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Sample records for injectable rapid gelling

  1. Injection dynamics of gelled propellants

    NASA Astrophysics Data System (ADS)

    Yoon, Changjin

    Gel propellants have been recognized as attractive candidates for future propulsion systems due to the reduced tendency to spill and the energy advantages over solid propellants. One of strong benefits emphasized in gel propellant applications is a throttling capability, but the accurate flow control is more complicated and difficult than with conventional Newtonian propellants because of the unique rheological behaviors of gels. This study is a computational effort directed to enhance understanding of the injector internal flow characteristics for gel propellants under rocket injection conditions. In simulations, the emphasized rheology is a shear-thinning which represents a viscosity decrease with increasing a shear rate. It is described by a generalized Newtonian fluid constitutive equation and Carreau-Yasuda model. Using this rheological model, two injection schemes are considered in the present study: axially-fed and cross-fed injection for single-element and multi-element impinging injectors, respectively. An axisymmetric model is developed to describe the axially-fed injector flows and fully three-dimensional model is utilized to simulate cross-fed injector flows. Under axially-fed injection conditions investigated, three distinct modes, an unsteady, steady, and hydraulic flip mode, are observed and mapped in terms of Reynolds number and orifice design. In an unsteady mode, quasi-periodic oscillations occur near the inlet lip leading mass pulsations and viscosity fluctuations at the orifice exit. This dynamic behavior is characterized using a time-averaged discharge coefficient, oscillation magnitude and frequency by a parametric study with respect to an orifice design, Reynolds number and rheology. As a result, orifice exit flows for gel propellants appear to be significantly influenced by a viscous damping and flow resistance due to a shear thinning behavior and these are observed in each factors considered. Under conditions driven by a manifold crossflow

  2. Structure-Property Evaluation of Thermally and Chemically Gelling Injectable Hydrogels for Tissue Engineering

    PubMed Central

    Ekenseair, Adam K.; Boere, Kristel W. M.; Tzouanas, Stephanie N.; Vo, Tiffany N.; Kasper, F. Kurtis; Mikos, Antonios G.

    2012-01-01

    The impact of synthesis and solution formulation parameters on the swelling and mechanical properties of a novel class of thermally and chemically gelling hydrogels combining poly(N-isopropylacrylamide)-based thermogelling macromers containing pendant epoxy rings with polyamidoamine-based hydrophilic and degradable diamine crosslinking macromers was evaluated. Through variation of network hydrophilicity and capacity for chain rearrangement, the often problematic tendency of thermogelling hydrogels to undergo significant syneresis was addressed. The demonstrated ability to easily tune post-formation dimensional stability at both the synthesis and formulation stages represents a significant novel contribution towards efforts to utilize poly(N-isopropylacrylamide)-based polymers as injectable biomaterials. Furthermore, the cytocompatibility of the hydrogel system under relevant conditions was established, while demonstrating time- and dose-dependent cytotoxicity at high solution osmolality. Such injectable in situ forming degradable hydrogels with tunable water content are promising candidates for many tissue engineering applications, particularly for cell delivery to promote rapid tissue regeneration in non-load-bearing defects. PMID:22881074

  3. Liquid and gelled sprays for mixing hypergolic propellants using an impinging jet injection system

    NASA Astrophysics Data System (ADS)

    James, Mark D.

    The characteristics of sprays produced by liquid rocket injectors are important in understanding rocket engine ignition and performance. The includes, but is not limited to, drop size distribution, spray density, drop velocity, oscillations in the spray, uniformity of mixing between propellants, and the spatial distribution of drops. Hypergolic ignition and the associated ignition delay times are also important features in rocket engines, providing high reliability and simplicity of the ignition event. The ignition delay time is closely related to the level and speed of mixing between a hypergolic fuel and oxidizer, which makes the injection method and conditions crucial in determining the ignition performance. Although mixing and ignition of liquid hypergolic propellants has been studied for many years, the processes for injection, mixing, and ignition of gelled hypergolic propellants are less understood. Gelled propellants are currently under investigation for use in rocket injectors to combine the advantages of solid and liquid propellants, although not without their own difficulties. A review of hypergolic ignition has been conducted for selected propellants, and methods for achieving ignition have been established. This research is focused on ignition using the liquid drop-on-drop method, as well as the doublet impinging jet injector. The events leading up to ignition, known as pre-ignition stage are discussed. An understanding of desirable ignition and combustion performance requires a study of the effects of injection, temperature, and ambient pressure conditions. A review of unlike-doublet impinging jet injection mixing has also been conducted. This includes mixing factors in reactive and non-reactive sprays. Important mixing factors include jet momentum, jet diameter and length, impingement angle, mass distribution, and injector configuration. An impinging jet injection system is presented using an electro-mechanically driven piston for injecting liquid

  4. Injectable Dual-Gelling Cell-Laden Composite Hydrogels for Bone Tissue Engineering

    PubMed Central

    Vo, T.N.; Shah, S.R.; Lu, S.; Tatara, A.M.; Lee, E.J.; Roh, T.T.; Tabata, Y.; Mikos, A.G.

    2016-01-01

    The present work investigated the osteogenic potential of injectable, dual thermally and chemically gelable composite hydrogels for mesenchymal stem cell (MSC) delivery in vitro and in vivo. Composite hydrogels comprising copolymer macromers of N-isopropylacrylamide were fabricated through the incorporation of gelatin microparticles (GMPs) as enzymatically digestible porogens and sites for cellular attachment. High and low polymer content hydrogels with and without GMP loading were shown to successfully encapsulate viable MSCs and maintain their survival over 28 days in vitro. GMP incorporation was also shown to modulate alkaline phosphatase production, but enhanced hydrogel mineralization along with higher polymer content even in the absence of cells. Moreover, the regenerative capacity of 2 mm thick hydrogels with GMPs only, MSCs only, or GMPs and MSCs was evaluated in vivo in an 8 mm rat critical size cranial defect for 4 and 12 weeks. GMP incorporation led to enhanced bony bridging and mineralization within the defect at each timepoint, and direct bone-implant contact as determined by microcomputed tomography and histological scoring, respectively. Encapsulation of both GMPs and MSCs enabled hydrogel degradation leading to significant tissue infiltration and osteoid formation. The results suggest that these injectable, dual-gelling cell-laden composite hydrogels can facilitate bone ingrowth and integration, warranting further investigation for bone tissue engineering. PMID:26773659

  5. Injectable pectin hydrogels produced by internal gelation: pH dependence of gelling and rheological properties.

    PubMed

    Moreira, Helena R; Munarin, Fabiola; Gentilini, Roberta; Visai, Livia; Granja, Pedro L; Tanzi, Maria Cristina; Petrini, Paola

    2014-03-15

    The production of injectable pectin hydrogels by internal gelation with calcium carbonate is proposed. The pH of pectin was increased with NaOH or NaHCO3 to reach physiological values. The determination of the equivalence point provided evidence that the pH can be more precisely modulated with NaHCO3 than with NaOH. Degradation and inability to gel was observed for pectin solutions with pH 5.35 or higher. Therefore, pectin solutions with pH values varying from 3.2 (native pH) to 3.8 were chosen to produce the gels. The increase of the pH for the crosslinked hydrogels, as well as the reduction of the gelling time and their thickening, was dependent upon the amount of calcium carbonate, as confirmed by rheology. Hydrogel extracts were not cytotoxic for L-929 fibroblasts. On the overall, the investigated formulations represent interesting injectable systems providing an adequate microenvironment for cell, drug or bioactive molecules delivery.

  6. An Injectable and In Situ-Gelling Biopolymer for Sustained Drug Release Following Perineural Administration

    PubMed Central

    Shamji, Mohammed F.; Whitlatch, Lyman; Friedman, Allan H.; Richardson, William J.; Chilkoti, Ashutosh; Setton, Lori A.

    2009-01-01

    Study Design This study evaluated whether the aggregation behavior of a thermally responsive elastin-like polypeptide (ELP) prolongs protein residence time at the dorsal root ganglion (DRG). This work involves development of a sustained-release drug delivery vehicle to provide high and sustained levels of biologic therapeutics to the dorsal root ganglion while minimizing systemic exposure. Objective To study the potential of the ELP biopolymer to sustain release and lower systemic exposure of bioactive peptides following perineural administration. Summary of Background Data Anticytokine treatment for lumbar radiculopathy may offer clinical improvement, but exposes patients to systemic toxicities of immunosuppression. ELPs are environmentally responsive polypeptides that undergo a phase transition on heating to form an insoluble aggregate. Drug conjugates with ELP exhibit both temperature-sensitivity and in vitro bioactivity. Monomer resolubilization yields solution-phase molecules, and this reversible aggregation behavior may create a perineural drug depot to sustain drug delivery to an inflamed nerve. Methods This experiment involved 48 rats in which radiolabeled ELPs (aggregating or soluble) were injected overlying the L5 dorsal root ganglion. Animals were killed at 6 different time points, and radioactivity associated with the injected segment, serum, and other tissues was evaluated. Results The aggregating ELP demonstrated a 7-fold longer perineural half-life compared with the soluble ELP. This supports the hypothesis that the aggregating ELP forms a depot from which slow resolubilization and clearance provides sustained, local protein release. Furthermore, serum radioactivity reached a lower peak for the aggregating group, demonstrating slower absorption of the aggregating protein into the systemic circulation. Conclusion These results suggest that ELP aggregation confer the benefit of perineural compartment longevity for bioactive therapeutics delivered fused

  7. A novel, simple method to simulate gelling process of injectable biodegradable in situ forming drug delivery system based on determination of electrical conductivity.

    PubMed

    Wang, Keke; Jia, Qiang; Yuan, Jing; Li, Sanming

    2011-02-14

    The purpose of the present study was to develop a novel, simple and determination-of-electrical-conductivity-based method to trace the gelling process of injectable biodegradable in situ forming organogels after administration. The electrical conductivity of pH 7.4 PBS solution with different amount of N-methyl-2-pyrrolodone (NMP) and drug-free organogel formulation contained 0.6mL NMP were determined at 37 °C, respectively. The electrical conductivity of PBS solution was linearly proportional to the amount of NMP. Organogel contained 0.6 mL NMP in PBS solution showed a descending of electrical conductivity as time runs, while the value of electrical conductivity was almost a constant at 7.58 ms/cm after 110 min, which was nearly equaled to the electrical conductivity of 0.6 mL NMP in PBS solution (7.59 ms/cm). This data indicated that the diffusion of NMP caused the descending of system electrical conductivity and NMP completely diffused from organogel after 110 min, which led to the constant electrical conductivity. Meanwhile, photographs of organogel showed that the gel formed from periphery to center gradually, and totally formed after 110 min. The diffusion terminal point of NMP from organogel could be perfectly anticipated and controlled by this method. Consequently, this electrochemical method had visually simulated the gelling process and located gelling time of organogel in medium solution by measuring variation of electrical conductivity. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Rapid injection of rocuronium reduces withdrawal movement on injection.

    PubMed

    Lee, Yong Cheol; Jang, Young Ho; Kim, Jin Mo; Lee, Sang Gyu

    2009-09-01

    To test whether rapid injection of rocuronium reduces withdrawal movement on injection. Randomized, prospective trial. Operating room in a university hospital. 150 ASA physical status I and II patients aged 18 to 60 years, undergoing general anesthesia. Patients were randomized to three groups. After undergoing anesthesia induction with thiopental sodium, then 5 seconds later receiving a rubber tourniquet applied to the mid-forearm to stop intravenous (IV) flow by gravity, the pretreatment drug was injected. The tourniquet was held for 15 seconds then released, and 1.0 mg/kg of 1% rocuronium was injected IV. Group C patients (n = 50) were pretreated with 0.1 mL/kg of 0.9% NaCl and then injected with rocuronium slowly within 10 seconds. Group L patients (n = 50) were pretreated with 0.1 mL/kg of preservative-free 1% lidocaine and then injected with rocuronium slowly within 10 seconds. Group R patients (n = 50) were pretreated with 0.1 mL/kg of 0.9% NaCl and then rapidly injected with rocuronium within approximately one second (as quickly as possible). After injection of the patient with the study drug, a single anesthesiologist with no knowledge of the study protocol graded each patient's response as follows: 0 = no response; 1 = mild movement limited to the wrist only; 2 = moderate movement involving the elbow and shoulder; and 3 = severe movement involving more than one extremity. Group C had the most intense and frequent withdrawal response. The frequency and intensity of withdrawal movement was significantly less in Groups L and R than Group C. No significant difference in withdrawal response between Groups L and R was noted. Withdrawal response can be significantly reduced for rocuronium injection without lidocaine pretreatment, simply through rapid injection.

  9. Rapid sample injection for hyperpolarized NMR spectroscopy.

    PubMed

    Bowen, Sean; Hilty, Christian

    2010-06-14

    Due to its ability to enhance the signal of a single NMR scan by several orders of magnitude, solid-to-liquid state dynamic nuclear polarization (DNP) appears well suited for the analysis of minimal amounts of compounds, as well as for the study of rapid chemical reactions. A key requirement in enabling the application of DNP-NMR to typical small-molecule substances encountered in chemistry and biochemistry is the ability to obtain high-resolution spectra, while at the same time minimizing the loss of polarization due to spin relaxation between the separate steps of DNP polarization and NMR measurement. Here, we present data demonstrating the capability of measuring DNP enhanced NMR spectra of compounds with comparably short relaxation times, with only minimal line broadening attributable to the sample transfer process. We discuss the performance characteristics of a sample injection apparatus specifically designed to provide high-resolution DNP-NMR spectra of small molecule compounds.

  10. Cure Studies and Cured Properties of Diglycidyl Ether of 4- Methylolresorcinol (A Rapid-Gelling Epoxy Resin)

    DTIC Science & Technology

    1977-05-01

    potassium iodide method. A resin sample of were determined by the 1.0 to 1.5 g was weighed Erlenmeyer flask, mixture was then To the held at...bromophenol blue in 99.9 g n-propanol) and 3.0 g of potassium iodide in 5 ml of distilled water were added rapidly. The titrated with 1 N...increase its shelf life , the resin should therefore be stored at lower temperatures. At -14"C ាF), no viscosity increase was noticed over 6 months

  11. Injectable and rapid-setting calcium phosphate bone cement with dicalcium phosphate dihydrate.

    PubMed

    Burguera, Elena F; Xu, Hockin H K; Weir, Michael D

    2006-04-01

    Calcium phosphate cement (CPC) sets in situ with intimate adaptation to the contours of defect surfaces, and forms an implant having a structure and composition similar to hydroxyapatite, the putative mineral in teeth and bones. The objective of the present study was to develop an injectable CPC using dicalcium phosphate dihydrate (DCPD) with a high solubility for rapid setting. Two agents were incorporated to impart injectability and fast-hardening to the cement: a hardening accelerator (sodium phosphate) and a gelling agent (hydroxypropyl methylcellulose, HPMC). The cement with DCPD was designated as CPC(D), and the conventional cement was referred to as CPC(A). Using water without sodium phosphate, CPC(A) had a setting time of 82 +/- 6 min. In contrast, CPC(D) exhibited rapid setting with a time of 17 +/- 1 min. At 0.2 mol/L sodium phosphate, setting time for CPC(D) was 15 +/- 1 min, significantly faster than 40 +/- 2 min for CPC(A) (Tukey's at 0.95). Sodium phosphate decreased the paste injectability (measured as the paste mass extruded from the syringe divided by the original paste mass inside the syringe). However, the addition of HPMC dramatically increased the paste injectability. For CPC(D), the injectability was increased from 65% +/- 12% without HPMC to 98% +/- 1% with 1% HPMC. Injectability of CPC(A) was also doubled to 99% +/- 1%. The injectable and rapid-setting CPC(D) possessed flexural strength and elastic modulus values overlapping the reported values for sintered porous hydroxyapatite implants and cancellous bone. In summary, the rapid setting and relatively high strength and elastic modulus of CPC(D) should help the graft to quickly attain strength and geometrical integrity within a short period of time postoperatively. Furthermore, the injectability of CPC(D) may have potential for procedures involving defects with limited accessibility or narrow cavities, when there is a need for precise placement of the paste, and when using minimally invasive

  12. Rapid assessment of injection practices in Cambodia, 2002

    PubMed Central

    Vong, Sirenda; Perz, Joseph F; Sok, Srun; Som, Seiharath; Goldstein, Susan; Hutin, Yvan; Tulloch, James

    2005-01-01

    Background Injection overuse and unsafe injection practices facilitate transmission of bloodborne pathogens such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Anecdotal reports of unsafe and unnecessary therapeutic injections and the high prevalence of HBV (8.0%), HCV (6.5%), and HIV (2.6%) infection in Cambodia have raised concern over injection safety. To estimate the magnitude and patterns of such practices, a rapid assessment of injection practices was conducted. Methods We surveyed a random sample of the general population in Takeo Province and convenience samples of prescribers and injection providers in Takeo Province and Phnom Penh city regarding injection-related knowledge, attitudes, and practices. Injection providers were observed administering injections. Data were collected using standardized methods adapted from the World Health Organization safe injection assessment guidelines. Results Among the general population sample (n = 500), the overall injection rate was 5.9 injections per person-year, with 40% of participants reporting receipt of ≥ 1 injection during the previous 6 months. Therapeutic injections, intravenous infusions, and immunizations accounted for 74%, 16% and 10% of injections, respectively. The majority (>85%) of injections were received in the private sector. All participants who recalled their last injection reported the injection was administered with a newly opened disposable syringe and needle. Prescribers (n = 60) reported that 47% of the total prescriptions they wrote included a therapeutic injection or infusion. Among injection providers (n = 60), 58% recapped the syringe after use and 13% did not dispose of the used needle and syringe appropriately. Over half (53%) of the providers reported a needlestick injury during the previous 12 months. Ninety percent of prescribers and injection providers were aware HBV, HCV, and HIV were transmitted through unsafe injection practices

  13. Nanotechnology Investigated for Future Gelled and Metallized Gelled Fuels

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    2003-01-01

    The objective of this research is to create combustion data for gelled and metallized gelled fuels using unique nanometer-sized gellant particles and/or nanometer-sized aluminum particles. Researchers at the NASA Glenn Research Center are formulating the fuels for both gas turbine and pulsed detonation engines. We intend to demonstrate metallized gelled fuel ignition characteristics for pulse detonation engines with JP/aluminum fuel and for gas turbine engines with gelled JP, propane, and methane fuel. The fuels to be created are revolutionary as they will deliver the highest theoretically maximum performance of gelled and metallized gelled fuels. Past combustion work has used micrometer-sized particles, which have limited the combustion performance of gelled and metallized gelled fuels. The new fuel used nanometer-sized aluminum oxide particles, which reduce the losses due to mismatch in the gas and solid phases in the exhaust. Gelled fuels provide higher density, added safety, reduced fuel slosh, reduced leakage, and increased exhaust velocity. Altogether, these benefits reduce the overall size and mass of the vehicle, increasing its flexibility.

  14. Rapid Self-Integrating, Injectable Hydrogel for Tissue Complex Regeneration.

    PubMed

    Hou, Sen; Wang, Xuefei; Park, Sean; Jin, Xiaobing; Ma, Peter X

    2015-07-15

    A novel rapid self-integrating, injectable, and bioerodible hydrogel is developed for bone-cartilage tissue complex regeneration. The hydrogels are able to self-integrate to form various structures, as can be seen after dying some hydrogel disks pink with rodamine. This hydrogel is demonstrated to engineer cartilage-bone complex.

  15. Break-up characteristics of gelled propellant simulants with various gelling agent contents

    NASA Astrophysics Data System (ADS)

    Lee, Inchul; Koo, Jaye

    2010-12-01

    Gel propulsion systems have many advantages with respect to high performance, the energy management of liquid propulsion systems, storability, high density impulse, and low leakage of liquid propellants. The atomization process provides sufficient contact surface area between the gelled fuel and oxidizer jets. It is important to study how injection characteristics of gelled propellants are related with break-up and spray distribution. The break-up and mixing processes are very important in achieving maximum efficiency and necessitate the careful study of combustion instability. Gelled propellants are non-Newtonian fluids in which the viscosity is a function of the shear rate, and they have a high dynamic shear viscosity which depends on the amount of gelling agent contents. The present study has focused on the break-up process, wave development of ligament and liquid sheets formed by impinging jets with various gelling agent contents. Especially, the break-up processes of the impinging jets at the initial conditions are studied. The break-up process of like-on-like doublet impinging jets are experimentally characterized using non-Newtonian liquids which are mixed by ionized water 98.5 wt%, Carbopol 941 0.5wt% or 1.0wt%, and NaOH(concentration 10%) 1.0wt%. For the like-on-like doublet injector, the generation of a liquid sheet at the impinging point of two jets was observed. The spray shape with elliptical pattern is distributed in a perpendicular direction to the momentum vectors of the jets. Gelled propellant simulants with high viscosity jets are more stable and produce less pronounced surface waves than low viscosity jets. Generally, the break-up length decreased due to the increasing Reynolds number. However, surface waves and atomized droplets increased. Gelled propellant simulants from like-on-like doublet impinging jets have the spray shape of closed rim patterns at low pressure. Also, the rim patterns of spray have no disturbances on the spray sheet. As the

  16. Rapid self-integrating, injectable hydrogel for tissue complex regeneration

    PubMed Central

    Hou, Sen; Wang, Xuefei; Park, Sean; Jin, Xiaobing

    2015-01-01

    A novel rapid self-integrating, injectable, and bio-erodible hydrogel is developed for tissue complex regeneration. The figure shows the self-integration of the hydrogel pieces to form various structures. In the figure, some hydrogel disks were dyed pink with rodamine and the others were left with the original light yellow color to visualize the interfaces (scale bar=5mm). This hydrogel is demonstrated to engineer cartilage-bone complex. PMID:25946414

  17. Gelled compositions and well treating

    SciTech Connect

    Swanson, B.L.

    1984-04-03

    Gelled compositions suitable as fracture fluids and water diversion agents comprising water, a polymeric viscosifier, an aldehyde component, and at least one phenolic component such as resorcinol, catechol, and the like, as well as selected oxidized phenolic materials such as 1,4-benzoquinone of natural or synthetic origin and natural and modified tannins. The gelled compositions can additionally contain gel stabilizers and chemical buffering agents.

  18. Novel injectable, self-gelling hydrogel-microparticle composites for bone regeneration consisting of gellan gum and calcium and magnesium carbonate microparticles.

    PubMed

    Douglas, Timothy E L; Łapa, Agata; Reczyńska, Katarzyna; Krok-Borkowicz, Małgorzata; Pietryga, Krzysztof; Samal, Sangram Keshari; Declercq, Heidi A; Schaubroeck, David; Boone, Marijn; Van der Voort, Pascal; De Schamphelaere, Karel; Stevens, Christian V; Bliznuk, Vitaliy; Balcaen, Lieve; Parakhonskiy, Bogdan V; Vanhaecke, Frank; Cnudde, Veerle; Pamuła, Elżbieta; Skirtach, Andre G

    2016-11-21

    The suitability of hydrogel biomaterials for bone regeneration can be improved by incorporation of an inorganic phase in particle form, thus maintaining hydrogel injectability. In this study, carbonate microparticles containing different amounts of calcium (Ca) and magnesium (Mg) were added to solutions of the anionic polysaccharide gellan gum (GG) to crosslink GG by release of Ca(2+) and Mg(2+) from microparticles and thereby induce formation of hydrogel-microparticle composites. It was hypothesized that increasing Mg content of microparticles would promote GG hydrogel formation. The effect of Mg incorporation on cytocompatibility and cell growth was also studied. Microparticles were formed by mixing Ca(2+) and Mg(2+) and [Formula: see text] ions in varying concentrations. Microparticles were characterized physiochemically and subsequently mixed with GG solution to form hydrogel-microparticle composites. The elemental Ca:Mg ratio in the mineral formed was similar to the Ca:Mg ratio of the ions added. In the absence of Mg, vaterite was formed. At low Mg content, magnesian calcite was formed. Increasing the Mg content further caused formation of amorphous mineral. Microparticles of vaterite and magnesium calcite did not induce GG hydrogel formation, but addition of Mg-richer amorphous microparticles induced gelation within 20 min. Microparticles were dispersed homogeneously in hydrogels. MG-63 osteoblast-like cells were cultured in eluate from hydrogel-microparticle composites and on the composites themselves. All composites were cytocompatible. Cell growth was highest on composites containing particles with an equimolar Ca:Mg ratio. In summary, carbonate microparticles containing a sufficient amount of Mg induced GG hydrogel formation, resulting in injectable, cytocompatible hydrogel-microparticle composites.

  19. Gelled MMH hypergolic droplet investigation

    NASA Astrophysics Data System (ADS)

    Solomon, Yair

    Gelled propellants are promising candidates for certain future rocket applications, offering potential improvements in performance and/or safety over conventional liquid and solid systems. In particular, gelled hypergolic propellants can eliminate some handling difficulties by reducing leakage hazard. Before such systems can be developed, however, a fundamental understanding of combustion of the gel droplet is required. This study addresses the combustion behavior of monomethyl hydrazine (MMH) droplet gelled with both hydroxypropyl cellulose (HPC) and fumed silica in an environment of gaseous nitrogen dioxide. All MMH/HPC gel droplets displayed swelling and jetting that are typical to hydrocarbon gels with an organic gelling agent. Burning rates were measured for droplet diameters from 1.8 to 3.2 mm at three ambient pressures of 1.72, 2.06 and 2.89 bar. It was found that the droplet burning rate is dependent on the droplet diameter similarly to liquid MMH. Over the investigated pressure range, no dependence of burning rate on pressure was found. The combustion of MMH/HPC gel was compared to MMH/tetraglyme to examine the influence the type of gelling agent. Droplets of MMH and liquid tetraglyme showed increasing swelling frequencies and volume fluctuations during combustion while the MMH and HPC droplets exhibited a more constant burning history. The MMH/Silica gels showed a different combustion mechanism with the formation of a rigid silica structure, micro-explosions, and up to a 50% reduction in droplet volume during combustion.

  20. Rapid prototyping polymers for microfluidic devices and high pressure injections.

    PubMed

    Sollier, Elodie; Murray, Coleman; Maoddi, Pietro; Di Carlo, Dino

    2011-11-21

    Multiple methods of fabrication exist for microfluidic devices, with different advantages depending on the end goal of industrial mass production or rapid prototyping for the research laboratory. Polydimethylsiloxane (PDMS) has been the mainstay for rapid prototyping in the academic microfluidics community, because of its low cost, robustness and straightforward fabrication, which are particularly advantageous in the exploratory stages of research. However, despite its many advantages and its broad use in academic laboratories, its low elastic modulus becomes a significant issue for high pressure operation as it leads to a large alteration of channel geometry. Among other consequences, such deformation makes it difficult to accurately predict the flow rates in complex microfluidic networks, change flow speed quickly for applications in stop-flow lithography, or to have predictable inertial focusing positions for cytometry applications where an accurate alignment of the optical system is critical. Recently, other polymers have been identified as complementary to PDMS, with similar fabrication procedures being characteristic of rapid prototyping but with higher rigidity and better resistance to solvents; Thermoset Polyester (TPE), Polyurethane Methacrylate (PUMA) and Norland Adhesive 81 (NOA81). In this review, we assess these different polymer alternatives to PDMS for rapid prototyping, especially in view of high pressure injections with the specific example of inertial flow conditions. These materials are compared to PDMS, for which magnitudes of deformation and dynamic characteristics are also characterized. We provide a complete and systematic analysis of these materials with side-by-side experiments conducted in our lab that also evaluate other properties, such as biocompatibility, solvent compatibility, and ease of fabrication. We emphasize that these polymer alternatives, TPE, PUMA and NOA, have some considerable strengths for rapid prototyping when bond

  1. Gelled Anti-icing Agents

    NASA Technical Reports Server (NTRS)

    Markles, O. F.; Sperber, H. H.

    1983-01-01

    Pectin added to antifreeze/water mixture. Formulations include water with dimethyl sulfoxide (DMSO) as deicer and pectin as gel former. Without gelling agent, deicer runs off vertical surfaces. Without pectin solution will completely evaporate in far less time. Agents developed have wide potential for ice prevention on runways, highways, bridges and sidewalks.

  2. Gelled Anti-icing Agents

    NASA Technical Reports Server (NTRS)

    Markles, O. F.; Sperber, H. H.

    1983-01-01

    Pectin added to antifreeze/water mixture. Formulations include water with dimethyl sulfoxide (DMSO) as deicer and pectin as gel former. Without gelling agent, deicer runs off vertical surfaces. Without pectin solution will completely evaporate in far less time. Agents developed have wide potential for ice prevention on runways, highways, bridges and sidewalks.

  3. Gelled Electrolytes For Lithium Batteries

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesan; Attia, Alan; Halpert, Gerald

    1993-01-01

    Gelled polymer electrolyte consists of polyacrylonitrile (PAN), LiBF4, and propylene carbonate (PC). Thin films of electrolyte found to exhibit stable bulk conductivities of order of 10 to the negative 3rd power S/cm at room temperature. Used in thinfilm rechargeable lithium batteries having energy densities near 150 W h/kg.

  4. A microbial trigger for gelled polymers

    SciTech Connect

    Bailey, S.; Bryant, R.; Zhu, T.

    1995-12-31

    A process using a microbially gelled biopolymer was developed and used to modify permeability in coreflood experiments. Alkaline-soluble curdlan biopolymer was mixed with microbial nutrients and acid-producing alkaliphilic bacteria, and injected into Berea sandstone cores. Concurrent bottle tests with the polymer solution were incubated beside the core. Polymer in the bottle tests formed rigid gel in 2-5 days at 27{degree}C. After 7 days incubation, 25-35 psi fluid pressure was required to begin flow through the cores. Permeability of the cores was decreased from 852 md to 2.99 md and from 904 md to 4.86 md, respectively, giving residual resistance factors of 334 and 186.

  5. Murray Gell-Mann -- a Scientific Biography

    NASA Astrophysics Data System (ADS)

    Fritzsch, Harald

    2011-11-01

    Murray Gell-Mann is one of the most outstanding scientists of the last century. At this conference on the occasion of his 80th birthday, the important scientific achievements of Gell-Mann will be discussed. I shall describe in particular his contributions to particle physics. Murray's father Arthur Gell-Mann grew up in Czernowitz, a city once belongs to the Austrian empire. Today, Czernowitz belongs to the Ukraine. Arthur Gell-Mann studied in Vienna and came to the United States in 1911. He lived and worked in New York, where he became the owner of a language school and married Pauline Reichstein...

  6. Rapidly progressive lumbar subdural empyema following acromial bursal injection.

    PubMed

    Coumans, Jean-Valery C E; Walcott, Brian P

    2011-11-01

    Spinal subdural empyemas are rare. We describe a 53-year-old male who presented with back pain, mental status changes, and sepsis. Five days prior he had undergone a triamcinolone and lidocaine injection of the acromial bursa. He also had a remote history of epidural steroid injection for thoracic back pain. Two lumbar MRI conducted 62 hours apart revealed a newly developed subdural empyema that was successfully treated with surgical evacuation and post-operative antibiotics.

  7. Pressure dispensable gelled alcohol fuel

    SciTech Connect

    Monick, J.A.

    1982-12-28

    A pressurized fuel gel composition particularly suitable for igniting wood and charcoal consisting essentially of, by weight, 42-90% of at least one c1-c6 monohydric alcohol, 0.5-6% of water-soluble gelling agent, up to about 24% water and a correlated amount of propellant from 0.5% to 30% characterized by a gel structure which forms a shape retaining mass upon contact with wood or charcoal that is maintained during the burning of said composition. Also within the scope of the invention is an aerosol product comprising said pressurized composition enclosed within a pressure-tight container having valve means for expelling the composition.

  8. Rapid clinical diagnostics assays using injection-molded planar waveguides

    NASA Astrophysics Data System (ADS)

    Herron, James N.; Wang, Hsu-Kun; Terry, Allen H.; Durtschi, Jacob D.; Tan, Lyndon; Astill, Mark E.; Smith, Richard S.; Christensen, Douglas A.

    1998-04-01

    The goal of our research program is to develop an evanescent wave immunoassay system that can be used in point-of-care and critical care settings. Several key attributes are required to accomplish this goal: (1) the assay system should be at least as sensitive as present day immunoassays; (2) assay time should be 5 minutes or less; (3) the assay protocol should be relatively simple; (4) the sensor should be capable of performing more than one assay on a single specimen; (5) the assay system should be able to accommodate specimens such as serum, plasma and whole blood; and (6) the sensor should be an inexpensive, disposable cartridge. Our laboratory has developed an injection-molded planar waveguide sensor that meets most, if not all, of these attributes. This sensor has been evaluated in a number of different immunoassays for analytes such as bovine serum albumin, human chorionic gonadotrophin, creatine phosphokinase MB and cardiac troponin I.

  9. The dual temperature/pH-sensitive multiphase behavior of poly(N-isopropylacrylamide-co-acrylic acid) microgels for potential application in in situ gelling system.

    PubMed

    Xiong, Wei; Gao, Xiang; Zhao, Yanbing; Xu, Huibi; Yang, Xiangliang

    2011-05-01

    Poly(N-isopropylacrylamide-co-acrylic acid) microgels (PNA) may be an excellent formulation for in situ gelling system due to their high sensitivity and fast response rate. Four monodispersed PNA microgels with various contents of acrylic acid (AA) were synthesized by emulsion polymerization in this paper. Their hydrodynamic diameters decreased reversibly with both decreasing pH and increasing temperature. The dual temperature/pH-sensitivity was influenced by many factors such as AA content, cross-link density and ion strength. In addition, high concentration PNA dispersions underwent multiple phase transition according to different temperatures, pHs and concentrations, which were summarized in a 3D sol-gel phase diagram in this study. According to the sol-gel phase transition, 8% PNA-025 dispersion maintained a relatively low viscosity and favorable fluidity at pH 5.0 in the temperature range of 25-40°C, but it rapidly increased in viscosity at pH 7.4 and gelled at 37°C. This feature enabled the dual temperature/pH-sensitive microgels to overcome the troubles in syringing of temperature sensitive materials during the injection. Apart from this, PNA could form gel well in in vitro (e.g., medium and serum) and in in vivo with low cytotoxicity. Therefore, it is promising for PNA to be applied in the in situ gelling system.

  10. Rapid control of mold temperature during injection molding process

    SciTech Connect

    Liparoti, Sara; Titomanlio, Giuseppe; Hunag, Tsang Min; Cakmak, Mukerrem; Sorrentino, Andrea

    2015-05-22

    The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

  11. Food gels: gelling process and new applications.

    PubMed

    Banerjee, Soumya; Bhattacharya, Suvendu

    2012-01-01

    Food gels are viscoelastic substances and several gelled products are manufactured throughout the world. The gelling agents in foods are usually polysaccharides and proteins. In food gels, the polymer molecules are not cross-linked by covalent bonds with the exception of disulphide bonds in some protein gels. Instead, the molecules are held together by a combination of weak inter-molecular forces like hydrogen bonds, electrostatic forces, Van der Waals forces, and hydrophobic interactions. Polysaccharides including hydrocolloids are strongly hydrated in aqueous medium but they tend to have less ordered structures. The mechanism of gelation depends on the nature of the gelling agent(s) and on the conditions of gel formation like the temperature, the presence of ions, the pH, and the concentration of gelling agents, etc. Characterization of gels can be performed in several ways of which rheological measurements are frequently practiced. Multi-component or mixed gel system is an important area of interest in which two or more gelling components are simultaneously used to achieve certain specific structural and functional characteristics. We here discuss about the different gels and gelling agents, the characterization of gels, and the mechanism of gelation with an emphasis on mixed or multi-component gels that would have significant commercial applications.

  12. Rivastigmine-loaded in situ gelling nanostructured lipid carriers for nose to brain delivery.

    PubMed

    Wavikar, Preeti R; Vavia, Pradeep R

    2015-01-01

    In the current research work, rivastigmine (RV)-loaded in situ gelling nanostructured lipid carriers (NLCs) were developed for nose to brain delivery. NLCs were fabricated by ethanol injection method using glyceryl monosterate, Capmul MCM C8, Lecithin and Tween 80. NLCs showed average particle size of 123.2 ± 2.3 nm with entrapment efficiency of 68.34 ± 3.4%. DSC, XRD and IR studies showed complete amorphization and incorporation of the drug into nanoparticles. NLCs were incorporated into an in situ gelling system using 0.8% gellan gum and 15% Lutrol F 127. RV in situ gel showed excellent elasticity, rheology, mucoadhesion and adhesiveness to facilitate its adhesion to the upper nasal mucosa. NLC-based in situ gel showed a 2-fold increase in nasal permeation of the drug over plain RV solution. In situ gelling NLCs showed a 3-fold increase in enzyme inhibition efficacy.

  13. Apparatus and method for gelling liquefied gasses

    NASA Technical Reports Server (NTRS)

    Elliott, Adam (Inventor); DiSalvo, Roberto (Inventor); Shepherd, Phillip (Inventor); Kosier, Ryan (Inventor)

    2010-01-01

    The present invention is a method and apparatus for gelling liquid propane and other liquefied gasses. The apparatus includes a temperature controlled churn mixer, vacuum pump, liquefied gas transfer tank, and means for measuring amount of material entering the mixer. The method uses gelling agents such as silicon dioxide, clay, carbon, or organic or inorganic polymers, as well as dopants such as titanium, aluminum, and boron powders. The apparatus and method are particularly useful for the production of high quality rocket fuels and propellants.

  14. Modular Injectable Matrices Based on Alginate Solution/Microsphere Mixtures That Gel in situ and Co-Deliver Immunomodulatory Factors

    PubMed Central

    Hori, Yuki; Winans, Amy M.; Irvine, Darrell J.

    2011-01-01

    Biocompatible polymer solutions that can crosslink in situ following injection to form stable hydrogels are of interest as depots for sustained delivery of therapeutic factors or cells, and as scaffolds for regenerative medicine. Here, injectable self-gelling alginate formulations obtained by mixing alginate microspheres (as calcium reservoirs) with soluble alginate solutions were characterized for potential use in immunotherapy. Rapid redistribution of calcium ions from microspheres into the surrounding alginate solution led to rapid crosslinking and formation of stable hydrogels. The mechanical properties of the resulting gels correlated with the concentration of calcium reservoir microspheres added to the solution. Soluble factors such as the cytokine interleukin-2 were readily incorporated into self-gelling alginate matrices by simply mixing them with the formulation prior to gelation. Using alginate microspheres as modular components, strategies for binding immunostimulatory CpG oligonucleotides onto the surface of microspheres were also demonstrated. When injected subcutaneously in the flanks of mice, self-gelling alginate formed soft macroporous gels supporting cellular infiltration and allowing ready access to microspheres carrying therapeutic factors embedded in the matrix. This in-situ gelling formulation may thus be useful for stimulating immune cells at a desired locale such as solid tumors or infection sites as well as for other soft tissue regeneration applications. PMID:19117820

  15. Apparatus and method for gelling liquefied gasses

    NASA Technical Reports Server (NTRS)

    Elliott, Adam (Inventor); DiSalvo, Roberto (Inventor); Shepherd, Phillip (Inventor); Kosier, Ryan (Inventor)

    2011-01-01

    A method and apparatus for gelling liquid propane and other liquefied gasses includes a temperature controlled churn mixer, vacuum pump, liquefied gas transfer tank, and means for measuring amount of material entering the mixer. The apparatus and method are particularly useful for the production of high quality rocket fuels and propellants.

  16. Ca:Mg:Zn:CO3 and Ca:Mg:CO3-tri- and bi-elemental carbonate microparticles for novel injectable self-gelling hydrogel-microparticle composites for tissue regeneration.

    PubMed

    Douglas, Timothy E L; Sobczyk, Katarzyna; Łapa, Agata; Włodarczyk, Katarzyna; Brackman, Gilles; Vidiasheva, Irina; Reczyńska, Katarzyna; Pietryga, Krzysztof; Schaubroeck, David; Bliznuk, Vitaliy; Voort, Pascal Van Der; Declercq, Heidi A; Bulcke, Jan Van den; Samal, Sangram Keshari; Khalenkow, Dmitry; Parakhonskiy, Bogdan V; Van Acker, Joris; Coenye, Tom; Lewandowska-Szumieł, Małgorzata; Pamuła, Elżbieta; Skirtach, Andre G

    2017-03-24

    Injectable composites for tissue regeneration can be developed by dispersion of inorganic microparticles and cells in a hydrogel phase. In this study, multifunctional carbonate microparticles containing different amounts of calcium, magnesium and zinc were mixed with solutions of gellan gum (GG), an anionic polysaccharide, to form injectable hydrogel-microparticle composites, containing Zn, Ca and Mg. Zn and Ca were incorporated into microparticle preparations to a greater extent than Mg. Microparticle groups were heterogeneous and contained microparticles of differing shape and elemental composition. Zn-rich microparticles were 'star shaped' and appeared to consist of small crystallites, while Zn-poor, Ca- and Mg-rich microparticles were irregular in shape and appeared to contain lager crystallites. Zn-free microparticle groups exhibited the best cytocompatibility and, unexpectedly, Zn-free composites showed the highest antibacterial activity towards methicilin-resistant Staphylococcus aureus. Composites containing Zn-free microparticles were cytocompatible and therefore appear most suitable for applications as an injectable biomaterial. This study proves the principle of creating bi- and tri-elemental microparticles to induce the gelation of GG to create injectable hydrogel-microparticle composites.

  17. A non-comparative evaluation of a chitosan gelling fibre.

    PubMed

    Orig, Rommel; Singleton, Joseph

    An evaluation of chitosan gelling fibre dressing (KytoCel, Aspen Medical) was undertaken by tissue viability nurses in a large acute trust from December 2014--May 2015. The aim of this evaluation was to examine whether the gelling-fibre dressing can improve healing outcomes--reduction of bioburden and promotion of wound healing in both acute and chronic wounds that are infected or critically colonised. A total of 20 patients were recruited with acute and other complex wounds where wound infection was already established, or an excessive wound bioburden was delaying healing. Wound swabs were taken before and after dressing application between days 1, 3, 5 and 11 when clinically indicated, or at the surgical and medical teams' request. No more than two sets of swabs were taken in all patients. The evaluation incorporated three main criteria: patient baseline data, dressing performance, and patient perspective. Key findings were a significant reduction in wound size; rapid improvement of the quality of granulation tissue in 11 patients (55%), the reduction of the wound bioburden, and malodour combined with effective exudate management. The investigators also wanted to establish if there was a significant reduction in the identified bacteria from the initial wound swab results. Some patients were on systemic antibiotic therapy, their reduction in bacteria species may also be related to secondary dressings used. More robust investigation may be required to establish if the bacterial reduction was a result of the primary dressing.

  18. Flow visualization of a rocket injector spray using gelled propellant simulants

    NASA Technical Reports Server (NTRS)

    Green, James M.; Rapp, Douglas C.; Roncace, James

    1991-01-01

    A study was conducted at NASA-Lewis to compare the atomization characteristics of gelled and nongelled propellant simulants. A gelled propellant simulant composed of water, sodium hydroxide, and an acrylic acid polymer resin (as the gelling agent) was used to simulate the viscosity of an aluminum/PR-1 metallized fuel gel. Water was used as a comparison fluid to isolate the rheological effects of the water-gel and to simulate nongelled RP-1. The water-gel was injected through the central orifice of a triplet injector element and the central post of a coaxial injector element. Nitrogen gas flowed through the outer orifices of the triplet injector element and through the annulus of the coaxial injector element and atomized the gelled and nongelled liquids. Photographs of the water-gel spray patterns at different operating conditions were compared with images obtained using water and nitrogen. A laser light was used for illumination of the sprays. The results of the testing showed that the water sprays produced a finer and more uniform atomization than the water-gel sprays. Rheological analysis of the water-gel showed poor atomization caused by high viscosity of water-gel delaying the transition to turbulence.

  19. Metallized Gelled Propellant Heat Transfer Tests Analyzed

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    1997-01-01

    A series of rocket engine heat transfer experiments using metallized gelled liquid propellants was conducted at the NASA Lewis Research Center. These experiments used a small 20- to 40-lbf thrust engine composed of a modular injector, an igniter, a chamber, and a nozzle. The fuels used were traditional liquid RP-1 and gelled RP-1 with 0-, 5-, and 55-wt % loadings of aluminum particles. Gaseous oxygen was used as the oxidizer. Heat transfer measurements were made with a rocket engine calorimeter chamber and nozzle with a total of 31 cooling channels. Each channel used water flow to carry heat away from the chamber and the attached thermocouples; flow meters allowed heat flux estimates at each of the 31 stations.

  20. Rapid vascular escape of arterially injected 16alpha-radioiodo, 17beta-estradiol

    SciTech Connect

    Scharl, A.; Holt, J.A. )

    1993-03-20

    The authors undertook this study because confirmation of a rapid vascular escape and slow release back into the circulatory system suggests that arterial injection of radiohalogenated steroid receptor ligands might provide an efficacious route of administration for imaging or treatment of receptor-rich malignant tumors in peripheral tissues. The authors injected radiolabeled 16alpha-iodo, 17beta-estradiol ([I]-E) into the femoral artery of swine in a solution that contained [[sup 125]I]-E in a known ratio to [[sup 99]Tc]-labeled red blood cells. Fractions of femoral venous blood were collected at short intervals during 10 min. They looked for changes in the ratio of the radiolabeles. [[sup 99m]Tc]-labeled red blood cells are known to remain in the vascular system for an hour or more. After passage of the injectate through the capillary bed of the swine leg, a dramatic decrease of the initial [sup 125]I:[sup 99m]Tc ratio to only 10% was observed in the femoral venous blood. This ratio increased gradually during the next 10 min to approximately 30% of that in the injectate, indicating that a significant portion (approximately 90%) of the [[sup 125]I]-E was initially trapped in the limb and then slowly re-entered the vascular system. To obtain visual confirmation of the rapid vascular escape of iodo-estrogen, they injected either an imageable form of [I]-E ([[sup 123]I]-E) or [[sup 99m]Tc]-labeled red blood cells into the dorsal aorta of superovulated rabbits, whose smaller size allowed whole-body imaging. The biodistributions of these radiopharmaceuticals were surveyed continuously by real-time planar gamma imaging. A large fraction of [I]-E escapes from the vascular system during the first pass through an organ or limb, without regard to the estrogen receptor content of the tissue. 28 refs., 3 figs., 1 tab.

  1. Improving reservoir conformance using gelled polymer systems

    SciTech Connect

    Green, D.W.; Willhite, P.G.

    1992-12-25

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems -- an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by Cr(III) and an organic crosslinked system. Development of the KUSP1 system and evaluation and, identification of the organic crosslinked system will be conducted. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Progress report are presented for the following tasks: Development and selection of gelled polymer systems; physical and chemical characterization of gel systems; and mathematical modelling of gel systems.

  2. Improving reservoir conformance using gelled polymer systems

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1993-04-09

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems - an aqueous polysaccharide (KUSPI) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by CR(III) and an organic crosslinked system. Development of the KUSPI system and evaluation and identification of a suitable organic crosslinked system will be done. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Accomplishments for this period are presented for the following tasks: development and selection of gelled polymer systems, physical and chemical characterization of gel systems; and mathematical modeling of gel systems.

  3. Rapid and non-destructive identification of water-injected beef samples using multispectral imaging analysis.

    PubMed

    Liu, Jinxia; Cao, Yue; Wang, Qiu; Pan, Wenjuan; Ma, Fei; Liu, Changhong; Chen, Wei; Yang, Jianbo; Zheng, Lei

    2016-01-01

    Water-injected beef has aroused public concern as a major food-safety issue in meat products. In the study, the potential of multispectral imaging analysis in the visible and near-infrared (405-970 nm) regions was evaluated for identifying water-injected beef. A multispectral vision system was used to acquire images of beef injected with up to 21% content of water, and partial least squares regression (PLSR) algorithm was employed to establish prediction model, leading to quantitative estimations of actual water increase with a correlation coefficient (r) of 0.923. Subsequently, an optimized model was achieved by integrating spectral data with feature information extracted from ordinary RGB data, yielding better predictions (r = 0.946). Moreover, the prediction equation was transferred to each pixel within the images for visualizing the distribution of actual water increase. These results demonstrate the capability of multispectral imaging technology as a rapid and non-destructive tool for the identification of water-injected beef.

  4. Rapid startup in relativistic backward wave oscillator by injecting external backward signal

    SciTech Connect

    Song, W.; Teng, Y.; Zhang, Z. Q.; Li, J. W.; Sun, J.; Chen, C. H.; Zhang, L. J.

    2012-08-15

    Investigation on accelerating the building up of oscillation and achieving a rapid startup in powerful relativistic backward wave oscillator by injecting a weak external backward signal is carried out in this paper. Synchronizing the signal with the backward wave excited by intense electron beam extracting with slow wave structure, the initial noise is greatly reduced and mode competition is restrained. The analysis is demonstrated by high power X-band backward wave oscillator experiment, in which a plasma switch is designed to realize the backward signal injection. The results show that the significant reduction of microwave output delay is attained and the start time of oscillation is ahead of 10 ns with the energy conversion efficiency increases about 62%.

  5. Nanoparticulate gellants for metallized gelled liquid hydrogen with aluminum

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan; Starkovich, John; Adams, Scott

    1996-01-01

    Gelled liquid hydrogen was experimentally formulated using sol-gel technology. As a follow-on to work with cryogenic simulants, hydrogen was gelled with an alkoxide material: BTMSE. Initial results demonstrated that gellants with a specific surface area of 1000 m(exp 2)/g could be repeatably fabricated. Gelled hexane and metallized gelled hexane (with 13.8-wt% Al) were produced. Propellant settling testing was conducted for acceleration levels of 2 to 10 times normal gravity and a minimum gellant percentage was determined for stable gelled hexane and metalized gelled hexane. A cryogenic capillary rheometer was also designed, constructed, and used to determine the viscosity of gelled hydrogen. Small volumes of liquid hydrogen were gelled with a 7- to 8-wt% gellant level. The gelled H2 viscosity was 1.5 to 3.7 times that of liquid hydrogen: 0.048 to 0.116 mPa-s versus 0.03 mPa-s for liquid H2 (at 16 K and approximately 1 atm pressure).

  6. Environmental precursors to rapid light carbon injection at the Palaeocene/Eocene boundary.

    PubMed

    Sluijs, Appy; Brinkhuis, Henk; Schouten, Stefan; Bohaty, Steven M; John, Cédric M; Zachos, James C; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S; Crouch, Erica M; Dickens, Gerald R

    2007-12-20

    The start of the Palaeocene/Eocene thermal maximum--a period of exceptional global warming about 55 million years ago--is marked by a prominent negative carbon isotope excursion that reflects a massive input of 13C-depleted ('light') carbon to the ocean-atmosphere system. It is often assumed that this carbon injection initiated the rapid increase in global surface temperatures and environmental change that characterize the climate perturbation, but the exact sequence of events remains uncertain. Here we present chemical and biotic records of environmental change across the Palaeocene/Eocene boundary from two sediment sections in New Jersey that have high sediment accumulation rates. We show that the onsets of environmental change (as recorded by the abundant occurrence ('acme') of the dinoflagellate cyst Apectodinium) and of surface-ocean warming (as evidenced by the palaeothermometer TEX86) preceded the light carbon injection by several thousand years. The onset of the Apectodinium acme also precedes the carbon isotope excursion in sections from the southwest Pacific Ocean and the North Sea, indicating that the early onset of environmental change was not confined to the New Jersey shelf. The lag of approximately 3,000 years between the onset of warming in New Jersey shelf waters and the carbon isotope excursion is consistent with the hypothesis that bottom water warming caused the injection of 13C-depleted carbon by triggering the dissociation of submarine methane hydrates, but the cause of the early warming remains uncertain.

  7. Study of gelled LNG. Final technical report

    SciTech Connect

    Rudnicki, M I; Cabeal, J A; Hoffman, L C; Newton, R A; Schaplowsky, R K; Vander Wall, E M

    1980-01-01

    Research involved the characterization of gelled LNG (GELNG) with respect to process, flow, and use properties and an examination of the degree of safety enhancement attainable by gelation. The investigation included (1) an experimental examination of gel properties and gel safety characteristics as well as (2) an analytical study involving the economics and preliminary design of an industrial scale gelation system. The safety-related criterion for successful application of gelled LNG is the substantial reduction of the Maximum Distance to the Lower Flammability Limit, MDLFL. This will be achieved by first, gel-inhibition of the hydrodynamic pooling and spreading of the spill, and second, the suppressed thermal transport properties of the GELNG relative to those of LNG. The industrial scale gelation study evaluated a design capable of producing 11,000 gallons (LNG tank truck) of gel in two hours. The increased cost of gelation using this equipment was estimated at $0.23/10/sup 6/ Btu for plants with liquefaction facilities. The technical results of this study are supportive of the conclusion that gelation of LNG will reduce, relative to ungelled LNG, the hazard associated with a given size spill. Parameters of interest to the LNG facility operator (such as pumpability) are not significantly affected by gelation, and the impact on LNG delivery cost appears to be small, about 5%. Thus, the initial assumption that gelation would provide a practical means to enhance safety is supported by the results of this study. Larger scale, comparative spill tests of LNG and GELNG are now required to confirm the safety aspects of use of the gelled material.

  8. Gelled liquid oxygen/metal powder monopropellants

    NASA Technical Reports Server (NTRS)

    Wickman, John H.; James, Eric

    1992-01-01

    Al, Al-80/Mg-20 wt pct, Si, and Fe powders were mixed with LOX and gelled with 2-3 wt pct Cab-o-Sil to viscosities of 100 to 900 cps, at shear rates of up to 300/sec. These monopropellants were burned in a cylinder that was submerged in a liquid nitrogen bath. Ambient pressure data have shown that the monopropellants were extinguished when the flame front reached regions that had been submerged under the liquid nitrogen. Burning occurred in a pulsed fashion, and was most nearly steady in the case of the Al-Mg mixture. No sparking or energetic burning occurred in any of the cases tested.

  9. Development of in situ gelling and bio adhesive 5-Fluorouracil enema.

    PubMed

    Wang, Lu-Lu; Zheng, Wen-Sheng; Chen, Shao-Hua; Fang, Xia-Qin

    2013-01-01

    In this study, a novel 5-Fluorouracil (5-FU) enema with good bio adhesion and temperature sensitivity was developed using in situ gelling technology. The preparation was formulated as a free-flowing liquid before use, while a layer of gel film was quickly formed when administered in the rectum, with a large contact surface area. It also demonstrated good biocompatibility, appropriate gel strength and bio adhesive force with excellent adhesion to rectal mucosa and prolonged action time, allowing more effective drug absorption and diffusion to surrounding tissues. Poloxamer 407 and poloxamer 188 were applied to adjust the gelling temperature. With the addition of carbopol and polycarbophil (bio adhesive substances), the solubility of 5-FU and gel strength increased, the temperature of gelation and the surface area of drug contact on mucous epithelium decreased. Decreased adhesive force between the preparation and the mucous membrane of the rectum was demonstrated with improving carbopol and polycarbophil's concentration. In vitro release demonstrated that 5-FU in situ gelling enema with different bases had a rapid and almost complete drug release. We used an optimized formulation of P407/P188/polycarbophil/5-FU (17/2.5/0.2/1.0) for animal experiments. The result showed that the drug evenly covered the surface of the rectum and there was no leakage in 6 hours. The in situ gelling enema showed significantly higher rectal tissue levels of 5-FU compared with suppository and intravenous administration, indicating that 5-FU could be well absorbed due to the enlarged releasing area, longer retention time and larger amount of dissolved active ingredients. Systemically, 5-FU levels in the enema group were similar to those in the suppository group and significantly lower than the intravenous group. The enema was not associated with morphological damage to rectal tissue. These results suggest that the bio adhesive and in situ gelling enema could be a more effective rectal

  10. Development of In Situ Gelling and Bio Adhesive 5-Fluorouracil Enema

    PubMed Central

    Wang, Lu-Lu; Zheng, Wen-Sheng; Chen, Shao-Hua; Fang, Xia-Qin

    2013-01-01

    In this study, a novel 5-Fluorouracil (5-FU) enema with good bio adhesion and temperature sensitivity was developed using in situ gelling technology. The preparation was formulated as a free-flowing liquid before use, while a layer of gel film was quickly formed when administered in the rectum, with a large contact surface area. It also demonstrated good biocompatibility, appropriate gel strength and bio adhesive force with excellent adhesion to rectal mucosa and prolonged action time, allowing more effective drug absorption and diffusion to surrounding tissues. Poloxamer 407 and poloxamer 188 were applied to adjust the gelling temperature. With the addition of carbopol and polycarbophil (bio adhesive substances), the solubility of 5-FU and gel strength increased, the temperature of gelation and the surface area of drug contact on mucous epithelium decreased. Decreased adhesive force between the preparation and the mucous membrane of the rectum was demonstrated with improving carbopol and polycarbophil’s concentration. In vitro release demonstrated that 5-FU in situ gelling enema with different bases had a rapid and almost complete drug release. We used an optimized formulation of P407/P188/polycarbophil/5-FU (17/2.5/0.2/1.0) for animal experiments. The result showed that the drug evenly covered the surface of the rectum and there was no leakage in 6 hours. The in situ gelling enema showed significantly higher rectal tissue levels of 5-FU compared with suppository and intravenous administration, indicating that 5-FU could be well absorbed due to the enlarged releasing area, longer retention time and larger amount of dissolved active ingredients. Systemically, 5-FU levels in the enema group were similar to those in the suppository group and significantly lower than the intravenous group. The enema was not associated with morphological damage to rectal tissue. These results suggest that the bio adhesive and in situ gelling enema could be a more effective rectal

  11. Analysis of Ground-Water Flow in the Madison Aquifer using Fluorescent Dyes Injected in Spring Creek and Rapid Creek near Rapid City, South Dakota, 2003-04

    USGS Publications Warehouse

    Putnam, Larry D.; Long, Andrew J.

    2007-01-01

    The Madison aquifer, which contains fractures and solution openings in the Madison Limestone, is used extensively for water supplies for the city of Rapid City and other suburban communities in the Rapid City, S. Dak., area. The 48 square-mile study area includes the west-central and southwest parts of Rapid City and the outcrops of the Madison Limestone extending from south of Spring Creek to north of Rapid Creek. Recharge to the Madison Limestone occurs when streams lose flow as they cross the outcrop. The maximum net loss rate for Spring and Rapid Creek loss zones are 21 and 10 cubic feet per second (ft3/s), respectively. During 2003 and 2004, fluorescent dyes were injected in the Spring and Rapid Creek loss zones to estimate approximate locations of preferential flow paths in the Madison aquifer and to measure the response and transit times at wells and springs. Four injections of about 2 kilograms of fluorescein dye were made in the Spring Creek loss zone during 2003 (sites S1, S2, and S3) and 2004 (site S4). Injection at site S1 was made in streamflow just upstream from the loss zone over a 12-hour period when streamflow was about equal to the maximum loss rate. Injections at sites S2, S3, and S4 were made in specific swallow holes located in the Spring Creek loss zone. Injection at site R1 in 2004 of 3.5 kilograms of Rhodamine WT dye was made in streamflow just upstream from the Rapid Creek loss zone over about a 28-hour period. Selected combinations of 27 wells, 6 springs, and 3 stream sites were monitored with discrete samples following the injections. For injections at sites S1-S3, when Spring Creek streamflow was greater than or equal to 20 ft3/s, fluorescein was detected in samples from five wells that were located as much as about 2 miles from the loss zone. Time to first arrival (injection at site S1) ranged from less than 1 to less than 10 days. The maximum fluorescein concentration (injection at site S1) of 120 micrograms per liter (ug/L) at well CO

  12. Heather Gell and Music Education in the Community

    ERIC Educational Resources Information Center

    Nash, Sandra

    2014-01-01

    Kindergartener and Dalcroze teacher, Heather Gell (1896-1988), brought music to thousands of Australian children and adults. The community touched by Gell was vast: it included her classes in studios and teacher training colleges, "listeners in" to her radio programs, viewers of her television programs, Dalcroze trainees, and people in…

  13. Gelled Complex Fluids: Combining Unique Structures with Mechanical Stability.

    PubMed

    Stubenrauch, Cosima; Gießelmann, Frank

    2016-03-01

    Gelled complex fluids are soft materials in which the microstructure of the complex fluid is combined with the mechanical stability of a gel. To obtain a gelled complex fluid one either adds a gelator to a complex fluid or replaces the solvent in a gel by a complex fluid. The most prominent example of a "natural" gelled complex fluid is the cell. There are various strategies by which one can form a gelled complex fluid; one such strategy is orthogonal self-assembly, that is, the independent but simultaneous formation of two coexisting self-assembled structures within one system. The aim of this Review is to describe the structure and potential applications of various man-made gelled complex fluids and to clarify whether or not the respective system is formed by orthogonal self-assembly.

  14. Bienzymatic Biosensor for Rapid Detection of Aspartame by Flow Injection Analysis

    PubMed Central

    Radulescu, Maria-Cristina; Bucur, Bogdan; Bucur, Madalina-Petruta; Radu, Gabriel Lucian

    2014-01-01

    A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h−1 with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 μM for methanol and 0.2 μM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement. PMID:24412899

  15. Bienzymatic biosensor for rapid detection of aspartame by flow injection analysis.

    PubMed

    Radulescu, Maria-Cristina; Bucur, Bogdan; Bucur, Madalina-Petruta; Radu, Gabriel Lucian

    2014-01-09

    A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h⁻¹ with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 µM for methanol and 0.2 µM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement.

  16. Validated flow-injection method for rapid aluminium determination in anti-perspirants.

    PubMed

    López-Gonzálvez, A; Ruiz, M A; Barbas, C

    2008-09-29

    A flow-injection (FI) method for the rapid determination of aluminium in anti-perspirants has been developed. The method is based on the spectrophotometric detection at 535nm of the complex formed between Al ions and the chromogenic reagent eriochrome cyanine R. Both the batch and FI methods were validated by checking the parameters included in the ISO-3543-1 regulation. Variables involved in the FI method were optimized by using appropriate statistical tools. The method does not exhibit interference from other substances present in anti-perspirants and it shows a high precision with a R.S.D. value (n=6) of 0.9%. Moreover, the accuracy of the method was evaluated by comparison with a back complexometric titration method, which is currently used for routine analysis in pharmaceutical laboratories. The Student's t-test showed that the results obtained by both methods were not significantly different for a significance level of 95%. A response time of 12s and a sample analysis time, by performing triplicate injections, of 60s were achieved. The analytical figures of merit make the method highly appropriate to substitute the time-consuming complexometric method for this kind of analysis.

  17. Effects of adding injection-compression to rapid heat cycle molding on the structure of a light guide plate

    NASA Astrophysics Data System (ADS)

    Hong, Seokkwan; Min, Inki; Yoon, Kyunghwan; Kang, Jeongjin

    2014-01-01

    This study investigates the effects of adding injection-compression to rapid heat cycle molding (RHCM) (rapid heat cycle injection-compression molding (RICM)) on the physical quality and optical anisotropy of a molded light guide plate (LGP). Transcription ratio of microstructure, uniformity of part thickness and birefringence were experimentally evaluated on a 7 inch LGP of nominal thickness of 1.12 mm (including a microstructure array of 30 µm diameter and 14 µm height). The designed mold was equipped with rapid heating and compressing facilities and a microstructured nickel stamper was fabricated by UV LIGA process. In addition, to investigate the efficacy of RICM, experiments involving conventional injection molding (CIM), ICM, and RHCM were conducted in parallel with RICM using the same mold. RHCM and RICM yielded excellent transcription ratios for the microstructure, while CIM and RICM provided high thickness uniformity and low birefringence. Thus, RICM obtains high transcription ratio of microstructure, uniform thickness and low birefringence.

  18. Rapid and low-cost prototyping of medical devices using 3D printed molds for liquid injection molding.

    PubMed

    Chung, Philip; Heller, J Alex; Etemadi, Mozziyar; Ottoson, Paige E; Liu, Jonathan A; Rand, Larry; Roy, Shuvo

    2014-06-27

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications.

  19. Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

    PubMed Central

    Chung, Philip; Heller, J. Alex; Etemadi, Mozziyar; Ottoson, Paige E.; Liu, Jonathan A.; Rand, Larry; Roy, Shuvo

    2014-01-01

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications. PMID:24998993

  20. Conformal cooling and rapid thermal cycling in injection molding with 3D printed tools

    NASA Astrophysics Data System (ADS)

    Xu, Xiaorong

    Solid Freeform Fabrication processes such as 3D Printing have demonstrated the potential to produce tools with complex internal geometry. This work explores the application of this capability to improved thermal management for injection molding tooling through: (i)cooling lines which are conformal to the mold surface which provide improved uniformity and stability of mold temperature and (ii)tools with low thermal inertia which, in combination with conformal fluid channels allow for rapid heating and cooling of tooling, thereby facilitating isothermal filling of the mold cavity. This work presents a systematic, modular, approach to the design of conformal cooling channels. Recognizing that the cooling is local to the surface of the tool, the tool is divided up into geometric regions and a channel system is designed for each region. Each channel system is itself modeled as composed of cooling elements, typically the region spanned by two channels. Six criteria are applied including; a transient heat transfer condition which dictates a maximum distance from mold surface to cooling channel, considerations of pressure and temperature drop along the flow channel and considerations of strength of the mold. These criteria are treated as constraints and successful designs are sought which define windows bounded by these constraints. The methodology is demonstrated in application to a complex core and cavity for injection molding. In the area of rapid thermal cycling, this work utilizes the design methods for conformal channels for the heating phases and adds analysis of the packing and cooling phases. A design is created which provides thermal isolation and accommodation of cyclic thermal stresses though an array of bendable support columns which support the molding portion of the tool where the heating/cooling channels are contained. Designed elasticity of the tool is used to aid in packing of the polymer during the cooling phase. Methodology for the design of this

  1. Sequential injection analysis with chemiluminescence detection for rapid monitoring of commercial Calendula officinalis extractions.

    PubMed

    Hughes, Rachel R; Scown, David; Lenehan, Claire E

    2015-01-01

    Plant extracts containing high levels of antioxidants are desirable due to their reported health benefits. Most techniques capable of determining the antioxidant activity of plant extracts are unsuitable for rapid at-line analysis as they require extensive sample preparation and/or long analysis times. Therefore, analytical techniques capable of real-time or pseudo real-time at-line monitoring of plant extractions, and determination of extraction endpoints, would be useful to manufacturers of antioxidant-rich plant extracts. To develop a reliable method for the rapid at-line extraction monitoring of antioxidants in plant extracts. Calendula officinalis extracts were prepared from dried flowers and analysed for antioxidant activity using sequential injection analysis (SIA) with chemiluminescence (CL) detection. The intensity of CL emission from the reaction of acidic potassium permanganate with antioxidants within the extract was used as the analytical signal. The SIA-CL method was applied to monitor the extraction of C. officinalis over the course of a batch extraction to determine the extraction endpoint. Results were compared with those from ultra high performance liquid chromatography (UHPLC). Pseudo real-time, at-line monitoring showed the level of antioxidants in a batch extract of Calendula officinalis plateaued after 100 min of extraction. These results correlated well with those of an offline UHPLC study. SIA-CL was found to be a suitable method for pseudo real-time monitoring of plant extractions and determination of extraction endpoints with respect to antioxidant concentrations. The method was applied at-line in the manufacturing industry. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Advances in gelled-electrolyte technology for valve-regulated lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Lambert, D. W. H.; Greenwood, P. H. J.; Reed, M. C.

    In recent years, the valve-regulated lead-acid (VRLA) battery has been developed into a versatile and extremely reliable energy-storage device. When given a correctly specified battery design technology for the required product application, the VRLA battery will offer the end-user, some, if not all, of the following characteristics: high current capability; good reliability under cyclic, deep-discharge conditions (cycle life); good power density; high recharge efficiency; rapid rechargeability; resistant to overcharge; good charge stability (resistant to thermal runaway); no addition of water (topping-up) during service life (maintenance-free); long service life; wide operating temperature; robust design; low cost per Wh; high volumetric energy density (Wh/l); low self-discharge; high gravimetric energy density (Wh kg -1); may be stored and used in any position (orientation); resistant to shock and vibration; no need to be recharged immediately after discharge and environmentally 'safe'. The most commonly used gelling agent, fumed silica, has many disadvantages such as, contamination of the local working environment, particularly during paste-mixing, and occupational hygiene and handling problems. It is also bulky to transport and has long gel times unless used at very high concentrations. There is, therefore, an increasing demand for an alternative gelling agent for sulfuric acid in the production of gelled-electrolyte (GEL) VRLA batteries. Silica sols can provide a solution to all of these problems, and moreover at a lower cost to the battery producer.

  3. Sustained ocular delivery of brimonidine tartrate using ion activated in situ gelling system.

    PubMed

    Geethalakshmi, A; Karki, Roopa; Jha, Sajal Kumar; Venkatesh, D P; Nikunj, B

    2012-03-01

    The poor bioavailability and therapeutic response exhibited by conventional eye drops due to rapid precorneal elimination of the drug may be overcome by the use of an in situ gelling systems that are instilled as drops into the eye and undergo a sol-to-gel transition in the cul-de-sac which improves patient compliance as the dosage regimen is one drop of the dosage form twice a day. The loss of drug overcomes due to the immediate gel formation between the eye membrane and the drug being entrapped simultaneously in sol-gel transition in the cul de sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antiglaucomal agent, brimonidine tartrate based on the concept of ion-activated in situ gelation. Gelrite was used as the gelling agent, which gels in the presence of mono or divalent cations present in the lacrimal fluid. The formulations were evaluated for clarity, pH measurement, gelling capacity, drug content estimation, rheological study, in-vitro diffusion study, antibacterial activity, isotonicity testing, eye irritation testing. In the developed formulations Gelrite Brimonidine-3 (GB3) exhibited sustained release of drug from formulation over a period of 8 hrs thus increasing residence time of the drug, non-irritating with no ocular damage or abnormal clinical signs to the cornea, iris or conjunctiva, stable and sterile. These results demonstrate that the developed system is an alternative to conventional ophthalmic drops, with better patient compliance, and is industrially oriented and economical.

  4. Rapid resolution liquid chromatography for monitoring the quality of stockpiled atropine preparations for injection.

    PubMed

    Zimmermann, Thomas; Dimmel, Andre; Jüttemeyer, Sandra; Springer, Dietmar; Loch, Michael

    2012-01-01

    We describe a rapid resolution liquid chromatography (RRLC) method for analyzing atropine sulfate, its degradation products (tropic acid, apoatropine, atropic acid) and other components (e.g. phenol, methylparaben) in injectable medicines that are used by the German armed forces in emergency situations. Chromatography is performed using an acetonitrile/phosphate buffer gradient (pH = 1.0) and an RP 18 column (50 x 4.6 mm, 1.8 µm) with the detection wavelength set at 220 nm. The concentration of the active ingredient (atropine sulfate) in the tested products ranges from about 1 mg•ml(-1) to 10 mg•ml(-1) . The concentrations of the detected degradation products range from 0.2% to 4.7% (tropic acid) in relation to the active pharmaceutical ingredient (API). Using shorter separation columns and smaller particle sizes of the stationary phase improved analysis time from 40 to 10 min and reduced the consumption of solvents by approximately 75%. Owing to the pressure conditions (< 200 bar), UHPLC (ultra high performance liquid chromatography) systems are not needed. Comparison of the atropine and tropic acid results obtained with the previously used HPLC (high performance liquid chromatography) method of the MAH (marketing authorization holder) show that there is no indication of a significant difference between the two methods. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Rapid deglacial injection of nutrients into the tropical Atlantic via Antarctic Intermediate Water

    NASA Astrophysics Data System (ADS)

    Poggemann, David-Willem; Hathorne, Ed C.; Nürnberg, Dirk; Frank, Martin; Bruhn, Imke; Reißig, Stefan; Bahr, André

    2017-04-01

    As part of the return flow of the Atlantic overturning circulation, Antarctic Intermediate Water (AAIW) redistributes heat, salt, CO2 and nutrients from the Southern Ocean to the tropical Atlantic and thus plays a key role in ocean-atmosphere exchange. It feeds (sub)tropical upwelling linking high and low latitude ocean biogeochemistry but the dynamics of AAIW during the last deglaciation remain poorly constrained. We present new multi-decadal benthic foraminiferal Cd/Ca and stable carbon isotope (δ13 C) records from tropical W-Atlantic sediment cores indicating abrupt deglacial nutrient enrichment of AAIW as a consequence of enhanced deglacial Southern Ocean upwelling intensity. This is the first clear evidence from the intermediate depth tropical W-Atlantic that the deglacial reconnection of shallow and deep Atlantic overturning cells effectively altered the AAIW nutrient budget and its geochemical signature. The rapid nutrient injection via AAIW likely fed temporary low latitude productivity, thereby dampening the deglacial rise of atmospheric CO2.

  6. Rapid determination of carbohydrates in heroin drug seizures using capillary electrophoresis with short-end injection.

    PubMed

    Anastos, Nicole; Barnett, Neil W; Lewis, Simon W; Pearson, James R; Kirkbride, K Paul

    2005-09-01

    A simple and rapid method for the analysis of carbohydrates in heroin samples by capillary electrophoresis utilizing a borate complexation method is described. Separations were performed using an uncoated fused silica capillary, 50 cm x 50 micro I.D. x 360 microm O.D. with an effective separation length of 9 cm. The system was run at 60 degrees C with an applied voltage of -8 kilovolts. Injection of each sample was for 1 sec at -50 mbar. UV detection was employed with the wavelength set at 195 nm. The background electrolyte consisted of 65 mM borate, pH 12.0. Samples and standards were prepared in the run buffer containing 2 mg/mL of mannose as an internal standard. Under these conditions a test mixture containing glucose, sucrose, lactose, mannitol and mannose as an internal standard was resolved within 5 min. The method was used to determine the concentration of carbohydrates in heroin seizure samples and synthetic heroin samples. The results were in good agreement with the reported values.

  7. Rapid induction of dopamine sensitization in the nucleus accumbens shell induced by a single injection of cocaine.

    PubMed

    Singer, Bryan F; Bryan, Myranda A; Popov, Pavlo; Robinson, Terry E; Aragona, Brandon J

    2017-05-01

    Repeated intermittent exposure to cocaine results in the neurochemical sensitization of dopamine (DA) transmission within the nucleus accumbens (NAc). Indeed, the excitability of DA neurons in the ventral tegmental area (VTA) is enhanced within hours of initial psychostimulant exposure. However, it is not known if this is accompanied by a comparably rapid change in the ability of cocaine to increase extracellular DA concentrations in the ventral striatum. To address this question we used fast-scan cyclic voltammetry (FSCV) in awake-behaving rats to measure DA responses in the NAc shell following an initial intravenous cocaine injection, and then again 2-h later. Both injections quickly elevated DA levels in the NAc shell, but the second cocaine infusion produced a greater effect than the first, indicating sensitization. This suggests that a single injection of cocaine induces sensitization-related plasticity very rapidly within the mesolimbic DA system.

  8. Gelling properties of microparticulated whey proteins.

    PubMed

    Dissanayake, Muditha; Kelly, Alan L; Vasiljevic, Todor

    2010-06-09

    Subjecting whey proteins to high-pressure shearing with or without heating, commonly termed microparticulation, results in novel ingredients with modulated functionalities. Gelling properties of microparticulated whey proteins (MWP) were specifically assessed in this study. MWP powders were produced from commercial cheese whey retentate, standardized to 10% (w/w) protein, and subjected to microfluidization (MFZ) at 140 MPa either with or without prior heat-induced denaturation, followed by spray-drying. Gels were created from aqueous MWP dispersions either by heating at 90 degrees C for 20 min or by allowing gels to form at ambient temperature through addition of glucano-delta-lactone and/or NaCl. MWP powders produced from unheated WP dispersions created firm gels upon heating, whereas those produced from denatured WP gave only cold-set gels. Covalent and noncovalent protein-protein interactions were involved during both heat- and cold-induced gelation. Hydrophobic interactions were more pronounced during aggregation of bovine serum albumin. In conclusion, microparticulation of WP resulted in heat- and cold-set gels with different molecular and physical characteristics from those of untreated controls.

  9. Intra-lesional injection of the novel PKC activator EBC-46 rapidly ablates tumors in mouse models.

    PubMed

    Boyle, Glen M; D'Souza, Marjorie M A; Pierce, Carly J; Adams, Ryan A; Cantor, Aaron S; Johns, Jenny P; Maslovskaya, Lidia; Gordon, Victoria A; Reddell, Paul W; Parsons, Peter G

    2014-01-01

    Intra-lesional chemotherapy for treatment of cutaneous malignancies has been used for many decades, allowing higher local drug concentrations and less toxicity than systemic agents. Here we describe a novel diterpene ester, EBC-46, and provide preclinical data supporting its use as an intra-lesional treatment. A single injection of EBC-46 caused rapid inflammation and influx of blood, followed by eschar formation and rapid tumor ablation in a range of syngeneic and xenograft models. EBC-46 induced oxidative burst from purified human polymorphonuclear cells, which was prevented by the Protein Kinase C inhibitor bisindolylmaleimide-1. EBC-46 activated a more specific subset of PKC isoforms (PKC-βI, -βII, -α and -γ) compared to the structurally related phorbol 12-myristate 13-acetate (PMA). Although EBC-46 showed threefold less potency for inhibiting cell growth than PMA in vitro, it was more effective for cure of tumors in vivo. No viable tumor cells were evident four hours after injection by ex vivo culture. Pharmacokinetic profiles from treated mice indicated that EBC-46 was retained preferentially within the tumor, and resulted in significantly greater local responses (erythema, oedema) following intra-lesional injection compared with injection into normal skin. The efficacy of EBC-46 was reduced by co-injection with bisindolylmaleimide-1. Loss of vascular integrity following treatment was demonstrated by an increased permeability of endothelial cell monolayers in vitro and by CD31 immunostaining of treated tumors in vivo. Our results demonstrate that a single intra-lesional injection of EBC-46 causes PKC-dependent hemorrhagic necrosis, rapid tumor cell death and ultimate cure of solid tumors in pre-clinical models of cancer.

  10. Intra-Lesional Injection of the Novel PKC Activator EBC-46 Rapidly Ablates Tumors in Mouse Models

    PubMed Central

    Pierce, Carly J.; Adams, Ryan A.; Cantor, Aaron S.; Johns, Jenny P.; Maslovskaya, Lidia; Gordon, Victoria A.; Reddell, Paul W.; Parsons, Peter G.

    2014-01-01

    Intra-lesional chemotherapy for treatment of cutaneous malignancies has been used for many decades, allowing higher local drug concentrations and less toxicity than systemic agents. Here we describe a novel diterpene ester, EBC-46, and provide preclinical data supporting its use as an intra-lesional treatment. A single injection of EBC-46 caused rapid inflammation and influx of blood, followed by eschar formation and rapid tumor ablation in a range of syngeneic and xenograft models. EBC-46 induced oxidative burst from purified human polymorphonuclear cells, which was prevented by the Protein Kinase C inhibitor bisindolylmaleimide-1. EBC-46 activated a more specific subset of PKC isoforms (PKC-βI, -βII, -α and -γ) compared to the structurally related phorbol 12-myristate 13-acetate (PMA). Although EBC-46 showed threefold less potency for inhibiting cell growth than PMA in vitro, it was more effective for cure of tumors in vivo. No viable tumor cells were evident four hours after injection by ex vivo culture. Pharmacokinetic profiles from treated mice indicated that EBC-46 was retained preferentially within the tumor, and resulted in significantly greater local responses (erythema, oedema) following intra-lesional injection compared with injection into normal skin. The efficacy of EBC-46 was reduced by co-injection with bisindolylmaleimide-1. Loss of vascular integrity following treatment was demonstrated by an increased permeability of endothelial cell monolayers in vitro and by CD31 immunostaining of treated tumors in vivo. Our results demonstrate that a single intra-lesional injection of EBC-46 causes PKC-dependent hemorrhagic necrosis, rapid tumor cell death and ultimate cure of solid tumors in pre-clinical models of cancer. PMID:25272271

  11. Acceptability of rapid oral fluid HIV testing among male injection drug users in Taiwan, 1997 and 2007.

    PubMed

    Lyu, Shu-Yu; Morisky, Donald E; Yeh, Ching-Ying; Twu, Shiing-Jer; Peng, Eugene Yu-Chang; Malow, Robert M

    2011-04-01

    Rapid oral fluid HIV testing (rapid oral testing) is in the process of being adapted in Taiwan and elsewhere given its advantages over prior HIV testing methods. To guide this process, we examined the acceptability of rapid oral testing at two time points (i.e., 1997 and 2007) among one of the highest risk populations, male injection drug users (IDUs). For this purpose, an anonymous self-administered survey was completed by HIV-negative IDUs involved in the criminal justice system in 1997 (N (1)=137 parolees) and 2007 (N (2)=106 prisoners). A social marketing model helped guide the design of our questionnaire to assess the acceptability of rapid oral testing. This included assessing a new product, across four marketing dimensions: product, price, promotion, and place. Results revealed that in both 1997 and 2007, over 90% indicated that rapid oral testing would be highly acceptable, particularly if the cost was under US$6, and that a pharmacy would be the most appropriate and accessible venue for selling the rapid oral testing kits. The vast majority of survey respondents believed that the cost of rapid oral testing should be federally subsidized and that television and newspaper advertisements would be the most effective media to advertise for rapid oral testing. Both the 1997 and 2007 surveys suggested that rapid oral HIV testing would be particularly accepted in Taiwan by IDUs after release from the criminal justice system.

  12. Liquid oxygen/metal gelled monopropellants

    NASA Technical Reports Server (NTRS)

    Wickman, John H.

    1991-01-01

    The objectives of this program were to establish the feasibility of metallized/liquid oxygen monopropellants and select the best monopropellant formulation for continued study. The metal powders mixed with the liquid oxygen were aluminum/magnesium (80/20), silicon and iron (Iron was only tested for burning properties). The formulations were first evaluated on whether they detonated when ignited or burned. The formulations only burned when ignited. The viscosity for the formulations ranged from 900 cps to 100 cps at shear rates up to 300 seconds(sup -1). Two percent (by weight) of Cab-O-Sil was added to the aluminum and aluminum/magnesium formulations for gelling while the silicon formulation used three percent. Within a seven hour period, settling was suggested only in the 29 percent aluminum and 29 percent aluminum/magnesium formulations. The monopropellants were burned in a cylinder submerged in a liquid nitrogen bath. Experimental data at ambient pressure indicated that the monopropellants were extinguished when the flame front reached regions submerged under the liquid nitrogen. The burn rate increased dramatically when burned in a cylinder enclosure with less heat sink available to the monopropellant. The test results were inconclusive as to whether the increased burn rate was due to the lower heat sink capacity or the small amount of pressure (2 psi) generated during the burning of the monopropellant. The burning of the aluminum and aluminum/magnesium resulted in a brilliant white flame similar to that of an arc welder. These monopropellants burned in a pulsating manner with the aluminum/magnesium appearing to have less pulsating combustion. The silicon monopropellant burned with an orange glow. No sparks or energetic burning was apparent as with the aluminum or aluminum/magnesium.

  13. Improved Pharmacokinetic and Pharmacodynamic Profile of Rapid-Acting Insulin Using Needle-Free Jet Injection Technology

    PubMed Central

    Engwerda, Elsemiek E.C.; Abbink, Evertine J.; Tack, Cees J.; de Galan, Bastiaan E.

    2011-01-01

    OBJECTIVE Insulin administered by jet injectors is dispensed over a larger subcutaneous area than insulin injected with a syringe, which may facilitate a more rapid absorption. This study compared the pharmacologic profile of administration of insulin aspart by jet injection to that by conventional insulin pen. RESEARCH DESIGN AND METHODS Euglycemic glucose clamp tests were performed in 18 healthy volunteers after subcutaneous administration of 0.2 units/kg body wt of aspart, either administered by jet injection or by conventional pen, using a randomized, double-blind, double-dummy, cross over study design. Pharmacodynamic and pharmacokinetic profiles were derived from the glucose infusion rate (GIR) needed to maintain euglycemia and from plasma insulin levels, respectively. RESULTS The time to maximal GIR was significantly shorter when insulin was injected with the jet injector compared with conventional pen administration (51 ± 3 vs. 105 ± 11 min, P < 0.0001). The time to peak insulin concentration was similarly reduced (31 ± 3 vs. 64 ± 6 min, P < 0.0001) and peak insulin concentrations were increased (108 ± 13 vs. 79 ± 7 mU/L, P = 0.01) when insulin was injected by jet injection compared with conventional pen injection. Jet injector insulin administration reduced the time to 50% glucose disposal by ∼40 min (P < 0.0001). There were no differences in maximal GIR, total insulin absorption, or total insulin action between the two devices. CONCLUSIONS Administration of insulin aspart by jet injection enhances insulin absorption and reduces the duration of glucose-lowering action. This profile resembles more closely the pattern of endogenous insulin secretion and may help to achieve better meal insulin coverage and correction of postprandial glucose excursions. PMID:21715522

  14. Gelled polymer systems for permeability modification in petroleum reservoirs

    SciTech Connect

    Willhite, G.P.; Green, D.W.; Thiele, J.L.; McCool, C.S.; Mertes, K.B.

    1991-09-01

    The research program described in this report was conducted to improve the performance and predictability of in situ gelation processes designed to increase volumetric sweep efficiency of fluid displacement processes. A principal objective of this research was to develop procedures for design and evaluation of permeability modification processes. Research was conducted in three broad areas: (1) Physical and Chemical Characterization of Gelling Systems (2) In situ Gelation and (3) Mathematical Modeling of In Site Gelation. Gelling systems used chromium as the crosslinking agent. Polyacrylamide and polysaccharides gelling systems were studied. Research was conducted on the chemical structure of polymer/metal ion complexes, kinetics of the reduction of Cr(6) to Cr(3) by thiourea, kinetics of oligomerization and uptake of chromium by polyacrylamide and rheology of chromium/polysaccharide gelling systems. Studies of polymer/metal ion complexes were conducted using solutions of pure monomer, dimer and trimer forms of chromium. A mathematical model was developed to examine the kinetics of Cr(3) oligomerization and uptake of chromium by polyacrylamide. Rheological studies were completed on chromium/polysaccharide gels. In situ gelation experiments were conducted using a bis-ethylenediamine chromium complex and chromium(3) polyacrylamide gelling systems in sandpacks. A numerical model of in situ gelation of chromium/polyacrylamide systems was developed for linear displacement in a sandpack. The numerical model is based on filtration mechanisms and is consistent with experimental data and models developed in this research program. 103 figs., 21 tabs.

  15. Implementation of rapid HIV and HCV testing within harm reduction programmes for people who inject drugs: a pilot study.

    PubMed

    Fernàndez-López, Laura; Folch, Cinta; Majó, Xavier; Gasulla, Laia; Casabona, Jordi

    2016-01-01

    Including HCV and HIV rapid tests in harm reduction programmes (HRP) for people who inject drugs (PWID) can increase detection of these infections in high-risk populations who do not seek conventional health care. To assess acceptability and feasibility of rapid HIV and HCV tests in HRP; to identify HIV and HCV prevalence rates in HRP; to identify the percentage of PWID with a reactive test that attend hospital for confirmation and follow-up. Rapid oral tests for HCV and HIV were offered to users of 13 HRP from both mobile units and facility-based centres. A total of 172 HCV and 198 HIV tests were performed, with a refusal rate of 1.7% and 10.4%, respectively. Injectors made up 64.9% of all drug users and 35.1% did not inject drugs. Overall, 20.3% of HCV tests and 2.5% of HIV test were reactive. Only 24 of the 35 reactive HCV could be confirmed (68.6%) and one was false-negative. Of the five HIV reactive cases, only two could be confirmed (40%) with 1 false-positive case. Acceptability of rapid HIV and HCV tests among HRP users was high. The usefulness of oral rapid tests in HRP has been demonstrated, especially in mobile HRP.

  16. Metallized Gelled Propellants Combustion Experiments in a Pulse Detonation Engine

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan; Jurns, John; Breisacher, Kevin; Kearns, Kim

    2006-01-01

    A series of combustion tests were performed with metallized gelled JP 8/aluminum fuels in a Pulse Detonation Engine (PDE). Nanoparticles of aluminum were used in the 60 to 100 nanometer diameter. Gellants were also of a nanoparticulate type composed of hydrocarbon alkoxide materials. Using simulated air (a nitrogen-oxygen mixture), the ignition potential of metallized gelled fuels with nanoparticle aluminum was investigated. Ignition of the JP 8/aluminum was possible with less than or equal to a 23-wt% oxygen loading in the simulated air. JP 8 fuel alone was unable to ignite with less than 30 percent oxygen loaded simulated air. The tests were single shot tests of the metallized gelled fuel to demonstrate the capability of the fuel to improve fuel detonability. The tests were conducted at ambient temperatures and with maximal detonation pressures of 1340 psia.

  17. High energy, low temperature gelled bi-propellant formulation

    NASA Technical Reports Server (NTRS)

    Di Salvo, Roberto (Inventor)

    2011-01-01

    The present invention is a bi-propellant system comprising a gelled liquid propane (GLP) fuel and a gelled MON-30 (70% N.sub.2O.sub.4+30% NO) oxidizer. The bi-propellant system is particularly well-suited for outer planet missions greater than 3 AU from the sun and also functions in earth and near earth environments. Additives such as powders of boron, carbon, lithium, and/or aluminum can be added to the fuel component to improve performance or enhance hypergolicity. The gelling agent can be silicon dioxide, clay, carbon, or organic or inorganic polymers. The bi-propellant system may be, but need not be, hypergolic.

  18. Experimental comparative study of doublet and triplet impinging atomization of gelled fuel based on PIV

    NASA Astrophysics Data System (ADS)

    Yang, Jian-lu; Li, Ning; Weng, Chun-sheng

    2016-10-01

    Gelled propellant is promising for future aerospace application because of its combination of the advantages of solid propellants and liquid propellants. An effort was made to reveal the atomization properties of gelled fuel by particle image velocimetry (PIV) system. The gelled fuel which was formed by gasoline and Nano-silica was atomized using a like-doublet impingement injector and an axisymmetric like-triplet impingement injector. The orifice diameter and length of the nozzle used in this work were of 0.8mm, 4.8mm, respectively. In the impinging spray process, the impingement angles were set at 90° and 120°, and the injection pressures were of 0.50MPa and 1.00MPa. The distance from the exit of the orifice to the impingement point was fixed at 9.6mm. In this study, high-speed visualization and temporal resolution particle image velocimetry techniques were employed to investigate the impingement atomization characteristics. The experimental investigation demonstrated that a long narrow high speed droplets belt formed around the axis of symmetry in the like-doublet impinging atomization area. However, there was no obvious high-speed belt with impingement angle 2θ = 90° and two high-speed belts appeared with impingement angle 2θ = 120° in the like-doublet impingement spray field. The high droplet velocity zone of the like-doublet impingement atomization symmetrically distributed around the central axis, and that of the like-triplet impingement spray deflected to the left of the central axis - opposite of injector. Although the droplets velocity distribution was asymmetry of like-triplet impingement atomization, the injectors were arranged like axisymmetric conical shape, and the cross section of spray area was similar to a circle rather than a narrow rectangle like the like-doublet impingement atomization.

  19. A rapid and low-cost approach to evaluate the allergenicity of herbal injection using HPLC analysis.

    PubMed

    Yu, Li; Peng, Guoping; Li, Cunyu; Jiang, Baoping; Xu, Haokun; Ding, Ning; Zheng, Yunfeng; Leng, John Q

    2013-07-01

    Herbal medicines have ever been thought harmless, but it is obviously not true. Many adverse reports emerged with the development of their popular application in the world. Allergic reactions, especially serious immediate hypersensitivity, frequently occurred when herbal injections were used in clinic and made this ever prevailing agent nearly disappear in China. The aim of this study is to establish a rapid and economical method for the prediction of the allergenicity of herbal injections. Ovalbumin (OVA) and four other herbal injections, in which two of them were well known for their allergenicity, were selected to sensitize and stimulate the animals. Serotonin in the animal serum was detected with HPLC to reflect the anaphylactic response and compared with the other cytokines which could mediate the anaphylaxis, including histamine, IgE and β-hexosaminidase. The results suggest that serotonin can be detected quickly and has good correlation with the other allergy-related cytokines. It is a promising way for predicting the allergenicity of the herbal injections and those complicated natural products.

  20. A rapid and accurate method for determining protein content in dairy products based on asynchronous-injection alternating merging zone flow-injection spectrophotometry.

    PubMed

    Liang, Qin-Qin; Li, Yong-Sheng

    2013-12-01

    An accurate and rapid method and a system to determine protein content using asynchronous-injection alternating merging zone flow-injection spectrophotometry based on reaction between coomassie brilliant blue G250 (CBBG) and protein was established. Main merit of our approach is that it can avoid interferences of other nitric-compounds in samples, such as melamine and urea. Optimized conditions are as follows: Concentrations of CBBG, polyvinyl alcohol (PVA), NaCl and HCl are 150 mg/l, 30 mg/l, 0.1 mol/l and 1.0% (v/v), respectively; volumes of the sample and reagent are 150 μl and 30 μl, respectively; length of a reaction coil is 200 cm; total flow rate is 2.65 ml/min. The linear range of the method is 0.5-15 mg/l (BSA), its detection limit is 0.05 mg/l, relative standard deviation is less than 1.87% (n=11), and analytical speed is 60 samples per hour.

  1. Rapid induction of malignant tumor in Sprague-Dawley rats by injection of RK3E-ras cells.

    PubMed

    Kim, Soo-A; Kim, Hyun-Woo; Kim, Do-Kyung; Kim, Su-Gwan; Park, Joo-Cheol; Kang, Dong-Wan; Kim, Si-Wouk; Ahn, Sang-Gun; Yoon, Jung-Hoon

    2006-04-08

    Several tumor animal models have been provided as a tool for developing cancer therapy. Here, we developed rapid, easy-to use, and cost-effective new rat animal model for invasion and metastasis of cancer using genetically k-ras-induced rat kidney cells (RK3E-ras). We observed tumor as early as 3 days after injection of RK3E-ras cells in subcutaneous of Sprague-Dawley rats. Tumor size and volume were increased exponentially for 2 weeks. The tail vein injected rats obtained the lethal infiltration in the lung within 2 weeks. This tumor animal model has great potential for studying cancer processes and short-term screening of variable cancer therapy strategy.

  2. Rats markedly escalate their intake and show a persistent susceptibility to reinstatement only when cocaine is injected rapidly

    PubMed Central

    Wakabayashi, Ken T.; Weiss, Mark J.; Pickup, Kristen N.; Robinson, Terry E.

    2010-01-01

    When drugs enter the brain rapidly liability for addiction is increased, but why this is the case is not well understood. Here we examined the influence of varying the speed of intravenous cocaine delivery on self-administration behavior in rats given limited or extended opportunity to take drug. The speed of cocaine delivery had no effect on self-administration behavior when rats were given only 1 hr each day to take cocaine. When given 6-fold more time to take cocaine rats that received cocaine rapidly (5 – 45 sec) increased their total intake 8-fold. However, rats that received cocaine more slowly (over 90 sec) did not avail themselves of the opportunity to take much more drug – they increased their intake only 2-fold. Furthermore, when tested 45 days after the last self-administration session a drug priming injection reinstated drug-seeking behavior only in rats that in the past had cocaine injected rapidly (5 sec), and this was associated with a persistent suppression in the ability of cocaine to induce immediate early gene expression. Cocaine may be potentially more addictive when it reaches the brain rapidly because (1) this promotes a marked escalation in intake and (2) it renders individuals more susceptible to relapse long after the discontinuation of drug use. This is presumably because the rapid uptake of drug to the brain preferentially promotes persistent changes in brain systems that regulate motivation for drug, and continuing exposure to large amounts of drug produces a vicious cycle of further maladaptive changes in brain and behavior. PMID:20739555

  3. Rapidly Progressive Muscle Paralysis and Acute Respiratory Failure Following Endoscopic Botulinum Toxin Injection

    PubMed Central

    Khan, Ahmed; Shor, Julia; Forester, Gary P.

    2016-01-01

    Botulism toxin injection (BTI) is a well-known and relatively safe endoscopic treatment for achalasia. We report a case of a 90-year-old female diagnosed with achalasia who subsequently underwent BTI with symptomatic relief. The therapy was complicated by systemic botulism, however, leading to progressive muscle paralysis with diaphragmatic involvement requiring mechanical ventilation support. This is the first reported case of BTI for achalasia causing systemic botulism. PMID:27921065

  4. Rapid detection of bacteria in urine samples by the "three-plug-injection" method using capillary electrophoresis.

    PubMed

    Song, Lin; Li, Wanchen; Li, Guoxia; Wei, Dianjun; Ge, Peng; Li, Guizhen; Zheng, Fang; Sun, Xuguo

    2013-09-15

    This study explored a method that can rapidly detect bacteria in urine samples for the auxiliary determination of urinary tract infections (UTIs). Urine samples from patients with UTIs (230 cases) were obtained using aseptic technique. The urine biochemical assay was then carried out using an automated urine analyzer for all the urine samples. Bacterial species were identified by a combination of bacterial culture technique, morphological observation and the BACT-IST microbial identification/susceptibility analysis system. The most common seven species of bacteria in the study included Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, Enterococcus faecalis, Staphylococcus aureus and Staphylococcus epidermidis. Bacterial samples were suspended in sample buffer solutions and separated by the "three-plug-injection" method using capillary electrophoresis (CE). Each species of bacteria appeared as a bacterial peak. The mixture of the seven species also provided only one peak. Further analysis showed that the concentration limit for the "three-plug-injection" method is 10(6) colony forming units (CFU)/mL, and there is a good linear relationship between the peak height and bacterial concentration (R(2)=0.99). The effect of urine composition on CE results was also investigated. The results showed that urine composition, i.e., proteins, white blood cells (WBCs) and red blood cells (RBCs), affected the peak retention time but could not affect the separation of bacteria. The results demonstrated that the bacteria in urine samples can be detected within 10min by the "three-plug-injection" method using CE. The "three-plug-injection" method is therefore suitable for the rapid detection of organisms in clinical urine samples from UTIs.

  5. Application of Rapid Prototyping and Wire Arc Spray to the Fabrication of Injection Mold Tools (MSFC Center Director's Discretionary Fund)

    NASA Technical Reports Server (NTRS)

    Cooper, K. G.

    2000-01-01

    Rapid prototyping (RP) is a layer-by-layer-based additive manufacturing process for constructing three-dimensional representations of a computer design from a wax, plastic, or similar material. Wire arc spray (WAS) is a metal spray forming technique, which deposits thin layers of metal onto a substrate or pattern. Marshall Space Flight Center currently has both capabilities in-house, and this project proposed merging the two processes into an innovative manufacturing technique, in which intermediate injection molding tool halves were to be fabricated with RP and WAS metal forming.

  6. Progress in the development of gelling agents for improved culturability of microorganisms.

    PubMed

    Das, Nabajit; Tripathi, Naveen; Basu, Srijoni; Bose, Chandra; Maitra, Susmit; Khurana, Sukant

    2015-01-01

    Gelling agents are required for formulating both solid and semisolid media, vital for the isolation of microorganisms. Gelatin was the first gelling agent to be discovered but it soon paved the way for agar, which has far superior material qualities. Source depletion, issues with polymerase-chain-reaction and inability to sustain extermophiles etc., necessitate the need of other gelling agents. Many new gelling agents, such as xantham gum, gellan gum, carrageenan, isubgol, and guar gum have been formulated, raising the hopes for the growth of previously unculturable microorganisms. We evaluate the progress in the development of gelling agents, with the hope that our synthesis would help accelerate research in the field.

  7. Rapid Inward Impurity Transport during Impurity Pellet Injection on the DIII-D Tokamak

    SciTech Connect

    Evans, T.E.; Hyatt, A.W.; Lee, R.L.; Kellman, A.G.; Parks, P.B.; Stockdale, R.; Taylor, P.L.; Whyte, D.G.; Jernigan, T.C.

    1998-11-01

    Neon killer pellets are injected into the DIII-D tokamak plasma in order to radiatively quench the plasma{close_quote}s stored energy and mitigate disruption effects. Inward radial transport on the time scale of the pellet ablation ({le}1 ms) results in central deposition of the neon inside the ablation penetration radius of the pellet, causing effective radiative energy dissipation. This result is in contrast to the radially outward deposition measured for fueling (hydrogenic) pellets. The observed magnitudes of magnetic fluctuations ({delta}B/B{approximately}0.2{percent}) are shown to be capable of causing the radial transport. {copyright} {ital 1998} {ital The American Physical Society }

  8. Hydrosoluble, UV-crosslinkable and injectable chitosan for patterned cell-laden microgel and rapid transdermal curing hydrogel in vivo.

    PubMed

    Li, Baoqiang; Wang, Lei; Xu, Feng; Gang, Xiaomin; Demirci, Utkan; Wei, Daqing; Li, Ying; Feng, Yujie; Jia, Dechang; Zhou, Yu

    2015-08-01

    Natural and biodegradable chitosan with unique amino groups has found widespread applications in tissue engineering and drug delivery. However, its applications have been limited by the poor solubility of native chitosan in neutral pH solution, which subsequently fails to achieve cell-laden hydrogel at physiological pH. To address this, we incorporated UV crosslinking ability in chitosan, allowing fabrication of patterned cell-laden and rapid transdermal curing hydrogel in vivo. The hydrosoluble, UV crosslinkable and injectable N-methacryloyl chitosan (N-MAC) was synthesized via single-step chemoselective N-acylation reaction, which simultaneously endowed chitosan with well solubility in neutral pH solution, UV crosslinkable ability and injectability. The solubility of N-MAC in neutral pH solution increased 2.21-fold with substitution degree increasing from 10.9% to 28.4%. The N-MAC allowed fabrication of cell-laden microgels with on-demand patterns via photolithography, and the cell viability in N-MAC hydrogel maintained 96.3 ± 1.3% N-MAC allowed rapid transdermal curing hydrogel in vivo within 60s through minimally invasive clinical surgery. Histological analysis revealed that low-dose UV irradiation hardly induced skin injury and acute inflammatory response disappeared after 7 days. N-MAC would allow rapid, robust and cost-effective fabrication of patterned cell-laden polysaccharide microgels with unique amino groups serving as building blocks for tissue engineering and rapid transdermal curing hydrogel in vivo for localized and sustained protein delivery. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  9. Rapid control of mold temperature during injection molding process: Effect of packing pressure

    NASA Astrophysics Data System (ADS)

    Liparoti, Sara; Sorrentino, Andrea; Titomanlio, Giuseppe

    2015-12-01

    A thorough analysis of the effect of operative conditions of injection molding process on the morphology distribution inside the obtained molded is performed, with particular reference to semi- crystalline polymers. In particular, fully characterized injection molding tests are presented using an isotactic polypropylene, previously carefully characterized as far as most of properties of interest. The effects of mold temperature and packing conditions are analyzed. The mold temperature was controlled by a thin heating device, composed by polyimide as insulating layer and polyimide loaded carbon black as electrical conductive layer, that is able to increase temperature on mold surface in few seconds (70°C/s) by joule effect and cool down soon after. The shear layer thickness in the molded is reduced in the samples produced at high mold temperatures, that means high electrical power and long heating time, and this reduction is more significant at lower packing pressures, indeed, at 360bar as packing pressure and 20s as heating time the shear layer disappear. The resulting morphology was analyzed by optical microscope.

  10. Current Injection Provokes Rapid Expansion of the Guard Cell Cytosolic Volume and Triggers Ca(2+) Signals.

    PubMed

    Voss, Lena J; Hedrich, Rainer; Roelfsema, M Rob G

    2016-03-07

    High-resolution microscopy opens the door for detailed single-cell studies with fluorescent reporter dyes and proteins. We used a confocal spinning disc microscope to monitor fluorescent dyes and the fluorescent protein Venus in tobacco and Arabidopsis guard cells. Multi-barreled microelectrodes were used to inject dyes and apply voltage pulses, which provoke transient rises in the cytosolic Ca(2+) level. Voltage pulses also caused changes in the distribution of Lucifer Yellow and Venus, which pointed to a reversible increase of guard cell cytosolic volume. The dynamic cytosolic volume changes turned out to be provoked by current injection of ions. A reduction of the clamp current, by blocking K(+) uptake channels with Cs(+), strongly suppressed the cytosolic volume changes. Cs(+) not only inhibited the expansion of the cytosol, but also inhibited hyperpolarization-induced elevations of the cytosolic Ca(2+) concentration. A complete loss of voltage-induced Ca(2+) signals occurred when Ca(2+)-permeable plasma membrane channels were simultaneously blocked with La(3+). This shows that two mechanisms cause hyperpolarization-induced elevation of the cytosolic Ca(2+)-concentration: (i) activation of voltage-dependent Ca(2+)-permeable channels, (ii) osmotically induced expansion of the cytosol, which leads to a release of Ca(2+) from intracellular stores. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  11. Ion-activated In Situ Gelling Ophthalmic Delivery Systems of Azithromycin

    PubMed Central

    Vijaya, C.; Goud, K. Swetha

    2011-01-01

    Gelation of pectin caused by divalent cations especially calcium ions has been applied to develop an ophthalmic formulation of azithromycin in the present study. Rapid elimination of drug on instillation into cul de sac would be minimal with in situ gelling ophthalmic solution leading to increased precorneal contact time and prolonged drug delivery. In the formulation development studies pectin was used in different concentrations (1-5% w/v) and different proportions of the hydrocolloids hydroxypropyl methylcellulose and sodium carboxymethyl cellulose of different grades of viscosity were used. The primary criteria for formulation optimization were gelling capacity and rheological behaviour. In addition, formulations were evaluated for pH, and antimicrobial efficacy and drug release. The clarity, pH, gelation in simulated tear fluid and rheological properties of the optimized formulations were satisfactory. The formulations inhibited the growth of Staphylococcus aureus effectively in cup–plate method and were proved to be safe and non irritant on rabbit eyes. The results indicate that pectin based in situ gels can be successfully used to prolong the duration of action of azithromycin. PMID:23112394

  12. Mucoadhesive in situ nasal gelling drug delivery systems for modulated drug delivery.

    PubMed

    Singh, Reena M P; Kumar, Anil; Pathak, Kamla

    2013-01-01

    The nasal route is an attractive target for administration of the drug of choice, particularly in overcoming disadvantages such as high first-pass metabolism and drug degradation in the gastrointestinal environment that are associated with the oral and other modes of administration. The major limitation associated is of rapid mucociliary clearance in the nasal delivery that results in low absorption and hence poor bioavailability. In order to overcome this, mucoadhesive in situ nasal gelling drug delivery systems have been explored to develop sustained/controlled delivery via nasal route. The present review critically evaluates the importance of in situ gel for the nasal delivery of drugs, and the polymers used in the formulation of in situ gel along with their mechanism of gelation. It also encompasses the research reports made in this arena of delivery system. The challenges of drug delivery through nose has led to development of in situ nasal gelling systems using a myriad of polymers to deliver the drugs, proteins, amino acids, hormones, vaccines and plasmid DNA for the local, systemic and central nervous system effects. Though a range of preclinical reports are available, clinical intricacies need to be critically worked out.

  13. Rapidly Polymerizing Injectable Click Hydrogel Therapy to Delay Bone Growth in a Murine Re-synostosis Model

    PubMed Central

    Hermann, Christopher D.; Wilson, David S.; Lawrence, Kelsey A.; Ning, Xinghai; Olivares-Navarrete, Rene; Williams, Joseph K.; Guldberg, Robert E.; Murthy, Niren; Schwartz, Zvi; Boyan, Barbara D.

    2014-01-01

    Craniosynostosis is the premature fusion of cranial sutures, which can result in progressive cranial deformations, increased intracranial pressure, and restricted brain growth. Most cases of craniosynostosis require surgical reconstruction of the cranial vault with the goal of increasing the intracranial volume and correcting the craniofacial deformities. However, patients often experience rapid post-operative bone re-growth, known as re-synostosis, which necessitates additional surgical intervention. Bone morphogenic protein (BMP) inhibitors have tremendous potential to treat re-synostosis, but the realization of a clinically viable inhibitor-based therapeutic requires the development of a delivery vehicle that can localize the release to the site of administration. Here, we present an in situ rapidly crosslinking injectable hydrogel that has the properties necessary to encapsulate co-administered proteins and demonstrate that the delivery of rmGremlin1 via our hydrogel system delays bone re-growth in a weanling mouse model of re-synostosis. Our hydrogel is composed of two mutually reactive poly(ethylene glycol) macromolecules, which when mixed crosslink via a bio-orthogonal Cu free click reaction. Hydrogels containing Gremlin caused a dose-dependent inhibition of bone regrowth. In addition to craniofacial applications, our injectable click hydrogel has the potential to provide customizable protein, small molecule, and cell delivery to any site accessible via needle or catheter. PMID:25176067

  14. On the rapid estimation of % ash in coal from silicon content obtained via FNAA, XRF, or Slurry-injection AA

    NASA Astrophysics Data System (ADS)

    Hicks, D. G.; O'Reilly, J. E.; Kopenaal, D. W.

    1981-02-01

    The high-temperature ash levels of some typical U. S. bituminous coals can be rapidly estimated with a standard error (absolute) of 1.7% ash from simple linear correlations between % Si and % ash. Si contents may be rapidly determine by Fast Neutron Activation Analysis (FNAA), X-Ray Flourescence (XRF), or Slurry-Injection Atomic Absorption Spectrometry (SIAAS) methods requiring little more sample preparation other than a brief grinding and weighing. These three instrumental methods showed roughly equivalent correlations. In contrast to earlier reports, logarithmic plots do not produce improved estimates. Also, correlations do not seem to be significantly improved by selecting coals within one rank or from one geographical area. The slurry-injection atomic absorption method does not require significant modifications of existing commercial AA instruments. The conventional method for determining ash content of coal, though simple and accurate, requires a considerable amount of time in the laboratory. Ash content of coals is an important parameter related to their eventual use as fuels, as feedstocks in liquefaction and gasification processes, and in metallurgical processes.

  15. Rapid Adiabatic Preparation of Injective Projected Entangled Pair States and Gibbs States

    NASA Astrophysics Data System (ADS)

    Ge, Yimin; Molnár, András; Cirac, J. Ignacio

    2016-02-01

    We propose a quantum algorithm for many-body state preparation. It is especially suited for injective projected entangled pair states and thermal states of local commuting Hamiltonians on a lattice. We show that for a uniform gap and sufficiently smooth paths, an adiabatic runtime and circuit depth of O (polylog N ) can be achieved for O (N ) spins. This is an almost exponential improvement over previous bounds. The total number of elementary gates scales as O (N p o l y l o g N ) . This is also faster than the best known upper bound of O (N2) on the mixing times of Monte Carlo Markov chain algorithms for sampling classical systems in thermal equilibrium.

  16. Interactive visual steering--rapid visual prototyping of a common rail injection system.

    PubMed

    Matković, Kresimir; Gracanin, Denis; Jelović, Mario; Hauser, Helwig

    2008-01-01

    Interactive steering with visualization has been a common goal of the visualization research community for twenty years, but it is rarely ever realized in practice. In this paper we describe a successful realization of a tightly coupled steering loop, integrating new simulation technology and interactive visual analysis in a prototyping environment for automotive industry system design. Due to increasing pressure on car manufacturers to meet new emission regulations, to improve efficiency, and to reduce noise, both simulation and visualization are pushed to their limits. Automotive system components, such as the powertrain system or the injection system have an increasing number of parameters, and new design approaches are required. It is no longer possible to optimize such a system solely based on experience or forward optimization. By coupling interactive visualization with the simulation back-end (computational steering), it is now possible to quickly prototype a new system, starting from a non-optimized initial prototype and the corresponding simulation model. The prototyping continues through the refinement of the simulation model, of the simulation parameters and through trial-and-error attempts to an optimized solution. The ability to early see the first results from a multidimensional simulation space--thousands of simulations are run for a multidimensional variety of input parameters--and to quickly go back into the simulation and request more runs in particular parameter regions of interest significantly improves the prototyping process and provides a deeper understanding of the system behavior. The excellent results which we achieved for the common rail injection system strongly suggest that our approach has a great potential of being generalized to other, similar scenarios.

  17. Ectopic bone formation in rapidly fabricated acellular injectable dense collagen-Bioglass hybrid scaffolds via gel aspiration-ejection.

    PubMed

    Miri, Amir K; Muja, Naser; Kamranpour, Neysan O; Lepry, William C; Boccaccini, Aldo R; Clarke, Susan A; Nazhat, Showan N

    2016-04-01

    Gel aspiration-ejection (GAE) has recently been introduced as an effective technique for the rapid production of injectable dense collagen (IDC) gel scaffolds with tunable collagen fibrillar densities (CFDs) and microstructures. Herein, a GAE system was applied for the advanced production and delivery of IDC and IDC-Bioglass(®) (IDC-BG) hybrid gel scaffolds for potential bone tissue engineering applications. The efficacy of GAE in generating mineralizable IDC-BG gels (from an initial 75-25 collagen-BG ratio) produced through needle gauge numbers 8G (3.4 mm diameter and 6 wt% CFD) and 14G (1.6 mm diameter and 14 wt% CFD) was investigated. Second harmonic generation (SHG) imaging of as-made gels revealed an increase in collagen fibril alignment with needle gauge number. In vitro mineralization of IDC-BG gels was confirmed where carbonated hydroxyapatite was detected as early as day 1 in simulated body fluid, which progressively increased up to day 14. In vivo mineralization of, and host response to, acellular IDC and IDC-BG gel scaffolds were further investigated following subcutaneous injection in adult rats. Mineralization, neovascularization and cell infiltration into the scaffolds was enhanced by the addition of BG and at day 21 post injection, there was evidence of remodelling of granulation tissue into woven bone-like tissue in IDC-BG. SHG imaging of explanted scaffolds indicated collagen fibril remodelling through cell infiltration and mineralization over time. In sum, the results suggest that IDC-BG hybrid gels have osteoinductive properties and potentially offer a novel therapeutic approach for procedures requiring the injectable delivery of a malleable and dynamic bone graft that mineralizes under physiological conditions.

  18. Thermal analysis of injection beam dump of high-intensity rapid-cycling synchrotron in J-PARC

    NASA Astrophysics Data System (ADS)

    Kamiya, J.; Saha, P. K.; Yamamoto, K.; Kinsho, M.; Nihei, T.

    2017-10-01

    The beam dump at the beam injection area in the J-PARC 3-GeV rapid cycling synchrotron (RCS) accepts beams that pass through the charge exchange foil without ideal electron stripping during the multi-turn beam injection. The injection beam dump consists of the beam pipe, beam stopper, radiation shield, and cooling mechanism. The ideal beam power into the injection beam dump is 400 W in the case of design RCS extraction beam power of 1 MW with a healthy foil, which has 99.7 % charge stripping efficiency. On the other hand, as a radiation generator, the RCS is permitted to be operated with maximum average beam power of 4 kW into the injection beam dump based on the radiation shielding calculation, in consideration of lower charge stripping efficiency due to the foil deterioration. In this research, to evaluate the health of the RCS injection beam dump system from the perspective of the heat generation, a thermal analysis was performed based on the actual configuration with sufficiently large region, including the surrounding concrete and soil. The calculated temperature and heat flux density distribution showed the validity of the mesh spacing and model range. The calculation result showed that the dumped 4 kW beam causes the temperature to increase up to 330, 400, and 140 °C at the beam pipe, beam stopper, and radiation shield, respectively. Although these high temperatures induce stress in the constituent materials, the calculated stress values were lower than the ultimate tensile strength of each material. Transient temperature analysis of the beam stopper, which simulated the sudden break of the charge stripper foil, demonstrated that one bunched beam pulse with the maximum beam power does not lead to a serious rise in the temperature of the beam stopper. Furthermore, from the measured outgassing rate of stainless steel at high temperature, the rise in beam line pressure due to additive outgassing from the heated beam pipe was estimated to have a negligible

  19. A simple and rapid method for purification of triamcinolone acetonide suspension for intravitreal injection.

    PubMed

    Hernaez-Ortega, Maria C; Soto-Pedre, Enrique

    2004-01-01

    Purification of triamcinolone acetonide suspension is important to avoid the potential toxic effects of the vehicle. The aim of this article is to describe a simple and rapid technique to remove the vehicle, instead of the long procedure described in the literature. Triamcinolone acetonide suspension was sedimented by density gradient centrifugation. In a few minutes, this new technique yielded a clear supernatant that was easily replaced by a nontoxic sterile solution. More prolonged procedures may not be convenient for unplanned treatments and may also contribute to a greater chance for contamination of the triamcinolone acetonide suspension.

  20. Rapid tumoritropic accumulation of systemically injected plateloid particles and their biodistribution

    PubMed Central

    van de Ven, Anne L.; Kim, Pilhan; Haley, O’Hara; Fakhoury, Jean R.; Adriani, Giulia; Schmulen, Jeffrey; Moloney, Padraig; Hussain, Fazle; Ferrari, Mauro; Liu, Xuewu; Yun, Seok-Hyun; Decuzzi, Paolo

    2011-01-01

    Nanoparticles for cancer therapy and imaging are designed to accumulate in the diseased tissue by exploiting the Enhanced Permeability and Retention (EPR) effect. This limits their size to about 100 nm. Here, using intravital microscopy and elemental analysis, we compare the in vivo localization of particles with different geometries and demonstrate that plateloid particles preferentially accumulate within the tumor vasculature at unprecedented levels, independent of the EPR effect. In melanoma-bearing mice, 1000×400 nm plateloid particles adhered to the tumor vasculature at about 5% and 10% of the injected dose per gram organ (ID/g) for untargeted and RGD-targeted particles respectively, and exhibited the highest tumor-to-liver accumulation ratios (0.22 and 0.35). Smaller and larger plateloid particles, as well as cylindroid particles, were more extensively sequestered by the liver, spleen and lungs. Plateloid particles appeared well-suited for taking advantage of hydrodynamic forces and interfacial interactions required for efficient tumoritropic accumulation, even without using specific targeting ligands. PMID:22062689

  1. A Design Methodology for Rapid Implementation of Active Control Systems Across Lean Direct Injection Combustor Platforms

    NASA Technical Reports Server (NTRS)

    Baumann, William T.; Saunders, William R.; Vandsburger, Uri; Saus, Joseph (Technical Monitor)

    2003-01-01

    The VACCG team is comprised of engineers at Virginia Tech who specialize in the subject areas of combustion physics, chemical kinetics, dynamics and controls, and signal processing. Currently, the team's work on this NRA research grant is designed to determine key factors that influence combustion control performance through a blend of theoretical and experimental investigations targeting design and demonstration of active control for three different combustors. To validiate the accuracy of conclusions about control effectiveness, a sequence of experimental verifications on increasingly complex lean, direct injection combustors is underway. During the work period January 1, 2002 through October 15, 2002, work has focused on two different laboratory-scale combustors that allow access for a wide variety of measurements. As the grant work proceeds, one key goal will be to obtain certain knowledge about a particular combustor process using a minimum of sophisticated measurements, due to the practical limitations of measurements on full-scale combustors. In the second year, results obtained in the first year will be validated on test combustors to be identified in the first quarter of that year. In the third year, it is proposed to validate the results at more realistic pressure and power levels by utilizing the facilities at the Glenn Research Center.

  2. Injection to Rapid Diffusive Shock Acceleration at Perpendicular Shocks in Partially Ionized Plasmas

    NASA Astrophysics Data System (ADS)

    Ohira, Yutaka

    2016-08-01

    We present a three-dimensional hybrid simulation of a collisionless perpendicular shock in a partially ionized plasma for the first time. In this simulation, the shock velocity and upstream ionization fraction are v sh ≈ 1333 km s-1 and f i ˜ 0.5, which are typical values for isolated young supernova remnants (SNRs) in the interstellar medium. We confirm previous two-dimensional simulation results showing that downstream hydrogen atoms leak into the upstream region and are accelerated by the pickup process in the upstream region, and large magnetic field fluctuations are generated both in the upstream and downstream regions. In addition, we find that the magnetic field fluctuations have three-dimensional structures and the leaking hydrogen atoms are injected into the diffusive shock acceleration (DSA) at the perpendicular shock after the pickup process. The observed DSA can be interpreted as shock drift acceleration with scattering. In this simulation, particles are accelerated to v ˜ 100 v sh ˜ 0.3 c within ˜100 gyroperiods. The acceleration timescale is faster than that of DSA in parallel shocks. Our simulation results suggest that SNRs can accelerate cosmic rays to 1015.5 eV (the knee) during the Sedov phase.

  3. Measuring the QCD Gell Mann-Low Psi-Function

    SciTech Connect

    Pelaez, Jose R

    1999-06-14

    We present a general method for extracting the Gell Mann-Low logarithmic derivative of an effective charge of an observable directly from data as a mean for empirically verifying the universal terms of the QCD {beta}-function. Our method avoids the biases implicit in fitting to QCD-motivated forms as well as the interpolation errors introduced by constructing derivatives from discrete data. We also derive relations between moments of effective charges as new tests of perturbative QCD.

  4. Rapid flow injection method for the determination of sulfite in wine using the permanganate-luminol luminescence system.

    PubMed

    Navarrro, Mercedes Villar; Payán, María Ramos; López, Miguel Angel Bello; Fernández-Torres, Rut; Mochón, Manuel Callejón

    2010-10-15

    A simple, rapid and sensitive chemiluminescence method for the determination of sulfite has been developed by combining flow-injection analysis and its sensitizing effect on the known chemiluminescence emission produced by the oxidation of luminol in alkaline medium; in this work permanganate has been proposed as oxidizing reactive. The optimum conditions for the chemiluminescence emission were established. The chemiluminescence was proportional to the sulfite concentration over the range 1.6 × 10(-5) and 4.0 × 10(-4)mol L(-1). The detection limit was 4.7 × 10(-6)mol L(-1) of sulfite. The method has been satisfactorily used for the determination of free and bound sulfite in wines.

  5. Rapid analytical assessment of the mechanical perturbations induced by non-isothermal injection into a subsurface formation.

    NASA Astrophysics Data System (ADS)

    De Simone, Silvia; Carrera, Jesús; María Gómez Castro, Berta

    2016-04-01

    Fluid injection into geological formations is required for several engineering operations, e.g. geothermal energy production, hydrocarbon production and storage, CO2 storage, wastewater disposal, etc. Non-isothermal fluid injection causes alterations of the pressure and temperature fields, which affect the mechanical stability of the reservoir. This coupled thermo-hydro-mechanical behavior has become a matter of special interest because of public concern about induced seismicity. The response is complex and its evaluation often requires numerical modeling. Nevertheless, analytical solutions are useful in improving our understanding of interactions, identifying the controlling parameters, testing codes and in providing a rapid assessment of the system response to an alteration. We present an easy-to-use solution to the transient advection-conduction heat transfer problem for parallel and radial flow. The solution is then applied to derive analytical expressions for hydraulic and thermal driven displacements and stresses. The validity is verified by comparison with numerical simulations and yields fairly accurate results. The solution is then used to illustrate some features of the poroelastic and thermoelastic response and, in particular, the sensitivity to the external mechanical constraints and to the reservoir dimension.

  6. A study on the use of near-infrared spectroscopy for the rapid quantification of major compounds in Tanreqing injection

    NASA Astrophysics Data System (ADS)

    Li, Wenlong; Cheng, Zhiwei; Wang, Yuefei; Qu, Haibin

    2013-01-01

    In this paper we describe the strategy used in the development and validation of a near infrared spectroscopy method for the rapid determination of baicalin, chlorogenic acid, ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA), and the total solid contents (TSCs) in the Tanreqing injection. To increase the representativeness of calibration sample set, a concentrating-diluting method was adopted to artificially prepare samples. Partial least square regression (PLSR) was used to establish calibration models, with which the five quality indicators can be determined with satisfied accuracy and repeatability. In addition, the slope/bias (S/B) method was used for the models transfer between two different types of NIR instruments from the same manufacturer, which is contributing to enlarge the application range of the established models. With the presented method, a great deal of time, effort and money can be saved when large amounts of Tanreqing injection samples need to be analyzed in a relatively short period of time, which is of great significance to the traditional Chinese medicine (TCM) industries.

  7. Reversible gelling culture media for in-vitro cell culture in three-dimensional matrices

    DOEpatents

    An, Yuehuei H.; Mironov, Vladimir A.; Gutowska, Anna

    2000-01-01

    A gelling cell culture medium useful for forming a three dimensional matrix for cell culture in vitro is prepared by copolymerizing an acrylamide derivative with a hydrophilic comonomer to form a reversible (preferably thermally reversible) gelling linear random copolymer in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum gelling molecular weight cutoff, mixing the copolymer with an aqueous solvent to form a reversible gelling solution and adding a cell culture medium to the gelling solution to form the gelling cell culture medium. Cells such as chondrocytes or hepatocytes are added to the culture medium to form a seeded culture medium, and temperature of the medium is raised to gel the seeded culture medium and form a three dimensional matrix containing the cells. After propagating the cells in the matrix, the cells may be recovered by lowering the temperature to dissolve the matrix and centrifuging.

  8. Flow Injection Analysis with Electrochemical Detection for Rapid Identification of Platinum-Based Cytostatics and Platinum Chlorides in Water

    PubMed Central

    Kominkova, Marketa; Heger, Zbynek; Zitka, Ondrej; Kynicky, Jindrich; Pohanka, Miroslav; Beklova, Miroslava; Adam, Vojtech; Kizek, Rene

    2014-01-01

    Platinum-based cytostatics, such as cisplatin, carboplatin or oxaliplatin are widely used agents in the treatment of various types of tumors. Large amounts of these drugs are excreted through the urine of patients into wastewaters in unmetabolised forms. This phenomenon leads to increased amounts of platinum ions in the water environment. The impacts of these pollutants on the water ecosystem are not sufficiently investigated as well as their content in water sources. In order to facilitate the detection of various types of platinum, we have developed a new, rapid, screening flow injection analysis method with electrochemical detection (FIA-ED). Our method, based on monitoring of the changes in electrochemical behavior of analytes, maintained by various pH buffers (Britton-Robinson and phosphate buffer) and potential changes (1,000, 1,100 and 1,200 mV) offers rapid and cheap selective determination of platinum-based cytostatics and platinum chlorides, which can also be present as contaminants in water environments. PMID:24499878

  9. Flow injection analysis with electrochemical detection for rapid identification of platinum-based cytostatics and platinum chlorides in water.

    PubMed

    Kominkova, Marketa; Heger, Zbynek; Zitka, Ondrej; Kynicky, Jindrich; Pohanka, Miroslav; Beklova, Miroslava; Adam, Vojtech; Kizek, Rene

    2014-02-04

    Platinum-based cytostatics, such as cisplatin, carboplatin or oxaliplatin are widely used agents in the treatment of various types of tumors. Large amounts of these drugs are excreted through the urine of patients into wastewaters in unmetabolised forms. This phenomenon leads to increased amounts of platinum ions in the water environment. The impacts of these pollutants on the water ecosystem are not sufficiently investigated as well as their content in water sources. In order to facilitate the detection of various types of platinum, we have developed a new, rapid, screening flow injection analysis method with electrochemical detection (FIA-ED). Our method, based on monitoring of the changes in electrochemical behavior of analytes, maintained by various pH buffers (Britton-Robinson and phosphate buffer) and potential changes (1,000, 1,100 and 1,200 mV) offers rapid and cheap selective determination of platinum-based cytostatics and platinum chlorides, which can also be present as contaminants in water environments.

  10. A novel in-situ-gelling liquid suppository for site-targeting delivery of anti-colorectal cancer drugs.

    PubMed

    Lin, Hong-Ru; Tseng, Chao-Chih; Lin, Yiu-Jiuan; Ling, Ming-Hung

    2012-01-01

    In order to avoid anti-cancer drugs undergoing a first-pass effect and reduce their toxicity, and to solve conventional suppositories defects, we developed an in-situ-gelling and injectable Pluronic-poly(acrylic acid) (Pluronic-PAA) liquid suppository, which could gel fast in the physiological state and had suitable gel strength and bioadhesive force. The liquid suppositories were inserted into the rectum of rabbits without difficulty and leakage, and retained in the rectum for at least 6 h and while releasing the drug. The toxicity and cytotoxic tests indicated that Pluronic and PAA were non-toxic materials and could inhibit colon cancer cells when oxaliplatin was incorporated. C max and AUC0→12h values of oxaliplatin after rectal administration of a oxaliplatin suppository were higher than those for an oxaliplatin solution administered orally. These results suggest that an in-situ-gelling and injectable liquid suppository for humans can be further developed as a more convenient and effective rectal dosage form.

  11. Rapid detection of pesticides not amenable to multi-residue methods by flow injection-tandem mass spectrometry.

    PubMed

    Mol, Hans G J; van Dam, Ruud C J

    2014-11-01

    Flow injection combined with tandem mass spectrometry (MS/MS) was investigated for the rapid detection of highly polar pesticides that are not amenable to multi-residue methods because they do not partition into organic solvents and require dedicated chromatographic conditions. The pesticides included in this study were amitrole, chlormequat, cyromazine, daminozide, diquat, ethephon, fosetyl-Al, glufosinate, glyphosate and its metabolite aminomethylphosphonic acid, maleic hydrazide, mepiquat and paraquat. The composition of the flow-injection solvent was optimized to achieve maximum MS/MS sensitivity. Instrumental limits of detection varied between <0.05 and 1 pg. Fruit, vegetable, cereal, milk and kidney samples were extracted with water (1% formic acid in case of paraquat/diquat) and ten times diluted in either methanol/0.1% formic acid, methanol/0.1% ammonia or acetonitrile/0.1% ammonia, depending on the pesticide. The ion suppression observed depended strongly on both the matrix and the pesticide. This could be largely compensated for by matrix-matched calibration, but more accurate quantification was obtained by using isotopically labelled standards (commercially available for most of the pesticides studied). The method detection limits ranged from 0.02 mg/kg for chlormequat and mepiquat to 2 mg/kg for maleic hydrazide and were 0.05-0.2 mg/kg for most other pesticide/matrix combinations. This was sufficiently low to test compliance with EU maximum residue limits for many relevant pesticide/commodity combinations. The method substantially reduces the liquid chromatography-MS/MS capacity demand which for many laboratories is prohibitive for inclusion of these pesticides in their monitoring and surveillance programmes.

  12. Intravenously injected human apolipoprotein A-I rapidly enters the central nervous system via the choroid plexus.

    PubMed

    Stukas, Sophie; Robert, Jerome; Lee, Michael; Kulic, Iva; Carr, Michael; Tourigny, Katherine; Fan, Jianjia; Namjoshi, Dhananjay; Lemke, Kalistyne; DeValle, Nicole; Chan, Jeniffer; Wilson, Tammy; Wilkinson, Anna; Chapanian, Rafi; Kizhakkedathu, Jayachandran N; Cirrito, John R; Oda, Michael N; Wellington, Cheryl L

    2014-11-12

    Brain lipoprotein metabolism is dependent on lipoprotein particles that resemble plasma high-density lipoproteins but that contain apolipoprotein (apo) E rather than apoA-I as their primary protein component. Astrocytes and microglia secrete apoE but not apoA-I; however, apoA-I is detectable in both cerebrospinal fluid and brain tissue lysates. The route by which plasma apoA-I enters the central nervous system is unknown. Steady-state levels of murine apoA-I in cerebrospinal fluid and interstitial fluid are 0.664 and 0.120 μg/mL, respectively, whereas brain tissue apoA-I is ≈10% to 15% of its levels in liver. Recombinant, fluorescently tagged human apoA-I injected intravenously into mice localizes to the choroid plexus within 30 minutes and accumulates in a saturable, dose-dependent manner in the brain. Recombinant, fluorescently tagged human apoA-I accumulates in the brain for 2 hours, after which it is eliminated with a half-life of 10.3 hours. In vitro, human apoA-I is specifically bound, internalized, and transported across confluent monolayers of primary human choroid plexus epithelial cells and brain microvascular endothelial cells. Following intravenous injection, recombinant human apoA-I rapidly localizes predominantly to the choroid plexus. Because apoA-I mRNA is undetectable in murine brain, our results suggest that plasma apoA-I, which is secreted from the liver and intestine, gains access to the central nervous system primarily by crossing the blood-cerebrospinal fluid barrier via specific cellular mediated transport, although transport across the blood-brain barrier may also contribute to a lesser extent. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  13. A rapid screening procedure for drugs and poisons in gastric contents by direct injection-HPLC analysis.

    PubMed

    Politi, Lucia; Groppi, Angelo; Polettini, Aldo; Montagna, Maria

    2004-05-10

    A high performance liquid chromatographic method for toxicological drug screening of gastric content has been developed. The samples were diluted (1:3-1:30) in 0.01 N hydrochloric acid and injected into a reverse phase column for separation by gradient elution. Mobile phase consisted of solvent A (acetonitrile/water 90:10, 0.01 M sodium dodecylsulphate, 0.5% v/v glacial acetic acid) and solvent B (water/acetonitrile 90:10, 0.01 M sodium dodecylsulphate, 0.5% v/v glacial acetic acid); the gradient was programmed from 20 to 80% A in 30 min. The flow was kept constant at 1.5 ml/min. Two home-made internal standards, butyrylsalicylic acid and diacetyltubocurarine with retention times of 5.6 and 21.4 min, respectively, were used. Drugs are identified by matching their relative retention times and UV spectra (200-400 nm) with those contained in a home made library of more than 340 reference compounds (9 analgesics, 22 antidepressants, 30 antihistamines, 14 antihypertensives, 21 antirheumatics, 15 beta-blockers, 9 bronchodilators, 10 Ca antagonists, 14 diuretics, 26 neuroleptics, 25 tranquilizers, and other significant xenobiotic compounds). The fluorometric (FLD) emission spectrum (280-700 nm; excitation wavelength, 230 nm) was used as a further identification. At 50mg/l analyte concentrations, the injection of gastric content after dilution (1:3) produced S/N ratios in the range 8-140. The method is simple, rapid, rather inexpensive and proved to be a useful means of investigation if used in combination with GC-MS screening in blood. On the other hand, the system suffers from a relatively limited sensitivity for compounds with a low UV absorption and from interferences due to the presence in the matrix of some highly UV- and FL-responsive compounds (e.g. tryptophan).

  14. Intravenously Injected Human Apolipoprotein A‐I Rapidly Enters the Central Nervous System via the Choroid Plexus

    PubMed Central

    Stukas, Sophie; Robert, Jerome; Lee, Michael; Kulic, Iva; Carr, Michael; Tourigny, Katherine; Fan, Jianjia; Namjoshi, Dhananjay; Lemke, Kalistyne; DeValle, Nicole; Chan, Jeniffer; Wilson, Tammy; Wilkinson, Anna; Chapanian, Rafi; Kizhakkedathu, Jayachandran N.; Cirrito, John R.; Oda, Michael N.; Wellington, Cheryl L.

    2014-01-01

    Background Brain lipoprotein metabolism is dependent on lipoprotein particles that resemble plasma high‐density lipoproteins but that contain apolipoprotein (apo) E rather than apoA‐I as their primary protein component. Astrocytes and microglia secrete apoE but not apoA‐I; however, apoA‐I is detectable in both cerebrospinal fluid and brain tissue lysates. The route by which plasma apoA‐I enters the central nervous system is unknown. Methods and Results Steady‐state levels of murine apoA‐I in cerebrospinal fluid and interstitial fluid are 0.664 and 0.120 μg/mL, respectively, whereas brain tissue apoA‐I is ≈10% to 15% of its levels in liver. Recombinant, fluorescently tagged human apoA‐I injected intravenously into mice localizes to the choroid plexus within 30 minutes and accumulates in a saturable, dose‐dependent manner in the brain. Recombinant, fluorescently tagged human apoA‐I accumulates in the brain for 2 hours, after which it is eliminated with a half‐life of 10.3 hours. In vitro, human apoA‐I is specifically bound, internalized, and transported across confluent monolayers of primary human choroid plexus epithelial cells and brain microvascular endothelial cells. Conclusions Following intravenous injection, recombinant human apoA‐I rapidly localizes predominantly to the choroid plexus. Because apoA‐I mRNA is undetectable in murine brain, our results suggest that plasma apoA‐I, which is secreted from the liver and intestine, gains access to the central nervous system primarily by crossing the blood–cerebrospinal fluid barrier via specific cellular mediated transport, although transport across the blood–brain barrier may also contribute to a lesser extent. PMID:25392541

  15. Rheological properties of reversible thermo-setting in situ gelling solutions with the methylcellulose-polyethylene glycol-citric acid ternary system (2): Effects of various water-soluble polymers and salts on the gelling temperature.

    PubMed

    Shimokawa, Ken-ichi; Saegusa, Katsuhiko; Ishii, Fumiyoshi

    2009-11-01

    The influences of various salts and water-soluble polymers on the phase transition temperature of thermo-setting gels prepared by combining methylcellulose (MC)-sodium citrate (SC)-polyethylene glycol (PEG) at appropriate ratios (the MC-SC-PEG system) were investigated. Concerning cations, comparison of the phase transition temperature between SC and tripotassium citrate (PC) showed a rapid increase in the viscosity of SC between 20 degrees C and 25 degrees C and an increase in the viscosity of PC between 30 degrees C and 35 degrees C. Concerning the valency of anions, comparisons among SC, disodium tartrate dihydrate (ST), disodium maleate hemihydrates (SM), and sodium sulfate (SS) showed a rapid increase in the viscosity of trivalent SC between 20 degrees C and 25 degrees C and changes in the viscosity of the three bivalent sodium salts (ST, SM, and SS) at > or =30 degrees C. Thus the phase transition temperature decreased with an increase in the valency of anions. Subsequently, the influences of various water-soluble polymers on the gelling temperature were compared. Using polyvinylpyrrolidone (PVP) instead of PEG, the gelling temperature decreased with an increase in the PVP concentration even without the addition of SC. Unlike PVP, the addition of xanthan gum as a viscosity-increasing polysaccharide did not reduce the gelling temperature irrespective of its concentration. Temperature-associated changes in viscosity were observed at a fixed SC concentration with changes in the concentration of PVP or PEG. The gel phase transition temperature increased from 46 degrees C to 50 degrees C in gels not containing PVP or PEG. The viscosity did not differ between the addition of PVP or PEG at a low concentration and its absence. However, the viscosity clearly changed after the addition of each agent at a high concentration.

  16. Examination of gelling agents to produce acetaminophen jelly.

    PubMed

    Inoue, Yutaka; Iwazaki, Yuka; Onuki, Yoshinori; Funatani, Chiaki; Murata, Isamu; Kanamoto, Ikuo

    2015-01-01

    The current study used 3 types of carrageenan (denoted here as Car)-κ, ι, and λ-to prepare a jelly vehicle for acetaminophen (AAP), and then compared their usefulness as jelly vehicles. The rheological characteristics of each preparation were assessed and then drug elution from the preparation was assessed using dissolution testing. The behavior of each preparation when immersed in water was also examined using magnetic resonance imaging (MRI) in order to better understand the drug elution behaviour of each preparation. Viscoelasticity measurements revealed that 0.75 w/v%-ι-Car and 1.25 w/v%-λ-Car had viscoelasticity values equivalent to that of 0.5 w/v%-κ-Car. Dissolution testing of these 3 preparations indicated that 100% drug elution took 45 min with 0.5 w/v%-κ-Car while it took only 5 min with 0.75 w/v%-ι-Car and 1.25 w/v%-λ-Car. When deuterium oxide was added to κ-Car 0.5%, the MRI images darkened overall starting immediately after addition. The images revealed that the sample and deuterium oxide quickly mixed. In contrast, images revealed that deuterium oxide gradually penetrated κ-Car 1.0%. MRI images had uniform contrast, and deuterium oxide took 6 h or longer to penetrate the samples overall. These findings suggest that water is less apt to penetrate a jelly with an increased car concentration and a denser 3-dimensional network structure. Differences in the structure of car are said to result in better gelling, with κ having the best gelling characteristics, followed by ι and then λ. Thus, this paper discusses the role that vehicle gelling strength plays in the elution of acetaminophen.

  17. Peptide Inhibitor of Complement C1 (PIC1) Rapidly Inhibits Complement Activation after Intravascular Injection in Rats

    PubMed Central

    Sharp, Julia A.; Hair, Pamela S.; Pallera, Haree K.; Kumar, Parvathi S.; Mauriello, Clifford T.; Nyalwidhe, Julius O.; Phelps, Cody A.; Park, Dalnam; Thielens, Nicole M.; Pascal, Stephen M.; Chen, Waldon; Duffy, Diane M.; Lattanzio, Frank A.; Cunnion, Kenji M.; Krishna, Neel K.

    2015-01-01

    The complement system has been increasingly recognized to play a pivotal role in a variety of inflammatory and autoimmune diseases. Consequently, therapeutic modulators of the classical, lectin and alternative pathways of the complement system are currently in pre-clinical and clinical development. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement and is referred to as Peptide Inhibitor of Complement C1 (PIC1). In this study, we determined that the lead PIC1 variant demonstrates a salt-dependent binding to C1q, the initiator molecule of the classical pathway. Additionally, this peptide bound to the lectin pathway initiator molecule MBL as well as the ficolins H, M and L, suggesting a common mechanism of PIC1 inhibitory activity occurs via binding to the collagen-like tails of these collectin molecules. We further analyzed the effect of arginine and glutamic acid residue substitution on the complement inhibitory activity of our lead derivative in a hemolytic assay and found that the original sequence demonstrated superior inhibitory activity. To improve upon the solubility of the lead derivative, a pegylated, water soluble variant was developed, structurally characterized and demonstrated to inhibit complement activation in mouse plasma, as well as rat, non-human primate and human serum in vitro. After intravenous injection in rats, the pegylated derivative inhibited complement activation in the blood by 90% after 30 seconds, demonstrating extremely rapid function. Additionally, no adverse toxicological effects were observed in limited testing. Together these results show that PIC1 rapidly inhibits classical complement activation in vitro and in vivo and is functional for a variety of animal species, suggesting its utility in animal models of classical complement-mediated diseases. PMID:26196285

  18. Fabrication of catalytically active Au/Pt/Pd trimetallic nanoparticles by rapid injection of NaBH{sub 4}

    SciTech Connect

    Zhang, Haijun; Lu, Lilin; Cao, Yingnan; Du, Shuang; Cheng, Zhong; Zhang, Shaowei

    2014-01-01

    Graphical abstract: The synthesis and characterization of 2.0 nm-diameter Au/Pt/Pd nanoparticles are reported. The catalytic activity for glucose oxidation of the nanoparticles is several times higher than that of Au nanoparticles with nearly same size. - Highlights: • PVP-protected Au/Pt/Pd trimetallic nanoparticles (TNPs) of 2.0 nm in diameter were prepared. • The catalytic activity of TNPs is several times higher than that of Au nanoparticles. • Negatively charged Au atoms in the TNPs were confirmed by DFT calculation. - Abstract: Au/Pt/Pd trimetallic nanoparticles (TNPs) with an alloyed structure and an average diameter of about 2.0 nm were prepared via reducing the corresponding ions with rapidly injected NaBH{sub 4}, and characterized by UV–vis, TEM and HR-TEM. The catalytic activity of as-prepared TNPs for the aerobic glucose oxidation is several times higher than that of Au monometallic nanoparticles with about the same average size, which could be attributed to the catalytically active sites provided by the negatively charged Au atoms as a result of the electron donation from the neighboring Pd atoms. This was well supported by the electron density calculations based on the density functional theory.

  19. Rapid Identification and Assignation of the Active Ingredients in Fufang Banbianlian Injection Using HPLC-DAD-ESI-IT-TOF-MS.

    PubMed

    Li, Sensen; Lin, Zongtao; Jiang, Haixiu; Tong, Lingkun; Wang, Hong; Chen, Shizhong

    2016-08-01

    Fufang Banbianlian Injection (FBI) is a well-known traditional Chinese medicine formula composed of three herbal medicines. However, the systematic investigation on its chemical components has not been reported yet. In this study, a high-performance liquid chromatography combined with diode-array detector, and coupled to an electrospray ionization with ion-trap time-of-flight mass spectrometry (HPLC-DAD-ESI-IT-TOF-MS) method, was established for the identification of chemical profile in FBI. Sixty-six major constituents (14 phenolic acids, 14 iridoids, 20 flavonoids, 2 benzylideneacetone compounds, 3 phenylethanoid glycosides, 1 coumarin, 1 lignan, 3 nucleosides, 1 amino acids, 1 monosaccharides, 2 oligosaccharides, 3 alduronic acids and citric acid) were identified or tentatively characterized by comparing their retention times and MS spectra with those of standards or literature data. Finally, all constituents were further assigned in the individual herbs (InHs), although some of them were from multiple InHs. As a result, 11 compounds were from Lobelia chinensis Lour, 33 compounds were from Scutellaria barbata D. Don and 38 compounds were from Hedyotis diffusa Willd. In conclusion, the developed HPLC-DAD-ESI-IT-TOF-MS method is a rapid and efficient technique for analysis of FBI sample, and could be a valuable method for the further study on the quality control of the FBI.

  20. Rapid Qualitative Risk Assessment for Contaminant Leakage From Coal Seams During Underground Coal Gasification and CO2 Injection

    SciTech Connect

    Friedmann, S J

    2004-07-02

    One of the major risks associated with underground coal gasification is contamination of local aquifers with a variety of toxic compounds. It is likely that the rate, volume, extent, and concentrations of contaminant plumes will depend on the local permeability field near the point of gasification. This field depends heavily on the geological history of stratigraphic deposition and the specifics of stratigraphic succession. Some coals are thick and isolated, whereas others are thinner and more regionally expressed. Some coals are overlain by impermeable units, such as marine or lacustrine shales, whereas others are overlain by permeable zones associated with deltaic or fluvial successions. Rapid stratigraphic characterization of the succession provides first order information as to the general risk of contaminant escape, which provides a means of ranking coal contaminant risks by their depositional context. This risk categorization could also be used for ranking the relative risk of CO{sub 2} escape from injected coal seams. Further work is needed to verify accuracy and provide some quantification of risks.

  1. The containment of oil spills in porous media using xanthan/aluminum solutions, gelled by gaseous CO2 or by AlCl3 solutions.

    PubMed

    Gioia, Francesco; Ciriello, Pier Paolo

    2006-12-01

    The gelation in situ of polymers may be a method for temporarily containing organic solvents and other petroleum derived products, which may enter the subsurface. In order to create gels that are neither toxic to humans nor to the ecosystem, we have investigated on the use of the biopolymer xanthan gum with aluminum as a crosslinking agent. Firstly we have considered xanthan/sodium aluminate solutions, which upon preparation are strongly basic and do not gel. The gelation takes place in acid solutions so that Al(III) ions are released, and is instantaneous. Therefore, a special technique must be used for generating the gel structure in situ. The un-gelled solution must be injected and an acid must be added afterwards. We have investigated on the gelling reaction induced by gaseous carbon dioxide, which is an acid gas. The insufflation of CO(2) above the solution generates a layer of gel whose thickness progressively increases as CO(2) diffuses in the polymer solution. Secondly we have investigated on the use of aluminum chloride as the source of Al(III) ions. Also in this case, due to the full availability of Al(III) ions, the gelling reaction would be instantaneous. Therefore, the solution of AlCl(3) must be added on the top of the xanthan solution after its injection. For both gelling systems we have studied both theoretically and experimentally the rate of formation of the gel layer which progressively thickens after the insufflation of CO(2) or after the addition of the AlCl(3) solution.

  2. Thiolated silicone oil: synthesis, gelling and mucoadhesive properties.

    PubMed

    Partenhauser, Alexandra; Laffleur, Flavia; Rohrer, Julia; Bernkop-Schnürch, Andreas

    2015-04-01

    The aim of this study was the development of novel thiolated silicone oils and their evaluation with regard to gelling and mucoadhesive properties. A thiol coupling of 220 ± 14 and 127 ± 33 μmol/g polymer for 3-mercaptopropionic acid (MPA)- and cysteine-coupled silicone oil was determined, respectively. The dynamic viscosity of MPA-silicone raised significantly (p<0.000001) after oxidation with iodine to a maximum of 523-fold within 1h. During tensile studies, MPA-silicone showed both the highest results for total work of adhesion (TWA) and maximum detachment force (MDF) with a 3.8- and 3.4-fold increase, respectively, compared to the control. As far as the residence time on small intestinal mucosa is concerned, both silicone conjugates were detectable in almost the same quantities for up to 8h with 56.9 ± 3.3 and 47.8 ± 8.9% of the initially applied conjugated silicone oil. Thiolated silicone oils can be regarded superior in comparison to commonly used silicone oils due to a prolonged retention time in the small intestine as site of action. Gelling and mucoadhesive features are advantageous for antiflatulent as well as mucoprotective biomaterials. Thus, these novel thiomers seem promising for an upgrade of currently available products for the treatment of dyspepsia, reflux oesophagitis and even inflammatory bowel diseases such as ulcerative colitis or Crohn's disease.

  3. Progress in the development of gelling agents for improved culturability of microorganisms

    PubMed Central

    Das, Nabajit; Tripathi, Naveen; Basu, Srijoni; Bose, Chandra; Maitra, Susmit; Khurana, Sukant

    2015-01-01

    Gelling agents are required for formulating both solid and semisolid media, vital for the isolation of microorganisms. Gelatin was the first gelling agent to be discovered but it soon paved the way for agar, which has far superior material qualities. Source depletion, issues with polymerase-chain-reaction and inability to sustain extermophiles etc., necessitate the need of other gelling agents. Many new gelling agents, such as xantham gum, gellan gum, carrageenan, isubgol, and guar gum have been formulated, raising the hopes for the growth of previously unculturable microorganisms. We evaluate the progress in the development of gelling agents, with the hope that our synthesis would help accelerate research in the field. PMID:26257708

  4. Rapid determination of benzodiazepines, zolpidem and their metabolites in urine using direct injection liquid chromatography-tandem mass spectrometry.

    PubMed

    Jeong, Yu-Dong; Kim, Min Kyung; Suh, Sung Ill; In, Moon Kyo; Kim, Jin Young; Paeng, Ki-Jung

    2015-12-01

    Benzodiazepines and zolpidem are generally prescribed as sedative, hypnotics, anxiolytics or anticonvulsants. These drugs, however, are frequently misused in drug-facilitated crime. Therefore, a rapid and simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for identification and quantification of benzodiazepines, zolpidem and their metabolites in urine using deuterium labeled internal standards (IS). Urine samples (120 μL) mixed with 80 μL of the IS solution were centrifuged. An aliquot (5 μL) of the sample solution was directly injected into the LC-MS/MS system for analysis. The mobile phases consisted of water and acetonitrile containing 2mM ammonium trifluoroacetate and 0.2% acetic acid. The analytical column was a Zorbax SB-C18 (100 mm × 2.1 mm i.d., 3.5 μm, Agilent). The separation and detection of 18 analytes were achieved within 10 min. Calibration curves were linear over the concentration ranges of 0.5-20 ng/mL (zolpidem), 1.0-40 ng/mL (flurazepam and temazepam), 2.5-100 ng/mL (7-aminoclonazepam, 1-hydroxymidazolam, midazolam, flunitrazepam and alprazolam), 5.0-200 ng/mL (zolpidem phenyl-4-carboxylic acid, α-hydroxyalprazolam, oxazepam, nordiazepam, triazolam, diazepam and α-hydroxytriazolam), 10-400 ng/mL (lorazepam and desalkylflurazepam) and 10-100 ng/mL (N-desmethylflunitrazepam) with the coefficients of determination (r(2)) above 0.9971. The dilution integrity of the analytes was examined for supplementation of short linear range. Dilution precision and accuracy were tested using two, four and ten-folds dilutions and they ranged from 3.7 to 14.4% and -12.8 to 12.5%, respectively. The process efficiency for this method was 63.0-104.6%. Intra- and inter-day precisions were less than 11.8% and 9.1%, while intra- and inter-day accuracies were less than -10.0 to 8.2%, respectively. The lower limits of quantification were lower than 10 ng/mL for each analyte. The applicability of the developed method was successfully

  5. CT-Guided Thrombin Injection to Control Rapid Expansion of Ascending Aortic False Aneurysm 15 Months After Bentall-Bono Operation

    SciTech Connect

    Perek, Bartlomiej Urbanowicz, Tomasz; Zabicki, Bartosz; Puslecki, Mateusz; Juszkat, Robert; Jemielity, Marek

    2011-02-15

    We report a case of 57-year-old man treated emergently with CT-guided local thrombin injection as the first, life-saving step for control rapid expansion of the aortic pseudoaneurysm. Fifteen months earlier, he was operated on for ascending aortic true aneurysm and coronary artery disease. Upon admission, he had an anterior thoracic wall pulsatile tumor. Due to critical status, definite surgery was postponed and thrombin was injected close to the origin of pseudoaneurysm. It controlled successfully, bleeding from the ascending aorta and enabled the patient to survive the acute phase.

  6. In situ-Gelling, Erodible N-Isopropylacrylamide Copolymers

    PubMed Central

    Lee, Bae Hoon; Vernon, Brent

    2005-01-01

    Summary Copolymers of N-isopropylacrylamide, 2-hydroxyethyl methacryl lactate and acrylic acid were prepared with varying mole ratios of monomers to develop copolymers with gelation properties above a certain concentration for a bioerodible, in-situ gelling material. The copolymers formed gels in situ under physiological condition. The gelation temperature of the copolymers decreased as the HEMA-lactate content of the copolymers increased due to the hydrophobicity of HEMA-lactate, and increased as the AAc content increased due to the hydrophilicity of AAc. The gels redissolve at 37 °C as their LCSTs increase above 37°C due to the hydrolysis of the HEMA-lactate pendant groups. PMID:15997439

  7. Gelled colloidal crystals as tunable optical filters for spectrophotometers

    NASA Astrophysics Data System (ADS)

    Sugao, Yukihiro; Onda, Sachiko; Toyotama, Akiko; Takiguchi, Yoshihiro; Sawada, Tsutomu; Hara, Shigeo; Nishikawa, Suguru; Yamanaka, Junpei

    2016-08-01

    We examined the performance of charged colloidal crystals immobilized in a polymer gel as tunable optical filters. The colloidal crystals of charged silica particles (particle diameter = 121 nm; particle concentration = 3.5 vol %; and Bragg wavelength λB = 630-720 nm) were produced by unidirectional crystallization under a temperature gradient. Photocurable gelation reagents were dissolved in the sample beforehand; this enabled gel immobilization of the crystals under ultraviolet illumination. The crystals had dimensions of more than 25 mm2 in area and 1 mm in thickness, and spatial λB variations of less than 1%. Upon mechanical compression, λB values shifted linearly and reversibly over almost the entire visible spectrum. Using the gelled crystals as tunable optical filters, we measured the transmittance spectra of various samples and found them to be in close agreement with those determined using a spectrophotometer equipped with optical gratings.

  8. A Novel Pectin Material: Extraction, Characterization and Gelling Properties

    PubMed Central

    Urias-Orona, Vania; Rascón-Chu, Agustin; Lizardi-Mendoza, Jaime; Carvajal-Millán, Elizabeth; Gardea, Alfonso A.; Ramírez-Wong, Benjamín

    2010-01-01

    A novel pectin was acid extracted from chickpea husk (CHP). CHP presented a 67% (w/w) of galacturonic acid, an intrinsic viscosity of 374 mL/g and a viscosimetric molecular weight of 110 kDa. Fourier transform infrared spectroscopy spectrum of CHP indicated a degree of esterification of about 10%. The CHP-calcium system formed ionic gels with a storage (G′) modulus of 40 Pa and gel set time (G′ > G″) of 3 min at 1% (w/v), and a G′ of 131 Pa and gel set time of 1 min at 2% (w/v). The G′ of CHP gels was not greatly affected by temperature. The results attained suggest that chickpea husk can be a potential source of a gelling pectin material. PMID:21152294

  9. Thiolated silicone oil: Synthesis, gelling and mucoadhesive properties

    PubMed Central

    Partenhauser, Alexandra; Laffleur, Flavia; Rohrer, Julia; Bernkop-Schnürch, Andreas

    2015-01-01

    The aim of this study was the development of novel thiolated silicone oils and their evaluation with regard to gelling and mucoadhesive properties. A thiol coupling of 220 ± 14 and 127 ± 33 μmol/g polymer for 3-mercaptopropionic acid (MPA)- and cysteine-coupled silicone oil was determined, respectively. The dynamic viscosity of MPA–silicone raised significantly (p < 0.000001) after oxidation with iodine to a maximum of 523-fold within 1 h. During tensile studies, MPA–silicone showed both the highest results for total work of adhesion (TWA) and maximum detachment force (MDF) with a 3.8- and 3.4-fold increase, respectively, compared to the control. As far as the residence time on small intestinal mucosa is concerned, both silicone conjugates were detectable in almost the same quantities for up to 8 h with 56.9 ± 3.3 and 47.8 ± 8.9% of the initially applied conjugated silicone oil. Thiolated silicone oils can be regarded superior in comparison to commonly used silicone oils due to a prolonged retention time in the small intestine as site of action. Gelling and mucoadhesive features are advantageous for antiflatulent as well as mucoprotective biomaterials. Thus, these novel thiomers seem promising for an upgrade of currently available products for the treatment of dyspepsia, reflux oesophagitis and even inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease. PMID:25660565

  10. Biodegradable, Phosphate-containing, Dual-Gelling Macromers for Cellular Delivery in Bone Tissue Engineering

    PubMed Central

    Watson, Brendan M.; Vo, Tiffany N.; Tatara, Alexander M.; Shah, Sarita R.; Scott, David W.; Engel, Paul S.; Mikos, Antonios G.

    2015-01-01

    Injectable, biodegradable, dual-gelling macromer solutions were used to encapsulate mesenchymal stem cells (MSCs) within stable hydrogels when elevated to physiologic temperature. Pendant phosphate groups were incorporated in the N-isopropyl acrylamide-based macromers to improve biointegration and facilitate hydrogel degradation. The MSCs were shown to survive the encapsulation process, and live cells were detected within the hydrogels for up to 28 days in vitro. Cell-laden hydrogels were shown to undergo significant mineralization in osteogenic medium. Cell-laden and acellular hydrogels were implanted into a critical-size rat cranial defect for 4 and 12 weeks. Both cell-laden and acellular hydrogels were shown to degrade in vivo and help to facilitate bone growth into the defect. Improved bone bridging of the defect was seen with the incorporation of cells, as well as with higher phosphate content of the macromer. Furthermore, direct bone-to-hydrogel contact was observed in the majority of implants, which is not commonly seen in this model. The ability of these macromers to deliver stem cells while forming in situ and subsequently degrade while facilitating bone ingrowth into the defect makes this class of macromers a promising material for craniofacial bone tissue engineering. PMID:26232878

  11. Biodegradable, phosphate-containing, dual-gelling macromers for cellular delivery in bone tissue engineering.

    PubMed

    Watson, Brendan M; Vo, Tiffany N; Tatara, Alexander M; Shah, Sarita R; Scott, David W; Engel, Paul S; Mikos, Antonios G

    2015-10-01

    Injectable, biodegradable, dual-gelling macromer solutions were used to encapsulate mesenchymal stem cells (MSCs) within stable hydrogels when elevated to physiologic temperature. Pendant phosphate groups were incorporated in the N-isopropyl acrylamide-based macromers to improve biointegration and facilitate hydrogel degradation. The MSCs were shown to survive the encapsulation process, and live cells were detected within the hydrogels for up to 28 days in vitro. Cell-laden hydrogels were shown to undergo significant mineralization in osteogenic medium. Cell-laden and acellular hydrogels were implanted into a critical-size rat cranial defect for 4 and 12 weeks. Both cell-laden and acellular hydrogels were shown to degrade in vivo and help to facilitate bone growth into the defect. Improved bone bridging of the defect was seen with the incorporation of cells, as well as with higher phosphate content of the macromer. Furthermore, direct bone-to-hydrogel contact was observed in the majority of implants, which is not commonly seen in this model. The ability of these macromers to deliver stem cells while forming in situ and subsequently degrade while facilitating bone ingrowth into the defect makes this class of macromers a promising material for craniofacial bone tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Sodium dodecyl sulfate-induced rapid gelation of silk fibroin.

    PubMed

    Wu, Xilong; Hou, Jing; Li, Mingzhong; Wang, Jiangnan; Kaplan, David L; Lu, Shenzhou

    2012-07-01

    The in situ formation of injectable silk fibroin (SF) hydrogels have potential advantages over various other biomaterials due to the minimal invasiveness during application. Biomaterials need to gel rapidly under physiological conditions after injection. In the current paper, a novel way to accelerate SF gelation using an anionic surfactant, sodium dodecyl sulfate (SDS), as a gelling agent is reported. The mechanism of SDS-induced rapid gelation was determined. At low surfactant concentrations, hydrophobic interactions among the SF chains played a dominant role in the association, leading to decreased gelation time. At higher concentrations of surfactant, electrostatic repulsive forces among micellar aggregates gradually became dominant and gelation was hindered. Gel formation involves the connection of clusters formed by the accumulation of nanoparticles. This process is accompanied by the rapid formation of β-sheet structures due to hydrophobic and electrostatic interactions. It is expected that the silk hydrogel with short gelation time will be used as an injectable hydrogel in drug delivery or cartilage tissue engineering.

  13. A rapid and convenient technique for measuring the rate of protein synthesis in tissues by injection of [3H]phenylalanine.

    PubMed Central

    Garlick, P J; McNurlan, M A; Preedy, V R

    1980-01-01

    A rapid procedure for measuring the specific radioactivity of phenylalanine in tissues was developed. This facilitates the accurate determination of rates of protein synthesis in a wide range of tissues by injection of 150 mumol of L-[4-(3)H]phenylalanine/100 g body wt. The large dose of amino acid results in a rapid rise in specific radioactivity of free phenylalanine in tissues to values close to that in plasma, followed by a slow but linear fall. This enables the rate of protein synthesis to be calculated from measurements of the specific radioactivity of free and protein-bound phenylalanine in tissues during a 10 min period after injection of radioisotope. PMID:6786283

  14. Injectable hydrogels as unique biomedical materials.

    PubMed

    Yu, Lin; Ding, Jiandong

    2008-08-01

    A concentrated fish soup could be gelled in the winter and re-solled upon heating. In contrast, some synthetic copolymers exhibit an inverse sol-gel transition with spontaneous physical gelation upon heating instead of cooling. If the transition in water takes place below the body temperature and the chemicals are biocompatible and biodegradable, such gelling behavior makes the associated physical gels injectable biomaterials with unique applications in drug delivery and tissue engineering etc. Various therapeutic agents or cells can be entrapped in situ and form a depot merely by a syringe injection of their aqueous solutions at target sites with minimal invasiveness and pain. This tutorial review summarizes and comments on this soft matter, especially thermogelling poly(ethylene glycol)-(biodegradable polyester) block copolymers. The main types of injectable hydrogels are also briefly introduced, including both physical gels and chemical gels.

  15. Accessing gelling ability of vegetable proteins using rheological and fluorescence techniques.

    PubMed

    Batista, Ana Paula; Portugal, Carla A M; Sousa, Isabel; Crespo, João G; Raymundo, Anabela

    2005-08-01

    This work aims to present a comprehensive study about the macroscopic characteristics of globular vegetable proteins, in terms of their gelling ability, by understanding their molecular behaviour, when submitted to a thermal gelling process. The gels of soy, pea and lupin proteins were characterized by rheological techniques. Gelation kinetics, mechanical spectra, as well as the texture of these gels were analyzed and compared. Additionally, capillary viscometry, steady-state fluorescence and fluorescence anisotropy were used to monitor the structural changes induced by the thermal denaturation, which constitutes the main condition for the formation of a gel structure. Based on these techniques it was possible to establish a relationship between the gelling ability of each protein isolate and their structural resistance to thermal unfolding, enabling us to explain the weakest and the strongest gelling ability observed for lupin and soy proteins isolates, respectively.

  16. Cryogenic Gellant and Fuel Formulation for Metallized Gelled Propellants: Hydrocarbons and Hydrogen with Aluminum

    NASA Technical Reports Server (NTRS)

    Wong, Wing; Starkovich, John; Adams, Scott; Palaszewski, Bryan; Davison, William; Burt, William; Thridandam, Hareesh; Hu-Peng, Hsiao; Santy, Myrrl J.

    1994-01-01

    An experimental program to determine the viability of nanoparticulate gellant materials for gelled hydrocarbons and gelled liquid hydrogen was conducted. The gellants included alkoxides (BTMSE and BTMSH) and silica-based materials. Hexane, ethane, propane and hydrogen were gelled with the newly-formulated materials and their rheological properties were determined: shear stress versus shear rate and their attendant viscosities. Metallized hexane with aluminum particles was also rheologically characterized. The propellant and gellant formulations were selected for the very high surface area and relatively-high energy content of the gellants. These new gellants can therefore improve rocket engine specific impulse over that obtained with traditional cryogenic-fuel gellant materials silicon dioxide, frozen methane, or frozen ethane particles. Significant reductions in the total mass of the gellant were enabled in the fuels. In gelled liquid hydrogen, the total mass of gellant was reduced from 10-40 wt percent of frozen hydrocarbon particles to less that 8 wt percent with the alkoxide.

  17. A dry powder formulation from silk fibroin microspheres as a topical auto-gelling device.

    PubMed

    Faragò, Silvio; Lucconi, Giulia; Perteghella, Sara; Vigani, Barbara; Tripodo, Giuseppe; Sorrenti, Milena; Catenacci, Laura; Boschi, Alessandra; Faustini, Massimo; Vigo, Daniele; Chlapanidas, Theodora; Marazzi, Mario; Torre, Maria Luisa

    2016-01-01

    With the aim of establishing the formulation of a new hydrophilic auto-gelling medical device for biomedical applications, fibroin-based microspheres were prepared. The proposed microspheres were produced by a cost-effective and industrially scalable technique, such as the spray-drying. Spray-dried silk fibroin microspheres were obtained and the effects of different hydrophilic polymer on the process yield, microsphere morphology and conformation transition of fibroin were evaluated. The final auto-gelling formulations were obtained by adding calcium gluconate (as a calcium source for alginate crosslinking) to the prepared microspheres and tested by an in vitro gelling test. This study showed that the combination of fibroin with sodium alginate and poloxamer produced the most promising auto-gelling formulation for specific biomedical applications, such as the treatment of pressure ulcers.

  18. Antioxidant Gallic Acid-Functionalized Biodegradable in Situ Gelling Copolymers for Cytoprotective Antiglaucoma Drug Delivery Systems.

    PubMed

    Lai, Jui-Yang; Luo, Li-Jyuan

    2015-09-14

    In clinical ophthalmology, oxidative stress has been proposed as the initiating cause of ocular hypertension, which is one of the risk factors for glaucomatous damage and disease progression. In an attempt to improve the therapeutic efficacy of intracamerally administered pilocarpine, herein, a cytoprotective antiglaucoma drug delivery system composed of antioxidant gallic acid (GA)-functionalized gelatin-g-poly(N-isopropylacrylamide) (GN) biodegradable in situ gelling copolymer was developed for the first time. Analyses by UV-vis and Fourier transform infrared spectroscopies showed the formation of biopolymer-antioxidant covalent linkages in GNGA structures through a radical reaction in the presence of water-soluble redox initiators. The synthesized GNGA polymers with strong free radical scavenging effectiveness exhibited appropriate phase transition temperature and degradation rate as injectable bioerodible depots for minimally invasive pilocarpine delivery to the ocular anterior chamber. During the 2-week in vitro study, the sustained releases of sufficient amounts of pilocarpine for a therapeutic action in alleviating ocular hypertension could be achieved under physiological conditions. Results of cell viability, intracellular reactive oxygen species level, and intracellular calcium concentration indicated that the incorporation of antioxidant GA into GN structure can enhance cytoprotective effects of carrier materials against hydrogen peroxide-induced oxidative stress in lens epithelial cultures. Effective pharmacological responses (i.e., reduction of intraocular pressure and preservation of corneal endothelial cell morphology and density) in rabbits receiving intracameral GNGA injections containing pilocarpine were evidenced by clinical observations. The findings of in vivo studies also support the hypothesis that the GNGA carriers are more advantageous over their GN counterparts for the improvement of total antioxidant status in glaucomatous eyes with

  19. Metallized Gelled Propellants: Oxygen/RP-1/aluminum Rocket Combustion Experiments

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan; Zakany, James S.

    1995-01-01

    A series of combustion experiments were conducted to measure the specific impulse, Cstar-, and specific-impulse efficiencies of a rocket engine using metallized gelled liquid propellants. These experiments used a small 20- to 40-1bf (89- to 178-N) thrust, modular engine consisting of an injector, igniter, chamber and nozzle. The fuels used were traditional liquid RP-1 and gelled RP-1 with 0-, 5-, and 55-wt% loadings of aluminum and gaseous oxygen was the oxidizer. Ten different injectors were used during the testing: 6 for the baseline 02/RP-1 tests and 4 for the gelled fuel tests which covered a wide range of mixture ratios. At the peak of the Isp versus oxidizer-to-fuel ratio (O/F) data, a range of 93 to 99% Cstar efficiency was reached with ungelled 02/RP-1. A Cstar efficiency range of 75 to 99% was obtained with gelled RP-l (0-wt% RP-1/Al) while the metallized 5-wt% RP-1/Al delivered a Cstar efficiency of 94 to 99% at the peak Isp in the O/F range tested. An 88 to 99% Cstar efficiency was obtained at the peak Isp of the gelled RP1/Al with 55-wt% Al. Specific impulse efficiencies for the 55-wt% RP-1/Al of 67%-83% were obtained at a 2.4:1 expansion ratio. Injector erosion was evident with the 55-wt% testing, while there was little or no erosion seen with the gelled RP-1 with 0- and 5-wt% Al. A protective layer of gelled fuel formed in the firings that minimized the damage to the rocket injector face. This effect may provide a useful technique for engine cooling. These experiments represent a first step in characterizing the performance of and operational issues with gelled RP-1 fuels.

  20. Rapid sedation induced by fentanyl combined with propofol via an intrathecal chemotherapy injection for leukemia in children.

    PubMed

    Tian, X; Yang, Y-H; Wei, H-Y; Lao, J-Q; Wang, H-P; Tian, Y-Y

    2015-04-17

    This study explored the sedative and analgesic effects of fentanyl combined with propofol via an intrathecal chemotherapy injection for acute leukemia (acute lymphocytic leukemia or acute myelocytic leukemia) among children, to relieve pain and difficulty during intrathecal injection, improve treatment compliance, increase the success rate of single puncture, and reduce procedure failure, with the aim of developing a painless procedure for children with acute leukemia. Fifty person-times received fentanyl combined with propofol via an intrathecal chemotherapy injection among the hospitalized children with leukemia. The patients' cooperation with the procedure, response to the medication, dosages of fentanyl and propofol, reaction to the procedures, wake-up time, and changes in oxygen saturation (SpO2), heart rate (HR), respiration, and blood pressure (BP) before, during, and after the procedures were observed. The doctors who performed the procedures assessed the quality of sedation and analgesia. In the treatment group, the patients were quiet during the lumbar puncture and intrathecal injection, showing good sedation and analgesia. HR and respiration decreased slightly. There were no changes in SpO2 and BP. No obvious respiratory depression occurred with proper dosages. Only a few patients showed stertorous respiration, which stopped soon after the procedures. In the control group, the patients were agitated, crying, and not cooperative before and during the procedures, which made the procedures very difficult. During intrathecal injection, pain obviously reduced and the success rate of single lumbar puncture increased. It is safe and effective to apply fentanyl combined with propofol for sedation and analgesia.

  1. Rapid sequential injections of hyperpolarized [1-¹³C]pyruvate in vivo using a sub-kelvin, multi-sample DNP polarizer.

    PubMed

    Hu, Simon; Larson, Peder E Z; Vancriekinge, Mark; Leach, Andrew M; Park, Ilwoo; Leon, Christine; Zhou, Jenny; Shin, Peter J; Reed, Galen; Keselman, Paul; von Morze, Cornelius; Yoshihara, Hikari; Bok, Robert A; Nelson, Sarah J; Kurhanewicz, John; Vigneron, Daniel B

    2013-05-01

    The development of hyperpolarized technology utilizing dynamic nuclear polarization (DNP) has enabled the rapid measurement of (13)C metabolism in vivo with very high SNR. However, with traditional DNP equipment, consecutive injections of a hyperpolarized compound in an animal have been subject to a practical minimum time between injections governed by the polarization build-up time, which is on the order of an hour for [1-(13)C]pyruvate. This has precluded the monitoring of metabolic changes occurring on a faster time scale. In this study, we demonstrated the ability to acquire in vivo dynamic magnetic resonance spectroscopy (MRS) and 3D magnetic resonance spectroscopic imaging (MRSI) data in normal rats with a 5 min interval between injections of hyperpolarized [1-(13)C]pyruvate using a prototype, sub-Kelvin dynamic nuclear polarizer with the capability to simultaneously polarize up to 4 samples and dissolve them in rapid succession. There were minimal perturbations in the hyperpolarized spectra as a result of the multiple injections, suggesting that such an approach would not confound the investigation of metabolism occurring on this time scale. As an initial demonstration of the application of this technology and approach for monitoring rapid changes in metabolism as a result of a physiological intervention, we investigated the pharmacodynamics of the anti-cancer agent dichloroacetate (DCA), collecting hyperpolarized data before administration of DCA, 1 min after administration, and 6 min after administration. Dramatic increases in (13)C-bicarbonate were detected just 1 min (as well as 6 min) after DCA administration.

  2. Sustained ophthalmic delivery of ofloxacin from an ion-activated in situ gelling system.

    PubMed

    Abraham, Sindhu; Furtado, Sharon; Bharath, S; Basavaraj, B V; Deveswaran, R; Madhavan, V

    2009-04-01

    The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid pre-corneal elimination of the drug may be overcome by the use of in situ gel forming systems that are instilled as drops into the eye and then undergo a sol-gel transition in the cul-de-sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antibacterial agent ofloxacin, based on the concept of ion-activated in situ gelation. Sodium alginate was used as the gelling agent in combination with HPC (Hydroxy Propyl Cellulose) that acted as a viscosity-enhancing agent. In vitro release studies indicated that the alginate/HPC solution retained the drug better than the alginate or HPC solutions alone. The formulations were therapeutically efficacious, sterile, stable and provided sustained release of the drug over a period of time. These results demonstrate that the developed system is an alternative to conventional ophthalmic drops, patient compliance, industrially oriented and economical.

  3. A multicentred cohort evaluation of a chitosan gelling fibre dressing.

    PubMed

    Mason, Sue; Clarke, Caroline

    A multicentre cohort evaluation was undertaken by 15 clinicans in 11 centres across Staffordshire community care on chitosan gelling fibre dressing (Kytocel(®)). The aim of this evaluation was to examine whether the new fibre dressing improved healing outcomes for patients with chronic non-healing wounds of 6 weeks or more, observations were made regarding tissue type, fluid handling, haemostasis in bleeding friable wounds and increased granulation. Quality of life observations regarding leaking, strikethrough, pain, wear time and malodour were observed over a 4-week period or until healed. A total of 18 patients took part; 13 women and 5 men, with a mean age of 60.7 years. Fifteen (83%) had wounds in excess of 12 weeks and nine (50%) received care within wound clinics compared to home visits. Eleven (61%) patients' wounds healed within 4 weeks. A number of quality-of-life issues were addressed successfully, namely reduction in malodour and fluid handling. Sixteen (89%) rated the dressing's overall performance as very good to good.

  4. Rapid Quantitation of Ascorbic and Folic Acids in SRM 3280 Multivitamin/Multielement Tablets using Flow-Injection Tandem Mass Spectrometry

    SciTech Connect

    Bhandari, Deepak; Kertesz, Vilmos; Van Berkel, Gary J

    2013-01-01

    RATIONALE: Ascorbic acid (AA) and folic acid (FA) are water-soluble vitamins and are usually fortified in food and dietary supplements. For the safety of human health, proper intake of these vitamins is recommended. Improvement in the analysis time required for the quantitative determination of these vitamins in food and nutritional formulations is desired. METHODS: A simple and fast (~5 min) in-tube sample preparation was performed, independently for FA and AA, by mixing extraction solvent with a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Quantitative detection was achieved by flow-injection (1 L injection volume) electrospray ionization tandem mass spectrometry (ESI-MS/MS) in negative ion mode using the method of standard addition. RESULTS: Method of standard addition was employed for the quantitative estimation of each vitamin in a sample extract. At least 2 spiked and 1 non-spiked sample extract were injected in triplicate for each quantitative analysis. Given an injection-to-injection interval of approximately 2 min, about 18 min was required to complete the quantitative estimation of each vitamin. The concentration values obtained for the respective vitamins in the standard reference material (SRM) 3280 using this approach were within the statistical range of the certified values provided in the NIST Certificate of Analysis. The estimated limit of detections of FA and AA were 13 and 5.9 ng/g, respectively. CONCLUSIONS: Flow-injection ESI-MS/MS was successfully applied for the rapid quantitation of FA and AA in SRM 3280 multivitamin/multielement tablets.

  5. Evaluation of flow-injection tandem mass spectrometry for rapid and high-throughput quantitative determination of B vitamins in nutritional supplements.

    PubMed

    Bhandari, Deepak; Van Berkel, Gary J

    2012-08-29

    The use of flow-injection electrospray ionization tandem mass spectrometry for rapid and high-throughput mass spectral analysis of selected B vitamins, viz., B1, B2, B3, B5, and B6, in nutritional formulations was demonstrated. A simple and rapid (~5 min) in-tube sample preparation was performed. Automated flow injection introduced 1 μL of the extracts directly into the mass spectrometer ion source without chromatographic separation. Sample-to-sample analysis time was 60 s. Quantitative capabilities of the flow-injection analysis were tested using the method of standard additions and SRM 3280. The quantity determined for each B vitamin in SRM 3280 was within the statistical range provided for the respective certified values. This approach was also applied to two different commercial vitamin supplement tablets and proved to be successful in the quantification of the selected B vitamins, as evidenced by an agreement with the label values and the results obtained using isotope dilution liquid chromatography/mass spectrometry.

  6. Evaluation of Flow-Injection Tandem Mass Spectrometry for Rapid and High-Throughput Quantitative Determination of B-Vitamins in Nutritional Supplements

    SciTech Connect

    Bhandari, Deepak; Van Berkel, Gary J

    2012-01-01

    The use of flow-injection electrospray ionization tandem mass spectrometry for rapid and high-throughput mass spectral analysis of selected B-vitamins, viz. B1, B2, B3, B5, and B6, in nutritional formulations was demonstrated. A simple and rapid (~5 min) in-tube sample preparation was performed by adding extraction solvent to a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Automated flow injection introduced 1 L of the extracts directly into the mass spectrometer ion source without chromatographic separation. Sample-to-sample analysis time was 60 s representing significant improvement over conventional liquid chromatography approaches which typically require 25-45 min, and often require more significant sample preparation procedures. Quantitative capabilities of the flow-injection analysis were tested using the method of standard additions and NIST standard reference material (SRM 3280) multivitamin/multielement tablets. The quantity determined for each B-vitamin in SRM 3280 was within the statistical range provided for the respective certified values. The same sample preparation and analysis approach was also applied to two different commercial vitamin supplement tablets and proved to be successful in the quantification of the selected B-vitamins as evidenced by an agreement with the labels values and the results obtained using isotope dilution liquid chromatography/mass spectrometry.

  7. Quasi-flow injection analysis for rapid determination of caffeine in tea using the sample pre-treatment method with a cartridge column filled with polyvinylpolypyrrolidone.

    PubMed

    Yamauchi, Yuji; Nakamura, Akiko; Kohno, Iho; Hatanaka, Kirara; Kitai, Miki; Tanimoto, Tsuyoshi

    2008-01-04

    The sample pre-treatment method using a polyvinylpolypyrrolidone (PVPP) cartridge column combined with a quasi-flow injection analysis (quasi-FIA) system realized the rapid determination of caffeine in three types of tea, green, oolong and black tea. The measurement time for each tea sample pre-treated using a PVPP cartridge column was shortened to 20s. In the present system, the limits of detection and quantification were 0.3 microM (1.5 pmol injected) and 0.7 microM (3.5 pmol injected), respectively, and a linear calibration curve was afforded up to 800 microM (4 nmol injected). Within-run precision of analysis of standard solutions of 10 and 100 microM caffeine was 0.11 and 0.16% (n=6), respectively. Between-run precision of analysis of the same solutions over 6 days was 0.78 and 0.74% (n=6), respectively. Comparison with the conventional HPLC method indicated that the present quasi-FIA method using sample pre-treatment with a PVPP cartridge column was useful for the simple and precise determination of caffeine in green, oolong and black tea samples.

  8. Rapid and sensitive determination of benzaldehyde arising from benzyl alcohol used as preservative in an injectable formulation solution using dispersive liquid-liquid microextraction followed by gas chromatography.

    PubMed

    Mashayekhi, Hossein Ali; Rezaee, Mohammad; Garmaroudi, Shirin Sadeghi; Montazeri, Naser; Ahmadi, Seyed Javad

    2011-01-01

    A rapid and sensitive method has been developed for the determination of benzaldehyde, a toxic oxidation product of the widely used preservative and co-solvent benzyl alcohol in injectable formulations of non-steroidal anti-inflammatory drugs, diclofenac, vitamin B-complex and Voltaren injection solutions by using dispersive liquid-liquid microextraction followed by gas chromatography. This method involves the use of an appropriate mixture of extraction solvent (43.0 µL 1,2-dichloroethane) and disperser solvent (1.0 mL acetonitrile) for the formation of a cloudy solution in a 5.0-mL aqueous sample containing benzaldehyde. The linear range was 1.0-1000 µg L(-1), and the limit of detection was 0.2 µg L(-1) for benzaldehyde. 2011 © The Japan Society for Analytical Chemistry

  9. First demonstration of rapid shutdown using neon shattered pellet injection for thermal quench mitigation on DIII-D

    NASA Astrophysics Data System (ADS)

    Commaux, N.; Shiraki, D.; Baylor, L. R.; Hollmann, E. M.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Jernigan, T. C.; Meitner, S. J.; Combs, S. K.; Foust, C. R.

    2016-04-01

    Shattered pellet injection (SPI) is one of the prime candidates for the ITER disruption mitigation system because of its deeper penetration and larger particle flux than massive gas injection (MGI) (Taylor et al 1999 Phys. Plasmas 6 1872) using deuterium (Commaux et al 2010 Nucl. Fusion 50 112001, Combs et al 2010 IEEE Trans. Plasma Sci. 38 400, Baylor et al 2009 Nucl. Fusion 49 085013). The ITER disruption mitigation system will likely use mostly high Z species such as neon because of more effective thermal mitigation and pumping constraints on the maximum amount of deuterium or helium that could be injected. An upgrade of the SPI on DIII-D enables ITER relevant injection characteristics in terms of quantities and gas species. This upgraded SPI system was used on DIII-D for the first time in 2014 for a direct comparison with MGI using identical quantities of neon. This comparison enabled the measurements of density perturbations during the thermal quench (TQ) and radiated power and heat loads to the divertor. It showed that SPI using similar quantities of neon provided a faster and stronger density perturbation and neon assimilation, which resulted in a lower conducted energy to the divertor and a faster TQ onset. Radiated power data analysis shows that this was probably due to the much deeper penetration of the neon in the plasma inducing a higher core radiation than in the MGI case. This experiment shows also that the MHD activity during an SPI shutdown (especially during the TQ) is quite different compared to MGI. This favorable TQ energy dissipation was obtained while keeping the current quench (CQ) duration within acceptable limits when scaled to ITER.

  10. First demonstration of rapid shutdown using neon shattered pellet injection for thermal quench mitigation on DIII-D

    DOE PAGES

    Commaux, Nicolas J. C.; Shiraki, Daisuke; Baylor, Larry R.; ...

    2016-03-02

    Shattered pellet injection (SPI) is one of the prime candidates for the ITER disruption mitigation system because of its deeper penetration and larger particle flux than massive gas injection (MGI) (Taylor et al 1999 Phys. Plasmas 6 1872) using deuterium (Commaux et al 2010 Nucl. Fusion 50 112001, Combs et al 2010 IEEE Trans. Plasma Sci. 38 400, Baylor et al 2009 Nucl. Fusion 49 085013). The ITER disruption mitigation system will likely use mostly high Z species such as neon because of more effective thermal mitigation and pumping constraints on the maximum amount of deuterium or helium that couldmore » be injected. An upgrade of the SPI on DIII-D enables ITER relevant injection characteristics in terms of quantities and gas species. This upgraded SPI system was used on DIII-D for the first time in 2014 for a direct comparison with MGI using identical quantities of neon. This comparison enabled the measurements of density perturbations during the thermal quench (TQ) and radiated power and heat loads to the divertor. It showed that SPI using similar quantities of neon provided a faster and stronger density perturbation and neon assimilation, which resulted in a lower conducted energy to the divertor and a faster TQ onset. Radiated power data analysis shows that this was probably due to the much deeper penetration of the neon in the plasma inducing a higher core radiation than in the MGI case. This experiment shows also that the MHD activity during an SPI shutdown (especially during the TQ) is quite different compared to MGI. Furthermore, this favorable TQ energy dissipation was obtained while keeping the current quench (CQ) duration within acceptable limits when scaled to ITER.« less

  11. Sensorimotor impairment and elevated levels of dopamine metabolites in the neostriatum occur rapidly after intranigral injection of 6-hydroxydopamine or gamma-hydroxybutyrate in awake rats.

    PubMed

    Altar, C A; O'Neil, S; Marshall, J F

    1984-03-01

    The unilateral injection of 6-hydroxydopamine (8 micrograms) into the ventral tegmental area of awake rats produced a rapidly developing and irreversible sensory neglect to contralateral tactile stimuli. This neglect developed in a caudal to rostral direction on the affected body surface and coincided with significant elevation in the concentrations of dopamine and two of its metabolites, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the ipsilateral neostriatum. The unilateral injection of procaine or gamma-hydroxybutyric acid (GHB) into the substantia nigra of awake animals also produced a contralateral neglect that developed in a caudal to rostral direction, but the behavioral effect of these drugs diminished within 1 hr. Concentrations of dopamine, dihydroxyphenylacetic acid and homovanillic acid in the neostriatum were markedly elevated during continuous infusions of procaine or gamma-hydroxybutyric acid. The extent of sensory neglect and changes in dopamine metabolism in the neostriatum varied according to the amount of gamma-hydroxybutyric acid injected into the nigra and according to the proximity of injections of gamma-hydroxybutyric acid to the pars compacta. The rapid onset of sensory neglect following microinjections of 6-hydroxydopamine, procaine or gamma-hydroxybutyric acid is consistent with the ability of each of these drugs to block the conduction of impulses in mesostriatal neurons and suggests that concomitant increases in levels of dopamine, dihydroxyphenylacetic acid and homovanillic acid in the neostriatum resulted from decreases in the release of dopamine coupled with increased synthesis of dopamine. These findings also indicate that the catabolism of dopamine to dihydroxyphenylacetic acid or homovanillic acid may originate intraneuronally, without prior release of dopamine and its recapture by mesostriatal terminals, if the flow of impulses in this pathway has been blocked.

  12. Rapid isolation of biomarkers for compound specific radiocarbon dating using high-performance liquid chromatography and flow injection analysis-atmospheric pressure chemical ionisation mass spectrometry.

    PubMed

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Sinninghe Damsté, Jaap S

    2002-11-29

    Repeated semi-preparative normal-phase HPLC was performed to isolate selected biomarkers from sediment extracts for radiocarbon analysis. Flow injection analysis-mass spectrometry was used for rapid analysis of collected fractions to evaluate the separation procedure, taking only 1 min per fraction. In this way 100-1000 microg of glycerol dialkyl glycerol tetraethers, sterol fractions and chlorophyll-derived phytol were isolated from typically 100 g of marine sediment, i.e., in sufficient quantities for radiocarbon analysis, without significant carbon isotopic fractionation or contamination.

  13. INCREASED OIL RECOVERY FROM MATURE OIL FIELDS USING GELLED POLYMER TREATMENTS

    SciTech Connect

    G.P. Willhite; D.W. Green; C.S. McCool

    2003-05-01

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of a three-year research program aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production. The work focused on the gel system composed of polyacrylamide and chromium acetate. The molar mass of the polymer was about six million. Chromium(III) acetate reacted and formed crosslinks between polymer molecules. The crosslinked polymer molecules, or pre-gel aggregates, combine and grow to eventually form a 3-dimensional gel. A fundamental study to characterize the formation and growth of pre-gel aggregates was conducted. Two methods, flow field-flow fractionation (FFFF) and multi-angle laser light scattering (MALLS) were used. Studies using FFFF were inconclusive. Data taken using MALLS showed that at the gel time the average molar mass of gel aggregates increased by a factor of about three while the average size increase was approximately 50%. Increased acetate concentration in the gelant increases the gel time. The in situ performance of an added-acetate system was investigated to determine the applicability for in-depth treatments. Increased acetate concentrations delayed the development of increased flow resistance during gelant injection in short sandpacks. The development of increased flow resistance (in situ gelation) was extended from 2 to 34 days by increasing the acetate-to-chromium ratio from 38 to 153. In situ gelation occurred at a time that was approximately 22% of the bulk gelation time. When carbonate rocks are treated with gel, chromium retention in the rock may limit in

  14. Simultaneously Physically and Chemically Gelling Polymer System utilizing a poly(NIPAAm-co-cysteamine) Based Copolymer

    PubMed Central

    Robb, Stephanie A.; Lee, Bae Hoon; McLemore, Ryan; Vernon, Brent L.

    2010-01-01

    The objective of this work is to create an in situ physically and chemically cross-linking hydrogel for in vivo applications. N-isopropylacrylamide (NIPAAm) was copolymerized with N-acryloxysuccinimide (NASI) via free radical polymerization. Poly(NIPAAm-co-NASI) was further modified to obtain Poly(NIPAAm-co-cysteamine) through a nucleophilic attack on the carbonyl group of the NASI by the amine group of the cysteamine. Modification was verified by nuclear magnetic resonance. In addition to thermo-responsive physical gelling due to the presence of NIPAAm, this system also chemically gels via a Michael-Type addition reaction when mixed with poly(ethylene glycol) diacrylate (PEGDA). The presence of both physical and chemical gelation resulted in material properties that are much improved compared to purely physical gels. The chemical gelation time of the copolymers was not significantly affected by the amount of thiol present due to the increased pKa of the copolymer containing more thiols. In addition, the swelling of the copolymers was highly dependent on temperature and thiol content. Lastly, the rate of nucleophilic attack in the Michael-Type addition reaction was shown to be highly dependent on pH and on the mole ratio of thiol to acrylate. Due to the improved mechanical properties, this material may be better suited for long-term functional replacement applications than other thermo-sensitive physical gels. With further development and biocompatibility testing, this material could potentially be applied as a temperature-responsive injectable biomaterial for functional embolization. PMID:17567067

  15. Rapid functional cardiac imaging after gadolinium injection: Evaluation of a highly accelerated sequence with sparse data sampling and iterative reconstruction

    PubMed Central

    Budjan, Johannes; Haubenreisser, Holger; Henzler, Thomas; Sudarski, Sonja; Schmidt, Michaela; Doesch, Christina; Akin, Ibrahim; Borggrefe, Martin; Meßner, Nadja M.; Schoenberg, Stefan O.; Attenberger, Ulrike I.; Papavassiliu, Theano

    2016-01-01

    To generate a patient-friendly, time-efficient cardiac MRI examination protocol, a highly accelerated real-time CINE MR sequence (SSIR) was acquired in the idle time in between contrast injection and late gadolinium enhancement phase. 20 consecutive patients underwent a cardiac MRI examination including a multi-breath-hold sequence as gold standard (Ref) as well as SSIR sequences with (SSIR-BH) and without breath-hold (SSIR-nonBH). SSIR sequences were acquired 4 minutes after gadolinium injection. Right- (RV) and left-ventricular (LV) volumetric functional parameters were evaluated and compared between Ref and SSIR sequences. Despite reduced contrast between myocardium and intra-ventricular blood, volumetric as well as regional wall movement assessment revealed high agreement between both SSIR sequences and Ref. Excellent correlation and narrow limits of agreements were found for both SSIR-BH and SSIR-nonBH when compared to Ref for both LV (mean LV ejection fraction [EF] Ref: 52.8 ± 12.6%, SSIR-BH 52.3 ± 12.9%, SSIR-nonBH 52.5 ± 12.6%) and RV (mean RV EF Ref: 52.7 ± 9.4%, SSIR-BH 52.0 ± 8.1%, SSIR-nonBH 52.2 ± 9.3%) analyses. Even when acquired in the idle time in between gadolinium injection and LGE acquisition, the highly accelerated SSIR sequence delivers accurate volumetric and regional wall movement information. It thus seems ideal for very time-efficient and robust cardiac MR imaging protocols. PMID:27905543

  16. Effect of various gelling cations on the physical properties of "wet" alginate films.

    PubMed

    Harper, B Allison; Barbut, Shai; Lim, Loong-Tak; Marcone, Massimo F

    2014-04-01

    In this study, the physical properties of "wet" alginate films gelled with various divalent cations (Ba(2+) , Ca(2+) , Mg(2+) , Sr(2+) , and Zn(2+) ) were explored. Additionally, the effect of adding NaCl to the alginate film-forming solution prior to gelling was evaluated. Aside from Mg(2+) , all of the divalent cations were able to produce workable "wet" alginate films. Films gelled with BaCl2 (without added NaCl) had the highest (P < 0.05) tensile strength and Young's modulus while films gelled with CaCl2 (alone) had the highest puncture strength. The Zn-alginate and Sr-alginate films had the highest elongation at break values. Adding NaCl to the alginate film-forming solution increased the viscosity of the solution. Films with added NaCl were less transparent and had lower tensile strength, elongation, and puncture strength than films formed without NaCl in the film-forming solution. ATR-FTIR results showed a slight shift in the asymmetric COO(-) vibrational peak of the alginate when the "wet" alginate films were gelled with Zn(2+) .

  17. Preliminary Assessment of Using Gelled and Hybrid Propellant Propulsion for VTOL/SSTO Launch Systems

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan; OLeary, Robert; Pelaccio, Dennis G.

    1998-01-01

    A novel, reusable, Vertical-Takeoff-and-Vertical-Takeoff-and-Landing, Single-Stage-to-Orbit (VTOL/SSTO) launch system concept, named AUGMENT-SSTO, is presented in this paper to help quantify the advantages of employing gelled and hybrid propellant propulsion system options for such applications. The launch vehicle system concept considered uses a highly coupled, main high performance liquid oxygen/liquid hydrogen (LO2/LH2) propulsion system, that is used only for launch, while a gelled or hybrid propellant propulsion system auxiliary propulsion system is used during final orbit insertion, major orbit maneuvering, and landing propulsive burn phases of flight. Using a gelled or hybrid propellant propulsion system for major orbit maneuver burns and landing has many advantages over conventional VTOL/SSTO concepts that use LO2/LH2 propulsion system(s) burns for all phases of flight. The applicability of three gelled propellant systems, O2/H2/Al, O2/RP-1/Al, and NTO/MMH/Al, and a state-of-the-art (SOA) hybrid propulsion system are examined in this study. Additionally, this paper addresses the applicability of a high performance gelled O2/H2 propulsion system to perform the primary, as well as the auxiliary propulsion system functions of the vehicle.

  18. Rapid determination of piracetam in human plasma and cerebrospinal fluid by micellar electrokinetic chromatography with sample direct injection.

    PubMed

    Yeh, Hsin-Hua; Yang, Yuan-Han; Ko, Ju-Yun; Chen, Su-Hwei

    2006-07-07

    A simple micellar electrokinetic chromatography (MEKC) method with UV detection at 200 nm for analysis of piracetam in plasma and in cerebrospinal fluid (CSF) by direct injection without any sample pretreatment is described. The separation of piracetam from biological matrix was performed at 25 degrees C using a background electrolyte consisting of Tris buffer with sodium dodecyl sulfate (SDS) as the electrolyte solution. Several parameters affecting the separation of the drug from biological matrix were studied, including the pH and concentrations of the Tris buffer and SDS. Under optimal MEKC condition, good separation with high efficiency and short analyses time is achieved. Using imidazole as an internal standard (IS), the linear ranges of the method for the determination of piracetam in plasma and in CSF were all between 5 and 500 microg/mL; the detection limit of the drug in plasma and in CSF (signal-to-noise ratio=3; injection 0.5 psi, 5s) was 1.0 microg/mL. The applicability of the proposed method for determination of piracetam in plasma and CSF collected after intravenous administration of 3g piracetam every 6h and oral administration 1.2g every 6h in encephalopathy patients with aphasia was demonstrated.

  19. Rapid and sensitive solid phase extraction-large volume injection-gas chromatography for the analysis of mineral oil saturated and aromatic hydrocarbons in cardboard and dried foods.

    PubMed

    Moret, Sabrina; Barp, Laura; Purcaro, Giorgia; Conte, Lanfranco S

    2012-06-22

    A rapid off-line solid phase extraction-large volume injection-gas chromatography-flame ionisation detection (SPE-LVI-GC-FID) method, based on the use of silver silica gel and low solvent consumption, was developed for mineral oil saturated hydrocarbon (MOSH) and mineral oil aromatic hydrocarbon (MOAH) determination in cardboard and dried foods packaged in cardboard. The SPE method was validated using LVI with a conventional on-column injector and the retention gap technique (which allowed to inject up to 50 μL of the sample). Detector response was linear over all the concentration range tested (0.5-250 μg/mL), recoveries were practically quantitative, repeatability was good (coefficients of variation lower than 7%) and limit of quantification adequate to quantify the envisioned limit of 0.15 mg/kg proposed in Germany for MOAH analysis in food samples packaged in recycled cardboard. Rapid heating of the GC oven allowed to increase sample throughput (3-4 samples per hour) and to enhance sensitivity. The proposed method was used for MOSH and MOAH determination in selected food samples usually commercialised in cardboard packaging. The most contaminated was a tea sample (102.2 and 7.9 mg/kg of MOSH and MOAH below n-C25, respectively), followed by a rice and a sugar powder sample, all packaged in recycled cardboard. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. A bcl-2 transgene expressed in hepatocytes protects mice from fulminant liver destruction but not from rapid death induced by anti-Fas antibody injection

    PubMed Central

    1996-01-01

    Stimulation of the Fas (APO-1, CD95) receptor, which is present on a variety of cells, usually triggers a process of programmed cell death. Systemic injection of anti-Fas antibody into mice leads to fulminant liver destruction resulting from massive hepatocyte apoptosis, and to rapid death. Hepatocytes bear Fas but do not express Bcl-2, a protein that plays, in a number of conditions, a protective role against apoptosis. We have generated mice whose liver expresses Bcl-2 as the result of bcl-2 transgene placed under the control of the hepatocyte- specific alpha1-anti-trypsin gene promoter, but is otherwise not distinguishable from that of normal mice. These mice display a marked to almost total resistance to liver damage induced by anti-Fas antibody injection. This protective effect of Bcl-2 occurs in the absence of significant variations, in the stimulated livers, in the level of expression of other proteins also involved in resistance or sensitivity to apoptosis, namely Bcl-x, Bax, Bad, Bak, and p53. Mice with protected livers, however, die almost as rapidly as normal mice, which indicates that acute lethality results from stimulation of Fas receptors present on other target organs or cells. PMID:8642244

  1. Predicting blood pressure change caused by rapid injection of propofol during anesthesia induction with a logistic regression model.

    PubMed

    Rau, Ruey-Horng; Li, Yu-Chuan; Cheng, Jen-Kun; Chen, Chien-Chuan; Ko, Yuan-Pi; Huang, Chun-Jen

    2004-06-01

    Propofol is a common intravenous agent for induction and maintenance of anesthesia. The advantage of propofol is rapid recovery of consciousness when the continuous infusion is stopped. Additionally, it has antiemetic effect of reducing postoperative nausea and vomiting. On the other hand, rapid infusion of propofol is painful and may cause hypotension. In this study, we aimed to develop a logistic regression model to accurately predict blood pressure change caused by rapid infusion of propofol. Seventeen variables (including demographic data, past medical history, laboratory data, and blood pressure before induction) were assessed in 200 patients who received propofol for induction of anesthesia for routine surgery. A logistic regression model was derived using these values as independent variables to predict whether a patient would suffer a significant blood pressure change (> 30% decrease from baseline). Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated to evaluate the performance of our prediction model. A cut-off value of 0.17 in the logistic regression model predicted decreased blood pressure with 90.0% sensitivity and, 67.3% specificity. The area under the receiver operating characteristic curve was 0.855. Our prediction model predicts propofol-induced hypotension with acceptable accuracy. Because of the straightforward mathematic formula used, our model can be integrated effortlessly into a hospital information system, providing a reliable and useful decision support for clinical anesthesia staff.

  2. Intramuscular injection of α-synuclein induces CNS α-synuclein pathology and a rapid-onset motor phenotype in transgenic mice

    PubMed Central

    Sacino, Amanda N.; Brooks, Mieu; Thomas, Michael A.; McKinney, Alex B.; Lee, Sooyeon; Regenhardt, Robert W.; McGarvey, Nicholas H.; Ayers, Jacob I.; Notterpek, Lucia; Borchelt, David R.; Golde, Todd E.; Giasson, Benoit I.

    2014-01-01

    It has been hypothesized that α-synuclein (αS) misfolding may begin in peripheral nerves and spread to the central nervous system (CNS), leading to Parkinson disease and related disorders. Although recent data suggest that αS pathology can spread within the mouse brain, there is no direct evidence for spread of disease from a peripheral site. In the present study, we show that hind limb intramuscular (IM) injection of αS can induce pathology in the CNS in the human Ala53Thr (M83) and wild-type (M20) αS transgenic (Tg) mouse models. Within 2–3 mo after IM injection in αS homozygous M83 Tg mice and 3–4 mo for hemizygous M83 Tg mice, these animals developed a rapid, synchronized, and predictable induction of widespread CNS αS inclusion pathology, accompanied by astrogliosis, microgliosis, and debilitating motor impairments. In M20 Tg mice, starting at 4 mo after IM injection, we observed αS inclusion pathology in the spinal cord, but motor function remained intact. Transection of the sciatic nerve in the M83 Tg mice significantly delayed the appearance of CNS pathology and motor symptoms, demonstrating the involvement of retrograde transport in inducing αS CNS inclusion pathology. Outside of scrapie-mediated prion disease, to our knowledge, this findiing is the first evidence that an entire neurodegenerative proteinopathy associated with a robust, lethal motor phenotype can be initiated by peripheral inoculation with a pathogenic protein. Furthermore, this facile, synchronized rapid-onset model of α-synucleinopathy will be highly valuable in testing disease-modifying therapies and dissecting the mechanism(s) that drive αS-induced neurodegeneration. PMID:25002524

  3. Intramuscular injection of α-synuclein induces CNS α-synuclein pathology and a rapid-onset motor phenotype in transgenic mice.

    PubMed

    Sacino, Amanda N; Brooks, Mieu; Thomas, Michael A; McKinney, Alex B; Lee, Sooyeon; Regenhardt, Robert W; McGarvey, Nicholas H; Ayers, Jacob I; Notterpek, Lucia; Borchelt, David R; Golde, Todd E; Giasson, Benoit I

    2014-07-22

    It has been hypothesized that α-synuclein (αS) misfolding may begin in peripheral nerves and spread to the central nervous system (CNS), leading to Parkinson disease and related disorders. Although recent data suggest that αS pathology can spread within the mouse brain, there is no direct evidence for spread of disease from a peripheral site. In the present study, we show that hind limb intramuscular (IM) injection of αS can induce pathology in the CNS in the human Ala53Thr (M83) and wild-type (M20) αS transgenic (Tg) mouse models. Within 2-3 mo after IM injection in αS homozygous M83 Tg mice and 3-4 mo for hemizygous M83 Tg mice, these animals developed a rapid, synchronized, and predictable induction of widespread CNS αS inclusion pathology, accompanied by astrogliosis, microgliosis, and debilitating motor impairments. In M20 Tg mice, starting at 4 mo after IM injection, we observed αS inclusion pathology in the spinal cord, but motor function remained intact. Transection of the sciatic nerve in the M83 Tg mice significantly delayed the appearance of CNS pathology and motor symptoms, demonstrating the involvement of retrograde transport in inducing αS CNS inclusion pathology. Outside of scrapie-mediated prion disease, to our knowledge, this findiing is the first evidence that an entire neurodegenerative proteinopathy associated with a robust, lethal motor phenotype can be initiated by peripheral inoculation with a pathogenic protein. Furthermore, this facile, synchronized rapid-onset model of α-synucleinopathy will be highly valuable in testing disease-modifying therapies and dissecting the mechanism(s) that drive αS-induced neurodegeneration.

  4. Modeling the Rapid Boil-Off of a Cryogenic Liquid When Injected into a Low Pressure Cavity

    NASA Technical Reports Server (NTRS)

    Lira, Eric

    2016-01-01

    Many launch vehicle cryogenic applications require the modeling of injecting a cryogenic liquid into a low pressure cavity. The difficulty of such analyses lies in accurately predicting the heat transfer coefficient between the cold liquid and a warm wall in a low pressure environment. The heat transfer coefficient and the behavior of the liquid is highly dependent on the mass flow rate into the cavity, the cavity wall temperature and the cavity volume. Testing was performed to correlate the modeling performed using Thermal Desktop and Sinda Fluint Thermal and Fluids Analysis Software. This presentation shall describe a methodology to model the cryogenic process using Sinda Fluint, a description of the cryogenic test set up, a description of the test procedure and how the model was correlated to match the test results.

  5. A flow injection analysis system with encapsulated high-density Saccharomyces cerevisiae cells for rapid determination of biochemical oxygen demand.

    PubMed

    Seo, Kyo Seong; Choo, Kwang Ho; Chang, Ho Nam; Park, Joong Kon

    2009-05-01

    The biochemical oxygen demand (BOD) determination was studied using a novel flow injection analysis (FIA) system with encapsulated Saccharomyces cerevisiae cells and an oxygen electrode and was compared with conventional 5-day BOD tests. S. cerevisiae cells were packed in a calcium alginate capsule at a dry cell weight of 250 g/l of capsule core. The level of dissolved oxygen (DO) was reduced due to the enhanced respiratory activity of the microbial cells when the injected nutrient passed through the bioreactor. The decrease in DO (DeltaDO) was intensified with the amount of microbial cells packed in the bioreactor. However, the specific DeltaDO decreased as the amount of cells loaded in the bioreactor increased. The DeltaDO value was dependent on the pH and temperature of the mobile phase and reached its maximum value at 35 degrees C and pH 7-8. Also, DeltaDO became larger at longer response times as the flow rate of the mobile phase decreased. The measurement of DeltaDO was repeated more than six times consecutively using a 20-ppm standard glucose and glutamic acid solution, which confirmed the reproducibility with a standard deviation of 0.95%. A strong linear correlation between DeltaDO and BOD was also observed. The 5-day BOD values of actual water and wastewater samples were in accordance with the BOD values obtained by this FIA method using encapsulated S. cerevisiae cells. Unlike the cell-immobilized bead system, there was no contamination of the bioreactor resulting from any leak of yeast cells from the sensor capsules during BOD measurements.

  6. Rapid Decline in HIV Incidence Among Persons Who Inject Drugs During a Fast-Track Combination Prevention Program After an HIV Outbreak in Athens.

    PubMed

    Sypsa, Vana; Psichogiou, Mina; Paraskevis, Dimitrios; Nikolopoulos, Georgios; Tsiara, Chrissa; Paraskeva, Dimitra; Micha, Katerina; Malliori, Meni; Pharris, Anastasia; Wiessing, Lucas; Donoghoe, Martin; Friedman, Samuel; Jarlais, Don Des; Daikos, Georgios; Hatzakis, Angelos

    2017-05-15

    A "seek-test-treat" intervention (ARISTOTLE) was implemented in response to an outbreak of human immunodeficiency virus (HIV) infection among persons who inject drugs (PWID) in Athens. We assess trends in HIV incidence, prevalence, risk behaviors and access to prevention/treatment. Methods included behavioral data collection, provision of injection equipment, HIV testing, linkage to opioid substitution treatment (OST) programs and HIV care during 5 rounds of respondent-driven sampling (2012-2013). HIV incidence was estimated from observed seroconversions. Estimated coverage of the target population was 88% (71%-100%; 7113 questionnaires/blood samples from 3320 PWID). The prevalence of HIV infection was 16.5%. The incidence per 100 person-years decreased from 7.8 (95% confidence interval, 4.6-13.1) (2012) to 1.7 (0.55-5.31) (2013; P for trend = .001). Risk factors for seroconversion were frequency of injection, homelessness, and history of imprisonment. Injection at least once daily declined from 45.2% to 18.8% (P < .001) and from 36.8% to 26.0% (P = .007) for sharing syringes, and the proportion of undiagnosed HIV infection declined from 84.3% to 15.0% (P < .001). Current OST increased from 12.2% to 27.7% (P < .001), and 48.4% of unlinked seropositive participants were linked to HIV care through 2013. Repeat participants reported higher rates of adequate syringe coverage, linkage to HIV care and OST. Multiple evidence-based interventions delivered through rapid recruitment in a large proportion of the population of PWID are likely to have helped mitigate this HIV outbreak.

  7. On-line simultaneous and rapid separation of anions and cations from a single sample using dual-capillary sequential injection-capillary electrophoresis.

    PubMed

    Gaudry, Adam J; Guijt, Rosanne M; Macka, Mirek; Hutchinson, Joseph P; Johns, Cameron; Hilder, Emily F; Dicinoski, Greg W; Nesterenko, Pavel N; Haddad, Paul R; Breadmore, Michael C

    2013-06-05

    A novel capillary electrophoresis (CE) approach has been developed for the simultaneous rapid separation and identification of common environmental inorganic anions and cations from a single sample injection. The method utilised a sequential injection-capillary electrophoresis instrument (SI-CE) with capacitively-coupled contactless conductivity detection (C(4)D) constructed in-house from commercial-off-the-shelf components. Oppositely charged analytes from a single sample plug were simultaneously injected electrokinetically onto two separate capillaries for independent separation and detection. Injection was automated and may occur from a syringe or be directly coupled to an external source in a continuous manner. Software control enabled high sample throughput (17 runs per hour for the target analyte set) and the inclusion of an isolation valve allowed the separation capillaries to be flushed, increasing throughput by removing slow migrating species as well as improving repeatability. Various environmental and industrial samples (subjected only to filtering) were analysed in the laboratory with a 3 min analysis time which allowed the separation of 23 inorganic and small organic anions and cations. Finally, the system was applied to an extended automated analysis of Hobart Southern Water tap water for a period of 48 h. The overall repeatability of the migration times of a 14 analyte standard sample was less than 0.74% under laboratory conditions. LODs ranged from 5 to 61 μg L(-1). The combination of automation, high confidence of peak identification, and low limits of detection make this a useful system for the simultaneous identification of a range of common inorganic anions and cations for discrete or continuous monitoring applications.

  8. κ-Carrageenan/locust bean gum as hard capsule gelling agents.

    PubMed

    He, Huanghuang; Ye, Jing; Zhang, Xueqin; Huang, Yayan; Li, Xiaohui; Xiao, Meitian

    2017-11-01

    A novel gelling agent, comprising blended κ-carrageenan (κ-C), a seaweed polysaccharide and locust bean gum (LBG), was used to prepare hard capsules. The distinct synergism between κ-C and LBG were verified by the textural profile analysis (TPA), FTIR and rheological measurement. Afterwards, films and hard capsules were prepared with the optimized LBG/κ-C blend gel. And the mechanical properties and morphology of films and hard capsules were analyzed by tensile testing and SEM, respectively. The results showed that the LBG/κ-C at 1:3 ratio could serve as an excellent gelling agent, which endowed hard capsule with the promoted mechanical properties, homogenous and smooth surface morphology. This work suggests that a novel blended LBG/κ-C gelling agent successfully prepared for hard capsules with improving physicochemical properties. Copyright © 2017. Published by Elsevier Ltd.

  9. Investigation of the application of gelled polymer systems for permeability modification in pertroleum reservoirs: Second annual report, October 1986--September 1987

    SciTech Connect

    Willhite, G.P.; Green, D.W.; Thiele, J.L.; Young, Teng-Shau; Mertes, K.B.

    1988-11-01

    Research is reported for the second year of an integrated research program to improve the performance and predictability of in situ gelation processes designed to alter the permeability of porous rocks. The research is focused on physical and chemical description of gelling systems, experimental studies of in situ gelation, and development of correlations and/or mathematical models for the design of in situ gelling processes. Physical characterization studies resulted in determination of long-term swelling and syneresis properties of Cr(III)/xanthan gum and Cr(III)-PAAM (polyacrylamide) gels and measurement of molecular weight distributions of PAAM and hydrolyzed PAAM in Berea core effluents. The gelation behavior of emulsion polyacrylamides was examined. An empirical rate expression for the kinetics of the reaction between Cr(III) and an unhydrolyzed polyacrylamide was developed. Characteristics of several chrome/polymer gelling systems were studied under oscillatory shear and superposition of steady and oscillatory shear. In our studies of in situ gelation, an experimental program to determine the flow characteristics of biopolymer in unconsolidated sandpacks was completed. Empirical correlations were developed between polymer concentration and the power law parameters required to estimate polymer flow characteristics. Research was completed on the in situ gelation of a thiourea/Cr(VI)/cationic polyacrylamide system in unconsolidated sandpacks. Preliminary results were obtained on the long-term stability of Cr(III)/xanthan gels under continued water injection. Research on the aluminum citrate process of permeability modification was focused on adsorption and desorption studies of aluminum on silica sand and crushed Berea sandstone core material.

  10. Evaluation of guar gum derivatives as gelling agents for microbial culture media.

    PubMed

    Gangotri, Waikhom; Jain-Raina, Ruchi; Babbar, Shashi B

    2012-05-01

    Guar gum, a galactomannan, has been reported to be an inexpensive substitute of agar for microbial culture media. However, its use is restricted probably because of (1) its highly viscous nature even at high temperatures, making dispensing of the media to Petri plates difficult and (2) lesser clarity of the guar gum gelled media than agar media due to impurities present in guar gum. To overcome these problems, three guar gum derivatives, carboxymethyl guar, carboxymethyl hydroxypropyl guar and hydroxypropyl guar, were tested as gelling agents for microbial growth and differentiation. These were also evaluated for their suitability for other routine microbiological methods, such as, enumeration, use of selective and differential media, and antibiotic sensitivity test. For evaluation purpose, growth and differentiation of eight fungi and eight bacteria grown on the media gelled with agar (1.5%), guar gum (4%) or one of the guar gum derivatives (4%), were compared. All fungi and bacteria exhibited normal growth and differentiation on all these media. Generally, growth of most of the fungi was better on guar gum derivatives gelled medium than on agar medium. The enumeration carried out for Serratia sp. and Pseudomonas aeruginosa by serial dilution and pour plate method yielded similar counts in all the treatments. Likewise, the selective succinate medium, specific for P. aeruginosa, did not allow growth of co-inoculated Bacillus sp. even if gelled with guar gum derivatives. The differential medium, Congo red mannitol agar could not differentiate between Agrobacterium tumefaciens and Rhizobium meliloti on color basis, if gelled with guar gum or any of its derivatives However, for antibiotic sensitivity tests for both Gram-positive and -negative bacteria, guar gum and its derivatives were as effective as agar.

  11. High Energy, Low Temperature Gelled Bi-propellant Formulation Preparation Method

    NASA Technical Reports Server (NTRS)

    DiSalvo, Roberto (Inventor)

    2013-01-01

    A method for preparing a gelled liquid propane (GLP) composition comprises the introduction of liquid propane into an evacuated mixing vessel containing a gellant and mixing the liquid propane with the gellant. A bi-propellant system comprising GLP is particularly well-suited for outer planet missions greater than 3 AU from the sun and also functions in earth and near earth environments. Additives such as powders of boron, carbon, lithium, and/or aluminum can be added improve performance or enhance hypergolicity. The gelling agent can be silicon dioxide, clay, carbon, or organic or inorganic polymers. The bi-propellant system may be, but need not be, hypergolic.

  12. Development and Validation of a Rapid Turbidimetric Assay to Determine the Potency of Cefuroxime Sodium in Powder for Injection

    PubMed Central

    Vieira, Daniela C. M.; Fiuza, Thalita F. M.; Salgado, Hérida R.N.

    2014-01-01

    The cefuroxime sodium is a second generation cephalosporin indicated for infections caused by Gram-positive and Gram-negative microorganisms. Although this drug is highly studied and researched regarding the antimicrobial activity, pharmacokinetics and pharmacodynamics, there are few studies regarding the development of analytical methodology for this cephalosporin. Thus, research involving analytical methods is essential and highly relevant to optimize its analysis in the pharmaceutical industry and guarantee the quality of the product already sold. This study describes the development and validation of a microbiological assay applying the turbidimetric method for the determination of cefuroxime, using Micrococcus luteus ATCC 9341 as micro-organism test and 3x3 parallel line assay design, with nine tubes for each assay, as recommended by the Brazilian Pharmacopoeia. The developed and validated method showed excellent results of linearity, seletivity, precision and robustness, in the concentration range from 30.0 to 120.0 mg/mL, with 100.21% accuracy and content 99.97% to cefuroxime sodium in injectable pharmaceutical form. PMID:25438016

  13. Sequential injection method for rapid and simultaneous determination of 236U, 237Np, and Pu isotopes in seawater.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter; Golser, Robin

    2013-11-19

    An automated analytical method implemented in a novel dual-column tandem sequential injection (SI) system was developed for simultaneous determination of (236)U, (237)Np, (239)Pu, and (240)Pu in seawater samples. A combination of TEVA and UTEVA extraction chromatography was exploited to separate and purify target analytes, whereupon plutonium and neptunium were simultaneously isolated and purified on TEVA, while uranium was collected on UTEVA. The separation behavior of U, Np, and Pu on TEVA-UTEVA columns was investigated in detail in order to achieve high chemical yields and complete purification for the radionuclides of interest. (242)Pu was used as a chemical yield tracer for both plutonium and neptunium. (238)U was quantified in the sample before the separation for deducing the (236)U concentration from the measured (236)U/(238)U atomic ratio in the separated uranium target using accelerator mass spectrometry. Plutonium isotopes and (237)Np were measured using inductively coupled plasma mass spectrometry after separation. The analytical results indicate that the developed method is robust and efficient, providing satisfactory chemical yields (70-100%) of target analytes and relatively short analytical time (8 h/sample).

  14. Rapid determination of chromium(VI) in electroplating waste water by use of a spectrophotometric flow injection system.

    PubMed

    Yuan, Dong; Fu, Dayou; Wang, Rong; Yuan, Jigang

    2008-11-01

    A new rapid and sensitive FI method is reported for spectrophotometric determination of trace chromium(VI) in electroplating waste water. The method is based on the reaction of Cr(VI) with sodium diphenylamine sulfonate (DPH) in acidic medium to form a purple complex (lambda(max) = 550 nm). Under the optimized conditions, the calibration curve is linear in the range 0.04-3.8 microg ml(-1) at a sampling rate of 30 h(-1). The detection limit of the method is 0.0217 microg ml(-1), and the relative standard deviation is 1.1% for eight determinations of 2 microg ml(-1) Cr(VI). The proposed method was applied to the determination of chromium in electroplating waste water with satisfactory results.

  15. Rapid evaluation of doping-spike carrier concentration levels in millimetre-wave GaAs Gunn diodes with hot-electron injection

    NASA Astrophysics Data System (ADS)

    Farrington, N. E. S.; Carr, M. W.; Missous, M.

    2010-12-01

    This paper describes a novel method for fast, accurate evaluation of doping-spike carrier concentrations in hot-electron injected GaAs Gunn diodes. The technique relies on current asymmetry measurements obtained using pulsed-dc testing of on-wafer quasi-planar Gunn diode test structures, which removes the need for full device fabrication. Small changes in carrier concentration can easily be detected (at a nominal value of 1 × 1018 cm-3) and a greater sensitivity than conventional techniques is demonstrated at the doping levels used. In addition, test structure fabrication can be integrated into the initial Gunn diode front side production process allowing a rapid in-process test to be carried out thus leading to a significant reduction in material characterization cycle time.

  16. Rapid determination of isoamyl nitrite in pharmaceutical preparations by flow injection analysis with on-line UV irradiation and luminol chemiluminescence detection.

    PubMed

    Kishikawa, Naoya; Kondo, Naoko; Amponsaa-Karikari, Abena; Kodamatani, Hitoshi; Ohyama, Kaname; Nakashima, Kenichiro; Yamazaki, Shigeo; Kuroda, Naotaka

    2014-02-01

    Isoamyl nitrite is used as a therapeutic reagent for cardiac angina and as an antidote for cyanide poisoning, but it is abused because of its euphoric properties. Therefore, a method to determine isoamyl nitrite is required in many fields, including pharmaceutical and forensic studies. In this study, a simple, rapid and sensitive method for the determination of isoamyl nitrite was developed using a flow injection analysis system equipped with a chemiluminescence detector and on-line photoreactor. This method is based on on-line ultraviolet irradiation of isoamyl nitrite and subsequent luminol chemiluminescence detection without the addition of an oxidant. A linear standard curve was obtained up to 1.0 μM of isoamyl nitrite with a detection limit (blank + 3SD) of 0.03 μM. The method was successfully applied to determine isoamyl nitrite content in pharmaceutical preparations.

  17. Incorporation of flow injection analysis with dual-wavelength overlapping resonance Rayleigh scattering for rapid determination of malachite green and its metabolite in fish.

    PubMed

    Zhu, Jinghui; Qin, Mingyou; Liu, Shaopu; Liu, Zhongfang; Yang, Jidong; Hu, Xiaoli

    2014-09-15

    A flow injection analysis (FIA) system combined with dual-wavelength overlapping resonance Rayleigh scattering (DWO-RRS) has been established and validated for rapid determination of malachite green (MG) and its metabolite in fish samples. Under experimental condition, MG would react with Erythrosin (Ery) to form ion-association complexes, resulting in the occurrence of two RRS peaks and a dramatic enhancement of RRS intensity. The maximum RRS peaks were located at 286 nm and 337 nm. It is noted that the increments of both of these two peaks were proportional to the concentration of MG. The detection limit of DWO-RRS was 1.5 ng/mL, which was comparable to several reported methods. Moreover, the results of real sample analysis exhibited an acceptable recovery between 97.5% and 103.6%, indicating that the method had good reproducibility.

  18. Incorporation of flow injection analysis with dual-wavelength overlapping resonance Rayleigh scattering for rapid determination of malachite green and its metabolite in fish

    NASA Astrophysics Data System (ADS)

    Zhu, Jinghui; Qin, Mingyou; Liu, Shaopu; Liu, Zhongfang; Yang, Jidong; Hu, Xiaoli

    2014-09-01

    A flow injection analysis (FIA) system combined with dual-wavelength overlapping resonance Rayleigh scattering (DWO-RRS) has been established and validated for rapid determination of malachite green (MG) and its metabolite in fish samples. Under experimental condition, MG would react with Erythrosin (Ery) to form ion-association complexes, resulting in the occurrence of two RRS peaks and a dramatic enhancement of RRS intensity. The maximum RRS peaks were located at 286 nm and 337 nm. It is noted that the increments of both of these two peaks were proportional to the concentration of MG. The detection limit of DWO-RRS was 1.5 ng/mL, which was comparable to several reported methods. Moreover, the results of real sample analysis exhibited an acceptable recovery between 97.5% and 103.6%, indicating that the method had good reproducibility.

  19. Ultra trace determination of 31 pesticides in water samples by direct injection-rapid resolution liquid chromatography-electrospray tandem mass spectrometry.

    PubMed

    Díaz, Laura; Llorca-Pórcel, Julio; Valor, Ignacio

    2008-08-22

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for the detection of pesticides in tap and treated wastewater was developed and validated according to the ISO/IEC 17025:1999. Key features of this method include direct injection of 100 microL of sample, an 11 min separation by means of a rapid resolution liquid chromatography system with a 4.6 mm x 50 mm, 1.8 microm particle size reverse phase column and detection by electrospray ionization (ESI) MS-MS. The limits of detection were below 15 ng L(-1) and correlation coefficients for the calibration curves in the range of 30-2000 ng L(-1) were higher than 0.99. Precision was always below 20% and accuracy was confirmed by external evaluation. The main advantages of this method are direct injection of sample without preparative procedures and low limits of detection that fulfill the requirements established by the current European regulations governing pesticide detection.

  20. Rapid determination of zinc and iron in foods by flow-injection analysis with flame atomic-absorption spectrophotometry and slurry nebulization.

    PubMed

    de Andrade, J C; Strong, F C; Martin, N J

    1990-07-01

    A rapid method of determining zinc and iron in food by flame atomic-absorption spectrophotometry with slurry nebulization into an air-acetylene flame has been developed. A V-groove, clog-free Babington-type nebulizer, coupled to a single-line flow-injection analysis (FIA) system, was employed to introduce the slurry into the spray chamber. Under the FIA conditions described, an injection frequency of 120/hr is possible, with negligible carry-over and memory effects. The calibration graphs were obtained by using various concentrations (up to 0.1 g/ml) of white bean homogenate as standards, rather than solutions. The method has been applied to various kinds of foods, including grains, vegetables, fruits and sausage. Homogenization of semi-prepared samples to form slurries took only 4 min. Relative deviations between results by the slurry and solution methods for both elements averaged 2-3%. Detection limits by the slurry method were 0.3 mug/ml Zn and 0.6 mug/ml Fe.

  1. Rapid screening of haloacetamides in water using salt-assisted liquid-liquid extraction coupled injection-port silylation gas chromatography-mass spectrometry.

    PubMed

    Chen, Tzu-Ling; Tzing, Shin-Hwa; Ding, Wang-Hsien

    2015-11-27

    The rapid screening of trace amounts of the nitrogenous disinfection by-products, haloacetamides (HAcAms), in drinking and swimming pool water was performed by a simple and reliable procedure based on salt-assisted liquid-liquid extraction (SALLE) combined with injection-port silylation gas chromatography-mass spectrometry (IPS-GC-MS) method. The optimal SALLE conditions involved the injection of 4-mL of ethyl acetate into a 10-mL water sample (pH 7) containing 3-g of sodium sulfate. After vortex extraction for 1min and centrifugation, 10μL of the extract (mixed with 1μL of MTBSTFA) was directly determined by IPS-GC-MS. The limits of quantitation (LOQs) were determined to be 0.03-0.3μg/L. Precision, as indicated by relative standard deviations (RSDs), was less than 10% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 76% and 94%. The SALLE plus IPS-GC-MS was successfully applied to quantitatively determine HAcAms from drinking and swimming pool water samples, and the total concentrations of the compounds ranged from 0.43 to 4.03μg/L. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. A simple and rapid flow-injection chemiluminescence method for the determination of noscapine with Ru(phen)3(2+)-Ce(IV) system.

    PubMed

    Rezaei, Behzad; Mokhtari, Ali; Khayamian, Taghi

    2007-08-01

    A new flow injection chemiluminescence (CL) system was used for the determination of noscapine. This technique is based on the reduction effect of noscapine on the Ru(phen)3(3+), which is produced by reaction between Ru(phen)3(2+) and acidic Ce(IV) solutions, and this rapid reduction produces strong CL. Calibration plots were linear over the range of 3.0 x 10(-7) - 2.0 x 10(-6) mol L(-1) and 2.0 x 10(-6) - 2.0 x 10(-4) mol L(-1). The CL intensity was so high, that it is able to produce a detection limit of 6.6 x 10(-8) M noscapine (3sigma). The relative standard deviation of 2.0 x 10(-6) M noscapine was 1.0% (n=10). The proposed method was successfully applied for the flow injection determination of noscapine in cough and Tonin syrup samples. The results of real sample analyses show good recovery percentages (97.3-102.4%). The minimum sampling rate was 100 samples per hour.

  3. Synthesis, characterization and properties of a physically and chemically gelling polymer system using poly(NIPAAm-co-HEMA-acrylate) and poly(NIPAAm-co-cysteamine).

    PubMed

    Bearat, Hanin H; Lee, Bae Hoon; Valdez, Jorge; Vernon, Brent L

    2011-01-01

    The aim of this work was to develop a simultaneous physically and chemically gelling system using NIPAAm co-polymers. The in situ polymer gel was obtained by synthesizing poly(NIPAAm-co-HEMAacrylate) and poly(NIPAAm-co-cysteamine) through free radical polymerization and further nucleophilic substitution. The purpose of the dual gelation is that physical gelation would take place at higher temperatures as the NIPAAm chains associate, while chemical gelation would occur through a Michael-type addition reaction, resulting in a cross-link forming through a nucleophilic attack of the thiolate on the acrylate. The structure of each co-polymer was then verified using (1)H-NMR and FT-IR spectroscopy. The corresponding lower critical solution temperature and phase transition behavior of each co-polymer was analyzed through cloud point and DSC, while mechanical properties were investigated through rheology. Swelling behavior was also monitored at different temperatures. The resulting polymer system demonstrated properties compatible with physiological conditions, forming a gel at pH 7.4 and at temperatures near body temperature. The hydrogel also showed reduced viscoelastic flow at low frequency stress, and increased strength than purely physical or chemical gels. Swelling behavior was determined to be temperature-dependent; however, no difference was observed in swelling percent beyond 48 h. Having the ability to alter these co-polymers through various synthesis parameters and techniques, this hydrogel can potentially be used as an injectable, waterborne gelling material for biomedical applications such as endovascular embolization.

  4. Gelling ability and crystal morphology of sunflower wax in soybean oil

    USDA-ARS?s Scientific Manuscript database

    Plant waxes can effectively form organogels with vegetable oils and these organogels have drawn considerable interests as alternatives to solid fats containing trans fats and saturated fats in margarines and spreads. Among them sunflower wax showed the most pronounced gelling ability. In an attempt ...

  5. Effect of molecular characteristics of Konjac glucomannan on gelling and rheological properties of Tilapia myofibrillar protein.

    PubMed

    Jian, Wenjie; Wu, Huayi; Wu, Lanlan; Wu, Yunhui; Jia, Lina; Pang, Jie; Sun, Yuan-Ming

    2016-10-05

    Konjac glucomannan (KGM) is an important gelling agent in composite gels. This study aimed to investigate the effects of KGM molecular characteristics (molecular weight, size and conformation) on gelling properties of Tilapia myofibrillar protein (TMP). In this work, TMP composite gels were prepared under neutral pH with varying KGM (native KGM, 10kGy-KGM, 20kGy-KGM, and 100kGy-KGM) of different molecular characteristics. Native KGM, 10kGy-KGM, and 20kGy-KGM exerted negative effect on gel strength or whiteness of TMP gels. Interestingly 100kGy-KGM improved gelling properties and whiteness of TMP gels. Such effects presented by varying KGM were attributed the physical filling behaviors and the interaction between KGM and TMP. These behaviors or interactions are resulted from different molecular size and conformation. Smaller molecular size (root-mean square radius, Rz 20.2nm) and approximated spherical conformation in 100kGy-KGM enhanced its interaction with TMP and maintained its compact and smooth structure, but the larger molecular size (Rz≥40.2nm) and random coil conformation in other KGMs inhibited part of actins from gelling and deteriorated the network structure. Our study provided principle knowledge to understand the structure-functions relationships of KGM-TMP composite gels. These results can be used to provide theoretical guidance for surimi gel processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. [Evaluation on gelling properties of shuanghuanglian in situ gel by dynamic rheology].

    PubMed

    Chen, Liang-mian; Wang, Jin-yu; Tong, Yan; Zheng, Bing-lin

    2012-10-01

    To determine the rheological properties of shuanghuanglian in situ gel (SHL-gel) by using dynamic rheological experiments, in order to evaluate its gelling properties shuanghuanglian in situ gel and predict its gelling behavior in vivo. Rheological parameters were determined by scanning of shear rate and frequency at different temperatures. The phase transition process from liquid to semisolid was described by testing of process heating/cooling and acute heating/cooling. SHL-gel was Newtonian fluid under the conditions of a phase angle approaching 90 degrees at low temperature or room temperature, with its viscous characteristics dominated. It was shear-thinning pseudoplastic fluid under the conditions of a low phase angle at body temperature, with its elastic characteristics dominated. During the phase transition process, the phase angle delta was getting sharp, with exponential increase of the modulus. The gelling temperature (Tg) was at (35.38 +/- 0.05) degrees C, the phase transition temperature ranged from 33.71 to 37.01%, and phase transition time was 140 s. The dynamic rheological experiment characterizes the gelling properties of Shuanghuanglian in situ gel so precisely that it can be used as the basis of for in vitro evaluation and quality control of products.

  7. Metallized Gelled Propellants: Oxygen/RP-1/Aluminum Rocket Heat Transfer and Combustion Measurements

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan; Zakany, James S.

    1996-01-01

    A series of rocket engine heat transfer experiments using metallized gelled liquid propellants was conducted. These experiments used a small 20- to 40-lb/f thrust engine composed of a modular injector, igniter, chamber and nozzle. The fuels used were traditional liquid RP-1 and gelled RP-1 with 0-, 5-, and 55-percentage by weight loadings of aluminum particles. Gaseous oxygen was used as the oxidizer. Three different injectors were used during the testing: one for the baseline O(2)/RP-1 tests and two for the gelled and metallized gelled fuel firings. Heat transfer measurements were made with a rocket engine calorimeter chamber and nozzle with a total of 31 cooling channels. Each chamber used a water flow to carry heat away from the chamber and the attached thermocouples and flow meters allowed heat flux estimates at each of the 31 stations. The rocket engine Cstar efficiency for the RP-1 fuel was in the 65-69 percent range, while the gelled 0 percent by weight RP-1 and the 5-percent by weight RP-1 exhibited a Cstar efficiency range of 60 to 62% and 65 to 67%, respectively. The 55-percent by weight RP-1 fuel delivered a 42-47% Cstar efficiency. Comparisons of the heat flux and temperature profiles of the RP-1 and the metallized gelled RP-1/A1 fuels show that the peak nozzle heat fluxes with the metallized gelled O2/RP-1/A1 propellants are substantially higher than the baseline O2/RP-1: up to double the flux for the 55 percent by weight RP-1/A1 over the RP-1 fuel. Analyses showed that the heat transfer to the wall was significantly different for the RP-1/A1 at 55-percent by weight versus the RP-1 fuel. Also, a gellant and an aluminum combustion delay was inferred in the 0 percent and 5-percent by weight RP-1/A1 cases from the decrease in heat flux in the first part of the chamber. A large decrease in heat flux in the last half of the chamber was caused by fuel deposition in the chamber and nozzle. The engine combustion occurred well downstream of the injector face

  8. Design and baseline findings of a large-scale rapid response to an HIV outbreak in people who inject drugs in Athens, Greece: the ARISTOTLE programme.

    PubMed

    Hatzakis, Angelos; Sypsa, Vana; Paraskevis, Dimitrios; Nikolopoulos, Georgios; Tsiara, Chrissa; Micha, Katerina; Panopoulos, Anastasios; Malliori, Meni; Psichogiou, Mina; Pharris, Anastasia; Wiessing, Lucas; van de Laar, Marita; Donoghoe, Martin; Heckathorn, Douglas D; Friedman, Samuel R; Des Jarlais, Don C

    2015-09-01

    To (i) describe an intervention implemented in response to the HIV-1 outbreak among people who inject drugs (PWIDs) in Greece (ARISTOTLE programme), (ii) assess its success in identifying and testing this population and (iii) describe socio-demographic characteristics, risk behaviours and access to treatment/prevention, estimate HIV prevalence and identify risk factors, as assessed at the first participation of PWIDs. A 'seek, test, treat, retain' intervention employing five rounds of respondent-driven sampling. Athens, Greece (2012-13). A total of 3320 individuals who had injected drugs in the past 12 months. ARISTOTLE is an intervention that involves reaching out to high-risk, hard-to-reach PWIDs ('seek'), engaging them in HIV testing and providing information and materials to prevent HIV ('test') and initiating and maintaining anti-retroviral and opioid substitution treatment for those testing positive ('treat' and 'retain'). Blood samples were collected for HIV testing and personal interviews were conducted. ARISTOTLE recruited 3320 PWIDs during the course of 13.5 months. More than half (54%) participated in multiple rounds, resulting in 7113 visits. HIV prevalence was 15.1%. At their first contact with the programme, 12.5% were on opioid substitution treatment programmes and the median number of free syringes they had received in the preceding month was 0. In the multivariable analysis, apart from injection-related variables, homelessness was a risk factor for HIV infection in male PWIDs [odds ratio (OR) yes versus no = 1.89, 95% confidence interval (CI) = 1.41, 2.52] while, in female PWIDS, the number of sexual partners (OR for > 5 versus one partner in the past year = 4.12, 95% CI = 1.93, 8.77) and history of imprisonment (OR yes versus no = 2.76, 95% CI = 1.43, 5.31) were associated with HIV. In Athens, Greece, the ARISTOTLE intervention for identifying HIV-positive people among people who inject drugs (PWID) facilitated rapid

  9. Design and baseline findings of a large-scale rapid response to an HIV outbreak in people who inject drugs in Athens, Greece: the ARISTOTLE programme

    PubMed Central

    Hatzakis, Angelos; Sypsa, Vana; Paraskevis, Dimitrios; Nikolopoulos, Georgios; Tsiara, Chrissa; Micha, Katerina; Panopoulos, Anastasios; Malliori, Meni; Psichogiou, Mina; Pharris, Anastasia; Wiessing, Lucas; van de Laar, Marita; Donoghoe, Martin; Heckathorn, Douglas D.; Friedman, Samuel R.; Des Jarlais, Don C.

    2016-01-01

    -positive people among people who inject drugs (PWID) facilitated rapid identification of a hidden population experiencing an outbreak and provided HIV testing, counselling and linkage to care. According to ARISTOTLE data, the 2011 HIV outbreak in Athens resulted in 15% HIV infection among PWID. Risk factors for HIV among PWID included homelessness in men and history of imprisonment and number of sexual partners in women. PMID:26032121

  10. Rapid automated assay of anti-oxidation/radical-scavenging activity of natural substances by sequential injection technique (SIA) using spectrophotometric detection.

    PubMed

    Polásek, Miroslav; Skála, Petr; Opletal, Lubomír; Jahodár, Ludek

    2004-07-01

    A PC-controlled sequential injection analysis (SIA) system equipped with a spectrophotometric diode-array detector is used for rapid monitoring and evaluation of antioxidation/radical scavenging activity of biological samples. The automated method is based on the known reaction of stable 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH) with antioxidants in organic or aqueous-organic media resulting in bleaching of DPPH due to its "quenching" by the interaction with the analytes. The decrease of the absorbance of DPPH (compared to blank experiment carried out with water-ethanol 1:1 instead of the test solution) measured at 525 nm is related to concentration of an antioxidant in the test solution. With the optimised SIA procedure it is possible to detect down to micromolar concentrations of model antioxidants such as ascorbic acid, caffeic acid, (+)-catechin, (-)-epicatechin and rutin and to evaluate the concentration of these antioxidants in the micromolar to millimolar range. The sample throughput is 45 h(-1). Thanks to its rapidity and sensitivity, the proposed SIA method is suitable for performing routine screening tests for the presence of various antioxidants in large series of lyophilised herbal or mushroom extracts (the amount of sample needed for the analysis is several milligrams).

  11. Formulation and evaluation of floating oral in situ gelling system of amoxicillin.

    PubMed

    Patel, Dasharath M; Patel, Divyesh K; Patel, Chhagan N

    2011-01-01

    Purpose. Effective Helicobacter pylori eradication requires delivery of the antibiotic locally in the stomach. High dose of amoxicillin (750 to 1000 mg) is difficult to incorporate in floating tablets but can easily be given in liquid dosage form. Keeping the above facts in mind, we made an attempt to develop a new floating in situ gelling system of amoxicillin with increased residence time using sodium alginate as gelling polymer to eradicate H. pylori. Methods. Floating in situ gelling formulations were prepared using sodium alginate, calcium chloride, sodium citrate, hydroxypropyl methyl cellulose K100, and sodium bicarbonate. The prepared formulations were evaluated for solution viscosity, floating lag time, total floating time, and in vitro drug release. The formulation was optimized using a 3(2) full factorial design. Dissolution data were fitted to various models to ascertain kinetic of drug release. Regression analysis and analysis of variance were performed for dependent variables. Results. All formulations (F(1)-F(9)) showed floating within 30 s and had total floating time of more than 24 h. All the formulations showed good pourability. It was observed that concentration of sodium alginate and HPMC K100 had significant influence on floating lag time, cumulative percentage drug release in 6 h and 10 h. The batch F(8) was considered optimum since it showed more similarity in drug release (f(2) = 74.38) to the theoretical release profile. Conclusion. Floating in situ gelling system of amoxicillin can be formulated using sodium alginate as a gelling polymer to sustain the drug release for 10 to 12 h with zero-order release kinetics.

  12. Metallized Gelled Propellants: Oxygen/RP-1/Aluminum Rocket Engine Calorimeter Heat Transfer Measurements and Analysis

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan

    1997-01-01

    A set of analyses was conducted to determine the heat transfer characteristics of metallized gelled liquid propellants in a rocket engine. The analyses used the data from experiments conducted with a small 30- to 40-lbf thrust engine composed of a modular injector, igniter, chamber and nozzle. The fuels used were traditional liquid RP-1 and gelled RP-1 with 0-wt %, 5-wt%, and 55-wt% loadings of aluminum with silicon dioxide gellant, and gaseous oxygen as the oxidizer. Heat transfer was computed based on measurements using calorimeter rocket chamber and nozzle hardware with a total of 31 cooling channels. A gelled fuel coating formed in the 0-, 5- and 55-wt% engines, and the coating was composed of unburned gelled fuel and partially combusted RP-1. The coating caused a large decrease in calorimeter engine heat flux in the last half of the chamber for the 0- and 5-wt% RP-1/Al. This heat flux reduction effect was analyzed by comparing engine runs and the changes in the heat flux during a run as well as from run to run. Heat transfer and time-dependent heat flux analyses and interpretations are provided. The 5- and 55-wt% RP-1/Al fueled engines had the highest chamber heat fluxes, with the 5-wt% fuel having the highest throat flux. This result is counter to the predicted result, where the 55 wt% fuel has the highest combustion and throat temperature, and therefore implies that it would deliver the highest throat heat flux. The 5-wt% RP-1/Al produced the most influence on the engine heat transfer and the heat flux reduction was caused by the formation of a gelled propellant layer in the chamber and nozzle.

  13. Clinical studies with disposable diapers containing absorbent gelling materials: evaluation of effects on infant skin condition.

    PubMed

    Campbell, R L; Seymour, J L; Stone, L C; Milligan, M C

    1987-12-01

    Disposable infant diapers with absorbent gelling material (cross-linked sodium polyacrylates) incorporated into the core were clinically evaluated for their effect on infant skin condition. Absorbent gelling materials tightly hold water and provide pH control by a buffering capacity as well as by helping to segregate urine apart from feces. Four clinical studies were conducted with each following a rigid protocol that controlled for variables of diet and age in addition to the diaper material that may influence the development of diaper dermatitis and helped to control for any inherent bias in the study. This allowed for the controlled assessment of skin condition with respect to diaper type. Absorbent gelling material-containing disposable, conventional (100% cellulose core) disposable, and home-laundered cloth diapers were test products. In these studies 1614 infants were initially enrolled with 522 of them assigned to absorbent gelling material disposable, 738 to conventional disposable, and 354 to home-laundered cloth diapers. Objective measurements of skin wetness (transepidermal water loss) and skin pH, as well as double-blind grading of diaper dermatitis, were the measures of skin condition. Absorbent gelling material disposable diapers were associated with significantly reduced skin wetness, closer to normal skin pH, and lower degrees of diaper dermatitis when compared to conventional disposable or home-laundered cloth diapers. The results are consistent with the hypothesis that better control in the diaper area of skin wetness, skin pH, and the prevention of the mixing of urine and feces produces a better diaper environment.

  14. Formulation and Evaluation of Floating Oral In Situ Gelling System of Amoxicillin

    PubMed Central

    Patel, Dasharath M.; Patel, Divyesh K.; Patel, Chhagan N.

    2011-01-01

    Purpose. Effective Helicobacter pylori eradication requires delivery of the antibiotic locally in the stomach. High dose of amoxicillin (750 to 1000 mg) is difficult to incorporate in floating tablets but can easily be given in liquid dosage form. Keeping the above facts in mind, we made an attempt to develop a new floating in situ gelling system of amoxicillin with increased residence time using sodium alginate as gelling polymer to eradicate H. pylori. Methods. Floating in situ gelling formulations were prepared using sodium alginate, calcium chloride, sodium citrate, hydroxypropyl methyl cellulose K100, and sodium bicarbonate. The prepared formulations were evaluated for solution viscosity, floating lag time, total floating time, and in vitro drug release. The formulation was optimized using a 32 full factorial design. Dissolution data were fitted to various models to ascertain kinetic of drug release. Regression analysis and analysis of variance were performed for dependent variables. Results. All formulations (F1–F9) showed floating within 30 s and had total floating time of more than 24 h. All the formulations showed good pourability. It was observed that concentration of sodium alginate and HPMC K100 had significant influence on floating lag time, cumulative percentage drug release in 6 h and 10 h. The batch F8 was considered optimum since it showed more similarity in drug release (f2 = 74.38) to the theoretical release profile. Conclusion. Floating in situ gelling system of amoxicillin can be formulated using sodium alginate as a gelling polymer to sustain the drug release for 10 to 12 h with zero-order release kinetics. PMID:22389849

  15. Significance of heat-moisture treatment conditions on the pasting and gelling behaviour of various starch-rich cereal and pseudocereal flours.

    PubMed

    Collar, Concha

    2017-10-01

    The impact of heat-moisture treatment processing conditions (15%, 25%, and 35% moisture content; 1, 3, and 5 h heating time at 120 ℃) on the viscosity pasting and gelling profiles of different grain flours matrices (barley, buckwheat, sorghum, high β-glucan barley, and wheat) was investigated by applying successive cooking and cooling cycles to rapid visco analyser canisters with highly hydrated samples (3.5:25, w:w). At a milder heat-moisture treatment conditions (15% moisture content, 1 h heating time), except for sorghum, heat-moisture treatment flours reached much higher viscosity values during earlier pasting and subsequent gelling than the corresponding native counterparts. Besides heat-moisture treatment wheat flour, the described behaviour found also for non-wheat-treated flours has not been previously reported in the literature. An increased hydrophobicity of prolamins and glutelins in low moisture-short heating time heat-moisture treatment of non-wheat flours with high protein content (12.92%-19.95%) could explain the enhanced viscosity profile observed.

  16. Addressing the need for rapid treatment of agitation in schizophrenia and bipolar disorder: focus on inhaled loxapine as an alternative to injectable agents

    PubMed Central

    Citrome, Leslie

    2013-01-01

    Agitation (excessive motor or verbal activity) can be associated with schizophrenia or bipolar mania, and can further escalate into aggressive behavior and potentially lead to injuries in patients and staff. Medications used to treat agitation include antipsychotics and benzodiazepines, usually administered intramuscularly when rapid action is desired. Loxapine, a first-generation antipsychotic, has recently been reformulated into an inhaled powder that allows for direct administration to the lungs, resulting in rapid absorption into the systemic circulation. Administered via a single-use device, inhaled loxapine was tested in randomized controlled trials in agitation associated with schizophrenia or bipolar mania; doses of 5 mg and 10 mg were found to be efficacious, with an apparent dose response. In the Phase III studies, number needed to treat versus placebo for a ≥40% reduction from baseline on the Positive and Negative Syndrome Scale – Excited Component (PANSS-EC) at 2 hours was three for patients with bipolar disorder, and five for 5 mg and four for 10 mg for patients with schizophrenia, with effect sizes comparable to what has been observed in analogous studies of intramuscular injection of antipsychotics or lorazepam. Separation from placebo on the PANSS-EC was as early as 10 minutes postinhalation, the first time point where this was measured. Dysgeusia was the most commonly encountered spontaneously reported adverse event. Adverse events related to extrapyramidal symptoms and akathisia were relatively rare. Spirometry studies identified the potential for bronchospasm particularly in persons with asthma. Because of concerns over pulmonary safety, inhaled loxapine is restricted to use in hospitals and patients need to be prescreened for the presence of pulmonary disease, as well as monitored for signs and symptoms of bronchospasm for 1 hour postdose administration, as per a Food and Drug Administration-mandated Risk Evaluation and Mitigation Strategy

  17. Rapid determination of plutonium isotopes in environmental samples using sequential injection extraction chromatography and detection by inductively coupled plasma mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2009-10-01

    This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed by detection of isolated analytes with inductively coupled plasma mass spectrometry (ICP-MS). The method has been devised for the determination of Pu isotopes at environmentally relevant concentrations, whereby it has been successfully applied to the analyses of large volumes/amounts of samples, for example, 100-200 g of soil and sediment, 20 g of seaweed, and 200 L of seawater following analyte preconcentration. The investigation of the separation capability of the assembled SI system revealed that up to 200 g of soil or sediment can be treated using a column containing about 0.70 g of TEVA resin. The analytical results of Pu isotopes in the reference materials showed good agreement with the certified or reference values at the 0.05 significance level. Chemical yields of Pu ranged from 80 to 105%, and the decontamination factors for uranium, thorium, mercury and lead were all above 10(4). The duration of the in-line extraction chromatographic run was <1.5 h, and the proposed setup was able to handle up to 20 samples (14 mL each) in a fully automated mode using a single chromatographic column. The SI manifold is thus suitable for rapid and automated determination of Pu isotopes in environmental risk assessment and emergency preparedness scenarios.

  18. Cyclo-Aliphatic Epoxide Based Photo Cured Gelled Electrolytes for Secondary Li Battery Applications. Electrochemical Kinetic Studies

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Surampudi, S.; Halpert, G.

    1993-01-01

    Cyclo aliphatic epoxide based thin gelled fils prepared by UV photo curing were characterized electrochemically. Thylene carbonate (EC) mixed with different organic liquids in different volume ratios were used as solvents.

  19. Simple and rapid determination of thiabendazole, imazalil, and o-phenylphenol in citrus fruit using flow-injection electrospray ionization tandem mass spectrometry.

    PubMed

    Ito, Yuko; Goto, Tomomi; Oka, Hisao; Matsumoto, Hiroshi; Miyazaki, Yutaka; Takahashi, Nobuyuki; Nakazawa, Hiroyuki

    2003-02-12

    A simple and rapid analytical method for thiabendazole (TBZ), imazalil (IMA), and o-phenylphenol (OPP) in citrus fruit has been developed by using flow-injection electrospray ionization tandem mass spectrometry for the first time. The method involves the combined use of stable isotopically labeled internal standards (thiabendazole-(13)C(6), imazalil-d(5), and p-phenylphenol-d(9)) and a multiple reaction monitoring technique. The average recoveries for the fungicides at the tolerance levels (TBZ and OPP, 10 mg/kg; IMA, 5 mg/kg) ranged from 77 to 101%, with the coefficients of variation (CVs) ranging from 0.7 to 4.2% (n = 5). At half the tolerance levels (TBZ and OPP, 5 mg/kg; IMA, 2.5 mg/kg), the average recoveries ranged from 62 to 112%, with the CVs ranging from 0.7 to 8.4% (n = 5). The CVs of the average recoveries, obtained from lemon samples fortified with three fungicides at the tolerance levels, obtained on three different days over two weeks, ranged within 2%. The analysis time, including sample preparation and determination, is only 15 min.

  20. Rapid and simultaneous analysis of dichlorvos, malathion, carbaryl, and 2,4-dichlorophenoxy acetic acid in citrus fruit by flow-injection ion spray ionization tandem mass spectrometry.

    PubMed

    Nakazawa, Hiroyuki; Takahashi, Nobuyuki; Inoue, Koichi; Ito, Yuko; Goto, Tomomi; Kato, Kayoko; Yoshimura, Yoshihiro; Oka, Hisao

    2004-11-15

    A simple method for the rapid and simultaneous analysis of dichlorvos (DDVP), malathion, carbaryl, and 2,4-dichlorophenoxy acetic acid (2,4-D) in citrus fruit, which uses flow-injection ion spray ionization tandem mass spectrometry, has been developed for the first time. The method involves the combined use of stable isotopically labeled internal standards (DDVP-d(6), malathion-d(10), carbaryl-d(7), and 2,4-D-d(5)) and a multiple reaction monitoring technique. The average recoveries for the pesticides at the same concentrations as their tolerance levels (DDVP: 0.1-0.2mugg(-1); malathion: 0.5-4.0mugg(-1); carbaryl: 1.0mugg(-1); 2,4-D: 1.0-2.0mugg(-1)) ranged from 90 to 119% with the relative standard deviation (R.S.D.) ranging from 1.0 to 13.1% (n = 5). Analysis time, including sample preparation and determination, was only 15min. The present method is effective for screening DDVP, malathion, carbaryl, and 2,4-D in citrus fruit.

  1. Layered double hydroxides as an effective additive in polymer gelled electrolyte based dye-sensitized solar cells.

    PubMed

    Ho, Hsu-Wen; Cheng, Wei-Yun; Lo, Yu-Chun; Wei, Tzu-Chien; Lu, Shih-Yuan

    2014-10-22

    Layered double hydroxides (LDH), a class of anionic clay materials, were developed as an effective additive for polymer gelled electrolytes for use in dye-sensitized solar cells (DSSC). Carbonate and chloride intercalated Zn-Al LDHs, ZnAl-CO3 LDH, and ZnAl-Cl LDH were prepared with coprecipitation methods. The addition of the two LDHs significantly improved, in terms of power conversion efficiency (PCE), over the plain poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) gelled electrolyte and competed favorably with the liquid electrolyte based DSSCs, 8.13% for the liquid electrolyte, 7.48% for the plain PVDF-HFP gelled electrolyte, 8.11% for the ZnAl-CO3 LDH/PVDF-HFP gelled electrolyte, and 8.00% for the ZnAl-Cl LDH/PVDF-HFP gelled electrolyte based DSSCs. The good performance in PCEs achieved by the LDH-loaded DSSCs came mainly from the significant boost in open circuit voltages (Voc), from 0.74 V for both the liquid electrolyte and PVDF-HFP gelled electrolyte based DSSCs to 0.79 V for both the ZnAl-CO3 LDH/PVDF-HFP and ZnAl-Cl LDH/PVDF-HFP gelled electrolyte based DSSCs. The boost in Voc was contributed mainly by the positive shift in redox potential of the redox couple, I(-)/I3(-), as revealed from cyclic voltammetry analyses. As for the long-term stability, PCE retention rates of 96 and 99% after 504 h were achieved by the ZnAl-CO3 LDH/PVDF-HFP and ZnAl-Cl LDH/PVDF-HFP gelled electrolyte based DSSCs, respectively, appreciably better than 92% achieved by the liquid electrolyte based one after 480 h.

  2. Improving reservoir conformance using gelled polymer systems. Quarterly report, September 25--December 24, 1993

    SciTech Connect

    Green, D.W.; Willhite, G.P.; Buller, C.; McCool, S.; Vossoughi, S.; Michnick, M.

    1994-01-19

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems -- an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium(III)-polyacrylamide system and the aluminum citrate-polyacrylamide system. Laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Results to date are summarized.

  3. Gelling process of sodium alginate with bivalent ions rich microsphere: Nature of bivalent ions

    NASA Astrophysics Data System (ADS)

    Mauri, Marco; Vicini, Silvia; Castellano, Maila

    2016-05-01

    In the paper we present a new approach for obtaining a controlled gelling process of sodium alginate, based on the quantity of bivalent ions rich alginate micro-beads added as crosslinkers. Typically, calcium ions are used in gelation of alginate solutions. In this study we present different gelling systems realized with alginate microspheres, made by electrospinning methodology, enriched with different bivalent ions (Ca2+, Ba2+ and Mg2+). The microspheres were characterized under the point of view of the morphology by OM and as the ions content. Realized gels were characterized in light of the amount of the ions added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G″) and complex viscosity (η*).

  4. Correlation of the protein structure and gelling properties in dried egg white products.

    PubMed

    Handa, A; Hayashi, K; Shidara, H; Kuroda, N

    2001-08-01

    The relationship between protein structure and aggregation, as well as heat-induced gelling properties, of seven dried egg white (DEW) products was investigated. Strong correlations were found between average molecular weight and hydrophobicity plus surface SH groups of DEW-soluble protein aggregate (SPA). This suggests that hydrophobic interactions and disulfide bond formation between protein molecules were involved in the aggregation. The average molecular weight of DEW products with alkaline pHs was relatively higher than those with neutral pHs and the same degree of protein unfolding, probably because of more disulfide bond formation between protein molecules. In addition, strong correlations were found between hydrophobicity, surface SH groups plus average molecular weight of DEW-SPA, and physical properties of the gels from DEW products. These data indicated that controlling the aggregation of DEW proteins in the dry state is crucial to controlling the gelling properties of DEW.

  5. General Analytical Schemes for the Characterization of Pectin-Based Edible Gelled Systems

    PubMed Central

    Haghighi, Maryam; Rezaei, Karamatollah

    2012-01-01

    Pectin-based gelled systems have gained increasing attention for the design of newly developed food products. For this reason, the characterization of such formulas is a necessity in order to present scientific data and to introduce an appropriate finished product to the industry. Various analytical techniques are available for the evaluation of the systems formulated on the basis of pectin and the designed gel. In this paper, general analytical approaches for the characterization of pectin-based gelled systems were categorized into several subsections including physicochemical analysis, visual observation, textural/rheological measurement, microstructural image characterization, and psychorheological evaluation. Three-dimensional trials to assess correlations among microstructure, texture, and taste were also discussed. Practical examples of advanced objective techniques including experimental setups for small and large deformation rheological measurements and microstructural image analysis were presented in more details. PMID:22645484

  6. In situ permeability modification using gelled polymer systems. Annual report, April 11, 1997--April 10, 1998

    SciTech Connect

    Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.; Michnick, M.J.

    1998-09-01

    Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program focused on five areas: Gel treatment in fractured systems; Gel treatment in carbonate rocks; In-depth placement of gels; Gel systems for application in carbon dioxide flooding; and Gel treatment in production wells. The research program is primarily an experimental program directed toward improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the second 12 month period of a 28 month program is described.

  7. In situ permeability modification using gelled polymer systems. Topical report, June 10, 1996--April 10, 1997

    SciTech Connect

    Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.

    1997-10-01

    Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program is focused on five areas: gel treatment in fractured systems; gel treatment in carbonate rocks; in-depth placement of gels; gel systems for application in carbon dioxide flooding; and gel treatment in production wells. The research program is primarily an experimental program directed at improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the first 10 months of a 28 month program is described in the following sections.

  8. Stabilization of green bodies via sacrificial gelling agent during electrophoretic deposition

    DOEpatents

    Worsley, Marcus A.; Kuntz, Joshua D.; Rose, Klint A.

    2016-03-22

    In one embodiment, a method for electrophoretic deposition of a three-dimensionally patterned green body includes suspending a first material in a gelling agent above a patterned electrode of an electrophoretic deposition (EPD) chamber, and gelling the suspension while applying a first electric field to the suspension to cause desired patterning of the first material in a resulting gelation. In another embodiment, a ceramic, metal, or cermet includes a plurality of layers, wherein each layer includes a gradient in composition, microstructure, and/or density in an x-y plane oriented parallel to a plane of deposition of the plurality of layers along a predetermined distance in a z-direction perpendicular to the plane of deposition.

  9. Evaluations of diapers containing absorbent gelling material with conventional disposable diapers in newborn infants.

    PubMed

    Lane, A T; Rehder, P A; Helm, K

    1990-03-01

    We evaluated 149 infants diapered in either conventional cellulose core disposable diapers or diapers containing cellulose core with absorbent gelling material. The infants were evaluated from 1 day of age to 14 weeks of age for the prevalence and severity of diaper dermatitis. We identified a low prevalence of diaper dermatitis throughout the study period. At 14 weeks of age, we noted that infants in diapers containing absorbent gelling material had significantly less diaper dermatitis than those in conventional disposable diapers. Despite the overall low prevalence of diaper dermatitis in the newborn period, 7 of 204 infants evaluated had small skin erosions in the diaper area noted within the first 4 days of age. Both diaper types were associated with infants with erosions. This surprisingly high incidence of erosions in newborn infants suggests previously undocumented increased skin fragility of full-term infants.

  10. Shaping of gelling biopolymer drops in an elongation flow.

    PubMed

    Hamberg, Lars; Walkenström, Pernilla; Hermansson, Anne-Marie

    2002-08-15

    Shaping, defined as deformation in combination with gel formation of gelatine and kappa-carrageenan drops in an elongation flow, was studied. The focus was to investigate the possibility of shaping and fixating small drops in the diameter range 20 to 229 mum. In the shaping progress and the influence of experimental properties, the viscosity, temperature, and flow of the deforming fluid were examined on the final drop shape. In the experiments a hot emulsion of an aqueous biopolymer solution in silicone oil was injected into cold silicone oil where a deforming elongation flow field existed. After injection, a temperature decrease in the drops resulted in a gel formation of the biopolymer and a fixation of the deformed drop in the flow. The shape was measured and the effect on the drop aspect ratio was determined by image analysis. Over the total drop diameter range, kappa-carrageenan was more ellipsoid-shaped than gelatine, with a maximum aspect ratio of 6 compared to 4 for gelatine. For small drops, around 22 mum, it is possible to shape kappa-carrageenan, but for gelatine small drops tend to be unaffected. An increase in viscosity, temperature, and flow resulted in an increase in the final fixated shape of the drops. The differences in drop deformation between the biopolymers were explained by drop-viscosity/oil differences and differences in the kinetics of gel formation. The different gel formation kinetics resulted in a short, well-defined, shaping process for kappa-carrageenan, while for gelatine the process was more complex, with both deformation and relaxation present at different stages.

  11. Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments

    SciTech Connect

    Willhite, G.P.; Green, D.W.; McCool, C.S.

    2001-01-22

    This report describes the progress of the first year of a three-year research program. This program is aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production.

  12. Exact Gell-Mann-Low function of supersymmetric Kähler sigma models

    NASA Astrophysics Data System (ADS)

    Morozov, Alexei Y.; Perelomov, Askold M.; Shifman, Michael A.

    We consider a broad class of Kähler supersymmetric sigma models in two-dimensional space-time. The exact Gell-Mann-Low function is found within the framework of the method proposed earlier [1, 2] and based on analysis of classical solutions. It is shown that the exact beta function accounting for all orders in the coupling constant actually coincides with the one-loop result.

  13. Lubricant with gelling agent in treating dry eye in adult Chinese patients.

    PubMed

    Waduthantri, Samanthila; Yong, Siew Sian; Tan, Chien Hua; Htoon, Hla Myint; Tong, Louis

    2012-11-01

    To investigate the efficacy of a lubricant eye drop containing gelling agent in adult Chinese dry eye patients. This is a prospective, randomized, double-masked, double-arm, parallel, interventional single-site clinical study. Thirty Chinese dry eye patients were randomized into two arms, 15 patients each, receiving lubricant eye drops either containing hydroxypropyl-guar (HP-guar) gelling agent (Systane Ultra) or no gelling agent (Refresh Tears), 1 drop, four times a day for 6 weeks. The main outcome measure was global symptom score (based on severity and frequency of dry eye symptoms on a visual analog scale) at weeks 1, 3, and 6. Secondary outcomes were changes in sectoral corneal fluorescein staining, tear break-up time, and Schirmer's I test results from pretreatment level. Both groups showed significant improvement in symptoms from baseline (p < 0.001). There was no significant difference in the global symptom score at weeks 1, 3, and 6 between the two groups. There was significantly more severe corneal fluorescein staining in the HP-guar group at baseline in the left nasal (p = 0.023) and left inferior (p = 0.046) zones, but no difference in staining was observed between the two arms at weeks 1, 3, and 6. There were no differences in Schirmer's test results or tear break-up time (final and pretreatment) between the two groups (p > 0.05). Both lubricant eye drops, with or without HP-guar gelling agent, benefit patients in relieving dry eye symptoms. There was no difference in the efficacy of these drugs in terms of improving symptoms and altering objective signs of dry eye.

  14. The Erice Centre, Gell-Mann QCD, the Effective Energy and Complexity

    NASA Astrophysics Data System (ADS)

    Zichichi, A.

    2014-06-01

    On the occasion of the 80th Anniversary of Murray Gell-Mann I recalled the role played by Murray in those experimental and technological activities I had been directly involved during many years, which started in 1955 up to the time of the LHC supercollider, where we propose to study the Quark-Gluon-Coloured-World (QGCW), which is totally different from our world made of QCD colourless baryons and mesons...

  15. Improving reservoir conformance using gelled polymer systems. First quarterly report, September 25, 1992--December 24, 1992

    SciTech Connect

    Green, D.W.; Willhite, P.G.

    1992-12-25

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems -- an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by Cr(III) and an organic crosslinked system. Development of the KUSP1 system and evaluation and, identification of the organic crosslinked system will be conducted. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Progress report are presented for the following tasks: Development and selection of gelled polymer systems; physical and chemical characterization of gel systems; and mathematical modelling of gel systems.

  16. Improving reservoir conformance using gelled polymer systems. Second quarterly report, December 25, 1992--March 24, 1993

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1993-04-09

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems - an aqueous polysaccharide (KUSPI) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by CR(III) and an organic crosslinked system. Development of the KUSPI system and evaluation and identification of a suitable organic crosslinked system will be done. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Accomplishments for this period are presented for the following tasks: development and selection of gelled polymer systems, physical and chemical characterization of gel systems; and mathematical modeling of gel systems.

  17. Improving reservoir conformance using gelled polymer systems. Third quarterly report, March 25, 1993--June 24, 1993

    SciTech Connect

    Green, D.W.; Willhite, G.P.; Buller, C.; McCool, S.; Vossoughi, S.; Michnick, M.

    1993-07-01

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems - an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by CR(III) and an organic crosslinked system. Development of the KUSP1 system and evaluation and identification of a suitable organic crosslinked system will be done. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Accomplishments for this quarter are presented for the following tasks: development and selection of gelled polymer systems; physical and chemical characterization of gel systems; mechanism of in situ gelation; and mathematical modelling of gel systems.

  18. Improving reservoir conformance using gelled polymer systems. Sixth quarterly report, December 25, 1993--March 24, 1994

    SciTech Connect

    Green, D.W.; Willhite, G.P.; Buller, C.; McCool, S.; Vossoughi, S.; Michnick, M.

    1994-04-21

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems - an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium(III)-polyacrylamide system and the aluminum citrate-polyacrylamide system. Laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Accomplishments for this quarter are presented for the following tasks: development and selection of gelled polymer systems; and physical and chemical characterization of gel systems.

  19. Recycled paper products as substitutes for gelling agent in screwworm (Diptera: Calliphoridae) larval diet.

    PubMed

    Chaudhury, M F; Alvarez, L Alfredo; Velazquez, L Lopez

    2002-12-01

    Absorbent recycled paper products were tested and compared with a sodium polyacrylate gelling agent, Aquatain, for solidifying larval diets of the screwworm, Cochliomyia hominivorax (Coquerel). A recycled newsprint product, Terra-Mulch, when mixed with water and dietary ingredients produced a diet medium of homogeneous texture that supported larval growth and development comparable to the standard diet prepared with the gelling agent. Biological yields as calculated from number of pupae per tray from both the diets were similar. Three other types of recycled paper products were tested. Although less homogeneous in texture, these diets were as good as the diet with Terra-Mulch. There were no significant differences in the mean larval and pupal weights, no. of pupae/tray, percent emergence, oviposition, percent hatch, and percent longevity. When tests were conducted through eight consecutive generations, no adverse effect was noticed in any of the life history parameters. Terra-Mulch is inexpensive and biodegradable compared with the gelling agent Aquatain that is expensive and not biodegradable. Replacing Aquatain with Terra-Mulch in the screwworm larval diet for mass rearing may result in an annual savings of more than half a million U.S. dollars in costs of material and labor.

  20. New method for ophthalmic delivery of azithromycin by poloxamer/carbopol-based in situ gelling system.

    PubMed

    Cao, Feng; Zhang, Xiaolin; Ping, Qineng

    2010-01-01

    This study focused on preparation and evaluation of a thermosensitive and mucoadhesive in situ gelling ophthalmic system of azithromycin (ATM). Poloxamer 407 (P407) and poloxamer 188 (P188) were used as gelling agents. Addition of Carbopol 974P (CP 974P) to the gelling systems could increase the solubility of ATM by salt effect and enhance the mucoadhesive property of the systems. Gelation temperature of these systems ranged from 31.21-36.31 degrees C depending on the ratio of P407 and P188. Mucoadhesion force of the system composed of P407/P188/CP 974P (21/5/0.3%, w/v) was 2.3-fold that without carbopol 974P. Viscosity of the formulation was in a suitable range at 25 degrees C and pseudoplastic behavior was observed at 35 degrees C. The formulation exhibited a 24-h sustained release of ATM. In vivo resident experiments showed AUC(0-12) of ATM in rabbit tears increased by 1.78-fold for in situ gel compared with eye drop. At 12 h, tear concentrations exceeded minimum inhibitory concentration (MIC) breakpoint for the most common causative pathogens of bacterial conjunctivitis by 2.8-fold. Results in vitro and in vivo indicated that this droppable gel performed better than ATM eye drop did.

  1. New oil-gelling agents for cosmetics: formation mechanism of oil gels.

    PubMed

    Fukasawa, J; Tsutsumi, H; Ishida, A

    1989-08-01

    Summary New oil-gelling agents have been developed composed of a long-chain dialkyl phosphate (DP) surfactant and aluminium ion or multinuclear aluminum ion (MAI) which provide good oil-gel systems. One such gelling agent is the aluminum salt of DP (DP-Al) prepared as a precipitate by mixing DP with aluminum chloride in aqueous solutions. Addition of small amounts of the salt to non-polar oils led to hardening of the oil solutions at temperature below the melting point of the alkyl chain (Tc) of DP-Al. Results obtained by X-ray diffraction techniques and with scanning electron microscopy (SEM) revealed that linearly-polymerized assemblies of DP-Al expand in oils three-dimensionally, which suggests that the excellent stability of the gel systems arises from the highly ordered structure. The gelling agent of DP-Al offered the ideal rheological property to waxy cosmetic products such as lipsticks. The complexes of DP with MAI particles (1 nm diameter) of aluminum chlorohydrate, Al(13)O(4)(OH)(24)(H(2)O)(12)CI(7), provided the ideal thixotropic behaviour in non-polar oils. The DP-MAI particle complexes were found to interact weakly by cohesive forces which makes a highly ordered structure of the DP-MAI particle complexes. The DP-MAI particle complexes gave excellent stability and transparency to cosmetic products such as w/o creams.

  2. Gelled membranes for Li and Li-ion batteries prepared by electrospinning

    NASA Astrophysics Data System (ADS)

    Bansal, D.; Meyer, B.; Salomon, M.

    Composite polymer gelled membranes have been prepared an electrospinning technique. Electrospinning of polymer fibers or electrospraying of particles is typically accomplished by applying a strong electric field (ca. 1-25 kV cm -1) to a polymer solution or slurry of solids in an appropriate solvent. The fibers are collected as a mat (membrane) on a grounded target such as Al, Cu, Ni, etc. Typical membranes (mats) consist of nanometer size fibers and have porosities of 65-85%. In the present paper, we describe the fabrication of electrospun membranes for use as gelled electrolytes in Li and Li-ion batteries. The electrospun polymer membranes used in this work are based on the polyimides (PIs) Matrimid and Ultem 1000. Pure PI membranes have been prepared, and blends of Matrimid and Ultem with PVdF-HFP and PAN have been studied in 250 mAh and 7 Ah Li-ion cells. Fully imidized polyimides such as Matrimid and Ultem 1000 do not form gels, and are used as a host matrix of high mechanical strength to immobilize the gelling constituents PVdF or PAN.

  3. [Rapid screening and quality evaluation for the harmful substance 5-hydroxymethyl furfural in commercially available traditional Chinese medicine injection using LC-MS/MS method].

    PubMed

    Zang, Qing-ce; He, Jing-jing; Bai, Jin-fa; Zheng, Ya-jie; Zhang, Rui-ping; Li, Tie-gang; Wang, Zhong-hua; He, Jiu-ming; Abliz, Zeper

    2013-11-01

    To screen the harmful substance 5-hydroxymethyl furfural content in commercially available traditional Chinese medicine injection which are commonly used, and to preliminarily evaluate the quality of these injections, 5-hydroxymethyl furfural was taken as an index. The contents of 5-hydroxymethyl furfural in 56 samples which consist of 23 kinds of traditional Chinese medicine injections and glucose injection were determined using LC-MS/MS, and 5-hydroxymethyl furfural was detected in 52 of these samples. The minimal content was 0.0038 microg x L(-1) and the maximum content was 1420 microg x mL(-1). The contents of 5-hydroxymethyl furfural were significantly different in traditional Chinese medicine injection which came from different kinds, manufacturers or batches. The results showed the quality difference of commercially available traditional Chinese medicine injection is significant taking 5-hydroxymethyl furfural content as assessment index. More attention should be paid to the safety of 5-hydroxymethyl furfural in traditional Chinese medicine injection, and unified limitation standard should be set to improve medication safety of traditional Chinese medicine injection.

  4. Formulation and evaluation of microemulsion-based in situ ion-sensitive gelling systems for intranasal administration of curcumin.

    PubMed

    Wang, Shuang; Chen, Ping; Zhang, Lin; Yang, Chunfen; Zhai, Guangxi

    2012-12-01

    The purpose of our study was to develop a microemulsion-based in situ ion-sensitive gelling system for intranasal administration of curcumin. A new microemulsion composition for curcumin was optimized with the simple lattice design. And the microemulsion-based in situ ion-sensitive gelling system consisted of Capryol 90 as oil phase, Solutol HS15 as surfactant, Transcutol HP as cosurfactant and 0.3% DGG solution as water phase. The physicochemical properties such as morphology, droplet size distribution, zeta value and the in vitro release were investigated. In addition, the histological section studies on the reaction between the obtained formulation and nasal mucosa showed that the microemulsion-based in situ ion-sensitive gelling system could not produce obvious damage to nasal mucosa. The pharmacokinetics results showed that the absolute bioavailability of curcumin in the microemulsion-based in situ ion-sensitive gelling system was 55.82% by intranasal administration. And the brain targeting index (BTI) was 6.50, and in the tissue distribution experiment, the value of (AUC(brain)/AUC(blood)) following intranasal administration was higher than that following intravenous administration, suggesting that the obvious brain targeting property by nasal delivery be attributed to a direct nose-to-brain drug transport. It can be concluded that the microemulsion-based in situ gelling as an effective and safe vehicle could greatly enhance the in vivo absorption and facilitate the delivery of curcumin to brain by intranasal administration.

  5. Characteristics of a gelled liquid hyprogen polyphenylene oxide (PPO) foam open-cell insulation system, phase 1

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A large scale gel production and storage facility and a small scale facility, the latter used for detailed visual examination of the gel/PPO foam interface, were developed. A subcontract was given to investigate techniques for the production of gelled liquid hydrogen, develop a process design for scale-up to a 1.89 cu m (500 gallon) gel production and storage facility, determine gel transfer characteristics, determine the solubility rate of gaseous helium in the gel, and investigate the gross gel/PPO foam interfacial phenomena. An inside-tank process for scaled-up production of gelled liquid hydrogen was selected. No detectable gel structure degradation occurred during repeated shearing. The viscosity of gelled liquid hydrogen at shear rates of 300/sec and higher is 2 to 5-fold greater than that of neat liquid hydrogen. No clogging problems were encountered during the transfer of gelled liquid hydrogen through warmed transfer lines. The solubility rate of helium in liquid hydrogen was significantly reduced by the presence of gel structure. The boil-off rates from gelled liquid hydrogen were reduced from 25 to 50 percent compared to those observed for the neat liquid hydrogen under compatible conditions. The polyphenylene oxide (PPO) foam insulation was found to be compatible with liquid ethane.

  6. A Semi-Analytical Method for Rapid Estimation of Near-Well Saturation, Temperature, Pressure and Stress in Non-Isothermal CO2 Injection

    NASA Astrophysics Data System (ADS)

    LaForce, T.; Ennis-King, J.; Paterson, L.

    2015-12-01

    Reservoir cooling near the wellbore is expected when fluids are injected into a reservoir or aquifer in CO2 storage, enhanced oil or gas recovery, enhanced geothermal systems, and water injection for disposal. Ignoring thermal effects near the well can lead to under-prediction of changes in reservoir pressure and stress due to competition between increased pressure and contraction of the rock in the cooled near-well region. In this work a previously developed semi-analytical model for immiscible, nonisothermal fluid injection is generalised to include partitioning of components between two phases. Advection-dominated radial flow is assumed so that the coupled two-phase flow and thermal conservation laws can be solved analytically. The temperature and saturation profiles are used to find the increase in reservoir pressure, tangential, and radial stress near the wellbore in a semi-analytical, forward-coupled model. Saturation, temperature, pressure, and stress profiles are found for parameters representative of several CO2 storage demonstration projects around the world. General results on maximum injection rates vs depth for common reservoir parameters are also presented. Prior to drilling an injection well there is often little information about the properties that will determine the injection rate that can be achieved without exceeding fracture pressure, yet injection rate and pressure are key parameters in well design and placement decisions. Analytical solutions to simplified models such as these can quickly provide order of magnitude estimates for flow and stress near the well based on a range of likely parameters.

  7. Exact Gell-Mann-Low function of supersymmetric Kähler σ-models (II)

    NASA Astrophysics Data System (ADS)

    Perelomov, A. M.; Prati, M. C.

    We extend the analysis carried out in [1] to a new class of Kähler supersymmetric σ-models in the two-dimensional space-time. Here the fields take values in the flag space F n, n = 1, 2 … and there are n topological charges. It turns out that also for these models the Gell-Mann-Low β-function to all orders coincides with the one-loop approximation, for which we calculate explicitly the exact value of the multiplicative constant.

  8. Hydroponics gel as a new electrolyte gelling agent for alkaline zinc-air cells

    NASA Astrophysics Data System (ADS)

    Othman, R.; Basirun, W. J.; Yahaya, A. H.; Arof, A. K.

    The viability of hydroponics gel as a new alkaline electrolyte gelling agent is investigated. Zinc-air cells are fabricated employing 12 wt.% KOH electrolyte immobilised with hydroponics gel. The cells are discharged at constant currents of 5, 50 and 100 mA. XRD and SEM analysis of the anode plates after discharge show that the failure mode is due to the formation of zinc oxide insulating layers and not due to any side reactions between the gel and the plate or the electrolyte.

  9. A Green Antioxidant Activity-Integrated Dual-Standard Method for Rapid Evaluation of the Quality of Traditional Chinese Medicine Xuebijing Injection by On-Line DPPH-CE-DAD

    PubMed Central

    Li, Jin; Liu, Jiao; Liu, Wei; Yu, Xie-an; An, Mingrui; Gao, Xiu-mei

    2016-01-01

    Much attention has been focused on treatment of sepsis which leads to high mortality all over the world in every year. Antioxidant activity seems to play a prominent role in the treatment of sepsis exhibited by Xuebijing injection. The aim of the present research was to develop an on-line 1, 1-diphenyl-2-picrylhydrazyl- (DPPH-) capillary electrophoresis-diode array detector (on-line DPPH-CE-DAD) method for rapidly assessing antioxidant properties and efficacious material basis of antioxidant activity as a way of quality control of Xuebijing injection. Several parameters affecting the separation were investigated, including the pH and concentrations of buffer, SDS, β-CD, and organic modifier as well as voltage and cassette temperature. Compared to previous traditional method, this improved method shortened the experimental cycle and became more efficient because it was successfully applied to analyze total antioxidant activity and contents of twelve antioxidants of Xuebijing injection under the same condition. The results revealed that the on-line DPPH-CE-DAD method was a reagent-saving, rapid, feasible, and green technique for quality control of Xuebijing injection in terms of pharmacological activity and contents of active ingredients. It also offered new opportunities for the analysis of antioxidant activity of complex matrix. PMID:27872649

  10. A scintigraphic investigation of the disintegration behaviour of capsules in fasting subjects: a comparison of hypromellose capsules containing carrageenan as a gelling agent and standard gelatin capsules.

    PubMed

    Tuleu, C; Khela, M K; Evans, D F; Jones, B E; Nagata, S; Basit, A W

    2007-03-01

    Two-piece hard shell capsules made from hypromellose (or hydroxypropyl methylcellulose, HPMC) have been proposed as an alternative to conventional gelatin capsules for oral drug delivery; however, little is known about their in vivo behaviour. The aim of this study was to compare the disintegration of HPMC and gelatin capsules in fasted human subjects using the technique of gamma scintigraphy. HPMC capsules containing carrageenan as a gelling agent (QUALI-V(R), Qualicaps) and gelatin capsules (Qualicaps) of size 0 were filled with a lactose-based mixture. The capsules were separately radiolabelled with indium-111 and technetium-99m. Both capsules were administered simultaneously with 180ml water to eight healthy male subjects following an overnight fast. Each volunteer was positioned in front of the gamma camera and sequential 60s images were acquired in a continuous manner for 30min. No differences in the oesophageal transit of the two types of capsules were noted, with the capsules arriving in the stomach in a matter of seconds. All the capsules disintegrated in the stomach. The mean (+/-S.D.) disintegration time for the HPMC capsules was 9+/-2min (range 6-11min). The corresponding mean time for the gelatin capsules was 7+/-4min (range 3-13min). These disintegration times were not significantly different (P=0.108, paired t-test). In conclusion, HPMC and gelatin capsules show rapid and comparable in vivo disintegration times in the fasted state. HPMC capsules containing carrageenan as a gelling agent therefore offer a practical alternative to gelatin capsules as an oral drug delivery carrier.

  11. Injectable Chitosan/β-Glycerophosphate System for Sustained Release: Gelation Study, Structural Investigation, and Erosion Tests.

    PubMed

    Dalmoro, Annalisa; Abrami, Michela; Galzerano, Barbara; Bochicchio, Sabrina; Barba, Anna Angela; Grassi, Mario; Larobina, Domenico

    2017-01-01

    Hydrogels can constitute reliable delivery systems of drugs, including those based on nucleic acids (NABDs) such as small interfering ribonucleic acid (siRNA). Their nature, structure, and response to physiological or external stimuli strongly influence the delivery mechanisms of entrapped active molecules, and, in turn, their possible uses in pharmacological and biomedical applications. In this study, a thermo-gelling chitosan/β-glycero-phosphate system has been optimized in order to assess its use as injectable system able to: i) gelling at physiological pH and temperature, and ii) modulate the release of included active ingredients. To this aim, we first analyzed the effect of acetic acid concentration on the gelation temperature. We then found the "optimized composition", namely, the one in which the Tgel is equal to the physiological temperature. The resulting gel was tested, by low field nuclear magnetic resonance (LF-NMR), to evaluate its average mesh-size, which can affect release kinetics of loaded drug. Finally, films of gelled chitosan, loaded with a model drug, have been tested in vitro to monitor their characteristic times, i.e. diffusion and erosion time, when they are exposed to a medium mimicking a physiological environment (buffer solution at pH 7.4). Results display that the optimized system is deemed to be an ideal candidate as injectable gelling material for a sustained release. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Etanercept Injection

    MedlinePlus

    ... injection comes as a solution (liquid) in a prefilled syringe and an automatic injection device, and as a ... etanercept injection.If your medication comes in a prefilled syringe or automatic injection device, use each syringe or ...

  13. Design and characterization of a novel amphiphilic chitosan nanocapsule-based thermo-gelling biogel with sustained in vivo release of the hydrophilic anti-epilepsy drug ethosuximide.

    PubMed

    Hsiao, Meng-Hsuan; Larsson, Mikael; Larsson, Anette; Evenbratt, Hanne; Chen, Ying-Yu; Chen, You-Yin; Liu, Dean-Mo

    2012-08-10

    Thermo-gelling injectable nanogels, with no burst release of loaded drug, were prepared by a simple route by combining self assembled nanocapsules of amphiphilically modified chitosan with glycerophosphate di-sodium salt and glycerol. The potential as a depot drug delivery system was demonstrated in vivo through the therapeutic effect of ethosuximide (ESM) loaded nanogels, suppressing spike wave discharges (SWDs) in Long Evan rat model. Simultaneously clearance of gels from the site of administration was monitored non-invasively using MRI. The gel structure was characterized using TEM and SEM, confirming the gels to be an assembly of nanocapsules and using two-photon microscopy to visualize the network structure. In vitro drug release studies using ESM revealed that the nanogels exhibited extended, mostly Fickian release. Finally, all investigated formulations displayed excellent cytotoxicity data determined by MTT assay using human retinal pigmented epithelium cells. All presented properties are highly desirable for injectable depot gels for drug delivery. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Effects of gelling bath on the physical properties of alginate gel beads and the biological characteristics of entrapped HepG2 cells.

    PubMed

    Sun, Dongsheng; Liu, Yang; Wu, Hao; Ren, Ying; Ma, Xiaojun; Wu, Huijian; Sun, Guangwei

    2017-08-09

    Optimizing alginate gel beads is necessary to support the survival, proliferation, and function of entrapped hepatocytes. In this study, gelling bath was modified by decreasing calcium ion concentration and increasing sodium ion concentration. Alginate gel beads (using 36% G sodium alginate) prepared in the modified gelling bath had more homogeneous structure and better mass transfer properties compared with the traditional gelling bath that contains only calcium ions. Moreover, alginate gel beads generated in the modified gelling bath could significantly promote the HepG2 cell proliferation and the growth of cell spheroids, and maintain the albumin secretion ability similar to alginate gel beads prepared in the traditional gelling bath with only calcium ions. The mass transfer properties and cell proliferation were similar in ALG beads with different M/G ratio (36% G and 55% G) generated in the modified gelling bath, whereas they were significantly increased compared with alginate gel beads (55% G) in traditional gelling bath. These results indicated that adjusting the gelling bath was a simple and convenient method to enhance the mass transfer properties of alginate gel beads for 3D hepatocyte culture, which might provide more hepatocytes for the bioartificial liver support system. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

  15. The Gell-Mann - Okubo Mass Relation among Baryons from Fully-Dynamical, Mixed-Action Lattice QCD

    SciTech Connect

    Konstantinos Orginos; Silas Beane; Martin Savage

    2007-10-01

    We explore the Gell-Mann - Okubo mass relation among the octet baryons using fully-dynamical, mixed-action (domain-wall on rooted-staggered) lattice QCD calculations at a lattice spacing of b {approx} 0.125 fm and pion masses of m{sub pi} {approx} 290 MeV, 350 MeV, 490 MeV and 590 MeV. Deviations from the Gell-Mann - Okubo mass relation are found to be small at each quark mass.

  16. Thiolated poly(aspartic acid) as potential in situ gelling, ocular mucoadhesive drug delivery system.

    PubMed

    Horvát, Gabriella; Gyarmati, Benjámin; Berkó, Szilvia; Szabó-Révész, Piroska; Szilágyi, Barnabás Áron; Szilágyi, András; Soós, Judit; Sandri, Giuseppina; Bonferoni, Maria Cristina; Rossi, Silvia; Ferrari, Franca; Caramella, Carla; Csányi, Erzsébet; Budai-Szűcs, Mária

    2015-01-25

    The ophthalmic formulations on the market suffer from poor bioavailability, and it would therefore be useful to design a new formulation which is able to prolong the residence time and reduce the administration frequency. Polymer matrices which exhibit strong mucoadhesion are promising platforms in ocular drug delivery from the aspect of improved bioavailability. In the present study, an in situ gelling, mucoadhesive drug delivery system was fabricated from thiolated poly(aspartic acid) (ThioPASP). The thiol groups of ThioPASP are able to form disulphide linkages with the mucin glycoproteins and prolong the residence time on the eye. The effects of the thiol groups on the structure, swelling behaviour and mucoadhesive character of the gel and on the drug release profile were determined. The gel structure was characterized by means of rheology. The ThioPASP gel was demonstrated by rheology, tensile test and 'wash away' measurements to display strong mucoadhesion. The drug release from the ThioPASP gel was studied on a vertical Franz diffusion cell: a burst release of sodium diclofenac occurred in the first hour, followed by sustained release of the encapsulated drug for up to 24h. The results proved the importance of the presence of the thiol groups and suggested that a ThioPASP formulation can be useful as an in situ gelling, ocular dosage form. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Improving reservoir conformance using gelled polymer systems. Eleventh quarterly report, April 1, 1995--June 30, 1995

    SciTech Connect

    Green, D.W.; Willhite, G.P.; Buller, C.; McCool, S.; Vossoughi, S.; Michnick, M.

    1995-07-24

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems -- an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium(III)-polyacrylamide system and the aluminum citrate-polyacrylamide system. Laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Technical progress is described for the following tasks: physical and chemical characterization of gel systems; mechanisms of in situ gelation; and mathematical modelling of the gel systems.

  18. Use of olive oil-in-water gelled emulsions in model turkey breast emulsions

    NASA Astrophysics Data System (ADS)

    Serdaroğlu, M.; Öztürk, B.

    2017-09-01

    Today, gelled emulsion systems offer a novel possibility in lipid modification of meat products. In this study, we aimed to investigate the quality characteristics of model turkey emulsions that were prepared with olive oil-in-water gelled emulsion (GE) as partial or total beef fat replacer. The results indicated that while most of the GE treatments showed equivalent emulsion characteristics in terms of emulsion stability, water-holding capacity and cook yield, utilization of 100% GE as the lipid source could increase total expressible fluid of the model turkey emulsion and thus negatively affect the quality. Utilization of GE was effective in total fat reduction, as the model turkey emulsions formulated with more than 50% GE had significantly lower fat content compared to full-beef fat control model emulsion. However, beef fat replacement with GE produced considerable changes in colour parameters. Finally, it was concluded that utilization of GE as a partial beef fat replacer has good potential to enhance stability and reduce total fat in turkey meat emulsion products.

  19. Nanosuspension based in situ gelling nasal spray of carvedilol: development, in vitro and in vivo characterization.

    PubMed

    Saindane, Nilesh S; Pagar, Kunal P; Vavia, Pradeep R

    2013-03-01

    The objective of the present investigation was to develop in situ gelling nasal spray formulation of carvedilol (CRV) nanosuspension to improve the bioavailability and therapeutic efficiency. Solvent precipitation-ultrasonication method was opted for the preparation of CRV nanosuspension which further incorporated into the in situ gelling polymer phase. Optimized formulation was extensively characterized for various physical parameters like in situ gelation, rheological properties and in vitro drug release. Formation of in situ gel upon contact with nasal fluid was conferred via the use of ion-activated gellan gum as carrier. In vivo studies in rabbits were performed comparing the nasal bioavailability of CRV after oral, nasal, and intravenous administration. Optimized CRV nanosuspension prepared by combination of poloxamer 407 and oleic acid showed good particle size [d (0.9); 0.19 μm], zeta potential (+10.2 mV) and polydispersity (span; 0.63). The formulation containing 0.5% w/v gellan gum demonstrated good gelation ability and desired sustained drug release over period of 12 h. In vivo pharmacokinetic study revealed that the absolute bioavailability of in situ nasal spray formulation (69.38%) was significantly increased as compared to orally administered CRV (25.96%) with mean residence time 8.65 h. Hence, such in situ gel system containing drug nanosuspension is a promising approach for the intranasal delivery in order to increase nasal mucosal permeability and in vivo residence time which altogether improves drug bioavailability.

  20. Formulation and characterization of radio-opaque conjugated in situ gelling materials.

    PubMed

    Blakely, Brandon; Hoon Lee, Bae; Riley, Celeste; McLemore, Ryan; Pathak, Chandrashekhar P; Vernon, Brent L

    2010-04-01

    X-ray visibility is an integral design component of in situ gelling embolization systems for neurovascular treatment. The goals of this project included the synthesis and characterization of a unique intrinsically radio-opaque in situ gelling material for neurovascular embolization. The gels formed using Michael-Type Addition between pentaerythritol tetrakis 3-mercaptopropionate (QT) thiols and poly(propylene glycol) diacrylate (PPODA) with the addition of the new material Iodobenzoyl poly(ethylene glycol) acrylate (IPEGA), a radio-opaque agent, synthesized successfully as confirmed with (1)H NMR. The PPODA and IPEGA were mixed using a syringe coupler with QT and buffer at pH 11 for 90 seconds. Gel mixes were weighed to provide equal molar thiols and acrylate groups, changing the present acrylate-bearing compounds wt % ratios from 100 PPODA: 0 IPEGA, 90:10, 80:20, 70:30, 60:40, 50:50, and 0:100. Formulations with 10% and above of IPEGA were X-ray visible. Rheology showed that increasing the amount of IPEGA decreased the storage. Kinetic FT-IR studies indicate that the amphiphilic nature of the PEG backbone increased the reaction rate of the phase segregated reactants. Second order reaction constant modeling showed a change in initial reaction rate from 0.0029 to 0.0187 (M sec)(-1) from the 10% to 50% IPEGA formulations respectively.

  1. Improving reservoir conformance using gelled polymer systems. Quarterly progress report, July 1--September 30, 1994

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1994-11-01

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems an aqueous polysaccharide (KUSP 1) system that gels as a function of pH, the chromium(III)-polyacrylamide system and the aluminum citratepolyacrylamide system. Laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Technical progress is described for three studies: Physical and chemical characterization of gel systems (chemical reaction kinetics of KUSP1); Mechanisms of in situ gelation; and Mathematical modeling of gel systems.

  2. Extraction, characterization and gelling behavior enhancement of pectins from the cladodes of Opuntia ficus indica.

    PubMed

    Lefsih, Khalef; Delattre, Cédric; Pierre, Guillaume; Michaud, Philippe; Aminabhavi, Tejraj M; Dahmoune, Farid; Madani, Khodir

    2016-01-01

    Total Pectins Fraction (TPF) was extracted at room temperature from dried cladodes of Opuntia ficus indica. TPF is constituted of three pectic fractions WSP, CSP and ASP, which are made up of 66.6%, 44.3% and 81.1% (w/w) of galacturonic acid, respectively. The antioxidant ability of TPF increased with the concentration increasing. It scavenged hydroxyl radical by 90% and chelated 90% of ferrous ions at 5 g/L. FTIR study was carried out. Strong characteristic absorption peaks at 1,618 cm(-1) assigned to the vibration of COO(-) group of galacturonic acid. In the fingerprint region, we noticed three well-defined peaks at 1054, 1085, and 1,154 cm(-1) characteristic of pectic polysaccharides. TPF are non-gelling pectins. The co-crosslinking of TPF with carrageenan was carried out and the gelling behavior was successfully improved. Thermo-sensitive hydrogel was obtained with 82% of TPF and 18% of carrageenan (w/w). Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Self-cross-linking biopolymers as injectable in situ forming biodegradable scaffolds.

    PubMed

    Balakrishnan, Biji; Jayakrishnan, A

    2005-06-01

    The injectable polymer scaffolds which are biocompatible and biodegradable are important biomaterials for tissue engineering and drug delivery. Hydrogels derived from natural proteins and polysaccharides are ideal scaffolds for tissue engineering since they resemble the extracellular matrices of the tissue comprised of various amino acids and sugar-based macromolecules. Here, we report a new class of hydrogels derived from oxidized alginate and gelatin. We show that periodate-oxidized sodium alginate having appropriate molecular weight and degree of oxidation rapidly cross-links proteins such as gelatin in the presence of small concentrations of sodium tetraborate (borax) to give injectable systems for tissue engineering, drug delivery and other medical applications. The rapid gelation in the presence of borax is attributed to the slightly alkaline pH of the medium as well as the ability of borax to complex with hydroxyl groups of polysaccharides. The effect of degree of oxidation and concentration of alginate dialdehyde, gelatin and borax on the speed of gelation was examined. As a general rule, the gelling time decreased with increase in concentration of oxidized alginate, gelatin and borax and increase in the degree of oxidation of alginate. Cross-linking parameters of the gel matrix were studied by swelling measurements and trinitrobenzene sulphonic acid (TNBS) assay. In general, the degree of cross-linking was found to increase with increase in the degree of oxidation of alginate, whereas the swelling ratio and the degree of swelling decreased. The gel was found to be biocompatible and biodegradable. The potential of the system as an injectable drug delivery vehicle and as a tissue-engineering scaffold is demonstrated by using primaquine as a model drug and by encapsulation of hepatocytes inside the gel matrix, respectively.

  4. Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments, Annual Report, June 16,2000-June 15, 2001

    SciTech Connect

    Willhite, G.P.; Green, D.W.; McCool, C.S.

    2002-05-22

    This program was aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production.

  5. Time-ordered exponential on the complex plane and Gell-Mann—Low formula as a mathematical theorem

    SciTech Connect

    Futakuchi, Shinichiro; Usui, Kouta

    2016-04-15

    The time-ordered exponential representation of a complex time evolution operator in the interaction picture is studied. Using the complex time evolution, we prove the Gell-Mann—Low formula under certain abstract conditions, in mathematically rigorous manner. We apply the abstract results to quantum electrodynamics with cutoffs.

  6. Improving reservoir conformance using gelled polymer systems. Quarterly technical progress report, July 1, 1995--September 30, 1995

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1995-10-17

    Objectives of this project are to identify and develop gelled polymer systems which have potential to improve reservoir conformance to fluid displacement systems; determine the performance of these systems; and to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. Gels investigated include an aqueous polysaccharide, a chromium-polacrylamide, and an aluminium citrate-polyacrylamide system.

  7. Effect of seasonal changes on the gelling properties of farmed sea bass (Dicentrarchus labrax).

    PubMed

    Cardoso, Carlos L; Mendes, Rogério O; Vaz-Pires, Paulo; Nunes, Maria L

    2014-01-01

    The effect of seasonal changes (summer versus winter) upon the quality of heat-induced gel products from farmed sea bass (Dicentrarchus labrax) was studied. Moreover, the effect of microbial transglutaminase addition (0.5%, w/w) on the quality was assessed. Fat content of gel products attained from sea bass grown during summer was higher (12.0% versus 7.6%). Textural properties of the gels from the summer fish were higher. Protein of gels from winter fish was less soluble in SDS + DTT (sodium dodecyl sulphate, SDS; dithiothreitol, DTT). Contrary to some literature, higher fat level may have played a protective role during processing. Accordingly, season via fat content variation had a strong effect on the gelling ability of heat-induced gels prepared from sea bass.

  8. Oral sustained delivery of paracetamol from in situ-gelling gellan and sodium alginate formulations.

    PubMed

    Kubo, Wataru; Miyazaki, Shozo; Attwood, David

    2003-06-04

    The purpose of this study was to evaluate the potential for the oral sustained delivery of paracetamol of two formulations with in situ gelling properties. Oral administration of aqueous solutions of either gellan gum (1.0%, w/v) or sodium alginate (1.5%, w/v) containing calcium ions in complexed form resulted in the formation of gel depots in rabbit and rat stomachs as a consequence of the release of the calcium ions in the acidic environment. In vitro studies demonstrated diffusion-controlled release of paracetamol from the gels over a period of 6h. The bioavailability of paracetamol from the gels formed in situ in the stomachs of rabbits following oral administration of the liquid formulations was similar to that of a commercially available suspension containing an identical dose of paracetamol.

  9. Ion-activated in situ gelling systems for sustained ophthalmic delivery of ciprofloxacin hydrochloride.

    PubMed

    Balasubramaniam, J; Pandit, J K

    2003-01-01

    The poor bioavailability and therapeutic response exhibited by the conventional ophthalmic solutions due to precorneal elimination of the drug may be overcome by the use of in situ gel forming systems that are instilled as drops into the eye and undergo a sol-gel transition in the cul-de-sac. Our present work describes the formulation and evaluation of an ophthalmic delivery system of an antibacterial agent, CPH, based on the concept of ion-activated in situ gelation. Gelrite gellan gum, a novel ophthalmic vehicle that gels in the presence of mono or divalent cations, present in the lacrimal fluid was used alone and in combinations with sodium alginate as the gelling agent. The developed formulations were therapeutically efficacious and provided sustained release of the drug over an 8-hr period in vitro.

  10. Gelling process for sodium alginate: New technical approach by using calcium rich micro-spheres.

    PubMed

    Vicini, Silvia; Castellano, Maila; Mauri, Marco; Marsano, Enrico

    2015-12-10

    Alginate based materials have become an important class of products in many fields from the pharmaceutical industry to tissue engineering, because of their ability to create stimuli responsive hydrogels. We present a new technical approach for obtaining a controlled gelling process, based on the quantities of Ca(2+) rich alginate micro-beads added as crosslinkers. The gels have been evaluated in light of the amount of Ca(2+) added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G'') and complex viscosity (η(*)) as well as swelling and deswelling tests. The methodology was developed to obtain a material with specific characteristics for application in the field of conservation. The material had to be able to create a stable gel after being applied on the artwork surface and to confine the solvent action at the interface during cleaning operations.

  11. Characterization of sodium phenytoin co-gelled with titania for a controlled drug-release system

    SciTech Connect

    Lopez, T.; Quintana, P. . E-mail: pquint@mda.cinvestav.mx; Ortiz-Islas, E.; Vinogradova, E.; Manjarrez, J.; Aguilar, D.H.; Castillo-Ocampo, P.; Magana, C.

    2007-08-15

    Sodium phenytoin, C{sub 15}H{sub 11}N{sub 2}NaO{sub 2}, in several concentrations was co-gelled with titania (TiO{sub 2}), by a sol-gel process. This technique is a promising method to encapsulate several drugs, in this case, phenytoin is an anticonvulsant used to control epileptic seizures. Samples were prepared by adding different concentrations (X = 50, 100, 200 and 250 mg per 20 g of titania matrix) of sodium phenytoin (Ph) to a solution of titanium n-butoxide. The resulting titania-Ph-X materials were characterized by transmission electron microscopy (TEM), Fourier transformed infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and Brunauer-Emmet-Teller (BET) surface areas. The porous nanomaterials showed a wide range of particle size, from 10 to 210 nm, with a mean pore diameter of 5 nm. X-ray diffraction showed an amorphous structure of the prepared samples.

  12. Applications of Optical Sensors to the Detection of Light Scattered from Gelling Systems

    NASA Astrophysics Data System (ADS)

    Bulone, Donatella; Manno, Mauro; San Biagio, Pier Luigi; Martorana, Vincenzo

    Visible light, scattered within an angle of few degrees, (Small Angle Light Scattering, SALS) yields information on the spatial correlations and dynamical properties on the scale of the micrometers. In this way a quick and non-invasive characterization of a variety of samples is feasible. Lately the SALS instruments have been built around multielement optical sensors (CCD, CMOS), allowing the simultaneous measurement of the complete structure factor even during fast kinetics. An assessment of some sensor matrices of different technology will be presented. The omolecular assemblies produced by polysaccharides or proteins can be functional or dysfunctional, their properties being either desirable or detrimental. Anyhow, their morphology often depends, in a very delicate way, on the presence of cosolutes, on the thermal history, on the biopolymer concentration etc. We present some applications of low angle dynamic and static light scattering to the study of gelling systems (agarose, pectin, insulin).

  13. Pegfilgrastim Injection

    MedlinePlus

    Pegfilgrastim comes as a solution (liquid) in prefilled injection syringes and in a pre-filled automatic injection device (On-body Injector) to inject subcutaneously (under the skin). If you are using pegfilgrastim to ...

  14. Cabazitaxel Injection

    MedlinePlus

    ... injection is used along with prednisone to treat prostate cancer (cancer of a male reproductive organ) that has ... cabazitaxel injection is usually used in men with prostate cancer. If used by pregnant women, cabazitaxel injection can ...

  15. Ondansetron Injection

    MedlinePlus

    Zofran® Injection ... Ondansetron injection is used to prevent nausea and vomiting caused by cancer chemotherapy and surgery. Ondansetron is in a ... medications: or any of the ingredients in ondansetron injection. Ask your pharmacist for a list of the ...

  16. Retention of reversibly thermo-gelling timolol on the human ocular surface studied by video meniscometry.

    PubMed

    Ishibashi, Takeshi; Yokoi, Norihiko; Bron, Anthony J; Tiffany, John M; Komuro, Aoi; Kinoshita, Shigeru

    2003-08-01

    To investigate the retention of reversibly thermo-gelling timolol (TG-timolol) on the human ocular surface using video meniscometry. The study population consisted of 14 healthy volunteers with no external eye disease. Fifteen microl TG-timolol were instilled into one eye of each subject and the same volume of aqueous, timolol ophthalmic solution was instilled in the fellow eye, in a masked fashion. Tear meniscus curvature was monitored at the center of the lower meniscus in each eye, using a newly-developed video meniscometer, before and at one-minute intervals for ten minutes after, the instillation. The radius of meniscus curvature (R) was calculated from printed video-images using the concave mirror formula. The change in R with time after instillation was compared for the two groups. The change in meniscus radius with time t [defined as deltaR(t) = R(t) - R(0)] showed a significant exponential regression in both the TG-timolol and the timolol groups. There was a significant difference in the value of deltaR(5) and deltaR(10) between eyes with TG-timolol [deltaR(5) = 0.29 mm, deltaR(10) = 0.18mm] and eyes with timolol only [deltaR(5) = 0.10mm, deltaR(10) = 0.06 mm] [deltaR(5): P < 0.001, deltaR(10): P < 0.001]. The area under each regression curve of deltaR(t), an indicator of vehicle retention, was greater in the eyes treated with TG-timolol than in those receiving timolol only (2.09 vs. 0.56, P < 0.001). The present study demonstrated that the reversibly thermo-gelling timolol was better retained at the ocular surface than conventional, aqueous timolol.

  17. Nanospray technology for an in situ gelling nanoparticulate powder as a wound dressing.

    PubMed

    De Cicco, Felicetta; Porta, Amalia; Sansone, Francesca; Aquino, Rita P; Del Gaudio, Pasquale

    2014-10-01

    In the current study the feasibility of the novel nano spray drying technique for the production of stable nanoparticulate dry powder, able to gel when administered locally on a wound, is explored. Gentamicin sulphate (GS) was loaded into alginate/pectin nanoparticles as highly soluble (hygroscopic) model drug with wide range antibacterial agent for wound dressing. The influence of process variables, mainly spray mesh size and feed concentration, on particle size and morphology, powder wound fluid uptake ability and gelling rate, as well as hydrogel water vapour transmission at wound site were studied. Particles morphology was spherical with few exceptions as slightly corrugated particles when the larger nozzle was used. Production of spherical nanoparticles (d50 ∼ 350 nm) in good yield (82-92%) required 4 μm spray mesh whereas 7 μm mesh produced larger wrinkled particles. Nano spray-dried particles showed high encapsulation efficiency (∼ 80%), good flowability, high fluid uptake, fast gel formation (15 min) and proper adhesiveness to fill the wound site and to remove easily the formulation after use. Moreover, moisture transmission of the in situ formed hydrogel was between 95 and 90 g/m(2)/h, an optimum range to avoid wound dehydration or occlusion phenomena. Release of the encapsulated GS, monitored as permeation rate using Franz cells in simulated wound fluid (SWF) was related to particle size and gelling rate. Sustained permeation profiles were obtained achieving total permeation of the drug between 3 and 6 days. However, all nano spray-dried formulations presented a burst effect, suitable to prevent infection spreading at the beginning of the therapy. Antimicrobial tests against Staphylococcus aureus and Pseudomonas aeruginosa showed stronger and prolonged antimicrobial effect of the nanoparticles compared to pure GS both shortly after administration and over time (till 12 days).

  18. New formulation of in situ gelling Metolose-based liquid suppository.

    PubMed

    Pásztor, E; Makó, A; Csóka, G; Fenyvesi, Zs; Benko, R; Prosszer, M; Marton, S; Antal, I; Klebovich, I

    2011-01-01

    An in situ gelling liquid suppository is liquid at room temperature but forms a gel at body temperature. In our work, Metolose® SM-4000 (methylcellulose) is studied that basically shows thermal gelation at 68°C (2%, w/w). The objective was to study the potency of different factors (concentration, pH, additives) to change the value of thermal gelation temperature (T (t)) for Metolose® to form an in situ gelling liquid suppository. We studied the effect of Metolose® concentration, pH, and salts (sodium chloride, potassium chloride, sodium hydrogen carbonate, and sodium monohydrogen phosphate) on T (t) by viscosimetry. To choose the appropriate compound, in vitro drug release was examined. Rectal safety test was performed on rats in vivo after 12-hour application. Increasing the Metolose® concentrations (0.5-4%, w/w), T (t) can be decreased, but it also altered the consistency of gel. pH does not affect the T (t). The water-soluble salts allowed reducing the gelation temperature to 37°C. Sodium monohydrogen phosphate in 4.5% concentration was found to be the most appropriate. The impact of examined factors on in vitro drug release of piroxicam from the in situ-formed gel was characterized according to Fickian diffusion. Metolose® and the chosen salt did not cause any morphological damage on the rectal tissues. According to our study, Metolose® has the physical and chemical potential to be used as base for liquid suppositories.

  19. Formulation and evaluation of in situ gelling systems for intranasal administration of gastrodin.

    PubMed

    Cai, Zheng; Song, Xiangrong; Sun, Feng; Yang, Zhaoxiang; Hou, Shixiang; Liu, Zhongqiu

    2011-12-01

    Gastrodin is the major bioactive constituent of the traditional Chinese drug "Tianma." It is used in the treatment of some nervous system diseases and can be transported to the brain via intranasal administration. In the current paper, the development of a novel ion-activated in situ gelling system for the nasal delivery of gastrodin is discussed. An in situ perfusion model was used to determine the absorption-rate constant of gastrodin through rat nasal mucosa. The optimal formulation was determined by measuring the critical cation concentration, anti-dilution capacity, gel expansion coefficient, water-holding capacity, and adhesive capacity. The best formulation consisted of 10% gastrodin, 0.5% deacetylated gellan gum as the gelatinizer, and 0.03% ethylparaben as the preservative. The rheological properties of gastrodin nasal in situ gels were also investigated. The viscosity and elasticity sharply increased at temperatures below 25°C. When physiological concentrations of cations were added into the preparation, the mixture gelled into a semi-solid. The results of an accelerated stability test show that gastrodin nasal in situ gels can be stable for more than 2 years. Mucociliary toxicity was evaluated using the in situ toad palate model and the rat nasal mucociliary method; both models demonstrated no measurable ciliotoxicity. Pharmacodynamic studies suggest that similar acesodyne and sedative effects were induced following intranasal administration of 50 mg/kg gastrodin nasal in situ gels or oral administration of 100 mg/kg gastrodin solution. The in situ gel preparation is a safe and effective nasal delivery system for gastrodin.

  20. Investigation of the application of gelled polymer systems for permeability modification in petroleum reservoirs: Final annual report for the period October 1985-September 1986

    SciTech Connect

    Willhite, G.P.

    1987-11-01

    The research program is directed at improvement of volumetric sweep of fluid-displacement processes using gelled polymer systems. An integrated program is underway to develop a systematic procedure for the methods which can be used for design of gelled polymer applications. The program is organized into three parts: (1) physical and chemical description of gelling systems, (2) experiemental investigation of in situ gelation in porous media, and (3) correlation and mathematical modeling of in situ gelation. This report describes progress during the first year of a three-year program. 93 refs., 59 figs., 22 tabs.

  1. A real-time PCR assay for rapid detection and quantification of Exserohilum rostratum, a causative pathogen of fungal meningitis associated with injection of contaminated methylprednisolone.

    PubMed

    Zhao, Yanan; Petraitiene, Ruta; Walsh, Thomas J; Perlin, David S

    2013-03-01

    A species-specific molecular beacon real-time PCR assay was developed for rapid diagnosis of Exserohilum rostratum infection. As low as 100 fg of E. rostratum DNA can be reliably detected in the presence of 50 ng of human DNA, with a dynamic linear quantification range from 20 ng to 200 fg.

  2. Optimization of Injectable Thermosensitive Scaffolds with Enhanced Mechanical Properties for Cell Therapy.

    PubMed

    Ceccaldi, Caroline; Assaad, Elias; Hui, Eve; Buccionyte, Medeine; Adoungotchodo, Atma; Lerouge, Sophie

    2017-06-01

    Strong injectable chitosan thermosensitive hydrogels can be created, without chemical modification, by combining sodium hydrogen carbonate with another weak base, namely, beta-glycerophosphate (BGP) or phosphate buffer (PB). Here the influence of gelling agent concentration on the mechanical properties, gelation kinetics, osmolality, swelling, and compatibility for cell encapsulation, is studied in order to find the most optimal formulations and demonstrate their potential for cell therapy and tissue engineering. The new formulations present up to a 50-fold increase of the Young's modulus after gelation compared with conventional chitosan-BGP hydrogels, while reducing the ionic strength to the level of iso-osmolality. Increasing PB concentration accelerates gelation but reduces the mechanical properties. Increasing BGP also has this effect, but to a lesser extent. Cells can be easily encapsulated by mixing the cell suspension within the hydrogel solution at room temperature, prior to rapid gelation at body temperature. After encapsulation, L929 mouse fibroblasts are homogeneously distributed within scaffolds and present a strongly increased viability and growth, when compared with conventional chitosan-BGP hydrogels. Two particularly promising formulations are evaluated with human mesenchymal stem cells. Their viability and metabolic activity are maintained over 7 d in vitro. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A Water-Based Chitosan-Maleimide Precursor for Bioconjugation: An Example of a Rapid Pathway for an In Situ Injectable Adhesive Gel.

    PubMed

    Matsumoto, Masahiro; Udomsinprasert, Wanvisa; Laengee, Prayoon; Honsawek, Sittisak; Patarakul, Kanitha; Chirachanchai, Suwabun

    2016-10-01

    Chitosan conjugated with maleimide (CS-Mal) as a potential precursor for bioconjugation and the example of the application in in situ injectable adhesive gel is proposed. The homogeneous reaction in water/dimethyl sulfoxide (DMSO) (1:1) followed by dialysis in HCl (10 × 10(-3) m) is a good condition to obtain CS-Mal. When SH-PEG-SH is applied as the crosslinker, the gel can be obtained in a few seconds without any by-products at room temperature. The gel formation and properties are controllable by simply varying the concentration and the molecular weight of CS, the Mal substitution degree, and the temperature. The gel is injectable and shows adhesive property for soft tissue. Moreover, the gel shows not only biocompatibility to SAOS2 cells but also antimicrobial activity against both gram-negative and gram-positive bacteria. CS-Mal is useful not only for bioconjugation of CS but also for development of biomaterials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Self-crosslinked oxidized alginate/gelatin hydrogel as injectable, adhesive biomimetic scaffolds for cartilage regeneration.

    PubMed

    Balakrishnan, Biji; Joshi, Nitin; Jayakrishnan, Athipettah; Banerjee, Rinti

    2014-08-01

    Biopolymeric hydrogels that mimic the properties of extracellular matrix have great potential in promoting cellular migration and proliferation for tissue regeneration. The authors reported earlier that rapidly gelling, biodegradable, injectable hydrogels can be prepared by self-crosslinking of periodate oxidized alginate and gelatin in the presence of borax, without using any toxic crosslinking agents. The present paper investigates the suitability of this hydrogel as a minimally invasive injectable, cell-attractive and adhesive scaffold for cartilage tissue engineering for the treatment of osteoarthritis. Time and frequency sweep rheology analysis confirmed gel formation within 20s. The hydrogel integrated well with the cartilage tissue, with a burst pressure of 70±3mmHg, indicating its adhesive nature. Hydrogel induced negligible inflammatory and oxidative stress responses, a prerequisite for the management and treatment of osteoarthritis. Scanning electron microscopy images of primary murine chondrocytes encapsulated within the matrix revealed attachment of cells onto the hydrogel matrix. Chondrocytes demonstrated viability, proliferation and migration within the matrix, while maintaining their phenotype, as seen by expression of collagen type II and aggrecan, and functionality, as seen by enhanced glycosoaminoglycan (GAG) deposition with time. DNA content and GAG deposition of chondrocytes within the matrix can be tuned by incorporation of bioactive signaling molecules such as dexamethasone, chondroitin sulphate, platelet derived growth factor (PDGF-BB) and combination of these three agents. The results suggest that self-crosslinked oxidized alginate/gelatin hydrogel may be a promising injectable, cell-attracting adhesive matrix for neo-cartilage formation in the management and treatment of osteoarthritis.

  5. Ibandronate Injection

    MedlinePlus

    Boniva® Injection ... Ibandronate injection is used to treat osteoporosis (a condition in which the bones become thin and weak and break ... Ibandronate injection comes as a solution (liquid) to be injected into a vein by a doctor or nurse in ...

  6. Leuprolide Injection

    MedlinePlus

    Leuprolide injection comes as a long-acting suspension (Lupron) that is injected intramuscularly (into a muscle) by a doctor or nurse in a medical ... Depot-4 month, Lupron Depot-6 Month). Leuprolide injection also comes as a long-acting suspension (Eligard) that is injected subcutaneously (just under ...

  7. On the importance of Bloom number of gelatin to the development of biodegradable in situ gelling copolymers for intracameral drug delivery.

    PubMed

    Chou, Shih-Feng; Luo, Li-Jyuan; Lai, Jui-Yang; Ma, David Hui-Kang

    2016-09-10

    To overcome the drawbacks associated with conventional antiglaucoma eye drops, this work demonstrated the feasibility of an effective alternative strategy to administer pilocarpine directly via intracameral injections of drug-containing biodegradable in situ gelling GN copolymers composed of gelatin and poly(N-isopropylacrylamide). Specifically, this study aims to understand the importance of Bloom number of gelatin, a physicochemical parameter, to the development of GN carriers for intracameral drug delivery in glaucoma therapy. Our results showed that both imino acid and triple-helix contents increased with increasing Bloom index from 75-100 to 300. The drug encapsulation efficiency in response to temperature-triggered phase transition in GN copolymers was affected by the Bloom index of gelatin. In addition, the differences in protein secondary structure significantly influenced the degradation rates of GN carriers, which were highly correlated with drug release profiles. The increase in released pilocarpine concentration led to a high intracellular calcium level in rabbit ciliary smooth muscle cell cultures, indicating a beneficial pharmacological response to a drug. Irrespective of Bloom number of gelatin, all carrier materials exhibited excellent in vitro and in vivo biocompatibility with corneal endothelium. In a glaucomatous rabbit model, intracameral injections of pilocarpine-containing GN synthesized from gelatins with various Bloom numbers had different abilities to improve ocular hypertension and induce pupillary constriction, indicating distinct antiglaucoma efficacies due to in vivo drug release. It is concluded that the effects on pharmacological treatment using GN carriers for intracameral pilocarpine administration demonstrate a strong dependence on the Bloom number of gelatin. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Possible Solution of Dark Matter, the Solution of Dark Energy and Gell-Mann as Great Theoretician

    NASA Astrophysics Data System (ADS)

    Frampton, Paul Howard

    2011-11-01

    This talk discusses the formation of primordial intermediate-mass black holes, in a double-inflationary theory, of sufficient abundance possibly to provide all of the cosmological dark matter. There follows my, hopefully convincing, explanation of the dark energy problem, based on the observation that the visible universe is well approximated by a black hole. Finally, I discuss that Gell-Mann is among the five greatest theoreticians of the twentieth century.

  9. A green analytical method for rapid determination of pectin degree of esterification using micro sequential injection lab-on-valve system.

    PubMed

    Naghshineh, Mahsa; Larsen, Jan; Georgiou, Constantinos; Olsen, Karsten

    2016-08-01

    A novel method for automated determination pectin degree of esterification (DE) using micro sequential injection lab-on-valve (μSI-LOV) system is developed. A face-centered central composite response surface methodology (RSM) was used to optimise system parameters. A calibration graph for determination of non-esterified galacturonic acid (GalA) content in pectin solutions with linear range of 0.08-0.34% (w/v) and the limit of detection (LOD) of 0.057% (w/v) under optimal condition was achieved. The difference between concentrations (w/v, %) of total GalA and non-esterified GalA was applied to estimate DE (%) of pectin samples. Results indicated a good agreement (tstat

  10. Design and evaluation of baicalin-containing in situ pH-triggered gelling system for sustained ophthalmic drug delivery.

    PubMed

    Wu, Haoyun; Liu, Zhidong; Peng, Junjie; Li, Lin; Li, Nan; Li, Jiawei; Pan, Hao

    2011-05-30

    Baicalin has been reported to have anti-inflammatory and anti-cataract effects on eye tissues, but it has a low bioavailability partly due to its poor stability of baicalin, the special anatomic structure and efficient protective mechanism of eyes. The aim of this study was to investigate the correlation between the stability of baicalin and in situ pH-triggered gelling system. Carbopol(®) 974P (0.3%, w/v) was used as the gelling agent combined with hydroxypropylmethylcellulose E4M (0.6%, w/v) which acted as a viscosity enhancing agent. In vitro and in vivo evaluations were performed using several techniques, namely confocal scanning light microscopy analysis, rheometry, Gamma scintigraphic technique and microdialysis method. The rheological behavior showed a significant enhancement in gel strength under physiological conditions, and the formulation provided sustained release of the drug over an 8-h period. In elimination studies, the radioactivity of formulation was always higher than that of the control solution. Additionally, the AUC and C(max) values were 6.1-fold and 3.6-fold higher than those of the control solution, respectively. The results demonstrated that an in situ pH-triggered gelling system have better ability to keep baicalin stable and retain drug release than marketed baicalin eye drops to enhance the ocular bioavailability. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  11. Effect of xanthan gum and guar gum on in situ gelling ophthalmic drug delivery system based on poloxamer-407.

    PubMed

    Bhowmik, Manas; Kumari, Puja; Sarkar, Gunjan; Bain, Mrinal Kanti; Bhowmick, Biplab; Mollick, Md Masud Rahaman; Mondal, Dibyendu; Maity, Dipanwita; Rana, Dipak; Bhattacharjee, Debashis; Chattopadhyay, Dipankar

    2013-11-01

    The aim of this investigation was to develop a novel in situ gelling formulation based on poloxamer-407 (PM) for the sustained release of an ophthalmic drug. In an attempt to reduce the concentration of PM without compromising the in situ gelling capability and also to increase the drug release time, xanthan gum (XG) and guar gum (GG) were added into PM to develop different formulations. At concentrations of 18% and above, the PM was able to undergo sol-gel transition below body temperature. It was found that XG and GG at a weight ratio of 3:7 were able to convert PM solution into gel below body temperature at PM concentrations below 18%. Both the in vitro and in vivo studies indicated that the PM with an XG-GG combination had a better ability to retain the drug than PM itself. The results indicated that the developed in situ gelling formulations containing PM with XG-GG may be a better alternative than a conventional eye drop.

  12. Dual controlled release, in situ gelling periodontal sol of metronidazole benzoate and serratiopeptidase: statistical optimization and mechanistic evaluation.

    PubMed

    Kumari, Neeraj; Pathak, Kamla

    2012-01-01

    In situ gelling syringeable periodontal sol capable of dual controlled delivery of metronidazole benzoate and serratiopeptidase was designed based on 2(3) factorial design with drug, poloxamer 407 and aerosil as independent variables and sol gel transition characteristics, %CDR(48h) and palatability as responses. The sols had agreeable taste, were mucoadhesive, syringeable and inverted into gels at periodontal cavity temperature. F8 with optimal drug release was identified as the best formulation. The dispersion characteristics of poloxamer significantly affected the pharmacotechnical properties of the in situ gelling systems. Extra design checkpoint generated using Design Expert software 8.02 (Stat-Ease, USA) validated the experimental design. Thus a thermoreversible, in situ gelling and syringeable periodontal sol with acceptable taste characteristics that offered controlled release of metronidazole benzoate and serratiopeptidase was developed for application into the periodontal pocket. The developed optimized sol was satisfactory in terms of taste, syringeability, palatability and incorporation of serratiopeptidase as anti-inflammatory agent, has the potential of developing a therapeutically efficacious system for treatment of periodontal inflammatory anaerobic infections.

  13. Comparison of simple, double and gelled double emulsions as hydroxytyrosol and n-3 fatty acid delivery systems.

    PubMed

    Flaiz, Linda; Freire, María; Cofrades, Susana; Mateos, Raquel; Weiss, Jochen; Jiménez-Colmenero, Francisco; Bou, Ricard

    2016-12-15

    The purpose of this study was to compare three different emulsion-based systems, namely simple emulsion, double emulsion and gelled double emulsion, for delivery of n-3 fatty acids (perilla oil at 300g/kg) and hydroxytyrosol (300mg/kg). Considering that their structural differences may affect their physical and oxidative stability, this was studied by storing them at 4°C for 22days in the dark. The results showed that the oxidative status was maintained in all systems by the addition of hydroxytyrosol. However, there was some loss of hydroxytyrosol, mainly during sample storage and during preparation of the gelled double emulsion. Moreover, the antioxidant loss was more pronounced in more compartmentalized systems, which was attributed to their increased surface area. However, the double emulsion was found to be less stable than the gelled emulsion. Overall, the encapsulation of labile compounds in more complex systems needs to be carefully studied and adapted to specific technological and/or nutritional requirements. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Effects of Partial Beef Fat Replacement with Gelled Emulsion on Functional and Quality Properties of Model System Meat Emulsions.

    PubMed

    Serdaroğlu, Meltem; Nacak, Berker; Karabıyıkoğlu, Merve; Keser, Gökçen

    2016-01-01

    The objective of this study was to investigate the effects of partial beef fat replacement (0, 30, 50, 100%) with gelled emulsion (GE) prepared with olive oil on functional and quality properties of model system meat emulsion (MSME). GE consisted of inulin and gelatin as gelling agent and characteristics of gelled and model system meat emulsions were investigated. GE showed good initial stability against centrifugation forces and thermal stability at different temperatures. GE addition decreased the pH with respect to increase in GE concentration. Addition of GE increased lightness and yellowness but reduced redness compared to control samples. The results of the study showed that partial replacement of beef fat with GE could be used for improving cooking yield without negative effects on water holding capacity and emulsion stability compared to C samples when replacement level is up to 50%. The presence of GE significantly affected textural behaviors of samples (p<0.05). In conclusion, our study showed that GE have promising impacts on developing healthier meat product formulations besides improving technological characteristics.

  15. Effects of Partial Beef Fat Replacement with Gelled Emulsion on Functional and Quality Properties of Model System Meat Emulsions

    PubMed Central

    2016-01-01

    The objective of this study was to investigate the effects of partial beef fat replacement (0, 30, 50, 100%) with gelled emulsion (GE) prepared with olive oil on functional and quality properties of model system meat emulsion (MSME). GE consisted of inulin and gelatin as gelling agent and characteristics of gelled and model system meat emulsions were investigated. GE showed good initial stability against centrifugation forces and thermal stability at different temperatures. GE addition decreased the pH with respect to increase in GE concentration. Addition of GE increased lightness and yellowness but reduced redness compared to control samples. The results of the study showed that partial replacement of beef fat with GE could be used for improving cooking yield without negative effects on water holding capacity and emulsion stability compared to C samples when replacement level is up to 50%. The presence of GE significantly affected textural behaviors of samples (p<0.05). In conclusion, our study showed that GE have promising impacts on developing healthier meat product formulations besides improving technological characteristics. PMID:28115885

  16. Rapid Quantitative Analysis of Multiple Explosive-Compound Classes on a Single Instrument via Flow-Injection Analysis Tandem Mass Spectrometry

    DTIC Science & Technology

    2017-03-20

    date,  FIA‐ MS/MS  has  been  used  for  rapid  quantitative  analysis  of  pharmaceuticals   [33], pesticides  [34], environmental con‐ taminants...that  this method’s  versatility  would  easily  allow  addition  of new compounds for analysis, and thus be  adaptable to continuously evolving...precursor ion scan of m/z 62 of the  Acrodisc™ filter extract in acetonitrile.  In  addition  as  recently  reported by  J. Oxley  [47]  an acetonitrile may

  17. Golimumab Injection

    MedlinePlus

    ... body and causes pain, swelling, and damage) including: rheumatoid arthritis (condition in which the body attacks its own ... doctor.If golimumab injection is used to treat rheumatoid arthritis, it may also be injected intravenously (into a ...

  18. Adalimumab Injection

    MedlinePlus

    ... causes pain, swelling, and damage) including the following: rheumatoid arthritis (a condition in which the body attacks its ... If you are using adalimumab injection to treat rheumatoid arthritis, your doctor may tell you to inject the ...

  19. Ipilimumab Injection

    MedlinePlus

    ... are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while receiving ipilimumab injection, call your doctor. Ipilimumab injection may cause your baby to be born too early or to die before birth.

  20. Teniposide Injection

    MedlinePlus

    ... in men. You should not become pregnant or breast-feed while you are receiving teniposide injection. If you or your partner become pregnant while receiving teniposide injection, call your doctor. Teniposide may harm the fetus.

  1. Dexrazoxane Injection

    MedlinePlus

    ... Dexrazoxane injection (Zinecard) is used to prevent or decrease heart damage caused by doxorubicin in women who ... with doxorubicin. Dexrazoxane injection (Totect) is used to decrease damage to the skin and tissues that may ...

  2. Colistimethate Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria. Colistimethate injection is in a class of medications called antibiotics. It works by killing bacteria.Antibiotics such as colistimethate injection will not work ...

  3. Chloramphenicol Injection

    MedlinePlus

    ... treat certain types of serious infections caused by bacteria when other antibiotics cannot be used. Chloramphenicol injection ... antibiotics. It works by stopping the growth of bacteria..Antibiotics such as chloramphenicol injection will not work ...

  4. Natalizumab Injection

    MedlinePlus

    ... your condition. Keep all appointments to receive natalizumab injection even if you feel well. ... tests to check your body's response to natalizumab injection.It is important ... you are taking, as well as any products such as vitamins, minerals, or ...

  5. Methylnaltrexone Injection

    MedlinePlus

    ... taking opioid medications, you should stop using methylnaltrexone injection as well.You should stop taking other laxative medications when you start using methylnaltrexone injection. However, be sure to let your doctor know ...

  6. Triptorelin Injection

    MedlinePlus

    ... used to treat the symptoms associated with advanced prostate cancer. Triptorelin injection (Triptodur) is used to treat central ... a medical office or clinic. When used for prostate cancer, an injection of 3.75 mg of triptorelin ( ...

  7. Degarelix Injection

    MedlinePlus

    Degarelix injection is used to treat advanced prostate cancer (cancer that begins in the prostate [a male reproductive gland]). Degarelix injection is in a class of medications called gonadotropin-releasing hormone (GnRH) ...

  8. Medroxyprogesterone Injection

    MedlinePlus

    ... Medroxyprogesterone injection is a very effective method of birth control but does not prevent the spread of human ... you have been using a different method of birth control and are switching to medroxyprogesterone injection, your doctor ...

  9. Dolasetron Injection

    MedlinePlus

    ... treat nausea and vomiting that may occur after surgery. Dolasetron injection should not be used to prevent ... a single injection just before the end of surgery or as soon as nausea or vomiting occurs. ...

  10. Levoleucovorin Injection

    MedlinePlus

    Levoleucovorin injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall) when methotrexate is used to to treat certain types of cancer. Levoleucovorin injection is also used to treat people ...

  11. Etelcalcetide Injection

    MedlinePlus

    Etelcalcetide injection is used to treat secondary hyperparathyroidism (condition in which the body produces too much parathyroid ... blood when the kidneys are not working properly.) Etelcalcetide injection is in a class of medications called ...

  12. Dupilumab Injection

    MedlinePlus

    ... injection is used to treat the symptoms of eczema (atopic dermatitis; a skin disease that causes the ... use other medications for their condition or whose eczema has not responded to other medications. Dupilumab injection ...

  13. Methylprednisolone Injection

    MedlinePlus

    ... allergic reactions. Methylprednisolone injection is used in the management of multiple sclerosis (a disease in which the ... laboratory test, tell your doctor and the laboratory personnel that you are using methylprednisolone injection.If you ...

  14. Clindamycin Injection

    MedlinePlus

    ... your treatment with clindamycin injection or during the first several months after your treatment is finished: watery or bloody stools, diarrhea, stomach cramps, or fever.Talk to your doctor about the risks of receiving clindamycin injection.

  15. Obinutuzumab Injection

    MedlinePlus

    Obinutuzumab injection is used with chlorambucil (Leukeran) to treat chronic lymphocytic leukemia (CLL; a type of cancer of the white blood cells). Obinutuzumab injection is in a class of medications called ...

  16. Ferumoxytol Injection

    MedlinePlus

    Ferumoxytol injection is used to treat iron-deficiency anemia (a lower than normal number of red blood ... and may cause the kidneys to stop working). Ferumoxytol injection is in a class of medications called ...

  17. Pralatrexate Injection

    MedlinePlus

    Pralatrexate injection is used to treat peripheral T-cell lymphoma (PTCL; a form of cancer that begins in a ... come back after treatment with other medications. Pralatrexate injection has not been shown to help people who ...

  18. Cyanocobalamin Injection

    MedlinePlus

    Cyanocobalamin injection is used to treat and prevent a lack of vitamin B12 that may be caused by any ... organs) and permanent damage to the nerves. Cyanocobalamin injection also may be given as a test to ...

  19. Paclitaxel Injection

    MedlinePlus

    Paclitaxel injection manufactured with human albumin is used to treat breast cancer that has not improved or that has come back after treatment with other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to ...

  20. Peramivir Injection

    MedlinePlus

    Peramivir injection is used to treat some types of influenza infection ('flu') in people who have had symptoms of ... flu for no longer than 2 days. Peramivir injection is in a class of medications called neuraminidase ...

  1. Cefotetan Injection

    MedlinePlus

    Cefotetan injection is used to treat infections of the lungs, skin, bones, joints, stomach area, blood, female reproductive organs, and urinary tract. Cefotetan injection is also used before surgery to prevent infections. ...

  2. Mipomersen Injection

    MedlinePlus

    Mipomersen injection is used to decrease levels of cholesterol and other fatty substances in the blood in people who ... that removes LDL from the blood), but mipomersen injection should not be used along with this treatment. ...

  3. Romiplostim Injection

    MedlinePlus

    Romiplostim injection is used to increase the number of platelets (cells that help the blood to clot) in order ... low number of platelets in the blood). Romiplostim injection should only be used in people who cannot ...

  4. Hydrocortisone Injection

    MedlinePlus

    Hydrocortisone injection is used to treat symptoms of low corticosteroid levels (lack of certain substances that are usually produced ... also used to treat severe allergic reactions. Hydrocortisone injection is used in the management of multiple sclerosis ( ...

  5. Palivizumab Injection

    MedlinePlus

    Palivizumab injection is used to help prevent respiratory syncytial virus (RSV; common virus that can cause serious lung infections) ... or have certain heart or lung diseases. Palivizumab injection is not used to treat the symptoms of ...

  6. Naltrexone Injection

    MedlinePlus

    Naltrexone injection is used along with counseling and social support to help people who have stopped drinking large amounts of alcohol to avoid drinking again. Naltrexone injection is also used along with counseling and social ...

  7. Tesamorelin Injection

    MedlinePlus

    Tesamorelin injection is used to decrease the amount of extra fat in the stomach area in adults with human ... fat in certain areas of the body). Tesamorelin injection is not used to help with weight loss. ...

  8. Tigecycline Injection

    MedlinePlus

    Tigecycline injection used to treat certain serious infections including community acquired pneumonia (a lung infection that developed in a ... area between the chest and the waist). Tigecycline injection should not be used to treat pneumonia that ...

  9. Eculizumab Injection

    MedlinePlus

    Eculizumab injection is used to treat paroxysmal nocturnal hemoglobinuria (PNH: a type of anemia in which too many red ... oxygen to all parts of the body). Eculizumab injection is also used to treat atypical hemolytic uremic ...

  10. Pembrolizumab Injection

    MedlinePlus

    Pembrolizumab injection is used to treat melanoma (a type of skin cancer) that cannot be treated with surgery or ... spread to other parts of the body. Pembrolizumab injection is also used to treat a certain type ...

  11. Oxacillin Injection

    MedlinePlus

    ... is used to treat infections caused by certain bacteria. Oxacillin injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as oxacillin injection will not work ...

  12. Cefoxitin Injection

    MedlinePlus

    ... injection is used to treat infections caused by bacteria including pneumonia and other lower respiratory tract (lung) ... medications called cephamycin antibiotics. It works by killing bacteria.Antibiotics such as cefoxitin injection will not work ...

  13. Nafcillin Injection

    MedlinePlus

    ... to treat infections caused by certain types of bacteria. Nafcillin injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as nafcillin injection will not work ...

  14. Doripenem Injection

    MedlinePlus

    ... tract, kidney, and abdomen that are caused by bacteria. Doripenem injection is not approved by the Food ... medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as doripenem injection will not work ...

  15. Performance of commercial aluminium alloys as anodes in gelled electrolyte aluminium-air batteries

    NASA Astrophysics Data System (ADS)

    Pino, M.; Chacón, J.; Fatás, E.; Ocón, P.

    2015-12-01

    The evaluation of commercial aluminium alloys, namely, Al2024, Al7475 and Al1085, for Al-air batteries is performed. Pure Al cladded Al2024 and Al7475 are also evaluated. Current rates from 0.8 mA cm-2 to 8.6 mA cm-2 are measured in a gel Al-air cell composed of the commercial alloy sample, a commercial air-cathode and an easily synthesizable gelled alkaline electrolyte. The influence of the alloying elements and the addition to the electrolyte of ZnO and ZnCl2, as corrosion inhibitors is studied and analysed via EDX/SEM. Specific capacities of up to 426 mAh/g are obtained with notably flat potential discharges of 1.3-1.4 V. The competition between self-corrosion and oxidation reactions is also discussed, as well as the influence of the current applied on that process. Al7475 is determined to have the best behaviour as anode in Al-air primary batteries, and cladding process is found to be an extra protection against corrosion at low current discharges. Conversely, Al1085 provided worse results because of an unfavourable metallic composition.

  16. Extraction and Characterization of Highly Gelling Low Methoxy Pectin from Cashew Apple Pomace

    PubMed Central

    Yapo, Beda M.; Koffi, Kouassi L.

    2013-01-01

    Investigation on the pectic substances of cashew (Anacardium occidentale L.) apple under different acid-extraction conditions (pH 1.0, 1.5, and 2.0) showed that more than 10%–25% of A. occidentale pectins (AOP) could be extracted, depending on the extractant strength. The extracted AOP contained high amounts of galacturonic acid (GalA: 69.9%–84.5%) with some neutral sugars of which rhamnose (Rha: 1.3%–2.5%), arabinose (Ara: 2.6%–5.4%), and galactose (Gal: 4.7%–8.6%) were the main constituents. The degree of methoxylation (DM) was in the range of 28%–46% and was only slightly affected by the extractant strength, thereby indicating isolation of naturally low methoxy pectins (LMP). In terms of gelling capability, AOP yielded firmer Ca2+-mediated LMP gels than commercial citrus LMP with comparable DM. Cashew apple pomace, therefore, appears to be a potentially viable source for possible production of “non-chemically or enzymatically-tailored” LMP. PMID:28234301

  17. Assessing gelling properties of chia (Salvia hispanica L.) flour through rheological characterization.

    PubMed

    Ramos, Susana; Fradinho, Patrícia; Mata, Paulina; Raymundo, Anabela

    2017-04-01

    Chia (Salvia hispanica L.) seeds are considered a promising ingredient for the development of functional products owing to their high nutritional value: 343 g kg(-1) lipids, 251 g kg(-1) protein and 226 g kg(-1) fibre. Considering chia's technological capacities, mainly the ability to swell when absorbing water and gel-forming properties, its addition to a food matrix can affect texture and rheological behaviour, acting as a texturing and stabilizing agent. The aim of the present work was to assess the gelling properties of chia flour through the rheological characterization of 100, 130 and 150 g kg(-1) chia flour gels. According to the mechanical spectra, all gels presented weak gel-like structures, as G' was always less than a decade higher than G″, but higher chia flour concentrations showed a considerable increase in viscoelastic moduli. The gels had relatively low maturation times, almost instantaneous for lower concentrations, but the cooling rate affected the dynamics of formation of the gel structure. Based on texture and rheological properties, gels with 130 g kg(-1) of chia flour processed at 90 °C for 30 min showed the most suitable characteristics for use in the development of new food applications. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Linseed oil gelled emulsion: A successful fat replacer in dry fermented sausages.

    PubMed

    Alejandre, Marta; Poyato, Candelaria; Ansorena, Diana; Astiasarán, Iciar

    2016-11-01

    Different levels of animal fat replacement by a high omega-3 content carrageenan gelled emulsion in dry fermented sausages were studied in order to improve their fatty acid composition. Percentages of fat replacement were 26.3% (SUB1), 32.8% (SUB2) and 39.5% (SUB3). α-linolenic acid (ALA) content increased up to 1.81, 2.19 and 2.39g/100g (SUB1, SUB2, and SUB3 products) as compared to the Control (0.35g/100g), implying an increment in polyunsaturated fatty acids (PUFA) supply (up to 10.3%) and reductions in omega-6/ omega-3 ratio (75, 82 and 84%, respectively). Peroxides and TBARs values were not affected (P>0.05) by the fat modification and a slight low formation of volatile aldehydes derived from lipid oxidation was detected. Fat replacement did not cause relevant modifications on the instrumental color properties and no sensory differences (P>0.05) were found between Control and SUB2 products (32.8%) for taste and juiciness, pointing out the viability of this formulation for human consumption.

  19. Improving reservoir conformance using gelled polymer systems. Annual report, September 15, 1993--September 24, 1994

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1995-07-01

    The objectives of the research program are to (1) identify and develop polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focuses on three types of aqueous gel systems - a polysaccharide (KUSP1) that gels as a function of pH, a polyacrylamide-chromium(III) system and a polyacrylamide-aluminum citrate system. This report describes work conducted during the second year of a three-year program. Progress was made in the utilization of KUSP1 as a gelling agent. It was shown that gels can be formed in situ in porous media using CO{sub 2} or ester hydrolysis to lower pH. An ester was identified that could be used in field-scale operations. It was determined that KUSP1 will form strong gels when ortho boric acid is added to the system. It was also determined, in cooperation with Abbott Laboratories, that KUSP1 can be produced on a commercial scale. Rheological studies showed that shear rate significantly affects gelation time and gel strength. The effect of rock-fluid interactions at alkaline conditions was examined experimentally and through mathematical modeling. A model was developed that treats non-equilibrium conditions and this is an improvement over previously published models.

  20. Effect of protein structure on water and fat distribution during meat gelling.

    PubMed

    Yang, Huijuan; Zhang, Wangang; Li, Teng; Zheng, Haibo; Khan, Muhammad Ammar; Xu, Xinglian; Sun, Jingxin; Zhou, Guanghong

    2016-08-01

    Emulsion-type sausages were produced, at 80°C for either 0, 10, 20 or 30min, using homogeneous Taihu pork batters. Low-field nuclear magnetic resonance (LF-NMR), with or without deuterium oxide (D2O) substitution, evaluated the proton mobility states related to both water and fat molecules, or fat molecules only, respectively, in the sausage samples, during heat-induced gelation. The decreasing trend in the area proportion of main peak T21, reflected a tighter gel structure in emulsion-type sausages. Raman spectra (400-3600cm(-1)) revealed decreased α-helix, but increased β-sheet, β-turns and random coil contents, during the gelling process. Moreover, principal component analysis (PCA) showed significant correlations between secondary protein structures with distribution of water and fat in the gel matrix. Furthermore, this study established the relationship of water and fat protons mobility with changes in secondary protein structures, and described the critical time of gel formation in emulsion-type pork sausages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Improving reservoir conformance using gelled polymer systems. Annual report, September 25, 1992--September 24, 1993

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1994-08-01

    The general objectives of the research program are to (1) identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focuses on three types of gel systems-an aqueous polysaccharide (KUSPI) that gels as a function of pH, polyacrylamide or xanthan crosslinked by CR(III) and a polyacrylamide-aluminum citrate system. Work to date has focused primarily on development of a database, selection of systems, and work to characterize the gel/polymer physical properties and kinetics. The use of ester hydrolysis to control the rate of pH change of a gel system has been investigated and this approach to gel-time control shows promise. Extensive kinetic data were taken on the uptake of CR(III) oligomers by polyacrylamide. A model was developed which describes very well the monomer uptake rates. The model described the dimer uptake data less well and the trimer uptake data poorly. Studies of the flow and gelation in rock materials have been initiated. A mathematical model of rock-fluid interaction during flow of high pH solutions has been developed.

  2. Enzymatically degradable temperature-sensitive polypeptide as a new in-situ gelling biomaterial.

    PubMed

    Jeong, Yuri; Joo, Min Kyung; Bahk, Kyung Hyun; Choi, Yun Young; Kim, Ho-Tae; Kim, Won-Ki; Lee, Hwa Jeong; Sohn, Youn Soo; Jeong, Byeongmoon

    2009-07-01

    We are reporting a poly (ethylene glycol)-block-poly(alanine-co-phenyl alanine) (PEG-PAF) aqueous solution that undergoes sol-to-gel transition as the temperature increases. The sol-to-gel transition was observed at as low a concentration as 3.0-7.0 wt.%. Micellar aggregation accompanying small conformational changes of the peptide from random coils to beta-sheets is suggested as the sol-to-gel transition mechanism of the PEG-PAF aqueous solution. The PEG-PAF is stable in phosphate buffered saline, however, it degraded in the subcutaneous layer of rats. In vitro study showed that proteolytic enzymes such as cathepsin B, cathepsin C, and elastase that are present in the subcutaneous layer of the mammalian tissue might be responsible for the degradation of the polymer in rats. As a feasibility study of this material, a single shot of an aqueous insulin formulation (13.8 mg insulin/kg) showed a hypoglycemic effect over 18 days in rats. The current functional polypeptide may be very promising as an in-situ gelling system for tissue engineering, cell/stem cell therapy, and drug delivery.

  3. Cidofovir Injection

    MedlinePlus

    ... in babies whose mothers received cidofovir injection during pregnancy. You should not use cidofovir injection while you are pregnant or plan to become pregnant unless your doctor decides that this is the best treatment for your condition.Cidofovir injection has caused tumors ...

  4. Albiglutide Injection

    MedlinePlus

    ... blood) when other medications did not control levels well enough. Albiglutide injection is not used to treat type 1 diabetes ( ... does not cure it. Continue to use albiglutide injection even if you feel well. Do not stop using albiglutide injection without talking ...

  5. Nalbuphine Injection

    MedlinePlus

    ... Your doctor may adjust your dose of nalbuphine injection during your treatment, depending on how well your pain is controlled and on the side effects that you experience. Talk to your doctor about how you are feeling ... nalbuphine injection.You may receive nalbuphine injection in a hospital, ...

  6. Liraglutide Injection

    MedlinePlus

    ... blood) when other medications did not control levels well enough. Liraglutide injection (Victoza) is not used to treat type 1 ... does not cure it. Continue to use liraglutide injection even if you feel well. Do not stop using liraglutide injection without talking ...

  7. Meperidine Injection

    MedlinePlus

    ... Your doctor may adjust your dose of meperidine injection during your treatment, depending on how well your pain is controlled and on the side effects that you experience. Talk to your doctor about how you are feeling ... meperidine injection.If you have used meperidine injection for longer ...

  8. Dulaglutide Injection

    MedlinePlus

    ... blood) when other medications did not control levels well enough. Dulaglutide injection is not used to treat type 1 diabetes ( ... does not cure it. Continue to use dulaglutide injection even if you feel well. Do not stop using dulaglutide injection without talking ...

  9. Morphine Injection

    MedlinePlus

    ... Your doctor may adjust your dose of morphine injection during your treatment, depending on how well your pain is controlled and on the side effects that you experience. Talk to your doctor about how you are feeling ... with morphine injection.If you have used morphine injection for longer ...

  10. Busulfan Injection

    MedlinePlus

    Busulfex® Injection ... Busulfan injection is used to treat a certain type of chronic myelogenous leukemia (CML; a type of cancer of ... of 16 doses) before bone marrow transplant.Busulfan injection may cause seizures during therapy with the medication. ...

  11. Type 1 diabetes control and pregnancy outcomes in women treated with continuous subcutaneous insulin infusion (CSII) or with insulin glargine and multiple daily injections of rapid-acting insulin analogues (glargine-MDI).

    PubMed

    Bruttomesso, D; Bonomo, M; Costa, S; Dal Pos, M; Di Cianni, G; Pellicano, F; Vitacolonna, E; Dodesini, A R; Tonutti, L; Lapolla, A; Di Benedetto, A; Torlone, E

    2011-11-01

    The best way to treat pregnant patients who have type 1 diabetes is still unclear. For this reason, the present study compared metabolic control and maternal-fetal outcomes in patients treated with continuous subcutaneous infusions of rapid-acting insulin analogues (CSII) or with insulin glargine and multiple daily injections of rapid-acting insulin analogues (glargine-MDI). This retrospective multicentre study involved 144 women with type 1 diabetes, 100 of whom were using CSII and 44 glargine-MDI. Outcomes analyzed were metabolic control, diabetes complications, pregnancy outcome, perinatal morbidity and mortality, and fetal malformations. The two groups were comparable for age, prepregnancy BMI, primiparous rate and diabetes complications, although patients using CSII had longer duration of diabetes (P=0.03) and higher White classifications (P=0.04). In both groups, metabolic control improved during pregnancy, but good control was reached earlier among patients using CSII. At parturition, patients using CSII had lower HbA(1c) (6.2±0.7% vs 6.5±0.8%; P=0.02) and required less insulin (P<0.01). Weight gain was similar in both groups, and maternal-fetal outcomes did not differ. In pregnant patients with type 1 diabetes, MDI and CSII are equivalent in terms of metabolic control and fetal-maternal outcomes, although patients using CSII achieved good control earlier and with less insulin. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  12. A simple, rapid and sensitive ultraviolet-visible spectrophotometric technique for the determination of ultra-trace copper based on injection-ultrasound-assisted dispersive liquid-liquid microextraction.

    PubMed

    Liao, Xiaoxiang; Liang, Bing; Li, Zhenzhen; Li, Yanfang

    2011-11-07

    In this work, a simple, rapid and sensitive UV-visible spectrophotometric technique for the determination of copper based on injection-ultrasound-assisted dispersive liquid-liquid microextraction (IUSA-DLLME) was developed, using sodium diethyl-dithiocarbamate (Na-DDTC) as a complexing agent. The fabrication of a home-made microporous plastic tip was first reported, and by using it, contamination from a metallic tip was avoided; moreover cloudy solutions were easily obtained. Several parameters were investigated including the extraction solvent type and volume, pH of the reaction solution, concentration of DDTC, salt addition, reaction time and temperature, and sonication and centrifugation time. The results showed that carbon tetrachloride was a better extraction solvent. Under the optimal conditions, the calibration curve was linear in the range of 0.5-50 ng mL(-1) of copper with a R(2) of 0.9996. The relative standard deviation (RSD) for the determination of 0.5 ng mL(-1) copper was ±3.3% (n = 7), and the detection limit (3*Sb*c/m) was 0.05 ng mL(-1) in the original solution. An enrichment factor of 222 was obtained. The developed method was validated by analysis of a certified reference solution and applied successfully to the determination of copper in tap water, bottled pure water and river water. The advantages of the IUSA-DLLME method are simplicity of operation, rapidity, low cost, low LOD and high enrichment factor.

  13. New approach for vertical bone regeneration using in situ gelling and sustained BMP-2 releasing poly(phosphazene) hydrogel system on peri-implant site with critical defect in a canine model.

    PubMed

    Seo, Bo-Bae; Chang, Hae-Im; Choi, Hyuck; Koh, Jeong-Tae; Yun, Kwi-Dug; Lee, Jae-Yeol; Song, Soo-Chang

    2017-03-23

    An injectable hydrogel system with sustained bone morphogenetic protein 2 (BMP-2) release ability was developed for vertical bone regeneration at peri-implant sites and enhanced osseointegration of dental implants. In three young male beagle dogs, a pair of defects was created on both sides of the mandibular bone. Next, two implants were transplanted into each defect. In situ gelling polymer solutions with or without BMP-2 were applied to cover the implants and mandibular defects. The effects of the in situ gelling and sustained BMP-2 releasing (IGSR) hydrogel system on peri-implant bone regeneration were evaluated by radiologic examination, micro-computed tomography, and histomorphometric analysis. Twelve weeks after the treatment, significant bone generation at the peri-implant site occurred following BMP-2/IGSR hydrogel treatment. Bone volume and mineral density were increased by 1.7- and 1.3-fold, respectively (p < 0.01 and 0.05 vs. control, respectively) for the BMP-2/IGSR hydrogel system. And, 0.57-0.31 mm vertical bone generation was observed at the peri-implant site for the BMP-2/IGSR hydrogel system, while rare vertical bone generation occurred in the control group. The BMP-2/IGSR hydrogel system significantly increased bone to implant contact % between induced bone and existing bone (p < 0.05 and 0.01 vs. control). These vertical bone regeneration and higher osseointegration levels demonstrated the effectiveness of the BMP-2/IGSR hydrogel system. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.

  14. Rapid non-invasive quality control of semi-finished products for the food industry by direct injection mass spectrometry headspace analysis: the case of milk powder, whey powder and anhydrous milk fat.

    PubMed

    Makhoul, Salim; Yener, Sine; Khomenko, Iuliia; Capozzi, Vittorio; Cappellin, Luca; Aprea, Eugenio; Scampicchio, Matteo; Gasperi, Flavia; Biasioli, Franco

    2016-09-01

    In this study, we demonstrated the suitability of direct injection mass spectrometry headspace analysis for rapid non-invasive quality control of semi-finished dairy ingredients, such as skim milk powder (SMP), whole milk powder (WMP), whey powder (WP) and anhydrous milk fat (AMF), which are widely used as ingredients in the food industry. In this work, for the first time, we applied proton transfer reaction-mass spectrometry (PTR-MS) with a time-of-flight (ToF) analyzer for the rapid and non-invasive analysis of volatile compounds in different samples of SMP, WMP, WP and AMF. We selected different dairy ingredients in various concrete situations (e.g. same producer and different expiration times, different producers and same days of storage, different producers) based on their sensory evaluation. PTR-ToF-MS allowed the separation and characterization of different samples based on the volatile organic compound (VOC) profiles. Statistically significant differences in VOC content were generally coherent with differences in sensory evaluation, particularly for SMP, WMP and WP. The good separation of SMP samples from WMP samples suggested the possible application of PTR-ToF-MS to detect possible cases of adulteration of dairy ingredients for the food industry. Our findings demonstrate the efficient and rapid differentiation of dairy ingredients on the basis of the released VOCs via PTR-ToF-MS analysis and suggest this method as a versatile tool (1) for the facilitation/optimization of the selection of dairy ingredients in the food industry and (2) and for the prompt innovation in the production of dairy ingredients. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Internally self-assembled thermoreversible gelling emulsions: ISAsomes in methylcellulose, kappa-carrageenan, and mixed hydrogels.

    PubMed

    Tomsic, Matija; Guillot, Samuel; Sagalowicz, Laurent; Leser, Martin E; Glatter, Otto

    2009-08-18

    Self-assembled thermo-gelling emulsions were developed by blending internally self-assembled particles (ISAsomes) with thermoreversible polysaccharide hydrogels of methylcellulose (MC), kappa-carrageenan (KC), and their 1:1 mixture. In this way, the hierarchical structure of ISAsome samples was successfully promoted. The gelified polymer network corresponds to the highest level of the hierarchical structure and as such represents the capturing matrix for the medium structural level, i.e., dispersed emulsion particles, which are further internally structured as the lowest level of structure. Utilizing small-angle X-ray scattering, differential scanning calorimetry, dynamic light scattering, and oscillatory rheological experiments in the temperature regime from 20 to 70 degrees C, we were able to show that the ISAsomes stay practically intact during such embedment into a hydrogel matrix retaining its internal self-assembled structure and its functionality. The characteristic sol-gel and gel-sol transition temperatures of the ISAsome-loaded hydrogel samples showed a slight shift in comparison to the unloaded hydrogel samples. Furthermore, we found that MC is actually able to stabilize the ISAsomes at higher temperatures (tests were conducted up to 90 degrees C). Gels made from MC and KC show quite different features in terms of rheology and differential scanning calorimetry. However, the most interesting results were obtained for the ISAsome-loaded MC-KC (1:1) gelifying system, which behaves as a low- and high-temperature gel with a narrow intermediate temperature window where it is a sol. This specific thermal behavior allows for easy temperature tuning of the system's aggregate state as well as the internal self-assembled structure. As such, this system is suggested to be further tested as the potential media for a temperature-controlled burst/sustained release media of various hydrophilic, hydrophobic, or amphiphilic guest functional molecules.

  16. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent.

    PubMed

    Patel, Ashok R; Babaahmadi, Mehrnoosh; Lesaffer, Ans; Dewettinck, Koen

    2015-05-20

    The aim of this study was to use a detailed rheological characterization to gain new insights into the gelation behavior of natural waxes. To make a comprehensive case, six natural waxes (differing in the relative proportion of chemical components: hydrocarbons, fatty alcohols, fatty acids, and wax esters) were selected as organogelators to gel high-oleic sunflower oil. Flow and dynamic rheological properties of organogels prepared at critical gelling concentrations (Cg) of waxes were studied and compared using drag (stress ramp and steady flow) and oscillatory shear (stress and frequency sweeps) tests. Although, none of the organogels satisfied the rheological definition of a "strong gel" (G″/G' (ω) ≤ 0.1), on comparing the samples, the strongest gel (highest critical stress and dynamic, apparent, and static yield stresses) was obtained not with wax containing the highest proportion of wax esters alone (sunflower wax, SFW) but with wax containing wax esters along with a higher proportion of fatty alcohols (carnauba wax, CRW) although at a comparatively higher Cg (4%wt for latter compared to 0.5%wt for former). As expected, gel formation by waxes containing a high proportion of lower melting fatty acids (berry, BW, and fruit wax, FW) required a comparatively higher Cg (6 and 7%wt, respectively), and in addition, these gels showed the lowest values for plateau elastic modulus (G'LVR) and a prominent crossover point at higher frequency. The gelation temperatures (TG'=G″) for all the studied gels were lower than room temperature, except for SFW and CRW. The yielding-type behavior of gels was evident, with most gels showing strong shear sensitivity and a weak thixotropic recovery. The rheological behavior was combined with the results of thermal analysis and microstructure studies (optical, polarized, and cryo-scanning electron microscopy) to explain the gelation properties of these waxes.

  17. Lipid/alginate nanoparticle-loaded in situ gelling system tailored for dexamethasone nasal delivery.

    PubMed

    Dukovski, Bisera Jurišić; Plantić, Ivana; Čunčić, Ivan; Krtalić, Iva; Juretić, Marina; Pepić, Ivan; Lovrić, Jasmina; Hafner, Anita

    2017-05-31

    In this study, we suggest the development of nanoparticle loaded in situ gelling system suitable for corticosteroid nasal delivery. We propose lipid/alginate nanoparticles (size 252.3±2.4nm, polydispersity index 0.241, zeta-potential -31.7±1.0mV, dexamethasone (Dex) content 255±7μgml(-1)) dispersed in pectin solution (5mgml(-1)) that undergoes a sol-gel phase transition triggered by Ca(2+) present in nasal mucosa. The viscoelasticity of gel obtained by mixing nanoparticle suspension in pectin continuous phase with simulated nasal fluid (1:1V/V) is characterised by a log-linear shear thinning viscosity behaviour. Observed viscosity corresponds to the range of viscosities of nasal mucus at physiological as well as under disease conditions. Nanoparticle-loaded gel was biocompatible with the selected epithelial cell model and, in comparison to dexamethasone solution, provided reduction in Dex release (t50% 2.1h and 0.6h, respectively) and moderated transepithelial permeation in vitro (Papp 7.88±0.15 and 9.73±0.57×10(-6)cms(-1), respectively). In conclusion, this study showed the potential of the proposed system to provide local therapeutic effect upon administration of a lower corticosteroid dose and minimize the possibility for adverse effects as it can be easily sprayed as solution and delivered beyond nasal valve, ensure prolonged contact time with nasal mucosa upon gelation, and moderate corticosteroid release and permeation. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. In situ gelling properties of chitosan-thioglycolic acid conjugate in the presence of oxidizing agents.

    PubMed

    Sakloetsakun, Duangkamon; Hombach, Juliane M R; Bernkop-Schnürch, Andreas

    2009-10-01

    The rheological behaviour of chitosan-thioglycolic acid conjugate (chitosan-TGA) in the presence of four oxidizing agents was investigated. Chitosan-TGA was synthesized via amide bond formation between the primary amino group of chitosan and the carboxylic acid group of thioglycolic acid. The sol-gel phase transition of the polymer was determined by rheological measurements. Moreover, cytotoxicity of the gel in combination with each oxidizing agent was evaluated utilizing LDH and MTT assay. The modified chitosan displayed 1053+/-44 micromol/g thiol groups. Results of rheological studies showed that 1% (m/v) chitosan-TGA without any oxidizing agents became gel within 40 min. In contrast, when the oxidizing agents hydrogen peroxide, sodium periodate, ammonium persulfate and sodium hypochlorite were added, respectively, gelation took place within a few minutes. Within 20 min, hydrogen peroxide having been added in a final concentration of 25.2 nmol/L increased dynamic viscosity of 1% (m/v) chitosan-TGA up to 16,500-fold. This can be explained by the formation of inter- and/or intramolecular disulfide bonds which were indirectly verified via the decrease in thiol groups. Additionally, evidence of an increase in cross-linking of thiolated chitosan as a function of time was provided by frequency sweep measurements. Furthermore, viability of Caco-2 cells having been incubated with chitosan-TGA/oxidizing agent systems assessed by MTT assay was 70-85% and the percentage of LDH release was only in case of the chitosan-TGA/ammonium persulfate system significantly (p<0.05) raising compared to the negative control. According to these results, chitosan-TGA/oxidizing agent combinations might be a promising novel in situ gelling system for various pharmaceutical applications such as a controlled drug release carrier or for tissue engineering.

  19. The key to success: Gelled-electrolyte and optimized separators for stationary lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Toniazzo, Valérie

    The lead acid technology is nowadays considered one of the best suited for stationary applications. Both gel and AGM batteries are complementary technologies and can provide reliability and efficiency due to the constant optimization of the battery design and components. However, gelled-electrolyte batteries remain the preferred technology due to a better manufacturing background and show better performance mainly at low and moderate discharge rates. Especially, using the gel technology allows to get rid of the numerous problems encountered in most AGM batteries: drainage, stratification, short circuits due to dendrites, and mostly premature capacity loss due to the release of internal cell compression. These limitations are the result of the evident lack of an optimal separation system. In gel batteries, on the contrary, highly efficient polymeric separators are nowadays available. Especially, microporous separators based on PVC and silica have shown the best efficiency for nearly 30 years all over the world, and especially in Europe, where the gel technology was born. The improved performance of these separators is explained by the unique extrusion process, which leads to excellent wettability, and optimized physical properties. Because they are the key for the battery success, continuous research and development on separators have led to improved properties, which render the separator even better adapted to the more recent gel technology: the pore size distribution has been optimized to allow good oxygen transfer while avoiding dendrite growth, the pore volume has been increased, the electrical resistance and acid displacement reduced to such an extent that the electrical output of batteries has been raised both in terms of higher capacity and longer cycle life.

  20. Nasal drug delivery: Design of a novel mucoadhesive and in situ gelling polymer.

    PubMed

    Menzel, Claudia; Jelkmann, Max; Laffleur, Flavia; Bernkop-Schnürch, Andreas

    2017-01-30

    The aim of the present study was to establish a novel polymeric excipient for liquid nasal dosage forms exhibiting viscosity increasing properties, improved mucoadhesion and stability towards oxidation in solution. In order to achieve this goal, 2-mercaptonicotinic acid was first coupled to l-cysteine by disulfide exchange reaction and after purification directly attached to the polymeric backbone of xanthan gum by carbodiimide mediated amide bond formation. The resulting conjugate was characterized with respect to the amount of coupled ligand, the in situ gelling behavior, mucoadhesive properties and stability towards oxidation. Furthermore, the influence of preactivated polymers on ciliary beat frequency (CBF) of porcine nasal epithelial cells was investigated. Results showed, that 252.52±20.54μmol of the ligand was attached per gram polymer. No free thiol groups could be detected on the polymeric backbone indicating entire preactivation. Rheological investigations of polymer mucus mixtures revealed a 1.7-fold and 2.5-fold enhanced mucoadhesion of entirely preactivated xanthan (Xan-Cys-MNA) compared to thiolated xanthan (Xan-Cys) and unmodified xanthan (Xan). Tensile force evaluation reported a 2.87 and 5.11-fold higher total work of adhesion (TWA) as well as a 1.63 and 2.41-fold higher maximum detachement force of Xan-Cys-MNA compared to Xan-Cys and Xan. In the presence of H2O2 as an oxidizing agent Xan-Cys-MNA showed unlike Xan-Cys no increase in viscosity, indicating high stability towards oxidation. Addition of CaCl2 to Xan-Cys-MNA solutions caused a decrease in viscosity at nevertheless higher total viscosity. Results from CBF studies proved nasal safety for the novel conjugate. According to these results, entirely preactivated thiolated xanthan gum seems to be a promising excipient for nasal dosage forms in order to improve drug bioavailability. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Gelled electrolytes for use in absorptive glass mat valve-regulated lead-acid (AGM VRLA) batteries working under 100% depth of discharge conditions

    NASA Astrophysics Data System (ADS)

    Tantichanakul, Titiporn; Chailapakul, Orawon; Tantavichet, Nisit

    2011-10-01

    Gelled electrolytes prepared from fumed silica for use in absorptive glass mat valve-regulated lead-acid (AGM VRLA) batteries and the effect of veratraldehyde addition on the electrochemical behavior and performance of AGM VRLA batteries are investigated. Cyclic voltammetry is used to investigate differences in the electrochemical behaviors of nongelled and gelled electrolytes and between gelled electrolytes with and without veratraldehyde. Battery performance is tested under 100% depth of discharge (100% DoD) conditions at both low- (0.1 C) and high- (1 C) rate discharges. The addition of silica or veratraldehyde does not affect the main reaction of the lead-acid batteries but tends to suppress the hydrogen evolution reaction. AGM VRLA batteries with gelled electrolytes have a higher discharge capacity and longer cycle life than the conventional nongel AGM VRLA batteries. The addition of 0.005% (w/v) veratraldehyde further improves battery performance, but higher (0.01%, w/v) veratraldehyde concentrations reduce it and correlate with the enhanced growth of lead sulfate crystals. The AGM VRLA battery prepared from a gelled electrolyte containing 0.005% (w/v) veratraldehyde provides the best battery performance in every operating temperature studied (0-60 °C).

  2. Metallized Gelled Propellants: Heat Transfer of a Rocket Engine Fueled by Oxygen/RP-1/Aluminum Was Measured by a Calorimeter

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    1998-01-01

    A set of analyses was conducted to determine the heat transfer characteristics of metallized gelled liquid propellants in a rocket engine. These analyses used data from experiments conducted with a small 30- to 40-lbf thrust engine composed of a modular injector, igniter, chamber, and nozzle. The fuels used were traditional liquid RP-1 and gelled RP-1 with 0-, 5-, and 55-wt % loadings of aluminum (Al) with gaseous oxygen as the oxidizer. Heat transfer measurements were made with a calorimeter chamber and nozzle setup that had a total of 31 cooling channels. A gelled fuel coating, composed of unburned gelled fuel and partially combusted RP-1, formed in the 0-, 5- and 55-wt % engines. For the 0- and 5-wt % RP-1/Al, the coating caused a large decrease in calorimeter engine heat flux in the last half of the chamber. This heat flux reduction was analyzed by comparing engine firings and the changes in the heat flux during a firing at NASA Lewis Research Center's Rocket Laboratories. This work is part of an ongoing series of analyses of metallized gelled propellants.

  3. Smart gelation of chitosan solution in the presence of NaHCO3 for injectable drug delivery system.

    PubMed

    Liu, Li; Tang, Ximin; Wang, Yuanyuan; Guo, Shengrong

    2011-07-29

    In situ gelling systems are attractive as injectable vehicles for drug delivery. The present work described a novel gelation process of acidic chitosan solution in the presence of sodium bicarbonate (NaHCO(3)). The NaHCO(3) concentration played an important role in this gelling system. When it came within the appropriate range, the chitosan/NaHCO(3) system would stay at sol state in certain condition and showed sol-gel transition from the top to the bottom after heating. The rheological properties of the gelling system, as well as the morphology and erosion behavior of the formed chitosan hydrogels were evaluated as a function of the NaHCO(3) concentration in sols. The hydrogels showed porous morphologies with some diversification depending on the NaHCO(3) concentration, which also affected their erosion behaviors and drug release rates. Moreover, the gelation mechanism of such chitosan/NaHCO(3) system was studied and proposed as the formation of three-dimensional chitosan network with physical junctions thanks to the deprotonation of -NH(3)(+) in chitosan accompanying with the gradual neutralization between HCO(3)(-) and acid. In vivo gelation test was also performed by the dorsal subcutaneous injection of chitosan/NaHCO(3) solution in rat. The formation of in situ gels suggested such system promising applications in injectable drug delivery system.

  4. Hydromorphone Injection

    MedlinePlus

    ... Your doctor may adjust your dose of hydromorphone injection during your treatment, depending on how well your pain is controlled and on the side ... to have pain after you finish the hydromorphone injection, call your doctor.It ... you are taking, as well as any products such as vitamins, minerals, or ...

  5. Ixabepilone Injection

    MedlinePlus

    ... doctor will order laboratory tests to see how well your liver is working before and during your treatment. If the tests show that you have liver problems, your doctor will probably not give you ixabepilone injection and capecitabine (Xeloda). Treatment with both ixabepilone injection ...

  6. Romidepsin Injection

    MedlinePlus

    ... group of cancers of the immune system that first appear as skin rashes) in people who have already been treated with at least one other medication given by mouth or by injection. Romidepsin injection is in a class of medications called histone deacetylase (HDAC) inhibitors. It ...

  7. Nusinersen Injection

    MedlinePlus

    Nusinersen injection is used for the treatment of spinal muscular atrophy (an inherited condition that reduces muscle strength and movement). Nusinersen injection is in a class of medications called antisense ... a certain protein necessary for the muscles and nerves to work normally.

  8. Banquet Speech at the Singapore Conference in Honour of Murray Gell-Mann on His 80th Birthday

    NASA Astrophysics Data System (ADS)

    Yang, Chen Ning

    2013-05-01

    It was about 60 years ago in 1951 that I first met in Princeton, at the Institute for Advanced Study, our Honoree tonight, Murray Gell-Mann. In the intervening 60 years, man's understanding of the fundamental structure of matter has made great historic advances. At this wonderful Conference, we have the opportunity to review some of these historic advances. It is a little like looking over an old album of memorable photographs in one's lifetime. In many of these photographs, Murray appears either in the foreground, or as the photographer snapping the picture. We know he is pleased with the album...

  9. Floating drug delivery of a locally acting H2-antagonist: an approach using an in situ gelling liquid formulation.

    PubMed

    Rohith, Ganapati; Sridhar, Bhimagoni Keshavamurthy; Srinatha, Anegundha

    2009-09-01

    In the present work, a gastroretentive in situ gelling liquid formulation for controlled delivery of ranitidine was formulated using sodium alginate (low, medium and high viscosity grades), calcium carbonate (source of cations) and ranitidine. Prepared formulations were evaluated for viscosity, buoyancy lag time and buoyancy duration, drug content and in vitro drug release. Formulation variables such as concentration of sodium alginate, calcium carbonate and drug significantly affected the formulation viscosity, floating behavior and in vitro drug release. Analysis of the release pattern showed that the drug release from in situ gel followed a diffusion mechanism.

  10. Musculoskeletal Injection

    PubMed Central

    Wittich, Christopher M.; Ficalora, Robert D.; Mason, Thomas G.; Beckman, Thomas J.

    2009-01-01

    Patients commonly present to primary care physicians with musculoskeletal symptoms. Clinicians certified in internal medicine must be knowledgeable about the diagnosis and management of musculoskeletal diseases, yet they often receive inadequate postgraduate training on this topic. The musculoskeletal problems most frequently encountered in our busy injection practice involve, in decreasing order, the knees, trochanteric bursae, and glenohumeral joints. This article reviews the clinical presentations of these problems. It also discusses musculoskeletal injections for these problems in terms of medications, indications, injection technique, and supporting evidence from the literature. Experience with joint injection and the pharmacological principles described in this article should allow primary care physicians to become comfortable and proficient with musculoskeletal injections. PMID:19720781

  11. Development of rectal delivered thermo-reversible gelling film encapsulating a 5-fluorouracil hydroxypropyl-β-cyclodextrin complex.

    PubMed

    Wang, Lu-Lu; Zheng, Wen-Sheng; Chen, Shao-Hua; Han, Yan-Xing; Jiang, Jian-Dong

    2016-02-10

    We have developed a novel 5-Fluorouracil (5FU) formulation for rectal application to improve its therapeutic efficiency in colorectal cancer. The results indicated that 5FU formed an inclusion complex with Hydroxypropyl-β-Cyclodextrin (HP-β-CD). The stoichiometry of the complex was 1:1, with apparent stability constant of 100.4M(-1). After investigating physicochemical properties of the 5FU-HP-β-CD complex encapsulated with thermo-reversible gelling film, the optimized formulation P407/P188/HPMC/5FU-HP-β-CD (18.5/2.5/0.2/15%) was selected and evaluated. The result showed that the 5FU-HP-β-CD complex increased the solubility of 5FU, prolonged and enhanced its releasing. As compared to the raw drug, the transport efficiency of the 5FU-HP-β-CD complex itself or entrapped in thermo-reversible gelling film were respectively 7.3- and 6.8-fold increased, and the cellular uptake of 5-FU 4.9- and 5.4-fold elevated. There was no irritation or damage to rectal sites in the 10h treatment period. Therefore, this HP-β-CD based formulation might improve the therapeutic effect of 5FU on colon-rectal cancer.

  12. The effect of taste masking agents on in situ gelling pectin formulations for oral sustained delivery of paracetamol and ambroxol.

    PubMed

    Miyazaki, Shozo; Kubo, Wataru; Itoh, Kunihiko; Konno, Yasuhiro; Fujiwara, Mariko; Dairaku, Masatake; Togashi, Mitsuo; Mikami, Ryozo; Attwood, David

    2005-06-13

    The aim of this study was to examine the influence of polyhydric alcohols (taste masking agents) on the rheological properties of in situ gelling pectin formulations and on the in vitro and in vivo release of paracetamol and ambroxol from these formulations. Gelation of orally administered pectin solutions containing calcium in complexed form occurred on release of calcium in the acidic environment of the stomach. Inclusion of 10% (w/v) sorbitol in 2% (w/v) pectin sols reduced the viscosity and ensured Newtonian flow properties. Xylitol and mannitol in similar concentrations were less effective in reducing viscosity; sucrose increased viscosity and caused non-Newtonian flow. The in vitro release of paracetamol from 2% (w/v) pectin gels formulated with 10% (w/v) of sorbitol, erythritol, xylitol or mannitol, and of ambroxol from 2% (w/v) pectin gels containing 10% (w/v) sorbitol, followed diffusion-controlled kinetics. Pectin gels (2%, w/v) containing sorbitol (10%, w/v) sustained the release of paracetamol in the rat stomach and bioavailabilities of approximately 90% of those from an orally administered paracetamol syrup were achieved. Sustained release of ambroxol from in situ gelling formulations was achieved with pectin concentrations of 1.5 and 1% (w/v) and a sorbitol concentration of 10% (w/v).

  13. Effects of Beef Fat Replacement with Gelled Emulsion Prepared with Olive Oil on Quality Parameters of Chicken Patties

    PubMed Central

    2017-01-01

    The objective of this study was to investigate the effect of using gelled emulsion (olive oil 46%, inulin 9%, gelatin 3%) as fat replacer on some quality parameters of chicken patties. For this purpose GE, prepared with olive oil, gelatin and inulin was replaced with beef fat at a level of 0%, 25%, 50%, 100% (C, G25, G50, G100). In this study syneresis, thermal stability, centrifuge and creaming stability of gelled emulsion were analyzed. Chemical composition, technological paramerers (cooking yield, water holding capacity, diameter reduction, fat and moisture retention) and textural and sensory properites were evaluated in comparision to control patties. High thermal stability was recorded in GE (93%), also creaming stability results showed that GE protected its stability without any turbidity and separation of the layer. The complete replacement of beef fat with GE showed detrimental effect on all investigated cooking characteristics except fat retention. Replacement of beef fat with GE at a level of 50% resulted similar cooking characteristics with C samples. Color parameters of samples were affected by GE addition, higher CIE b* values observed with respect to GE concentration. The presence of GE significantly affected textural behaviors of samples (p<0.05). Our results showed that GE prepared with inulin and olive oil is a viable fat replacer for the manufacture of chicken patty. PMID:28747823

  14. Biochemical characteristics and gelling capacity of pectin from yellow passion fruit rind as affected by acid extractant nature.

    PubMed

    Yapo, Beda M

    2009-02-25

    The effects of acid extractant type on the yield and characteristics of pectin from yellow passion fruit (Passiflora edulis flavicarpa) rind was investigated by using citric, nitric, or sulfuric acids at different concentrations (10 mM and 30 mM) and pH (1.8 and 2.5). The results showed that not only concentration, but also acid type influenced the extracted pectin yields (3-14%, w/w). The yield of pectin extracted with citric acid was the lowest. Acid type and concentration affected the molecular characteristics of pectin, notably, the degree of esterification (29-73), galacturonic acid to rhamnose ratio (14-35), weight average-molecular weight (100-250 kDa), gel strength (127-179), and setting time (841-1236 s). Citric acid-extracted pectin had a higher degree of esterification and weight average-molecular weight and better gelling properties. At 30 mM concentration, nitric and sulfuric acids solubilize pectins having a degree of esterification <50, contrary to citric acid. The results indicate that the latter acid exerts the least deesterifying action on pectin solubilization from the cell wall material. Citric acid-extracted pectin was closer to lemon pectin of similar degree of esterification in terms of gelling properties.

  15. Changes in physical and gelling properties of freeze-dried egg white as a result of temperature and relative humidity.

    PubMed

    Katekhong, Wattinee; Charoenrein, Sanguansri

    2016-10-01

    The quality of dried egg white with respect to functional properties can be affected by storage conditions. The effect of temperature and relative humidity (RH) on changes in colour and gelling properties in freeze-dried egg white (FDEW) during storage was investigated. The glass transition temperature (Tg ) of FDEW decreased with increasing % RH. The colour of FDEW stored at 60 °C was darker yellow than those at 40 and 25 °C, particularly at high % RH. RH had no effect on hardness and water-holding capacity (WHC) of gels made from FDEW stored at 25 °C for 1 week. However, hardness and WHC of gels from FDEW stored at higher temperatures; 40 °C, 48% RH and 60 °C, 11% RH dramatically increased. These results related to the differential scanning calorimeter thermograms which showed a broadening peak with lower enthalpy of protein denaturation. Moreover, the protein's SDS-PAGE pattern in the samples stored at high temperatures or RH levels showed protein aggregation. Storage of FDEW at high temperature and RH levels induced protein conformation changes. These have contributed to protein aggregation which affected the gelling properties of FDEW. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  16. Hp-β-CD-Voriconazole In Situ Gelling System for Ocular Drug Delivery: In Vitro, Stability, and Antifungal Activities Assessment

    PubMed Central

    Pawar, Pravin; Kashyap, Heena; Malhotra, Sakshi; Sindhu, Rakesh

    2013-01-01

    The objective of the present study was to design ophthalmic delivery systems based on polymeric carriers that undergo sol-to-gel transition upon change in temperature or in the presence of cations so as to prolong the effect of HP-β-CD Voriconazole (VCZ) in situ gelling formulations. The in situ gelling formulations of Voriconazole were prepared by using pluronic F-127 (PF-127) or with combination of pluronic F-68 (PF-68) and sodium alginate by cold method technique. The prepared formulations were evaluated for their physical appearance, drug content, gelation temperature (Tgel), in vitro permeation studies, rheological properties, mucoadhesion studies, antifungal studies, and stability studies. All batches of in situ formulations had satisfactory pH ranging from 6.8 to 7.4, drug content between 95% and 100%, showing uniform distribution of drug. As the concentration of each polymeric component was increased, that is, PF-68 and sodium alginate, there was a decrease in Tgel with increase in viscosity and mucoadhesive strength. The in vitro drug release decreased with increase in polymeric concentrations. The stability data concluded that all formulations showed the low degradation and maximum shelf life of 2 years. The antifungal efficiency of the selected formulation against Candida albicans and Asperigillus fumigatus confirmed that designed formulation has prolonged effect and retained its properties against fungal infection. PMID:23762839

  17. Thermoresponsive gelling behavior of concentrated alumina suspensions containing poly(acrylic acid) and PEO-PPO-PEO copolymer.

    PubMed

    Kondo, Akira; Xu, Hui; Abe, Hiroya; Naito, Makio

    2012-05-01

    Thermoresponsive gelling behavior of concentrated alumina suspensions with poly(acrylic acid) (PAA) and triblock copolymer (PEO(101)-PPO(56)-PEO(101), Pluronic F127) was investigated as a function of PAA concentration (0.4-1.2 mass%) for ceramic solid free forming. The copolymer species assemble into micelles at temperatures above 15°C, yielding aqueous physical gel. In this study, the concentrated alumina aqueous suspensions (φ=35 vol%) were first prepared using the anionic dispersant of PAA, and then the copolymer species (10 mass%) were dissolved at a cooled temperature at 10°C. The addition of the copolymer species had a negligible influence on the adsorption state of PAA onto the alumina surfaces. The PAA concentration needed for the saturation adsorption on the alumina surfaces was ~0.6 mass%. When the PAA concentration was this value or slightly less, the suspension became gel state at 30°C from low viscous state at 10°C. The thermally induced alumina gel had excellent viscoelastic properties, and thereby the three dimensional periodic ceramic structures were successfully fabricated by a direct colloidal printing method that using the gels as "solid" inks at the room temperature. On the other hand, when it exceeded the saturation adsorption limit, the gelling behavior was not observed, indicating that the non-adsorbing PAA species may partly suppress the micellization of the copolymer on the heating.

  18. Effects of Beef Fat Replacement with Gelled Emulsion Prepared with Olive Oil on Quality Parameters of Chicken Patties.

    PubMed

    Serdaroğlu, Meltem; Nacak, Berker; Karabıyıkoğlu, Merve

    2017-01-01

    The objective of this study was to investigate the effect of using gelled emulsion (olive oil 46%, inulin 9%, gelatin 3%) as fat replacer on some quality parameters of chicken patties. For this purpose GE, prepared with olive oil, gelatin and inulin was replaced with beef fat at a level of 0%, 25%, 50%, 100% (C, G25, G50, G100). In this study syneresis, thermal stability, centrifuge and creaming stability of gelled emulsion were analyzed. Chemical composition, technological paramerers (cooking yield, water holding capacity, diameter reduction, fat and moisture retention) and textural and sensory properites were evaluated in comparision to control patties. High thermal stability was recorded in GE (93%), also creaming stability results showed that GE protected its stability without any turbidity and separation of the layer. The complete replacement of beef fat with GE showed detrimental effect on all investigated cooking characteristics except fat retention. Replacement of beef fat with GE at a level of 50% resulted similar cooking characteristics with C samples. Color parameters of samples were affected by GE addition, higher CIE b* values observed with respect to GE concentration. The presence of GE significantly affected textural behaviors of samples (p<0.05). Our results showed that GE prepared with inulin and olive oil is a viable fat replacer for the manufacture of chicken patty.

  19. Abaloparatide Injection

    MedlinePlus

    ... of a natural human hormone called parathyroid hormone (PTH). It works by causing the body to build ... container.You should know that abaloparatide injection may cause dizziness, lightheadedness, and fainting when you get up ...

  20. Sumatriptan Injection

    MedlinePlus

    ... accompanied by nausea and sensitivity to sound and light). Sumatriptan injection is also used to treat the ... children. Store it at room temperature, away from light, excess heat, and moisture (not in the bathroom). ...

  1. Certolizumab Injection

    MedlinePlus

    ... has not improved when treated with other medications, rheumatoid arthritis (a condition in which the body attacks its ... continues. When certolizumab injection is used to treat rheumatoid arthritis, it is usually given every other week and ...

  2. Acyclovir Injection

    MedlinePlus

    ... chickenpox in the past) in people with weak immune systems. It is also used to treat first-time ... from time to time) in people with normal immune systems. Acyclovir injection is used to treat herpes simplex ...

  3. Doxercalciferol Injection

    MedlinePlus

    Doxercalciferol injection is used to treat secondary hyperparathyroidism (a condition in which the body produces too much parathyroid hormone [PTH; a natural substance needed to control the amount of calcium in ...

  4. Evolocumab Injection

    MedlinePlus

    ... how to inject this medication.Remove the prefilled syringe or prefilled autoinjector from the refrigerator and allow it to ... before using it. Do not warm the prefilled syringe or prefilled autoinjector in hot water, microwave, or place in ...

  5. Ixekizumab Injection

    MedlinePlus

    ... as a as a solution (liquid) in a prefilled syringe, and as a prefilled autoinjector to inject subcutaneously ( ... dispose of the puncture-resistant container.Remove the prefilled syringe or autoinjector from the refrigerator. Place it on ...

  6. Alirocumab Injection

    MedlinePlus

    ... how to inject this medication.Remove the prefilled syringe or prefilled dosing pen from the refrigerator and allow it ... hours or longer. Do not put the prefilled syringe or prefilled dosing pen back in the refrigerator after it ...

  7. Daclizumab Injection

    MedlinePlus

    Daclizumab comes as a solution (liquid) in a prefilled syringe to inject subcutaneously (under the skin). It is ... or tattooed.Never reuse or share needles or prefilled syringes of medication. Throw away used syringes in a ...

  8. Sarilumab Injection

    MedlinePlus

    ... receive any vaccines. You should not receive any vaccinations while you are using sarilumab injection without talking ... pregnant, tellyour doctor before the baby receives any vaccinations.if you are having surgery, including dental surgery, ...

  9. Zidovudine Injection

    MedlinePlus

    ... zidovudine injection does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) ... sex and making other life-style changes may decrease the risk of transmitting (spreading) the HIV virus ...

  10. Rasburicase Injection

    MedlinePlus

    ... as tumors break down) in people with certain types of cancer who are being treated with chemotherapy medications. Rasburicase injection is in a class of medications called enzymes. It works by breaking down uric acid so ...

  11. Haloperidol Injection

    MedlinePlus

    ... release injection are used to treat schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of ... medications); medications for anxiety, depression, irritable bowel disease, mental illness, motion sickness, Parkinson's disease, seizures, ulcers, or urinary ...

  12. Risperidone Injection

    MedlinePlus

    ... acting) injection is used to treat schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of ... ropinirole (Requip); medications for anxiety, blood pressure, or mental illness; medications for seizures such as carbamazepine (Carbatrol, Epitol, ...

  13. Thiotepa Injection

    MedlinePlus

    ... that begins in the female reproductive organs where eggs are formed), breast, and bladder cancer. It is ... comes as a powder to be mixed with liquid to be injected intravenously (into a vein) by ...

  14. Methotrexate Injection

    MedlinePlus

    ... Methotrexate injection is also used to treat severe psoriasis (a skin disease in which red, scaly patches ... slowing the growth of cancer cells. Methotrexate treats psoriasis by slowing the growth of skin cells to ...

  15. Cefazolin Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including skin, bone, joint, genital, blood, heart valve, ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefazolin injection will not work ...

  16. Trastuzumab Injection

    MedlinePlus

    ... completed for up to 52 weeks. When trastuzumab injection is used to treat stomach cancer, it is usually given once every 3 weeks. The length of your treatment depends on how well your body responds to the medication and the ...

  17. Bendamustine Injection

    MedlinePlus

    ... leukemia (CLL; a type of cancer of the white blood cells). Bendamustine injection is also used to treat a ... NHL: cancer that begins in a type of white blood cell that normally fights infection) that is slow spreading, ...

  18. Palonosetron Injection

    MedlinePlus

    ... that may occur several days after receiving certain chemotherapy medications. Palonosetron injection is in a class of medications called 5-HT3 receptor antagonists. It works by blocking the action of serotonin, a natural ...

  19. Doxycycline Injection

    MedlinePlus

    ... injection is in a class of medications called tetracycline antibiotics. It works by killing bacteria that cause ... are allergic to doxycycline, minocycline (Dynacin, Minocin, Solodyn), tetracycline (Achromycin V), any other medications, or any of ...

  20. Dexamethasone Injection

    MedlinePlus

    ... severe allergic reactions. It is used in the management of certain types of edema (fluid retention and ... needed for normal body functioning) and in the management of certain types of shock. Dexamethasone injection is ...

  1. Levofloxacin Injection

    MedlinePlus

    ... infections. Levofloxacin injection is also used to prevent anthrax (a serious infection that may be spread on ... in people who may have been exposed to anthrax germs in the air and treat and prevent ...

  2. Omalizumab Injection

    MedlinePlus

    ... steroids. Omalizumab is also used to treat chronic hives without a known cause that cannot successfully be ... is not used to treat other forms of hives or allergic conditions. Omalizumab injection is in a ...

  3. Plerixafor Injection

    MedlinePlus

    ... used along with a granulocyte-colony stimulating factor (G-CSF) medication such as filgrastim (Neupogen) or pegfilgrastim ( ... injection will begin after you have received a G-CSF medication once a day for 4 days, ...

  4. Avelumab Injection

    MedlinePlus

    ... doctor or nurse in a medical facility or infusion center. It is usually given once every 2 ... Avelumab injection may cause serious reactions during the infusion of the medication. You may be given other ...

  5. Alemtuzumab Injection

    MedlinePlus

    ... injection, the medication is usually given three times weekly on alternate days (usually Monday, Wednesday, and Friday) ... that you eat foods that are rich in iron such as meats, leafy green vegetables, and fortified ...

  6. Dinutuximab Injection

    MedlinePlus

    ... treat neuroblastoma (a cancer that begins in nerve cells) in children who have responded to other treatments. Dinutuximab injection is in a class of medications called monoclonal antibodies. It works by killing cancer cells.

  7. Cyclosporine Injection

    MedlinePlus

    ... transplanted organ by the immune system of the person receiving the organ) in people who have received kidney, liver, and heart transplants. Cyclosporine injection should only be used to treat people who are unable to take cyclosporine by mouth. ...

  8. Denosumab Injection

    MedlinePlus

    ... menstrual periods), who have an increased risk for fractures (broken bones) or who cannot take or did ... receiving certain treatments that increase their risk for fractures. Denosumab injection (Xgeva) is used to reduce fractures ...

  9. Epinephrine Injection

    MedlinePlus

    ... emergency medical treatment to treat life-threatening allergic reactions caused by insect bites or stings, foods, medications, ... at the first sign of a serious allergic reaction. Use epinephrine injection exactly as directed; do not ...

  10. Aflibercept Injection

    MedlinePlus

    ... injection is used to treat wet age-related macular degeneration (AMD; an ongoing disease of the eye that ... that leads to blurry vision and vision loss), diabetic macular edema (an eye disease caused by diabetes that can ...

  11. Fondaparinux Injection

    MedlinePlus

    ... the leg), which can lead to pulmonary embolism (PE; a blood clot in the lung), in people ... with warfarin (Coumadin, Jantoven) to treat DVT or PE. Fondaparinux injection is in a class of medications ...

  12. Panitumumab Injection

    MedlinePlus

    ... as a solution (liquid) to be given by infusion (injected into a vein). It is usually given ... doctor or nurse in a doctor's office or infusion center. Panitumumab is usually given once every 2 ...

  13. Topotecan Injection

    MedlinePlus

    ... organs where eggs are formed) and small cell lung cancer (a type of cancer that begins in the ... topotecan injection is used to treat ovarian or lung cancer, it is usually given once a day for ...

  14. Gemcitabine Injection

    MedlinePlus

    ... with surgery. Gemcitabine is also used to treat cancer of the pancreas that has spread to other parts of the ... 4 weeks. When gemcitabine is used to treat cancer of pancreas it may be injected once every week. The ...

  15. Lacosamide Injection

    MedlinePlus

    ... with other medications to control certain types of seizures in people who cannot take oral medications. Lacosamide ... If you suddenly stop using lacosamide injection, your seizures may happen more often. Your doctor will probably ...

  16. Pegloticase Injection

    MedlinePlus

    ... doctor if you have glucose-6-phosphate dehydrogenase (G6PD) deficiency (an inherited blood disease). Your doctor may test you for G6PD deficiency before you start to receive pegloticase injection. If ...

  17. Ibritumomab Injection

    MedlinePlus

    ... is in a class of medications called monoclonal antibodies with radioisotopes. It works by attaching to cancer ... you receive ibritumomab injection, your body may develop antibodies (substances in the blood that help the immune ...

  18. Oxytocin Injection

    MedlinePlus

    Oxytocin injection is used to begin or improve contractions during labor. Oxytocin also is used to reduce bleeding after childbirth. ... other medications or procedures to end a pregnancy. Oxytocin is in a class of medications called oxytocic ...

  19. Edaravone Injection

    MedlinePlus

    Edaravone injection is used to treat amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease; a condition in which the nerves that control muscle movement slowly die, causing the muscles to shrink and ...

  20. Pentamidine Injection

    MedlinePlus

    Pentamidine injection is used to treat pneumonia caused by a fungus called Pneumocystis carinii. It is in a class of medications called antiprotozoals. It works by stopping the growth of protozoa that can cause pneumonia.

  1. Diphenhydramine Injection

    MedlinePlus

    ... or along with other medications to control abnormal movements in people who have Parkinsonian syndrome (a disorder of the nervous system that causes difficulties with movement, muscle control, and balance). Diphenhydramine injection should not ...

  2. Docetaxel Injection

    MedlinePlus

    ... allergic to docetaxel injection or drugs made with polysorbate 80, an ingredient found in some medications. Ask ... if a medication you are allergic to contains polysorbate 80. If you experience any of the following ...

  3. Octreotide Injection

    MedlinePlus

    ... hormone (a natural substance) produced by people with acromegaly (condition in which the body produces too much ... Octreotide long-acting injection is used to control acromegaly, carcinoid tumors, and VIP-omas in people who ...

  4. Vedolizumab Injection

    MedlinePlus

    ... injection may cause serious allergic reactions during an infusion and for several hours afterward. A doctor or ... of the following symptoms during or after your infusion: rash; itching; swelling of the face, eyes, mouth, ...

  5. Granisetron Injection

    MedlinePlus

    ... that may occur after surgery. Granisetron extended-release (long-acting) injection is used with other medications to prevent nausea and vomiting caused by cancer chemotherapy that may occur immediately ...

  6. Fluconazole Injection

    MedlinePlus

    ... injection is used to treat fungal infections, including yeast infections of the mouth, throat, esophagus (tube leading ... by fungus. Fluconazole is also used to prevent yeast infections in patients who are likely to become ...

  7. Intravitreal injection

    MedlinePlus

    ... You may have this procedure if you have: Macular degeneration : An eye disorder that slowly destroys sharp, central ... injection References American Academy of Ophthalmology. Age-related macular degeneration PPP - updated 2015. Aao.org web site. Updated ...

  8. Ciprofloxacin Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria such as pneumonia; and infections of the skin, ... of antibiotics called fluoroquinolones. It works by killing bacteria that cause infections.Antibiotics such as ciprofloxacin injection ...

  9. Tobramycin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as tobramycin injection will not work ...

  10. Ceftriaxone Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria such as gonorrhea (a sexually transmitted disease), pelvic ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftriaxone injection will not work ...

  11. Moxifloxacin Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria such as pneumonia; ; and , skin, and abdominal (stomach ... antibiotics called fluoroquinolones. It works by killing the bacteria that cause infections.Antibiotics such as moxifloxacin injection ...

  12. Daptomycin Injection

    MedlinePlus

    ... in adults or serious skin infections caused by bacteria in adults and children 1 year of age ... called cyclic lipopeptide antibiotics. It works by killing bacteria.Antibiotics such as daptomycin injection will not work ...

  13. Amikacin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as amikacin injection will not work ...

  14. Meropenem Injection

    MedlinePlus

    ... skin and abdominal (stomach area) infections caused by bacteria and meningitis (infection of the membranes that surround ... of medications called antibiotics. It works by killing bacteria that cause infection.Antibiotics such as meropenem injection ...

  15. Cefepime Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including pneumonia, and skin, urinary tract, and kidney ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefepime injection will not work ...

  16. Ertapenem Injection

    MedlinePlus

    ... abdominal (stomach area) infections, that are caused by bacteria. It is also used for the prevention of ... medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as ertapenem injection will not work ...

  17. Aztreonam Injection

    MedlinePlus

    ... to treat certain infections that are caused by bacteria, including respiratory tract (including pneumonia and bronchitis), urinary ... abdominal (stomach area) infections, that are caused by bacteria. Aztreonam injection also may be used before, during, ...

  18. Ceftaroline Injection

    MedlinePlus

    ... infections and pneumonia (lung infection) caused by certain bacteria. Ceftaroline is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftaroline injection will not work ...

  19. Cefotaxime Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including pneumonia and other lower respiratory tract (lung) ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefotaxime injection will not work ...

  20. Cefuroxime Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including pneumonia and other lower respiratory tract (lung) ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefuroxime injection will not work ...

  1. Ampicillin Injection

    MedlinePlus

    ... to treat certain infections that are caused by bacteria such as meningitis (infection of the membranes that ... of medications called penicillins. It works by killing bacteria.Antibiotics such as ampicillin injection will not work ...

  2. Gentamicin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as gentamicin injection will not work ...

  3. MEDICAL INJECTION

    NASA Image and Video Library

    1963-06-10

    S62-08371 (1962) --- The automatic medical injectors carried on the Mercury-Atlas 9 flight. The injectors provide the astronaut with injection tubes of Tigan, for preventing motion sickness and Demerol, for relieving pain. The tubes encased in the block are stowed in the astronauts survival kit. The single injection tubes are placed in a pocket of the astronauts spacesuit. Photo credit: NASA

  4. Injection overview

    SciTech Connect

    Prestwich, S.

    1983-12-01

    The test program was initiated at the Raft River Geothermal Field in southern Idaho in September 1982. A series of eight short-term injection and backflow tests, followed by a long-term injection test, were conducted on one well in the field. Tracers were added during injection and monitored during backflow as well. The principal objective was to determine if tracers could be effectively used as a means to assess reservoir characteristics in a one-well test. The test program resulted in a unique data set which shows promise as a means to improve understanding of the reservoir characteristics. In December 1982, an RFP was issued to obtain an industrial partner to obtain follow-on data on the injection/backflow technique in a second field, and to study any alternate advanced concepts for injection testing which the industrial community might recommend. The East Mesa Geothermal Field was selected for the second test series. Two wells were utilized for testing, and a series of ten tests were conducted in July and August 1983, aimed principally at further evaluation of the injection/backflow technique.

  5. Salivary enzymes are injected into xylem by the glassy-winged sharpshooter, a vector of Xylella fastidiosa.

    PubMed

    Backus, Elaine A; Andrews, Kim B; Shugart, Holly J; Carl Greve, L; Labavitch, John M; Alhaddad, Hasan

    2012-07-01

    A few phytophagous hemipteran species such as the glassy-winged sharpshooter, Homalodisca vitripennis, (Germar), subsist entirely on xylem fluid. Although poorly understood, aspects of the insect's salivary physiology may facilitate both xylem-feeding and transmission of plant pathogens. Xylella fastidiosa is a xylem-limited bacterium that causes Pierce's disease of grape and other scorch diseases in many important crops. X. fastidiosa colonizes the anterior foregut (precibarium and cibarium) of H. vitripennis and other xylem-feeding vectors. Bacteria form a dense biofilm anchored in part by an exopolysaccharide (EPS) matrix that is reported to have a β-1,4-glucan backbone. Recently published evidence supports the following, salivation-egestion hypothesis for the inoculation of X. fastidiosa during vector feeding. The insect secretes saliva into the plant and then rapidly takes up a mixture of saliva and plant constituents. During turbulent fluid movements in the precibarium, the bacteria may become mechanically and enzymatically dislodged; the mixture is then egested back out through the stylets into plant cells, possibly including xylem vessels. The present study found that proteins extracted from dissected H. vitripennis salivary glands contain several enzyme activities capable of hydrolyzing glycosidic linkages in polysaccharides such as those found in EPS and plant cell walls, based on current information about the structures of those polysaccharides. One of these enzymes, a β-1,4-endoglucanase (EGase) was enriched in the salivary gland protein extract by subjecting the extract to a few, simple purification steps. The EGase-enriched extract was then used to generate a polyclonal antiserum that was used for immunohistochemical imaging of enzymes in sharpshooter salivary sheaths in grape. Results showed that enzyme-containing gelling saliva is injected into xylem vessels during sharpshooter feeding, in one case being carried by the transpiration stream away

  6. Physical barriers formed from gelling liquids: 1. numerical design of laboratory and field experiments

    SciTech Connect

    Finsterle, S.; Moridis, G.J.; Pruess, K.; Persoff, P.

    1994-01-01

    The emplacement of liquids under controlled viscosity conditions is investigated by means of numerical simulations. Design calculations are performed for a laboratory experiment on a decimeter scale, and a field experiment on a meter scale. The purpose of the laboratory experiment is to study the behavior of multiple gout plumes when injected in a porous medium. The calculations for the field trial aim at designing a grout injection test from a vertical well in order to create a grout plume of a significant extent in the subsurface.

  7. Immunization of chickens with an agonistic monoclonal anti-chicken CD40 antibody-hapten complex: rapid and robust IgG response induced by a single subcutaneous injection.

    PubMed

    Chen, Chang-Hsin; Abi-Ghanem, Daad; Waghela, Suryakant D; Chou, Wen-Ko; Farnell, Morgan B; Mwangi, Waithaka; Berghman, Luc R

    2012-04-30

    Producing diagnostic antibodies in chicken egg yolk represents an alternate animal system that offers many advantages including high productivity at low cost. Despite being an excellent counterpart to mammalian antibodies, chicken IgG from yolk still represents an underused resource. The potential of agonistic monoclonal anti-CD40 antibodies (mAb) as a powerful immunological adjuvant has been demonstrated in mammals, but not in chickens. We recently reported an agonistic anti-chicken CD40 mAb (designated mAb 2C5) and showed that it may have potential as an immunological adjuvant. In this study, we examined the efficacy of targeting a short peptide to chicken CD40 [expressed by the antigen-presenting cells (APCs)] in enhancing an effective IgG response in chickens. For this purpose, an immune complex consisting of one streptavidin molecule, two directionally biotinylated mAb 2C5 molecules, and two biotinylated peptide molecules was produced. Chickens were immunized subcutaneously with doses of this complex ranging from 10 to 90 μg per injection once, and relative quantification of the peptide-specific IgG response showed that the mAb 2C5-based complex was able to elicit a strong IgG response as early as four days post-immunization. This demonstrates that CD40-targeting antigen to chicken APCs can significantly enhance antibody responses and induce immunoglobulin isotype-switching. This immunization strategy holds promise for rapid production of hapten-specific IgG in chickens.

  8. A novel method for the rapid determination of polyethoxylated tallow amine surfactants in water and sediment using large volume injection with high performance liquid chromatography and tandem mass spectrometry.

    PubMed

    Ross, Andrew R S; Liao, Xiangjun

    2015-08-19

    Polyethoxylated tallow amine (POEA) surfactants have been used in many glyphosate-based herbicide formulations for agricultural, industrial and residential weed control. The potential for release of these compounds into the environment is of increasing concern due to their toxicity towards aquatic organisms. Current methods for analysis of POEA surfactants require significant time and effort to achieve limits of quantification that are often higher than the concentrations at which biological effects have been observed (as low as 2 ng mL(-1)). We have developed a rapid and robust method for quantifying the POEA surfactant mixture MON 0818 at biologically relevant concentrations in fresh water, sea water and lake sediment using reversed phase high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry. Water samples preserved by 1:1 v/v dilution with methanol are analyzed directly following centrifugation. Sediment samples undergo accelerated solvent extraction in aqueous methanol prior to analysis. Large volume (100 μL) sample injection and multiple reaction monitoring of a subset of the most abundant POEA homologs provide limits of quantification of 0.5 and 2.9 ng mL(-1) for MON 0818 in fresh water and sea water, respectively, and 2.5 ng g(-1) for total MON 0818 in lake sediment. Average recoveries of 93 and 75% were achieved for samples of water and sediment, respectively spiked with known amounts of MON 0818. Precision and accuracy for the analysis of water and sediment samples were within 10 and 16%, respectively based upon replicate analyses of calibration standards and representative samples. Results demonstrate the utility of the method for quantifying undegraded MON 0818 in water and sediment, although a more comprehensive method may be needed to identify and determine other POEA mixtures and degradation profiles that might occur in the environment.

  9. Liquid methane gelled with methanol and water reduces rate of nitrogen absorption

    NASA Technical Reports Server (NTRS)

    Vanderwall, E. M.

    1972-01-01

    Dilution of gelant vapor with inert carrier gas accomplishes gelation. Mixture is injected through heated tube and orifice into liquid methane for immediate condensation within bulk of liquid. Direct dispersion of particles in liquid avoids condensation on walls of vessel and eliminates additional mixing.

  10. Ganciclovir Injection

    MedlinePlus

    ... tests to check your body's response to ganciclovir injection.It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or ...

  11. Pertuzumab Injection

    MedlinePlus

    ... tests to check your body's response to pertuzumab injection.It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or ...

  12. Mitoxantrone Injection

    MedlinePlus

    ... to the treatment.If you are using mitoxantrone injection for MS, you should know that it controls MS but does not cure it. Continue to receive treatments even if you feel well. Talk to your doctor if you no longer ...

  13. Olaratumab Injection

    MedlinePlus

    ... your pharmacist any questions you have about olaratumab injection.It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or ...

  14. Reslizumab Injection

    MedlinePlus

    ... the infusion or for a short period of time after the infusion has finished.You will receive each injection of reslizumab in a doctor's office or medical facility. You will stay in the office for some time after you receive the medication so your doctor ...

  15. Teduglutide Injection

    MedlinePlus

    ... syndrome in people who need additional nutrition or fluids from intravenous (IV) therapy. Teduglutide injection is in a class of medications called glucagon-like peptide-2 (GLP-2) analogs. It works by improving the absorption of fluids and nutrients in the intestines.

  16. Pegaptanib Injection

    MedlinePlus

    ... if you have or have ever had diabetes, high blood pressure, a heart attack, or a stroke.tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while using pegaptanib injection, ...

  17. Preparation and properties of embeddable Ag/AgCl gelling reference electrode for rebars corrosion monitoring in concrete

    NASA Astrophysics Data System (ADS)

    Tang, Yan-bing; Wang, Sheng-nian; Chen, Long; Fan, Zhi-hong

    2015-12-01

    Reference electrodes are a key part for corrosion monitoring and measurement of rebars in concrete. A reference electrode that can be buried in concrete is fabricated by using Ag/AgCl electrode and methyl cellulose gelling electrolyte. The stability, repeatability and anti-polarization of the reference electrode are investigated; the influences of the inner electrolyte loss, exterior OH- contamination, and temperature on the potential of the reference electrode are also investigated in this paper. The results show that the reference electrode has good stability, repeatability, and antipolarization. The influences of inner electrolyte loss, exterior OH- contamination, and temperature on the potential of the reference electrode are minimal. Therefore, it can be used for corrosion monitoring and measurement of rebars in concrete.

  18. Preparation and characterization of water/oil and water/oil/water emulsions containing biopolymer-gelled water droplets.

    PubMed

    Surh, Jeonghee; Vladisavljevi Cacute, Goran T; Mun, Saehun; McClements, D Julian

    2007-01-10

    The purpose of this study was to create water-in-oil (W/O) and water-in-oil-in-water (W/O/W) emulsions containing gelled internal water droplets. Twenty weight percent W/O emulsions stabilized by a nonionic surfactant (6.4 wt % polyglycerol polyricinoleate, PGPR) were prepared that contained either 0 or 15 wt % whey protein isolate (WPI) in the aqueous phase, with the WPI-containing emulsions being either unheated or heated (80 degrees C for 20 min) to gel the protein. Optical microscopy and sedimentation tests did not indicate any significant changes in droplet characteristics of the W/O emulsions depending on WPI content (0 or 15%), shearing (0-7 min at constant shear), thermal processing (30-90 degrees C for 30 min), or storage at room temperature (up to 3 weeks). W/O/W emulsions were produced by homogenizing the W/O emulsions with an aqueous Tween 20 solution using either a membrane homogenizer (MH) or a high-pressure valve homogenizer (HPVH). For the MH the mean oil droplet size decreased with increasing number of passes, whereas for the HPVH it decreased with increasing number of passes and increasing homogenization pressure. The HPVH produced smaller droplets than the MH, but the MH produced a narrower particle size distribution. All W/O/W emulsions had a high retention of water droplets (>95%) within the larger oil droplets after homogenization. This study shows that W/O/W emulsions containing oil droplets with gelled water droplets inside can be produced by using MH or HPVH.

  19. Subcutaneous (SQ) injections

    MedlinePlus

    SQ injections; Sub-Q injections; Diabetes subcutaneous injection; Insulin subcutaneous injection ... NIH. Giving a subcutaneous injection . Rockville, MD. National ... of Health and Human Services NIH publications; 2015. Available ...

  20. Perceived serosorting of injection paraphernalia sharing networks among injection drug users in Baltimore, MD.

    PubMed

    Yang, C; Tobin, K; Latkin, C

    2011-01-01

    We examined perceived serosorting of injection paraphernalia sharing networks among a sample of 572 injection drug users (IDUs). There was evidence for serosorting of high-risk injection behaviors among HIV-negative IDUs, as 94% of HIV-negative IDUs shared injection paraphernalia exclusively with perceived HIV-negative networks. However, 82% of HIV-positive IDUs shared injection paraphernalia with perceived HIV-negative networks. The findings indicate a potential risk of rapid HIV transmission. Future prevention efforts targeting IDUs should address the limitation of serosorting, and focus on preventing injection paraphernalia sharing regardless of potential sharing networks' perceived HIV status.

  1. PCL-based thermo-gelling polymers for in vivo delivery of chemotherapeutics to tumors.

    PubMed

    Zheng, Chaohui; Gao, Hongzhi; Yang, Da-Peng; Liu, Minghuan; Cheng, Hongwei; Wu, Yun-Long; Loh, Xian Jun

    2017-05-01

    The synthesis of a multiblock poly(ether ester urethane)s comprising poly(ε-caprolactone), poly(ethylene glycol), and poly(propylene glycol) segments is described. We found that this polymer possessed a critical thermo-gelation concentration of 4wt%. Molecular characterization of the polymer was performed in terms of molecular weight determination, chemical composition elucidation and functional group determination using GPC, NMR, and FTIR. We carried out in vitro paclitaxel and doxorubicin release studies and demonstrated that sustained therapeutic release of about 2weeks can be obtained with this system. A nude mice model of tumor was developed and intratumoral injection of therapeutic-loaded thermo-gel demonstrated that PTX-loaded thermo-gel effectively inhibited the growth of tumors. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Injectable biomaterials for stem cell delivery and tissue regeneration.

    PubMed

    Zhang, Zhanpeng

    2017-01-01

    Organ dysfunction and failure are major health issues affecting millions of patients, many of whom are desperate for organ transplantation. Tissue regeneration aims at providing alternative solutions through innovative application of cell biology and materials engineering to clinical practice. Biomaterials play a critical role in tissue engineering, which interface with both cell biology and surgical procedures. Injectable stem cell carriers represent a promising platform to harvest the therapeutic effects of cells and to simplify the surgical process. Areas covered: This review is focused on injectable cell carriers which are not only expected to improve therapeutic outcomes, but also to facilitate easy surgical process. Such cell carriers include in situ gelling hydrogel, injectable supramolecular hydrogels, and microcarriers. Expert opinion: The current design of hydrogels and microcarriers can achieve biocompatibility, biodegradability, and provide desirable features to enhance biological response. Overall, more systematic understanding of stem cell behaviors in a synthetic microenvironment, as well as advancement in materials sciences, are needed to design injectable biomaterials that can provide all critical guidance for the full course of tissue regeneration.

  3. Development of in vitro models to demonstrate the ability of PecSys®, an in situ nasal gelling technology, to reduce nasal run-off and drip.

    PubMed

    Castile, Jonathan; Cheng, Yu-Hui; Simmons, Ben; Perelman, Michael; Smith, Alan; Watts, Peter

    2013-05-01

    Many of the increasing number of intranasal products available for either local or systemic action can be considered sub-optimal, most notably where nasal drip or run-off give rise to discomfort/tolerability issues or reduced/variable efficacy. PecSys, an in situ gelling technology, contains low methoxy (LM) pectin which gels due to interaction with calcium ions present in nasal fluid. PecSys is designed to spray readily, only forming a gel on contact with the mucosal surface. The present study employed two in vitro models to confirm that gelling translates into a reduced potential for drip/run-off: (i) Using an inclined TLC plate treated with a simulated nasal electrolyte solution (SNES), mean drip length [±SD, n = 10] was consistently much shorter for PecSys (1.5 ± 0.4 cm) than non-gelling control (5.8 ± 1.6 cm); (ii) When PecSys was sprayed into a human nasal cavity cast model coated with a substrate containing a physiologically relevant concentration of calcium, PecSys solution was retained at the site of initial deposition with minimal redistribution, and no evidence of run-off/drip anteriorly or down the throat. In contrast, non-gelling control was significantly more mobile and consistently redistributed with run-off towards the throat. In both models PecSys significantly reduced the potential for run-off/drip ensuring that more solution remained at the deposition site. In vivo, this enhancement of retention will provide optimum patient acceptability, modulate drug absorption and maximize the ability of drugs to be absorbed across the nasal mucosa and thus reduce variability in drug delivery.

  4. Development of in vitro models to demonstrate the ability of PecSys®, an in situ nasal gelling technology, to reduce nasal run-off and drip

    PubMed Central

    2013-01-01

    Many of the increasing number of intranasal products available for either local or systemic action can be considered sub-optimal, most notably where nasal drip or run-off give rise to discomfort/tolerability issues or reduced/variable efficacy. PecSys, an in situ gelling technology, contains low methoxy (LM) pectin which gels due to interaction with calcium ions present in nasal fluid. PecSys is designed to spray readily, only forming a gel on contact with the mucosal surface. The present study employed two in vitro models to confirm that gelling translates into a reduced potential for drip/run-off: (i) Using an inclined TLC plate treated with a simulated nasal electrolyte solution (SNES), mean drip length [±SD, n = 10] was consistently much shorter for PecSys (1.5 ± 0.4 cm) than non-gelling control (5.8 ± 1.6 cm); (ii) When PecSys was sprayed into a human nasal cavity cast model coated with a substrate containing a physiologically relevant concentration of calcium, PecSys solution was retained at the site of initial deposition with minimal redistribution, and no evidence of run-off/drip anteriorly or down the throat. In contrast, non-gelling control was significantly more mobile and consistently redistributed with run-off towards the throat. Conclusion In both models PecSys significantly reduced the potential for run-off/drip ensuring that more solution remained at the deposition site. In vivo, this enhancement of retention will provide optimum patient acceptability, modulate drug absorption and maximize the ability of drugs to be absorbed across the nasal mucosa and thus reduce variability in drug delivery. PMID:22803832

  5. Optimization of a gelled emulsion intended to supply ω-3 fatty acids into meat products by means of response surface methodology.

    PubMed

    Poyato, Candelaria; Ansorena, Diana; Berasategi, Izaskun; Navarro-Blasco, Iñigo; Astiasarán, Iciar

    2014-12-01

    The optimization of a gelled oil-in-water emulsion was performed for use as fat replacer in the formulation of ω-3 PUFA-enriched cooked meat products. The linseed oil content, carrageenan concentration and surfactant-oil ratio were properly combined in a surface response design for maximizing the hardness and minimizing the syneresis of the PUFA delivery system. The optimal formulation resulted in a gelled emulsion containing 40% of oil and 1.5% of carrageenan, keeping a surfactant-oil ratio of 0.003. The gel was applied as a partial fat replacer in a Bologna-type sausage and compared to the use of an O/W emulsion also enriched in ω-3. Both experimental sausages contributed with higher ω-3 PUFA content than the control. No sensory differences were found among formulations. The selected optimized gelled oil-in-water emulsion was demonstrated to be a suitable lipophilic delivery system for ω-3 PUFA compounds and applicable in food formulations as fat replacer.

  6. Pineapple and banana pectins comprise fewer homogalacturonan building blocks with a smaller degree of polymerization as compared with yellow passion fruit and lemon pectins: implication for gelling properties.

    PubMed

    Yapo, Beda M

    2009-04-13

    Pectins are viewed as multiblock cobiopolymers of different pectic polysaccharides, notably, homogalacturonan (HG) and rhamnogalacturonan I (RG I). Furthermore, on the basis of HGs isolated from different (pectins from) dicot cell walls, HG is supposed to have an average degree of polymerization (DP) of approximately 100 irrespective of the plant source. To validate or invalidate these suppositions, pectins from both monocot (pineapple and banana) and dicot (yellow passion fruit and lemon) cell walls were examined. The results show that all the extracted pectins comprise HGs as well as type I and II arabinogalactan side chain-containing RGs I, but of significantly (p < 0.05) different relative proportions; lemon pectin being the richest in HGs, followed by yellow passion fruit pectin. The HG building blocks of each pectin are homogeneous with respect to the molecular size but have a significantly (p < 0.05) reduced length in monocot pectins (59-67) compared to dicot ones (93-102). Lemon pectin displayed the highest degree of esterification (DE), viscosity-average molecular weight (M(v)), and gelling ability, whereas with similar DEs and a higher M(v), banana pectin exhibited a lower gelling ability than yellow passion fruit pectin. It is concluded that both the HG amount and DP strongly influence the gelling properties of pectin.

  7. Musculoskeletal injections: a review of the evidence.

    PubMed

    Stephens, Mark B; Beutler, Anthony I; O'Connor, Francis G

    2008-10-15

    Injections are valuable procedures for managing musculoskeletal conditions commonly encountered by family physicians. Corticosteroid injections into articular, periarticular, or soft tissue structures relieve pain, reduce inflammation, and improve mobility. Injections can provide diagnostic information and are commonly used for postoperative pain control. Local anesthetics may be injected with corticosteroids to provide additional, rapid pain relief. Steroid injection is the preferred and definitive treatment for de Quervain tenosynovitis and trochanteric bursitis. Steroid injections can also be helpful in controlling pain during physical rehabilitation from rotator cuff syndrome and lateral epicondylitis. Intra-articular steroid injection provides pain relief in rheumatoid arthritis and osteoarthritis. There is little systematic evidence to guide medication selection for therapeutic injections. The medication used and the frequency of injection should be guided by the goal of the injection (i.e., diagnostic or therapeutic), the underlying musculoskeletal diagnosis, and clinical experience. Complications from steroid injections are rare, but physicians should understand the potential risks and counsel patients appropriately. Patients with diabetes who receive periarticular or soft tissue steroid injections should closely monitor their blood glucose for two weeks following injection.

  8. Helpful tips for performing musculoskeletal injections.

    PubMed

    Metz, John P

    2010-01-01

    Injections are valuable procedures for managing musculoskeletal conditions commonly encountered by family physicians. Corticosteroid injections into articular, periarticular, or soft tissue structures relieve pain, reduce inflammation, and improve mobility. Injections can provide diagnostic information and are commonly used for postoperative pain control. Local anesthetics may be injected with corticosteroids to provide additional, rapid pain relief. Steroid injection is the preferred and definitive treatment for de Quervain tenosynovitis and trochanteric bursitis. Steroid injections can also be helpful in controlling pain during physical rehabilitation from rotator cuff syndrome and lateral epicondylitis. Intra-articular steroid injection provides pain relief in rheumatoid arthritis and osteoarthritis. There is little systematic evidence to guide medication selection for therapeutic injections. The medication used and the frequency of injection should be guided by the goal of the injection (i.e., diagnostic or therapeutic), the underlying musculoskeletal diagnosis, and clinical experience. Complications from steroid injections are rare, but physicians should understand the potential risks and counsel patients appropriately. Patients with diabetes who receive periarticular or soft tissue steroid injections should closely monitor their blood glucose for two weeks following injection.

  9. An environmentally safe larvicide against Aedes aegypti based on in situ gelling nanostructured surfactant systems containing an essential oil.

    PubMed

    Ferreira, S G; Conceição, V S; Gouveia, N S; Santos, G S; Santos, R L C; Lira, A A M; Cavalcanti, S C H; Sarmento, V H V; Nunes, R S

    2015-10-15

    Liquid crystalline precursors, which are in situ gelling nanostructured surfactant systems, can undergo phase transition in aqueous solution and become more structured aggregates, controlling release of larvicides and acting as biotechnology alternatives for dengue control. Such systems can contain bioactive substances as Citrus sinensis essential oil (CSEO) which exhibits biological activity against Aedes aegypti (Ae. aegypti) larvae. The formulations were composed by fixed concentration of CSEO stabilized by Polyoxypropylene (5) Polyoxyethylene (20) Cetyl Ether (PPG-5 CETETH-20): oleic acid (OA) 2:1, increasing water content. The phase diagram was established and systems structure was evaluated by polarized light microscopy (PLM), small angle X-ray scattering (SAXS) and rheology. Median lethal concentration was determined against Ae. aegypti larvae. The phase diagram exhibited four regions: liquid crystal (LC), emulsion, microemulsion (ME) and phase separation. The PLM and SAXS distinguished microemulsions, lamellar and hexagonal LC structures. Flow and oscillatory tests showed that increasing water content increases elasticity from Newtonian to non-newtonian behavior confirming the in situ gelation behavior. The larvicidal activity of formulations indicates that these nanostructured systems improved the oil solubility in aqueous medium and in addition are potential environmental larvicide against Ae. aegypti larvae. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Study of hydroxy propyl guar derivative for its gelling property and it's use in the formulation of tenoxicam gels.

    PubMed

    Swamy, N G N; Dharmarajan, T S; Paranjothi, K L K

    2007-01-01

    Gels of tenoxicam 1% w/w were formulated using 2% w/w hydroxy propyl guar derivative and 3% w/w sodium carboxy methyl cellulose as gelling agents. A detailed rheological investigation was carried out to study the influence of preservative, drug and preservative, solvent system and the preservative, drug, solvent system and the preservative on the pseudoplastic behaviour of polymers. Hydroxy propyl guar derivative in 2% w/w strength resulted in gels with a higher pseudoplastic index value of 3.383 in contrast to an index value of 1.797 for a 3% w/w sodium carboxy methyl cellulose gels of a similar composition. The gels were stored at different temperatures and variations in pH values were recorded. Hydroxy propyl guar derivative based gels revealed variations in pH values over a narrow range in contrast to sodium carboxy methyl cellulose gels. The gels were subjected to short term stability studies by storing gels at refrigerated temperature, lab temperature, at 37 degrees C and at 45 degrees C. Gels based on hydroxy propyl guar derivative revealed better drug keeping qualities in contrast to sodium carboxy methyl cellulose stabilized gels. Release studies of tenoxicam from formulations across hairless albino mice skin revealed a zero order drug release pattern from both the formulations.

  11. Improvement in the in situ gelling properties of deacetylated gellan gum by the immobilization of thiol groups.

    PubMed

    Krauland, Alexander H; Leitner, Verena M; Bernkop-Schnürch, Andreas

    2003-06-01

    The rheological properties of an in situ crosslinking thiolated deacetylated gellan gum were examined in vitro. Mediated by a carbodiimide, L-cysteine was covalently bound to deacetylated gellan gum (DGG). The deacetylated gellan gum-cysteine (DGG-Cys) conjugate displayed 216.53 +/- 59.54 micromol thiol groups per gram polymer (means +/- SD, n = 3). The thiolated polymer was capable of forming inter- and/or intramolecular disulfide bonds in aqueous solution (1.5%; m/m) at pH 7. After 6 h of incubation at room temperature, storage modulus, loss modulus, and complex viscosity increased 300-, 6.4-, and 26.6-fold, respectively, relative to the unthiolated polymer. Loss tangent of DGG-Cys was <1, indicating a gel, whereas the corresponding unmodified polymer had a loss tangent of >1, indicating a fluid. Frequency sweep measurements demonstrated an increase in crosslinking of the thiolated polymer as a function of time. DGG-Cys appeared to be superior to the unmodified polymer also in the presence of physiological cation concentrations found (e.g., in tear fluid and nasal secretion), which is referred to rheological properties. The polymer generated within this study represents a promising novel excipient for various drug delivery systems in which in situ gelling properties are favorable.

  12. Simulations on the gelling process of particle suspension systems for in-situ preparing porous materials in a capillary

    NASA Astrophysics Data System (ADS)

    Wang, J.; Xu, J. J.; Yang, Y.; Wang, X. J.; Luo, X.; Zhang, L.; Jiang, G.

    2015-10-01

    The gelling process of particle suspension in a capillary which is crucial for in-situ preparing small size foam products has been simulated with an off-lattice diffusion limited cluster aggregation (DLCA) model by the three-dimensional Monte Carlo simulations. The effects of the model parameters, such as the interaction between capillary wall and particles, particle volume fraction, capillary size etc. on the density distribution of the system have been fully explored. And the aggregation kinetics process over a broad range of volume fractions and interactions have also been discussed. The results show that the geometric constraint of capillary can be analogous to a weak repulsive interaction between capillary wall and particles. And we found that as the capillary size or particle volume fraction increase, particle concentration distribution will be more uniform with other parameters constant. Porous network with relatively uniform density distribution can be also obtained through controlling the interaction between capillary wall and particles. In addition, by analyzing the aggregation kinetics process, we found that the attraction of capillary wall dramatically reduces the probability of gelation in the small-scale capillary. The obtained results will be of great importance in controlling the density distribution of porous materials prepared by in-situ methods.

  13. Sorption of Cu(II) Ions on Chitosan-Zeolite X Composites: Impact of Gelling and Drying Conditions.

    PubMed

    Djelad, Amal; Morsli, Amine; Robitzer, Mike; Bengueddach, Abdelkader; di Renzo, Francesco; Quignard, Françoise

    2016-01-19

    Chitosan-zeolite Na-X composite beads with open porosity and different zeolite contents were prepared by an encapsulation method. Preparation conditions had to be optimised in order to stabilize the zeolite network during the polysaccharide gelling process. Composites and pure reference components were characterized using X-ray diffraction (XRD); scanning electron microscopy (SEM); N₂ adsorption-desorption; and thermogravimetric analysis (TG). Cu(II) sorption was investigated at pH 6. The choice of drying method used for the storage of the adsorbent severely affects the textural properties of the composite and the copper sorption effectiveness. The copper sorption capacity of chitosan hydrogel is about 190 mg·g(-1). More than 70% of this capacity is retained when the polysaccharide is stored as an aerogel after supercrititcal CO₂ drying, but nearly 90% of the capacity is lost after evaporative drying to a xerogel. Textural data and Cu(II) sorption data indicate that the properties of the zeolite-polysaccharide composites are not just the sum of the properties of the individual components. Whereas a chitosan coating impairs the accessibility of the microporosity of the zeolite; the presence of the zeolite improves the stability of the dispersion of chitosan upon supercritical drying and increases the affinity of the composites for Cu(II) cations. Chitosan-zeolite aerogels present Cu(II) sorption properties.

  14. Thermosensitive and pH induced in situ ophthalmic gelling system for ciprofloxacin hydrochloride: hydroxypropyl-beta-cyclodextrin complex.

    PubMed

    Başaran, Berrin; Bozkir, Asuman

    2012-01-01

    The prolonged residence of drug formulation in the ocular cavity is important for ocular drug delivery. The purpose of the present study was to develop ophthalmic in situ gelling systems of ciprofloxacin hydrochloride with reduced pre-corneal elimination in order to improve the bioavailability and therapeutic response. Hydroxypropyl-beta-cyclodextrin was used in order to increase the stability of ciprofloxacin hydrochloride. In situ gels were prepared based on the concept of thermosensitive and pH induced in situ gelation. The inclusion complex of ciprofloxacin hydrochloride with hydroxypropyl-beta-cyclodextrin was prepared at a 1:1 molar ratio. The complex formation was thoroughly confirmed using various techniques, including (1)H NMR spectroscopy, FTIR spectrophotometry and differential scanning calorimetry. Both pure ciprofloxacin HCI and the inclusion complex were individually used in the formulations. Formulations were successfully prepared which were liquid at room temperature and exhibited viscosity increase and gelation at ophthalmic temperature. As a result of antimicrobial efficacy and in vitro release experiments, the developed formulations were found therapeutically efficient and provided sustained release of the drug over an 8 h period. These systems can be more advantageous than conventional eye drops.

  15. INJECTION CHOICE FOR SPALLATION NEUTRON SOURCE RING.

    SciTech Connect

    WEI,J.; BEEBE-WANG,J.; BLASKIEWICZ,M.; BRODOWSKI,J.; FEDOTOV,A.; GARDNER,C.; LEE,Y.Y.; RAPARIA,D.; DANILOV,V.; HOLMES,J.; PRIOR,C.; REES,G.; MACHIDA,S.

    2001-06-18

    Injection is key in the low-loss design of high-intensity proton facilities like the Spallation Neutron Source (SNS). During the design of both the accumulator and the rapid-cycling-synchrotron version of the SNS, extensive comparison has been made to select injection scenarios that satisfy SNS's low-loss design criteria. This paper presents issues and considerations pertaining to the final choice of the SNS injection systems.

  16. Characterization of slow-gelling alginate hydrogels for intervertebral disc tissue-engineering applications.

    PubMed

    Growney Kalaf, Emily A; Flores, Reynaldo; Bledsoe, J Gary; Sell, Scott A

    2016-06-01

    Reversal of intervertebral disc degeneration can have a potentially monumental effect on spinal health. As such, the goal of this research is to create an injectable, cellularized alginate-based nucleus pulposus that will restore disc function; with the primary goal of creating an alginate gel with tailorable rates of gelation to improve functionality over standard CaCl2 crosslinking techniques. Gelation characteristics of 1% sodium alginate were analyzed over various molar concentrations of a 1:2 ratio of CaCO3:glucono-δ-lactone (GDL), with 10% CaCl2 as the control crosslinker. Alginate construct characterization for all concentrations was performed via ultimate and cyclic compressive testing over a 28day degradation period in PBS. Dehydration, swell testing, and albumin release kinetics were determined, and cytotoxicity and cell homogeneity tests showed promise for cellularization strategies. Overall, the 30 and 60mM GDL alginate concentrations presented the most viable option for use in further studies, with a gelation time between 10 and 30min, low hysteresis over control, low percent change in thickness and weight under both PBS degradation and swelling conditions, and stable mechanical properties over 28days in vitro.

  17. In situ gelling stimuli-sensitive block copolymer hydrogels for drug delivery.

    PubMed

    He, Chaoliang; Kim, Sung Wan; Lee, Doo Sung

    2008-05-08

    Stimuli-sensitive block copolymer hydrogels, which are reversible polymer networks formed by physical interactions and exhibit a sol-gel phase-transition in response to external stimuli, have great potential in biomedical and pharmaceutical applications, especially in site-specific controlled drug-delivery systems. The drug may be mixed with a polymer solution in vitro and the drug-loaded hydrogel can form in situ after the in vivo administration, such as injection; therefore, stimuli-sensitive block copolymer hydrogels have many advantages, such as simple drug formulation and administration procedures, no organic solvent, site-specificity, a sustained drug release behavior, less systemic toxicity and ability to deliver both hydrophilic and hydrophobic drugs. Among the stimuli in the biomedical applications, temperature and pH are the most popular physical and chemical stimuli, respectively. The temperature- and/or pH-sensitive block copolymer hydrogels for biomedical applications have been extensively developed in the past decade. This review focuses on recent development of the preparation and application for drug delivery of the block copolymer hydrogels that respond to temperature, pH or both stimuli, including poly(N-substituted acrylamide)-based block copolymers, poloxamers and their derivatives, poly(ethylene glycol)-polyester block copolymers, polyelectrolyte-based block copolymers and the polyelectrolyte-modified thermo-sensitive block copolymers. In addition, the hydrogels based on other stimuli-sensitive block copolymers are discussed.

  18. Homicide by intravenous injection of naphtha.

    PubMed

    Case, M E; Poklis, A; Mackell, M A

    1985-01-01

    A case of homicide by the intravenous injection of Energine, a petroleum distillate spot remover, is presented. This case is the only known homicide committed with naphtha. This elderly man had severe natural disease in addition to chest trauma sustained in the assault leading to death; however, the rapid injection of approximately 25 mL of Energine was the overwhelming cause of death.

  19. Improving reservoir conformance using gelled polymer systems. Final report, September 25, 1992--July 31, 1996

    SciTech Connect

    Green, D.W.; Willhite, G.P.; Buller, C.; McCool, S.; Vossoughi, S.; Michnick, M.

    1997-06-01

    The objectives of the research program were to (1) identify and develop polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focused on four types of gel systems--KUSP1 systems that contain an aqueous polysaccharide designated KUSP1, phenolic-aldehyde systems composed of resorcinol and formaldehyde, colloidal-dispersion systems composed of polyacrylamide and aluminum citrate, and a chromium-based system where polyacrylamide is crosslinked by chromium(III). Gelation behavior of the resorcinol-formaldehyde systems and the KUSP1-borate system was examined. Size distributions of aggregates that form in the polyacrylamide-aluminum colloidal-dispersion gel system were determined. Permeabilities to brine of several rock materials were significantly reduced by gel treatments using the KUSP1 polymer-ester (monoethyl phthalate) system, the KUSP1 polymer-boric acid system, and the sulfomethylated resorcinol-formaldehyde system were also shown to significantly reduce the permeability to supercritical carbon dioxide. A mathematical model was developed to simulate the behavior of a chromium redox-polyacrylamide gel system that is injected through a wellbore into a multi-layer reservoir in which crossflow between layers is allowed. The model describes gelation kinetics and filtration of pre-gel aggregates in the reservoir. Studies using the model demonstrated the effect filtration of gel aggregates has on the placement of gel systems in layered reservoirs.

  20. Improving reservoir conformance using gelled polymer systems. Annual report, September 25, 1994--September 24, 1995

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1996-05-01

    The objectives of the research program are to (1) identify and develop polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focused on four types of gel systems -- KUSP1 systems which contain an aqueous polysaccharide designated KUSP1, phenolic-aldehyde systems composed of resorcinol and formaldehyde, colloidal-dispersion systems composed of polyacrylamide and aluminum citrate, and a chromium-based system where polyacrylamide is crosslinked by chromium(III). Gelation behavior of the resorcinol-formaldehyde systems and the KUSP1-borate system was examined. Size distributions of aggregates that form in the polyacrylamide-aluminum colloidal-dispersion gel system were determined. Permeabilities to brine of several rock materials were significantly reduced by gel treatments using the KUSP1 polymer-ester (monoethylphthalate) system, the KUSP1 polymer-boric acid system, and the sulfomethylated resorcinol-formaldehyde system. The KUSP1 polymer-ester system and the sulfomethylated resorcinol-formaldehyde system were also shown to significantly reduce the permeability to super-critical carbon dioxide. A mathematical model was developed to simulate the behavior of a chromium redox-polyacrylamide gel system that is injected through a wellbore into a multi-layer reservoir in which crossflow between layers is allowed. The model describes gelation kinetics and filtration of pre-gel aggregates in the reservoir. Studies using the model demonstrated the effect filtration of gel aggregates has on the placement of gel systems in layered reservoirs.

  1. Rapid determination of 30 bioactive constituents in XueBiJing injection using ultra high performance liquid chromatography-high resolution hybrid quadrupole-orbitrap mass spectrometry coupled with principal component analysis.

    PubMed

    Zuo, Lihua; Sun, Zhi; Hu, Yurong; Sun, Ya; Xue, Wenhua; Zhou, Lin; Zhang, Jun; Bao, Xiaoyue; Zhu, Zhenfeng; Suo, Guanglu; Zhang, Xiaojian

    2017-04-15

    Xuebijing injection (XBJ) is a traditional Chinese herbal prescription widely used in the treatment of sepsis. Extensive chemical studies revealed that XBJ injection contains amino acids, phenolic acids, flavonoid glycosides, terpeneglycosides and phthalides. In this study, the applicability of ultra high performance liquid chromatography coupled with high resolution hybrid quadruple-orbitrap mass spectrometry (UHPLC-Q-Orbitrap MS) for the simultaneous quantitative analysis of 30 bioactive constituents in XueBiJing injection (XBJ) was investigated. The mass spectrometer was operated in full MS scan mode. The use of 70,000FWHM mass resolution and narrow mass windows (5ppm) could effectively improve the selectivity of the method. Separation was achieved on a Waters ACQUITY UPLC(®) HSS C18 column (2.1mm×100mm, 1.8μm) with a gradient mobile phase consisting of acetonitrile-water (containing 10mM ammonium acetate) at a flow rate of 0.2mL/min. Satisfactory linearity was achieved within wide linear range and all correlation coefficients (r) of analytes were more than 0.9996. The limits of detection (LODs) were in the range of 0.1180-27.82ng/mL for different analytes. The relative standard deviations (RSDs) of inter- and intra-day precisions were less than 3.0% and the recoveries of the assay were in the range of 98.5%-101.5%. The validated method was successfully applied for simultaneous determination of 30 bioactive compounds in XueBiJing injection from 10 batches samples by UHPLC-Q-Orbitrap MS within 10min. Moreover, the results were evaluated principal component analysis and two compounds might be the most important chemical markers for chemical quality control of XBJ injection. The novel Q-Orbitrap mass spectrometry has been proved to be a very promising and powerful tool for routine screening of bioactive compounds in traditional Chinese medicine injection, ensuring drug safety and public health. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Intravenous injections in neonatal mice.

    PubMed

    Gombash Lampe, Sara E; Kaspar, Brian K; Foust, Kevin D

    2014-11-11

    Intravenous injection is a clinically applicable manner to deliver therapeutics. For adult rodents and larger animals, intravenous injections are technically feasible and routine. However, some mouse models can have early onset of disease with a rapid progression that makes administration of potential therapies difficult. The temporal (or facial) vein is just anterior to the ear bud in mice and is clearly visible for the first two days after birth on either side of the head using a dissecting microscope. During this window, the temporal vein can be injected with volumes up to 50 μl. The injection is safe and well tolerated by both the pups and the dams. A typical injection procedure is completed within 1-2 min, after which the pup is returned to the home cage. By the third postnatal day the vein is difficult to visualize and the injection procedure becomes technically unreliable. This technique has been used for delivery of adeno-associated virus (AAV) vectors, which in turn can provide almost body-wide, stable transgene expression for the life of the animal depending on the viral serotype chosen.

  3. Intravenous Injections in Neonatal Mice

    PubMed Central

    Gombash Lampe, Sara E.; Kaspar, Brian K.; Foust, Kevin D.

    2014-01-01

    Intravenous injection is a clinically applicable manner to deliver therapeutics. For adult rodents and larger animals, intravenous injections are technically feasible and routine. However, some mouse models can have early onset of disease with a rapid progression that makes administration of potential therapies difficult. The temporal (or facial) vein is just anterior to the ear bud in mice and is clearly visible for the first two days after birth on either side of the head using a dissecting microscope. During this window, the temporal vein can be injected with volumes up to 50 μl. The injection is safe and well tolerated by both the pups and the dams. A typical injection procedure is completed within 1-2 min, after which the pup is returned to the home cage. By the third postnatal day the vein is difficult to visualize and the injection procedure becomes technically unreliable. This technique has been used for delivery of adeno-associated virus (AAV) vectors, which in turn can provide almost body-wide, stable transgene expression for the life of the animal depending on the viral serotype chosen. PMID:25407048

  4. Preparation of demipermanent and semipermanent hair dyes gels from ethanol extract of Caesalpinia sappan L. using carbomer as gelling agent

    NASA Astrophysics Data System (ADS)

    Indrawati, T.; Syahrin, A.; Irpan

    2017-07-01

    Caesalpinia sappan L. (Cs L) contains of essential oils, saponin, brazilin, brazilein, alkaloids, flavonoids and tannins that have a function as cationic natural dyes. The aim of this research was to prepare the ethanol extract of Cs L wood and to prepare demi-permanent and semi-permanent of hair dye gels by using Carbomer of 2 % and 1.5 % as gelling agent and Cs L extract as cationic dyes. The Extract of Cs L was macerated by using ethanol of 96 % as the solvent, and then thickened. Three formula of demi-permanent hair dye gels were made by using Cs L extract of 3 %, 6% and 9 %. Three formula of semi-permanent hair dye gels were made by using Cs L extract of 2.50 %, 7.00 % and 10.50 %. Those hair dyes gels were prepared by swelling and mixing methods. All products of hair dyes gels were evaluated with organoleptic test, homogeneity test, pH test, consistency test, rheological properties test and dyeing effect test. The demi-permanent hair dye gels products had brown to brown dark black colors, pH of 5.05-5.43, homogeny, specific Cs L odor, and had pseudoplastic thixotropic flow characteristic. The semi-permanent hair dye gels products had red color pH of 6.5-6.25, homogeny, Cs L odor, and have pseudoplastic thixotropic flow characteristics. The optimum formula of demi-permanent was formula gel that contained of 6 % extract of Cs L and the optimum formula of permanent hair dyes gel was formula that contained of 10.50 % extract of Cs L.

  5. Intranasal delivery of Norwalk virus-like particles formulated in an in-situ gelling, dry powder vaccine

    PubMed Central

    Velasquez, Lissette S.; Shira, Samantha; Berta, Alice N.; Kilbourne, Jacquelyn; Medi, Babu M.; Tizard, Ian; Ni, Yawei; Arntzen, Charles J.; Herbst-Kralovetz, Melissa M.

    2011-01-01

    The development of a vaccine to prevent norovirus infections has been focused on immunization at a mucosal surface, but has been limited by the low immunogenicity of self-assembling Norwalk virus-like particles (NV VLPs) delivered enterically or at nasal surfaces. Nasal immunization, which offers the advantage of ease of immunization, faces obstacles imposed by the normal process of mucociliary clearance, which limits residence time of applied antigens. Herein, we describe the use of a dry powder formulation (GelVac) of an inert in-situ gelling polysaccharide (GelSite) extracted from Aloe vera for nasal delivery of NV VLP antigen. Powder formulations, with or without NV VLP antigen, were similar in structure in dry form or when rehydrated in simulated nasal fluids. Immunogenicity of the dry powder VLP formulation was compared to equivalent antigen/adjuvant liquid formulations in animals. For the GelVac powder, we observed superior NV-specific serum and mucosal (aerodigestive and reproductive tracts) antibody responses relative to liquid formulations. Incorporation of TLR7 agonist gardiquimod in dry powder formulations did not enhance antibody responses, although its inclusion in liquid formulations did enhance VLP immunogenicity irrespective of the presence or absence of GelSite. We interpret these data as showing that GelSite-based dry powder formulations 1.) stabilize the immunogenic structural properties of VLPs and 2.) induce systemic and mucosal antibody titers which are equal or greater than those achieved by VLPs plus adjuvant in a liquid formulation. We conclude that in-situ gelation of the GelVac dry powder formulation at nasal mucosal surfaces delays mucociliary clearance and thereby prolongs VLP antigen exposure to immune effector sites. PMID:21640778

  6. Darbepoetin Alfa Injection

    MedlinePlus

    ... to inject it.Darbepoetin alfa injection comes in prefilled syringes and in vials to be used with disposable ... solution before injecting it. Be sure that the prefilled syringe or vial is labeled with the correct name ...

  7. Epidural Injections for Spinal Pain

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z Epidural Injections An epidural injection provides temporary or prolonged relief ... limitations of Epidural Injection? What is an Epidural Injection? An epidural injection is an injection of medication ...

  8. Beam Injection into RHIC

    NASA Astrophysics Data System (ADS)

    Fischer, W.; Hahn, H.; Mackay, W. W.; Tsoupas, N.

    1997-05-01

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. We describe the injection zone and its bottlenecks, the application program to steer the beam and the injection kickers. We report on the commissioning of the injection systems and on measurements of the kickers.

  9. Aqueous two-phase system cold-set gelation using natural and recombinant probiotic lactic acid bacteria as a gelling agent.

    PubMed

    Léonard, Lucie; Husson, Florence; Langella, Philippe; Châtel, Jean-Marc; Saurel, Rémi

    2016-05-01

    The present study aimed to entrap probiotic lactic acid bacteria (LAB) in a sodium alginate and sodium caseinate aqueous two-phase gel system. The natural acidifying properties of two therapeutic probiotic LAB were exploited to liberate calcium ions progressively from calcium carbonate (CaCO3), which caused the gelation of the co-existing phases. Bi-biopolymeric matrix gelation of GDL/CaCO3 or LAB/CaCO3 was monitored by dynamic rheological measurements, and the final gels were characterized by frequency dependence measurements and confocal laser scanning microscopy. Weak to strong gels were formed with an elastic modulus G' from 10 to 1.000Pa, respectively. After cold-set gelation of our system, confocal laser scanning microscopy showed spherical protein microdomains trapped within a calcium alginate network. LAB cells were stained to study their partition in the self-gelling matrices. Our LAB strains showed two different behaviors, which may relate to the exopolysaccharide production: (i) Lactobacillus plantarum CNRZ1997 cells were found mainly in continuous alginate networks, whereas (ii) Lactococcus lactis cells were localized in protein microdomains. This alginate-caseinate phase-separated system that was self-gelled by LAB cells may be an innovative approach for immobilizing and protecting LAB cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Comparison of ion-activated in situ gelling systems for ocular drug delivery. Part 1: physicochemical characterisation and in vitro release.

    PubMed

    Rupenthal, Ilva D; Green, Colin R; Alany, Raid G

    2011-06-15

    Conventional eye drops can result in poor drug bioavailability due to the unique ocular anatomy and physiology. Ion-activated in situ gelling systems are able to crosslink with cations present in the tear fluid, therefore forming a gel on the ocular surface, which results in prolonged corneal contact time. The present study compared a number of anionic polysaccharides (gellan gum, xanthan gum, carrageenan and alginate) to an uncharged (HPMC) and a positively charged (chitosan) polymer system with emphasis on the gelling behaviour, rheological and textural properties, gel microstructure, contact angle and in vitro release characteristics. All systems exhibited physically entangled polymer networks that were able to disentangle upon shear stress and significantly prolonged the in vitro release of a model hydrophilic drug compared to a solution. While systems based on HPMC and chitosan showed no structural changes upon addition of cations, formulations based on gellan gum and carrageenan demonstrated a remarkable increase in viscosity, pseudoplasticity and hardness upon addition of Ca(2+) and K(+) respectively. This renders them favourable for ocular use as they would gel once in contact with the cations of the tear fluid, thus reducing nasolacrimal drainage, but would thin upon shearing, preventing ocular irritation and therefore induced lacrimation.

  11. Oil-in-water emulsion gels stabilized with chia (Salvia hispanica L.) and cold gelling agents: Technological and infrared spectroscopic characterization.

    PubMed

    Pintado, T; Ruiz-Capillas, C; Jiménez-Colmenero, F; Carmona, P; Herrero, A M

    2015-10-15

    This paper reports on the development of olive oil-in-water emulsion gels containing chia (Salvia hispanica L.) (flour or seed) and cold gelling agents (transglutaminase, alginate or gelatin). The technological and structural characteristics of these emulsion gels were evaluated. Both structural and technological changes in emulsion gels resulting from chilled storage were also determined. The color and texture of emulsion gels depend on both the cold gelling agents used and chilled storage. Lipid oxidation increased (p < 0.05) during storage in emulsion gels containing transglutaminase or alginate. Analyses of the half-bandwidth of the 2923 cm(-1) band and the area of the 3220 cm(-1) band suggest that the order/disorder of the oil lipid chain related to lipid interactions and droplet size in the emulsion gels could be decisive in determining their textural properties. The half-bandwidth of 2923 cm(-1) band and area of 3220 cm(-1) band did not show significant differences during chilled storage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. [Preparation and pharmacokinetic evaluation of long-acting injectable oily suspensions for ophiopogonis radix polysaccharide MDG-1].

    PubMed

    Shi, Xiao-Li; Yao, Chun-Xia; Lin, Xiao; Shen, Lan; Feng, Yi

    2014-07-01

    To evaluate in vivo pharmacokinetics of Ophiopogonis Radix polysaccharide MDG-1 oily suspension injection prepared with different prescriptions in rats, and explore the feasibility of the long-acting drug delivery of MDG-1 Injection by using the oily suspension drug release system. MDG-1 microparticles were prepared by the anti-solvent precipitation method. Their size and size distribution were characterized. Castor oil with a high viscosity or aluminum stearate were added into soybean oil with a low viscosity, in order to prepare oily media with different viscosities, detect their rheological properties and screen out superior prescriptions for in vivo evaluation. The average size of microparticles was 21.81 microm, and the span between them was 2.63. The in vivo evaluation was conducted for prescriptions of mixed oil (soybean oil/castor oil, 2: 3) and soybean oils gelled by 2% and 4% aluminium stearate. Among them, the prescription of soybean gelled by 4% aluminium stearate could significantly reduce C(max) and prolong the apparent t1/2, with the MDG-1 release time of several days. It is feasible to achieve the long-acting MDG-1 drug delivery by using oily media with a high viscosity.

  13. Metallized gelled monopropellants

    NASA Technical Reports Server (NTRS)

    Nieder, Erin G.; Harrod, Charles E.; Rodgers, Frederick C.; Rapp, Douglas C.; Palaszewski, Bryan A.

    1992-01-01

    Thermochemical calculations of seven metallized monopropellants were conducted to quantify theoretical specific impulse and density specific impulse performance. On the basis of theoretical performance, commercial availability of formulation constituents, and anticipated viscometric behavior, two metallized monopropellants were selected for formulation characterization: triethylene glycol dinitrate, ammonium perchlorate, aluminum and hydrogen peroxide, aluminum. Formulation goals were established, and monopropellant formulation compatibility and hazard sensitivity were experimentally determined. These experimental results indicate that the friction sensitivity, detonation susceptibility, and material handling difficulties of the elevated monopropellant formulations and their constituents pose formidable barriers to their future application as metallized monopropellants.

  14. Modulating rheological and degradation properties of temperature-responsive gelling systems composed of blends of PCLA-PEG-PCLA triblock copolymers and their fully hexanoyl-capped derivatives.

    PubMed

    Petit, Audrey; Müller, Benno; Bruin, Peter; Meyboom, Ronald; Piest, Martin; Kroon-Batenburg, Loes M J; de Leede, Leo G J; Hennink, Wim E; Vermonden, Tina

    2012-12-01

    In this study, the ability to modulate rheological and degradation properties of temperature-responsive gelling systems composed of aqueous blends of poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) (PCLA-PEG-PCLA) triblock copolymers (i.e. uncapped) and their fully capped derivatives was investigated. Uncapped and capped PCLA-PEG-PCLA triblock copolymers, abbreviated as degree of modification 0 and 2 (DM0 and DM2, respectively), were composed of identical PCLA and PEG blocks but different end groups: namely hydroxyl and hexanoyl end groups. DM0 was synthesized by ring opening polymerization of l-lactide and ε-caprolactone in toluene using PEG as initiator and tin(II) 2-ethylhexanoate as the catalyst. A portion of DM0 was subsequently reacted with an excess of hexanoyl chloride in solution to yield DM2. The cloud point and phase behaviour of DM0 and DM2 in buffer as well as that of their blends were determined by light scattering in a diluted state and by vial tilting and rheological measurements in a concentrated state. Degradation/dissolution properties of temperature-responsive gelling systems were studied in vitro at pH 7.4 and 37°C. The cloud points of DM0/DM2 blends were ratio-dependent and could be tailored from 15 to 40°C for blends containing 15 to 100wt.% DM0. Vial tilting and rheological experiments showed that, with solid contents between 20 and 30wt.%, DM0/DM2 blends (15/85 to 25/75w/w) had a sol-to-gel transition temperature at 10-20°C, whereas blends with less than 15wt.% DM0 formed gels below 4°C and the ones with more than 25wt.% DM0 did not show a sol-to-gel transition up to 50°C. Complete degradation of temperature-responsive gelling systems took ∼100days, independent of the DM0 fraction and the initial solid content. Analysis of residual gels in time by GPC and (1)H-NMR showed no chemical polymer degradation, but indicated gel degradation by dissolution. Preferential dissolution of lactoyl

  15. Injection practices in southern part of India.

    PubMed

    Rajasekaran, M; Sivagnanam, G; Thirumalaikolundusubramainan, P; Namasivayam, K; Ravindranath, C

    2003-05-01

    The World Health Organization defines 'a safe injection' as one that does not harm the recipient, does not expose the provider to any avoidable risk, and does not result in any waste that is dangerous to the community. Irrational and unsafe injection practices are rife in developing countries. The objective of the present study was to assess the injection practices in the state of Tamilnadu, India, using the Rapid assessment and response guide of the Safe Injection Global Network of the World Health Organization. Thirty-nine prescribers, 62 providers, and 175 members of the general public were interviewed. The areas were chosen out of convenience while at the same time adhering to the guidelines. The study was carried out between April and June 2001. The per capita injection rate was 2.4 per year. The ratio of therapeutic to immunization injections was 6.5:1, and the proportion of injections given with a disposable syringe and needle was 35.4%. Knowledge about diseases transmitted by unsafe injections, for example involving human immunodeficiency virus and hepatitis B virus, was greater among all the study groups. The annual incidence of needlestick injuries among providers was 23.6, which is extremely high. It is concluded that there are deficiencies in practice such as an excessive, unwarranted usage of injections, a sizeable prevalence of unsafe injection practices, the short supply of injection equipment leading to a high incidence of needlestick injuries, a low proportion of hepatitis B virus immunization among providers, and a lack of adequate sharps containers and disposal facilities in this part of India. It is suggested that immediate and long-term remedial measures, such as the education of prescribers to reduce the number of injections to a bare minimum, an adequate supply of injection equipment, provider protection with immunization for hepatitis B virus, the provision of adequate sharps containers with safe disposal facilities and, not least, community

  16. In situ gelling pH- and temperature-sensitive biodegradable block copolymer hydrogels for drug delivery.

    PubMed

    Singh, Narendra K; Lee, Doo Sung

    2014-11-10

    Stimuli-sensitive injectable polymeric hydrogels have been extensively investigated during the past decade as bioactive agent delivery vehicles and for tissue engineering applications. An aqueous solution of these polymers undergoes a sol-to-gel phase transition in response to external stimuli such as pH, temperature, salt, light, biomolecules, electromagnetic field, etc. Bioactive molecules or cells can be mixed into the low-viscosity state of the polymer solution and injected into the body at a target site, forming an in situ hydrogel depot, which can then serve as bioactive-molecule-releasing carriers or a cell-growing microenvironment. This review systematically summarizes the recent progress in biodegradable and injectable block copolymer hydrogels, giving special attention to the novel and promising pH- and temperature-sensitive injectable block copolymer hydrogels for biomedical applications. The gelation mechanism, formation of ionic complexes, and biodegradation are highlighted as key factors responsible for controlled protein/drug delivery. The advantages and perspectives of pH- and temperature-sensitive injectable block copolymer hydrogels are also highlighted.

  17. Antigen injection (image)

    MedlinePlus

    Leprosy is caused by the organism Mycobacterium leprae . The leprosy test involves injection of an antigen just under ... if your body has a current or recent leprosy infection. The injection site is labeled and examined ...

  18. Amphotericin B Liposomal Injection

    MedlinePlus

    Amphotericin B liposomal injection is used to treat fungal infections such as cryptococcal meningitis (a fungal infection of the ... infections in people who cannot receive conventional amphotericin B therapy. Amphotericin B liposomal injection is in a ...

  19. Calcitonin Salmon Injection

    MedlinePlus

    Calcitonin salmon injection is used to treat osteoporosis in postmenopausal women. Osteoporosis is a disease that causes bones to weaken and break more easily. Calcitonin salmon injection is also used to treat Paget's disease ...

  20. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  1. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  2. Collagenase Clostridium Histolyticum Injection

    MedlinePlus

    Collagenase Clostridium histolyticum injection is used to treat Dupuytren's contracture (a painless thickening and tightening of tissue [cord] beneath ... of tissue can be felt upon examination. Collagenase Clostridium histolyticum injection is also used to treat Peyronie's ...

  3. Brentuximab Vedotin Injection

    MedlinePlus

    ... healthy bone marrow) or at least two treatment periods of chemotherapy. Brentuximab vedotin injection is also used ... lymphoma) who did not respond to another treatment period of chemotherapy. Brentuximab vedotin injection is in a ...

  4. Sodium Ferric Gluconate Injection

    MedlinePlus

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  5. OnabotulinumtoxinA Injection

    MedlinePlus

    Botox® Cosmetic ... OnabotulinumtoxinA injection (Botox, Botox Cosmetic) is used to treat a number of conditions.OnabotulinumtoxinA injection (Botox) is used to relieve the symptoms of cervical dystonia ( ...

  6. Slit injection device

    DOEpatents

    Alger, Terry W.; Schlitt, Leland G.; Bradley, Laird P.

    1976-06-15

    A laser cavity electron beam injection device provided with a single elongated slit window for passing a suitably shaped electron beam and means for varying the current density of the injected electron beam.

  7. Urinary incontinence - injectable implant

    MedlinePlus

    Intrinsic sphincter deficiency repair; ISD repair; Injectable bulking agents for stress urinary incontinence ... Urine leakage that gets worse Pain where the injection was done Allergic reaction to the material Implant ...

  8. Hip joint injection

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

  9. Rich catalytic injection

    SciTech Connect

    Veninger, Albert

    2008-12-30

    A gas turbine engine includes a compressor, a rich catalytic injector, a combustor, and a turbine. The rich catalytic injector includes a rich catalytic device, a mixing zone, and an injection assembly. The injection assembly provides an interface between the mixing zone and the combustor. The injection assembly can inject diffusion fuel into the combustor, provides flame aerodynamic stabilization in the combustor, and may include an ignition device.

  10. Beam injection into RHIC

    SciTech Connect

    Fischer, W.; Hahn, H.; MacKay, W.W.; Satogata, T.; Tsoupas, N.; Zhang, W.

    1997-07-01

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.

  11. RAPID REMOVAL OF A GROUNDWATER CONTAMINANT PLUME.

    USGS Publications Warehouse

    Lefkoff, L. Jeff; Gorelick, Steven M.; ,

    1985-01-01

    A groundwater management model is used to design an aquifer restoration system that removes a contaminant plume from a hypothetical aquifer in four years. The design model utilizes groundwater flow simulation and mathematical optimization. Optimal pumping and injection strategies achieve rapid restoration for a minimum total pumping cost. Rapid restoration is accomplished by maintaining specified groundwater velocities around the plume perimeter towards a group of pumping wells located near the plume center. The model does not account for hydrodynamic dispersion. Results show that pumping costs are particularly sensitive to injection capacity. An 8 percent decrease in the maximum allowable injection rate may lead to a 29 percent increase in total pumping costs.

  12. Novel injectable neutral solutions of chitosan form biodegradable gels in situ.

    PubMed

    Chenite, A; Chaput, C; Wang, D; Combes, C; Buschmann, M D; Hoemann, C D; Leroux, J C; Atkinson, B L; Binette, F; Selmani, A

    2000-11-01

    A novel approach to provide, thermally sensitive neutral solutions based on chitosan/polyol salt combinations is described. These formulations possess a physiological pH and can be held liquid below room temperature for encapsulating living cells and therapeutic proteins; they form monolithic gels at body temperature. When injected in vivo the liquid formulations turn into gel implants in situ. This system was used successfully to deliver biologically active growth factors in vivo as well as an encapsulating matrix for living chondrocytes for tissue engineering applications. This study reports for the first time the use of polymer/polyol salt aqueous solutions as gelling systems, suggesting the discovery of a prototype for a new family of thermosetting gels highly compatible with biological compounds.

  13. Strategies for safe injections.

    PubMed Central

    Battersby, A.; Feilden, R.; Stoeckel, P.; Da Silva, A.; Nelson, C.; Bass, A.

    1999-01-01

    In 1998, faced with growing international concern, WHO set out an approach for achieving injection safety that encompassed all elements from patients' expectations and doctors' prescribing habits to waste disposal. This article follows that lead and describes the implications of the approach for two injection technologies: sterilizable and disposable. It argues that focusing on any single technology diverts attention from the more fundamental need for health services to develop their own comprehensive strategies for safe injections. National health authorities will only be able to ensure that injections are administered safely if they take an approach that encompasses the whole system, and choose injection technologies that fit their circumstances. PMID:10680247

  14. Technical note: PaGELL v.1.5: A flexible parametric program for the Bayesian analysis of longevity data within the context of animal breeding.

    PubMed

    Casellas, J; Brito, L C

    2017-10-01

    This technical note presents the program PaGELL v.1.5 (Parametric Genetic Evaluation of Lifespan in Livestock), a flexible software program to analyze (right-censored) longevity data in livestock populations, with a special emphasis on the genetic evaluation of the breeding stock. This software relies on a parametric generalization of the proportional hazard model; more specifically, the baseline hazard function follows a Weibull process and flexibility is gained by including an additional time-dependent effect with the number of change points defined by the user. The program can accommodate 3 different sources of variation (i.e., systematic, permanent environmental, and additive genetic effects) and both fixed and time-dependent patterns (only for systematic and permanent environmental effects). Analyses are performed within a Bayesian context by sampling from the joint posterior distribution of the model, and model fit can be easily determined by the calculation of the deviance information criterion. Although this software has already been used on field data sets, its performance has been double-checked on simulated data set, and results are presented in this technical note. PaGELL v.1.5 was written in Fortran 95 language and, after compiling with the GNU Fortran Compiler v.4.7 and later, it has been tested in Windows, Linux, and MacOS operating systems (both 32- and 64-bit platforms). This program is available at http://www.casellas.info/files/pageII.zip. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Fuel injection apparatus

    SciTech Connect

    Omori, T.; Sakakibara, S.; Kato, M.; Masuda, A.

    1986-06-10

    A fuel injection apparatus is described for supplying fuel from a fuel tank to at least one combustion chamber of an internal combustion engine, comprising: an injector housing defining therein a pressure cylinder bore, an injection cylinder bore and a timing cylinder bore connected in series with the pressure cylinder bore; a pressure plunger, fitted in the pressure cylinder bore and having one end defining, in the pressure cylinder bore, a pressure pump chamber communicating with the injection cylinder bore and the timing cylinder bore; first fuel supply means for supplying fuel from the fuel tank to the pressure pump chamber; pressurizing means for reciprocating the pressure plunger in the pressure cylinder bore in synchronism with the engine operation so as to pressurize fuel in the pressure pump chamber; an injection plunger, having a diameter smaller than the pressure plunger, fitted in the injection cylinder bore and having two ends defining, in the injection cylinder bore, an injection pump chamber and a first communicating chamber communicating with the pressure pump chamber; second fuel supply means for adjusting the quantity of the fuel from the fuel tank in accordance with engine operation conditions so as to supply the adjusted fuel quantity to the injection pump chamber; injection valve means for injecting the fuel into the fuel pump chamber toward a combustion chamber of the engine when the pressure in the pressure pump chamber is applied to the injection plunger through the first communicating chamber, and the fuel pressure in the injection pump chamber reaches a predetermined injection pressure.

  16. Rapid Prototyping

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  17. [Stability of liensinine injection].

    PubMed

    Hu, X M; Zhou, B H; Luo, S D

    1993-06-01

    The stability of liensinine injection was studied by accelarating test with classical isothermal method. Results of the study showed that the decomposition of the injection was found to be a first-order reaction. The activation energy was 75030 J.mol-1. The shelf life at 10 degrees C and 25 degrees C was predicted to be about 15 months and 3 months respectively. This experiment provides a reference for the storage of the injection.

  18. Injection-water quality

    SciTech Connect

    Patton, C.C. )

    1990-10-01

    Ideally, injection water should enter the reservoir free of suspended solids or oil. It should also be compatible with the reservoir rock and fluids and would be sterile and nonscaling. This paper discusses how the objective of any water-injection operation is to inject water into the reservoir rock without plugging or permeability reduction from particulates, dispersed oil, scale formation, bacterial growth, or clay swelling. In addition, souring of sweet reservoirs by sulfate-reducing bacteria should be prevented if possible.

  19. Underground Injection Control (UIC)

    EPA Pesticide Factsheets

    Provide information on: individual injection well classes; regulations specific to each well class; technical guidance; compliance assistance; federal, state, and tribal/territory roles and responsibilities.

  20. Lumbar retrodiscal transforaminal injection.

    PubMed

    Jasper, Joseph F

    2007-05-01

    Spinal injections are commonly used to treat lumbar radiculitis and back pain. Delivery of medication to specific targeted pathology is considered important for a successful therapeutic outcome. A variety of routes of injection have been devised for epidural injection of corticosteroid. The author demonstrates a variation of the transforaminal injection technique. The radiographic spread of contrast is described using a more oblique and ventral caudad approach in the epidural space "retrodiscal." It is suggested that the radiographic findings of this technique for discogenic causes of induced radiculitis and/or back pain may yield more precise targeting of putative pathologic sources of radiculopathy and back pain in selected patients. In patients with disc pathology and radiculitis, the anatomy of the lumbar epidural space is reviewed for its potential effect on the flow of injectate. Contrast spread was documented for lumbar transforaminal injection using a needle placement more oblique and behind the disc rather than in the cranial portion. Comparison is made to a typical contrast spread of an infra-pedicular placed transforaminal injection. Retrodiscal contrast injection results in reliable coverage of the retrodiscal region, the exiting nerve at that foraminal level and the proximal portion of the transiting segmental neural sleeve. The radiographic findings demonstrate a difference between classic infra-pedicular versus retrodiscal transforaminal epidural contrast injection patterns, particularly at relatively low volumes. The clinical advantage of one technique versus the other should be established in randomized prospective studies.