

    PubMed Central

    Yu, Hao; Li, Yangyang

    2015-01-01

    Ochrobactrum sp. strain SJY1 utilizes nicotine as a sole source of carbon, nitrogen, and energy via a variant of the pyridine and pyrrolidine pathways (the VPP pathway). Several strains and genes involved in the VPP pathway have recently been reported; however, the first catalyzing step for enzymatic turnover of nicotine is still unclear. In this study, a nicotine hydroxylase for the initial hydroxylation step of nicotine degradation was identified and characterized. The nicotine hydroxylase (VppA), which converts nicotine to 6-hydroxynicotine in the strain SJY1, is encoded by two open reading frames (vppAS and vppAL [subunits S and L, respectively]). The vppA genes were heterologously expressed in the non-nicotine-degrading strains Escherichia coli DH5α and Pseudomonas putida KT2440; only the Pseudomonas strain acquired the ability to degrade nicotine. The small subunit of VppA contained a [2Fe-2S] cluster-binding domain, and the large subunit of VppA contained a molybdenum cofactor-binding domain; however, an FAD-binding domain was not found in VppA. Resting cells cultivated in a molybdenum-deficient medium had low nicotine transformation activity, and excess molybdenum was detected in the purified VppA by inductively coupled plasma-mass spectrometry analysis. Thus, it is demonstrated that VppA is a two-component molybdenum-containing hydroxylase. PMID:26407884

  3. Overexpression and lack of degradation of thaumatin in an aspergillopepsin A-defective mutant of Aspergillus awamori containing an insertion in the pepA gene.

    PubMed

    Moralejo, F J; Cardoza, R E; Gutiérrez, S; Sisniega, H; Faus, I; Martín, J F

    2000-12-01

    A gene encoding the sweet-tasting protein thaumatin (tha) with optimized codon usage was expressed in Aspergillus awamori. Mutants of A. awamori with reduced proteolytic activity were isolated. One of these mutants, named lpr66, contained an insertion of about 200 bp in the pepA gene, resulting in an inactive aspergillopepsin A. In vitro thaumatin degradation tests confirmed that culture broths of mutant lpr66 showed only a small thaumatin-degrading activity. A. awamori lpr66 has been used as host strain for thaumatin expression cassettes containing the tha gene under the control of either the cahB (cephalosporin acetylhydrolase) promoter of Acremonium chrysogenum or the gdhA (glutamate dehydrogenase) promoter of Aspergillus awamori. Residual proteolytic activities were repressed by using a mixture of glucose and sucrose as carbon sources and L-asparagine as nitrogen source. Degradation of thaumatin by acidic proteases was prevented by maintaining the pH value at 6.2 in the fermentor. Expression of cassettes containing the gdhA promoter was optimal in ammonium sulfate as nitrogen source, whereas transformants expressing the tha gene from the cahB promoter yielded higher thaumatin levels using L-asparagine as nitrogen source. Under optimal fermentation conditions, yields of 105 mg thaumatin/l were obtained, thus making this fermentation a process of industrial interest.

  4. Degradative properties and cytocompatibility of a mixed-mode hydrogel containing oligo[poly(ethylene glycol)fumarate] and poly(ethylene glycol)dithiol.

    PubMed

    Brink, Kelly S; Yang, Peter J; Temenoff, Johnna S

    2009-02-01

    Our laboratory is currently exploring synthetic oligo(poly(ethylene glycol)fumarate) (OPF)-based biomaterials as a means to deliver fibroblasts to promote regeneration of central/partial defects in tendons and ligaments. In order to further modulate the swelling and degradative characteristics of OPF-based hydrogels, OPF crosslinking via a radically initiated, mixed-mode reaction involving poly(ethylene glycol) (PEG)-diacrylate and PEG-dithiol was investigated. Results demonstrate that mixed-mode hydrogels containing OPF can be formed and that the presence of 20 wt.% PEG-dithiol increases swelling and decreases degradation time vs. 10 wt.% PEG-dithiol and non-thiol-containing hydrogels (20% thiol fold swelling 28.7+/-0.8; 10% thiol fold swelling 11.6+/-1.4; non-thiol 8.7+/-0.2; 20% thiol-containing hydrogels degrade within 15 days in vitro). After encapsulation, tendon/ligament fibroblasts remained largely viable over 8 days of static culture. While the presence of PEG-dithiol did not significantly affect cellularity or collagen production within the constructs over this time period, image analysis revealed that the 20% PEG-dithiol gels did appear to promote cell clustering, with greater values for aggregate area observed by day 8. These experiments suggest that mixed-mode OPF-based hydrogels may provide an interesting alternative as a cell carrier for engineering a variety of soft orthopedic tissues, particularly for applications when it is important to encourage cell-cell contact.

  5. Genome-resolved metagenomics of a bioremediation system for degradation of thiocyanate in mine water containing suspended solid tailings.

    PubMed

    Rahman, Sumayah F; Kantor, Rose S; Huddy, Robert; Thomas, Brian C; van Zyl, Andries W; Harrison, Susan T L; Banfield, Jillian F

    2017-06-01

    Thiocyanate (SCN(-) ) is a toxic compound that forms when cyanide (CN(-) ), used to recover gold, reacts with sulfur species. SCN(-) -degrading microbial communities have been studied, using bioreactors fed synthetic wastewater. The inclusion of suspended solids in the form of mineral tailings, during the development of the acclimatized microbial consortium, led to the selection of an active planktonic microbial community. Preliminary analysis of the community composition revealed reduced microbial diversity relative to the laboratory-based reactors operated without suspended solids. Despite minor upsets during the acclimation period, the SCN(-) degradation performance was largely unchanged under stable operating conditions. Here, we characterized the microbial community in the SCN(-) degrading bioreactor that included solid particulate tailings and determined how it differed from the biofilm-based communities in solids-free reactor systems inoculated from the same source. Genome-based analysis revealed that the presence of solids decreased microbial diversity, selected for different strains, suppressed growth of thiobacilli inferred to be primarily responsible for SCN(-) degradation, and promoted growth of Trupera, an organism not detected in the reactors without solids. In the solids reactor community, heterotrophy and aerobic respiration represent the dominant metabolisms. Many organisms have genes for denitrification and sulfur oxidation, but only one Thiobacillus sp. in the solids reactor has SCN(-) degradation genes. The presence of the solids prevented floc and biofilm formation, leading to the observed reduced microbial diversity. Collectively the presence of the solids and lack of biofilm community may result in a process with reduced resilience to process perturbations, including fluctuations in the influent composition and pH. The results from this investigation have provided novel insights into the community composition of this industrially relevant

  6. The effect of various antioxidants on the degradation of O/W microemulsions containing esterified astaxanthins from Haematococcus pluvialis.

    PubMed

    Zhou, Qingxin; Xu, Jie; Yang, Shu; Xue, Yong; Zhang, Ting; Wang, Jingfeng; Xue, Changhu

    2015-01-01

    Esterified astaxanthins are used as functional nutraceuticals and pigments in many food products. Unfortunately, the utilization is currently limited due to their chemical instability and poor water-solubility. In this study, esterified astaxanthins were quantified and purified from Haematococcus pluvialis using a novel and precise approach. By HPLC-(+)APCI-MS/MS, twenty esterified astaxanthin molecular species were identified, of which classified into eight monoester forms (approximately 85%, w/w) and twelve diester forms (approximately 15%, w/w), depending on the number of fatty acids that bind thereto. The MS data showed that the predominant fatty acids in astaxanthin esters of H. pluvialis are usually a long chain fatty acid with 16~18 carbon atoms, such as C18:1, C18:2, C18:3, C18:4, C16:0, C16:1. The purity of the esterified astaxanthins was determined to be 96.8±1.2% after purification. A well water-dispersible microemulsion was fabricated using high purity esterified astaxanthins, ethyl butyrate, Tween 80 and ethanol; and that emulsion exhibited a mean particle radius around 60 nm. The chemical degradation of esterified astaxanthins was monitored under accelerated stress storage conditions. After storage for 20 days, the results indicated that the degradation of esterified astaxanthins was effectively slowed by the addition of antioxidants to the microemulsions. By investigating the dependence of the chemical degradation of the esterified astaxanthins in O/W microemulsions on the concentration of the additives, it was concluded that the effectiveness of the additives at inhibiting the degradation of the esterified astaxanthins decreased in the following order: EDTA > ascorbic acid > vitamin E acetate. The utilization of antioxidants in combination was less effective than using them individually. These results provide information for designing effective delivery systems, thereby delaying the chemical degradation of esterified astaxanthins in foods

  7. Monolithic ballasted penetrator

    DOEpatents

    Hickerson, Jr., James P.; Zanner, Frank J.; Baldwin, Michael D.; Maguire, Michael C.

    2001-01-01

    The present invention is a monolithic ballasted penetrator capable of delivering a working payload to a hardened target, such as reinforced concrete. The invention includes a ballast made from a dense heavy material insert and a monolithic case extending along an axis and consisting of a high-strength steel alloy. The case includes a nose end containing a hollow portion in which the ballast is nearly completely surrounded so that no movement of the ballast relative to the case is possible during impact with a hard target. The case is cast around the ballast, joining the two parts together. The ballast may contain concentric grooves or protrusions that improve joint strength between the case and ballast. The case further includes a second hollow portion; between the ballast and base, which has a payload fastened within this portion. The penetrator can be used to carry instrumentation to measure the geologic character of the earth, or properties of arctic ice, as they pass through it.

  8. Preparation and characterization of bioactive and degradable composites containing ordered mesoporous calcium-magnesium silicate and poly(L-lactide)

    NASA Astrophysics Data System (ADS)

    Ji, Jiajin; Dong, Xieping; Ma, Xuhui; Tang, Songchao; Wu, Zhaoying; Xia, Ji; Wang, Quanxiang; Wang, Yutao; Wei, Jie

    2014-10-01

    Polylactide (PLA) and its copolymers have been widely used for bone tissue regeneration. In this study, a bioactive composite of ordered mesoporous calcium-magnesium silicate (m-CMS) and poly(L-lactide) (PLLA) was fabricated by melt blending method. The results indicated that the m-CMS particles were entrapped by polymer phase, and crystallinity of PLLA significantly decreased while the thermal stability of the m-CMS/PLLA composites was not obviously affected by addition of the m-CMS into PLLA. In addition, compared to PLLA, incorporation of the m-CMS into PLLA significantly improved the hydrophilicity, in vitro degradability and bioactivity (apatite-formation ability) of the m-CMS/PLLA composite, which were m-CMS content dependent. Moreover, it was found that incorporation of the m-CMS into PLLA could neutralize the acidic degradation by-products and thus compensated for the decrease of pH value. In cell culture experiments, the results showed that the composite enhanced attachment, proliferation and alkaline phosphatase activity (ALP) of MC3T3-E1 cells, which were m-CMS content dependent. The results indicated that the addition of bioactive materials to PLLA could result in a composite with improved properties of hydrophilicity, degradability, bioactivity and cytocompatibility.

  9. Evaluation of cellobiose dehydrogenase and laccase containing culture fluids of Termitomyces sp. OE147 for degradation of Reactive blue 21.

    PubMed

    Gangwar, Rishabh; Rasool, Shafaq; Mishra, Saroj

    2016-12-01

    This study evaluates culture filtrate, rich in cellobiose dehydrogenase and laccases, of Termitomyces sp. OE 147, in decolouration and degradation of Reactive blue (RB) 21. About 35% decolouration was achieved at low volumes of the culture supernatant without addition of external redox mediators. An optimized dye to culture fluid ratio (75 ppm: 0.1 ml) at a pH of 4-5 resulted in removal of colour by 60%. The degradation products of RB21 were analysed by Electron Spray Ionization-Mass Spectrometry and several small molecules (of m/z 106-199) were detected. These were concluded to be o-Xylene, 2,3-Dihydro-1H-isoindole, Isoindole-1,3-dione, 2,Benzenesulfonyl-ethanol, (4-Hydroxy-phenyl)-sulfamic acid, 2,3-Dihydro-1H-isoindole-5-sulfonic acid and proposed to result from joint action of cellobiose dehydrogenase, laccase, peroxidases and unidentified oxidoreductases present in the culture fluids. Based on the products formed and the known reactions of these enzymes, a degradation pathway was proposed for RB21. The culture fluid was also effective in decolouration (by about 50%) and detoxification (by ∼25%) of the combined effluent collected from a local mill indicating a treatment process that bypasses use of H2O2 and toxic mediators.

  10. The opposite role of two UBA-UBX containing proteins, p47 and SAKS1 in the degradation of a single ERAD substrate, α-TCR.

    PubMed

    Park, Eun Sil; Yoo, Yung Joon; Elangovan, Muthukumar

    2017-01-01

    The UBA-UBX domain-containing proteins can interact with ubiquitinated substrates and p97 during endoplasmic reticulum-associated degradation (ERAD). Here, we found that the expressions of all UBA-UBX genes p47, SAKS1, UBXD8, FAF1, and UBXD7 were elevated upon ER stress, albeit with different levels. Of which p47, SAKS1, and UBXD8 are 'immediate' respondents whereas FAF1 and UBXD7 were 'late' respondents to ER stress. Interestingly, the expression of specific UBA-UBX genes were altered in cells stably expressing three different ERAD substrates such as α-TCR, α1-antitrypsin, and δCD3. We first found that p47 and UBXD8 expression levels were increased in α-TCR and α1-antitrypsin stable cell lines, respectively, whereas SAKS1 expression level was reduced in all the three ERAD substrates tested. Of note, we also found p47 promotes, whereas SASK1 delays the degradation of a single ERAD substrate, α-TCR. Additionally, we found that SAKS1 selectively inhibits the degradation of ERAD substrates without affecting cytosolic proteasomal substrates. Taken together, our results identified that UBA-UBX proteins possess substrate selectivity and opposite role of two different UBA-UBX proteins in the degradation of a single ERAD substrate.

  11. THE PENETRATION OF STRONG ELECTROLYTES

    PubMed Central

    Cooper, W. C.; Dorcas, M. J.; Osterhout, W. J. V.

    1929-01-01

    The entrance of strong electrolytes into Valonia is very slow unless the cells are injured. This, together with the very high electrical resistance of the protoplasm, suggests that they may penetrate largely as undissociated molecules formed at the surface of the protoplasm by the collision of ions. Under favorable circumstances KCl may be absorbed to the extent of 3 x 10–8 mols per hour per sq. cm. of surface together with about 0.17 as much NaCl. Other substances which seem to penetrate to some extent are Li, Rb, Br, BrO3, I, IO3, and selenite. Little or no penetration is shown by SCN, ferricyanide, ferrocyanide, formate, salicylate, tungstate, seleniate, NO2, SO3, Sb, glycerophosphate, and many heavy metals and the alkaline earths. In sea water whose specific gravity had been increased by CsCl cells of Valonia floated for over a year and there was little or no penetration of Cs except as the result of injury. The penetration of NH4Cl decreases the specific gravity of the sap and causes the cells to float: under these circumstances they live indefinitely. It is probable that NH3 or NH4OH penetrates and is subsequently changed to NH4Cl. It would seem that if the sea contained a little more ammonia this would be a floating organism. PMID:19872471

  12. Alginate beads as a storage, delivery and containment system for genetically modified PCB degrader and PCB biosensor derivatives of Pseudomonas fluorescens F113.

    PubMed

    Power, B; Liu, X; Germaine, K J; Ryan, D; Brazil, D; Dowling, D N

    2011-05-01

    Pseudomonas fluorescens F113Rifpcb is a genetically engineered rhizosphere bacterium with the potential to degrade polychlorinated biphenyls (PCBs). F113Rifpcbgfp and F113L::1180gfp are biosensor strains capable of detecting PCB bioavailability and biodegradation. The aim of this paper is to evaluate the use of alginate beads as a storage, delivery and containment system for use of these strains in PCB contaminated soils. The survival and release of Ps. fluorescens F113Rifpcb from alginate beads were evaluated. Two Ps. fluorescens F113-based biosensor strains were encapsulated, and their ability to detect 3-chlorobenzoate (3-CBA) and 3-chlorobiphenyl (3-CBP) degradation in soil was assessed. After 250 days of storage, 100% recovery of viable F113Rifpcb cells was possible. Amendments to the alginate formulation allowed for the timed release of the inoculant. Encapsulation of the F113Rifpcb cells provided a more targeted approach for the inoculation of plants and resulted in lower inoculum populations in the bulk soil, which may reduce the risk of unintentional spread of these genetically modified micro-organisms in the environment. Encapsulation of the biosensor strains in alginate beads did not interfere with their ability to detect either 3-CBA or 3-CBP degradation. In fact, detection of 3-CBP degradation was enhanced in encapsulated biosensors.   Alginate beads are an effective storage and delivery system for PCB degrading inocula and biosensors. Pseudomonas fluorescens F113Rifpcb and the F113 derivative PCB biosensor strains have excellent potential for detecting and bioremediation of PCB contaminated soils. The alginate bead delivery system could facilitate the application of these strains as biosensors. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  13. Microbial removal of organic sulfur from coal (bacterial degradation of sulfur-containing heterocyclic compounds): Final report, March 1--December 31, 1987

    SciTech Connect

    Klubek, B.; Clark, D.

    1988-03-01

    The presence of levels of sulfur in coal is a major source of air pollution and considerable efforts are being made to devise a cost-effective way of removing it. One promising method is microbial desulfurization. Almost all of the inorganic sulfur can be removed from coal by the bacteria Thiobacillus or Sulfolobus, which convert sulfide to sulfate but leave the organic sulfur untouched. If strains of bacteria are developed which remove organic sulfur from coal and are used in conjunction with inorganic sulfur-oxidizing bacteria, the result should be an effective desulfurization method. We are using two approaches to develop bacteria which remove organic sulfur. One method is to mutate a laboratory species, Escherichia coli, an organism which is genetically well understood and whose pathways for the metabolism of sulfur-containing amino acids have been extensively investigated. Such thiophene degraders can be genetically analyzed, and the genes involved can be cloned in order to amplify their products. The second approach is the development of naturally occurring bacteria capable of thiophene degradation. Enrichment culture techniques, mutagenesis of current isolated strains, and mixed culture studies with crushed coal comprise an alternative approach in our study. The degradation rates of our model-thiophene compounds and the preliminary testing of our isolates with coal will index the efficiency of our strains in coal desulfurization. Ultimately, the genes responsible for thiophene degradation by our isolated strains will be transferred to our E. coli strain, creating a single organism capable of degrading a broad spectrum of thiophene compounds. 14 refs., 5 tabs.

  14. Performance degradation of double-perovskite PrBaCo2O5+δ oxygen electrode in CO2 containing atmospheres

    NASA Astrophysics Data System (ADS)

    Zhu, Lin; Wei, Bo; Lü, Zhe; Feng, Jiebing; Xu, Lingling; Gao, Hong; Zhang, Yaohui; Huang, Xiqiang

    2017-09-01

    The electrochemical performance and microstructure stability of PrBaCo2O5+δ (PBCO) cathode are investigated in CO2-containing atmospheres for solid oxide fuel cells (SOFCs). Electrochemical impedance spectra results confirm obvious performance degradation of the PBCO cathodes in the presence of CO2 impurity, especially in high CO2 concentration condition. Microstructure and structural analyses reveal the formation of insulating BaCO3 nanoparticles at the PBCO surface, which is considered as the primary reason for the loss of electrode activity. This study highlights the important role of surface segregated BaO species in determining the activity and long-time stability of PBCO electrode.

  15. Penetration of concrete targets

    SciTech Connect

    Forrestal, M.J.; Cargile, J.D.; Tzou, R.D.Y.

    1993-08-01

    We developed penetration equations for ogive-nosed projectiles that penetrated concrete targets after normal impact. Our penetration equations predict axial force on the projectile nose, rigid-body motion, and final penetration depth. For target constitutive models, we conducted triaxial material experiments to confining pressures of 600 MPa and curve-fit these data with a linear pressure-volumetric strain relation and with a linear Mohr-Coulomb, shear strength-pressure relation. To verify our penetration equations, we conducted eleven penetration experiments with 0.90 kg, 26.9-mm-diameter, ogive-nosed projectiles into 1.37-m-diameter concrete targets with unconfined compressive strengths between 32-40 MPa. Predictions from our penetration equation are compared with final penetration depth measurements for striking velocities between 280--800 m/s.

  16. Fucose-containing fraction of Ling-Zhi enhances lipid rafts-dependent ubiquitination of TGFβ receptor degradation and attenuates breast cancer tumorigenesis

    PubMed Central

    Tsao, Shu-Ming; Hsu, Hsien-Yeh

    2016-01-01

    Ganoderma lucidum exerts antitumor activity, but the mechanism of G. lucidum polysaccharides on cancer is unclear. Here, we demonstrated that a fucose-containing fraction of Ling-Zhi (FFLZ) reduced tumor size and suppressed metastasis in vivo. Furthermore, FFLZ inhibited breast cancer cell migration and altered the epithelial-to-mesenchymal transition (EMT) phenotype. Transforming growth factor-β receptor (TGFR) pathways act as key mediators to promote tumor progression and metastasis. We found that FFLZ down-regulated TGFR and downstream signaling pathways, including the phosphorylation of Smad2/3 and the expression of Smad4. In an investigation of the underlying mechanisms, we found that FFLZ enhanced the Smurf2-dependent ubiquitination of TGFR by disrupting the balance of the lipid rafts, promoted the “re-localization” of the TGFR to the caveolae, and facilitated the degradation of TGFR. Together, our data indicated that FFLZ is associated with the inhibition of EMT and the prevention of metastasis by promoting ubiquitination-dependent TGFR degradation and abolishing TGFR signaling pathways. Moreover, the combination of FFLZ and trastuzumab synergistically inhibited the viability of certain trastuzumab-resistant human breast cancer cells. In summary, our current findings indicate that FFLZ is a potential therapeutic or dietary supplemental agent for cancer patients and that it functions via the caveolin-1/Smad7/Smurf2-dependent ubiquitin-mediated degradation of TGFR. PMID:27830743

  17. Lunar regolith penetrators and cutters

    NASA Technical Reports Server (NTRS)

    Barnes, Frank; Sture, Stein

    1991-01-01

    An apparatus was designed and built for conducting simulation experiments on cutting tool penetration in the centrifuge. This equipment is mounted on the laminar container which is used for the regolith densification study, so that the end product of the latter, i.e., a regolith bed with the proper density profile, can be used directly for the penetration tests. In this apparatus, an etching tool is suspended through a pulley system by the action of a double acting air cylinder. By adjusting the air pressure acting on each side of the cylinder, the net downward force acting on the tool can be controlled. The penetration of the tool is measured by an LVDT. This apparatus was proof-tested in the centrifuge and is ready for use in conjunction with the regolith densification experiments.

  18. Degradation Pathway of Bisphenol A: Does ipso Substitution Apply to Phenols Containing a Quaternary α-Carbon Structure in the para Position?▿ †

    PubMed Central

    Kolvenbach, B.; Schlaich, N.; Raoui, Z.; Prell, J.; Zühlke, S.; Schäffer, A.; Guengerich, F. P.; Corvini, P. F. X.

    2007-01-01

    The degradation of bisphenol A and nonylphenol involves the unusual rearrangement of stable carbon-carbon bonds. Some nonylphenol isomers and bisphenol A possess a quaternary α-carbon atom as a common structural feature. The degradation of nonylphenol in Sphingomonas sp. strain TTNP3 occurs via a type II ipso substitution with the presence of a quaternary α-carbon as a prerequisite. We report here a new degradation pathway of bisphenol A. Consequent to the hydroxylation at position C-4, according to a type II ipso substitution mechanism, the C-C bond between the phenolic moiety and the isopropyl group of bisphenol A is broken. Besides the formation of hydroquinone and 4-(2-hydroxypropan-2-yl)phenol as the main metabolites, further compounds resulting from molecular rearrangements consistent with a carbocationic intermediate were identified. Assays with resting cells or cell extracts of Sphingomonas sp. strain TTNP3 under an 18O2 atmosphere were performed. One atom of 18O2 was present in hydroquinone, resulting from the monooxygenation of bisphenol A and nonylphenol. The monooxygenase activity was dependent on both NADPH and flavin adenine dinucleotide. Various cytochrome P450 inhibitors had identical inhibition effects on the conversion of both xenobiotics. Using a mutant of Sphingomonas sp. strain TTNP3, which is defective for growth on nonylphenol, we demonstrated that the reaction is catalyzed by the same enzymatic system. In conclusion, the degradation of bisphenol A and nonylphenol is initiated by the same monooxygenase, which may also lead to ipso substitution in other xenobiotics containing phenol with a quaternary α-carbon. PMID:17557840

  19. Investigation of the mechanism of enhanced skin penetration by ultradeformable liposomes

    PubMed Central

    Subongkot, Thirapit; Pamornpathomkul, Boonnada; Rojanarata, Theerasak; Opanasopit, Praneet; Ngawhirunpat, Tanasait

    2014-01-01

    This study aimed to determine the mechanism by which ultradeformable liposomes (ULs) with terpenes enhance skin penetration for transdermal drug delivery of fluorescein sodium, using transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Skin treated with ULs containing d-limonene, obtained from in vitro skin penetration studies, was examined via TEM to investigate the effect of ULs on ultrastructural changes of the skin, and to evaluate the mechanism by which ULs enhance skin penetration. The receiver medium collected was analyzed by TEM and CLSM to evaluate the mechanism of the drug carrier system. Our findings revealed that ULs could enhance penetration by denaturing intracellular keratin, degrading corneodesmosomes, and disrupting the intercellular lipid arrangement in the stratum corneum. As inferred from the presence of intact vesicles in the receiver medium, ULs are also able to act as a drug carrier system. CLSM images showed that intact vesicles of ULs might penetrate the skin via a transappendageal pathway, potentially a major route of skin penetration. PMID:25114524

  20. Triesterase and promiscuous diesterase activities of a di-Co(II)-containing organophosphate degrading enzyme reaction mechanisms.

    PubMed

    Alberto, Marta E; Pinto, Gaspar; Russo, Nino; Toscano, Marirosa

    2015-02-23

    The reaction mechanism for the hydrolysis of trimethyl phosphate and of the obtained phosphodiester by the di-Co(II) derivative of organophosphate degrading enzyme from Agrobacterium radiobacter P230(OpdA), have been investigated at density functional level of theory in the framework of the cluster model approach. Both mechanisms proceed by a multistep sequence and each catalytic cycle begins with the nucleophilic attack by a metal-bound hydroxide on the phosphorus atom of the substrate, leading to the cleavage of the phosphate-ester bond. Four exchange-correlation functionals were used to derive the potential energy profiles in protein environments. Although the enzyme is confirmed to work better as triesterase, as revealed by the barrier heights in the rate-limiting steps of the catalytic processes, its promiscuous ability to hydrolyze also the product of the reaction has been confirmed. The important role played by water molecules and some residues in the outer coordination sphere has been elucidated, while the binuclear Co(II) center accomplishes both structural and catalytic functions. To correctly describe the electronic configuration of the d shell of the metal ions, high- and low-spin arrangement jointly with the occurrence of antiferromagnetic coupling, have been herein considered.

  1. The role of the cyclic imide in alternate degradation pathways for asparagine-containing peptides and proteins.

    PubMed

    Dehart, Michael P; Anderson, Bradley D

    2007-10-01

    Peptides and proteins exhibit enhanced reactivity at asparagine residues due to the formation of a reactive succinimide intermediate that produces normal and isoaspartyl deamidation products along with significant racemization. This study examines the potential for attack of amine nucleophiles at the succinimide carbonyls to generate alternate decomposition products, depending on the nucleophile involved in the reaction. The reactions of the model peptides Phe-Asn-Gly (FNG) and Phe-isoAsn-Gly (FisoNG) were explored as a function of pH (8.5-10.5) in the presence and absence of ammonia buffer (0.2-2 M) using an isocratic HPLC method to monitor reactant disappearance and product formation. In addition to deamidation to form isoAsp and Asp peptides, two additional types of reactions were found to occur via the succinimide intermediate under these conditions. Back-reaction of the succinimide with ammonia led to peptide backbone isomerization while intramolecular attack by the amino terminus produced diketopiperazines. A kinetic model assuming a central role for the succinimide intermediate was derived to fit the concentration versus time data. These studies implicate the cyclic imide as a key intermediate in the formation of alternate peptide and protein degradants, including possible covalent amide-linked aggregates that may form from intermolecular attack of the cyclic imide by neighboring amino groups. (c) 2007 Wiley-Liss, Inc.

  2. Photocatalytic property of a keggin-type polyoxometalates-containing bilayer system for degradation organic dye model.

    PubMed

    Li, Taohai; Gao, Shuiying; Li, Feng; Cao, Rong

    2009-10-15

    The photocatalytic activity composite films incorporating the Keggin-type polyoxometalates (POM) K6CoW12O40.-16H2O and K3PW12O40.-nH2O (MW12 (M=P, Co)) and [Cu(II)(1,8-dimethyl-1, 3, 6, 8, 10, 13-hexaazacycloteradecane)](2+)(L) have been prepared by the layer-by-layer (LbL) self-assembly method. The experimental results show that the deposition process is linear and highly reproducible from layer to layer. Atomic force microscopy (AFM) images of the L/MW12 composite films indicate that the film surface is relatively uniform and smooth. In addition, the films show high photocatalytic activity to the degradation of organic dye model (methyl orange (MO)), attributed to the formation of an O-->W charge-transfer excited state at W-O-W bridge bond, resulting in generating highly reactive holes and electrons; The photocatalytic efficiency of the films have little change after several times of photocatalytic cycle, indicating that the composite films are stable, reused and recovered.

  3. Microbial characterization and degradation of linear alkylbenzene sulfonate in an anaerobic reactor treating wastewater containing soap powder.

    PubMed

    Carosia, Mariana Fronja; Okada, Dagoberto Yukio; Sakamoto, Isabel Kimiko; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2014-09-01

    The aim of this study was to evaluate the removal of linear alkylbenzene sulfonate (LAS) in an anaerobic fluidized bed reactor (AFBR) treating wastewater containing soap powder as LAS source. At Stage I, the AFBR was fed with a synthetic substrate containing yeast extract and ethanol as carbon sources, and without LAS; at Stage II, soap powder was added to this synthetic substrate obtaining an LAS concentration of 14 ± 3 mg L(-1). The compounds of soap powder probably inhibited some groups of microorganisms, increasing the concentration of volatile fatty acids (VFA) from 91 to 143 mg HAc L(-1). Consequently, the LAS removal rate was 48 ± 10% after the 156 days of operation. By sequencing, 16S rRNA clones belonging to the phyla Proteobacteria and Synergistetes were identified in the samples taken at the end of the experiment, with a remarkable presence of Dechloromonas sp. and Geobacter sp. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The autophagic degradation of chloroplasts via rubisco-containing bodies is specifically linked to leaf carbon status but not nitrogen status in Arabidopsis.

    PubMed

    Izumi, Masanori; Wada, Shinya; Makino, Amane; Ishida, Hiroyuki

    2010-11-01

    Autophagy is an intracellular process facilitating the vacuolar degradation of cytoplasmic components and is important for nutrient recycling during starvation. We previously demonstrated that chloroplasts can be partially mobilized to the vacuole by autophagy via spherical bodies named Rubisco-containing bodies (RCBs). Although chloroplasts contain approximately 80% of total leaf nitrogen and represent a major carbon and nitrogen source for new growth, the relationship between leaf nutrient status and RCB production remains unclear. We examined the effects of nutrient factors on the appearance of RCBs in leaves of transgenic Arabidopsis (Arabidopsis thaliana) expressing stroma-targeted fluorescent proteins. In excised leaves, the appearance of RCBs was suppressed by the presence of metabolic sugars, which were added externally or were produced during photosynthesis in the light. The light-mediated suppression was relieved by the inhibition of photosynthesis. During a diurnal cycle, RCB production was suppressed in leaves excised at the end of the day with high starch content. Starchless mutants phosphoglucomutase and ADP-Glc pyrophosphorylase1 produced a large number of RCBs, while starch-excess mutants starch-excess1 and maltose-excess1 produced fewer RCBs. In nitrogen-limited plants, as leaf carbohydrates were accumulated, RCB production was suppressed. We propose that there exists a close relationship between the degradation of chloroplast proteins via RCBs and leaf carbon but not nitrogen status in autophagy. We also found that the appearance of non-RCB-type autophagic bodies was not suppressed in the light and somewhat responded to nitrogen in excised leaves, unlike RCBs. These results imply that the degradation of chloroplast proteins via RCBs is specifically controlled in autophagy.

  5. FAA fluorescent penetrant activities

    SciTech Connect

    Moore, D.G.; Larson, B.F.

    1997-11-01

    The Federal Aviation Administration`s Airworthiness Assurance NDI Validation Center (AANC) and the Center for Aviation Systems Reliability (CASR) are currently working to develop a liquid penetrant inspection (LPI) system evaluation capability that will support the needs of the penetrant manufacturers, commercial airline industry and the FAA. The main focus of this facility is to support the evaluation of penetrant inspection materials, penetrant systems and to apply resources to support industry needs. This paper discusses efforts to create such a facility and an initial project to produce fatigue crack specimens for evaluation of Type 1 penetrant sensitivities.

  6. Uracil DNA glycosylase initiates degradation of HIV-1 cDNA containing misincorporated dUTP and prevents viral integration

    PubMed Central

    Weil, Amy F.; Ghosh, Devlina; Zhou, Yan; Seiple, Lauren; McMahon, Moira A.; Spivak, Adam M.; Siliciano, Robert F.; Stivers, James T.

    2013-01-01

    HIV-1 reverse transcriptase discriminates poorly between dUTP and dTTP, and accordingly, viral DNA products become heavily uracilated when viruses infect host cells that contain high ratios of dUTP:dTTP. Uracilation of invading retroviral DNA is thought to be an innate immunity barrier to retroviral infection, but the mechanistic features of this immune pathway and the cellular fate of uracilated retroviral DNA products is not known. Here we developed a model system in which the cellular dUTP:dTTP ratio can be pharmacologically increased to favor dUTP incorporation, allowing dissection of this innate immunity pathway. When the virus-infected cells contained elevated dUTP levels, reverse transcription was found to proceed unperturbed, but integration and viral protein expression were largely blocked. Furthermore, successfully integrated proviruses lacked detectable uracil, suggesting that only nonuracilated viral DNA products were integration competent. Integration of the uracilated proviruses was restored using an isogenic cell line that had no detectable human uracil DNA glycosylase (hUNG2) activity, establishing that hUNG2 is a host restriction factor in cells that contain high dUTP. Biochemical studies in primary cells established that this immune pathway is not operative in CD4+ T cells, because these cells have high dUTPase activity (low dUTP), and only modest levels of hUNG activity. Although monocyte-derived macrophages have high dUTP levels, these cells have low hUNG activity, which may diminish the effectiveness of this restriction pathway. These findings establish the essential elements of this pathway and reconcile diverse observations in the literature. PMID:23341616

  7. Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers

    SciTech Connect

    Bedrossian, P; Estill, J; Farmer, J; Hopper, R; Horn, J; Huang, J S; McCright, D; Roy, A; Wang, F; Wilfinger, K

    1999-02-08

    A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 825, 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as A516 Gr 55, a carbon steel, or Monel 400. At the present time, Alloy C-22 and A516 G4 55 are favored.

  8. Development of integraded mechanistically-based degradation-mode models for performance assessment of high-level waste containers

    SciTech Connect

    Farmer, J. C., LLNL

    1998-06-01

    A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-tayer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 825, 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as A516 Gr 55 or Monel 400. At the present time, Alloy C- 22 and A516 Gr 55 are favored.

  9. Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers

    SciTech Connect

    Farmer, J C; McCright, R D; Estill, J C; Gordon, S R

    1998-11-02

    Alloy 22 [UNS NO60221] is now being considered for construction of high level waste containers to be emplaced at Yucca Mountain and elsewhere. In essence, this alloy is 21% Cr, 13% MO, 4% Fe, 3% W, 2% Co, with the balance being Ni. Variants without tungsten are also being considered. Detailed mechanistic models have been developed to account for the corrosion of Alloy 22 surfaces in crevices that will inevitably form. Such occluded areas experience substantial decreases in pH, with corresponding elevations in chloride concentration. Experimental work has been undertaken to validate the crevice corrosion model, including parallel studies with 304 stainless steel.

  10. Degradability, bioactivity, and osteogenesis of biocomposite scaffolds of lithium-containing mesoporous bioglass and mPEG-PLGA-b-PLL copolymer.

    PubMed

    Cai, Yanrong; Guo, Lieping; Shen, Hongxing; An, Xiaofei; Jiang, Hong; Ji, Fang; Niu, Yunfei

    2015-01-01

    Biocomposite scaffolds of lithium (Li)-containing mesoporous bioglass and monomethoxy poly(ethylene glycol)-poly(D,L-lactide-co-glycolide)-poly(L-lysine) (mPEG-PLGA-b-PLL) copolymer were fabricated in this study. The results showed that the water absorption and degradability of Li-containing mesoporous bioglass/mPEG-PLGA-b-PLL composite (l-MBPC) scaffolds were obviously higher than Li-containing bioglass/mPEG-PLGA-b-PLL composite (l-BPC) scaffolds. Moreover, the apatite-formation ability of l-MBPC scaffolds was markedly enhanced as compared with l-BPC scaffolds, indicating that l-MBPC scaffolds containing mesoporous bioglass exhibited good bioactivity. The cell experimental results showed that cell attachment, proliferation, and alkaline phosphatase activity of MC3T3-E1 cells on l-MBPC scaffolds were remarkably improved as compared to l-BPC scaffolds. In animal experiments, the histological elevation results revealed that l-MBPC scaffolds significantly promoted new bone formation, indicating good osteogenesis. l-MBPC scaffolds with improved properties would be an excellent candidate for bone tissue repair.

  11. Degradability, bioactivity, and osteogenesis of biocomposite scaffolds of lithium-containing mesoporous bioglass and mPEG-PLGA-b-PLL copolymer

    PubMed Central

    Cai, Yanrong; Guo, Lieping; Shen, Hongxing; An, Xiaofei; Jiang, Hong; Ji, Fang; Niu, Yunfei

    2015-01-01

    Biocomposite scaffolds of lithium (Li)-containing mesoporous bioglass and monomethoxy poly(ethylene glycol)-poly(D,L-lactide-co-glycolide)-poly(L-lysine) (mPEG-PLGA-b-PLL) copolymer were fabricated in this study. The results showed that the water absorption and degradability of Li-containing mesoporous bioglass/mPEG-PLGA-b-PLL composite (l-MBPC) scaffolds were obviously higher than Li-containing bioglass/mPEG-PLGA-b-PLL composite (l-BPC) scaffolds. Moreover, the apatite-formation ability of l-MBPC scaffolds was markedly enhanced as compared with l-BPC scaffolds, indicating that l-MBPC scaffolds containing mesoporous bioglass exhibited good bioactivity. The cell experimental results showed that cell attachment, proliferation, and alkaline phosphatase activity of MC3T3-E1 cells on l-MBPC scaffolds were remarkably improved as compared to l-BPC scaffolds. In animal experiments, the histological elevation results revealed that l-MBPC scaffolds significantly promoted new bone formation, indicating good osteogenesis. l-MBPC scaffolds with improved properties would be an excellent candidate for bone tissue repair. PMID:26150718

  12. Molecular weight-dependent degradation of D-lactate-containing polyesters by polyhydroxyalkanoate depolymerases from Variovorax sp. C34 and Alcaligenes faecalis T1.

    PubMed

    Sun, Jian; Matsumoto, Ken'ichiro; Tabata, Yuta; Kadoya, Ryosuke; Ooi, Toshihiko; Abe, Hideki; Taguchi, Seiichi

    2015-11-01

    Polyhydroxyalkanoate depolymerase derived from Variovorax sp. C34 (PhaZVs) was identified as the first enzyme that is capable of degrading isotactic P[67 mol% (R)-lactate(LA)-co-(R)-3-hydroxybutyrate(3HB)] [P(D-LA-co-D-3HB)]. This study aimed at analyzing the monomer sequence specificity of PhaZVs for hydrolyzing P(LA-co-3HB) in comparison with a P(3HB) depolymerase from Alcaligenes faecalis T1 (PhaZAf) that did not degrade the same copolymer. Degradation of P(LA-co-3HB) by action of PhaZVs generated dimers, 3HB-3HB, 3HB-LA, LA-3HB, and LA-LA, and the monomers, suggesting that PhaZVs cleaved the linkages between LA and 3HB units and between LA units. To provide a direct evidence for the hydrolysis of these sequences, the synthetic methyl trimers, 3HB-3HB-3HB, LA-LA-3HB, LA-3HB-LA, and 3HB-LA-LA, were treated with the PhaZs. Unexpectedly, not only PhaZVs but also PhaZAf hydrolyzed all of these substrates, namely PhaZAf also cleaved LA-LA linkage. Considering the fact that both PhaZs did not degrade P[(R)-LA] (PDLA) homopolymer, the cleavage capability of LA-LA linkage by PhaZs was supposed to depend on the length of the LA-clustering region in the polymer chain. To test this hypothesis, PDLA oligomers (6 to 40 mer) were subjected to the PhaZ assay, revealing that there was an inverse relationship between molecular weight of the substrates and their hydrolysis efficiency. Moreover, PhaZVs exhibited the degrading activity toward significantly longer PDLA oligomers compared to PhaZAf. Therefore, the cleaving capability of PhaZs used here toward the D-LA-based polymers containing the LA-clustering region was strongly associated with the substrate length, rather than the monomer sequence specificity of the enzyme.

  13. Leak test adapter for containers

    DOEpatents

    Hallett, Brian H.; Hartley, Michael S.

    1996-01-01

    An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

  14. Formation of nitrate and ammonium ions in titanium dioxide mediated photocatalytic degradation of organic compounds containing nitrogen atoms

    SciTech Connect

    Low, G.K.-C.; McEvoy, S.R.; Matthews, R.W. )

    1991-03-01

    The photocatalytic oxidation of a related series of primary, secondary, and tertiary amines and other nitrogen- and sulfur-containing organic compounds over a UV-illuminated film of TiO{sub 2} has been studied. The compounds were as follows: n-pentylamine, piperidine, pyridine, phenylalanine, desipramine, thioridazine, penicillamine, isosorbide dinitrate, 4-nitrocatechol, 2,4-dinitrophenol, cyclophosphamide, 5-fluorouracil, atrazine, ethylenediaminetetracetic acid, and tetrabutylammonium phosphate. Both ammonium and nitrate ions were formed. The relative concentration of the two ions depended on the nature of the nitrogen in a compound, but was also influenced by the illumination time and concentration of the solute. It was found that for n-pentylamine, piperidine and pyridine, the rate of formation of ammonium ions was n-pentylamine {much gt} pyridine > piperidine. The order of rates of nitrate formation was pyridine = piperidine {much gt} pentylamine. For n-pentylamine the rate of formation of ammonium ions was {approximately}100 times that of nitrate.

  15. Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers

    SciTech Connect

    Estill, J C; Farmer, J C; Gordon, S R; McCright, R D

    1998-12-21

    Alloy 22 [UNS NO60221] is now being considered for construction of high level waste containers to be emplaced at Yucca Mountain and elsewhere. In essence, this alloy is 20.0-22.5% Cr, 12.5-14.5% MO, 2.0-6.0% Fe, 2.5-3.5% W, with the balance being Ni. Other impurity elements include P, Si, S, Mn, Co and V. Cobalt may be present at a maximum concentration of 2.5%. Detailed mechanistic models have been developed to account for the corrosion of Alloy 22 surfaces in crevices that will inevitably form. Such occluded areas experience substantial decreases in pH, with corresponding elevations in chloride concentration. Experimental work has been undertaken to validate the crevice corrosion model, including parallel studies with 304 stainless steel.

  16. Human pregnancy serum contains at least two distinct proteolytic activities with the ability to degrade insulin-like growth factor binding protein-3.

    PubMed

    Bang, P; Fielder, P J

    1997-09-01

    The presence of a proteolytic activity in sera from pregnant humans and rodents capable of degrading insulin-like growth factor binding protein-3 (IGFBP-3) has been known for some time. However, the identity of this activity has remained elusive. We have attempted to purify the IGFBP-3 protease activity from pregnant human serum (PHS) using the degradation of 125I-IGFBP-3 as a marker. Following ammonium sulfate precipitation of PHS and further enrichment of active fractions by ion-exchange, protein-A Sepharose, and size-exclusion chromatography, a protease of approximately 70-90 kDa was isolated and subjected to N-terminal analysis. The N-terminal sequence was consistent with plasminogen, a known fibrinolytic enzyme. To further characterize the IGFBP-3 protease activities in both PHS and nonpregnant human serum (NHS), aliquots of serum were first enriched by polyethylene glycol-precipitation and subjected to size-exclusion chromatography. The size-separated fractions were then incubated with 125I-IGFBP-3, and proteolytic activity was measured. PHS contained two separate proteases (>150 kDa and 70-90 kDa), whereas NHS contained only one (70-90 kDa) that had a inhibitor profile similar to plasmin. However, inhibitors of plasmin had no effect on the activity of the >150-kDa protease. Plasminogen activators (PAs) greatly increased the activity of the 70- to 90-kDa protease, but had little effect on the >150-kDa protease activity. Addition of PAs greatly increased the ability of NHS to proteolyze IGFBP-3. In contrast, the ability of plasminogen-depleted plasma to degrade 125I-IGFBP-3 was not affected by the addition of PAs. Both urokinase and tissue-type PA had the ability to proteolyze IGFBP-3 and were, in contrast to the >150-kDa protease activity, inhibited by the specific PA inhibitor D-PHE-PRO-ARG chloromethyl ketone. The present data suggest that sera has the ability to proteolyze IGFBP-3, and that this ability, as demonstrated by NHS, can be regulated by protease

  17. Wipe selection for the analysis of surface materials containing chemical warfare agent nitrogen mustard degradation products by ultra-high pressure liquid chromatography-tandem mass spectrometry.

    PubMed

    Willison, Stuart A

    2012-12-28

    Degradation products arising from nitrogen mustard chemical warfare agent were deposited on common urban surfaces and determined via surface wiping, wipe extraction, and liquid chromatography–tandem mass spectrometry detection. Wipes investigated included cotton gauze, glass fiber filter, non-woven polyester fiber and filter paper, and surfaces included several porous (vinyl tile, painted drywall, wood) and mostly non-porous (laminate, galvanized steel, glass) surfaces. Wipe extracts were analyzed by ultra-high pressure liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) and compared with high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) results. An evaluation of both techniques suggests UPLC–MS/MS provides a quick and sensitive analysis of targeted degradation products in addition to being nearly four times faster than a single HPLC run, allowing for greater throughput during a wide-spread release concerning large-scale contamination and subsequent remediation events. Based on the overall performance of all tested wipes, filter paper wipes were selected over other wipes because they did not contain interferences or native species (TEA and DEA) associated with the target analytes, resulting in high percent recoveries and low background levels during sample analysis. Other wipes, including cotton gauze, would require a pre-cleaning step due to the presence of large quantities of native species or interferences of the targeted analytes. Percent recoveries obtained from a laminate surface were 47–99% for all nitrogen mustard degradation products. The resulting detection limits achieved from wipes were 0.2 ng/cm(2) for triethanolamine (TEA), 0.03 ng/cm(2) for N-ethyldiethanolamine (EDEA), 0.1 ng/cm(2) for N-methyldiethanolamine (MDEA), and 0.1 ng/cm(2) for diethanolamine (DEA).

  18. A novel iron-containing polyoxometalate heterogeneous photocatalyst for efficient 4-chlorophennol degradation by H2O2 at neutral pH

    NASA Astrophysics Data System (ADS)

    Zhai, Qian; Zhang, Lizhong; Zhao, Xiufeng; Chen, Han; Yin, Dongju; Li, Jianhui

    2016-07-01

    An iron-containing polyoxometalate (FeШLysSiW) was synthesized from ferric chloride (FeIII), lysine (Lys) and silicotungstic acid (SiW), and characterized using ICP-AES, TG, FT-IR, UV-vis DRS, XRD and SEM. The chemical formula of FeШLysSiW was determined as [Fe(H2O)5(C6H14N2O2)]HSiW12O40·8H2O, with Keggin-structured SiW12O404- heteropolyanion and lysine moiety. As a heterogeneous catalyst, the as prepared FeШLysSiW showed good performance in the degradation of 4-chlorophenol by H2O2 in both the dark and irradiated systems. Under the conditions of 4-chlorophenol 100 mg/L, FeШLysSiW 1.0 g/L, H2O2 20 mmol/L and pH 6.5, 4-chlorophenol could be completely degraded in ca. 40 min in the dark and ca. 15 min upon irradiation. Prolonging the reaction time to 3 h, the TOC removal reached to ca. 71.3% in the dark and ca. 98.8% under irradiation. The catalytic activity of FeШLysSiW stems from synergetic effect of ferric iron and SiW12O404- in the catalyst, corresponding to Fenton-like catalysis and photocatalysis, respectively. The enhanced degradation of 4-CP under irradiation is due to the simultaneous oxidation of 4-CP through the Fenton-like and photocatalytic processes. The high catalytic activity of FeШLysSiW is also strongly related to the chemisorption of H2O2 on FeШLysSiW surface by hydrogen bonding, which promotes both the Fenton-like and photocatalytic processes.

  19. In vitro degradability, bioactivity and primary cell responses to bone cements containing mesoporous magnesium–calcium silicate and calcium sulfate for bone regeneration

    PubMed Central

    Ding, Yueting; Tang, Songchao; Yu, Baoqing; Yan, Yonggang; Li, Hong; Wei, Jie; Su, Jiacan

    2015-01-01

    Mesoporous calcium sulfate-based bone cements (m-CSBC) were prepared by introducing mesoporous magnesium–calcium silicate (m-MCS) with specific surface area (410.9 m² g−1) and pore volume (0.8 cm³ g−1) into calcium sulfate hemihydrate (CSH). The setting time of the m-CSBC was longer with the increase of m-MCS content while compressive strength decreased. The degradation ratio of m-CSBC increased from 48.6 w% to 63.5 w% with an increase of m-MCS content after soaking in Tris–HCl solution for 84 days. Moreover, the m-CSBC containing m-MCS showed the ability to neutralize the acidic degradation products of calcium sulfate and prevent the pH from dropping. The apatite could be induced on m-CSBC surfaces after soaking in SBF for 7 days, indicating good bioactivity. The effects of the m-CSBC on vitamin D3 sustained release behaviours were investigated. It was found that the cumulative release ratio of vitamin D3 from the m-CSBC significantly increased with the increase of m-MCS content after soaking in PBS (pH = 7.4) for 25 days. The m-CSBC markedly improved the cell-positive responses, including the attachment, proliferation and differentiation of MC3T3-E1 cells, suggesting good cytocompatibility. Briefly, m-CSBC with good bioactivity, degradability and cytocompatibility might be an excellent biocement for bone regeneration. PMID:26423442

  20. In vitro degradability, bioactivity and primary cell responses to bone cements containing mesoporous magnesium-calcium silicate and calcium sulfate for bone regeneration.

    PubMed

    Ding, Yueting; Tang, Songchao; Yu, Baoqing; Yan, Yonggang; Li, Hong; Wei, Jie; Su, Jiacan

    2015-10-06

    Mesoporous calcium sulfate-based bone cements (m-CSBC) were prepared by introducing mesoporous magnesium-calcium silicate (m-MCS) with specific surface area (410.9 m² g(-1)) and pore volume (0.8 cm³ g(-1)) into calcium sulfate hemihydrate (CSH). The setting time of the m-CSBC was longer with the increase of m-MCS content while compressive strength decreased. The degradation ratio of m-CSBC increased from 48.6 w% to 63.5 w% with an increase of m-MCS content after soaking in Tris-HCl solution for 84 days. Moreover, the m-CSBC containing m-MCS showed the ability to neutralize the acidic degradation products of calcium sulfate and prevent the pH from dropping. The apatite could be induced on m-CSBC surfaces after soaking in SBF for 7 days, indicating good bioactivity. The effects of the m-CSBC on vitamin D3 sustained release behaviours were investigated. It was found that the cumulative release ratio of vitamin D3 from the m-CSBC significantly increased with the increase of m-MCS content after soaking in PBS (pH = 7.4) for 25 days. The m-CSBC markedly improved the cell-positive responses, including the attachment, proliferation and differentiation of MC3T3-E1 cells, suggesting good cytocompatibility. Briefly, m-CSBC with good bioactivity, degradability and cytocompatibility might be an excellent biocement for bone regeneration. © 2015 The Author(s).

  1. Derlin-1 and p97/valosin-containing protein mediate the endoplasmic reticulum-associated degradation of human V2 vasopressin receptors.

    PubMed

    Schwieger, Isabel; Lautz, Katja; Krause, Eberhard; Rosenthal, Walter; Wiesner, Burkhard; Hermosilla, Ricardo

    2008-03-01

    The endoplasmic reticulum-associated degradation (ERAD), the main quality control pathway of the cell, is crucial for the elimination of unfolded or misfolded proteins. Several diseases are associated with the retention of misfolded proteins in the early secretory pathway. Among them is X-linked nephrogenic diabetes insipidus, caused by mutations in the gene encoding the V2 vasopressin receptor (V2R). We studied the degradation pathways of three intracellularly retained V2R mutants with different misfolded domains in human embryonic kidney 293 cells. At steady state, the wild-type V2R and the complex-glycosylated mutant G201D were partially located in lysosomes, whereas core-glycosylated mutants L62P and V226E were excluded from this compartment. In pulse-chase experiments, proteasomal inhibition stabilized the nonglycosylated and core-glycosylated forms of all studied receptors. In addition, all mutants and the wild-type receptor were found to be polyubiquitinylated. Nonglycosylated and core-glycosylated receptor forms were located in cytosolic and membrane fractions, respectively, confirming the deglycosylation and retrotranslocation of ERAD substrates to the cytosol. Distinct Derlin-1-dependent and -independent ERAD pathways have been proposed for proteins with different misfolded domains (cytosolic, extracellular, and membrane) in yeast. Here, we show for the first time that V2R mutants with different misfolded domains are able to coprecipitate the ERAD components p97/valosin-containing protein, Derlin-1 and the 26S proteasome regulatory subunit 7. Our results demonstrate the presence of a Derlin-1-mediated ERAD pathway degrading wild-type and disease-causing V2R mutants with different misfolded domains in a mammalian system.

  2. A New Class of Tungsten-Containing Oxidoreductase in Caldicellulosiruptor, a Genus of Plant Biomass-Degrading Thermophilic Bacteria

    PubMed Central

    Scott, Israel M.; Rubinstein, Gabe M.; Lipscomb, Gina L.; Basen, Mirko; Schut, Gerrit J.; Rhaesa, Amanda M.; Lancaster, W. Andrew; Poole, Farris L.; Kelly, Robert M.

    2015-01-01

    Caldicellulosiruptor bescii grows optimally at 78°C and is able to decompose high concentrations of lignocellulosic plant biomass without the need for thermochemical pretreatment. C. bescii ferments both C5 and C6 sugars primarily to hydrogen gas, lactate, acetate, and CO2 and is of particular interest for metabolic engineering applications given the recent availability of a genetic system. Developing optimal strains for technological use requires a detailed understanding of primary metabolism, particularly when the goal is to divert all available reductant (electrons) toward highly reduced products such as biofuels. During an analysis of the C. bescii genome sequence for oxidoreductase-type enzymes, evidence was uncovered to suggest that the primary redox metabolism of C. bescii has a completely uncharacterized aspect involving tungsten, a rarely used element in biology. An active tungsten utilization pathway in C. bescii was demonstrated by the heterologous production of a tungsten-requiring, aldehyde-oxidizing enzyme (AOR) from the hyperthermophilic archaeon Pyrococcus furiosus. Furthermore, C. bescii also contains a tungsten-based AOR-type enzyme, here termed XOR, which is phylogenetically unique, representing a completely new member of the AOR tungstoenzyme family. Moreover, in C. bescii, XOR represents ca. 2% of the cytoplasmic protein. XOR is proposed to play a key, but as yet undetermined, role in the primary redox metabolism of this cellulolytic microorganism. PMID:26276113

  3. A New Class of Tungsten-Containing Oxidoreductase in Caldicellulosiruptor, a Genus of Plant Biomass-Degrading Thermophilic Bacteria.

    PubMed

    Scott, Israel M; Rubinstein, Gabe M; Lipscomb, Gina L; Basen, Mirko; Schut, Gerrit J; Rhaesa, Amanda M; Lancaster, W Andrew; Poole, Farris L; Kelly, Robert M; Adams, Michael W W

    2015-10-01

    Caldicellulosiruptor bescii grows optimally at 78°C and is able to decompose high concentrations of lignocellulosic plant biomass without the need for thermochemical pretreatment. C. bescii ferments both C5 and C6 sugars primarily to hydrogen gas, lactate, acetate, and CO2 and is of particular interest for metabolic engineering applications given the recent availability of a genetic system. Developing optimal strains for technological use requires a detailed understanding of primary metabolism, particularly when the goal is to divert all available reductant (electrons) toward highly reduced products such as biofuels. During an analysis of the C. bescii genome sequence for oxidoreductase-type enzymes, evidence was uncovered to suggest that the primary redox metabolism of C. bescii has a completely uncharacterized aspect involving tungsten, a rarely used element in biology. An active tungsten utilization pathway in C. bescii was demonstrated by the heterologous production of a tungsten-requiring, aldehyde-oxidizing enzyme (AOR) from the hyperthermophilic archaeon Pyrococcus furiosus. Furthermore, C. bescii also contains a tungsten-based AOR-type enzyme, here termed XOR, which is phylogenetically unique, representing a completely new member of the AOR tungstoenzyme family. Moreover, in C. bescii, XOR represents ca. 2% of the cytoplasmic protein. XOR is proposed to play a key, but as yet undetermined, role in the primary redox metabolism of this cellulolytic microorganism. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. Degradability, biocompatibility, and osteogenesis of biocomposite scaffolds containing nano magnesium phosphate and wheat protein both in vitro and in vivo for bone regeneration

    PubMed Central

    Xia, Yan; Zhou, Panyu; Wang, Fei; Qiu, Chao; Wang, Panfeng; Zhang, Yuntong; Zhao, Liming; Xu, Shuogui

    2016-01-01

    In this study, bioactive scaffold of nano magnesium phosphate (nMP)/wheat protein (WP) composite (MWC) was fabricated. The results revealed that the MWC scaffolds had interconnected not only macropores (sized 400–600 μm) but also micropores (sized 10–20 μm) on the walls of macropores. The MWC scaffolds containing 40 w% nMP had an appropriate degradability in phosphate-buffered saline and produced a weak alkaline microenvironment. In cell culture experiments, the results revealed that the MWC scaffolds significantly promoted the MC3T3-E1 cell proliferation, differentiation, and growth into the scaffolds. The results of synchrotron radiation microcomputed tomography and analysis of the histological sections of the in vivo implantation revealed that the MWC scaffolds evidently improved the new bone formation and bone defects repair as compared with WP scaffolds. Moreover, it was found that newly formed bone tissue continued to increase with the gradual reduction of materials residual in the MWC scaffolds. Furthermore, the immunohistochemical analysis further offered the evidence of the stimulatory effects of MWC scaffolds on osteogenic-related cell differentiation and new bone regeneration. The results indicated that MWC scaffolds with good biocompability and degradability could promote osteogenesis in vivo, which would have potential for bone tissue repair. PMID:27555766

  5. Anti-ageing effects of dentifrices containing anti-oxidative, anti-inflammatory, and anti-bacterial agents (Tomarina®) on gingival collagen degradation in rats.

    PubMed

    Koichiro, Irie; Tomofuji, Takaaki; Ekuni, Daisuke; Endo, Yasumasa; Kasuyama, Kenta; Azuma, Tetsuji; Tamaki, Naofumi; Yoneda, Toshiki; Morita, Manabu

    2014-01-01

    Previous studies have demonstrated the relationship between ageing and oxidative stress. In this study, we examined the effects of topical application of a dentifrice containing anti-oxidative, anti-inflammatory, and anti-bacterial agents (Tomarina®) to the gingival surface on gingival collagen degradation in rats. Fischer 344 male rats (4 or 8 months old) were divided into two groups: experimental group and control group. Tomarina® (the experimental group) or control dentifrice (the control group) was applied 5 days per week for 2 months. In the control group, gingival collagen density decreased with ageing. In the experimental group, the collagen density did not change with ageing, and was greater than that in the control group at 10 months of age (p < 0.0083). In addition, the control group showed an increase in serum oxidative stress with ageing. The experimental group also showed increased serum oxidative stress, but the value was lower than the control group at 10 months of age (p < 0.0083). Furthermore, low expressions of protein oxidative damage in the periodontal tissue were observed in the experimental group, compared to the control group at 6 months and 10 months. These findings indicate that Tomarina® might suppress the effects of ageing on gingival collagen degradation, by decreasing oxidative stress in the rat model.

  6. A conserved serine residue regulates the stability of Drosophila Salvador and human WW domain-containing adaptor 45 through proteasomal degradation

    SciTech Connect

    Wu, Di Wu, Shian

    2013-04-19

    Highlights: •Ser-17 is key for the stability of Drosophila Sav. •Ala mutation of Ser-17 promotes the proteasomal degradation of Sav. •Ser-17 residue is not the main target of Hpo-induced Sav stabilization. •Hpo-dependent and -independent mechanisms regulate Sav stability. •This mechanism is conserved in the homologue of Sav, human WW45. -- Abstract: The Hippo (Hpo) pathway is a conserved tumor suppressor pathway that controls organ size through the coordinated regulation of apoptosis and proliferation. Drosophila Salvador (Sav), which limits organ size, is a core component of the Hpo pathway. In this study, Ser-17 was shown to be important for the stability of Sav. Alanine mutation of Ser-17 promoted the proteasomal degradation of Sav. Destabilization and stabilization of the Sav protein mediated by alanine mutation of Ser-17 and by Hpo, respectively, were independent of each other. This implies that the stability of Sav is controlled by two mechanisms, one that is Ser-17-dependent and Hpo-independent, and another that is Ser-17-independent and Hpo-dependent. These dual mechanisms also regulated the human counterpart of Drosophila Sav, WW domain-containing adaptor 45 (WW45). The conservation of this regulation adds to its significance in normal physiology and tumorigenesis.

  7. Isolation and characterization of dimethyl sulfide (DMS)-degrading bacteria from soil and biofilter treating waste gas containing DMS from the laboratory and pulp and paper industry.

    PubMed

    Giri, Balendu Shekher; Juwarkar, Asha A; Satpute, D B; Mudliar, S N; Pandey, R A

    2012-07-01

    Dimethyl sulfide (DMS) is one of the sulfurous pollutants present in the waste gas generated from the pulp and paper industry. DMS has environmental health implications; therefore, it is necessary to treat the waste gas containing DMS prior to discharge into the environment. A bench-scale biofilter was operated in the laboratory as well as in a pulp and paper industry for the treatment of DMS. Both the biofilters were packed with pre-sterilized wood chips and cow dung/compost of the same origin seeded with biomass developed from garden soil enriched with DMS. The biofilters were operated for the generation of process parameters, and the potential microorganisms isolated from both the biofilters have been purified and characterized for degradation of DMS. Further, these cultures were purified on a basal medium using DMS as a sole carbon source for the growth. Further, the purified cultures were characterized through standard fatty acid methyl esters (FAME)-gas chromatography method, and the isolates were found to be mesophilic, aerobic microbes. These microbes were identified as Bacillus sphaericus-GC subgroup F, Paenibacillus polymyxa, B. sphaericus-GC subgroup F, B. sphaericus-GC subgroup F, and Bacillus megaterium-GC subgroup A, respectively. The potential culture for degradation of DMS was identified as B. sphaericus by 16s rRNA molecular analysis.

  8. α/β Hydrolase Domain-containing 6 (ABHD6) Degrades the Late Endosomal/Lysosomal Lipid Bis(monoacylglycero)phosphate*

    PubMed Central

    Pribasnig, Maria A.; Mrak, Irina; Grabner, Gernot F.; Taschler, Ulrike; Knittelfelder, Oskar; Scherz, Barbara; Eichmann, Thomas O.; Heier, Christoph; Grumet, Lukas; Kowaliuk, Jakob; Romauch, Matthias; Holler, Stefan; Anderl, Felix; Wolinski, Heimo; Lass, Achim; Breinbauer, Rolf; Marsche, Gunther; Brown, J. Mark; Zimmermann, Robert

    2015-01-01

    α/β Hydrolase domain-containing 6 (ABHD6) can act as monoacylglycerol hydrolase and is believed to play a role in endocannabinoid signaling as well as in the pathogenesis of obesity and liver steatosis. However, the mechanistic link between gene function and disease is incompletely understood. Here we aimed to further characterize the role of ABHD6 in lipid metabolism. We show that mouse and human ABHD6 degrade bis(monoacylglycero)phosphate (BMP) with high specific activity. BMP, also known as lysobisphosphatidic acid, is enriched in late endosomes/lysosomes, where it plays a key role in the formation of intraluminal vesicles and in lipid sorting. Up to now, little has been known about the catabolism of this lipid. Our data demonstrate that ABHD6 is responsible for ∼90% of the BMP hydrolase activity detected in the liver and that knockdown of ABHD6 increases hepatic BMP levels. Tissue fractionation and live-cell imaging experiments revealed that ABHD6 co-localizes with late endosomes/lysosomes. The enzyme is active at cytosolic pH and lacks acid hydrolase activity, implying that it degrades BMP exported from acidic organelles or de novo-formed BMP. In conclusion, our data suggest that ABHD6 controls BMP catabolism and is therefore part of the late endosomal/lysosomal lipid-sorting machinery. PMID:26491015

  9. Study of nitrile-containing proton exchange membranes prepared by radiation grafting: Performance and degradation in the polymer electrolyte fuel cell

    NASA Astrophysics Data System (ADS)

    Zhang, Zhuoxiang; Jetsrisuparb, Kaewta; Wokaun, Alexander; Gubler, Lorenz

    2013-12-01

    The fuel cell performance and durability of three kinds of styrene based radiation grafted membranes are investigated and compared in the single cell. The styrene/methacrylonitrile (MAN) co-grafted membrane exhibits the best performance among the tested radiation grafted membranes. The accelerated tests under open circuit voltage (OCV) conditions and post-mortem analysis demonstrate that the nitrile-containing membranes exhibit significantly enhanced durability compared to the pure styrene grafted membrane, which is associated with the reduced gas crossover rates and attributed to the improved gases barrier properties due to the polarity of the nitrile group. To understand the influence of each functional group in the co-monomer units, both styrene/MAN and styrene/acrylonitrile (AN) co-grafted membranes are evaluated in a set of tests at OCV. The degrees of loss of the graft components are subsequently quantitatively analyzed based on FTIR spectra, showing a comparable decomposition rate of grafted styrene units, but more loss of nitrile in case of the styrene/AN co-grafted membrane. The styrene/AN co-grafted membrane, with AN lacking protection at the α-position in contrast to MAN, is found to be susceptible to significant hydrolysis, directly leading to an accelerated degradation in the late stages of the 130 h OCV test and inhomogeneous in-plane degradation.

  10. Controlled synthesis of uniform BiVO4 microcolumns and advanced visible-light-driven photocatalytic activity for the degradation of metronidazole-contained wastewater.

    PubMed

    Yu, Chongfei; Dong, Shuying; Feng, Jinglan; Sun, Jingyu; Hu, Limin; Li, Yukun; Sun, Jianhui

    2014-02-01

    Well-defined, uniform bismuth vanadate (BiVO4) microcolumns were synthesized through a refined hydrothermal route. During the fabrication process, a detailed orthogonal design on the synthetic conditions was performed, aiming to optimize the experimental parameters to produce BiVO4 materials (BiVO4 (Opt.)) with the most prominent visible-light-driven photocatalytic efficiency, where the catalytic activities of the synthesized materials were evaluated via the decolorization of methylene blue under visible light irradiation. The BiVO4 (Opt.) were then targetedly produced according to the determined optimal conditions and well characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet and visible diffuse-reflectance spectroscopy and photoluminescence spectroscopy. Compared with the commercial P25-TiO2 photocatalysts, the as-synthesized BiVO4 (Opt.) displayed superior visible-light-driven photocatalytic activities for the degradation of metronidazole-contained wastewater with the presence of H2O2. The degradation efficiency of metronidazole reached up to 70 % within 180 min, leading to a brief speculation on the possibly major steps of the visible-light-driven photocatalytic process. The current study provides a distinctive route to design novel shaped BiVO4 architectures with advanced photocatalytic capacities for the treatment of organic pollutants in the aqueous environment.

  11. A conserved serine residue regulates the stability of Drosophila Salvador and human WW domain-containing adaptor 45 through proteasomal degradation.

    PubMed

    Wu, Di; Wu, Shian

    2013-04-19

    The Hippo (Hpo) pathway is a conserved tumor suppressor pathway that controls organ size through the coordinated regulation of apoptosis and proliferation. Drosophila Salvador (Sav), which limits organ size, is a core component of the Hpo pathway. In this study, Ser-17 was shown to be important for the stability of Sav. Alanine mutation of Ser-17 promoted the proteasomal degradation of Sav. Destabilization and stabilization of the Sav protein mediated by alanine mutation of Ser-17 and by Hpo, respectively, were independent of each other. This implies that the stability of Sav is controlled by two mechanisms, one that is Ser-17-dependent and Hpo-independent, and another that is Ser-17-independent and Hpo-dependent. These dual mechanisms also regulated the human counterpart of Drosophila Sav, WW domain-containing adaptor 45 (WW45). The conservation of this regulation adds to its significance in normal physiology and tumorigenesis.

  12. Chemical penetration enhancers.

    PubMed

    Newton, Stephen J

    2013-01-01

    Chemical penetration enhancers are utilized in topical preparations as a method for enhancing permeation of drugs across the skin. In particular, they are utilized for transdermal delivery of medications in an attempt to produce a systemic response, to avoid first-pass metabolism, and to decrease the gastrointestinal transit time observed with oral medications. A review of the selection of chemical penetration enhancers, their mechanism of action, the most common chemical penetration enhancers in each class, and alternatives will be discussed in detail.

  13. Investigating differences in the ability of XplA/B-containing bacteria to degrade the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX).

    PubMed

    Sabir, Dana Khdr; Grosjean, Nicolas; Rylott, Elizabeth L; Bruce, Neil C

    2017-08-01

    The xenobiotic hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a toxic explosive and environmental pollutant. This study examines three bacterial species that degrade RDX, using it as a sole source of nitrogen for growth. Although isolated from diverse geographical locations, the species contain near identical copies of genes encoding the RDX-metabolising cytochrome P450, XplA and accompanying reductase, XplB. Sequence analysis indicates a single evolutionary origin for xplA and xplB as part of a genomic island, which has been distributed around the world via horizontal gene transfer. Despite the fact that xplA and xplB are highly conserved between species, Gordonia sp. KTR9 and Microbacterium sp. MA1 degrade RDX more slowly than Rhodococcus rhodochrous 11Y. Both Gordonia sp. KTR9 and Microbacterium sp. MA1 were found to contain single base-pair mutations in xplB which, following expression and purification, were found to encode inactive XplB protein. Additionally, the Gordonia sp. KTR9 XplB was fused to glutamine synthetase, which would be likely to sterically inhibit XplB activity. Although the glutamine synthetase is fused to XplB and truncated by 71 residues, it was found to be active. Glutamine synthetase has been implicated in the regulation of nitrogen levels; controlling nitrogen availability will be important for effective bioremediation of RDX. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Penetration Testing of the OPRA Regolith Penetrator

    NASA Astrophysics Data System (ADS)

    El Shafie, A.; Kegege, O.; Barrows, S.; Roe, L.; Ulrich, R.

    2008-03-01

    Our work focuses on the mechanical design and penetration forces for the Optical Probe for Regolith Analysis. This is a spike-shaped probe delivered to a planet, asteroid, or cometary body by a lander to provide IR spectroscopy of the subsurface.

  15. Follicular penetration and targeting.

    PubMed

    Lademann, Jürgen; Otberg, Nina; Jacobi, Ute; Hoffman, Robert M; Blume-Peytavi, Ulrike

    2005-12-01

    In the past, intercellular penetration was assumed to be the most important penetration pathway of topically applied substances. First hints that follicular penetration needs to be taken into consideration were confirmed by recent investigations, presented during the workshop "Follicular Penetration and Targeting" at the 4th Intercontinental Meeting of Hair Research Societies", in Berlin 2004. Hair follicles represent an efficient reservoir for the penetration of topically applied substances with subsequent targeting of distinct cell populations, e.g., nestin-expressing follicular bulge cells. The volume of this reservoir can be determined by differential stripping technology. The follicular penetration processes are significantly influenced by the state of the follicular infundibulum; recent experimental investigations could demonstrate that it is essential to distinguish between open and closed hair follicles. Topically applied substances can only penetrate into open hair follicle. Knowledge of follicular penetration is of high clinical relevance for functional targeting of distinct follicular regions. Human hair follicles show a hair-cycle-dependent variation of the dense neuronal and vascular network. Moreover, during hair follicle cycling with initiation of anagen, newly formed vessels occur. Thus, the potential of nestin-expressing hair follicle stem cells to form neurons and blood vessels was investigated.

  16. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  17. Thermomechanics of Impact & Penetration

    DTIC Science & Technology

    2005-09-30

    metallic projectiles into granular targets, at high striking velocities, formulate appropriate constitutive models , and solve selected problems by...constitutive models (preliminary work only) * Multiscale Numerical Simulations (preliminary work) PROGRESS Time-Dependent Penetration Path of...theory. A dislocation based plasticity model was also developed for the impact and penetration analysis. Numerical solutions were presented for selected

  18. International Spread and Persistence of TEM-24 Is Caused by the Confluence of Highly Penetrating Enterobacteriaceae Clones and an IncA/C2 Plasmid Containing Tn1696::Tn1 and IS5075-Tn21▿

    PubMed Central

    Novais, Ângela; Baquero, Fernando; Machado, Elisabete; Cantón, Rafael; Peixe, Luísa; Coque, Teresa M.

    2010-01-01

    TEM-24 remains one of the most widespread TEM-type extended-spectrum β-lactamases (ESBLs) among Enterobacteriaceae. To analyze the reasons influencing its spread and persistence, a multilevel population genetics study was carried out on 28 representative TEM-24 producers from Belgium, France, Portugal, and Spain (13 Enterobacter aerogenes isolates, 6 Escherichia coli isolates, 6 Klebsiella pneumoniae isolates, 2 Proteus mirabilis isolates, and 1 Klebsiella oxytoca isolate, from 1998 to 2004). Clonal relatedness (XbaI pulsed-field gel electrophoresis [PFGE] and E. coli phylogroups) and antibiotic susceptibility were determined by standard procedures. Plasmid analysis included determination of the incompatibility group (by PCR, hybridization, and/or sequencing) and comparison of restriction fragment length polymorphism (RFLP) patterns. Characterization of genetic elements conferring antibiotic resistance included integrons (classes 1, 2, and 3) and transposons (Tn3, Tn21, and Tn402). Similar PFGE patterns were identified among E. aerogenes, K. pneumoniae, and P. mirabilis isolates, while E. coli strains were diverse (phylogenetic groups A, B2, and D). Highly related 180-kb IncA/C2 plasmids conferring resistance to kanamycin, tobramycin, chloramphenicol, trimethoprim, and sulfonamides were identified. Each plasmid contained defective In0-Tn402 (dfrA1-aadA1, aacA4, or aacA4-aacC1-orfE-aadA2-cmlA1) and In4-Tn402 (aacA4 or dfrA1-aadA1) variants. These integrons were located within Tn21, Tn1696, or hybrids of these transposons, with IS5075 interrupting their IRtnp and IRmer. In all cases, blaTEM-24 was part of an IS5075-ΔTn1 transposon within tnp1696, mimicking other genetic elements containing blaTEM-2 and blaTEM-3 variants. The international dissemination of TEM-24 is fuelled by an IncA/C2 plasmid acquired by different enterobacterial clones which seem to evolve by gaining diverse genetic elements. This work highlights the risks of a confluence between highly

  19. Lycopene degradation, isomerization and in vitro bioaccessibility in high pressure homogenized tomato puree containing oil: effect of additional thermal and high pressure processing.

    PubMed

    Knockaert, Griet; Pulissery, Sudheer K; Colle, Ines; Van Buggenhout, Sandy; Hendrickx, Marc; Loey, Ann Van

    2012-12-01

    In the present study, the effect of equivalent thermal and high pressure processes at pasteurization and sterilization intensities on some health related properties of high pressure homogenized tomato puree containing oil were investigated. Total lycopene concentration, cis-lycopene content and in vitro lycopene bioaccessibility were examined as health related properties. Results showed that pasteurization hardly affected the health related properties of tomato puree. Only the formation of cis-lycopene during intense thermal pasteurization was observed. Sterilization processes on the other hand had a significant effect on the health related properties. A significant decrease in total lycopene concentration was found after the sterilization processes. Next to degradation, significant isomerization was also observed: all-trans-lycopene was mainly converted to 9-cis- and 13-cis-lycopene. High pressure sterilization limited the overall lycopene isomerization, when compared to the equivalent thermal sterilization processes. The formation of 5-cis-lycopene on the other hand seemed to be favoured by high pressure. The in vitro lycopene bioaccessibility of high pressure homogenized tomato puree containing oil was decreased during subsequent thermal or high pressure processing, whereby significant changes were observed for all the sterilization processes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Atg6/UVRAG/Vps34-Containing Lipid Kinase Complex Is Required for Receptor Downregulation through Endolysosomal Degradation and Epithelial Polarity during Drosophila Wing Development

    PubMed Central

    Szatmári, Zsuzsanna; Sass, Miklós

    2014-01-01

    Atg6 (Beclin 1 in mammals) is a core component of the Vps34 PI3K (III) complex, which promotes multiple vesicle trafficking pathways. Atg6 and Vps34 form two distinct PI3K (III) complexes in yeast and mammalian cells, either with Atg14 or with UVRAG. The functions of these two complexes are not entirely clear, as both Atg14 and UVRAG have been suggested to regulate both endocytosis and autophagy. In this study, we performed a microscopic analysis of UVRAG, Atg14, or Atg6 loss-of-function cells in the developing Drosophila wing. Both autophagy and endocytosis are seriously impaired and defective endolysosomes accumulate upon loss of Atg6. We show that Atg6 is required for the downregulation of Notch and Wingless signaling pathways; thus it is essential for normal wing development. Moreover, the loss of Atg6 impairs cell polarity. Atg14 depletion results in autophagy defects with no effect on endocytosis or cell polarity, while the silencing of UVRAG phenocopies all but the autophagy defect of Atg6 depleted cells. Thus, our results indicate that the UVRAG-containing PI3K (III) complex is required for receptor downregulation through endolysosomal degradation and for the establishment of proper cell polarity in the developing wing, while the Atg14-containing complex is involved in autophagosome formation. PMID:25006588

  1. Characterization and functional assessment of Clostridium histolyticum class I (C1) collagenases and the synergistic degradation of native collagen in enzyme mixtures containing class II (C2) collagenase.

    PubMed

    Breite, A G; McCarthy, R C; Dwulet, F E

    2011-11-01

    Clostridium histolyticum expresses two classes of collagenases, C1 and C2. However, degradation of these enzymes by proteases during the fermentation or purification process may lead to numerous molecular forms that lead to inconsistent release of islets from human pancreata. This report defines the amino acid sequence of the truncated forms of C1 (C1b or C1c) that contain a single collagen-binding domain (CBD) and investigates the synergy between the different forms of C1 collagenase and C2 to degrade native collagen. Highly purified collagenase isoforms were purified from C. histolyticum culture supernatants using established column chromatography techniques and analyzed using high-pressure liquid chromatograph (HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry (MS). The collagen-degrading activity (CDA) assay was used to investigate the synergy between different collagenase molecular forms. MS was used to confirm the sequence of full-length C2 and C1 from the reported gene sequence. These results were correlated with the molecular weights observed on the SDS- PAGE and elution after analytical anion-exchange HPLC. HPLC peaks designated as C1b and C1c were both confirmed to be C1 lacking the terminal CBD. The only difference being the cleavage site leading to a 12 amino acid difference between the two forms. A non-additive synergy in CDA relative to activity of individual collagenases was observed for C2 with each of the three C1 molecular forms. The C1 molecular forms did not display this synergy in the absence of C2. These observations support earlier reports that suggest the two collagenases bind to different portions of the collagen and have different specificities to cut native collagen. Although the implications of this are not yet understood, they are fundamental in advancing the understanding of how collagenases work together along with the neutral protease to breakdown the extracellular matrix for islet

  2. Severe accident testing of electrical penetration assemblies

    SciTech Connect

    Clauss, D.B. )

    1989-11-01

    This report describes the results of tests conducted on three different designs of full-size electrical penetration assemblies (EPAs) that are used in the containment buildings of nuclear power plants. The objective of the tests was to evaluate the behavior of the EPAs under simulated severe accident conditions using steam at elevated temperature and pressure. Leakage, temperature, and cable insulation resistance were monitored throughout the tests. Nuclear-qualified EPAs were produced from D. G. O'Brien, Westinghouse, and Conax. Severe-accident-sequence analysis was used to generate the severe accident conditions (SAC) for a large dry pressurized-water reactor (PWR), a boiling-water reactor (BWR) Mark I drywell, and a BWR Mark III wetwell. Based on a survey conducted by Sandia, each EPA was matched with the severe accident conditions for a specific reactor type. This included the type of containment that a particular EPA design was used in most frequently. Thus, the D. G. O'Brien EPA was chosen for the PWR SAC test, the Westinghouse was chosen for the Mark III test, and the Conax was chosen for the Mark I test. The EPAs were radiation and thermal aged to simulate the effects of a 40-year service life and loss-of-coolant accident (LOCA) before the SAC tests were conducted. The design, test preparations, conduct of the severe accident test, experimental results, posttest observations, and conclusions about the integrity and electrical performance of each EPA tested in this program are described in this report. In general, the leak integrity of the EPAs tested in this program was not compromised by severe accident loads. However, there was significant degradation in the insulation resistance of the cables, which could affect the electrical performance of equipment and devices inside containment at some point during the progression of a severe accident. 10 refs., 165 figs., 16 tabs.

  3. Advanced Penetrator Materials

    DTIC Science & Technology

    2007-11-02

    development • Uranium (U-V-X) Alloys • Alternative Matrix (adiabatic shearing) Tungsten Composites • Amorphous and Nanocrystalline Alloys • Severe Deformation...WIDER CHANNEL • MUSHROOM NOSE • LESS DEPTH • REMAINS SHARP • NARROW CHANNEL • DEEPER CAVITY TUNGSTEN HEAVY ALLOY U-3/4 Ti ALLOY U-8Mo ALLOYW-Ni-Fe...martensite (from Staker)(from Staker) • U-V alloys have the potential to maintain penetration capability while reducing penetrator density and mass. Tungsten

  4. Ankyrin repeat and suppressor of cytokine signaling box containing protein-10 is associated with ubiquitin-mediated degradation pathways in trabecular meshwork cells.

    PubMed

    Keller, Kate E; Yang, Yong-Feng; Sun, Ying Ying; Sykes, Renee; Acott, Ted S; Wirtz, Mary K

    2013-01-01

    Ankyrin repeat and suppressor of cytokine signaling (SOCS) box containing protein-10 (ASB10) was recently identified as a gene that causes primary open-angle glaucoma. Here, we investigated endogenous ASB10 protein expression in human trabecular meshwork (HTM) cells to provide the first clues to the biologic function of this protein. Primary HTM cells were cultured and immunostained with anti-ASB10 and various biomarkers of the ubiquitin-mediated proteasomal and autophagy-lysosomal degradation pathways. Cells were imaged with confocal and high-resolution structured illumination microscopy. Colocalization was quantified using Imaris Bitplane software, which generated a Pearson's correlation coefficient value. Coimmunoprecipitation of ASB10-transfected cells was performed. Immunofluorescence and confocal analysis showed that ASB10 was localized in intracellular structures in HTM cells. Two populations were observed: small, spherical vesicles and larger, less abundant structures. In the ASB10-silenced cells, the number of large structures was significantly decreased. ASB10 partially colocalized with biomarkers of the ubiquitin-mediated proteasomal pathway including ubiquitin and the α4 subunit of the 20S proteasome. However, ASB10 itself was not ubiquitinated. ASB10 also colocalized with numerous biomarkers of specific autophagic structures: aggresomes (histone deacetylase 6 [HDAC6] and heat shock protein 70 [HSP70]), autophagosomes (light chain 3 [LC3] and p62), amphisomes (Rab7), and lysosomes (lysosomal-associated membrane protein 1 [LAMP1]). Pearson coefficients indicated strong colocalization of large ASB10-stained structures with the α4 subunit of the 20S proteasome, K48 and K63-linked ubiquitin antibodies, p62, HSP70, and HDAC6 (Pearson's range, 0.59-0.82). Coimmunoprecipitation assays showed a positive interaction of ASB10 with HSP70 and with the α4 subunit of the 20S proteasome. Super-resolution structured illumination confocal microscopy suggested that

  5. Computational fluid dynamic analysis of a closure head penetration in a pressurized water reactor

    SciTech Connect

    Forsyth, D.R.; Schwirian, R.E.

    1995-09-01

    ALLOY 600 has been used typically for penetrations through the closure head in pressurized water reactors because of its thermal compatibility with carbon steel, superior resistance to chloride attack and higher strength than the austenitic stainless steels. Recent plant operating experience with this alloy has indicated that this material may be susceptible to degradation. One of the major parameters relating to degradation of the head penetrations are the operational temperatures and stress levels in the penetration.

  6. THE KINETICS OF PENETRATION

    PubMed Central

    Osterhout, W. J. V.; Kamerling, S. E.

    1934-01-01

    A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external

  7. Degradation of the herbicide 2, 4-dichlorophenoxyacetic acid (2,4-D) dimethylamine salt by gamma radiation from cobalt-60 in aqueous solution containing humic acid

    NASA Astrophysics Data System (ADS)

    Campos, Sandro X.; Vieira, Eny M.; Cordeiro, Paulo J. M.; Rodrigues-Fo, Edson; Murgu, Michael

    2003-12-01

    In this study, gamma radiation from cobalt-60 was used to degrade the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) dimethylamine salt in water in the presence of humic acid. The 2,4-D dimethylamine salt 1.13×10 -4 mol dm -3 solution was irradiated with different doses. HPLC was used as an analytical technique to determine the degradation rate of herbicide studied. The results showed that the herbicide was completely degraded at an absorbed dose of 3 kGy. Degradation decreased when humic acid was added to all the doses. ESI/MS and MS/MS were used to identify the radiolytic degradation products. A fragmentation path for production of 4.6-dichlororesorcinol, is suggested. The radiolytic yields ( G) were calculated.

  8. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  9. Field solar degradation of pesticides and emerging water contaminants mediated by polymer films containing titanium and iron oxide with synergistic heterogeneous photocatalytic activity at neutral pH.

    PubMed

    Mazille, F; Schoettl, T; Klamerth, N; Malato, S; Pulgarin, C

    2010-05-01

    Photocatalytic degradation of phenol, nalidixic acid, mixture of pesticides, and another of emerging contaminants in water was mediated by TiO(2) and iron oxide immobilized on functionalized polyvinyl fluoride films (PVF(f)-TiO(2)-Fe oxide) in a compound parabolic collector (CPC) solar photoreactor. During degradation, little iron leaching (<0.2mgL(-1)) was observed. Phenol was efficiently degraded and mineralized at operational pH<5 and nalidixic acid degradation was complete even at pH 7, but mineralization stopped at 35%. Pesticide mixture was slowly degraded (50%) after 150min of irradiation. Degradation of the emergent contaminant mixture was successful for eight compounds and less efficient for six other compounds. The significant reactivity differences between tested compounds were assigned to the differences in structure namely that the presence of complexing or chelating groups enhanced the rates. PVF(f)-TiO(2)-Fe oxide photoactivity gradually increased during 20 days of experiments. X-ray photoelectron spectroscopy (XPS) measurements revealed significant changes on the catalyst surface. These analyses confirm that during photocatalysis mediated by PVF(f)-TiO(2)-Fe oxide, some iron leaching led to enlargement of the TiO(2) surface exposed to light, increasing its synergy with iron oxides and leading to enhanced pollutant degradation.

  10. New pseudopeptidic cross-linker containing urea bonds: study of its degradation routes in aqueous media using capillary electrophoresis-mass spectrometry.

    PubMed

    Pérez, Paloma; Simó, Carolina; Neusüss, Christian; Pelzing, Matthias; San Roman, Julio; Cifuentes, Alejandro; Gallardo, Alberto

    2006-03-01

    An accelerated degradation study has been performed on TLT, a pseudopeptide that includes esterified tyrosine and lysine linked by urea bonds, as well as on their derivatives, i.e., a dimethacrylic cross-linker (DMTLT) and a poly(dimethylacrylamide) cross-linked with DMTLT. The monitoring and analytical characterization has been carried out by capillary electrophoresis-mass spectrometry (CE-MS), using ion trap and time-of-flight MS analyzers. Several degradative species have been identified, and a kinetic analysis of the variation of their concentration with time has been obtained. During the initial stages of degradation, there is a competition between hydrolysis of the ester groups and cyclization by nucleophilic attack of the NHs of the urea groups to the carbonyl ester group. At higher degradation time (weeks or months), evidences of backbone breakdown, including urea hydrolysis, have been found.

  11. Microencapsulated Fluorescent Dye Penetrant.

    DTIC Science & Technology

    1979-07-01

    Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

  12. Penetration resistant barrier

    DOEpatents

    Hoover, William R.; Mead, Keith E.; Street, Henry K.

    1977-01-01

    The disclosure relates to a barrier for resisting penetration by such as hand tools and oxy-acetylene cutting torches. The barrier comprises a layer of firebrick, which is preferably epoxy impregnated sandwiched between inner and outer layers of steel. Between the firebrick and steel are layers of resilient rubber-like filler.

  13. Soil penetrometers and penetrability

    USDA-ARS?s Scientific Manuscript database

    Soil penetrometers are useful tools that measure the penetrability, or strength, of a soil. They can be as simple as a rod or shaft with a blunt or sharp end, or complicated mechanically driven instruments with digital data collection systems. Regardless of their design, soil penetrometers measure s...

  14. Single wall penetration equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    1991-01-01

    Five single plate penetration equations are compared for accuracy and effectiveness. These five equations are two well-known equations (Fish-Summers and Schmidt-Holsapple), two equations developed by the Apollo project (Rockwell and Johnson Space Center (JSC), and one recently revised from JSC (Cour-Palais). They were derived from test results, with velocities ranging up to 8 km/s. Microsoft Excel software was used to construct a spreadsheet to calculate the diameters and masses of projectiles for various velocities, varying the material properties of both projectile and target for the five single plate penetration equations. The results were plotted on diameter versus velocity graphs for ballistic and spallation limits using Cricket Graph software, for velocities ranging from 2 to 15 km/s defined for the orbital debris. First, these equations were compared to each other, then each equation was compared with various aluminum projectile densities. Finally, these equations were compared with test results performed at JSC for the Marshall Space Flight Center. These equations predict a wide variety of projectile diameters at a given velocity. Thus, it is very difficult to choose the 'right' prediction equation. The thickness of a single plate could have a large variation by choosing a different penetration equation. Even though all five equations are empirically developed with various materials, especially for aluminum alloys, one cannot be confident in the shield design with the predictions obtained by the penetration equations without verifying by tests.

  15. Penetration and Cutting Effects of Lead-Sheathed Flexible Linear Shaped Charges and Explosive-Filled Linear Shaped-Charge Containers (Mark 7 Mods 1 through 8 and Mark 8 Mod 2)

    DTIC Science & Technology

    1978-11-01

    Point6 penetration (in.) 391 7.366 8992 8814 9.195 3.890 10.211 8.966 (0 290) (0 354) (0.347) (0 362) (0.365) (0.402) (0 353) 392 9 322 9.169 7.723 8...10.008 8712 8941 8.407 8814 (0 330) 10.331) (0397) (0.343) (0352) (0.331) (0347) 423 8 611 10820 10.033 10.262 9423 6.375 9500 (0.399) (0.426) (0.395

  16. Isolation of Inositol Hexaphosphate (IHP)-Degrading Bacteria from Arbuscular Mycorrhizal Fungal Hyphal Compartments Using a Modified Baiting Method Involving Alginate Beads Containing IHP

    PubMed Central

    Hara, Shintaro; Saito, Masanori

    2016-01-01

    Phytate (inositol hexaphosphate; IHP)-degrading microbes have been suggested to contribute to arbuscular mycorrhizal fungi (AMF)-mediated P transfer from IHP to plants; however, no IHP degrader involved in AMF-mediated P transfer has been isolated to date. We herein report the isolation of IHP-degrading bacteria using a modified baiting method. We applied alginate beads as carriers of IHP powder, and used them as recoverable IHP in the AM fungal compartment of plant cultivation experiments. P transfer from IHP in alginate beads via AMF was confirmed, and extracted DNA from alginate beads was analyzed by denaturing gradient gel electrophoresis targeting the 16S rRNA gene and a clone library method for the beta-propeller phytase (BPP) gene. The diversities of the 16S rRNA and BPP genes of microbes growing on IHP beads were simple and those of Sphingomonas spp. and Caulobacter spp. dominated. A total of 187 IHP-utilizing bacteria were isolated and identified, and they were consistent with the results of DNA analysis. Furthermore, some isolated Sphingomonas spp. and Caulobacter sp. showed IHP-degrading activity. Therefore, we successfully isolated dominant IHP-degrading bacteria from IHP in an AMF hyphal compartment. These strains may contribute to P transfer from IHP via AMF. PMID:27383681

  17. Promotion of in vivo degradability, vascularization and osteogenesis of calcium sulfate-based bone cements containing nanoporous lithium doping magnesium silicate.

    PubMed

    Cao, Liehu; Weng, Weizong; Chen, Xiao; Zhang, Jun; Zhou, Qirong; Cui, Jin; Zhao, Yuechao; Shin, Jung-Woog; Su, Jiacan

    2017-01-01

    Nanoporous lithium doping magnesium silicate (nl-MS) was introduced into calcium sulfate hemihydrate to prepare calcium sulfate composite (nl-MSC) bone cements. The introduction of nl-MS improved the in vitro degradability of nl-MSC cements, which could neutralize acidic degradable products of calcium sulfate and prevented the pH from dropping. The cements were implanted into the bone defects of femur bone of rabbits, and the results of histological and immunohistochemical analysis revealed that massive new bone tissue formed in the defects while the cements were degradable, indicating that the osteogenesis and degradability of the nl-MSC cements were much better than the control calcium sulfate dihydrate (CSD) cements. Furthermore, the positive expression of vascular endothelial growth factor and collagen type I for nl-MSC cements was higher than CSD, indicating that addition of nl-MS into the cements enhanced vascularization and osteogenic differentiation. The results suggested that the nl-MSC cements with good biocompatibility and degradability could promote vascularization and osteogenesis, and had great potential to treat bone defects.

  18. Promotion of in vivo degradability, vascularization and osteogenesis of calcium sulfate-based bone cements containing nanoporous lithium doping magnesium silicate

    PubMed Central

    Cao, Liehu; Weng, Weizong; Chen, Xiao; Zhang, Jun; Zhou, Qirong; Cui, Jin; Zhao, Yuechao; Shin, Jung-Woog; Su, Jiacan

    2017-01-01

    Nanoporous lithium doping magnesium silicate (nl-MS) was introduced into calcium sulfate hemihydrate to prepare calcium sulfate composite (nl-MSC) bone cements. The introduction of nl-MS improved the in vitro degradability of nl-MSC cements, which could neutralize acidic degradable products of calcium sulfate and prevented the pH from dropping. The cements were implanted into the bone defects of femur bone of rabbits, and the results of histological and immunohistochemical analysis revealed that massive new bone tissue formed in the defects while the cements were degradable, indicating that the osteogenesis and degradability of the nl-MSC cements were much better than the control calcium sulfate dihydrate (CSD) cements. Furthermore, the positive expression of vascular endothelial growth factor and collagen type I for nl-MSC cements was higher than CSD, indicating that addition of nl-MS into the cements enhanced vascularization and osteogenic differentiation. The results suggested that the nl-MSC cements with good biocompatibility and degradability could promote vascularization and osteogenesis, and had great potential to treat bone defects. PMID:28260883

  19. Electrochemical degradation of m-cresol using porous carbon-nanotube-containing cathode and Ti/SnO2-Sb2O5-IrO2 anode: kinetics, byproducts and biodegradability.

    PubMed

    Chu, Yanyang; Zhang, Dongmei; Liu, Lei; Qian, Yi; Li, Lingling

    2013-05-15

    The degradation of m-cresol solution was studied using an electrochemical oxidation system with Ti/SnO2-Sb2O5-IrO2 anode for anodic oxidation and porous carbon-nanotube-containing cathode for H2O2 electrogeneration along with Fe(3+) reduction. Organic pollutants were oxidized by hydroxyl radical (OH) formed simultaneously in the medium from electro-Fenton reaction in the presence of Fe(2+) and at the anode surface from water oxidation. The porous cathode made of graphite, carbon nanotube (CNT) and polytetrafluoroethene (PTFE) exhibited a higher catalytic activity toward O2 reduction producing H2O2 and Fe(3+) reduction for Fe(2+) regeneration, favoring organics degradation by electro-Fenton oxidation. The degradation kinetics results revealed that the reaction of m-cresol cleavage with hydroxyl radicals could be described by pseudo first-order kinetics. The progress of organics mineralization demonstrated some byproducts were formed during m-cresol degradation. Based on the byproducts identified by GC-MS and HPLC, the sequential process of m-cresol degradation was proposed. Furthermore, the aerobic biological treatment showed that the electrochemical treatment was able to evidently enhance the biodegradability of m-cresol solution. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Penetrating craniofacial arrow injury.

    PubMed

    Jain, Dk; Aggarwal, Gaurav; Lubana, Ps; Moses, Sonia

    2010-01-01

    Arrow injuries are an extinct form of injury in most parts of the developed world, but are still seen, albeit infrequently in developing countries. Reports of penetrating injuries of the craniofacial region secondary to projectiles are few and far between. The morbidity-free outcome of surgical removal, in case of penetrating arrow injuries, despite the delay in presentation and, moreover, in the emergency surgical practice, are the salient points to be remembered whilst managing such cases, for 'what the mind knows is what the eyes see and what the eyes see is what can be practiced'. We report the case of a patient who was attacked by a projectile fired from a crossbow. Immediate surgery under general anesthesia was required to remove the arrow, with utmost care to avoid any neurovascular compromise to the facial nerve, as well as minimize postoperative complications such as otitis media and subsequent meningitis.

  1. Cognitive Penetration and Attention

    PubMed Central

    Gross, Steven

    2017-01-01

    Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. PMID:28275358

  2. Penetration Mechanics of Composites

    DTIC Science & Technology

    1992-04-01

    distribution for tensile strength of hollow virgin filaments, based on 128 tests (source: Owens / Corning Fiberglas Corp). 14 1.2 Schematic of split Hopkinson...These were supplied by Owens / Corning Fiberglas Corporation, Granville, Ohio in two forms: 463AA750 (750 yd/lb) roving tow and G150 (1500 yd/lb...penetration of 12.7-mm thick (25-ply) GRP. Targets were fabricated by Owens Corning Fiberglas (OCF) by a licensed process designated HJ1. This complies

  3. Antibody tumor penetration

    PubMed Central

    Thurber, Greg M.; Schmidt, Michael M.; Wittrup, K. Dane

    2009-01-01

    Antibodies have proven to be effective agents in cancer imaging and therapy. One of the major challenges still facing the field is the heterogeneous distribution of these agents in tumors when administered systemically. Large regions of untargeted cells can therefore escape therapy and potentially select for more resistant cells. We present here a summary of theoretical and experimental approaches to analyze and improve antibody penetration in tumor tissue. PMID:18541331

  4. Prediction of alumina penetration

    SciTech Connect

    Mandell, D A

    1993-02-01

    The MESA hydrocode was used to predict two-dimensional tests of L/D 10 and L/D 15 tungsten rods impacting AD 90 alumina with a steel backing. The residual penetration into the steel is the measured quantity in these experiments conducted at the Southwest Research Institute (SWR). The interface velocity as a function of time between an alumina target and a lithium fluoride window, impacted by an alumina disk at velocities between 544 m/s and 2329 m/s, was also predicted. These one-dimensional flyer plate experiments were conducted at Sandia National Laboratories using Coors AD 995 alumina. The material strength and fracture models are important in the prediction of ceramic experiments. The models used in these predictions are discussed. The penetrations in the two-dimensional tests were predicted to 11.4 percent or better. In five of the six experiments, the predicted penetration depth was deeper than the measured value. This trend is expected since the calculation is based on ideal conditions. The results show that good agreement between the 1-D flyer plate data and the MESA predictions exists at the lower impact velocities, but the maximum velocity is overpredicted as the flyer plate velocity increases. At a flyer plate velocity of 2329 m/s the code overpredicted the data by 12.3 percent.

  5. [Penetrating abdominal injuries].

    PubMed

    Nesbakken, A; Pillgram-Larsen, J; Naess, F; Gerner, T; Solheim, K; Stadaas, J O; Gjøra, O

    1990-02-28

    We have reviewed the medical records of 111 patients treated for abdominal stab wounds during the period 1980-87. Our two hospitals serve a catchment area of about 450,000 people. Exploratory laparotomy was performed in 89 patients with suspected peritoneal penetration. In 16 patients the laparotomy was negative, and in 15 patients only minor injuries were noted. There were no serious complications in these 31 patients. Twenty-seven patients had thoracic wounds below the fourth intercostal space, 15 with intraabdominal injuries. The most common injuries were lacerations of the liver, the small bowel and the diaphragm. The mortality in the series was 2%. Stab wounds are infrequent in Norway, and most surgeons have limited experience of such injuries. We discuss whether to employ immediate exploratory laparotomy or selective management when the peritoneum has been penetrated. When there is no evidence of evisceration or omental protrusion, local exploration of the wound should be performed in order to confirm or exclude peritoneal penetration. Injury to the diaphragm and intraabdominal viscera should always be suspected in thoracic stab wounds below the fourth intercostal space.

  6. Mars penetrator: Subsurface science mission

    NASA Technical Reports Server (NTRS)

    Lumpkin, C. K.

    1974-01-01

    A penetrator system to emplace subsurface science on the planet Mars is described. The need for subsurface science is discussed, and the technologies for achieving successful atmospheric entry, Mars penetration, and data retrieval are presented.

  7. Chemical pathways of peptide degradation. X: effect of metal-catalyzed oxidation on the solution structure of a histidine-containing peptide fragment of human relaxin.

    PubMed

    Khossravi, M; Borchardt, R T

    2000-07-01

    To elucidate the major degradation products of the metal-catalyzed oxidation of (cyclo S-S) AcCys-Ala-X-Val-Gly-CysNH2 (X = His, cyclic-His peptide), which is a fragment of the protein relaxin, and the effect of this oxidation on its solution structure. The cyclic-His peptide and its potential oxidative degradation products, cyclic-Asp peptide (X = Asp) and cyclic-Asn peptide (X = Asn), were prepared by using solid phase peptide synthesis and purified by preparative HPLC. The degradation of the cyclic-His peptide was investigated at pH 5.3 and 7.4 in an ascorbate/cupric chloride/oxygen [ascorbate/Cu(II)/O2] system in the absence or presence of catalase (CAT), superoxide dismutase (SOD), isopropanol, and thiourea. The oxidation of the cyclic-His peptide was also studied in the presence of hydrogen peroxide (H2O2). All reactions were monitored by reversed-phase HPLC. The main degradation product of the cyclic-His peptide formed at pH 7.4 in the presence of ascorbate/Cu(II)/O2 was isolated by preparative HPLC and identified by 1H NMR and electrospray mass spectrometry. The complexation of Cu(II) with the cyclic-His peptide was determined with 1H NMR. The solution structure of the cyclic-His peptide in the presence and absence of Cu(II) at pH 5.3 and 7.4 and the solution structure of the main degradation product were determined using circular dichroism (CD). CAT and thiourea were effective in stabilizing the cyclic-His peptide to oxidation by ascorbate/Cu(II)/O2, while SOD and isopropanol were ineffective. Cyclic-Asp and cyclic-Asn peptides were not observed as degradation products of the cyclic-His peptide oxidized at pH 5.3 and 7.4 in an ascorbate/Cu(II)/O2 system. The main degradation product formed at pH 7.4 was the cyclic 2-oxo-His peptide (X = 2-oxo-His). At pH 5.3, numerous degradation products were formed in low yields, including the cyclic 2-oxo-His peptide. The cyclic 2-oxo-His peptide appeared to have a different secondary structure than did the cyclic

  8. Degradation of concrete-based barriers by Mg-containing brines: From laboratory experiments via reactive transport modelling to overall safety analysis in repository scale

    NASA Astrophysics Data System (ADS)

    Niemeyer, Matthias; Wilhelm, Stefan; Hagemann, Sven; Xie, Mingliang; Wollrath, Jürgen; Preuss, Jürgen

    2010-05-01

    The Morsleben nuclear waste repository (ERAM) for low- and intermediate-level radioactive waste is located in an old rock salt and potash mine in Northern Germany. From 1971 to 1998, approximately 36 800 m3 of waste have been disposed of. Now, waste disposal is finished, and the repository has to be backfilled and sealed. The closure concept is based on extensive backfilling of the salt mine with an inexpensive concrete mixture. The major disposal areas, containing most of the waste, will be isolated from the rest of the mine building by sealing the connecting access tunnels. The good geological situation (an intact cap rock with very small flow rates) provides an excellent basic condition for a safe repository. However, the access of water to the remaining parts of the mine cannot be excluded. The brines that are formed in contact with potash salts will contain Mg in a concentration that depends on various factors and cannot be predicted. For backfill and closure of the repository, no common material chemically stable against brines of all possible compositions is available. Salt concrete has a low permeability but is corroded by brines containing Mg, whilst concrete based on Sorel phases is decomposed if the Mg-content of the brines is too low. In each of these alternatives, corrosion results in a strong increase of permeability and a loss of the mechanical integrity of the material. However, for large hydraulic seals the flow of corroding brines is limited because of the high hydraulic resistance of the barrier. Thus, the barriers will persist for a long time in spite of the chemical incompatibility of building material and brine. For the planning of the backfill and closure measures as well as for the license application procedure it is crucial to demonstrate that the seals of the major disposal areas will keep their function for a sufficient long time. This lifetime depends among others on the corrosion capacity of the brine to the building material, on the

  9. Analysis of the xplAB-Containing Gene Cluster Involved in the Bacterial Degradation of the Explosive Hexahydro-1,3,5-Trinitro-1,3,5-Triazine

    PubMed Central

    Chong, Chun Shiong; Sabir, Dana Khdr; Lorenz, Astrid; Bontemps, Cyril; Andeer, Peter; Stahl, David A.; Strand, Stuart E.; Rylott, Elizabeth L.

    2014-01-01

    Repeated use of the explosive compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) on military land has resulted in significant soil and groundwater pollution. Rates of degradation of RDX in the environment are low, and accumulated RDX, which the U.S. Environmental Protection Agency has determined is a possible human carcinogen, is now threatening drinking water supplies. RDX-degrading microorganisms have been isolated from RDX-contaminated land; however, despite the presence of these species in contaminated soils, RDX pollution persists. To further understand this problem, we studied RDX-degrading species belonging to four different genera (Rhodococcus, Microbacterium, Gordonia, and Williamsia) isolated from geographically distinct locations and established that the xplA and xplB (xplAB) genes, which encode a cytochrome P450 and a flavodoxin redox partner, respectively, are nearly identical in all these species. Together, the xplAB system catalyzes the reductive denitration of RDX and subsequent ring cleavage under aerobic and anaerobic conditions. In addition to xplAB, the Rhodococcus species studied here share a 14-kb region flanking xplAB; thus, it appears likely that the RDX-metabolizing ability was transferred as a genomic island within a transposable element. The conservation and transfer of xplAB-flanking genes suggest a role in RDX metabolism. We therefore independently knocked out genes within this cluster in the RDX-degrading species Rhodococcus rhodochrous 11Y. Analysis of the resulting mutants revealed that XplA is essential for RDX degradation and that XplB is not the sole contributor of reducing equivalents to XplA. While XplA expression is induced under nitrogen-limiting conditions and further enhanced by the presence of RDX, MarR is not regulated by RDX. PMID:25128343

  10. Study of light water reactor containments under important severe accident conditions

    SciTech Connect

    Hofmayer, C.H.; Pratt, W.T.; Bagchi, G.; Noonan, V.S.

    1985-01-01

    The US Nuclear Regulatory Commission has sponsored studies to develop a ''LEAKAGE-BEFORE-FAILURE'' model for use in severe accident risk assessments to provide a means of accounting for significant containment leakage prior to reaching the containment threshold pressure. Six containment types have been studied (large dry, subatmospheric, ice condenser, Mark I, II, and III). Potential leak paths through major containment penetration assemblies were investigated and upper-bound estimates of leak areas established. These leak areas may result from increasing internal pressure and degradation of nonmetallic seal materials due to severe accident conditions. This paper describes the approach and summarizes the results and conclusions of this study.

  11. Degradation and biological properties of Ca-P contained micro-arc oxidation self-sealing coating on pure magnesium for bone fixation

    PubMed Central

    Wang, Weidan; Wan, Peng; Liu, Chen; Tan, Lili; Li, Weirong; Li, Lugee; Yang, Ke

    2015-01-01

    Poor corrosion resistance is one of the main disadvantages for biodegradable magnesium-based metals, especially applied for bone fixation, where there is a high demand of bio-mechanical strength and stability. Surface coating has been proved as an effective method to control the in vivo degradation. In this study a Ca-P self-sealing micro-arc oxidation (MAO) coating was studied to verify its efficacy and biological properties by in vitro and in vivo tests. It was found that the MAO coating could effectively retard the degradation according to immersion and electrochemical tests as well as 3D reconstruction by X-ray tomography after implantation. The MAO coating exhibited no toxicity and could stimulate the new bone formation. Therefore, the Ca-P self-sealing MAO coating could be a potential candidate for application of biodegradable Mg-based implant in bone fixations. PMID:26816635

  12. Penetrating neck traumas

    PubMed Central

    Kaczmarski, Jacek; Brzeziński, Daniel; Cieślik-Wolski, Bartosz; Kozak, Józef

    2014-01-01

    Aim of the study Aim of the study is to present our own experiences in the treatment of people suffering from penetrating neck traumas. Material and methods In the years 1996-2012, 10 patients with penetrating neck traumas were treated, including 3 women and 7 men. The patients’ age ranged from 16 to 55 (the average age being 40.7 years). In 9 cases the wound was caused by cutting or stabbing, while in one case it was inflicted by a gunshot. In 8 patients it was a single cut wound, while one patient suffered from 34 stab wounds to the neck, chest and stomach. Two cut wounds resulted from a suicide attempt. The remaining injuries were the result of a crime. Results All patients underwent immediate surgery, which involved revision of the neck wounds in 8 cases, one longitudinal sternotomy and one left-sided thoracotomy. The indications for surgery included increased subcutaneous emphysema in 5 patients, bleeding from the wound in 3 patients, and mediastinal hematoma in 2 patients. The damage assessed intraoperatively included tracheal damage in 6 patients, damage to carotid vessels in 3 patients, larynx in 2 patients, thoracic vessels in 2 patients, oesophagus in 1 patient and thyroid gland in 1 patient. In 9 patients, the treatment yielded positive results. The patient with a gunshot wound died during the surgery due to massive bleeding from the aorta. Conclusions In patients with penetrating neck wounds, early and rapid diagnostics allows one to determine the indications for surgery and prevent serious fatal complications. PMID:26336390

  13. Comparison of the protection effectiveness of acrylic polyurethane coatings containing bark extracts on three heat-treated North American wood species: Surface degradation

    NASA Astrophysics Data System (ADS)

    Kocaefe, Duygu; Saha, Sudeshna

    2012-04-01

    High temperature heat-treatment of wood is a very valuable technique which improves many properties (biological durability, dimensional stability, thermal insulating characteristics) of natural wood. Also, it changes the natural color of wood to a very attractive dark brown color. Unfortunately, this color is not stable if left unprotected in external environment and turns to gray or white depending on the wood species. To overcome this problem, acrylic polyurethane coatings are applied on heat-treated wood to delay surface degradations (color change, loss of gloss, and chemical modifications) during aging. The acrylic polyurethane coatings which have high resistance against aging are further modified by adding bark extracts and/or lignin stabilizer to enhance their effectiveness in preventing the wood aging behavior. The aging characteristic of this coating is compared with acrylic polyurethane combined with commercially available organic UV stabilizers. In this study, their performance on three heat-treated North American wood species (jack pine, quaking aspen and white birch) are compared under accelerated aging conditions. Both the color change data and visual assessment indicate improvement in protective characteristic of acrylic polyurethane when bark extracts and lignin stabilizer are used in place of commercially available UV stabilizer. The results showed that although acrylic polyurethane with bark extracts and lignin stabilizer was more efficient compared to acrylic polyurethane with organic UV stabilizers in protecting heat-treated jack pine, it failed to protect heat-treated aspen and birch effectively after 672 h of accelerated aging. This degradation was not due to the coating adhesion loss or coating degradation during accelerated aging; rather, it was due to the significant degradation of heat-treated aspen and birch surface beneath this coating. The XPS results revealed formation of carbonyl photoproducts after aging on the coated surfaces and

  14. Penetrating thoracic trauma.

    PubMed

    Bastos, Renata; Baisden, Clinton E; Harker, Lori; Calhoon, John H

    2008-01-01

    The initial approach to penetrating thoracic trauma is directed towards the pathophysiologic syndrome upon presentation. Most patients are successfully treated with drainage tubes. The unstable patient may necessitate thoracotomy at the emergency room to drain cardiac tamponade, provide cardiac massage and control bleeding. The guidelines for this procedure are reviewed. Need for further work-up of potential injuries to other mediastinal organs is frequently screened by computerized tomography. Surgery might still be needed, on a less emergent basis, in order to repair injuries to the trachea/esophagus, retained hemothorax, or to rule out diaphragmatic injury. Laparoscopic and thoracoscopic procedures may be used in specific situations.

  15. Penetrating Fire Extinguisher

    NASA Technical Reports Server (NTRS)

    1985-01-01

    When Feecon Corporation, a manufacturer of fire protection systems, needed a piercing nozzle for larger aircraft, they were assisted by Kennedy Space Center who provided the company with a fire extinguisher with a hard pointed tip that had been developed in case of an orbiter crash landing. The nozzle can penetrate metal skins of aircraft, trains, etc. Feecon obtained a license and now markets its cobra ram piercing nozzle to airport firefighters. Its primary advantage is that the nozzle can be held in one spot during repeated blows of the ram. *This product has been discontinued and is no longer commercially available.

  16. Plant cell walls: Protecting the barrier from degradation by microbial enzymes.

    PubMed

    Lagaert, Stijn; Beliën, Tim; Volckaert, Guido

    2009-12-01

    Plant cell walls are predominantly composed of polysaccharides, which are connected in a strong, yet resilient network. They determine the size and shape of plant cells and form the interface between the cell and its often hostile environment. To penetrate the cell wall and thus infect plants, most phytopathogens secrete numerous cell wall degrading enzymes. Conversely, as a first line of defense, plant cell walls contain an array of inhibitors of these enzymes. Scientific knowledge on these inhibitors significantly progressed in the past years and this review is meant to give a comprehensive overview of plant inhibitors against microbial cell wall degrading enzymes and their role in plant protection.

  17. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  18. Overview - Hard Rock Penetration

    SciTech Connect

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  19. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  20. Sand Penetration Experiments

    NASA Astrophysics Data System (ADS)

    Bless, Stephan; Berry, Don; Lawhorn, William

    2009-06-01

    In an experimental program, steel bullets and short cylinders, and tungsten alloy rods were shot into dry silica sand at 600 to 1100 m/s. The rods included finsets that were designed for aerodynamic stabilization. The fins also apparently provided trajectory stabilization within the sand as well. Time-of-arrival screens allowed measurement of velocity. Analysis of those data indicated that drag coefficients increased as projectiles slowed down. Comparison with previous data indicates there was a slight increase in drag coefficient of rods over expected values for unfinned rods; however, the net result was penetration normalized by length was as high as 40, depending on nose shape. It was found that when the velocity exceeded about 80 m/s (which is close to the speed of sound in sand) sand particles were broken down into their constituent grains, resulting in a decrease in size by about 1000. Normalized penetration is expected to scale as kinetic energy per unit area, and it was significantly higher for the rods than for the other projectiles. This is attributed to stabilization from interaction of the fins with the cavity wall.

  1. Penetration in GTA welding

    SciTech Connect

    Heiple, C.R.; Burgardt, P.

    1990-01-01

    The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

  2. Neurons containing Alz-50-immunoreactive granules around the cerebral infarction: evidence for the lysosomal degradation of altered tau in human brain?

    PubMed

    Ikeda, K; Akiyama, H; Arai, T; Kondo, H; Haga, C; Tsuchiya, K; Yamada, S; Murayama, S; Hori, A

    2000-04-28

    Little is known about the metabolic process of tau and tau-derived substances. Alz-50- and tau 2-immunoreactivities in intracellular granules of neurons were observed in regions surrounding infarcted foci in the human cerebral cortex. Ultrastructurally, these granules in the fresh infarcted region exhibited primary lysosome-like structures, while those in old infarctions were lipofuscin. These findings indicate that tau is metabolized within lysosomes in neurons damaged by ischemic injury in human cortical penumbra. Alz-50-positive granules were more prominent in fresh infarction than in old infarction. After undergoing degradation and modification, altered tau might remain, at least partially, in secondary lysosomes.

  3. Fluid transport container

    DOEpatents

    DeRoos, Bradley G.; Downing, Jr., John P.; Neal, Michael P.

    1995-01-01

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitment for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container.

  4. Fluid transport container

    DOEpatents

    DeRoos, B.G.; Downing, J.P. Jr.; Neal, M.P.

    1995-11-14

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitting for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container. 13 figs.

  5. Endolysosomal Degradation of Allergenic Ole e 1-Like Proteins: Analysis of Proteolytic Cleavage Sites Revealing T Cell Epitope-Containing Peptides.

    PubMed

    Wildner, Sabrina; Elsässer, Brigitta; Stemeseder, Teresa; Briza, Peter; Soh, Wai Tuck; Villalba, Mayte; Lidholm, Jonas; Brandstetter, Hans; Gadermaier, Gabriele

    2017-08-16

    Knowledge of the susceptibility of proteins to endolysosomal proteases provides valuable information on immunogenicity. Though Ole e 1-like proteins are considered relevant allergens, little is known about their immunogenic properties and T cell epitopes. Thus, six representative molecules, i.e., Ole e 1, Fra e 1, Sal k 5, Che a 1, Phl p 11 and Pla l 1, were investigated. Endolysosomal degradation and peptide generation were simulated using microsomal fractions of JAWS II dendritic cells. Kinetics and peptide patterns were evaluated by gel electrophoresis and mass spectrometry. In silico MHC (major histocompatibility complex) class II binding prediction was performed with ProPred. Cleavage sites were assigned to the primary and secondary structure, and in silico docking experiments between the protease cathepsin S and Ole e 1 were performed. Different kinetics during endolysosomal degradation were observed while similar peptide profiles especially at the C-termini were detected. Typically, the identified peptide clusters comprised the previously-reported T cell epitopes of Ole e 1, consistent with an in silico analysis of the T cell epitopes. The results emphasize the importance of the fold on allergen processing, as also reflected by conserved cleavage sites located within the large flexible loop. In silico docking and mass spectrometry results suggest that one of the first Ole e 1 cleavages might occur at positions 107-108. Our results provided kinetic and structural information on endolysosomal processing of Ole e 1-like proteins.

  6. Simultaneous photocatalytic and microbial degradation of dye-containing wastewater by a novel g-C3N4-P25/photosynthetic bacteria composite.

    PubMed

    Zhang, Xinying; Wu, Yan; Xiao, Gao; Tang, Zhenping; Wang, Meiyin; Liu, Fuchang; Zhu, Xuefeng

    2017-01-01

    Azo dyes are very resistant to light-induced fading and biodegradation. Existing advanced oxidative pre-treatment methods based on the generation of non-selective radicals cannot efficiently remove these dyes from wastewater streams, and post-treatment oxidative dye removal is problematic because it may leave many byproducts with unknown toxicity profiles in the outgoing water, or cause expensive complete mineralization. These problems could potentially be overcome by combining photocatalysis and biodegradation. A novel visible-light-responsive hybrid dye removal agent featuring both photocatalysts (g-C3N4-P25) and photosynthetic bacteria encapsulated in calcium alginate beads was prepared by self-assembly. This system achieved a removal efficiency of 94% for the dye reactive brilliant red X-3b and also reduced the COD of synthetic wastewater samples by 84.7%, successfully decolorized synthetic dye-contaminated wastewater and reduced its COD, demonstrating the advantages of combining photocatalysis and biocatalysis for wastewater purification. The composite apparently degrades X-3b by initially converting the dye into aniline and phenol derivatives whose aryl moieties are then attacked by free radicals to form alkyl derivatives, preventing the accumulation of aromatic hydrocarbons that might suppress microbial activity. These alkyl intermediates are finally degraded by the photosynthetic bacteria.

  7. Simultaneous photocatalytic and microbial degradation of dye-containing wastewater by a novel g-C3N4-P25/photosynthetic bacteria composite

    PubMed Central

    Zhang, Xinying; Wu, Yan; Xiao, Gao; Tang, Zhenping; Wang, Meiyin; Liu, Fuchang; Zhu, Xuefeng

    2017-01-01

    Azo dyes are very resistant to light-induced fading and biodegradation. Existing advanced oxidative pre-treatment methods based on the generation of non-selective radicals cannot efficiently remove these dyes from wastewater streams, and post-treatment oxidative dye removal is problematic because it may leave many byproducts with unknown toxicity profiles in the outgoing water, or cause expensive complete mineralization. These problems could potentially be overcome by combining photocatalysis and biodegradation. A novel visible-light-responsive hybrid dye removal agent featuring both photocatalysts (g-C3N4-P25) and photosynthetic bacteria encapsulated in calcium alginate beads was prepared by self-assembly. This system achieved a removal efficiency of 94% for the dye reactive brilliant red X-3b and also reduced the COD of synthetic wastewater samples by 84.7%, successfully decolorized synthetic dye-contaminated wastewater and reduced its COD, demonstrating the advantages of combining photocatalysis and biocatalysis for wastewater purification. The composite apparently degrades X-3b by initially converting the dye into aniline and phenol derivatives whose aryl moieties are then attacked by free radicals to form alkyl derivatives, preventing the accumulation of aromatic hydrocarbons that might suppress microbial activity. These alkyl intermediates are finally degraded by the photosynthetic bacteria. PMID:28273118

  8. Water penetration study

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.

    1973-01-01

    Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.

  9. Different failure modes for V-containing and V-free AB2 metal hydride alloys

    NASA Astrophysics Data System (ADS)

    Young, K.; Wong, D. F.; Yasuoka, S.; Ishida, J.; Nei, J.; Koch, J.

    2014-04-01

    Failure modes of a V-containing and a V-free AB2 Laves phase-based metal hydride alloy were studied by the combination of X-ray diffractometer, scanning electron microscope, X-ray energy dispersive spectroscopy, inductively coupled plasma, Soxhlet extraction, and magnetic susceptibility measurement. Cells with the V-containing alloy exhibited less capacity degradation up until venting occurred in the cells, after which the capacity rapidly degraded. Cells with the V-free alloy remained linear in capacity degradation throughout the cycle life test. The failure mechanism for the V-containing alloy is related to the formation of an oxide layer that penetrates deeper into the alloy particles due to high V leaching and impedes gas recombination, while the failure mechanism for the V-free alloy is related to the continuous pulverization of the main AB2 phase.

  10. Penetration of amalgam constituents into dentine.

    PubMed

    Scholtanus, Johannes D; Ozcan, Mutlu; Huysmans, Marie-Charlotte D N J M

    2009-05-01

    Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. It is questioned whether penetration of metals into dentine affects the dentine as a substrate for adhesive procedures. This study has been performed to clarify the origin of dark discoloration of dentine by metals from amalgam with special regards to corrosion products. A review of the literature has been performed using Medline database. As keywords dentine and amalgam, subsequently combined with penetration, interface, crevice, interaction, corrosion, were used. This was followed up by extensive hand search using reference lists of relevant articles. Data in the literature have been gathered from extracted amalgam filled teeth and from artificially aged amalgam filled teeth. Corrosion studies have been performed in vivo aged teeth as well as in vitro. Sn is the main element, followed by Zn and Cu, that is consistently found in dentine underneath amalgam, as well as in amalgam corrosion products and in marginal seal deposits. Penetration of elements from amalgam has only been observed in discolored and in demineralised dentine. Darkly discolored dentine as found underneath amalgam restorations contains amalgam corrosion products and is demineralised. Therefore it must be considered a different substrate for clinical procedures than sound dentine.

  11. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, Phillip W.; Stampfer, Joseph F.; Bradley, Orvil D.

    1999-01-01

    A universal penetration test apparatus for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material.

  12. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, P.W.; Stampfer, J.F.; Bradley, O.D.

    1999-02-02

    A universal penetration test apparatus is described for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material. 23 figs.

  13. Corrosion assessment of dry fuel storage containers

    SciTech Connect

    Graves, C.E.

    1994-09-01

    The structural stability as a function of expected corrosion degradation of 75 dry fuel storage containers located in the 200 Area Low-Level Waste Burial Grounds was evaluated. These containers include 22 concrete burial containers, 13 55-gal (208-l) drums, and 40 Experimental Breeder Reactor II (EBR-II) transport/storage casks. All containers are buried beneath at least 48 in. of soil and a heavy plastic tarp with the exception of 35 of the EBR-II casks which are exposed to atmosphere. A literature review revealed that little general corrosion is expected and pitting corrosion of the carbon steel used as the exterior shell for all containers (with the exception of the concrete containers) will occur at a maximum rate of 3.5 mil/yr. Penetration from pitting of the exterior shell of the 208-l drums and EBR-II casks is calculated to occur after 18 and 71 years of burial, respectively. The internal construction beneath the shell would be expected to preclude containment breach, however, for the drums and casks. The estimates for structural failure of the external shells, large-scale shell deterioration due to corrosion, are considerably longer, 39 and 150 years respectively for the drums and casks. The concrete burial containers are expected to withstand a service life of 50 years.

  14. Skin Penetration Enhancement by Natural Oils for Dihydroquercetin Delivery.

    PubMed

    Čižinauskas, Vytis; Elie, Nicolas; Brunelle, Alain; Briedis, Vitalis

    2017-09-12

    Natural oils are commonly used in topical pharmaceutical formulations as emulsifiers, stabilizers or solubility enhancers. They are presented as safe and inert components, mainly used for formulation purposes. It is confirmed that natural oils can affect the skin penetration of various substances. Fatty acids are mainly responsible for this effect. Current understanding lacks reliable scientific data on penetration of natural oils into the skin and their skin penetration enhancement potential. In the current study, fatty acid content analysis was used to determine the principal fatty acids in soybean, olive, avocado, sea-buckthorn pulp, raspberry seed and coconut oils. Time of flight secondary ion mass spectrometry bioimaging was used to determine the distribution of these fatty acids in human skin ex vivo after application of the oils. Skin penetration enhancement ratios were determined for a perspective antioxidant compound dihydroquercetin. The results demonstrated skin penetration of fatty acids from all oils tested. Only soybean and olive oils significantly increased the skin distribution of dihydroquercetin and can be used as skin penetration enhancers. However, no correlation can be determined between the fatty acids' composition and skin penetration enhancement using currently available methodological approaches. This indicates that potential chemical penetration enhancement should be evaluated during formulation of topically applied products containing natural oils.

  15. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  16. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  17. Degradation of a textile dye, Rhodamine 6G (Rh6G), by heterogeneous sonophotoFenton process in the presence of Fe-containing TiO2 catalysts.

    PubMed

    Demir, Nazlı; Gündüz, Gönül; Dükkancı, Meral

    2015-03-01

    In this study, degradation of Rhodamine 6G (Rh6G) was investigated with ultrasound-assisted heterogeneous photoFenton process by iron-containing TiO2 catalysts. The catalysts were prepared by incipient wetness impregnation method and characterized by XRD, SEM, FT-IR, nitrogen adsorption, and ICP-AES measurements. Almost complete color removal (99.9 %) was achieved after a reaction time of 90 min while chemical oxygen demand (COD) could be removed by 24 % only with the 1 wt% iron-containing TiO2 catalyst. Initial color removal after 15 min of reaction and total COD abatement after 90 min of reaction decreased with increasing calcination temperature of the catalyst from 573 to 973 K. This indicated that the catalytic activity of the catalyst depend on the percentage of anatase phase in the TiO2, which was decreased with increasing calcination temperature.

  18. Magnetically Vectored Nanocapsules for Tumor Penetration and Remotely Switchable On-Demand Drug Release

    NASA Astrophysics Data System (ADS)

    Kong, Seong Deok

    Hollow-sphere nanocapsules containing intentionally trapped magnetic nanoparticles and defined anticancer drugs provide a powerful magnetic vector under moderate gradient magnetic fields, and enable the nanocapsules to penetrate into the midst of tumors and allow a controlled on-off switchable release of the anticancer drug cargo by remotely applied Radio Frequency (RF) magnetic field. This imageable smart drug delivery system is compact because the drug molecules and magnetic nanoparticles can all be self-contained within 80~150 nm capsules. In vitro as well as in vivo results indicate that the nanocapsules are effective in reducing tumor cell growth. In Chapter 1, the concept of Drug Delivery Systems (DDSs) and the impact of nanotechnology on Drug Delivery Systems were introduced. Triggered drug release using magnetothermally-responsive nanomaterials, magnetic nanoparticles for nanomedicine, and ordered mesoporous materials in the context of Drug Delivery System were discussed. In Chapter 2, creation of remotely controllable, On-Off switchable drug release methodology was described. In this thesis work, triggerable nanocapsules which contain magnetic nanoparticles responsive to external radio frequency (RF) magnetic field have been successfully created. This is in contrast to the regular hollow nanospheres for slow passive release of drugs. The new nanocapsule material consists of bio-inert, bio-compatible or bio-degradable material that we can be selected from a variety of materials depending on specific medical applications. In Chapter 3, study and utilization of magnetic vector for guided tumor penetration was discussed. In the presence of a moderate gradient magnetic field, a powerful magnetic vector is created that allows these nanocapsules to cross cell membranes or blood-tissue barriers and penetrate into the midst of tumors, thus overcoming the well-known problem of limited access of anti-cancer drugs to cancer cells in the interior of a tumor tissue. In

  19. Top Sounder Ice Penetration

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Goemmer, S. A.; Sweeney, J. H.

    2014-12-01

    Ice draft measurements are made as part of normal operations for all US Navy submarines operating in the Arctic Ocean. The submarine ice draft data are unique in providing high resolution measurements over long transects of the ice covered ocean. The data has been used to document a multidecadal drop in ice thickness, and for validating and improving numerical sea-ice models. A submarine upward-looking sonar draft measurement is made by a sonar transducer mounted in the sail or deck of the submarine. An acoustic beam is transmitted upward through the water column, reflecting off the bottom of the sea ice and returning to the transducer. Ice thickness is estimated as the difference between the ship's depth (measured by pressure) and the acoustic range to the bottom of the ice estimated from the travel time of the sonar pulse. Digital recording systems can provide the return off the water-ice interface as well as returns that have penetrated the ice. Typically, only the first return from the ice hull is analyzed. Information regarding ice flow interstitial layers provides ice age information and may possibly be derived with the entire return signal. The approach being investigated is similar to that used in measuring bottom sediment layers and will involve measuring the echo level from the first interface, solving the reflection loss from that transmission, and employing reflection loss versus impedance mismatch to ascertain ice structure information.

  20. Electromagnetic Field Penetration Studies

    NASA Technical Reports Server (NTRS)

    Deshpande, M.D.

    2000-01-01

    A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

  1. USDC-based rapid penetrator of packed soil

    NASA Astrophysics Data System (ADS)

    Bao, X.; Bar-Cohen, Y.; Chang, Z.; Sherrit, S.; Badescu, M.; Du, S.; Song, T.; Peterson, T.

    2006-03-01

    Environment protection requires more testing and analysis tools. To detect buried chemical containers or other objects embedded in soil and avoid possible damage to them, a penetrator was developed for packed soil that requires low penetration force (the force needed to push rod probe into the soil). The design was based on the novel mechanism used by the ultrasonic/sonic driller/corer (USDC) that was developed jointly by scientists at the NDEAA lab at JPL and engineers at Cybersonics, Inc. [Bar-Cohen et al 2001, Bao et al 2003]. In the penetrator, a small free-flying mass is energized by a piezoelectric transducer and impacts a rod probe on its shoulder at frequencies of several hundred Hetz. The impacts help the probe to penetrate the packed soil with low pushing force. A large reduction of the penetration force was achieved. Preliminary tests show that the effects of the penetrator on plastic containers and other objectors are minimal. The details of the design of the prototype penetrator and the results of performance tests are presented.

  2. Penetrating Neck Trauma: Review of 192 Cases

    PubMed Central

    Mahmoodie, Mohsen; Sanei, Behnam; Moazeni-Bistgani, Mohammad; Namgar, Mohammad

    2012-01-01

    Background The neck region contains a high density of vital organ structures within a relatively small and unprotected anatomic region, making it one of the most vulnerable areas of the body for all types of injuries. Objectives In this article, we studied penetrating neck trauma cases in Alzahra Hospital over a 10-year period. Patients and Methods In this retrospective, descriptive, analytical study, penetrating neck trauma cases admitted to Alzahra Hospital between April 2000 and April 2010 were analyzed for epidemiology, mechanism of trauma, zone of trauma, therapeutic method, injuries to other organs, complications, and mortality. Results Among 192 penetrating neck injuries, the mean age at the time of injury was 25.08 ± 15.02 years. Of these cases, 96.4% occurred in men. The most common mechanisms of trauma was stab wounds (85.93%). In 56.3% of penetrating neck injuries, zone 2 was involved. Neck exploration was positive in 84.4% of cases, and 52.1% of patients underwent surgery. Vascular exploration was the most common cause of surgery (67.2% of patients). The most common surgical intervention was vein ligation (50.8% of cases). In 11.98% of cases, another organ injury occurred simultaneously, and chest injury was the most common coexisting problem (65.2%). Complications were reported in 9.3% of patients, and the need for intubation was the most common complication (5.2% of patients). Mortality rate was 1.5%. Conclusions According to the findings of this study, the most common cause of penetrating neck injuries was stab wounds, and the majority of patients were young men, therefore, preventive measures should be implemented. Because of fatal complications associated with neck injuries, we recommend early neck exploration in unstable cases or when injuries are deeper than the platysma. PMID:24719835

  3. Static penetration resistance of soils

    NASA Technical Reports Server (NTRS)

    Durgunoglu, H. T.; Mitchell, J. K.

    1973-01-01

    Model test results were used to define the failure mechanism associated with the static penetration resistance of cohesionless and low-cohesion soils. Knowledge of this mechanism has permitted the development of a new analytical method for calculating the ultimate penetration resistance which explicitly accounts for penetrometer base apex angle and roughness, soil friction angle, and the ratio of penetration depth to base width. Curves relating the bearing capacity factors to the soil friction angle are presented for failure in general shear. Strength parameters and penetrometer interaction properties of a fine sand were determined and used as the basis for prediction of the penetration resistance encountered by wedge, cone, and flat-ended penetrometers of different surface roughness using the proposed analytical method. Because of the close agreement between predicted values and values measured in laboratory tests, it appears possible to deduce in-situ soil strength parameters and their variation with depth from the results of static penetration tests.

  4. An Earth Penetrating Modeling Assessment

    SciTech Connect

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  5. An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment.

    PubMed

    Aravind, Priyadharshini; Selvaraj, Hosimin; Ferro, Sergio; Sundaram, Maruthamuthu

    2016-11-15

    A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO2-RuO2-TiO2 anodes), lead to discoloration by 92% and 89%, respectively, in 100min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144h. Based on results obtained through FT-IR and GC-MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Optimal shapes of axisymmetric bodies penetrating into soil

    NASA Astrophysics Data System (ADS)

    Kotov, V. L.; Linnik, E. Yu.; Tarasova, A. A.

    2016-09-01

    This paper presents the results of a study of the shapes of axisymmetric bodies with minimum drag and maximum depth of penetration into the plastic soils. Optimal shapes of bodies of revolution of given length and cross-sectional radius with generatrices represented by line segments are obtained by a modified method of local variations. The problem is solved using a binomial quadratic model of local interaction, including inertial and strength terms containing constant and Coulomb frictions. The drag forces and the penetration depth of cones and the obtained bodies of optimal shape are determined at different penetration velocities.

  7. Penetrating zone II neck injury by broken windshield.

    PubMed

    Ozturk, Kayhan; Keles, Bahar; Cenik, Ziya; Yaman, Huseyin

    2006-03-01

    All penetrating neck wounds are potentially dangerous and require emergency treatment because there are important vessels, nerves and organs in the neck. We present the case of a patient who had an unusual penetrating neck injury caused by a broken windshield, noticed accidentally. Because fragments of windshield glass consist of sharp material, and the neck contains vital structures, such penetrating neck injury may cause life-threatening complications. Radiological examinations should be offered before the management of all neck wounds. The risk of retained foreign bodies and related complications can be prevented by using fluoroscopy during surgical exploration of the neck.

  8. Complex of Fas-associated factor 1 (FAF1) with valosin-containing protein (VCP)-Npl4-Ufd1 and polyubiquitinated proteins promotes endoplasmic reticulum-associated degradation (ERAD).

    PubMed

    Lee, Jae-Jin; Park, Joon Kyu; Jeong, Jaeho; Jeon, Hyesung; Yoon, Jong-Bok; Kim, Eunice EunKyeong; Lee, Kong-Joo

    2013-03-08

    Fas-associated factor 1 (FAF1) is a ubiquitin receptor containing multiple ubiquitin-related domains including ubiquitin-associated (UBA), ubiquitin-like (UBL) 1, UBL2, and ubiquitin regulatory X (UBX). We previously showed that N-terminal UBA domain recognizes Lys(48)-ubiquitin linkage to recruit polyubiquitinated proteins and that a C-terminal UBX domain interacts with valosin-containing protein (VCP). This study shows that FAF1 interacts only with VCP complexed with Npl4-Ufd1 heterodimer, a requirement for the recruitment of polyubiquitinated proteins to UBA domain. Intriguingly, VCP association to C-terminal UBX domain regulates ubiquitin binding to N-terminal UBA domain without direct interaction between UBA and UBX domains. These interactions are well characterized by structural and biochemical analysis. VCP-Npl4-Ufd1 complex is known as the machinery required for endoplasmic reticulum-associated degradation. We demonstrate here that FAF1 binds to VCP-Npl4-Ufd1 complex via UBX domain and polyubiquitinated proteins via UBA domain to promote endoplasmic reticulum-associated degradation.

  9. Ultrasonic/Sonic Impacting Penetrators

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Stark, Randall A.

    2008-01-01

    Ultrasonic/sonic impacting penetrators (USIPs) are recent additions to the series of apparatuses based on ultrasonic/sonic drill corers (USDCs). A USIP enables a rod probe to penetrate packed soil or another substance of similar consistency, without need to apply a large axial force that could result in buckling of the probe or in damage to some buried objects. USIPs were conceived for use in probing and analyzing soil to depths of tens of centimeters in the vicinity of buried barrels containing toxic waste, without causing rupture of the barrels. USIPs could also be used for other purposes, including, for example, searching for pipes, barrels, or other hard objects buried in soil; and detecting land mines. USDCs and other apparatuses based on USDCs have been described in numerous previous NASA Tech Briefs articles. The ones reported previously were designed, variously, for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. To recapitulate: A USDC can be characterized as a lightweight, low-power, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. As shown in the figure, a basic USDC includes a piezoelectric stack, a backing and a horn connected to the stack, a free mass (free in the sense that it can slide axially a short distance between the horn and the shoulder of tool bit), and a tool bit, i.e., probe for USIP. The piezoelectric stack is driven at the resonance frequency of the stack/horn/backing assembly to create ultrasonic vibrations that are mechanically amplified by the horn. To prevent fracture during operation, the piezoelectric stack is held in compression by a bolt. The bouncing of the free mass between the horn and the tool bit at sonic frequencies generates hammering actions to the bit that are more effective for drilling than is the microhammering action of ultrasonic vibrations in ordinary ultrasonic drills. The hammering actions

  10. 4-hydroxybenzoyl coenzyme A reductase (dehydroxylating) is required for anaerobic degradation of 4-hydroxybenzoate by Rhodopseudomonas palustris and shares features with molybdenum-containing hydroxylases.

    PubMed

    Gibson, J; Dispensa, M; Harwood, C S

    1997-02-01

    The anaerobic degradation of 4-hydroxybenzoate is initiated by the formation of 4-hydroxybenzoyl coenzyme A, with the next step proposed to be a dehydroxylation to benzoyl coenzyme A, the starting compound for a central pathway of aromatic compound ring reduction and cleavage. Three open reading frames, divergently transcribed from the 4-hydroxybenzoate coenzyme A ligase gene, hbaA, were identified and sequenced from the phototrophic bacterium Rhodopseudomonas palustris. These genes, named hbaBCD, specify polypeptides of 17.5, 82.6, and 34.5 kDa, respectively. The deduced amino acid sequences show considerable similarities to a group of hydroxylating enzymes involved in CO, xanthine, and nicotine metabolism that have conserved binding sites for [2Fe-2S] clusters and a molybdenum cofactor. Cassette disruption of the hbaB gene yielded a mutant that was unable to grow anaerobically on 4-hydroxybenzoate but grew normally on benzoate. The hbaB mutant cells did not accumulate [14C]benzoyl coenzyme A during short-term uptake of [14C]4-hydroxybenzoate, but benzoyl coenzyme A was the major radioactive metabolite formed by the wild type. In addition, crude extracts of the mutant failed to convert 4-hydroxybenzoyl coenzyme A to benzoyl coenzyme A. This evidence indicates that the hbaBCD genes encode the subunits of a 4-hydroxybenzoyl coenzyme A reductase (dehydroxylating). The sizes of the specified polypeptides are similar to those reported for 4-hydroxybenzoyl coenzyme A reductase isolated from the denitrifying bacterium Thauera aromatica. The amino acid consensus sequence for a molybdenum cofactor binding site is in HbaC. This cofactor appears to be an essential component because anaerobic growth of R. palustris on 4-hydroxybenzoate, but not on benzoate, was retarded unless 0.1 microM molybdate was added to the medium. Neither tungstate nor vanadate replaced molybdate, and tungstate competitively inhibited growth stimulation by molybdate.

  11. Outdoor PV Degradation Comparison

    SciTech Connect

    Jordan, D. C.; Smith, R. M.; Osterwald, C. R.; Gelak, E.; Kurtz, S. R.

    2011-02-01

    As photovoltaic (PV) penetration of the power grid increases, it becomes vital to know how decreased power output; may affect cost over time. In order to predict power delivery, the decline or degradation rates must be determined; accurately. At the Performance and Energy Rating Testbed (PERT) at the Outdoor Test Facility (OTF) at the; National Renewable Energy Laboratory (NREL) more than 40 modules from more than 10 different manufacturers; were compared for their long-term outdoor stability. Because it can accommodate a large variety of modules in a; limited footprint the PERT system is ideally suited to compare modules side-by-side under the same conditions.

  12. Study of the effect of γ-absorbed dose on degradation of polypropylene/starch-filled polymer containing photo-initiators by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Bagheri, Rouhollah.

    2009-09-01

    γ irradiated samples containing photo-initiators (PIs) with and without corn starch at 0-60 kGy were studied by UV spectrophotometer and FTIR. A linear decrease in the wavelength of absorbance maximum of each aromatic PI is observed by increase in the dose. The presence of starch in the sample caused a fluctuation of the absorptions. An increase in carbonyl formation due to the effect of a PI was detected. Ferric stearate and Irgacure 184 showed the highest and lowest effect respectively.

  13. Projectile penetration into ballistic gelatin.

    PubMed

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (<120m/s). The results of sphere penetration depth versus projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. © 2013 Published by Elsevier Ltd.

  14. Multifunctional Thin Film Biomatrice Biosensor in a Degradable Scaffold Containing Bone Morphogenetic Protein-2 (BMP-2) for Controlled Release in Skeletal Tissue Engineering

    NASA Astrophysics Data System (ADS)

    McDaniel, Harvey; Lomax, Linda

    2001-03-01

    Bone morphonogenetic proteins (BMP-2) have been under investigation for three decades. Deminerialized bone and extracts of deminerialized bone are o steoinductive with a temporal sequence of bone induction. Native and recombi nant BMP's have shown the ability, thru growth and differentiative factors t o induce de novo bone formation both invitro and invivo. Their principle fun ction is to induce transformation of undifferentiated mesenchymal cells into osteoblasts. Native and recombinant BMP's, when purified and used without carrier disp erse after implantation and exert no effect on bone induction. The delivery system provides the missing component to successsfully applying osteogenic p roteins for clinical need. Biological and physio-chemical properties are str ictly adhered tofor a successful delivery system. The BMP delivery system ca rrier for osteo inductive payload provided; 1)non tumorgenic genecity, 2) no n immunogenecity, 3) water insoluble, 4) biosorbability with predictable enz ymatic degradation, and 5) an optimized surface for compatibility, cell migr ation and attachment with a negative surface change that encouraged target c ell attachment. Being a controlled Release System, it binded the proteins wi th predictible BMP released kinetics. Porosity with interconnecting voids pr otected the BMP from noon specific proteolysis and promoted rapid vascular a nd mesenchymal invasion. Far wide ranging clinical applications of mechanica l and biofunctional requirements were met with the BMP delivery system. Cohe sion and malleability were reqiured forcontour augmentation, and reconstruct ion of the discontinuity defects, prevented dislocation and retained the sha pe and bone replaced the system. Biological systems have elastic activity associated with them. The activi ty was current associated with a time dependant biological/biochemical react ion (enzymic activity). Bioelectric phoenomena associated with charged molec ules in a biologic structure caused

  15. The Completely Sequenced Plasmid pEST4011 Contains a Novel IncP1 Backbone and a Catabolic Transposon Harboring tfd Genes for 2,4-Dichlorophenoxyacetic Acid Degradation

    PubMed Central

    Vedler, Eve; Vahter, Merle; Heinaru, Ain

    2004-01-01

    The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterium Achromobacter xylosoxidans subsp. denitrificans strain EST4002 contains plasmid pEST4011. This plasmid ensures its host a stable 2,4-D+ phenotype. We determined the complete 76,958-bp nucleotide sequence of pEST4011. This plasmid is a deletion and duplication derivative of pD2M4, the 95-kb highly unstable laboratory ancestor of pEST4011, and was self-generated during different laboratory manipulations performed to increase the stability of the 2,4-D+ phenotype of the original strain, strain D2M4(pD2M4). The 47,935-bp catabolic region of pEST4011 forms a transposon-like structure with identical copies of the hybrid insertion element IS1071::IS1471 at the two ends. The catabolic regions of pEST4011 and pJP4, the best-studied 2,4-D-degradative plasmid, both contain homologous, tfd-like genes for complete 2,4-D degradation, but they have little sequence similarity other than that. The backbone genes of pEST4011 are most similar to the corresponding genes of broad-host-range self-transmissible IncP1 plasmids. The backbones of the other three IncP1 catabolic plasmids that have been sequenced (the 2,4-D-degradative plasmid pJP4, the haloacetate-catabolic plasmid pUO1, and the atrazine-catabolic plasmid pADP-1) are nearly identical to the backbone of R751, the archetype plasmid of the IncP1 β subgroup. We show that despite the overall similarity in plasmid organization, the pEST4011 backbone is sufficiently different (51 to 86% amino acid sequence identity between individual backbone genes) from the backbones of members of the three IncP1 subgroups (the α, β, and γ subgroups) that it belongs to a new IncP1subgroup, the δ subgroup. This conclusion was also supported by a phylogenetic analysis of the trfA2, korA, and traG gene products of different IncP1 plasmids. PMID:15489427

  16. Evaluation of Microencapsulated Penetrant Inspection.

    DTIC Science & Technology

    1980-12-01

    AD-A9b 826 GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE GROUP F/6 IA/2ADG EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION.(U) DEC 80 J M...4156 ADA096826 EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION i :I J.M. Portaz Aircraft Engine Group General Electric Company Cincinnati, Ohio... Microencapsulated Penetrant 5 7riJF-Iehica17 = Inspection p un May@84 -1 ---- --- ---- 19AMFGK657j7 7. AiJTHOR(s) nVCWRACT OR GRANT m 𔃻 " JO J.M./Portaz

  17. Influence of some plant extracts on the transdermal absorption and penetration of marker penetrants.

    PubMed

    Muhammad, Faqir; Wiley, June; Riviere, Jim E

    2017-03-01

    ) penetrants and thus warrants the consideration as to their safety in cosmetics and topical pharmaceuticals containing natural extracts.

  18. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  19. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  20. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  1. An empirical equation for penetration depth of ogive-nose projectiles into concrete targets

    SciTech Connect

    Forrestal, M J; Altman, B S; Cargile, J D; Hanchak, S J

    1992-01-01

    We develop an empirical equation for penetration depth of ogive-nose projectiles penetrating concrete targets at normal impact. Our penetration equation contains a single, dimensionless empirical constant that depends only on the unconfined compressive strength of the target. We determine the empirical constant from penetration depth versus striking velocity data for targets with unconfined compressive strengths of nominally 14 MPa (2 ksi), 35 MPa (5 ksi), and 97 MPa (14 ksi). Predictions are in good agreement with six sets of penetration data for striking velocities between 250 and 800 m/s.

  2. Penetration Rates by Second-stage Juveniles of Meloidogyne spp. and Heterodera glycines into Soybean Roots

    PubMed Central

    Gourd, T. R.; Schmitt, D. P.; Barker, K. R.

    1993-01-01

    The rates of soybean root penetration by freshly hatched second-stage juveniles (J2) of Meloidogyne arenaria, M. hapla, M. incognita, M. javanica, and Heterodera glycines races 1 and 5 were examined over a period of 1 to 240 hours. Heterodera glycines entered roots more quickly than Meloidogyne spp. Penetration by most nematodes was accomplished within 48 hours. The increases in penetration after 48 hours were insufficient to warrant further assessments. Penetration of J2 into roots of soybean seedfings in a styrofoam container was as good or better than in a clay pot. Thus, rapid and accurate root-penetration assessments can be made at 48 hours after inoculation. PMID:19279739

  3. Penetrant-Indication-Measuring Compass

    NASA Technical Reports Server (NTRS)

    Schaefer, Lloyd

    1991-01-01

    Modified drafting compass well suited to measurement of length of crack or width of area stained by penetrant-dye-inspection method. Equipped with any of variety of standard curved or straight pointed tips. Modification consists in coating tips with dye that fluoresces light pink under same ultraviolet inspection light causing penetrant dye to fluoresce yellow green. Used in locations inaccessible to conventional fluorescent comparator. Eliminates errors of optical distortion in comparator, also eliminates errors of interpolation.

  4. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

  5. Impact of microbial growth inhibition and proteolytic activity on the stability of a new formulation containing a phytate-degrading enzyme obtained from mushroom.

    PubMed

    Spier, Michele R; Siepmann, Francieli B; Staack, Larissa; Souza, Priscila Z; Kumar, Vikas; Medeiros, Adriane B P; Soccol, Carlos R

    2016-10-02

    The development of stable enzymes is a key issue in both the food and feed industries. Consequently, the aim of the current study is to evaluate the impact of various additives (sodium chloride, sodium citrate, mannitol, methylparaben, polyethylene glycol 3350, ethylenediaminetetraacetic acid disodium salt, and a serine protease inhibitor) on the stability of a mushroom phytase produced by solid-state cultivation and recovery. Also observed was the effect of the additives on microbial growth inhibition by monitoring both the change in optical density over 30 days of storage and proteolytic activity. Initially, eight experimental formulations were prepared along with a control. After screening, a 3(2) factorial design was applied to define suitable concentrations of the selected additives. Among the eight formulations tested, the formulation containing NaCl, PEG 3350, and methylparaben retained all of the initial phytase activity after 50 days of storage, with no detected interference from protease activity. Sodium citrate, a metal chelation agent, presented the unusual effect of reducing protease activity in the formulations. Although all formulations presented better phytase stability when compared to the control, NaCl and PEG were both able to prolong the stability of the enzyme activity and also to inhibit microbial growth during storage, making them favorable for application as food and feed additives.

  6. Heat Loads Due to Small Penetrations in Multilayer Insulation Blankets

    NASA Technical Reports Server (NTRS)

    Johnson, W. L.; Heckle, K. W.; Fesmire, J. E.

    2017-01-01

    The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to each the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fouriers Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at 76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

  7. Penetration through the Skin Barrier.

    PubMed

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates. During recent decades, the latter has received increased attention as a route for intentionally delivering drugs to patients. This has stimulated research in methods for sampling, measuring and predicting percutaneous penetration. Previous chapters have described how different endogenous, genetic and exogenous factors may affect barrier characteristics. The present chapter introduces the theory for barrier penetration (Fick's law), and describes and discusses different methods for measuring the kinetics of percutaneous penetration of chemicals, including in vitro methods (static and flow-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous penetration. Finally, a short discussion of the advantages and challenges of each method is provided, which will hopefully allow the reader to improve decision making and treatment planning, as well as the evaluation of experimental studies of percutaneous penetration of chemicals. © 2016 S. Karger AG, Basel.

  8. Is Color Experience Cognitively Penetrable?

    PubMed

    Brogaard, Berit; Gatzia, Dimitria E

    2017-01-01

    Is color experience cognitively penetrable? Some philosophers have recently argued that it is. In this paper, we take issue with the claim that color experience is cognitively penetrable. We argue that the notion of cognitive penetration that has recently dominated the literature is flawed since it fails to distinguish between the modulation of perceptual content by non-perceptual principles and genuine cognitive penetration. We use this distinction to show that studies suggesting that color experience can be modulated by factors of the cognitive system do not establish that color experience is cognitively penetrable. Additionally, we argue that even if color experience turns out to be modulated by color-related beliefs and knowledge beyond non-perceptual principles, it does not follow that color experience is cognitively penetrable since the experiences of determinate hues involve post-perceptual processes. We conclude with a brief discussion of the implications that these ideas may have on debates in philosophy. Copyright © 2016 Cognitive Science Society, Inc.

  9. UP3005, a Botanical Composition Containing Two Standardized Extracts of Uncaria gambir and Morus alba, Improves Pain Sensitivity and Cartilage Degradations in Monosodium Iodoacetate-Induced Rat OA Disease Model

    PubMed Central

    Yimam, Mesfin; Lee, Young-Chul; Kim, Tae-Woo; Moore, Breanna; Jiao, Ping; Hong, Mei; Kim, Hyun-Jin; Nam, Jeong-Bum; Kim, Mi-Ran; Oh, Jin-Sun; Cleveland, Sabrina; Hyun, Eu-Jin; Chu, Min; Jia, Qi

    2015-01-01

    Osteoarthritis (OA) is a multifactorial disease primarily noted by cartilage degradation in association with inflammation that causes significant morbidity, joint pain, stiffness, and limited mobility. Present-day management of OA is inadequate due to the lack of principal therapies proven to be effective in hindering disease progression where symptomatic therapy focused approach masks the actual etiology leading to irreversible damage. Here, we describe the effect of UP3005, a composition containing a proprietary blend of two standardized extracts from the leaf of Uncaria gambir and the root bark of Morus alba, in maintaining joint structural integrity and alleviating OA associated symptoms in monosodium-iodoacetate- (MIA-) induced rat OA disease model. Pain sensitivity, micro-CT, histopathology, and glycosaminoglycans (GAGs) level analysis were conducted. Diclofenac at 10 mg/kg was used as a reference compound. UP3005 resulted in almost a complete inhibition in proteoglycans degradation, reductions of 16.6% (week 4), 40.5% (week 5), and 22.0% (week 6) in pain sensitivity, statistically significant improvements in articular cartilage matrix integrity, minimal visual subchondral bone damage, and statistically significant increase in bone mineral density when compared to the vehicle control with MIA. Therefore, UP3005 could potentially be considered as an alternative therapy from natural sources for the treatment of OA and/or its associated symptoms. PMID:25802546

  10. KCMF1 (potassium channel modulatory factor 1) Links RAD6 to UBR4 (ubiquitin N-recognin domain-containing E3 ligase 4) and Lysosome-Mediated Degradation*

    PubMed Central

    Hong, Jenny H.; Kaustov, Lilia; Coyaud, Etienne; Srikumar, Tharan; Wan, Janet; Arrowsmith, Cheryl; Raught, Brian

    2015-01-01

    RAD6 is a ubiquitin E2 protein with roles in a number of different biological processes. Here, using affinity purification coupled with mass spectrometry, we identify a number of new RAD6 binding partners, including the poorly characterized ubiquitin E3 ligases KCMF1 (potassium channel modulatory factor 1) and UBR4 (ubiquitin N-recognin domain-containing E3 ligase 4), a protein that can bind N-end rule substrates, and which was recently linked to lysosome-mediated degradation and autophagy. NMR, combined with in vivo and in vitro interaction mapping, demonstrate that the KCMF1 C terminus binds directly to RAD6, whereas N-terminal domains interact with UBR4 and other intracellular vesicle- and mitochondria-associated proteins. KCMF1 and RAD6 colocalize at late endosomes and lysosomes, and cells disrupted for KCMF1 or RAD6 function display defects in late endosome vesicle dynamics. Notably, we also find that two different RAD6A point mutants (R7W and R11Q) found in X-linked intellectual disability (XLID) patients specifically lose the interaction with KCMF1 and UBR4, but not with other previously identified RAD6 interactors. We propose that RAD6-KCMF1-UBR4 represents a unique new E2-E3 complex that targets unknown N-end rule substrates for lysosome-mediated degradation, and that disruption of this complex via RAD6A mutations could negatively affect neuronal function in XLID patients. PMID:25582440

  11. Macrophage-derived foam cells freshly isolated from rabbit atherosclerotic lesions degrade modified lipoproteins, promote oxidation of low-density lipoproteins, and contain oxidation-specific lipid-protein adducts.

    PubMed Central

    Rosenfeld, M E; Khoo, J C; Miller, E; Parthasarathy, S; Palinski, W; Witztum, J L

    1991-01-01

    Pure macrophage-derived foam cells (MFC) were isolated from the aortas of rabbits made atherosclerotic by balloon deendothelialization followed by diet-induced hypercholesterolemia. The MFC were isolated under sterile conditions using an enzymatic digestion procedure and discontinuous density gradient centrifugation. The purity of the MFC preparations was verified immunocytochemically with the macrophage specific monoclonal antibody RAM-11. MFC plated in medium containing 0.5% FCS for 24 h contained approximately 600 micrograms cholesterol per mg cell protein, 80% of which was esterified cholesterol. The MFC specifically degraded low density lipoprotein (LDL), acetyl-LDL, copper oxidized LDL, and beta-very low density lipoprotein (beta-VLDL) at rates comparable to mouse peritoneal macrophages (MPM) in 5-h assays. MFC within sections of the atherosclerotic lesions from the ballooned rabbits as well as the MFC isolated from the same lesions in the presence of antioxidants, exhibited positive immunoreactivity with polyclonal guinea pig antisera and mouse monoclonal antibodies directed against malondialdehyde-LDL, and 4-hydroxynonal-LDL. The MFC also exhibited the capacity to induce the oxidation of LDL at rates comparable to those exhibited by MPM and rabbit aortic endothelial cells. These data provide direct evidence that arterial wall macrophages express modified LDL receptors in vivo, contain epitopes found in oxidized-LDL and are capable of oxidizing LDL even when maximally loaded with cholesterol. Images PMID:1985115

  12. Root penetration through sealing layers at mine deposit sites.

    PubMed

    Stoltz, Eva; Greger, Maria

    2006-12-01

    To prevent acid mine drainage arising from oxygen and water penetration of sulphide-rich mine tailings, the tailings are covered with layers of dry sealing material. Plant roots have a great ability to penetrate dense materials, and if the roots are able to penetrate the sealing layer of a tailings deposit, its oxygen-shielding properties could be reduced. The objective of this study was to evaluate whether plant roots are able to penetrate sealing layers covering mine tailings deposits. Root penetration into layers of various sealing materials, such as clayey moraine (clay, 8-10%; silt, 22-37%; sand, 37-55%; gravel, 15-18%), moraine (unspecified), 6-mm bentonite (kaolin clay) fabric, lime and clay, Cefyll (mixture of pulverized coal fly ash, cement and water) and a mixture containing biosludge (30-35%) and bioashes (65-70%), was investigated. In the field, roots were studied by digging trenches alongside vegetation growing in 3- and 10-year-old mine sites. In the greenhouse root growth of Betula pendula, Pinus sylvestris, Poa pratensis and Salix viminalis were studied in compartments where the plants had been growing for 22 months. The results from the field experiment indicated that roots are able to penetrate both deep down in the cover layer (1.7 m) and also into the sealing layers of various materials, and even to penetrate hard Cefyll. The addition of nutrients in the top cover reduced deep root growth and thereby also penetration through the sealing layer. Low hydraulic conductivity of the sealing layer or a thick cover layer had less effect on root penetration. In the greenhouse experiment roots did not penetrate the thin bentonite fabric, due to low pH (2.1-2.7) that was created from the underlying weathered mine tailings. The clayey moraine was penetrated by all species used in the greenhouse experiment; Pinus sylvestris had the greatest ability to penetrate. To prevent root penetration of the other sealing layer, a suitable condition for the plants

  13. Filter Enhances Fluorescent-Penetrant-Inspecting Borescope

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Slip-on eyepiece for commercial ultraviolet-light borescope reduces both amount of short-wave ultraviolet light that reaches viewer's eye and apparent intensity of unwanted reflections of white light from surfaces undergoing inspection. Fits on stock eyepiece of borescope, which illuminates surface inspected with intense ultraviolet light. Surface, which is treated with fluorescent dye, emits bright-green visible light wherever dye penetrates - in cracks and voids. Eyepiece contains deep-yellow Wratten 15 (G) filter, which attenuates unwanted light strongly but passes yellow-green fluorescence so defects seen clearly.

  14. A β-Alanine Catabolism Pathway Containing a Highly Promiscuous ω-Transaminase in the 12-Aminododecanate-Degrading Pseudomonas sp. Strain AAC

    PubMed Central

    Wilding, Matthew; Peat, Thomas S.; Newman, Janet

    2016-01-01

    ABSTRACT We previously isolated the transaminase KES23458 from Pseudomonas sp. strain AAC as a promising biocatalyst for the production of 12-aminododecanoic acid, a constituent building block of nylon-12. Here, we report the subsequent characterization of this transaminase. It exhibits activity with a broad substrate range which includes α-, β-, and ω-amino acids, as well as α,ω-diamines and a number of other industrially relevant compounds. It is therefore a prospective candidate for the biosynthesis of a range of polyamide monomers. The crystal structure of KES23458 revealed that the protein forms a dimer containing a large active site pocket and unusual phosphorylated histidine residues. To infer the physiological role of the transaminase, we expressed, purified, and characterized a dehydrogenase from the same operon, KES23460. Unlike the transaminase, the dehydrogenase was shown to be quite selective, catalyzing the oxidation of malonic acid semialdehyde, formed from β-alanine transamination via KES23458. In keeping with previous reports, the dehydrogenase was shown to catalyze both a coenzyme A (CoA)-dependent reaction to form acetyl-CoA and a significantly slower CoA-independent reaction to form acetate. These findings support the original functional assignment of KES23458 as a β-alanine transaminase. However, a seemingly well-adapted active site and promiscuity toward unnatural compounds, such as 12-aminododecanoic acid, suggest that this enzyme could perform multiple functions for Pseudomonas sp. strain AAC. IMPORTANCE We describe the characterization of an industrially relevant transaminase able to metabolize 12-aminododecanoic acid, a constituent building block of the widely used polymer nylon-12, and we report the biochemical and structural characterization of the transaminase protein. A physiological role for this highly promiscuous enzyme is proposed based on the characterization of a related gene from the host organism. Molecular dynamics

  15. Constitutive models in WONDY for penetration studies into rock targets

    SciTech Connect

    Norwood, F.R.

    1981-09-01

    Computer simulation appears to be the easiest way of providing a fairly complete description of the physical problem of earth penetration by projectiles. This simulation is limited by the lack of information on the behavior of geologic targets under dynamic loading and also by the description of the constitutive model for the geologic material. Several constitutive models are presented for possible applications to the rock and rock-like materials. Using material property data for Antelope tuff, the required set of constants for each model was selected and used in predicting, for a penetration event, stress distributions on the penetrator surface and also penetration histories. For each of these three models, the average decelerations lie close to the values computed for coefficients of friction of zero and 0.1. Assuming zero friction, curves of deceleration as a function of penetration depth were calculated for the various models. These curves were higher than the experimental curve for the first meter of penetration. This seems to indicate that the models considered here do not contain all the physical details needed for a more accurate prediction. In studies of friction at high speed, the coefficient of friction has been found to increase qualitatively as an exponential function as the velocity decreases. This might possibly explain the lock-in phenomenon occurring at the end of a penetration event. As part of the present study, parameter variation studies were conducted to determine which material properties would be most significant in earth penetration by projectiles. Material compressibility, cohesive strength and internal friction angle were examined in detail. The internal friction angle was found to be the most important and cohesive strength the least important parameter in contributing to the resistive forces experienced by a projectile during penetration.

  16. Susceptibility of polysiloxane and colloidal silica to degradation by soil microorganisms

    SciTech Connect

    Lundy, D.Z.; Hunter-Cevera, J.C.; Moridis, G.J.

    1997-11-01

    This report is a description of the laboratory study undertaken to determine the biodegradability of Colloidal Silica (CS) and PolySiloXane (PSX), a new generation of barrier liquids employed by the Viscous Liquid Barrier (VLB) technology in the containment of subsurface contaminants. Susceptibility of either material to microbial degradation would suggest that the effectiveness of a barrier in the subsurface may deteriorate over time. Degradation may result from several different biological events. Organisms may consume the material as a carbon and/or energy source, organisms may chemically change the material as a detoxification mechanism, or organisms may erode the material by their physical penetration of the material during growth. To determine if degradation occurs, physical interactions between soil microbes and the barrier materials were analyzed, and the metabolic activity of individual organisms in the presence of CS and PSX was measured.

  17. Penetration and fusion of phospholipid vesicles by lysozyme

    SciTech Connect

    Kim, J.; Kim, H.

    1989-10-01

    The lysozyme-induced fusion of phosphatidylserine/phosphatidylethanolamine vesicles as studied at a wide range of pH is found to correlate well with the binding of this protein to the vesicles. An identical 6000 molecular weight segment of lysozyme at the N-terminal region is found to be protected from tryptic digestion when initially incubated with vesicles at several pH values. Only this segment is labeled by dansyl chloride, which is partitioned into the bilayer. These results suggest the penetration of one segment of lysozyme into the bilayer. Photoactivated labeling of the membrane-penetrating segment of lysozyme with 3-(trifluoromethyl)-3-(({sup 125}I)iodophenyl)diazirine (({sup 125}I)TID) and subsequent identification of the labeled residues by Edman degradation and gamma-ray counting indicate that four amino acids from the N-terminal are located outside the hydrophobic core of the bilayer. Although treatment of the membrane-embedded segment with aminopeptidase failed to cleave any amino acids from the N-terminal, it appears that a loop of lysozyme segment near the N-terminal penetrates into the bilayer at acidic pH. A helical wheel diagram shows that the labeling is done mainly on one surface of the alpha-helix. The penetration kinetics as studied by time-dependent ({sup 125}I)TID labeling coincide with the fusion kinetics, strongly suggesting that the penetration of the lysozyme segment into the vesicles is the cause of the fusion.

  18. Photovoltaic Degradation Rates -- An Analytical Review

    SciTech Connect

    Jordan, D. C.; Kurtz, S. R.

    2012-06-01

    As photovoltaic penetration of the power grid increases, accurate predictions of return on investment require accurate prediction of decreased power output over time. Degradation rates must be known in order to predict power delivery. This article reviews degradation rates of flat-plate terrestrial modules and systems reported in published literature from field testing throughout the last 40 years. Nearly 2000 degradation rates, measured on individual modules or entire systems, have been assembled from the literature, showing a median value of 0.5%/year. The review consists of three parts: a brief historical outline, an analytical summary of degradation rates, and a detailed bibliography partitioned by technology.

  19. Double-Plate Penetration Equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    2000-01-01

    This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

  20. Influence of the Vehicle on the Penetration of Particles into Hair Follicles

    PubMed Central

    Patzelt, Alexa; Richter, Heike; Dähne, Lars; Walden, Peter; Wiesmüller, Karl-Heinz; Wank, Ute; Sterry, Wolfram; Lademann, Jürgen

    2011-01-01

    Recently, it has been demonstrated that particulate substances penetrate preferentially into the hair follicles and that the penetration depth depends on the particle size. In the present study, the influence of the vehicle of the particulate substances on the penetration depth was investigated. Four different formulations (ethanolic suspension, aqueous suspension, ethanolic gel and aqueous gel) containing peptide-loaded particles of 1 μm in diameter were prepared and applied on porcine ear skin. After penetration, punch biopsies were taken and the penetration depths of the particles were investigated by laser scanning microscopy. The deepest penetration was achieved with the gel formulations demonstrating an influence of the vehicle on the penetration depth of particulate substances. PMID:24310497

  1. [Penetrating transorbital intracranial foreign body].

    PubMed

    Civelek, Erdinç; Bilgiç, Salih; Kabataş, Serdar; Hepgül, Kemal Tanju

    2006-07-01

    We report a seven year-old boy who suffered left orbital penetration of an industrial sewing machine needle. The needle passing through the left orbit and sphenoid bone at the posterior was extending into the layers of the dura of the left temporal lobe. In this patient, we preferred surgical approach and there was no complication after surgery. Penetrating intraorbital foreign materials with intracranial extension may lead to complications such as intracerebral hematoma, brain abscess, CSF fistula, proptosis of the eye, diplopia, orbital cellulitis and periorbital abscess. They have to be removed by surgical approach to prevent potential complications.

  2. Fluconazole Penetration into the Pancreas

    PubMed Central

    Shrikhande, Shailesh; Friess, Helmut; Issenegger, Claudia; Martignoni, Marcus E.; Yong, Huang; Gloor, Beat; Yeates, Rodney; Kleeff, Jörg; Büchler, Markus W.

    2000-01-01

    Because of antibiotic prophylaxis for necrotizing pancreatitis, the frequency of fungal superinfection in patients with pancreatic necrosis is increasing. In this study we analyzed the penetration of fluconazole into the human pancreas and in experimental acute pancreatitis. In human pancreatic tissues, the mean fluconazole concentration was 8.19 ± 3.38 μg/g (96% of the corresponding concentration in serum). In experimental edematous and necrotizing pancreatitis, 88 and 91% of the serum fluconazole concentration was found in the pancreas. These data show that fluconazole penetration into the pancreas is sufficient to prevent and/or treat fungal contamination in patients with pancreatic necrosis. PMID:10952621

  3. Mars surface penetrator: System description

    NASA Technical Reports Server (NTRS)

    Manning, L. A. (Editor)

    1977-01-01

    A point design of a penetrator system for a Mars mission is described. A strawman payload which is to conduct measurements of geophysical and meteorological parameters is included in the design. The subsystems used in the point design are delineated in terms of power, mass, volume, data, and functional modes. The prospects for survival of the rigors of emplacement are described. Data handling and communications plans are presented to allow consideration of the requirements placed by the penetrator on the orbiter and ground operations. The point design is technically feasible and the payload selection scientifically desirable.

  4. A bioassay to estimate root penetration by nematodes.

    PubMed

    Kaplan, D T; Davis, E L

    1991-10-01

    An in vitro bioassay with a 96-well microtiter plate was used to study the effect of lectins on burrowing nematode penetration of citrus roots. In each well, one 4-mm root segment, excised from the zone of elongation of rough lemon roots, was buried in 0.88 g dry sand. Addition of a Radopholus citrophilus suspension containing ca. 300 nematodes in 50 mu1 test solution completely moistened the sand in each well. The technique assured uniform treatment concentration throughout the medium. Within 16-24 hours, burrowing nematodes penetrated citrus root pieces, primarily through the cut ends. The lectins (100 mug/ml) Concanavalin A (Con A), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and Lotus tetragonolobus agglutinin (LOT) stimulated an increase in penetration of citrus root segments by Radopholus citrophilus. Concentrations as low as 12.5 mug/ml Con A, LOT, and WGA stimulated burrowing nematode penetration of citrus roots. Heat denaturation of the lectins reversed their effect on penetration; however, incubation of nematodes in lectin (25 mug/ml) with 25 mM competitive sugars did not. The reason for enhanced penetration associated with lectins is unclear.

  5. Role of complexes formation between drugs and penetration enhancers in transdermal delivery.

    PubMed

    Drakulić, Branko J; Juranić, Ivan O; Erić, Slavica; Zloh, Mire

    2008-11-03

    The use of chemical penetration enhancers (CPE) is growing due to their ability to improve drug delivery through the skin. A possible mechanism of penetration enhancement could involve the complex formation between drug and components in the pharmaceutical formulation, thus altering the physicochemical properties of the active substance. Here, modelling studies indicate that hydrocarbon and oxygen-containing terpenes (penetration enhancers) could form complexes with drugs. Satisfactory correlations have been obtained between the predicted molecular properties of enhancers and their enhancement effects.

  6. Fracture Fluid Additive and Formation Degradations

    EPA Pesticide Factsheets

    This presentation is on reactions that describe the degradation of fracturing fluids & formations during the hydraulic fracturing process & the clean‐up period. It contains a description of primary chemical reaction controls, & common degradation reactions

  7. FAA Fluorescent Penetrant Laboratory Inspections

    SciTech Connect

    WINDES,CONNOR L.; MOORE,DAVID G.

    2000-08-02

    The Federal Aviation Administration Airworthiness Assurance NDI Validation Center currently assesses the capability of various non-destructive inspection (NDI) methods used for analyzing aircraft components. The focus of one such exercise is to evaluate the sensitivity of fluorescent liquid penetrant inspection. A baseline procedure using the water-washable fluorescent penetrant method defines a foundation for comparing the brightness of low cycle fatigue cracks in titanium test panels. The analysis of deviations in the baseline procedure will determine an acceptable range of operation for the steps in the inspection process. The data also gives insight into the depth of each crack and which step(s) of the inspection process most affect penetrant sensitivities. A set of six low cycle fatigue cracks produced in 6.35-mm thick Ti-6Al-4V specimens was used to conduct the experiments to produce sensitivity data. The results will document the consistency of the crack readings and compare previous experiments to find the best parameters for water-washable penetrant.

  8. Penetrating trauma to the extremity.

    PubMed

    Manthey, David E; Nicks, Bret A

    2008-02-01

    Penetrating trauma to the extremities is a complex disease that foremost requires the evaluation for vascular injury. This monograph will address an algorithm to assess for associated vascular injury that includes current evaluation techniques. Approaches to wound management and use of antibiotics in the ED are also addressed.

  9. Localizing Ground-Penetrating Radar

    DTIC Science & Technology

    2014-11-01

    determine the vehicles location when adverse conditions, such as heavy rain or fog , snow-covered roads, or lost GPS signals, hamper the...penetrate rain, fog , dust, and snow. LGPR Methodology For subsurface sensing, GPR is one of the most versatile and prolific sensing modal- ities today

  10. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  11. A penetrating orbitocranial stab wound.

    PubMed Central

    MacEwen, C J; Fullarton, G

    1986-01-01

    An unusual case of intracranial penetration of a bread knife through the orbit is described. Despite the proximity of the blade to the internal carotids, the optic nerves and chiasm, and the pituitary the patient survived with only a minimal field defect affecting the eye opposite to the entry site; otherwise no neurological or endocrine deficit was evident. Images PMID:3947613

  12. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  13. CONTAINER MATERIALS, FABRICATION AND ROBUSTNESS

    SciTech Connect

    Dunn, K.; Louthan, M.; Rawls, G.; Sindelar, R.; Zapp, P.; Mcclard, J.

    2009-11-10

    The multi-barrier 3013 container used to package plutonium-bearing materials is robust and thereby highly resistant to identified degradation modes that might cause failure. The only viable degradation mechanisms identified by a panel of technical experts were pressurization within and corrosion of the containers. Evaluations of the container materials and the fabrication processes and resulting residual stresses suggest that the multi-layered containers will mitigate the potential for degradation of the outer container and prevent the release of the container contents to the environment. Additionally, the ongoing surveillance programs and laboratory studies should detect any incipient degradation of containers in the 3013 storage inventory before an outer container is compromised.

  14. Varying termiticide application rate and volume affect initial soil penetration

    Treesearch

    Christopher Peterson

    2010-01-01

    The initial soil penetration of Premise 75 and Termidor SC, containing imidacloprid and fipronil, respectively, were tested in laboratory columns of five different soils. Three combinations of application concentration and volume were used: double the recommended active ingredient concentration at one half the recommended volume (DR), the full concentration and volume...

  15. Nonhost Root Penetration by Soybean Cyst Nematode

    PubMed Central

    Riggs, R. D.

    1987-01-01

    A total of 66 plants in 50 species were inoculated with eggs and juveniles of soybean cyst nematode, Heterodera glycines. Roots were stained and observed for penetration and development of the nematode. Twenty-six plants were not penetrated; twenty-three were penetrated, but there was no development of the nematode; eight were penetrated with some nematode development; two were penetrated and had considerable nematode development, but few nematodes, if any, matured; and seven were penetrated with many nematodes maturing. The penetration of nonhosts may imply some susceptibility and that populations eventually would build up on the penetrated plants. Plants not penetrated may be useful as rotation plants because no reproduction would occur. PMID:19290137

  16. Penetration of nanoparticles into human skin.

    PubMed

    Liang, Xiao Wen; Xu, Zhi Ping; Grice, Jeffrey; Zvyagin, Andrei V; Roberts, Michael S; Liu, Xin

    2013-01-01

    Exposure of human skin to nanoparticles (NPs) is increasing with the development of nanotechnology and new applications of NPs in medicine. Safety concerns have sparked debate on the capacity of NPs to penetrate through skin and enter into the body. This article attempts to summarize the recent evidence on whether NPs penetrate human skin and the factors that may affect the penetration. Skin structure and penetration mechanisms are reviewed to provide background information. Size, shape, formulation, surface properties and application methods and their effects on skin penetration are specifically discussed. Finally, the relationship between skin penetration and nanotoxicity is reviewed to further emphasise the importance of the research in this area.

  17. Akon - A Penetrator for Europa

    NASA Astrophysics Data System (ADS)

    Jones, Geraint

    2016-04-01

    Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

  18. Polyanhydride degradation and erosion.

    PubMed

    Göpferich, A; Tessmar, J

    2002-10-16

    It was the intention of this paper to give a survey on the degradation and erosion of polyanhydrides. Due to the multitude of polymers that have been synthesized in this class of material in recent years, it was not possible to discuss all polyanhydrides that have gained in significance based on their application. It was rather the intention to provide a broad picture on polyanhydride degradation and erosion based on the knowledge that we have from those polymers that have been intensively investigated. To reach this goal this review contains several sections. First, the foundation for an understanding of the nomenclature are laid by defining degradation and erosion which was deemed necessary because many different definitions exist in the current literature. Next, the properties of major classes of anhydrides are reviewed and the impact of geometry on degradation and erosion is discussed. A complicated issue is the control of drug release from degradable polymers. Therefore, the aspect of erosion-controlled release and drug stability inside polyanhydrides are discussed. Towards the end of the paper models are briefly reviewed that describe the erosion of polyanhydrides. Empirical models as well as Monte-Carlo-based approaches are described. Finally it is outlined how theoretical models can help to answer the question why polyanhydrides are surface eroding. A look at the microstructure and the results from these models lead to the conclusion that polyanhydrides are surface eroding due to their fast degradation. However they switch to bulk erosion once the device dimensions drop below a critical limit.

  19. Multi-well sample plate cover penetration system

    DOEpatents

    Beer, Neil Reginald [Pleasanton, CA

    2011-12-27

    An apparatus for penetrating a cover over a multi-well sample plate containing at least one individual sample well includes a cutting head, a cutter extending from the cutting head, and a robot. The cutting head is connected to the robot wherein the robot moves the cutting head and cutter so that the cutter penetrates the cover over the multi-well sample plate providing access to the individual sample well. When the cutting head is moved downward the foil is pierced by the cutter that splits, opens, and folds the foil inward toward the well. The well is then open for sample aspiration but has been protected from cross contamination.

  20. IPMN penetration of the stomach.

    PubMed

    Nakano, Masakazu; Tominaga, Keiichi; Watanabe, Hidetaka; Kanke, Kazunari; Tamano, Masaya; Hiraishi, Hideyuki

    2010-01-01

    An 83-year old Japanese man was transferred to our hospital due to a 1-week history of melena and signs of disordered awareness. Esophagogastroduodenoscopy showed a villous tumor associated with massive white mucous discharge in the posterior wall of the gastric corpus, where pathologically identified mucin-producing epithelium with nuclear atypia had developed into a papillary form. An abdominal enhanced computed tomography scan demonstrated communication between the dilated main pancreatic duct and the gastric lumen. Based on these findings, we reached a diagnosis of gastric penetration by an intraductal papillary mucinous neoplasm (IPMN) of the main pancreatic duct. IPMN is partly characterized by expansive mucinous growth that may result in penetration into adjacent organs.

  1. Method and apparatus for transport, introduction, atomization and excitation of emission spectrum for quantitative analysis of high temperature gas sample streams containing vapor and particulates without degradation of sample stream temperature

    DOEpatents

    Eckels, David E.; Hass, William J.

    1989-05-30

    A sample transport, sample introduction, and flame excitation system for spectrometric analysis of high temperature gas streams which eliminates degradation of the sample stream by condensation losses.

  2. Computational Model for Armor Penetration

    DTIC Science & Technology

    1987-10-01

    the penetration calculation with a slide line in the target, the impact velocity was artificially raised to avoid impact of the projectile sides onto...Lagrangian equations governing motion of a continuous medium. The solution technique is called the method of artificial viscosity because of the...fronts, although no discontinuities occur in the computed flow field. With this artificial viscosity method, the equations of continuous flow can be

  3. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  4. Fragment Penetration Tests of Armor

    DTIC Science & Technology

    1983-03-15

    Identify by block numbhr) Provides techniques for evaluating armor resistance to attack by HE projectile fragments. Includes static detonations of shell...DISTRIBUTION D. REFERENCES * . . . ........ . ........... D-1 1. SCOPE. This TOP describes the available techniques for testing armor for resistance to attack by...Projectiles Against Armor Plates ("Yankee Stadium" Test-). 4.1.1 hCjective. The objective is to determine the resistance to penetration of various armor

  5. Penetration Enzymes of Schistosome Cercariae.

    DTIC Science & Technology

    1982-10-12

    82 10 29 025 SUMMARY In view of the facts that schistosomiasis Is one of man’s most important infectious tropical diseases and that our present...schistosomules; *: (4) differences in intraspecific geographical strains of Schistosoma mansoni ; and (5) snail-parasite relationships. (1) Cercarial Enzymes...of schistosomiasis , a critical stage in the infective process needing elucidation is the transformation In skin of the penetrating cercarlae to the

  6. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  7. Liquid penetration of barrier materials

    NASA Astrophysics Data System (ADS)

    Miller, Angela Maria

    1998-12-01

    Liquid penetration of porous materials is important for applications such as protective clothing, resin impregnation of fibers for composites, and filtration. A test apparatus for determining pressure at liquid breakthrough as a function of flow rate has been designed and constructed. Using this method, it was determined that liquid penetration of a material produces an interesting pressure curve where liquid breakthrough is followed by a peak in pressure and then a drop corresponding to equilibrium flow. This test method allows for comparison of materials in terms of barrier performance and also gives insight into the liquid saturation process. Three materials were tested with water as challenge liquids of varying viscosity and wettability. It was determined that pressure at liquid breakthrough was not dependent on the flow rate nor the viscosity of the challenge liquid but was dependent on the wettability of the challenge liquid. Also of interest was that more passages were opened through the material as flow rate was increased. A numerical model of liquid penetration of a barrier material was created based on invasion percolation. The model has been shown to be consistent with experimental results.

  8. Penetration and Splitting of Optic Nerve by Tuberculum Sellae Meningioma

    PubMed Central

    Park, Seong-Cheol

    2016-01-01

    Preservation of the optic nerves is an important issue in the resection of tuberculum sellae meningiomas. We report the case of a patient whose optic nerve was penetrated by a tuberculum sellae meningioma. During surgery, a bulging tumor was found to penetrate the right optic nerve. The tumor was gross totally removed, including tumors bulging through the optic nerve. Two trunks of the split optic nerve were preserved. The penetrated shape of the optic nerve may lead to misjudgment and its damage. Divided trunks of optic nerves are difficult to recognize and may be confused for the tumor capsule, because they may be thinned and seem to contain tumors. In addition, a single trunk may be confused for the whole nerve; thus, the other trunk may be easily damaged if not dissected cautiously. Treatment strategy according to the remnant visual acuity was suggested. PMID:27651874

  9. Behavior of Segmented Rods during Penetration

    DTIC Science & Technology

    1990-07-01

    full-scale penetrators which had been swaged 24%. The density of this tungsten alloy was 17.2 Mg/m 3. Gold-alloy penetrators were composed of 92Au-4.9Ag...of behavior. Segmented rods of tungsten alloy always penetrated less than the equivalent unitary rod. Successive rod segments were found to...gold-alloy penetrators because unitary rods of this material surpassed the perform- ance of unitary tungsten -alloy rods, while leaving almost no

  10. Network Penetration Testing and Research

    NASA Technical Reports Server (NTRS)

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised

  11. Standard Penetration Test and Relative Density

    DTIC Science & Technology

    1971-02-01

    penetration resistan ( e of soil, an empirical relation was established between the number of blows applied in the standard pene- tration test to sand below...more to a change in the mean grain diameter than did the pene- trometer in the standard penetration test. CONC LUSIONS In the standard penetration

  12. Effect of compressibility on the hypervelocity penetration

    NASA Astrophysics Data System (ADS)

    Song, W. J.; Chen, X. W.; Chen, P.

    2017-06-01

    We further consider the effect of rod strength by employing the compressible penetration model to study the effect of compressibility on hypervelocity penetration. Meanwhile, we define different instances of penetration efficiency in various modified models and compare these penetration efficiencies to identify the effects of different factors in the compressible model. To systematically discuss the effect of compressibility in different metallic rod-target combinations, we construct three cases, i.e., the penetrations by the more compressible rod into the less compressible target, rod into the analogously compressible target, and the less compressible rod into the more compressible target. The effects of volumetric strain, internal energy, and strength on the penetration efficiency are analyzed simultaneously. It indicates that the compressibility of the rod and target increases the pressure at the rod/target interface. The more compressible rod/target has larger volumetric strain and higher internal energy. Both the larger volumetric strain and higher strength enhance the penetration or anti-penetration ability. On the other hand, the higher internal energy weakens the penetration or anti-penetration ability. The two trends conflict, but the volumetric strain dominates in the variation of the penetration efficiency, which would not approach the hydrodynamic limit if the rod and target are not analogously compressible. However, if the compressibility of the rod and target is analogous, it has little effect on the penetration efficiency.

  13. Toody-Wondy calculations of penetration events

    NASA Astrophysics Data System (ADS)

    Hicks, D. L.; Norwood, F. R.; Trucano, T. G.

    1982-04-01

    One and two-dimensional Lagrangian wavecode calculations simulating penetration of a conical-nosed steel penetrator into Antelope Lake Tuff are summarized. These calculations are used to investigate the validity of the cylindrical cavity expansion theory, which has been used to simplify the analysis of earth-penetration events.

  14. TOODY-WONDY calculations of penetration events

    SciTech Connect

    Hicks, D.L.; Norwood, F.R.; Trucano, T.G.

    1981-01-01

    One- and two-dimensional Lagrangian wavecode calculations simulating penetration of a conical-nosed steel penetrator into Antelope Lake Tuff are summarized. These calculations are used to investigate the validity of the cylindrical cavity expansion theory, which has been used to simplify the analysis of earth-penetration events.

  15. Evaluation of nicotinamide microemulsion on the skin penetration enhancement.

    PubMed

    Boonme, Prapaporn; Boonthongchuay, Chalida; Wongpoowarak, Wibul; Amnuaikit, Thanaporn

    2016-01-01

    This study purposed to evaluate a microemulsion containing nicotinamide for its characteristics, stability, and skin penetration and retention comparing with a solution of nicotinamide in 2:1 mixture of water and isopropyl alcohol (IPA). The microemulsion system was composed of 1:1 mixture of Span80 and Tween80 as a surfactant mixture, isopropyl palmitate (IPP) as an oil phase, and 2:1 mixture of water and IPA as an aqueous phase. Nicotinamide microemulsion was prepared by dissolving the active in the aqueous phase before simply mixing with the other components. It was determined for its characteristics and stability under various conditions. The skin penetration and retention studies of nicotinamide microemulsion and solution were performed by modified Franz diffusion cells, using newborn pig skin as the membrane. The results showed that nicotinamide microemulsion could be obtained as clear yellowish liquid, was water-in-oil (w/o) type, possessed Newtonian flow, and exhibited physicochemical stability when kept at 4 °C and room temperature (≈30 ± 2 °C) during 3 months. From the skin penetration data, the microemulsion could enhance the skin penetration of nicotinamide comparing with the solution. Additionally, nicotinamide microemulsion could provide much higher amount of skin retention than that of skin penetration, resulting in suitability for a cosmeceutical product.

  16. Direct measurement of chlorine penetration into biofilms during disinfection.

    PubMed Central

    De Beer, D; Srinivasan, R; Stewart, P S

    1994-01-01

    Transient chlorine concentration profiles were measured in biofilms during disinfection by use of a microelectrode developed for this investigation. The electrode had a tip diameter of ca. 10 microm and was sensitive to chlorine in the micromolar range. The biofilms contained Pseudomonas aeruginosa and Klebsiella pneumoniae. Chlorine concentrations measured in biofilms were typically only 20% or less of the concentration in the bulk liquid. Complete equilibration with the bulk liquid did not occur during the incubation time of 1 to 2 h. The penetration depth of chlorine into the biofilm and rate of penetration varied depending on the measurement location, reflecting heterogeneity in the distribution of biomass and in local hydrodynamics. The shape of the chlorine profiles, the long equilibration times, and the dependence on the bulk chlorine concentration showed that the penetration was a function of simultaneous reaction and diffusion of chlorine in the biofilm matrix. Frozen cross sections of biofilms, stained with a redox dye and a DNA stain, showed that the area of chlorine penetration overlapped with nonrespiring zones near the biofilm-bulk fluid interface. These data indicate that the limited penetration of chlorine into the biofilm matrix is likely to be an important factor influencing the reduced efficacy of this biocide against biofilms as compared with its action against planktonic cells. PMID:7811074

  17. Cutaneous Penetration Enhancing Effect of Menthol: Calcium Involvement.

    PubMed

    Joshi, Amit; Joshi, Abhay; Patel, Hiren; Ponnoth, Dovenia; Stagni, Grazia

    2017-04-08

    Menthol is a naturally occurring terpene used as a penetration enhancer in topical and transdermal formulations. Literature shows a growing interest on menthol's interactions with the Transient-Receptor-Potential (TRPM-8) calcium channel. A decrease in extracellular Ca(+2) due to the activation of TRPM-8 channels produces inhibition of E-cadherin expression that is responsible for cell-cell adhesion. Since calcium is present in the entire epidermis, the purpose of this study is to evaluate whether the aforementioned properties of menthol are also related to its penetration-enhancing-effects. We formulated sixteen gels: (i) drug-alone (diphenhydramine or lidocaine), (ii) drug with menthol, (iii) drug, menthol, and calcium channel blocker (verapamil or diltiazem), and (iv) drug and calcium channel blocker (CCB). In-vitro studies showed no effect of the CCB on the release of the drugs either with or without menthol. In-vivo experiments were performed for each drug/menthol/CCB combination gel by applying four formulations on a shaved rabbit's dorsum on the same day. Dermis concentration profiles were assessed with microdialysis. The gels containing menthol showed higher penetration of drugs than those without whereas the addition of the CCB consistently inhibited the penetration-enhancing-effects of menthol. In summary, these findings strongly support the involvement of calcium in the penetration-enhancing-effect of menthol.

  18. Effects of neutral pH and low-glucose degradation product-containing peritoneal dialysis fluid on systemic markers of inflammation and endothelial dysfunction: a randomized controlled 1-year follow-up study.

    PubMed

    Park, Sun-Hee; Do, Jun-Young; Kim, Yeong Hoon; Lee, Ho Yung; Kim, Beom Seok; Shin, Sug-Kyun; Kim, Hyun Chul; Chang, Yoon-Kyung; Yang, Jong-Oh; Chung, Hyun-Chul; Kim, Chan-Duck; Lee, Won Kee; Kim, Jong-Yeon; Kim, Yong-Lim

    2012-03-01

    The local peritoneal effects of low-glucose degradation product (GDP)-containing peritoneal dialysis fluid (PDF) have been extensively described. However, the systemic effects of prolonged prescription of these solutions are unknown. This study aimed to evaluate the effects of neutral pH and low-GDP PDF on systemic inflammation and endothelial dysfunction markers in peritoneal dialysis (PD) patients. This is a multicenter, open labeled, randomized controlled trial including one hundred fifty-two patients initiating continuous ambulatory peritoneal dialysis for end-stage renal disease from seven centers in Korea. Participants were randomly allocated to conventional PDF (Stay safe®; Fresenius Medical Care, Bad Homburg, Germany) or low-GDP PDF (Balance®; Fresenius Medical Care) and were followed for 1 year. Primary outcome variable was the inflammation and endothelial dysfunction index (IEDI), a composite score derived from serum levels of soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cellular adhesion molecule (sVCAM)-1 and high-sensitivity C-reactive protein (hs-CRP). sICAM-1, sVCAM-1, residual renal function (RRF), peritoneal membrane transport characteristics, ultrafiltration volume and nutritional parameters were measured as secondary outcome variables. Of 152 patients randomized, 146 (low-GDP: conventional PDF, 79:67) patients entered the trial (46% male, 53% with diabetes mellitus). At 12-month follow-up, the low-GDP group had significantly lower levels of IEDI, sICAM-1 and sVCAM-1 compared to the conventional group; hs-CRP was not different between groups. Peritoneal transport characteristics, RRF, nutritional parameters, incidence of peritonitis and death-censored technique survival were not different between groups. Neutral pH and low-GDP PDF likely produce fewer changes in markers of endothelial dysfunction compared to conventional PDF in incident PD patients.

  19. FAA Fluorescent Penetrant Activities - An Update

    SciTech Connect

    Moore, D.G.

    1998-10-20

    The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently characterizing low cycle fatigue specimens that will support the needs of penetrant manufacturers, commercial airline industry and the Federal Aviation Administration. The main focus of this characterization is to maintain and enhance the evaluation of penetrant inspection materials and apply resources to support the aircraft community needs. This paper discusses efforts to-date to document the Wright Laboratory penetrant evaluation process and characterize penetrant brightness readings in the initial set of sample calibration panels using Type 1 penetrant.

  20. Management of penetrating brain injury.

    PubMed

    Kazim, Syed Faraz; Shamim, Muhammad Shahzad; Tahir, Muhammad Zubair; Enam, Syed Ather; Waheed, Shahan

    2011-07-01

    Penetrating brain injury (PBI), though less prevalent than closed head trauma, carries a worse prognosis. The publication of Guidelines for the Management of Penetrating Brain Injury in 2001, attempted to standardize the management of PBI. This paper provides a precise and updated account of the medical and surgical management of these unique injuries which still present a significant challenge to practicing neurosurgeons worldwide. The management algorithms presented in this document are based on Guidelines for the Management of Penetrating Brain Injury and the recommendations are from literature published after 2001. Optimum management of PBI requires adequate comprehension of mechanism and pathophysiology of injury. Based on current evidence, we recommend computed tomography scanning as the neuroradiologic modality of choice for PBI patients. Cerebral angiography is recommended in patients with PBI, where there is a high suspicion of vascular injury. It is still debatable whether craniectomy or craniotomy is the best approach in PBI patients. The recent trend is toward a less aggressive debridement of deep-seated bone and missile fragments and a more aggressive antibiotic prophylaxis in an effort to improve outcomes. Cerebrospinal fluid (CSF) leaks are common in PBI patients and surgical correction is recommended for those which do not close spontaneously or are refractory to CSF diversion through a ventricular or lumbar drain. The risk of post-traumatic epilepsy after PBI is high, and therefore, the use of prophylactic anticonvulsants is recommended. Advanced age, suicide attempts, associated coagulopathy, Glasgow coma scale score of 3 with bilaterally fixed and dilated pupils, and high initial intracranial pressure have been correlated with worse outcomes in PBI patients.

  1. Management of penetrating brain injury

    PubMed Central

    Kazim, Syed Faraz; Shamim, Muhammad Shahzad; Tahir, Muhammad Zubair; Enam, Syed Ather; Waheed, Shahan

    2011-01-01

    Penetrating brain injury (PBI), though less prevalent than closed head trauma, carries a worse prognosis. The publication of Guidelines for the Management of Penetrating Brain Injury in 2001, attempted to standardize the management of PBI. This paper provides a precise and updated account of the medical and surgical management of these unique injuries which still present a significant challenge to practicing neurosurgeons worldwide. The management algorithms presented in this document are based on Guidelines for the Management of Penetrating Brain Injury and the recommendations are from literature published after 2001. Optimum management of PBI requires adequate comprehension of mechanism and pathophysiology of injury. Based on current evidence, we recommend computed tomography scanning as the neuroradiologic modality of choice for PBI patients. Cerebral angiography is recommended in patients with PBI, where there is a high suspicion of vascular injury. It is still debatable whether craniectomy or craniotomy is the best approach in PBI patients. The recent trend is toward a less aggressive debridement of deep-seated bone and missile fragments and a more aggressive antibiotic prophylaxis in an effort to improve outcomes. Cerebrospinal fluid (CSF) leaks are common in PBI patients and surgical correction is recommended for those which do not close spontaneously or are refractory to CSF diversion through a ventricular or lumbar drain. The risk of post-traumatic epilepsy after PBI is high, and therefore, the use of prophylactic anticonvulsants is recommended. Advanced age, suicide attempts, associated coagulopathy, Glasgow coma scale score of 3 with bilaterally fixed and dilated pupils, and high initial intracranial pressure have been correlated with worse outcomes in PBI patients. PMID:21887033

  2. Microbial Keratitis After Penetrating Keratoplasty.

    PubMed

    Sun, Jen-Pin; Chen, Wei-Li; Huang, Jehn-Yu; Hou, Yu-Chih; Wang, I-Jong; Hu, Fung-Rong

    2017-06-01

    To report the incidence, microbiological profile, graft survival, and determining factors of microbial keratitis after penetrating keratoplasty (PK). Observational case series. The study involved 51 patients (52 eyes) who were treated at a single tertiary referral center during a 10-year period. Retrospective chart review included medical records of all patients diagnosed with microbial keratitis after penetrating keratoplasty at the National Taiwan University Hospital between January 2000 and December 2009. The main outcome measures were incidence of graft infection, microbial profile, and graft survival status. There were 871 PKs performed and 67 episodes in 52 eyes of culture-positive microbial keratitis during the study period. There were 32 infectious episodes (47.8%) in the first year post-PK and 35 episodes (52.2%) after the first year post-PK. Forty-four gram-positive bacterial isolates (57.9%), 17 gram-negative bacterial isolates (22.4%), and 15 fungal isolates (19.7%) were found. Twenty-three (34.3%) grafts remained clear after the infection episode with a mean follow-up of 1127 days (range, 25-3962 days). There was no difference in graft survival rate regarding the original indication of PK or offending pathogen. Suture-related infection was associated with decreased risk of graft failure (P = .02), while the factor associated with increased risk of graft failure was usage of antiglaucoma agents (P = .01). Infectious keratitis after penetrating keratoplasty leads to a high graft failure rate. Such complications can occur before or after the first year post-PK. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Spectrophotometric Evaluation of Potassium Nitrate Penetration Into the Pulp Cavity.

    PubMed

    Kwon, S R; Dawson, D V; Schenck, D M; Fiegel, J; Wertz, P W

    2015-01-01

    The aim of this study was to evaluate the penetration level of potassium nitrate-containing desensitizers or whitening materials into the pulp cavity with regard to the concentration and viscosity of the formulation. Fifty extracted human molar teeth were prepared and randomized into five groups of 10 specimens each. The control received a 30-minute treatment without any treatment material; the other four groups corresponded to treatment with DayWhite, a 14% hydrogen peroxide whitening material containing potassium nitrate; PreviDent 5000 Sensitive, a desensitizing toothpaste; Relief ACP, a desensitizing gel; or UltraEZ, a desensitizing gel. Potassium nitrate penetration levels were measured spectrophotometrically based on the Griess assay method. Treatment materials were measured for viscosity as a function of shear rate through the use of a cone-and-plate rheometer. Nitrate penetration levels were significantly different among the five groups (p<0.0001, Kruskal-Wallis test). After adjustment for multiple comparisons using an overall 0.05 level of type I error, the distribution of nitrate penetration values was found to differ significantly among all groups with the exception of DayWhite (median: 10.72 μM) and UltraEZ (median: 9.22 μM), which differed significantly from other groups but not from each other. The highest levels of nitrate penetration value were observed for PreviDent (median: 27.61 μM) followed by Relief ACP (median: 19.64 μM). The lowest penetration level was observed for the control group (median: 3.41 μM). Stable end-point viscosities of 11.43 ± 0.67 Pa/s, 1.33 ± 0.06 Pa/s, 0.85 ± 0.09 Pa/s, and 0.40 ± 0.01 Pa/s were observed for UltraEZ, ReliefACP, DayWhite, and PreviDent, respectively. Potassium nitrate included in different formulations can penetrate the enamel and dentin within 30 minutes. The level of potassium nitrate penetration is influenced by concentration and may also be partly affected by the viscosity of the material as well

  4. Evaluating Trichloroethylene Degradation Using Differing Nano- and Micro-Scale Iron Particles

    NASA Technical Reports Server (NTRS)

    Berger, Cristina M.; Geiger, Cherie L.; Clausen, Christian A.; Billow, Alexa M.; Quinn, Jacqueline W.; Brooks, Kathleen B.

    2006-01-01

    Trichioroethylene, or TCE, is a central nervous system depressant and possible carcinogen, as well as a persistent groundwater pollutant. TCE exists in the aquifer either as free product in the form of a dense non-aqueous phase liquid (DNAPL) or as a dissolved-phase constituent. It is only slightly soluble in water, so dissolution of the contaminant is a long-term process and in-situ remediation is difficult. To remedy this, NASA and the University of Central Florida developed Emulsified Zero-Valent Iron, or EZVI. The emulsion droplet contains ZVI particles and water encapsulated by an oil/surfactant membrane, and effectively penetrates to degrade DNAPL-phase TCE. To maximize the efficiency of this process, several commercially available ZVIs of radically different particle sizes and morphologies both in emulsion and as neat (unemulsified) metal were evaluated for relative effectiveness at TCE degradation.

  5. Pre-heating mitigates composite degradation

    PubMed Central

    da SILVA, Jessika Calixto; Rogério Vieira, REGES; REGE, Inara Carneiro Costa; CRUZ, Carlos Alberto dos Santos; VAZ, Luís Geraldo; ESTRELA, Carlos; de CASTRO, Fabrício Luscino Alves

    2015-01-01

    ABSTRACT Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey’s tests (α=5%). Results Radiopacity levels were as follows: Durafill VSpenetration into the composites ranked as follows: Durafill VS>Z-350>Z-250 (p<0.05). After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05). There was a lower penetration of silver in pre-heated specimens (p<0.05). Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth. PMID:26814459

  6. Pre-heating mitigates composite degradation.

    PubMed

    Silva, Jessika Calixto da; Rogério Vieira, Reges; Rege, Inara Carneiro Costa; Cruz, Carlos Alberto dos Santos; Vaz, Luís Geraldo; Estrela, Carlos; Castro, Fabrício Luscino Alves de

    2015-01-01

    Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey's tests (α=5%). Results Radiopacity levels were as follows: Durafill VSpenetration into the composites ranked as follows: Durafill VS>Z-350>Z-250 (p<0.05). After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05). There was a lower penetration of silver in pre-heated specimens (p<0.05). Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

  7. Method and apparatus for transport, introduction, atomization and excitation of emission spectrum for quantitative analysis of high temperature gas sample streams containing vapor and particulates without degradation of sample stream temperature

    SciTech Connect

    Eckels, D.E.; Hass, W.J.

    1989-05-30

    A sample transport, sample introduction, and flame excitation system is described for spectrometric analysis of high temperature gas streams which eliminates degradation of the sample stream by condensation losses. 4 figs.

  8. Centrifuge Modeling of Projectile Penetration in Granular Soils

    DTIC Science & Technology

    1989-04-01

    Dry test samples were prepared by slowly pouring sand into the sample container from an overhead crane. Wet test samples were prepared by separately...to rest along the top of the sample buckets fore, dry test saMple5, the impact crater was carefully excavated by hand until the top surface of the...Florida Beach Sand; MX = Soil Blend 140 Table F-2. PENETRATION TEST DATA’ - MOIST SAND Proj. Soil Dry Test G Depth Velocity2 Soil Density Moisture

  9. Cable Braid Electromagnetic Penetration Model.

    SciTech Connect

    Warne, Larry K.; Langston, William L.; Basilio, Lorena I.; Johnson, W. A.

    2015-06-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles and reciprocity for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also setup in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multipoles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinite periodic planar geometry. This is used in a simplified application of reciprocity to be able to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.

  10. A lightweight ground penetrating radar

    SciTech Connect

    Koppenjan, S.K.; Allen, C.M.; Gardner, D.; Wong, H.R.

    1998-12-31

    The detection of buried objects, particularly unexploded ordnance (UXO), has gained significant interest in the US in the late 1990s. The desire to remediate the thousands of sites worldwide has become an increasing humanitarian concern. The application of radar to this problem has received renewed attention. Bechtel Nevada, Special Technologies Laboratory (STL) has developed several frequency modulated, continuous wave (FM-CW) ground penetrating radar (GPR) units for the US Department of Energy since 1984. To meet these new technical requirements for high resolution data and UXO detection, STL is moving forward with advances to GPR technology, signal processing, and imaging with the development of an innovative system. The goal is to design and fabricate a lightweight, battery operated unit that does not require surface contact and can be operated by a novice user.

  11. Tissue Penetration of Antifungal Agents

    PubMed Central

    Felton, Timothy; Troke, Peter F.

    2014-01-01

    SUMMARY Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection. PMID:24396137

  12. ENAM Mutations with Incomplete Penetrance

    PubMed Central

    Seymen, F.; Lee, K.-E.; Koruyucu, M.; Gencay, K.; Bayram, M.; Tuna, E.B.; Lee, Z.H.; Kim, J.-W.

    2014-01-01

    Amelogenesis imperfecta (AI) is a genetic disease affecting tooth enamel formation. AI can be an isolated entity or a phenotype of syndromes. To date, more than 10 genes have been associated with various forms of AI. We have identified 2 unrelated Turkish families with hypoplastic AI and performed mutational analysis. Whole-exome sequencing identified 2 novel heterozygous nonsense mutations in the ENAM gene (c.454G>T p.Glu152* in family 1, c.358C>T p.Gln120* in family 2) in the probands. Affected individuals were heterozygous for the mutation in each family. Segregation analysis within each family revealed individuals with incomplete penetrance or extremely mild enamel phenotype, in spite of having the same mutation with the other affected individuals. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations. PMID:25143514

  13. Bodily action penetrates affective perception

    PubMed Central

    Rigutti, Sara; Gerbino, Walter

    2016-01-01

    Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

  14. Bodily action penetrates affective perception.

    PubMed

    Fantoni, Carlo; Rigutti, Sara; Gerbino, Walter

    2016-01-01

    Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer's internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer's internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

  15. In-place HEPA filter penetration test

    SciTech Connect

    Bergman, W.; Wilson, K.; Elliott, J.

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  16. The water penetration of different ventilation tubes.

    PubMed

    Ricks, Rupert G; Easto, Rachel; Reddy, Venkat M

    2016-10-01

    The insertion of middle ear ventilation tubes remains one of the most common procedures for ENT surgeons. A common concern amongst patients undergoing such procedures is the effect on their ability to partake in swimming and other water sports. Currently there is little evidence comparing the penetration ability of different water solutions encountered by swimmers. This study compares the water penetration of four different water solutions for Shah, mini-Shah, T tube and titanium bobbin ventilation tubes. A model was constructed to replicate a grommet inserted through a tympanic membrane using a syringe barrel, latex membrane and one of the ventilation tubes. Four solutions (sea water, chlorinated water, freshwater and soapy water) were then pipetted down the barrel until penetration of the tube occurred. The volume required for penetration was recorded. For all tubes soapy water was the most penetrating, followed by seawater. Titanium bobbins required significantly less of each solution for penetration. Mini-Shah grommets required significantly more of all solutions except soapy water for penetration to occur. Shah grommets were more resistant to chlorinated and sea water than T tubes. Mini-Shah grommets appear to protect against water penetration into the middle ear cleft and their use should be considered in patients who are keen water-sport enthusiasts. Furthermore, swimmers in sea or chlorinated water seem to be at higher risk than freshwater swimmers. Titanium bobbins were relatively easily penetrated by all four solutions and should be avoided in keen swimmers.

  17. Highly penetrative, drug-loaded nanocarriers improve treatment of glioblastoma.

    PubMed

    Zhou, Jiangbing; Patel, Toral R; Sirianni, Rachael W; Strohbehn, Garth; Zheng, Ming-Qiang; Duong, Nha; Schafbauer, Thomas; Huttner, Anita J; Huang, Yiyun; Carson, Richard E; Zhang, Ying; Sullivan, David J; Piepmeier, Joseph M; Saltzman, W Mark

    2013-07-16

    Current therapy for glioblastoma multiforme is insufficient, with nearly universal recurrence. Available drug therapies are unsuccessful because they fail to penetrate through the region of the brain containing tumor cells and they fail to kill the cells most responsible for tumor development and therapy resistance, brain cancer stem cells (BCSCs). To address these challenges, we combined two major advances in technology: (i) brain-penetrating polymeric nanoparticles that can be loaded with drugs and are optimized for intracranial convection-enhanced delivery and (ii) repurposed compounds, previously used in Food and Drug Administration-approved products, which were identified through library screening to target BCSCs. Using fluorescence imaging and positron emission tomography, we demonstrate that brain-penetrating nanoparticles can be delivered to large intracranial volumes in both rats and pigs. We identified several agents (from Food and Drug Administration-approved products) that potently inhibit proliferation and self-renewal of BCSCs. When loaded into brain-penetrating nanoparticles and administered by convection-enhanced delivery, one of these agents, dithiazanine iodide, significantly increased survival in rats bearing BCSC-derived xenografts. This unique approach to controlled delivery in the brain should have a significant impact on treatment of glioblastoma multiforme and suggests previously undescribed routes for drug and gene delivery to treat other diseases of the central nervous system.

  18. Neoclassical toroidal viscosity and error-field penetration in tokamaks

    NASA Astrophysics Data System (ADS)

    Cole, Andrew

    2007-11-01

    A model for field error penetration is developed that includes both resonant and non-resonant perturbed 3-D magnetic fields [1]. The non-resonant components give rise to a global neoclassical toroidal viscous [NTV] torque while a single resonant component produces a localized electromagnetic braking torque on its respective resonant surface. The NTV torque tries to keep the plasma flowing at a rate comparable to the ion diamagnetic flow. A phenomenological cross-field viscosity is included which resists the resonant electromagnetic torque in the vicinity of the resonant surface. Steady-state toroidal momentum balance across the resonant layer gives a solubility condition determining the ``critical'' resonant error-field strength---termed the penetration threshold---above which rotational shielding is lost and the resonant surface locks to the lab frame. Such locking occurs in low-density start-up tokamak plasmas [2], leading to plasma disruptions or confinement degradation and is a key issue for ITER. The toroidal momentum balance equation admits a WKB-type solution which implies that NTV acts to enhance cross-field viscosity in the vicinity of the resonant surface. This enhancement makes the plasma less sensitive to error-field penetration than previously predicted [3]. In particular, if τEne (neo-Alcator-like) and the perpendicular momentum confinement time has no density dependence, we find the penetration threshold scales linearly with electron density---a result giving quantitative agreement for the first time between theory and experiment [2]. [1] A.J. Cole, C.C. Hegna, and J.D. Callen, to be published in PRL (2007). [2] S.M. Wolfe, I.R. Hutchinson, et al., Phys. Plasmas 12, 056110 (2005) and refs. cited therein. [3] A.J. Cole and R. Fitzpatrick, Phys. Plasmas 13, 032503 (2006) and refs. cited therein.

  19. Protease-degradable electrospun fibrous hydrogels

    NASA Astrophysics Data System (ADS)

    Wade, Ryan J.; Bassin, Ethan J.; Rodell, Christopher B.; Burdick, Jason A.

    2015-03-01

    Electrospun nanofibres are promising in biomedical applications to replicate features of the natural extracellular matrix (ECM). However, nearly all electrospun scaffolds are either non-degradable or degrade hydrolytically, whereas natural ECM degrades proteolytically, often through matrix metalloproteinases. Here we synthesize reactive macromers that contain protease-cleavable and fluorescent peptides and are able to form both isotropic hydrogels and electrospun fibrous hydrogels through a photoinitiated polymerization. These biomimetic scaffolds are susceptible to protease-mediated cleavage in vitro in a protease dose-dependent manner and in vivo in a subcutaneous mouse model using transdermal fluorescent imaging to monitor degradation. Importantly, materials containing an alternate and non-protease-cleavable peptide sequence are stable in both in vitro and in vivo settings. To illustrate the specificity in degradation, scaffolds with mixed fibre populations support selective fibre degradation based on individual fibre degradability. Overall, this represents a novel biomimetic approach to generate protease-sensitive fibrous scaffolds for biomedical applications.

  20. Polysaccharide Degradation

    NASA Astrophysics Data System (ADS)

    Stone, Bruce A.; Svensson, Birte; Collins, Michelle E.; Rastall, Robert A.

    An overview of current and potential enzymes used to degrade polysaccharides is presented. Such depolymerases are comprised of glycoside hydrolases, glycosyl transferases, phosphorylases and lyases, and their classification, active sites and action patterns are discussed. Additionally, the mechanisms that these enzymes use to cleave glycosidic linkages is reviewed as are inhibitors of depolymerase activity; reagents which react with amino acid residues, glycoside derivatives, transition state inhibitors and proteinaceous inhibitors. The characterization of various enzymes of microbial, animal or plant origin has led to their widespread use in the production of important oligosaccharides which can be incorporated into food stuffs. Sources of polysaccharides of particular interest in this chapter are those from plants and include inulin, dextran, xylan and pectin, as their hydrolysis products are purported to be functional foods in the context of gastrointestinal health. An alternative use of degraded polysaccharides is in the treatment of disease. The possibility exists to treat bacterial exopolysaccharide with lyases from bacteriophage to produce oligosaccharides exhibiting bioactive sequences. Although this area is currently in its infancy the knowledge is available to investigate further.

  1. Ground Penetrating Radar in Hydrogeophysics

    SciTech Connect

    Hubbard, Susan; Lambot, S.; Binley, A.; Slob, E.; Hubbard, S.

    2008-01-15

    To meet the needs of a growing population and to provide us with a higher quality of life, increasing pressures are being placed on our environment through the development of agriculture, industry, and infrastructures. Soil erosion, groundwater depletion, salinization, and pollution have been recognized for decades as major threats to ecosystems and human health. More recently, the progressive substitution of fossil fuels by biofuels for energy production and climate change have been recognized as potential threats to our water resources and sustained agricultural productivity. The vadose zone mediates many of the processes that govern water resources and quality, such as the partition of precipitation into infiltration and runoff , groundwater recharge, contaminant transport, plant growth, evaporation, and energy exchanges between the Earth's surface and its atmosphere. It also determines soil organic carbon sequestration and carbon-cycle feedbacks, which could substantially impact climate change. The vadose zone's inherent spatial variability and inaccessibility precludes direct observation of the important subsurface processes. In a societal context where the development of sustainable and optimal environmental management strategies has become a priority, there is a strong prerequisite for the development of noninvasive characterization and monitoring techniques of the vadose zone. In particular, hydrogeophysical approaches applied at relevant scales are required to appraise dynamic subsurface phenomena and to develop optimal sustainability, exploitation, and remediation strategies. Among existing geophysical techniques, ground penetrating radar (GPR) technology is of particular interest for providing high-resolution subsurface images and specifically addressing water-related questions. Ground penetrating radar is based on the transmission and reception of VHF-UHF (30-3000 MHz) electromagnetic waves into the ground, whose propagation is determined by the soil

  2. Surface keratopathy after penetrating keratoplasty.

    PubMed

    Feiz, V; Mannis, M J; Kandavel, G; McCarthy, M; Izquierdo, L; Eckert, M; Schwab, I R; Torabian, S; Wang, J L; Wang, W

    2001-01-01

    To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium. Prospective cohort study. We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy. Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also associated with an increased

  3. Surface keratopathy after penetrating keratoplasty.

    PubMed Central

    Feiz, V; Mannis, M J; Kandavel, G; McCarthy, M; Izquierdo, L; Eckert, M; Schwab, I R; Torabian, S; Wang, J L; Wang, W

    2001-01-01

    PURPOSE: To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium. DESIGN: Prospective cohort study. METHODS: We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy. RESULTS: Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also

  4. Social Penetration: A Description, Research, and Evaluation.

    ERIC Educational Resources Information Center

    Allensworth, Nicole J.

    Social penetration has been described by S.W. Littlejohn (1992) as "the process of increasing disclosure and intimacy in a relationship." The phrase "social penetration" originated with I. Altman and D. Taylor, the foremost researchers in this area. From other theories, Altman and Taylor developed a unified theory which…

  5. Tungsten-uranium penetrator target interaction

    NASA Astrophysics Data System (ADS)

    Dunn, P. S.; Damkroger, B. K.

    Several studies performed in recent years have been directed at determining the penetration mechanism of long rod kinetic energy penetrators into Rolled Homogeneous Armor (RHA). Much of the work has centered on comparing U-0.75Ti and Tungsten Heavy Alloys (WHA), with the goal being to relate the superior ballistic performance of the uranium materials to a fundamental difference in penetration mechanisms. This has been found to be true, with the dominant mechanisms being adiabatic shear in U-0.75Ti and bulk deformation in WHA. Recent work has sought to achieve improvements in the ballistic performance of the tungsten materials via both mechanical property improvements and alloy modifications designed to bring about adiabatic shear. As an alternative, the authors propose the consideration of materials which utilize mechanisms other than bulk deformation and adiabatic shear to optimize ballistic performance. This paper will present the postmortem analysis of a uranium-20 vol% tungsten composite penetrator fired into RHA at 0 degree obliquity. The analysis shows that the penetration mechanism in this material is bulk heating and extensive co-melting of the target and penetrator at the penetration interface. The results of the analysis will then be compared to a similar analysis made of targets into which U-0.75Ti penetrators had been fired.

  6. FRACTIONAL PENETRATION OF PAINT OVERSPRAY ARRESTORS

    EPA Science Inventory

    The report describes the development of fractional penetration curves for liquid droplet penetration of overspray arrestors for discrete droplet diameters from 0.3 to 10 micrometers. (NOTE: Fine particulates are particles with diameters of 10 micrometers or less.) These data poin...

  7. Fluorescent penetration enhancers for transdermal applications.

    PubMed

    Seto, Jennifer E; Polat, Baris E; VanVeller, Brett; Lopez, Renata F V; Langer, Robert; Blankschtein, Daniel

    2012-02-28

    Chemical penetration enhancers are often used to enhance transdermal drug delivery. However, the fundamental mechanisms that govern the interactions between penetration enhancers and skin are not fully understood. Therefore, the goal of this work was to identify naturally fluorescent penetration enhancers (FPEs) in order to utilize well-established fluorescence techniques to directly study the behavior of FPEs within skin. In this study, 12 fluorescent molecules with amphiphilic characteristics were evaluated as skin penetration enhancers. Eight of the molecules exhibited significant activity as skin penetration enhancers, determined using skin current enhancement ratios. In addition, to illustrate the novel, direct, and non-invasive visualization of the behavior of FPEs within skin, three case studies involving the use of two-photon fluorescence microscopy (TPM) are presented, including visualizing glycerol-mitigated and ultrasound-enhanced FPE skin penetration. Previous TPM studies have indirectly visualized the effect of penetration enhancers on the skin by using a fluorescent dye to probe the transdermal pathways of the enhancer. These effects can now be directly visualized and investigated using FPEs. Finally, future studies are proposed for generating FPE design principles. The combination of FPEs with fluorescence techniques represents a useful novel approach for obtaining physical insights on the behavior of penetration enhancers within the skin. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Fluorescent Penetration Enhancers for Transdermal Applications

    PubMed Central

    Seto, Jennifer E.; Polat, Baris E.; VanVeller, Brett; Lopez, Renata F.V.; Langer, Robert; Blankschtein, Daniel

    2011-01-01

    Chemical penetration enhancers are often used to enhance transdermal drug delivery. However, the fundamental mechanisms that govern the interactions between penetration enhancers and skin are not fully understood. Therefore, the goal of this work was to identify naturally fluorescent penetration enhancers (FPEs) in order to utilize well-established fluorescence techniques to directly study the behavior of FPEs within skin. In this study, 12 fluorescent molecules with amphiphilic characteristics were evaluated as skin penetration enhancers. Eight of the molecules exhibited significant activity as skin penetration enhancers, determined using skin current enhancement ratios. In addition, to illustrate the novel, direct, and non-invasive visualization of the behavior of FPEs within skin, three case studies involving the use of two-photon fluorescence microscopy (TPM) are presented, including visualizing glycerol-mitigated and ultrasound-enhanced FPE skin penetration. Previous TPM studies have indirectly visualized the effect of penetration enhancers on skin by using a fluorescent dye to probe the transdermal pathways of the enhancer. These effects can now be directly visualized and investigated using FPEs. Finally, future studies are proposed for generating FPE design principles. The combination of FPEs with fluorescence techniques represents a useful novel approach for obtaining physical insights on the behavior of penetration enhancers within skin. PMID:22062691

  9. FRACTIONAL PENETRATION OF PAINT OVERSPRAY ARRESTORS

    EPA Science Inventory

    The report describes the development of fractional penetration curves for liquid droplet penetration of overspray arrestors for discrete droplet diameters from 0.3 to 10 micrometers. (NOTE: Fine particulates are particles with diameters of 10 micrometers or less.) These data poin...

  10. Post-penetrating keratoplasty glaucoma

    PubMed Central

    Aggarwal, Anand; Minudath, KB; Vanathi, M; Choudhary, Sunil; Gupta, Viney; Sihota, Ramanjit; Panda, Anita

    2008-01-01

    Post-penetrating keratoplasty (post-PK) glaucoma is an important cause of irreversible visual loss and graft failure. The etiology for this disorder is multifactorial, and with the use of new diagnostic equipment, it is now possible to elucidate the exact pathophysiology of this condition. A clear understanding of the various mechanisms that operate during different time frames following PK is essential to chalk out the appropriate management algorithms. The various issues with regard to its management, including the putative risk factors, intraocular pressure (IOP) assessment post-PK, difficulties in monitoring with regard to the visual fields and optic nerve evaluation, are discussed. A step-wise approach to management starting from the medical management to surgery with and without metabolites and the various cycloablative procedures in cases of failed filtering procedures and excessive perilimbal scarring is presented. Finally, the important issue of minimizing the incidence of glaucoma following PK, especially through the use of oversized grafts and iris tightening procedures in the form of concomitant iridoplasty are emphasized. It is important to weigh the risk-benefit ratio of any modality used in the treatment of this condition as procedures aimed at IOP reduction, namely trabeculectomy with antimetabolites, and glaucoma drainage devices can trigger graft rejection, whereas cyclodestructive procedures can not only cause graft failure but also precipitate phthisis bulbi. Watchful expectancy and optimal time of intervention can salvage both graft and vision in this challenging condition. PMID:18579984

  11. Stepped frequency ground penetrating radar

    DOEpatents

    Vadnais, Kenneth G.; Bashforth, Michael B.; Lewallen, Tricia S.; Nammath, Sharyn R.

    1994-01-01

    A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass filter. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.

  12. Grepafloxacin: pharmacokinetics and tissue penetration.

    PubMed

    Wise, Richard

    1998-03-01

    Pharmacokinetic and tissue penetration studies of grepafloxacin, a new broad-spectrum fluoroquinolone, show that it has useful properties for the treatment of respiratory tract infections. Grepafloxacin has a volume of distribution that is larger than those of many of the other fluoroquinolones and is concentrated in alveolar macrophages, bronchial mucosa and epithelial lining fluid to a greater extent than are certain other fluoroquinolones. Grepafloxacin concentrations achieved in plasma after a 400-mg oral dose are well in excess of those required to inhibit the respiratory pathogens Staphylococcus aureus, Haemophilus influenzae and Moraxella catarrhalis. Streptococcus pneumoniae is also covered for most of the dosing interval, but at normal dose levels grepafloxacin might not inhibit Enterococcus faecalis. The maximum plasma concentrations and area under the concentration---time curve achieved with grepafloxacin suggest that it will be effective for the treatment of community-acquired pneumonia and acute exacerbations of chronic bronchitis. The pharmacokinetics of fluoroquinolones are among their most useful properties. The aim of this paper is to demonstrate whether the differences between grepafloxacin and the other fluoroquinolones are of therapeutic significance.

  13. Penetrating Wounds of Great Vessels

    PubMed Central

    Symbas, P. N.; Kourias, E.; Tyras, D. H.; Hatcher, C. R.

    1974-01-01

    Thirty-six patients with penetrating wounds of the great vessels treated at Grady Memorial Hospital during a 7-year period were reviewed. In more than 50% of the cases, diagnosis of the injury was made at the time of emergency thoracotomy for massive bleeding. In the remaining patients the diagnosis was suspected: 1) when the pulse distal to the vascular injury was absent or weak; 2) when the patient had symptoms and signs of impaired central nervous system perfusion; 3) when the missile had traversed the mediastinum and there was roentgenographic evidence of widening of the mediastinal shadow; or, 4) when a new murmur appeared. In all suspected cases with great vessel injury, the diagnosis was confirmed arteriographically. Arteriography in such patients should be performed to define the type and site of vascular injury so that its repair can be properly planned. Twenty-nine patients recovered from their injury, 6 succumbed as a result of it and 1 required midforearm amputation following repair of a subclavian artery and vein injury. Most of these patients underwent autotransfusion which greatly contributed to their successful outcome. Local temporary shunt was used for protection of the spinal cord and/or brain when impairment of their perfusion was required for the repair of the vascular wounds. ImagesFig. 1.Fig. 3.Fig. 4. PMID:17859862

  14. Analytical review of 664 cases of penetrating buttock trauma

    PubMed Central

    2011-01-01

    A comprehensive review of data has not yet been provided as penetrating injury to the buttock is not a common condition accounting for 2-3% of all penetrating injuries. The aim of the study is to provide the as yet lacking analytical review of the literature on penetrating trauma to the buttock, with appraisal of characteristics, features, outcomes, and patterns of major injuries. Based on these results we will provide an algorithm. Using a set of terms we searched the databases Pub Med, EMBASE, Cochran, and CINAHL for articles published in English between 1970 and 2010. We analysed cumulative data from prospective and retrospective studies, and case reports. The literature search revealed 36 relevant articles containing data on 664 patients. There was no grade A evidence found. The injury population mostly consists of young males (95.4%) with a high proportion missile injury (75.9%). Bleeding was found to be the key problem which mostly occurs from internal injury and results in shock in 10%. Overall mortality is 2.9% with significant adverse impact of visceral or vascular injury and shock (P < 0.001). The major injury pattern significantly varies between shot and stab injury with small bowel, colon, or rectum injuries leading in shot wounds, whilst vascular injury leads in stab wounds (P < 0.01). Laparotomy was required in 26.9% of patients. Wound infection, sepsis or multiorgan failure, small bowel fistula, ileus, rebleeding, focal neurologic deficit, and urinary tract infection were the most common complications. Sharp differences in injury pattern endorse an algorithm for differential therapy of penetrating buttock trauma. In conclusion, penetrating buttock trauma should be regarded as a life-threatening injury with impact beyond the pelvis until proven otherwise. PMID:21995834

  15. Sufficient penetration of peracetic acid into drilled human femoral heads.

    PubMed

    Brosig, H; Jacker, H-J; Borchert, H-H; Kalus, U; Dörner, T; von Versen, R; Pruss, A

    2005-01-01

    Chemical sterilisation methods for musculoskeletal transplants have the problem of penetration into all tissue strata. The present study examined if a peracetic acid/ethanol solution penetrated to a sufficient extent into specifically prepared femoral heads. To this effect, 10 femoral heads have been provided with drillings (diameter 2 mm, depth 10 mm) at a distance of 15 mm (series B) and placed in a diffusion chamber with sterilisation solution. From an additional central drilling at the femoral neck junction, the sample drawing was made after 30 min each over a period of 4 h for the iodometric determination of peracetic acid (PAA) concentration. Ten femoral heads, which did contain only the central drilling, served as controls (series A). In 9 of the examined femoral heads of series A the defined minimum concentration of PAA of 0.2% (inactivation of bacteria, spores, fungi) has been clearly exceeded over the complete period of measurement. About 0.8% PAA (inactivation of viruses) was achieved within 4 h only with six femoral heads. Nine out of the 10 examined femoral heads in series B show a clearly improved penetration behaviour which was expressed in smaller standard deviations, a faster increase in concentration, as well as in higher starting and final concentrations (approx. 0.9%) of PAA. Previous drying in air leads to a faster penetration into the centre of the bone. Standardised drilling of de-cartilaged femoral heads creates favourable conditions for the penetration of the PAA sterilisation solution into the whole tissue and guarantees a sufficient inactivation of microorganisms.

  16. Penetration of aflatoxins through isolated human epidermis

    SciTech Connect

    Riley, R.T.; Kemppainen, B.W.; Norred, W.P.

    1985-01-01

    The purpose of this study was to determine if aflatoxin B1 (AFB1) could penetrate through isolated human epidermis (stratum corneum plus viable epidermis). ( UC)AFB1 (7.5-9.3 micrograms) was applied to the stratum corneum of epidermal disks mounted in Teflon diffusion cells. ( UC)AFB1 penetrated chemically unaltered through the isolated epidermis. Chloroform-extractable radioactivity accounted for 82.5 +/- 3.7% of the total penetrating radioactivity in the receptor fluid of the diffusion cells. The rate of penetration was very slow when experiments were conducted under nonoccluded conditions, but was approximately 40 times greater under conditions of occlusion. Penetration after 46 h was less than 0.05% and 3.41% of the applied dose under nonoccluded and occluded conditions, respectively. Total recovery expressed as a percentage of the applied radioactivity was 98.6 +/- 6.4%.

  17. MYC Degradation

    PubMed Central

    Farrell, Amy S.; Sears, Rosalie C.

    2014-01-01

    The MYC oncoprotein is an essential transcription factor that regulates the expression of many genes involved in cell growth, proliferation, and metabolic pathways. Thus, it is important to keep MYC activity in check in normal cells in order to avoid unwanted oncogenic changes. Normal cells have adapted several ways to control MYC levels, and these mechanisms can be disrupted in cancer cells. One of the major ways in which MYC levels are controlled in cells is through targeted degradation by the ubiquitin–proteasome system (UPS). Here, we discuss the role of the UPS in the regulation of MYC protein levels and review some of the many proteins that have been shown to regulate MYC protein stability. In addition, we discuss how this relates to MYC transcriptional activity, human cancers, and therapeutic targeting. PMID:24591536

  18. Penetration of lycopsamine from a comfrey ointment through human epidermis.

    PubMed

    Jedlinszki, Nikoletta; Balázs, Boglárka; Csányi, Erzsébet; Csupor, Dezső

    2017-02-01

    Mutagenic and teratogenic pyrrolizidine alkaloids (PAs) have been identified in several plant species. The industrially most important PA-containing plant is Symphytum officinale (common comfrey). The application of its root is restricted in several countries due to its PA content. In medicines, the daily alkaloid quantity and duration of treatment may be limited even in case of topical application. Due to the confirmed good absorption of PAs from the gastrointestinal tract, the prohibition of oral use is justified, however the limitation of external application is not supported by relevant data. Penetration experiments on human skin are not available to be a rational basis for limitation. The aim of our work was to carry out pharmacokinetic studies on the diffusion and penetration of lycopsamine (a main PA of comfrey) from a Symphytum product through a synthetic membrane and human skin. Investigations were carried out on vertical Franz diffusion cell and lycopsamine was quantified by a validated LC-MS method. The amount of lycopsamine diffused through a synthetic membrane varied between 0.11% and 0.72% (within 24 h). On human epidermis, the rate of penetration was lower (0.04-0.22%). Our results may contribute to the more realistic toxicological assessment of externally applied PA-containing products.

  19. Comparison of rates of general corrosion and maximum pitting penetration on concrete embedded steel reinforcement

    SciTech Connect

    Gonzalez, J.A.; Feliu, S. ); Andrade, C.; Alonso, C. )

    1995-02-01

    Local attack of reinforcement is observed usually in chloride-contaminated concrete. When mechanical weakening of the concrete structure is affected by the bar section loss in the places where corrosion is intensified, the maximum penetration of the deepest pits happens to be a very relevant datum. In this work average corrosion values are compared with maximum pit depth values. Using natural corrosion tests and accelerated tests, it has been found that the maximum penetration of localized attack on steel embedded in concrete containing chlorides is equivalent to about four to eight times the average general penetration.

  20. Response of Earth Penetrator Structures in Angle-of-Attack Impacts

    DTIC Science & Technology

    1977-06-01

    decelerates by impacting the energy-absorbing aluminum honeycomb. Experimental Setup To simulate the load on a penetrator that impacts at an angle of attack...absorber ( aluminum honeycomb or Styrofoam) located in a 5-foot-long (1.52-m-long) safety shroud. The shroud ensures containment of the model. penetrator...uniform cross section (except at the loaded hemispherical end). The solid aluminum model is geometrically identical to the solid steel model but is made

  1. Penetrating radiation: applications at Los Alamos National Laboratory

    NASA Astrophysics Data System (ADS)

    Watson, Scott; Hunter, James; Morris, Christopher

    2013-09-01

    Los Alamos has used penetrating radiography extensively throughout its history dating back to the Manhattan Project where imaging dense, imploding objects was the subject of intense interest. This interest continues today as major facilities like DARHT1 have become the mainstay of the US Stockpile Stewardship Program2 and the cornerstone of nuclear weapons certification. Meanwhile, emerging threats to national security from cargo containers and improvised explosive devices (IEDs) have invigorated inspection efforts using muon tomography, and compact x-ray radiography. Additionally, unusual environmental threats, like those from underwater oil spills and nuclear power plant accidents, have caused renewed interest in fielding radiography in severe operating conditions. We review the history of penetrating radiography at Los Alamos and survey technologies as presently applied to these important problems.

  2. Reliability Analysis of Penetration Systems Using Nondeterministic Methods

    SciTech Connect

    FIELD JR.,RICHARD V.; PAEZ,THOMAS L.; RED-HORSE,JOHN R.

    1999-10-27

    Device penetration into media such as metal and soil is an application of some engineering interest. Often, these devices contain internal components and it is of paramount importance that all significant components survive the severe environment that accompanies the penetration event. In addition, the system must be robust to perturbations in its operating environment, some of which exhibit behavior which can only be quantified to within some level of uncertainty. In the analysis discussed herein, methods to address the reliability of internal components for a specific application system are discussed. The shock response spectrum (SRS) is utilized in conjunction with the Advanced Mean Value (AMV) and Response Surface methods to make probabilistic statements regarding the predicted reliability of internal components. Monte Carlo simulation methods are also explored.

  3. Time Course of Potassium Nitrate Penetration into the Pulp Cavity and the Effect of Penetration Levels on Tooth Whitening Efficacy.

    PubMed

    Kwon, So Ran; Dawson, Deborah V; Wertz, Philip W

    2016-03-01

    To establish time-course of potassium nitrate (PN) penetration into the pulp cavity, and determine whether PN pretreatment would affect whitening efficacy. Extracted teeth (n = 100) were randomized into five groups of 20 specimens each. Relief ACP (Philips Oral Healthcare, Los Angeles, CA, USA) was applied for 0, 5, 15, 30, and 60 minutes for groups 15, respectively. A nitrate/nitrite assay kit was used for colorimetric detection of nitrate. Whitening was performed using a Zoom White Speed system (Philips Oral Healthcare) for 60 minutes. Tooth color was measured with a spectrophotometer at baseline (T0 ), 1-day post PN application (T1 ), 1-day post-whitening (T2 ), and 1-month post-whitening (T3 ). Kruskal-Wallis test was used to assess group differences in PN penetration and tooth color change. PN penetration differed among all groups except 2 and 3. There were no differences among groups for any baseline color parameters (p > 0.30). At T2 there was no change relative to baseline for individual components L*, a*, and b*. At T3 and T4 there was significant change relative to baseline for ΔL*, Δb*, and ΔE*, for all groups. PN penetration is time dependent and pretreatment with PN does not affect whitening efficacy. Postassium nitrate penetration into the pulp cavity occurred as early as 5 minutes after application, and pretreatment with potassium nitrate containing desensitizers did not adversely affect tooth whitening efficacy. (J Esthet Restor Dent 28:S14-S22, 2016). © 2016 Wiley Periodicals, Inc.

  4. Military penetrating spine injuries compared with blunt.

    PubMed

    Blair, James A; Possley, Daniel R; Petfield, Joseph L; Schoenfeld, Andrew J; Lehman, Ronald A; Hsu, Joseph R

    2012-09-01

    The nature of blunt and penetrating injuries to the spine and spinal column in a military combat setting has been poorly documented in the literature. To date, no study has attempted to characterize and compare blunt and penetrating spine injuries sustained by American servicemembers. The purpose of this study was to compare the military penetrating spine injuries with blunt spine injuries in the current military conflicts. Retrospective study. All American military servicemembers who have been injured while deployed in Iraq (Operation Iraqi Freedom) and Afghanistan (Operation Enduring Freedom) whose medical data have been entered into the Joint Theater Trauma Registry (JTTR). The JTTR was queried for all American servicemembers sustaining an injury to the spinal column or spinal cord while deployed in Iraq or Afghanistan. These data were manually reviewed for relevant information regarding demographics, mechanism of injury, surgical intervention, and neurologic injury. A total of 598 servicemembers sustained injuries to the spine or spinal cord. Isolated blunt injuries were recorded in 396 (66%) servicemembers and 165 (28%) sustained isolating penetrating injuries. Thirty servicemembers (5%) sustained combined blunt and penetrating injuries to the spine. The most commonly documented injuries were transverse process fractures, compression fractures, and burst fractures in the blunt-injured servicemembers versus transverse process fractures, lamina fractures, and spinous process fractures in those injured with a penetrating injury. One hundred four (17%) servicemembers sustained spinal cord injuries, comprising 10% of blunt injuries and 38% of penetrating injuries (p<.0001). Twenty-eight percent (28%) of blunt-injured servicemembers underwent a surgical procedure compared with 41% of those injured by penetrating mechanisms (p=.4). Sixty percent (n=12/20) of blunt-injured servicemembers experienced a neurologic improvement after surgical intervention at follow

  5. Penetrating palpebral grass awn in a dog: Unusual case of a penetrating grass awn in an eyelid.

    PubMed

    Marchegiani, Andrea; Fruganti, Alessandro; Cerquetella, Matteo; Cassarani, Maria Paola; Laus, Fulvio; Spaterna, Andrea

    2017-03-01

    An unusual case of a penetrating grass awn in an eyelid of a dog is reported. A 6-month-old mixed breed dog was referred to the Ophthalmology Unit of the Veterinary Teaching Hospital of Camerino University for anorexia, lethargy, left monolateral ocular swelling and pain to the left eye, present from 1 month. Ophthalmic examination of the left eye showed copious and purulent discharge, and ultrasonography revealed the presence of an abscess containing a grass foreign body. The grass awn was surgically removed. Three days after surgery, the dog showed a marked improvement, with a total resolution obtained in 7 days. To the authors' knowledge, penetrating foreign bodies such as the one of this paper have never been described before in literature.

  6. Modeling pollutant penetration across building envelopes

    SciTech Connect

    Liu, De-Ling; Nazaroff, William W.

    2001-04-01

    As air infiltrates through unintentional openings in building envelopes, pollutants may interact with adjacent surfaces. Such interactions can alter human exposure to air pollutants of outdoor origin. We present modeling explorations of the proportion of particles and reactive gases (e.g., ozone) that penetrate building envelopes as air enters through cracks and wall cavities. Calculations were performed for idealized rectangular cracks, assuming regular geometry, smooth inner crack surface and steady airflow. Particles of 0.1-1.0 {micro}m diameter are predicted to have the highest penetration efficiency, nearly unity for crack heights of 0.25 mm or larger, assuming a pressure difference of 4 Pa or greater and a flow path length of 3 cm or less. Supermicron and ultrafine particles are significantly removed by means of gravitational settling and Brownian diffusion, respectively. In addition to crack geometry, ozone penetration depends on its reactivity with crack surfaces, as parameterized by the reaction probability. For reaction probabilities less than {approx}10{sup -5}, penetration is complete for cracks heights greater than 1 mm. However, penetration through mm scale cracks is small if the reaction probability is {approx}10{sup -4} or greater. For wall cavities, fiberglass insulation is an efficient particle filter, but particles would penetrate efficiently through uninsulated wall cavities or through insulated cavities with significant airflow bypass. The ozone reaction probability on fiberglass fibers was measured to be 10{sup -7} for fibers previously exposed to high ozone levels and 6 x 10{sup -6} for unexposed fibers. Over this range, ozone penetration through fiberglass insulation would vary from >90% to {approx}10-40%. Thus, under many conditions penetration is high; however, there are realistic circumstances in which building envelopes can provide substantial pollutant removal. Not enough is yet known about the detailed nature of pollutant penetration

  7. Penetration and distribution of thiocolchicoside through human skin: comparison between a commercial foam (Miotens) and a drug solution.

    PubMed

    Aguzzi, Carola; Rossi, Silvia; Bagnasco, Michela; Lanata, Luigi; Sandri, Giuseppina; Bona, Fosca; Ferrari, Franca; Bonferoni, Maria Cristina; Caramella, Carla

    2008-01-01

    Penetration and distribution of thiocolchicoside from a commercially available foam (Miotens 0.25%, w/v) through human excised full-thickness skin were evaluated using two different in vitro apparatus: a Franz diffusion cell and a Saarbruecken penetration model-based cell. In order to evaluate the intrinsic capability of the drug to penetrate into the skin, a simple drug aqueous solution prepared at the same drug concentration as Miotens was also tested. Results showed that both apparatus were suitable to study thiocolchicoside penetration into human skin. Penetrated drug amounts were comparable using the two apparatus, probably because skin acts as "sink" for the drug. Miotens was found to significantly promote thiocolchicoside accumulation into full human skin thickness in comparison with the simple drug solution. The mixture of propylene glycol and propylene glycol diperlargonate contained into Miotens foam has been proven to be effective to promote penetration of thiocolchicoside into human skin.

  8. Penetrating Orbital Injury From a Needlefish.

    PubMed

    Miller, Kyle E; Coan, Erin B

    2016-08-01

    Orbital penetrating injuries are an unfortunately common occurrence; however, those from marine animals are rare. Injuries from marine animals can be quite profound and there are no known reports of complete visual recovery after an orbital penetrating injury. Complications range from secondary infection to a carotid-cavernous fistula, which can complicate the management of these patients. We report a case of penetrating orbital injury from a needlefish with complete return of visual function after surgical removal of foreign debris and an extended course of antibiotics. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

  9. Aqueous marker penetration into ion irradiated polyimide

    NASA Astrophysics Data System (ADS)

    Fink, D.; Müller, M.; Petrov, A.; Klett, R.; Palmetshofer, L.; Hnatowicz, V.; Vacik, J.; Cervena, J.; Chadderton, L. T.

    2002-05-01

    The penetration of aqueous 6Li + markers into low energy ion irradiated polyimide (PI) foils was examined by the neutron depth profiling technique in combination with a modified tomographic approach. The ion irradiation always leads to an enhancement in marker uptake. After irradiation at low fluence the marker profiles follow the nuclear damage distribution even in three dimensions. At elevated fluences saturation in the marker uptake is clearly seen. The polymer's penetrant uptake can be described well by regular diffusion, with nuclear damage centres acting as saturable traps. These observations are strikingly different from the marker penetration into high-energy heavy-ion irradiated PI.

  10. Earthquakes induced by deep penetrating bombing?

    NASA Astrophysics Data System (ADS)

    Balassanian, Serguei Y.

    2005-11-01

    The data of M≥5 earthquakes occurred in one year before and after 4 deep penetrating bombs in the region within 500 km and 1 000 km from the shooting site are presented. The 4 bombs are those happened in 1999 Kosovo of Yugoslavia, the 1991 Baghdad of Iraq, the 2001 Tora Bora of Afghanistan, and the 2003 Kirkuk of Iraq, respectively. The data indicate that the deep penetrating bombs may have remotely triggered some earthquakes. The deep penetrating bombs in seismically active regions should be forbidden.

  11. Sphere impact and penetration into wet sand.

    PubMed

    Marston, J O; Vakarelski, I U; Thoroddsen, S T

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  12. Sphere impact and penetration into wet sand

    NASA Astrophysics Data System (ADS)

    Marston, J. O.; Vakarelski, I. U.; Thoroddsen, S. T.

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  13. Pressure enhanced penetration with shaped charge perforators

    DOEpatents

    Glenn, Lewis A.

    2001-01-01

    A downhole tool, adapted to retain a shaped charge surrounded by a superatmospherically pressurized light gas, is employed in a method for perforating a casing and penetrating reservoir rock around a wellbore. Penetration of a shaped charge jet can be enhanced by at least 40% by imploding a liner in the high pressure, light gas atmosphere. The gas pressure helps confine the jet on the axis of penetration in the latter stages of formation. The light gas, such as helium or hydrogen, is employed to keep the gas density low enough so as not to inhibit liner collapse.

  14. Miniature Ground Penetrating Radar, CRUX GPR

    NASA Technical Reports Server (NTRS)

    Kim, Soon Sam; Carnes, Steven R.; Haldemann, Albert F.; Ulmer, Christopher T.; Ng, Eddie; Arcone, Steven A.

    2006-01-01

    Under NASA instrument development programs (PIDDP 2000-2002, MIPD 2003-2005, ESR and T, 2005) we have been developing miniature ground penetrating radars (GPR) for use in mapping subsurface stratigraphy from planetary rovers for Mars and lunar applications. The Mars GPR is for deeper penetration (up to 50 m depth) into the Martian subsurface at moderate resolution (0.5 m) for a geological characterization. As a part of the CRUX (Construction and Resource Utilization Explorer) instrument suite, the CRUX GPR is optimized for a lunar prospecting application. It will have shallower penetration (5 m depth) with higher resolution (10 cm) for construction operations including ISRU (in-situ resource utilization).

  15. Simulated meteoroid penetration of reusable surface insulation

    NASA Technical Reports Server (NTRS)

    Lehman, J. K.; Christensen, H. E.

    1973-01-01

    Meteoroid impact simulation test results on insulation tiles were used to determine penetration resistance of reusable surface insulation attached to simulated shuttle structures. The probability of no meteoroid damage to a typical shuttle orbiter was determined. Specimens were plasma jet tested to determine effects of various size meteoroid cavities on their thermal performance. None of the tiles failed catastrophically, but large, egg-shaped craters did result from meteoroid penetration. The metallic side of a specimen that was completely penetrated showed a petalled hole typical for thin gage shielded structures.

  16. Relations between the penetration, binding and average concentration of cytostatic drugs in human tumour spheroids.

    PubMed

    Erlanson, M; Daniel-Szolgay, E; Carlsson, J

    1992-01-01

    A penetration assay based on freeze-drying and vapour fixation was applied to show the spatial distribution of non-bound and bound cytostatic drugs in cellular spheroids. Several studies have proposed that peripheral binding of drugs correlates with limited penetration. We showed that granular accumulation, mainly at the peripheral part of spheroids, might occur in parallel with good penetration. For example, this was the case in human glioma spheroids after incubation with Adriamycin for 15-30 min. Following treatment with actinomycin D, colon carcinoma spheroids exhibited rather good penetration but also showed granular accumulation mainly in their peripheral regions. Ara-C accumulated largely and homogeneously in the peripheral regions of colon carcinoma spheroids and this severely delayed penetration. It took about 1 h for ara-C in the central regions of the spheroids to reach the same concentration as in the culture medium. In contrast, ara-C easily penetrated glioma spheroids without accumulating noticeably at the periphery. Retention tests involving washing and further incubation in drug-free culture medium revealed that the areas demonstrating extensive accumulation most often retained the drug, indicating binding, whereas the concentration of drug in other areas decreased. The oil-centrifugation method, which was used for rapid separation of the spheroids from the drug-containing medium, showed that the average concentration of daunomycin in the spheroids exceeded that in the culture medium as early as after 15 min, by which time only limited penetration had occurred. We found that good penetration of ara-C correlated with a low average concentration in glioma spheroids, whereas limited penetration correlated with a high average concentration in colon carcinoma spheroids. The latter finding was attributable to the high accumulation of drug at the spheroid periphery. Thus, there was an inverse relationship between penetration and binding and between

  17. Enumeration of petroleum-degrading microorganisms.

    PubMed Central

    Walker, J D; Colwell, R R

    1976-01-01

    A variety of factors, including concentration of oil, antibiotics, dyes, and inoculum washes, were examined to determine their effect on the total counts of microorganisms on oil-containing media. The media found to be best for enumerating petroleum-degrading microorganisms contained 0.5% (vol/vol) oil and 0.003% phenol red, with Fungizone added for isolating bacteria and streptomycin and tetracycline added for isolating yeasts and fungi. Washing the inoculum did not improve recovery of petroleum degraders. Specifically, silica gel-oil medium and a yeast medium are recommended for enumeration of petroleum-degrading bacteria and yeasts and fungi, respectively. It is suggested that counts of petroleum degraders be expressed as percentage of the total population rather than total numbers of petroleum degraders per se. Incubation temperature and presence of oil was found to influence the numbers of petroleum-degrading microorganisms at a given sampling site. PMID:999272

  18. Penetration Enzymes of Schistosome Cercariae.

    DTIC Science & Technology

    1979-12-31

    were cultured for 3, 6, 24, 48, 72, and 96 hours. Those generated in vivo remained in mouse ear tissue in situ, and those derived in vitro were kept in a... culture Ř medium of Earle’s salts containing lactalbumin hydrolysate, at 37 C in a CO 2 (5%) oven. Verification of transformation to schistosomules...mation and infectivity for mice. For ultrastructural comparison, at the end of the culture schistosomules of each derivation were fixed by two methods

  19. Laser weld penetration estimation using temperature measurements

    SciTech Connect

    Lankalapalli, K.N.; Tu, J.F.; Leong, K.H.; Gartner, M.

    1997-10-01

    Penetration depth is an important factor critical to the quality of a laser weld. This paper examines the feasibility of using temperature measurements on the bottom surface of the work-piece to estimate weld penetration. A three-dimensional analytical model relating penetration depth, weld bead width and welding speed to temperature distribution at the bottom surface of the workpiece is developed. Temperatures on the bottom surface of the workpiece are measured using infrared thermocouples located behind the laser beam. Experimental results from bead-on-plate welds on low carbon steel plates of varying thickness at different levels of laser power and speeds validate the model and show that the temperature on the bottom surface is a sensitive indicator of penetration depth. The proposed model is computationally efficient and is suitable for on-line process monitoring application.

  20. Temporary fire sealing of penetrations on TFTR

    SciTech Connect

    Hondorp, H.L.

    1981-02-01

    The radiation shielding provided for TFTR for D-D and D-T operation will be penetrated by numerous electrical and mechanical services. Eventually, these penetrations will have to be sealed to provide the required fire resistance, tritium sealability, pressure integrity and radiation attenuation. For the initial hydrogen operation, however, fire sealing of the penetrations in the walls and floor is the primary concern. This report provides a discussion of the required and desirable properties of a temporary seal which can be used to seal these penetrations for the hydrogen operation and then subsequently be removed and replaced as required for the D-D and D-T operations. Several candidate designs are discussed and evaluated and recommendations are made for specific applications.

  1. Non-normal impact of earth penetrators

    SciTech Connect

    Duffey, T.A.; Macek, R.W.

    1996-12-31

    A brief literature review of the general subject of projectile penetration into soil media is presented. Particular emphasis is placed on projectiles impacting soil targets at other than normal incidence and/or at an angle of attack, for which lateral accelerations exist and can dominate the structural response. Comparisons of predicted lateral accelerations with recent earth penetrator experiments are then made using a 3 degree-of-freedom rigid-body approach developed elsewhere to determine the external penetrator loading. Agreement between experimental and calculated accelerations is favorable, but the need to include flexible-body response is indicated. Finally a scheme to incorporate a spherical-cavity-expansion analytical procedure into a detailed finite element model of the penetrator is developed to account for flexible-body response.

  2. Shaving effects on percutaneous penetration: clinical implications.

    PubMed

    Hamza, Muhammad; Tohid, Hassaan; Maibach, Howard

    2015-01-01

    Human/animal shaving biology. To assess the effect of shaving on percutaneous penetration and skin function. We screened 500+publications in Pub Med, Scopus, Cochrane Library and pertinent journals out of which only 17 were deemed relevant. Terms for searches included shaving and skin, percutaneous penetration and shaving, skin absorption and shaving, absorption of dyes and shaving, skin penetration, effects of shaving and absorption, shave and dyes, axillary shaving and stratum corneum, shaving and breast cancer, shaving and infections, etc. Shaving appears to have an exaggerated effect on percutaneous absorption; however, some studies do not support this evidence. Shaving enhances percutaneous penetration of some chemicals; however this effect is species and chemical specific. Further investigations of chemicals of varying physio-chemical properties are mandated before a generalized theory can be promulgated.

  3. Increased in vivo skin penetration of quantum dots with UVR and in vitro quantum dot cytotoxicity

    NASA Astrophysics Data System (ADS)

    Mortensen, Luke; Zheng, Hong; Faulknor, Renea; De Benedetto, Anna; Beck, Lisa; DeLouise, Lisa A.

    2009-02-01

    The growing presence of quantum dots (QD) in a variety of biological, medical, and electronics applications means an increased risk of human exposure in manufacturing, research, and consumer use. However, very few studies have investigated the susceptibility of skin to penetration of QD - the most common exposure route- and the results of those that exist are conflicting. This suggests that a technique allowing determination of skin barrier status and prediction of skin permeability to QD would be of crucial interest as recent findings have provided evidence of in vitro cytotoxicity and long-term in vivo retention in the body for most QD surface chemistries. Our research focuses on barrier status of the skin (intact and with ultraviolet radiation induced barrier defect) and its impact on QD skin penetration. These model studies are particularly relevant to the common application condition of NP containing sunscreen and SPF cosmetics to UV exposed skin. Herein we present our initial efforts to develop an in vivo model of nanoparticle skin penetration using the SKH-1 hairless mouse with transepidermal water loss (TEWL) to evaluate skin barrier status and determine its ability to predict QD penetration. Our results show that ultraviolet radiation increases both TEWL and skin penetration of QD. Additionally, we demonstrate cytotoxic potential of QD to skin cells using a metastatic melanoma cell line. Our research suggests future work in specific targeting of nanoparticles, to prevent or enhance penetration. This knowledge will be used to develop powerful therapeutic agents, decreased penetration cosmetic nanoparticles, and precise skin cancer imaging modalities.

  4. Magnetic field penetration of erosion switch plasmas

    NASA Astrophysics Data System (ADS)

    Mason, Rodney J.; Jones, Michael E.; Grossmann, John M.; Ottinger, Paul F.

    1988-10-01

    Computer simulations demonstrate that the entrainment (or advection) of magnetic field with the flow of cathode-emitted electrons can constitute a dominant mechanism for the magnetic field penetration of erosion switch plasmas. Cross-field drift in the accelerating electric field near the cathode starts the penetration process. Plasma erosion propagates the point for emission and magnetic field injection along the cathode toward the load-for the possibility of rapid switch opening.

  5. Low Force Penetration of Icy Regolith

    NASA Technical Reports Server (NTRS)

    Mantovani, J. G.; Galloway, G. M.; Zacny, K.

    2016-01-01

    A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

  6. Anomalous toroidal field penetration in Tormac V

    SciTech Connect

    Feinberg, B.; Vaucher, B. G.; Shaw, R. S.; Vella, M. C.

    1981-07-01

    We investigate magnetic field penetration into a cool, collisional, magnetized plasma in Tormac V. Magnetic probe and laser interferometer studies reveal anomalous penetration of the applied toroidal field into a plasma with an initial parallel bias toroidal field. The applied poloidal field, however, formed a well-defined magnetic front which was effective at sweeping up particles. Lastly, strong shear in the vacuum magnetic field does not inhibit the apparent decoupling of the applied toroidal field from the applied poloidal field.

  7. Dentinal Tubule Penetration of Tricalcium Silicate Sealers.

    PubMed

    McMichael, Greer E; Primus, Carolyn M; Opperman, Lynne A

    2016-04-01

    The treatments for which mineral trioxide aggregate (MTA)-based materials can be used in dentistry are expanding. Smaller particle size and easier handling properties have allowed the advent of tricalcium silicate sealers including EndoSequence BC Sealer (Brasseler USA, Savannah, GA), QuickSet2 (Avalon Biomed, Bradenton, FL), NeoMTA Plus (Avalon Biomed), and MTA Fillapex (Angelus, Londrina, Brazil). The objective of this study was to measure the tubule penetration with these sealers using continuous wave (CW) and single-cone (SC) obturation techniques. Eighty single-rooted teeth were randomly divided into 8 groups of 10 and obturated with 1 of the previously mentioned sealers mixed with trace amounts of rhodamine using either the CW or SC technique. Teeth were sectioned at 1 mm and 5 mm from the apex and examined under a confocal laser microscope. The percentage of sealer penetration and the maximum sealer penetration were measured. The tricalcium silicate sealers penetrated tubules as deep as 2000 μm (2 mm). The percentage of sealer penetration was much higher 5 mm from the apex, with many specimens having 100% penetration for both SC and warm vertical techniques. MTA Fillapex, a resin-based sealer with less than 20% MTA particles, had significantly greater tubule penetration with a warm vertical technique versus the SC technique at the 1-mm level. Within the limitations of this study, the CW and SC techniques produced similar tubule penetration at both the 1-mm and the 5-mm level with the tricalcium silicate sealers BC Sealer, QuickSet2, and NeoMTA Plus. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. An in vitro skin penetration model for compromised skin: estimating penetration of polyethylene glycol [¹⁴C]-PEG-7 phosphate.

    PubMed

    Dey, Swatee; Rothe, Helga; Page, Leanne; O'Connor, Robert; Farahmand, Sara; Toner, Frank; Marsh, Randy; Wehmeyer, Ken; Zhou, Shaoying

    2015-01-01

    Establishing dermal penetration rates is important to better understand the safety of topically applied materials, especially for premature infant skin with compromised skin barrier function. Skin prematurity involves thinner stratum corneum and underdeveloped epidermis/dermis resulting in decreased barrier function, higher transepidermal water loss and greater chemical penetration, when compared to healthy full-term neonate/adult skin. We developed an in vitro skin penetration model using human ex vivo skin to estimate penetration for premature/compromised skin barrier conditions by tape stripping. Skin barrier deficiency was characterized by transepidermal water loss. Baby wipe lotion containing 5 mg/cm(2) [(14)C]-PEG-7 phosphate was applied 5 times to human skin samples of intact, moderately or highly compromised skin barrier and once at 25 mg/cm(2) over 24 h. Overall penetration of [(14)C]-PEG-7 phosphate was low (<5%) even for highly compromised skin. The absorption rate was higher (p < 0.001) for compromised skin versus intact skin. No significant difference was seen between moderately and highly compromised skin by repeated dosing. Under single-dose conditions, penetration through highly compromised skin was significantly higher compared to intact skin (p = 0.001). Our model demonstrates that even under highly compromised skin conditions, penetration of [(14)C]-PEG-7 phosphate is low (<5%) and only 4-6 times higher compared to mature/intact skin and does not approach 100%. Penetration was unaffected by single or multiple dosing conditions. © 2014 S. Karger AG, Basel.

  9. CNS Active O-Linked Glycopeptides that Penetrate the BBB

    NASA Astrophysics Data System (ADS)

    Jones, Evan; Polt, Robin

    2015-06-01

    Naturally occurring glycopeptides and glycoproteins play important roles in biological processes. Glycosylation is one of the most common post-translational modifications in vivo. Glycopeptides are involved in cell signaling and sorting, providing cell surface markers for recognition. From the drug design and synthesis perspective, modification of a peptide through glycosylation results in increased bioavailability and bioactivity of glycopeptides in living systems with negligible toxicity of degradation products. Glycopeptide synthesis can be accomplished through incorporation of a glycosylated amino acid in solid phase peptide synthesis (SPPS) to form the desired peptide, or via incorporation of sugar-amino acid moieties. Additionally, research indicates that glycosylation increases penetration of the blood-brain barrier (BBB) by peptides, which may lead to novel therapeutics for neurological disorders. Recent applications of glycopeptides have focused on the in vivo central nervous system effects after peripheral administration of centrally active peptides modified with various carbohydrates.

  10. Rational design of a biomimetic cell penetrating peptide library.

    PubMed

    Karagiannis, Emmanouil D; Urbanska, Aleksandra M; Sahay, Gaurav; Pelet, Jeisa M; Jhunjhunwala, Siddharth; Langer, Robert; Anderson, Daniel G

    2013-10-22

    Cell penetrating peptides have demonstrated potential to facilitate the cellular delivery of therapeutic molecules. Here we develop a set of 50 cell penetrating peptide based formulations with potential to deliver small interfering RNAs intercellularly. The transfection efficacy of siRNA containing lipid-like nanoparticles decorated with different peptides was evaluated both in vitro and in vivo and correlated with the peptide physical and chemical properties. In vitro, these particles were internalized primarily through macropinocytosis. When the peptides were presented to bone marrow-derived dendritic cells, they induce low immunoactivation relative to control cell penetrating peptides including the antennapedia homeodomain and TAT, as quantified by the expression of activation specific surface proteins like CD80, CD86, and major histocompatibility complex class II. In vivo, peptide decorated nanoparticles primarily accumulated in the lungs and the liver. Three human peptides derived from surfactant protein B (a lung surfactant protein), orexin (a neuropeptide hormone, and lactoferricin (a globular glycoprotein) that exist in many physiological fluids facilitated the in vivo delivery of siRNA and induce significant knock down (90%) of a hepatocyte expressed protein, coagulation Factor VII.

  11. Catastrophic failure of stored energy modules following orbital debris penetration

    NASA Astrophysics Data System (ADS)

    Williamsen, Joel E.; Goodwin, Charles J.

    1996-10-01

    The population of dangerous orbital debris particles in low Earth orbit is growing, resulting in a need for improved risk assessment and risk management of critical space station elements from this hypervelocity impact threat. The effects of micrometeoroid and orbital debris (M/OD) penetration on space station equipment can very from a local damage problem to a possible catastrophic system failure (i.e., crew or station loss). Given this possibility, a preliminary study was undertaken by Meyer Analytics and NASA-MSFC to quantify and reduce the likelihood of catastrophic failure following orbital debris penetration of two Russian supplied modules: the FGB Energy Block module and the SPP-1 gyrodyne module. Each of these modules contains stored energy in the form of chemical propellants (UDMH), high pressure tanks, or kinetic energy (gyrodynes) that may release energy and propagate damage to the rest of the space station if impacted by a sufficiently energetic orbital debris particle. The study recommended design improvements to lower these probabilities, including spall blankets around the gyrodynes to lower the probability of gyrodyne penetration and fragment damage given gyrodyne rupture.

  12. Dosimeter for measuring skin dose and more deeply penetrating radiation

    DOEpatents

    Jones, Donald E.; Parker, DeRay; Boren, Paul R.

    1981-01-01

    A personnel dosimeter includes a plurality of compartments containing thermoluminescent dosimeter phosphors for registering radiation dose absorbed in the wearer's sensitive skin layer and for registering more deeply penetrating radiation. Two of the phosphor compartments communicate with thin windows of different thicknesses to obtain a ratio of shallowly penetrating radiation, e.g. beta. A third phosphor is disposed within a compartment communicating with a window of substantially greater thickness than the windows of the first two compartments for estimating the more deeply penetrating radiation dose. By selecting certain phosphors that are insensitive to neutrons and by loading the holder material with netruon-absorbing elements, energetic neutron dose can be estimated separately from other radiation dose. This invention also involves a method of injection molding of dosimeter holders with thin windows of consistent thickness at the corresponding compartments of different holders. This is achieved through use of a die insert having the thin window of precision thickness in place prior to the injection molding step.

  13. Romanomermis culicivorax: penetration of larval mosquitoes.

    PubMed

    Shamseldean, M M; Platzer, E G

    1989-09-01

    In the presence of second larval instars of three mosquito species the preparasites of Romanomermis culicivorax swam near the water surface in an orthokinetic manner. When the preparasites were ca. 1 mm from the host, they stopped and swam klinotactically toward the host. During this phase, the preparasites secreted a small amount of a putative adhesive material from the anterior region and host contact was completed. The adhesive appeared to aid in attachment of the preparasites to the host and initiation of the search-boring phase. The preparasites glided over the host until a suitable penetration site was found. The penetration phase was initiated by probing with the odontostyle. This was followed by partial paralysis, decreased intestinal peristaltic movement, and temporary cardiac arrest in all host mosquitoes which was probably related to injection of esophageal secretions. SEM observations showed that the abdominal walls were the most frequent site for penetration. As the preparasites entered through the penetration hole, microorganisms adhering to the cuticle of the preparasites were retained by the adhesive which accumulated around the penetration site. Thus, microbial contamination of the host was avoided by a mechanical cleansing mechanism. Penetration was usually completed in less than 10 min.

  14. Estimating Consequences of MMOD Penetrations on ISS

    NASA Technical Reports Server (NTRS)

    Evans, H.; Hyde, James; Christiansen, E.; Lear, D.

    2017-01-01

    The threat from micrometeoroid and orbital debris (MMOD) impacts on space vehicles is often quantified in terms of the probability of no penetration (PNP). However, for large spacecraft, especially those with multiple compartments, a penetration may have a number of possible outcomes. The extent of the damage (diameter of hole, crack length or penetration depth), the location of the damage relative to critical equipment or crew, crew response, and even the time of day of the penetration are among the many factors that can affect the outcome. For the International Space Station (ISS), a Monte-Carlo style software code called Manned Spacecraft Crew Survivability (MSCSurv) is used to predict the probability of several outcomes of an MMOD penetration-broadly classified as loss of crew (LOC), crew evacuation (Evac), loss of escape vehicle (LEV), and nominal end of mission (NEOM). By generating large numbers of MMOD impacts (typically in the billions) and tracking the consequences, MSCSurv allows for the inclusion of a large number of parameters and models as well as enabling the consideration of uncertainties in the models and parameters. MSCSurv builds upon the results from NASA's Bumper software (which provides the probability of penetration and critical input data to MSCSurv) to allow analysts to estimate the probability of LOC, Evac, LEV, and NEOM. This paper briefly describes the overall methodology used by NASA to quantify LOC, Evac, LEV, and NEOM with particular emphasis on describing in broad terms how MSCSurv works and its capabilities and most significant models.

  15. Penetration of erythromycin through Staphylococcus epidermidis biofilm.

    PubMed

    Lin, Mao-hu; He, Lei; Gao, Jie; Liu, Yun-xi; Suo, Ji-jiang; Xing, Yu-bin; Jia, Ning

    2013-07-01

    The catheter related infection caused by Staphylococcus epidermidis biofilm is increasing and difficult to treat by antimicrobial chemotherapy. The properties of biofilms that give rise to antibiotic resistance are only partially understood. This study aimed to elucidate the penetration of erythromycin through Staphylococcus epidermidis biofilm. The penetration ratio of erythromycin through Staphylococcus epidermidis biofilms of 1457, 1457-msrA, and wild isolate S68 was detected by biofilm penetration model at different time points according to the standard regression curve. The RNA/DNA ratio and the cell density within the biofilms were observed by confocal laser microscope and transmission electromicroscope, respectively. The penetration ratios of erythromycin through the biofilms of 1457, 1457-msrA, and S68 after cultivation for 36 hours were 0.93, 0.55 and 0.4, respectively. The erythromycin penetration ratio through 1457 biofilm (0.58 after 8 hours) was higher than that through the other two (0.499 and 0.31 after 24 hours). Lower growth rate of the cells in biofilm was shown, with reduction of RNA/DNA proportion observed by confocal laser microscope through acridine orange stain. Compared with the control group observed by transmission electrmicroscope, the cell density of biofilm air face was lower than that of agar face, with more cell debris. Erythromycin could penetrate to the Staphylococcus epidermidis biofilm, but could not kill the cells thoroughly. The lower growth rate of the cells within biofilm could help decreasing the erythromycin susceptibility.

  16. Hermetic optical fiber penetrators for aquatic environments

    NASA Astrophysics Data System (ADS)

    Burke, Gregory C.

    1992-12-01

    The primary purpose of fiber optic penetrators is to provide a safe and reliable optical path through a hermetic barrier. The penetrators must resist pressure, humidity, corrosion, and maintain optical and mechanical integrity. Many optical fiber penetrators are manufactured from a combination of epoxies and application of a physical pressure seal onto the fiber. While providing a short term solution, epoxy lacks long term hermetic protection. Physical force applied to the fiber from a pressure seal may affect the refractive index of the optical cladding in soft and hard clad silica fibers. This presentation describes methods to provide a positive hermetic seal to a variety of optical fibers. These penetrators do not use lenses, prisms, or other conventional optical relay systems. Penetrators are intrinsically radiation hard and offer the convenience of providing a standard connector interface on one or both sides of the device. Examples of aquatic and high vacuum penetrators are presented. Application for this technology spans fiber geometry from single mode to large core step index fibers. Uses include communications and high energy transmission. This technology also is applicable to fiber based sensors.

  17. Ground penetrating radar field evaluation in Angola

    NASA Astrophysics Data System (ADS)

    Walls, Richard; Brown, Todd; Clodfelter, Fred; Coors, Jeff; Laudato, Stephen; Lauziere, Steve; Patrikar, Ajay; Poole, Michael; Price, Mike

    2006-05-01

    Deminers around the globe are still using handheld metal detectors that lack the capability to distinguish mines from clutter, detect mines containing very little metal, or find mines buried at deeper depths. In the southern African country of Angola, many areas and roads are impassable due to the threat of anti-tank landmines. Some of these mines are undetectable using current metal detector technology. The US Army has funded the development of the NIITEK ground penetrating radar (GPR) for detection of anti-tank (AT) landmines. This radar detects metal and plastic mines as well as mines that are buried too deep for handheld metal detectors to find. The US Department of Defense Humanitarian Demining (HD) Research & Development Program focuses on developing, testing, demonstrating, and validating new technology for immediate use in humanitarian demining operations around the globe. The HD team provided funding and guidance to NIITEK Incorporated for development of a prototype system called Mine Stalker - a relatively light-weight, remote-controlled vehicle outfitted with the NIITEK GPR, detection algorithms, and a marking system. Individuals from the HD team, NIITEK Inc, and the non-governmental organization Meschen Gegen Minen (MgM) participated in a field evaluation of the Mine Stalker in Angola. The primary aim was to evaluate the effectiveness and reliability of the NIITEK GPR under field conditions. The Mine Stalker was extremely reliable during the evaluation with no significant maintenance issues. All AT mines used to verify GPR performance were detected, even when buried to depths as deep as 25-33cm.

  18. MECHANISM OF CELL WALL PENETRATION BY VIRUSES

    PubMed Central

    Puck, Theodore T.; Lee, Howard H.

    1954-01-01

    Treatment of radioactively labelled host cells with T1 or T2 bacteriophages induces a leakage of cellular P and S into the medium. Evidence is presented showing that this increased cell permeability is not the result of complete lysis of a small fraction of the cells, but rather is made up of contributions from all or most of the infected population. This leakage of cellular constituents exhibits the following characteristics: (a) Infection of a cell with a single virus suffices to evoke the reaction; (b) Increasing the multiplicity up to 7 to 8 virus particles per cell does not affect the extent of leakage produced; (c) Some leakage does occur at 0°C., but much less than at 37°C.; (d) Infection by T1 virus results in a smaller amount of leakage than in the case of T2, but the pattern of response to varying virus multiplicity is the same; (e) The P resulting from such leakage contains no DNA and chemically resembles that which elutes in smaller amounts from uninfected cells; (f) At 37°C. the virus-induced leakage reaction appears within a matter of seconds, and usually decreases after 2 to 3 minutes; (g) The reaction is inhibited by 0.025 M Mg++. Theoretical considerations are presented suggesting the place of this reaction in the sequence of events constituting the virus penetration reaction; its relationship to the phenomenon of lysis-from-without; and its resemblance to the leakage reaction produced by electrostatic binding of ionized compounds to cell surfaces. The existence of similar effects in avian-mammalian virus systems is noted. PMID:13163323

  19. Hybrid Collagenase Nanocapsules for Enhanced Nanocarrier Penetration in Tumoral Tissues.

    PubMed

    Villegas, María Rocío; Baeza, Alejandro; Vallet-Regí, María

    2015-11-04

    Poor penetration of drug delivery nanocarriers within dense extracellular matrices constitutes one of the main liabilities of current nanomedicines. The conjugation of proteolytic enzymes on the nanoparticle surface constitutes an attractive alternative. However, the scarce resistance of these enzymes against the action of proteases or other aggressive agents present in the bloodstream strongly limits their application. Herein, a novel nanodevice able to transport proteolytic enzymes coated with an engineered pH-responsive polymeric is presented. This degradable coat protects the housed enzymes against proteolytic attack at the same time that it triggers their release under mild acidic conditions, usually present in many tumoral tissues. These enzyme nanocapsules have been attached on the surface of mesoporous silica nanoparticles, as nanocarrier model, showing a significatively higher penetration of the nanoparticles within 3D collagen matrices which housed human osteosarcoma cells (HOS). This strategy can improve the therapeutic efficacy of the current nanomedicines, allowing a more homogeneous and deeper distribution of the therapeutic nanosystems in cancerous tissues.

  20. Are cognitive outcome and recovery different in civilian penetrating versus non-penetrating brain injuries?

    PubMed

    Ylioja, Shelley; Hanks, Robin; Baird, Anne; Millis, Scott

    2010-10-01

    The present study sought to determine whether cognitive outcome and course of recovery in civilian penetrating brain injury due to gunshot can be distinguished from that of non-penetrating brain injury due to motor vehicle accident. Matched survivors of penetrating and non-penetrating brain injury were assessed with a brief neuropsychological test battery at inpatient rehabilitation, 1 year post-injury, and 2 years post-injury. The traumatic brain injury groups were found to have patterns of performance marked by reliably distinct differences in isolated areas, with different cognitive predictors of brain injury type present in early versus later recovery. The degree of recovery over the first 2 years appeared to be quite similar for penetrating and non-penetrating injuries.

  1. The Current Status of the Japanese Penetrator Mission: LUNAR-A

    NASA Astrophysics Data System (ADS)

    Tanaka, S.; Shiraishi, H.; Fujimura, A.; Hayakawa, H.

    The scientific objective of the LUNAR-A, Japanese Penetrator Mission, is to explore the lunar interior by seismic and heat-flow experiments. Two penetrators containing two seismometers (horizontal and vertical components) and heat-flow probes will be deployed from a spacecraft onto the lunar surface, one on the nearside and the other on the farside of the moon. The final impact velocity of the penetrator will be about 300m/sec; it will encounter a shock of about 8000 G at impact on the lunar surface. According to numerous experimental impact tests using model penetrators and a lunar regolith analog target, each penetrator is predicted to penetrate to a depth of 1 to 3 m. The data obtained by the penetrators will be transmitted to the earth station via the LUNAR-A mother spacecraft orbiting at an altitude of about 200 km. The penetrator is a missile-shaped instrument carrier, which is about 14cm in diameter, 75cm in length, and about 14kg in weight without attitude control system. It contains a two-component seismometer and heat flow probes together with other supporting instruments such as a tilt meter and an accelerometer. The seismic observations are expected to provide key data on the size of the lunar core, as well as data on deep lunar mantle structure. The heat flow measurements at two penetrator deployment sites will also provide important data on the thermal structure and bulk concentrations of heat-generating elements in the Moon. These data will provide much stronger geophysical constraints on the origin and evolution of the Moon than has been obtained so far. The LUNAR-A spacecraft was supposed to be launched in the summer of 2004, but it was postponed due to the necessity of a replacement of the valves used in the RCS propulsion system of the spacecraft, following a recall issued by the manufacturer who found a malfunction of similar valves. Then, the technological review boards by ISAS and JAXA recommended that both the more robustness of the

  2. Trans-resveratrol and beta-carotene from sunscreens penetrate viable skin layers and reduce cutaneous penetration of UV-filters.

    PubMed

    Freitas, J V; Praça, F S G; Bentley, M V L B; Gaspar, L R

    2015-04-30

    Cutaneous permeation is a critical parameter when topical application of sunscreens containing antioxidants is considered. The aim of this study was to evaluate the cutaneous penetration of most marketed UV-filters combined with trans-resveratrol (RES) and beta-carotene (BTC) since few studies report skin penetration when such compounds are applied. Formulations containing octocrylene, octyl methoxycinnamate, avobenzone and bemotrizinole were prepared and supplemented or not with BTC, or with RES, or with both compounds in combination. Penetration studies were performed using Franz vertical diffusion cells and porcine ear skin as the biological membrane. The quantification of UV-filters and antioxidants in the stratum corneum (SC), viable epidermis plus dermis and receptor fluid was performed by HPLC. Results suggested that UV-filters and antioxidants did not permeate the skin but were retained for 12h post application. About 90% and 80%, respectively, of the total penetrated amount of UV-filters and antioxidants was found in the SC. Interestingly, it was observed that BTC, alone or combined with RES, reduced the skin retention of UV-filters on average by 63%. In conclusion, this study demonstrated that the combination of antioxidants and UV-filters in sunscreens is advantageous for cutaneous penetration, since BTC and BTC+RES improved sunscreen safety by reducing delivery of the four UV-filters in the study into SC and viable epidermis. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Computational model for armor penetration. Annual report No. 2, October 1979-October 1980

    SciTech Connect

    Erlich, D.C.; Seaman, L.; Curran, D.R.; Shockey, D.A.; Caligiuri, R.D.

    1987-10-01

    Results are reported from the second year of a three-year BRL/AMMRC/SRI program to develop a computational capability for predicting the behind-the-armor fragment environment for spaced armor attacked by long-rod penetrators. The baseline materials chosen were rolled homogenous steel armor (RHA) and depleted uranium (DU) for the penetrator. Phenomenological studies involving both quarter and full-scale ballistics tests at velocities up to 1.5 km/s and obliquities from 0 to 70 clearly revealed shear banding to be the principal phenomenon controlling both penetrator erosion and armor failure. A detailed, phenomenological scenario for oblique armor penetration is given . Contained fragmenting cylinder (CFC) experiments were performed to characterize the resistance of RHA to shear banding; a significant anisotropy was observed. The SHEAR3 computational model for shear banding was refined and calibrated with respect to previously obtained data from CFC experiments using 4340 steel (Rc40).

  4. The ``Pen`` penetration analysis code: Comparison with experiments and with CALE calculations

    SciTech Connect

    Simonson, S.C. III

    1993-04-01

    The ``Pen`` computer program has been developed for the analysis of penetration by shaped charge jets. In addition to standard methods for calculating the depth of penetration and the radius of the hole produced by a stretching jet, Pen contains new methods for treating the onset of particulation and for calculating the depth of penetration by a particulated jet. A Pen analysis was compared with a detailed calculation carried out with the LLNL Arbitrary Lagrangian-Eulerian code CALE. Pen was also applied to the analysis of two shaped charge jet penetration experiments. Pen reproduced the CALE hole profile and the experimental profiles when the effective strength in the steel targets was set to 1.2--1.3 times the yield strength. An experimental value of 1.44 {plus_minus} 0.19 GPa was obtained for the effective strength of hardened A4340 steel under jet impact.

  5. Confocal Raman microscopic investigation of the effectiveness of penetration enhancers for procaine delivery to the skin

    NASA Astrophysics Data System (ADS)

    Lunter, Dominique; Daniels, Rolf

    2014-12-01

    A methodology that employs confocal Raman microscopy (CRM) on ex vivo skin samples is proposed for the investigation of drug content and distribution in the skin. To this end, the influence of the penetration enhancers propylene glycol and polyoxyethylene-23-lauryl ether on the penetration and permeation of procaine as a model substance was investigated. The drug content of skin samples that had been incubated with semisolid formulations containing one of these enhancers was examined after skin segmentation. The experiments showed that propylene glycol did not affect the procaine content that was delivered to the skin, whereas polyoxyethylene-23-lauryl ether led to higher procaine contents and deeper penetration. Neither substance was found to influence the permeation rate of procaine. It is thereby shown that CRM can provide additional information on drug penetration and permeation. Furthermore, the method was found to enhance the depth from which Raman spectra can be collected and to improve the depth resolution compared to previously proposed methods.

  6. Analytical Improvements in PV Degradation Rate Determination

    SciTech Connect

    Jordan, D. C.; Kurtz, S. R.

    2011-02-01

    As photovoltaic (PV) penetration of the power grid increases, it becomes vital to know how decreased power output may affect cost over time. In order to predict power delivery, the decline or degradation rates must be determined accurately. For non-spectrally corrected data several complete seasonal cycles (typically 3-5 years) are required to obtain reasonably accurate degradation rates. In a rapidly evolving industry such a time span is often unacceptable and the need exists to determine degradation rates accurately in a shorter period of time. Occurrence of outliers and data shifts are two examples of analytical problems leading to greater uncertainty and therefore to longer observation times. In this paper we compare three methodologies of data analysis for robustness in the presence of outliers, data shifts and shorter measurement time periods.

  7. Verification of Sulfate Attack Penetration Rates for Saltstone Disposal Unit Modeling

    SciTech Connect

    Flach, G. P.

    2015-05-12

    Recent Special Analysis modeling of Saltstone Disposal Units consider sulfate attack on concrete and utilize degradation rates estimated from Cementitious Barriers Partnership software simulations. This study provides an independent verification of those simulation results using an alternative analysis method and an independent characterization data source. The sulfate penetration depths estimated herein are similar to the best-estimate values in SRNL-STI-2013-00118 Rev. 2 and well below the nominal values subsequently used to define Saltstone Special Analysis base cases.

  8. Degrading and non-degrading sex in popular music: a content analysis.

    PubMed

    Primack, Brian A; Gold, Melanie A; Schwarz, Eleanor B; Dalton, Madeline A

    2008-01-01

    Those exposed to more degrading sexual references in popular music are more likely to initiate intercourse at a younger age. The purpose of this study was to perform a content analysis of contemporary popular music with particular attention paid to the prevalence of degrading and non-degrading sexual references. We also aimed to determine if sexual references of each subtype were associated with other song characteristics and/or content. We used Billboard magazine to identify the top popular songs in 2005. Two independent coders each analyzed all of these songs (n = 279) for degrading and non-degrading sexual references. As measured with Cohen's kappa scores, inter-rater agreement on degrading vs. non-degrading sex was substantial. Mentions of substance use, violence, and weapon carrying were also coded. Of the 279 songs identified, 103 (36.9%) contained references to sexual activity. Songs with references to degrading sex were more common than songs with references to non-degrading sex (67 [65.0%] vs. 36 [35.0%], p < 0.001). Songs with degrading sex were most commonly Rap (64.2%), whereas songs with non-degrading sex were most likely Country (44.5%) or Rhythm & Blues/Hip-Hop (27.8%). Compared with songs that had no mention of sexual activity, songs with degrading sex were more likely to contain references to substance use, violence, and weapon carrying. Songs with non-degrading sex were no more likely to mention these other risk behaviors. References to sexual activity are common in popular music, and degrading sexual references are more prevalent than non-degrading references. References to degrading sex also frequently appear with references to other risky behaviors.

  9. Hemocompatible poly(NIPAm-MBA-AMPS) colloidal nanoparticles as carriers of anti-inflammatory cell penetrating peptides.

    PubMed

    Bartlett, Rush L; Medow, Matthew R; Panitch, Alyssa; Seal, Brandon

    2012-04-09

    Anionic copolymer systems containing sulfated monomers have great potential for delivery of cationic therapeutics, but N-isopropylacrylamide (NIPAm) 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) copolymer nanoparticles have seen limited characterization to date with regard to physical properties relevant to loading and release of therapeutics. Characterization of polymeric nanoparticles incorporating AMPS showed an increased size and decreased thermodynamic swelling ratios of AMPS containing particles as compared to NIPAm nanoparticles lacking AMPS. Particles with increasing AMPS addition showed an increased propensity for uniformity, intraparticle colloidal stability, and drug loading capacity. Peptide encapsulated in particles was shielded from peptide degradation in serum. Particles were shown not impede blood coagulation or to cause hemolysis. This study has demonstrated that AMPS incorporation into traditional NIPAm nanoparticles presents a tunable parameter for changing particle LCST, size, swelling ratio, ζ potential, and cationic peptide loading potential. This one-pot synthesis results in a thermosensitive anionic nanoparticle system that is a potentially useful platform to deliver cationic cell penetrating peptides.

  10. Cellobiose dehydrogenase in cellulose degradation

    SciTech Connect

    Eriksson, L.; Igarashi, Kiyohiko; Samejima, Masahiro

    1996-10-01

    Cellobiose dehydrogenase is produced by a variety of fungi. Although it was already discovered during the 70`s, it`s role in cellulose and lignin degradation is yet ambiguous. The enzyme contains both heme and FAD as prosthetic groups, and seems to have a domain specifically designed to bind the enzyme to cellulose. It`s affinity to amorphous cellulose is higher than to crystalline cellulose. We will report on the binding behavior of the enzyme, its usefulness in elucidation of cellulose structures and also, possibilities for applications such as its use in measuring individual and synergistic mechanisms for cellulose degradation by endo- and exo-glucanases.

  11. DNA Degradation and Its Defects

    PubMed Central

    Kawane, Kohki; Motani, Kou; Nagata, Shigekazu

    2014-01-01

    DNA is one of the most essential molecules in organisms, containing all the information necessary for organisms to live. It replicates and provides a mechanism for heredity and evolution. Various events cause the degradation of DNA into nucleotides. DNA also has a darker side that has only recently been recognized; DNA that is not properly degraded causes various diseases. In this review, we discuss four deoxyribonucleases that function in the nucleus, cytosol, and lysosomes, and how undigested DNA causes such diseases as cancer, cataract, and autoinflammation. Studies on the biochemical and physiological functions of deoxyribonucleases should continue to increase our understanding of cellular functions and human diseases. PMID:24890510

  12. Diversity-Oriented Stapling Yields Intrinsically Cell-Penetrant Inducers of Autophagy

    PubMed Central

    2017-01-01

    Autophagy is an essential pathway by which cellular and foreign material are degraded and recycled in eukaryotic cells. Induction of autophagy is a promising approach for treating diverse human diseases, including neurodegenerative disorders and infectious diseases. Here, we report the use of a diversity-oriented stapling approach to produce autophagy-inducing peptides that are intrinsically cell-penetrant. These peptides induce autophagy at micromolar concentrations in vitro, have aggregate-clearing activity in a cellular model of Huntington’s disease, and induce autophagy in vivo. Unexpectedly, the solution structure of the most potent stapled peptide, DD5-o, revealed an α-helical conformation in methanol, stabilized by an unusual (i,i+3) staple which cross-links two d-amino acids. We also developed a novel assay for cell penetration that reports exclusively on cytosolic access and used it to quantitatively compare the cell penetration of DD5-o and other autophagy-inducing peptides. These new, cell-penetrant autophagy inducers and their molecular details are critical advances in the effort to understand and control autophagy. More broadly, diversity-oriented stapling may provide a promising alternative to polycationic sequences as a means for rendering peptides more cell-penetrant. PMID:28414223

  13. Dopant penetration studies through Hf silicate

    NASA Astrophysics Data System (ADS)

    Quevedo-Lopez, M. A.; Visokay, M. R.; Chambers, J. J.; Bevan, M. J.; LiFatou, A.; Colombo, L.; Kim, M. J.; Gnade, B. E.; Wallace, R. M.

    2005-02-01

    We present a study of the penetration of B, P, and As through Hf silicate (HfSixOy) and the effect of N incorporation in Hf silicate (HfSixOyNz) on dopant penetration from doped polycrystalline silicon capping layers. The extent of penetration through Hf silicate was found to be dependent upon the thermal annealing budget for each dopant investigated as follows: B(T⩾950°C/60s), P(T⩾1000°C/20s), and As (T⩾1050°C/60s). We propose that the enhanced diffusion observed for these dopants in HfSixOy, compared with that of SiO2 films, is related to grain boundary formation resulting from HfSixOy film crystallization. We also find that, as in the case of SiO2, N incorporation inhibits dopant (B, P, and As) diffusion through the Hf silicate and thus penetration into the underlying Si substrate. Only B penetration is clearly observed through HfSiON films for anneals at 1050 °C for durations of 10 s or longer. The calculated B diffusivity through the HfSixOyNz layer is D0=5.2×10-15cm2/s.

  14. Penetrators (penetrating sondes) and new possibilities for study of the planets

    NASA Technical Reports Server (NTRS)

    Davydov, V. D.; Skuridin, G. A.

    1979-01-01

    The fields of possible use of penetrators in space research are considered. A survey of the condition of development and plans for use of penetrators abroad is presented and an analysis is given of the significance of scientific problems when probing planets.

  15. Sunshot Initiative High Penetration Solar Portal

    DOE Data Explorer

    The DOE SunShot Initiative is a collaborative national initiative to make solar energy cost-competitive with other forms of energy by the end of the decade. Reducing the installed cost of solar energy systems by about 75% will drive widespread large-scale adoption of this renewable energy and restore U.S. leadership in the global clean energy race. The High Penetration Solar Portal was created as a resource to aggregate the most relevant and timely information related to high penetration solar scenarios and integrating solar into the grid. The site is designed so that utilities, grant awardees, regulators, researchers, and other solar professionals can easily share data, case studies, lessons learned, and demonstration project findings. [from https://solarhighpen.energy.gov/about_the_high_penetration_solar_portal

  16. METHOD AND APPARATUS FOR EARTH PENETRATION

    DOEpatents

    Adams, W.M.

    1963-12-24

    A nuclear reactor apparatus for penetrating into the earth's crust is described. The apparatus comprises a cylindrical nuclear core operating at a temperature that is higher than the melting temperature of rock. A high-density ballast member is coupled to the nuclear core such that the overall density of the core-ballast assembly is greater than the density of molten rock. The nuclear core is thermally insulated so that its heat output is constrained to flow axially, with radial heat flow being minimized. In operation, the apparatus is placed in contact with the earth's crust at the point desired to be penetrated. The heat output of the reactor melts the underlying rock, and the apparatus sinks through the resulting magma. The fuel loading of the reactor core determines the ultimate depth of crust penetration. (AEC)

  17. Penetrating power of resonant electromagnetic induction imaging

    NASA Astrophysics Data System (ADS)

    Guilizzoni, Roberta; Watson, Joseph C.; Bartlett, Paul; Renzoni, Ferruccio

    2016-09-01

    The possibility of revealing the presence and identifying the nature of conductive targets is of central interest in many fields, including security, medicine, industry, archaeology and geophysics. In many applications, these targets are shielded by external materials and thus cannot be directly accessed. Hence, interrogation techniques are required that allow penetration through the shielding materials, in order for the target to be identified. Electromagnetic interrogation techniques represent a powerful solution to this challenge, as they enable penetration through conductive shields. In this work, we demonstrate the power of resonant electromagnetic induction imaging to penetrate through metallic shields (1.5-mm-thick) and image targets (having conductivities σ ranging from 0.54 to 59.77 MSm-1) concealed behind them.

  18. Approach for estimating soil attachment during penetration events

    SciTech Connect

    McNeill, R.L.

    1981-08-01

    It is not presently known if significant soil attachment occurs during a penetration event. If attachment occurs, the penetrator may thereby experience increased decelerating forces and the design loads on the penetrator body may be different from the nonattached case. A method is developed to identify when attachment may occur and to estimate the resulting loads on the penetrator. The important parameters are the weight and dimensions of the penetrator, the velocity of the penetrator, and the stiffness of the soil. The method is intended to guide the design of definitive experiments to identify if attachment occurs and to assess the significance of attachment to the design of penetrators.

  19. Containment of composite fan blades

    NASA Technical Reports Server (NTRS)

    Coppa, A. P.; Stotler, C. L.

    1977-01-01

    The development of containment concepts for use with large composite fan blades, taking into account the frangible nature of composite blades is considered. Aspects of the development program include; (1) an analysis to predict the interaction between a failed fan blade and the blade containment structure; (2) scaling factors to allow impact testing using subscale containment rings and simulated blades; (3) the design and fabrication of containment systems for further evaluation in a rotating rig test facility; (4) evaluate the test data against the analytically predicted results; and (5) determine overall systems weights and design characteristics of a composite fan stage installation and compare to the requirements of an equivalent titanium fan blade system. Progress in the blade impact penetration tests and the design and fabrication of blade containment systems is reported.

  20. The effect of welding parameters on penetration in GTA welds

    SciTech Connect

    Shirali, A.A. ); Mills, K.C. )

    1993-07-01

    The effect of various welding parameters on the penetration of GTA welds has been investigated. Increases in welding speed were found to reduce penetration; however, increases in welding current were observed to increase the penetration in high sulfur (HS) casts and decrease penetration in low sulfur (LS) steels. Plots of penetration as a function of increasing linear energy (the heat supplied per unit length of weld) revealed a similar trend with increased penetration in HS casts, but the penetration in LS casts was unaffected by increases in linear energy. These results support the Burgardt-Heiple proposition that changes in welding parameters on penetration can be explained in terms of their effect, sequentially, on the temperature gradient and the Marangoni forces operating in the weld pool. Increases in arc length were found to decrease weld penetration regardless of the sulfur concentration of the steel, and the effects of electrode geometry and welding position on weld penetration were also investigated.

  1. Corneal Penetrating Elastin-Like Polypeptide Carriers

    PubMed Central

    George, Eric M.; Mahdi, Fakhri; Logue, Omar C.; Robinson, Grant G.

    2016-01-01

    Abstract Purpose: Elastin-like polypeptide (ELP) is a bioengineered protein widely applied as a drug carrier due to its biocompatibility and amenability to modification with cell-penetrating peptides (CPPs) and therapeutic agents. The purpose of this study was to determine whether topically applied ELP or CPP-fused ELPs penetrate the corneal barrier. Methods: In vitro binding and cytotoxicity to human corneal epithelial (HCE) cells were determined for ELP or CPP-ELPs. Corneal binding, clearance, and penetration were assessed in a rabbit model following topical application of the fluorescently labeled proteins by quantitative fluorescence imaging and histology. Results: ELP bound to HCE cells in vitro, and binding/uptake was enhanced 2- to 3-fold by the addition of CPPs. When applied topically to rabbit eyes, ELP accumulated in the cornea at levels 7.4-fold higher than did an equivalent dose of immunoglobulin G. Both ELP and a CPP-ELP penetrated the corneal epithelium and were detectable in the stroma. Addition of CPPs to ELP, however, did not significantly enhance corneal uptake or penetration in vivo relative to ELP alone. The polypeptides cleared from the cornea over a period of 20–30 min after application, after which cornea levels reached a steady state of 15–30 μg/mL for up to 3 h. Conclusions: The ELP drug carrier can penetrate the corneal epithelium and accumulate in the stroma. Given its amenability for fusion to multiple types of therapeutic agents, ELP has the potential to serve as a drug carrier for topical ocular applications. PMID:26672799

  2. Explosive shaped charge penetration into tuff rock

    SciTech Connect

    Vigil, M.G.

    1988-10-01

    Analysis and data for the use of Explosive Shaped Charges (ESC) to generate holes in tuff rock formation is presented. The ESCs evaluated include Conical Shaped Charges (CSC) and Explosive Formed Projectiles (EFP). The CSCs vary in size from 0.158 to 9.1 inches inside cone diameter. The EFPs were 5.0 inches in diameter. Data for projectile impact angles of 30 and 90 degrees are presented. Analytically predicted depth of penetration data generally compared favorably with experimental data. Predicted depth of penetration versus ESC standoff data and hole profile dimensions in tuff are also presented. 24 refs., 45 figs., 6 tabs.

  3. Optical penetration sensor for pulsed laser welding

    DOEpatents

    Essien, Marcelino; Keicher, David M.; Schlienger, M. Eric; Jellison, James L.

    2000-01-01

    An apparatus and method for determining the penetration of the weld pool created from pulsed laser welding and more particularly to an apparatus and method of utilizing an optical technique to monitor the weld vaporization plume velocity to determine the depth of penetration. A light source directs a beam through a vaporization plume above a weld pool, wherein the plume changes the intensity of the beam, allowing determination of the velocity of the plume. From the velocity of the plume, the depth of the weld is determined.

  4. Data penetration transmission in P2P

    NASA Astrophysics Data System (ADS)

    Zheng, Shiping; Feng, Xuezhi

    2007-06-01

    This paper analyzed the type of work principles of the NAT server, and by using UDP Hole Punching and port speculation technology, a program was designed to penetrate the NAT server and direct communication among the intranet users was achieved. This paper also evaluated the communications among users in various types of NAT servers, and it showed a success rate of 95%. By analyzing the principles and setting rules of firewall, together with the application of HTTP tunnel, the designed procedures have penetrated the firewall to visite the user without lowering the security level of the system. The eventual establishment of communication modules facilitated the direct peer-to-peer GIS data transmission.

  5. FREEFALL: A seabed penetrator flight code

    SciTech Connect

    Hickerson, J.

    1988-01-01

    This report presents a one-dimensional model and computer program for predicting the motion of seabed penetrators. The program calculates the acceleration, velocity, and depth of a penetrator as a function of time from the moment of launch until the vehicle comes to rest in the sediment. The code is written in Pascal language for use on a small personal computer. Results are presented as printed tables and graphs. A comparison with experimental data is given which indicates that the accuracy of the code is perhaps as good as current techniques for measuring vehicle performance. 31 refs., 12 figs., 5 tabs.

  6. Mechanics of Penetration: Analysis and Experiment

    DTIC Science & Technology

    1979-02-01

    essentially a 6 MeV x - ray source capable of shining through six inches of steel. It is invaluable for penetration studies since for the first time...data obtained with standard 150-300 KeV x - ray facilities.) Figures 7 and 8 show EPIC3 results for the same situation and Figure 9 depicts results for...for penetration and ricochet have been reviewed by ■p 03 CD CD ■P CO c ■H Xi H bO ■H •H u ■p co o oi X o 0) •p bo B E2 0) 3

  7. HMO penetration: has it hurt public hospitals?

    PubMed

    Clement, J P; Grazier, K L

    2001-01-01

    The purpose of this study is to determine the extent to which health maintenance organization (HMO) penetration within the public hospitals' market area affects the financial performance and viability of these institutions, relative to private hospitals. Hospital- and market-specific measures are examined in a fully interacted model of over 2,300 hospitals in 321 metropolitan statistical areas (MSAs) in 1995. Although hospitals located in markets with higher HMO penetration have lower financial performance as reflected in revenues, expenses and operating margin, public hospitals are not more disadvantaged than other hospitals by managed care.

  8. Corrosion Penetration in Crevices of Dental Amalgam.

    DTIC Science & Technology

    1978-09-07

    AD-AC59 301 LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CALIF PA-ETC F/6 A/S .9 CORROSION PENETRATION IN CREVICES OF DENTAL AMALGAM. (U) SEP 78 T...OF RE;-ORT & PERIOD COVERED ./CORROSION PENETRATION IN CREVICES OF _. Itm . / DENTAL AMALGAM, - . .... ,,, T 7 AUTHOR(s) / L S i DG3t1 , T. Katan and...identify by block number) amalgam corrosion, crevice corrosion, dental amalgam. 20.- ABSTRACT (Continue on reverse side If necessary and Identify by

  9. Penetrating eye injury from a metal wedge.

    PubMed

    Kozielec, G F; To, K

    1999-01-01

    The authors describe a patient with a penetrating ocular injury from a metal wedge, a common hand tool used by road service technicians for the purpose of opening a locked car door. The patient had a penetrating eye injury from a metal wedge when its sharp end released from a car door lock and retracted upward, striking the right eye. No report exists of ocular injury using a metal wedge for its intended purpose of opening a car door lock. The use of polycarbonate lenses might afford some protection.

  10. Single And Multiple Jet Penetration Experiments Into Geologic Materials

    SciTech Connect

    Kuklo, R; Murphy, M J; Rambur, T A; Switzer, L L; Summers, M A

    2003-12-19

    This paper presents the results of experiments that investigate the effect of single and multiple jet penetration into geologic materials. In previous studies of jet penetration into concrete targets, we demonstrated that an enhanced surface crater could be created by the simultaneous penetration of multiple shaped charge jets and that an enhanced target borehole could be created by the subsequent delayed penetration of a single shaped charge jet. This paper describes an extension of the multiple jet penetration research to limestone and granite.

  11. Reinventing cell penetrating peptides using glycosylated methionine sulfonium ion sequences

    SciTech Connect

    Kramer, Jessica R.; Schmidt, Nathan W.; Mayle, Kristine M.; Kamei, Daniel T.; Wong, Gerard C.L.; Deming, Timothy J.

    2015-04-15

    Cell penetrating peptides (CPPs) are intriguing molecules that have received much attention, both in terms of mechanistic analysis and as transporters for intracellular therapeutic delivery. Most CPPs contain an abundance of cationic charged residues, typically arginine, where the amino acid compositions, rather than specific sequences, tend to determine their ability to enter cells. Hydrophobic residues are often added to cationic sequences to create efficient CPPs, but typically at the penalty of increased cytotoxicity. Here, we examined polypeptides containing glycosylated, cationic derivatives of methionine, where we found these hydrophilic polypeptides to be surprisingly effective as CPPs and to also possess low cytotoxicity. X-ray analysis of how these new polypeptides interact with lipid membranes revealed that the incorporation of sterically demanding hydrophilic cationic groups in polypeptides is an unprecedented new concept for design of potent CPPs.

  12. Reinventing cell penetrating peptides using glycosylated methionine sulfonium ion sequences

    DOE PAGES

    Kramer, Jessica R.; Schmidt, Nathan W.; Mayle, Kristine M.; ...

    2015-04-15

    Cell penetrating peptides (CPPs) are intriguing molecules that have received much attention, both in terms of mechanistic analysis and as transporters for intracellular therapeutic delivery. Most CPPs contain an abundance of cationic charged residues, typically arginine, where the amino acid compositions, rather than specific sequences, tend to determine their ability to enter cells. Hydrophobic residues are often added to cationic sequences to create efficient CPPs, but typically at the penalty of increased cytotoxicity. Here, we examined polypeptides containing glycosylated, cationic derivatives of methionine, where we found these hydrophilic polypeptides to be surprisingly effective as CPPs and to also possess lowmore » cytotoxicity. X-ray analysis of how these new polypeptides interact with lipid membranes revealed that the incorporation of sterically demanding hydrophilic cationic groups in polypeptides is an unprecedented new concept for design of potent CPPs.« less

  13. Reinventing Cell Penetrating Peptides Using Glycosylated Methionine Sulfonium Ion Sequences

    PubMed Central

    2015-01-01

    Cell penetrating peptides (CPPs) are intriguing molecules that have received much attention, both in terms of mechanistic analysis and as transporters for intracellular therapeutic delivery. Most CPPs contain an abundance of cationic charged residues, typically arginine, where the amino acid compositions, rather than specific sequences, tend to determine their ability to enter cells. Hydrophobic residues are often added to cationic sequences to create efficient CPPs, but typically at the penalty of increased cytotoxicity. Here, we examined polypeptides containing glycosylated, cationic derivatives of methionine, where we found these hydrophilic polypeptides to be surprisingly effective as CPPs and to also possess low cytotoxicity. X-ray analysis of how these new polypeptides interact with lipid membranes revealed that the incorporation of sterically demanding hydrophilic cationic groups in polypeptides is an unprecedented new concept for design of potent CPPs. PMID:27162954

  14. Sub-microsecond vapor plume dynamics under different keyhole penetration regimes in deep penetration laser welding

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Pang, Shengyong; Shao, Xinyu; Wang, Chunming; Zhang, Xiaosi; Jiang, Ping; Xiao, Jianzhong

    2017-05-01

    It is well-known that distinct vapor plume dynamics occur during deep penetration laser welding under different keyhole penetration states. However, there is little knowledge about the physical characteristics of vapor plumes (velocity, pressure, flow patterns, etc) located inside transient keyholes of varying penetration regimes in laser welding. This lack of knowledge is primarily because mesoscale vapor plumes are highly dynamic and generally invisible. Based on a well-tested three-dimensional multiphase laser welding model, we conducted a computational study on vapor plume dynamics inside transient keyholes during the fiber laser welding of 304 austenite stainless steel as a function of keyhole penetration regimes. We observed three keyhole regimes of penetration: full penetration, partial penetration and no penetration. We then physically analyzed the vapor plumes in these regimes. We determined that the vapor plume velocities and pressures in all three regimes were uneven and oscillated following the dynamic keyhole with a characteristic timescale in sub-microseconds. Only when the keyhole approached the full penetration regime did vapor plumes begin to violently eject from the bottom of the keyhole opening, whereas in the partial penetration regime, even when the bottom part of the keyhole was open, most of the vapor plume ejected from the upper keyhole opening. This latter observation was similar to that in the no penetration mode. We studied the physical mechanism of this behavior by analyzing the keyhole temperature and vapor plume velocity distributions. We determined that the upward ejection of the vapor plume from the upper keyhole opening was the result of an uneven micro-meter scale boiling phenomenon of the transient keyhole governed by Fresnel absorptions dependent on the local inclination angle of the keyhole wall. Similarly, we determined that the ejection of the vapor plume from the bottom of the keyhole opening resulted from pressure

  15. Chemotactic selection of pollutant degrading soil bacteria

    DOEpatents

    Hazen, T.C.

    1991-03-04

    A method is described for identifying soil microbial strains which may be bacterial degraders of pollutants. This method includes: Placing a concentration of a pollutant in a substantially closed container; placing the container in a sample of soil for a period of time ranging from one minute to several hours; retrieving the container and collecting its contents; microscopically determining the identity of the bacteria present. Different concentrations of the pollutant can be used to determine which bacteria respond to each concentration. The method can be used for characterizing a polluted site or for looking for naturally occurring biological degraders of the pollutant. Then bacteria identified as degraders of the pollutant and as chemotactically attracted to the pollutant are used to innoculate contaminated soil. To enhance the effect of the bacteria on the pollutant, nutrients are cyclicly provided to the bacteria then withheld to alternately build up the size of the bacterial colony or community and then allow it to degrade the pollutant.

  16. Penetration profile of microspheres in follicular targeting of terminal hair follicles.

    PubMed

    Toll, R; Jacobi, U; Richter, H; Lademann, J; Schaefer, H; Blume-Peytavi, U

    2004-07-01

    The transfollicular administration of pharmacologically active molecules is of current therapeutic interest, mainly with regard to delivery to specific sites of the hair follicle (HF) and the reduction of hepatic metabolism and systemic toxicity. HF are privileged pathways for specific molecules depending on formulations, which enter faster into these shunts than through the stratum corneum. The aim was to optimize the delivery of fluorescent microspheres into the HF, thereby, developing a standardized protocol for follicular targeting with microspheres. The number of HF showing penetration, as well as the depth of penetration, was determined. Freshly excised skin samples with terminal HF were divided into groups, with or without prior treatment with cyanoacrylate skin surface stripping-technique (CSSS). Thereafter microspheres at a size of 0.75-6.0 microm were applied according to the developed standardized protocol. Skin biopsies were obtained, shock-frozen, and sectioned in 5 microm slices. We demonstrated a selective penetration route of the microspheres into the HF. Optimal microsphere size proved to be approximately 1.5 microm, with a 55% rate of all HF, and with a maximum penetration depth of >2300 microm. Without previous CSSS treatment of the skin, the transfollicular microsphere penetration was below 27% with a maximum penetration depth of 1000 microm. Thus, the basis for follicular targeting of essential structures containing stem cells for keratinocytes, melanocytes, and mast cells has been laid.

  17. Grain Boundary Penetration of Various Types of Ni Layer by Molten Metals

    NASA Astrophysics Data System (ADS)

    Yang, S.; Chang, C. Y.; Zhu, Z. X.; Lin, Y. F.; Kao, C. R.

    2017-07-01

    The grain boundary penetration of three types of Ni layer, Ni foil, electroplated Ni, and electroless Ni, by molten Pb and 95Pb5Sn (wt.%) is investigated. The average grain sizes of Ni foil and electroplated Ni are 10 μm and 1 μm, respectively, while the electroless Ni is amorphous. The purpose of using two molten metals is to study the effect of intermetallic formation on grain boundary penetration. Molten Pb was able to penetrate or disintegrate all three types of Ni, including amorphous Ni, which does not contain any grain boundaries. On the other hand, the addition of merely 5 wt.% Sn into molten Pb was able to slow the penetration down substantially for all three types of Ni layer, with the greatest suppression found in electroless Ni where a grain boundary penetration event did not take place. The mechanism for the Sn effect is due to the formation of a protective Ni3Sn4 intermetallic compound at the interface acting as a barrier against grain boundary penetration.

  18. Grain Boundary Penetration of Various Types of Ni Layer by Molten Metals

    NASA Astrophysics Data System (ADS)

    Yang, S.; Chang, C. Y.; Zhu, Z. X.; Lin, Y. F.; Kao, C. R.

    2017-02-01

    The grain boundary penetration of three types of Ni layer, Ni foil, electroplated Ni, and electroless Ni, by molten Pb and 95Pb5Sn (wt.%) is investigated. The average grain sizes of Ni foil and electroplated Ni are 10 μm and 1 μm, respectively, while the electroless Ni is amorphous. The purpose of using two molten metals is to study the effect of intermetallic formation on grain boundary penetration. Molten Pb was able to penetrate or disintegrate all three types of Ni, including amorphous Ni, which does not contain any grain boundaries. On the other hand, the addition of merely 5 wt.% Sn into molten Pb was able to slow the penetration down substantially for all three types of Ni layer, with the greatest suppression found in electroless Ni where a grain boundary penetration event did not take place. The mechanism for the Sn effect is due to the formation of a protective Ni3Sn4 intermetallic compound at the interface acting as a barrier against grain boundary penetration.

  19. Identification of HRAS mutations and absence of GNAQ or GNA11 mutations in deep penetrating nevi.

    PubMed

    Bender, Ryan P; McGinniss, Matthew J; Esmay, Paula; Velazquez, Elsa F; Reimann, Julie Dr

    2013-10-01

    HRAS is mutated in ∼15% of Spitz nevi, and GNAQ or GNA11 is mutated in blue nevi (46-83% and ∼7% respectively). Epithelioid blue nevi and deep penetrating nevi show features of both blue nevi (intradermal location, pigmentation) and Spitz nevi (epithelioid morphology). Epithelioid blue nevi and deep penetrating nevi can also show overlapping features with melanoma, posing a diagnostic challenge. Although epithelioid blue nevi are considered blue nevic variants, no GNAQ or GNA11 mutations have been reported. Classification of deep penetrating nevi as blue nevic variants has also been proposed, however, no GNAQ or GNA11 mutations have been reported and none have been tested for HRAS mutations. To better characterize these tumors, we performed mutational analysis for GNAQ, GNA11, and HRAS, with blue nevi and Spitz nevi as controls. Within deep penetrating nevi, none demonstrated GNAQ or GNA11 mutations (0/38). However, 6% revealed HRAS mutation (2/32). Twenty percent of epithelioid blue nevi contained a GNAQ mutation (2/10), while none displayed GNA11 or HRAS mutation. Eighty-seven percent of blue nevi contained a GNAQ mutation (26/30), 4% a GNA11 mutation (1/28), and none an HRAS mutation. Within Spitz nevi, none demonstrated GNAQ or GNA11 mutations (0/30). Seventeen percent contained an HRAS mutation (5/30). All GNAQ and GNA11 mutations were p.Q209L (c.626A>T) point mutations, except 2 GNAQ mutations, which contained novel c.625_626CA>TT double mutations. Four HRAS mutations were in exon 2, and three in exon 3. This is the first study to identify HRAS mutations in deep penetrating nevi. The presence of HRAS mutations and absence of GNAQ or GNA11 mutations in deep penetrating nevi suggests classification of these unusual nevi within the Spitz nevus category of melanocytic tumors, rather than the blue nevus category.

  20. Surface-Adaptive, Antimicrobially Loaded, Micellar Nanocarriers with Enhanced Penetration and Killing Efficiency in Staphylococcal Biofilms.

    PubMed

    Liu, Yong; Busscher, Henk J; Zhao, Bingran; Li, Yuanfeng; Zhang, Zhenkun; van der Mei, Henny C; Ren, Yijin; Shi, Linqi

    2016-04-26

    Biofilms cause persistent bacterial infections and are extremely recalcitrant to antimicrobials, due in part to reduced penetration of antimicrobials into biofilms that allows bacteria residing in the depth of a biofilm to survive antimicrobial treatment. Here, we describe the preparation of surface-adaptive, Triclosan-loaded micellar nanocarriers showing (1) enhanced biofilm penetration and accumulation, (2) electrostatic targeting at acidic pH toward negatively charged bacterial cell surfaces in a biofilm, and (3) antimicrobial release due to degradation of the micelle core by bacterial lipases. First, it was established that mixed-shell-polymeric-micelles (MSPM) consisting of a hydrophilic poly(ethylene glycol) (PEG)-shell and pH-responsive poly(β-amino ester) become positively charged at pH 5.0, while being negatively charged at physiological pH. This is opposite to single-shell-polymeric-micelles (SSPM) possessing only a PEG-shell and remaining negatively charged at pH 5.0. The stealth properties of the PEG-shell combined with its surface-adaptive charge allow MSPMs to penetrate and accumulate in staphylococcal biofilms, as demonstrated for fluorescent Nile red loaded micelles using confocal-laser-scanning-microscopy. SSPMs, not adapting a positive charge at pH 5.0, could not be demonstrated to penetrate and accumulate in a biofilm. Once micellar nanocarriers are bound to a staphylococcal cell surface, bacterial enzymes degrade the MSPM core to release its antimicrobial content and kill bacteria over the depth of a biofilm. This constitutes a highly effective pathway to control blood-accessible staphylococcal biofilms using antimicrobials, bypassing biofilm recalcitrance to antimicrobial penetration.

  1. Hydrocarbon degradation by antarctic bacteria

    SciTech Connect

    Cavanagh, J.A.E.; Nichols, P.D.; McMeekin, T.A.; Franzmann, P.D.

    1996-12-31

    Bacterial cultures obtained from sediment samples collected during a trial oil spill experiment conducted at Airport beach, Eastern Antarctica were selectively enriched for n-alkane-degrading and phenanthrenedegrading bacteria. Samples were collected from a control site and sites treated with different hydrocarbon mixtures - Special Antarctic blend (SAB), BP-Visco and orange roughy oils. One set of replicate sites was also treated with water from Organic Lake which had previously been shown to contain hydrocarbon-degrading bacteria. No viable bacteria were obtained from samples collected from sites treated with orange roughy oil. Extensive degradation of n-alkanes by enrichment cultures obtained from sites treated with SAB and BP-Visco occurred at both 25{degrees}C and 10{degrees}C. Extensive degradation of phenanthrene also occurred in enrichment cultures from these sites grown at 25{degrees}C. Concurrent increases of polar lipid in these cultures were also observed. The presence of 1,4-naphthaquinone and 1-naphthol during the growth of the cultures on phenanthrene is unusual and warrants further investigation of the mechanism of phenanthrene-degradation by these Antarctic bacteria.

  2. Nuclear factor-κB-inducing kinase (NIK) contains an amino-terminal inhibitor of apoptosis (IAP)-binding motif (IBM) that potentiates NIK degradation by cellular IAP1 (c-IAP1).

    PubMed

    Lee, Sunhee; Challa-Malladi, Madhavi; Bratton, Shawn B; Wright, Casey W

    2014-10-31

    Activation of the noncanonical NF-κB pathway hinges on the stability of the NF-κB-inducing kinase (NIK), which is kept at low levels basally by a protein complex consisting of the E3 ubiquitin ligases cellular inhibitor of apoptosis 1 and 2 (c-IAP1/2) proteins and the tumor necrosis factor receptor-associated factors 2 and 3 (TRAF2/3). NIK is brought into close proximity to the c-IAPs through a TRAF2-TRAF3 bridge where TRAF2 recruits c-IAP1/2 and TRAF3 binds to NIK. However, it is not clear how the c-IAPs specifically recognize and ubiquitylate NIK in the complex. We have identified an IAP-binding motif (IBM) at the amino terminus of NIK. IBMs are utilized by a number of proapoptotic proteins to antagonize IAP function. Here, we utilize mutational studies to demonstrate that wild-type NIK is destabilized in the presence of c-IAP1, whereas the NIK IBM mutant is stable. NIK interacts with the second baculovirus IAP repeat (BIR2) domain of c-IAP1 via the IBM, and this interaction, in turn, provides substrate recognition for c-IAP1 mediated ubiquitylation and degradation of NIK. Furthermore, in the presence of the NIK IBM mutant, we observed an elevated processing of p100 to p52 followed by increased expression of NF-κB target genes. Together, these findings reveal the novel identification and function of the NIK IBM, which promotes c-IAP1-dependent ubiquitylation of NIK, resulting in optimal NIK turnover to ensure that noncanonical NF-κB signaling is off in the absence of an activating signal. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Nuclear Factor-κB-inducing Kinase (NIK) Contains an Amino-terminal Inhibitor of Apoptosis (IAP)-binding Motif (IBM) That Potentiates NIK Degradation by Cellular IAP1 (c-IAP1)*

    PubMed Central

    Lee, Sunhee; Challa-Malladi, Madhavi; Bratton, Shawn B.; Wright, Casey W.

    2014-01-01

    Activation of the noncanonical NF-κB pathway hinges on the stability of the NF-κB-inducing kinase (NIK), which is kept at low levels basally by a protein complex consisting of the E3 ubiquitin ligases cellular inhibitor of apoptosis 1 and 2 (c-IAP1/2) proteins and the tumor necrosis factor receptor-associated factors 2 and 3 (TRAF2/3). NIK is brought into close proximity to the c-IAPs through a TRAF2-TRAF3 bridge where TRAF2 recruits c-IAP1/2 and TRAF3 binds to NIK. However, it is not clear how the c-IAPs specifically recognize and ubiquitylate NIK in the complex. We have identified an IAP-binding motif (IBM) at the amino terminus of NIK. IBMs are utilized by a number of proapoptotic proteins to antagonize IAP function. Here, we utilize mutational studies to demonstrate that wild-type NIK is destabilized in the presence of c-IAP1, whereas the NIK IBM mutant is stable. NIK interacts with the second baculovirus IAP repeat (BIR2) domain of c-IAP1 via the IBM, and this interaction, in turn, provides substrate recognition for c-IAP1 mediated ubiquitylation and degradation of NIK. Furthermore, in the presence of the NIK IBM mutant, we observed an elevated processing of p100 to p52 followed by increased expression of NF-κB target genes. Together, these findings reveal the novel identification and function of the NIK IBM, which promotes c-IAP1-dependent ubiquitylation of NIK, resulting in optimal NIK turnover to ensure that noncanonical NF-κB signaling is off in the absence of an activating signal. PMID:25246529

  4. Prediction of Weld Penetration in FCAW of HSLA steel using Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Asl, Y. Dadgar; Mostafa, N. B.; Panahizadeh R., V.; Seyedkashi, S. M. H.

    2011-01-01

    Flux-cored arc welding (FCAW) is a semiautomatic or automatic arc welding process that requires a continuously-fed consumable tubular electrode containing a flux. The main FCAW process parameters affecting the depth of penetration are welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed. Shallow depth of penetration may contribute to failure of a welded structure since penetration determines the stress-carrying capacity of a welded joint. To avoid such occurrences; the welding process parameters influencing the weld penetration must be properly selected to obtain an acceptable weld penetration and hence a high quality joint. Artificial neural networks (ANN), also called neural networks (NN), are computational models used to express complex non-linear relationships between input and output data. In this paper, artificial neural network (ANN) method is used to predict the effects of welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed on weld penetration depth in gas shielded FCAW of a grade of high strength low alloy steel. 32 experimental runs were carried out using the bead-on-plate welding technique. Weld penetrations were measured and on the basis of these 32 sets of experimental data, a feed-forward back-propagation neural network was created. 28 sets of the experiments were used as the training data and the remaining 4 sets were used for the testing phase of the network. The ANN has one hidden layer with eight neurons and is trained after 840 iterations. The comparison between the experimental results and ANN results showed that the trained network could predict the effects of the FCAW process parameters on weld penetration adequately.

  5. Prediction of Weld Penetration in FCAW of HSLA steel using Artificial Neural Networks

    SciTech Connect

    Asl, Y. Dadgar; Mostafa, N. B.; Panahizadeh, V. R.; Seyedkashi, S. M. H.

    2011-01-17

    Flux-cored arc welding (FCAW) is a semiautomatic or automatic arc welding process that requires a continuously-fed consumable tubular electrode containing a flux. The main FCAW process parameters affecting the depth of penetration are welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed. Shallow depth of penetration may contribute to failure of a welded structure since penetration determines the stress-carrying capacity of a welded joint. To avoid such occurrences; the welding process parameters influencing the weld penetration must be properly selected to obtain an acceptable weld penetration and hence a high quality joint. Artificial neural networks (ANN), also called neural networks (NN), are computational models used to express complex non-linear relationships between input and output data. In this paper, artificial neural network (ANN) method is used to predict the effects of welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed on weld penetration depth in gas shielded FCAW of a grade of high strength low alloy steel. 32 experimental runs were carried out using the bead-on-plate welding technique. Weld penetrations were measured and on the basis of these 32 sets of experimental data, a feed-forward back-propagation neural network was created. 28 sets of the experiments were used as the training data and the remaining 4 sets were used for the testing phase of the network. The ANN has one hidden layer with eight neurons and is trained after 840 iterations. The comparison between the experimental results and ANN results showed that the trained network could predict the effects of the FCAW process parameters on weld penetration adequately.

  6. Enhancement Of Penetrant-Inspection Images

    NASA Technical Reports Server (NTRS)

    Wilson, Rhonda C.

    1990-01-01

    Proposed computerized video system processes images of fluorescent dyes absorbed in flaws in welds. Video camera, held by operator or by remote manipulator, views weld illuminated by visible white and ultraviolet light. Images of penetrating dye in cracks and voids in weld joint appear on video monitor. Fluorescent features enhanced by software to facilitate identification of true flaws and record important data.

  7. Computed tomographic findings in penetrating peptic ulcer

    SciTech Connect

    Madrazo, B.L.; Halpert, R.D.; Sandler, M.A.; Pearlberg, J.L.

    1984-12-01

    Four cases of peptic ulcer penetrating the head of the pancreas were diagnosed by computed tomography (CT). Findings common to 3 cases included (a) an ulcer crater, (b) a sinus tract, and (c) enlargement of the head of the pancreas. Unlike other modalities, the inherent spatial resolution of CT allows a convenient diagnosis of this important complication of peptic ulcer disease.

  8. Sealing Penetrating Eye Injuries With Photoactivated Bonding

    DTIC Science & Technology

    2010-09-01

    linking in response to treatment with topical riboflavin and long-wavelength ultraviolet radiation (UVA). Investigative ophthalmology & visual science...in warfighters sustaining penetrating eye injuries. Scope: In year 1, the scope was to establish the treatment parameters for sealing amniotic...established safe limits. Major findings: We identified the treatment parameters (amnion patch size, dye concentration, dye staining time and the

  9. On the penetration of fast charged particles.

    PubMed

    Perry, D J

    1988-07-01

    We pursue Yang's multiple scattering analysis and develop a wave description of electron penetration which permits the calculation of spatial distributions under realistic conditions. We give special emphasis to the longitudinal part of the problem and illustrate with sample calculations of particular interest to medical physicists.

  10. Subsurface investigation with ground penetrating radar

    USDA-ARS?s Scientific Manuscript database

    Ground penetrating radar (GPR) data was collected on a small test plot at the OTF/OSU Turfgrass Research & Education Facility in Columbus, Ohio. This test plot was built to USGA standards for a golf course green, with a constructed sand layer just beneath the surface overlying a gravel layer, that i...

  11. Penetration and haptenation of p-phenylenediamine.

    PubMed

    Pot, Laura M; Scheitza, Simone M; Coenraads, Pieter-Jan; Blömeke, Brunhilde

    2013-04-01

    Although p-phenylenediamine (PPD) has been recognized as an extreme sensitizer for many years, the exact mechanism of sensitization has not been elucidated yet. Penetration and the ability to bind to proteins are the first two hurdles that an allergen has to overcome to be able to sensitize. This review is an overview of studies regarding PPD penetration through skin (analogues) and studies on the amino acids that are targeted by PPD. To complete this review, the auto-oxidation and N-acetylation steps involved in PPD metabolism are described. In summary, under normal hair dyeing exposure conditions, <1% of the applied PPD dose penetrates the skin. The majority (>80%) of PPD that penetrates will be converted into the detoxification products monoacetyl-PPD and diacetyl-PPD by the N-acetyltransferase enzymes. The small amount of PPD that does not become N-acetylated is susceptible to auto-oxidation reactions, yielding protein-reactive PPD derivatives. These derivatives may bind to specific amino acids, and some of the formed adducts might be the complexes responsible for sensitization. However, true in vivo evidence is lacking, and further research to unravel the definite mechanism of sensitization is needed. © 2013 John Wiley & Sons A/S.

  12. Excimer laser mushroom penetrating keratoplasty: new technique.

    PubMed

    Della Valle, Vincenzo; Bonci, Paolo

    2014-01-01

    To evaluate retrospectively the outcomes of 15 consecutive mushroom-shaped penetrating keratoplasties performed by using excimer laser for both the recipient bed and the fresh donor corneas. Fifteen eyes of 14 patients who underwent excimer laser mushroom-shaped penetrating keratoplasty from October 13, 2010, to October 14, 2011, were included in our retrospective study. Eight were men and 6 were women, with a mean age of 31.45 ± 6.52 (range 27-65) years. Eleven (73.3%) had postinfective central deep corneal scar; 4 (26.7%) had severe keratoconus with Descemet opacity. The mean follow-up was 11.9 ± 2.7 months. The mean preoperative best-corrected visual acuity (BCVA) was 0.15 ± 0.16; the postoperative BCVA was 0.69 ± 0.24 after 12 months with a mean refractive astigmatism of 1.8 ± 1.1 D. The mean preoperative endothelial cell count of the donor corneas was 2297.0 ± 189.7 cells/mm²; after 12 months, it was 1906.5 ± 165.8 with a decrease of 17.0%. No intraoperative complications occurred. Our results showed that excimer laser mushroom penetrating keratoplasty is safe. Furthermore, it does not appear to influence the visual outcomes of the penetrating keratoplasty surgery. This technique is useful for those who use an excimer laser.

  13. Sealing Penetrating Eye Injuries Using Photoactivated Bonding

    DTIC Science & Technology

    2011-09-01

    skin requires specialized training to precisely place hair- fine sutures and requires long surgery time. Cyanoacrylate glues can complicate further... cyanoacrylate glues can cause damage upon removal and interfere with subsequent surgery. In Year 2 (Kochever) we established that lacerations in thin... glue was not competitive with PTB for sealing is amnion over penetrating cornea injuries, determined that two potential adverse effects

  14. Scattering from inhomogeneous penetrable bodies of revolution

    NASA Astrophysics Data System (ADS)

    Govind, S.; Wilton, D. R.; Glisson, A. W.

    1984-11-01

    A systematic procedure for studying scattering from inhomogeneous penetrable bodies in which the inhomogeneity is modeled by piecewise homogeneous layers, is presented. The procedure utilizes the block tridiagonal property of the system matrix to simplify the computations and is applied to examples of dielectric bodies of revolution. An extension of the technique permits the solution of a composite missile/plume scattering problem.

  15. Good penetration of moxifloxacin into human abscesses.

    PubMed

    Sauermann, Robert; Karch, Rudolf; Kjellsson, Maria C; Feurstein, Thomas; Püspök, Andreas; Langenberger, Herbert; Böhmdorfer, Michaela; Jäger, Walter; Zeitlinger, Markus

    2012-01-01

    Abscesses are often treated with antibiotics in addition to incision or when incision is unfeasible, but accurate information about antibiotic abscess penetration in humans is missing. This study aimed at evaluating the penetration of moxifloxacin into human abscesses. After administration of a single dose of 400 mg moxifloxacin, drug concentrations were measured in 10 differently located abscesses at incision, and in plasma over 8 h. At incision performed 0.9-4.8 h after administration, moxifloxacin concentrations in abscesses ranged from ≤0.01 to 9.2 mg/l (1.9 ± 3.4 mg/l), indicating pronounced drug accumulation in some abscesses. The degree of abscess penetration could not be explained by covariates like the ratio of surface area to volume or pH of abscesses, or by moxifloxacin plasma concentrations. Concluding, moxifloxacin was detectable in most abscesses and may be a useful antibiotic for this indication. However, antibiotic abscess penetration was highly variable and unpredictable, suggesting surgical abscess incision whenever possible.

  16. Sharps container

    NASA Technical Reports Server (NTRS)

    Lee, Angelene M. (Inventor)

    1992-01-01

    This invention relates to a system for use in disposing of potentially hazardous items and more particularly a Sharps receptacle for used hypodermic needles and the like. A Sharps container is constructed from lightweight alodined nonmagnetic metal material with a cup member having an elongated tapered shape and length greater than its transverse dimensions. A magnet in the cup member provides for metal retention in the container. A nonmagnetic lid member has an opening and spring biased closure flap member. The flap member is constructed from stainless steel. A Velcro patch on the container permits selective attachment at desired locations.

  17. Penetration enhancing effects of selected natural oils utilized in topical dosage forms.

    PubMed

    Viljoen, Joe M; Cowley, Amé; du Preez, Jan; Gerber, Minja; du Plessis, Jeanetta

    2015-01-01

    Various natural products, including oils, have been utilized as penetration enhancers due to their "safety profiles". These oils contain fatty acids promoting skin permeability through lipid fluidization within the stratum corneum; and might therefore be able to effectively enhance transdermal drug delivery. We investigated possible penetration enhancing properties of selected oils, utilizing flurbiprofen as marker compound in emulgel formulations. The formulations were compared to a liquid paraffin emulgel and a hydrogel to establish any significant penetration enhancing effects. Gas chromatographic analysis of the natural oils was performed at ambient temperature to determine the fatty acid composition in each selected natural oils. Franz cell diffusion studies and tape stripping methods were employed to study delivery of the marker into, and through the skin. The following rank order for the emulgel flux-values was obtained: Hydrogel > olive oil > liquid paraffin > coconut oil > grape seed oil > Avocado oil ≥ Crocodile oil > Emu oil. Results suggested that oils containing predominantly mono-unsaturated oleic acid, on average increased the flux of the marker to a larger extent than oils containing an almost even mixture of both mono- and poly-unsaturated fatty acids. Oils comprising saturated fatty acids (SFAs) with alkyl chains between C12 and C14, increased the marker flux to a higher extent than oils containing C16-C18 SFAs. Effects observed for branched fatty acids, however, did not vary significantly from effects for unbranched fatty acids with the same carbon chain length. Natural oils possess penetration enhancing effects.

  18. A new penetration test method: protection efficiency of glove and clothing materials against diphenylmethane diisocyanate (MDI).

    PubMed

    Henriks-Eckerman, Maj-Len; Mäkelä, Erja

    2015-03-01

    Reported cases of allergic contact dermatitis caused by methylenediphenyl diisocyanate (MDI) have increased and thereby increased the need for adequate skin protection. Current standardized permeation and penetration test methods give information about efficacy of protective materials against individual components of the polyurethane systems. They do not give information of what kind of clothing materials workers should wear against splashes when handling mixed MDI-polyurethane formulations, which contain MDI, its oligomers, and polyols. The aim of this study was to develop and validate a sensitive penetration test method that can be used to select clothing that is protective enough against uncured splashes of MDI-polyurethane, still easy to use, and also, to find affordable glove materials that provide adequate protection during a short contact. The penetration of MDI through eight representative glove or clothing materials was studied with the developed test procedure. One MDI hardener and two polymeric MDI (PMDI)-polyol formulations representing different curing times were used as test substances. The materials tested included work clothing (woven) fabric, arm shields (nonwoven fabric), old T-shirt, winter gloves, and gloves of nitrile rubber, leather, vinyl (PVC), and natural rubber. A drop (50 µl) of test substance was added to the outer surface of the glove/clothing material, which had Tape Fixomull attached to the inner surface as a collection medium. After penetration times of 5 or 20min, the collecting material was removed and immediately immersed into acetonitrile containing 1-(2-methoxyphenyl)-piperazine for derivatization. The formed urea derivatives of 2,4'-MDI and 4,4'-MDI were analysed using liquid chromatography with mass spectrometric and UV detection. The precision of the test method was good for the material with high penetration (work clothing fabric) of MDI, as the relative standard deviation (RSD) was 14 and 20%. For the arm shield with a low

  19. Container Routes

    ERIC Educational Resources Information Center

    Dagnall, W.

    1974-01-01

    On a triangular grid of equilateral triangles an analytical procedure is presented for solving puzzles that require one to measure out a specified amount of liquid from containers of various volumes. (JP)

  20. Laryngeal penetration during deglutition in normal subjects of various ages.

    PubMed

    Daggett, Alicia; Logemann, Jeri; Rademaker, Alfred; Pauloski, Barbara

    2006-10-01

    This study examined the frequency of penetration of liquid, paste, and masticated materials into the airway during videofluoroscopic studies of normal swallow in 98 normal subjects who were from 20 to 94 years of age. The purposes of the study were to define frequency and level of penetration using the penetration-aspiration scale as a result of age, bolus volume, viscosity, and gender, and to describe the body's sensorimotor response to the penetration based on audible coughs or throat clearing on the audio channel of each videotaped fluoroscopic study. Frequencies of penetration were defined in relation to bolus volume, age, gender, and bolus viscosity from swallows of 1, 3, 5, and 10 ml and cup-drinking of thin liquids; 3 ml of pudding; (1/4) of a Lorna Doone cookie; and a bite of an apple. Results showed that penetrations were significantly more frequent after age 50 and thick viscosities penetrated only in subjects age 50 and over. For persons under 50, 7.4% of swallows exhibited penetration, while for people age 50 and over, 16.8% of swallows showed penetration. Significantly more penetration occurred on larger liquid boluses. There was no relationship between gender and frequency of penetration. None of the subjects that penetrated showed a sensorimotor response to the penetration, which may relate to the relatively shallow depth of the penetration.