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1

A comparative evaluation of the effect of internet-based CME delivery format on satisfaction, knowledge and confidence  

PubMed Central

Background Internet-based instruction in continuing medical education (CME) has been associated with favorable outcomes. However, more direct comparative studies of different Internet-based interventions, instructional methods, presentation formats, and approaches to implementation are needed. The purpose of this study was to conduct a comparative evaluation of two Internet-based CME delivery formats and the effect on satisfaction, knowledge and confidence outcomes. Methods Evaluative outcomes of two differing formats of an Internet-based CME course with identical subject matter were compared. A Scheduled Group Learning format involved case-based asynchronous discussions with peers and a facilitator over a scheduled 3-week delivery period. An eCME On Demand format did not include facilitated discussion and was not based on a schedule; participants could start and finish at any time. A retrospective, pre-post evaluation study design comparing identical satisfaction, knowledge and confidence outcome measures was conducted. Results Participants in the Scheduled Group Learning format reported significantly higher mean satisfaction ratings in some areas, performed significantly higher on a post-knowledge assessment and reported significantly higher post-confidence scores than participants in the eCME On Demand format that was not scheduled and did not include facilitated discussion activity. Conclusions The findings support the instructional benefits of a scheduled delivery format and facilitated asynchronous discussion in Internet-based CME.

2010-01-01

2

CME Theory and Models  

NASA Astrophysics Data System (ADS)

This chapter provides an overview of current efforts in the theory and modeling of CMEs. Five key areas are discussed: (1) CME initiation; (2) CME evolution and propagation; (3) the structure of interplanetary CMEs derived from flux rope modeling; (4) CME shock formation in the inner corona; and (5) particle acceleration and transport at CME driven shocks. In the section on CME initiation three contemporary models are highlighted. Two of these focus on how energy stored in the coronal magnetic field can be released violently to drive CMEs. The third model assumes that CMEs can be directly driven by currents from below the photosphere. CMEs evolve considerably as they expand from the magnetically dominated lower corona into the advectively dominated solar wind. The section on evolution and propagation presents two approaches to the problem. One is primarily analytical and focuses on the key physical processes involved. The other is primarily numerical and illustrates the complexity of possible interactions between the CME and the ambient medium. The section on flux rope fitting reviews the accuracy and reliability of various methods. The section on shock formation considers the effect of the rapid decrease in the magnetic field and plasma density with height. Finally, in the section on particle acceleration and transport, some recent developments in the theory of diffusive particle acceleration at CME shocks are discussed. These include efforts to combine self-consistently the process of particle acceleration in the vicinity of the shock with the subsequent escape and transport of particles to distant regions.

Forbes, T. G.; Linker, J. A.; Chen, J.; Cid, C.; Kóta, J.; Lee, M. A.; Mann, G.; Miki?, Z.; Potgieter, M. S.; Schmidt, J. M.; Siscoe, G. L.; Vainio, R.; Antiochos, S. K.; Riley, P.

2006-03-01

3

CME Theory and Models  

NASA Astrophysics Data System (ADS)

This chapter provides an overview of current efforts in the theory and modeling of CMEs. Five key areas are discussed: (1) CME initiation; (2) CME evolution and propagation; (3) the structure of interplanetary CMEs derived from flux rope modeling; (4) CME shock formation in the inner corona; and (5) particle acceleration and transport at CME driven shocks. In the section on CME initiation three contemporary models are highlighted. Two of these focus on how energy stored in the coronal magnetic field can be released violently to drive CMEs. The third model assumes that CMEs can be directly driven by currents from below the photosphere. CMEs evolve considerably as they expand from the magnetically dominated lower corona into the advectively dominated solar wind. The section on evolution and propagation presents two approaches to the problem. One is primarily analytical and focuses on the key physical processes involved. The other is primarily numerical and illustrates the complexity of possible interactions between the CME and the ambient medium. The section on flux rope fitting reviews the accuracy and reliability of various methods. The section on shock formation considers the effect of the rapid decrease in the magnetic field and plasma density with height. Finally, in the section on particle acceleration and transport, some recent developments in the theory of diffusive particle acceleration at CME shocks are discussed. These include efforts to combine self-consistently the process of particle acceleration in the vicinity of the shock with the subsequent escape and transport of particles to distant regions.

Forbes, T. G.; Linker, J. A.; Chen, J.; Cid, C.; Kóta, J.; Lee, M. A.; Mann, G.; Miki?, Z.; Potgieter, M. S.; Schmidt, J. M.; Siscoe, G. L.; Vainio, R.; Antiochos, S. K.; Riley, P.

4

CME stimulated by eruptive prominence  

NASA Astrophysics Data System (ADS)

A model of CME arising due to drift motion in the corona in the presence of an eruptive prominence is presented. Magnetic field configuration is in accordance with a model of inverse polarity. In a region where a magnetic pressure of the filament magnetic field is greater than a gas pressure, plasma motion can be assumed as a drift motion. Its characteristic is such that the further one gets from the filament, the higher is drift velocity of a plasma. That sort of motion leads to a rarefaction of plasma and formation of a cavity around the filament. But a current strength in eruptive prominences estimated from observations is such that the region b is less than 1 has a limited size. Near the boundary b = 1 plasma deceleration is occurred and as a result of it coronal density is increasing. Plasma condensation near the surface b = 1 leads to formation of a dense envelope which can be collated with an outer loop of CME. Two dimensional numerical MHD simulation displays a process of cavity and loop formation. If a current is large enough, two compact regions of compressed dense matter arise at both sides of the rising filament and two narrow jets are developed. This scenario, perhaps, corresponds to CMEs in which a top of the loop is faint or it is absent at all.

Filippov, B. P.

1995-06-01

5

CME Speed Activity  

NSDL National Science Digital Library

In this activity students use pictures of Coronal Mass Ejection (CME) activity near the Sun, taken by the National Aeronautics and Space Administration/European Space Agency (NASA/ESA) Solar Heliospheric Observatory (SOHO) satellite, and calculate the speed of a CME. They discover that Coronal Mass Ejections are major storms on the Sun, which can hurl billions of tons of matter into space in a matter of a few hours. Traveling at millions of kilometers per hour, some of these clouds occasionally collide with the Earth and have produced power blackouts and satellite damage. Students view pictures in which they can see material being ejected from the Sun. They are given the elapsed time between frames, and the diameter of the sun, and are asked to select a feature in the expanding gas CME and measure its distance from the Sun from one frame to the next in order to calculate the speed of that feature. Students then plot the information and answer some questions about the speed of the CME.

Higley, Susan

6

Formation of hot channels in pre-CME coronal flux ropes and their role in the onset of eruptions  

NASA Astrophysics Data System (ADS)

Using 3D magneto-hydrodynamic simulations of the eruption of coronal flux ropes, we examine the thermal features produced by current sheet formation and the associated “tether-cutting” reconnections. We find that current sheets form along topological structures identified as quasi-separatrix layers (QSLs) during the pre-eruption stage. Tether-cutting reconnections in the current sheets produce a hot channel containing reconnected, twisted flux threading under the axis of the flux rope. This accumulation of twisted flux allows the flux rope to rise quasi-statically to the critical height for the onset of the torus instability, which leads to the dynamic eruption of the flux rope. The current sheet morphology and the hot channel that forms above it may explain the observed prominence “horns” enclosing a central cavity seen in AIA observations of coronal cavities. They may also be the cause of the X-ray emitting cores observed in some coronal cavities. We present a sequence of simulations to examine how the temperature and density of the hot channel depend on the properties of the coronal flux rope, and compare the results with multi-wavelength coronal observations of CMEs.

Fan, Yuhong; Chatterjee, P.

2013-07-01

7

CME on CME Interaction on January 17, 2005  

NASA Astrophysics Data System (ADS)

On January 17, 2005 a complex radio event associated with an X3.8 SXR flare and two fast Halo CMEs (CME1 & CME2 henceforward) in close succession was observed. We present combined ARTEMIS-IV & WIND WAVES dynamic spectra which provide a complete view of the radio emission induced by shock waves and electron beams from the low corona to about 1 A.U. These are supplemented with data, from the Nançay Radioheliograph (NRH), GOES, EIT and LASCO for the study of the associated flare and CME activity.

Bouratzis, C.; Preka-Papadima, P.; Moussas, X.; Hillaris, A. E.; Caroubalos, C.; Alissandrakis, C. E.; Tsitsipis, P.; Kontogeorgos, A.

2010-07-01

8

CME-CME interaction during the 2010 August 1 events  

NASA Astrophysics Data System (ADS)

We study a CME-CME interaction that occurred during the 2010 August 1 events using STEREO/SECCHI data (COR and HI). The CMEs were Earth directed where clear signatures of magnetic flux ropes could be measured from in situ Wind data. To give evidence of the actual interaction we derive the direction of motion for both CMEs applying several independent methods. From this we obtain that both CMEs head into similar directions enabling us to actually observe the merging in the HI1 field-of-view (and rule out the possibility that this is just a line of sight effect). The full de-projected kinematics of the faster CME from Sun to Earth is derived when combining data points from remote observations with in situ parameters of the ICME measured at 1 AU. We study the evolution of the kinematical profile of the faster CME by applying a drag based model.

Temmer, M.; Vrsnak, B.; Rollett, T.; Bein, B.; deKoning, C. A.; Liu, Y.; Bosman, E.; Davies, J. A.; Möstl, C.; Zic, T.; Veronig, A. M.; Bothmer, V.; Harrison, R.; Nitta, N.; Bisi, M.; Flor, O.; Eastwood, J.; Odstrcil, D.; Forsyth, R.

2012-04-01

9

The fastest CME of Cycle 23 overtakes another fast CME  

NSDL National Science Digital Library

On November 4, 2003, the Sun produced its fastest coronal mass ejection (CME) for cycle 23 out of the active region 0486 located near the southwest limb of the Sun. The CME was expelled with a speed of approximately 2700 km-s. At the time of the launch of this CME, there was another ejection in progress from the same region. The previous ejection started about 7 hours earlier with a speed of about 1000 km-s. The fastest CME overtook the previous one within 2 hours and produced a spectacular radio radiation detected by the Wind, Ulysses and Cassini spacecraft. The movie shows the radio emission and the two interacting CMEs as observed by the SOHO spacecraft.

Bridgman, Tom; Gopalswamy, Natchimuthuk

2004-05-23

10

Multi-protein Delivery by Nanodiamonds Promotes Bone Formation.  

PubMed

Bone morphogenetic proteins (BMPs) are well-studied regulators of cartilage and bone development that have been Food and Drug Administration (FDA)-approved for the promotion of bone formation in certain procedures. BMPs are seeing more use in oral and maxillofacial surgeries because of recent FDA approval of InFUSE(®) for sinus augmentation and localized alveolar ridge augmentation. However, the utility of BMPs in medical and dental applications is limited by the delivery method. Currently, BMPs are delivered to the surgical site by the implantation of bulky collagen sponges. Here we evaluate the potential of detonation nanodiamonds (NDs) as a delivery vehicle for BMP-2 and basic fibroblast growth factor (bFGF). Nanodiamonds are biocompatible, 4- to 5-nm carbon nanoparticles that have previously been used to deliver a wide variety of molecules, including proteins and peptides. We find that both BMP-2 and bFGF are readily loaded onto NDs by physisorption, forming a stable colloidal solution, and are triggered to release in slightly acidic conditions. Simultaneous delivery of BMP-2 and bFGF by ND induces differentiation and proliferation in osteoblast progenitor cells. Overall, we find that NDs provide an effective injectable alternative for the delivery of BMP-2 and bFGF to promote bone formation. PMID:24045646

Moore, L; Gatica, M; Kim, H; Osawa, E; Ho, D

2013-09-17

11

Online CME usage patterns.  

PubMed

The paper reports the findings of the analysis of a sample of 829 online Continuous Medical Education (CME) enrolments aimed at inspecting users' preferences and behaviours. The contents of the analyzed course are provided as online SCORM (Sharable Content Object Reference Model) resources together with the corresponding Pdf downloadable versions allowing different usage patterns (online only, Pdf only, online AND Pdf, mixed online OR Pdf). The results point out that there is not a specific preference for one of the four patterns and that most of the users access both navigable modules and Pdf documents. Demographic characteristics and initial knowledge level do not influence the choice of a specific usage pattern that probably depends on internal or context factors. From the point of view of knowledge acquisition, the four patterns are equivalent. As regards users' behaviour, the analysis has pointed out two issues: 1) the attitude to conclude the course in a short time and to reach good test scores, but not the excellence; 2) learning activity tracing data were not available for all the enrolments. Cues for discussion are proposed. PMID:21893749

Mazzoleni, M Cristina; Rognoni, Carla; Finozzi, Enrico; Giorgi, Ines; Pagani, Marco; Imbriani, Marcello

2011-01-01

12

Performance improvement CME: adult ADHD.  

PubMed

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent psychiatric disorders and is now understood to be a lifelong condition for most individuals. Unfortunately, many adults with ADHD are not being diagnosed, possibly due to insufficient diagnostic criteria, the complex presentation of the disorder, and a reluctance by physicians to diagnose the disorder in adults. Additionally, many of those who have been diagnosed with ADHD do not receive adequate treatment despite the availability of established and effective agents. Performance Improvement CME (PI CME) is an educational activity in which clinicians retrospectively assess their current clinical practice, choose areas for improvement and implement interventions based on treatment guidelines and health care standards, and then re-evaluate their clinical practice to assess the improvements made. This PI CME activity focuses on improving the diagnosis and treatment of adult ADHD. PMID:21527121

Adler, Lenard A; Barkley, Russell A; Newcorn, Jeffrey H

2011-04-01

13

Numerical models of Oort Cloud formation and comet delivery  

NASA Astrophysics Data System (ADS)

I use a newly designed numerical algorithm to simulate the dynamics of the Oort Cloud. The processes I model are the formation of the cloud, the current delivery of comets to the planetary region, and long-period comet production during comet showers. Concerning the cloud's formation, I find that the Sun's birth environment dramatically affects the structure of the inner Oort Cloud as well as the amount of material trapped in this region. In addition, the structure of this reservoir is also sensitive to the Sun's orbital history in the Milky Way. This raises the possibility that constraining our inner Oort Cloud's properties can constrain the Sun's dynamical history. In this regard, I use my simulations of comet delivery to better understand what the population of comets passing through the planetary region can tell us about the inner Oort Cloud. I find that the inner Oort Cloud (rather than the scattered disk) dominates the production of planet-crossing TNOs with perihelia beyond 15 AU and semimajor axes greater than a few hundred AU. My results indicate that two objects representing this population (2000 00 67 and 2006 SQ 372 ) have already been detected, and the detection of many analogous objects can constrain the inner Oort Cloud. In addition, these simulations of comet delivery also demonstrate that, contrary to previous understanding, the inner Oort Cloud is a significant and perhaps the dominant source of known long-period comets. This result can be used to place the first observationally motivated upper limit on the inner Oort Cloud's population. Finally, with this maximum population value, I use my comet shower simulations to show that comet showers are unlikely to be responsible for more than one minor extinction event since the Cambrian Explosion.

Kaib, Nathan A.

14

CME Autmatic Hammer Operations Bulletin.  

National Technical Information Service (NTIS)

This report is a summary of experience with the Central Mine Equipment (CME) automatic hammer is run by a hydraulic chain-cam lifting system, and the drop height of the hammer depends on the speed of the chain cam. This report addresses energy transmissio...

J. A. Farrar D. Chitwood

1999-01-01

15

Reflections on CME Congress 2012  

ERIC Educational Resources Information Center

|This commentary reflects the author's impressions of Continuing Medical Education (CME) Congress 2012, a provocative international conference on professional development and quality improvement in the health professions that took place in Toronto, Ontario, last spring. The sessions he attended and conversations he had with other attendees were…

Knox, Alan B.

2013-01-01

16

Evolution of CME-driven Shocks in the Lower Corona for the October-November 2003 Events  

Microsoft Academic Search

While it is generally accepted that the largest energetic particle events are created by CME-driven shocks in interplanetary space, the relative importance of CME-driven shocks versus flare-related processes in creating energetic particles low in the corona is not understood and is an area of active research. We analyzed the formation of CME driven shocks in the lower corona for the

M. Opher; W. Manchester; T. Gombosi; P. Liewer; I. Roussev; I. Sokolov; D. Dezeeuw; G. Toth

2005-01-01

17

Localized insulin-like growth factor I delivery to enhance new bone formation  

Microsoft Academic Search

Insulin-like growth factor I (IGF I) exerts an important role during skeletal growth and bone formation. Therefore, its localized delivery appears attractive for the treatment of bone defects. To prolong IGF I delivery, we entrapped the protein into biodegradable poly(lactide-co-glycolide) microspheres (PLGA MS) and evaluated the potential of this delivery system for new bone formation in two defect models of

Lorenz Meinel; Evangelos Zoidis; Jürgen Zapf; Paulo Hassa; Michael O Hottiger; Jörg A Auer; Rebecca Schneider; Bruno Gander; Vera Luginbuehl; Regula Bettschart-Wolfisberger; Oscar E Illi; Hans P Merkle; Brigitte von Rechenberg

2003-01-01

18

SOHO Catches Aug 7th Solar CME  

NASA Video Gallery

This Solar and Heliospheric Observatory (SOHO) coronagraph video shows a portion of the Aug. 7th solar eruption that resulted in another coronal mass ejection (CME) heading toward Earth. The major CME (appearing on left) was not directed towards Earth but a smaller portion (bottom right) will skim Earth's magnetic field on Aug. 9 & 10 resulting in another round of high latitude aurora.

Holly Zell

2010-08-13

19

Low oxidation state gallium compounds. Synthesis and characterization of Ga(CH2CMe3)n  

NASA Astrophysics Data System (ADS)

The new organogallium(I) compound (Ga(CH2CMe3))n has been prepared by the reduction of Ga(CH2CMe3)2Cl by using either sodium or lithium with naphthalene in THF. When the reagents were combined at -78 C, a yellow intermediate, a neopentylgallium(III) derivative of dihydronaphthalene C10H8(Ga(CH2CMe3)2)2 dot 2 MCl (M = Li, Na) was formed. Warming of the solution to 0-25 C resulted in decomposition of the yellow intermediate and formation of a reddish brown solution of Ga(CH2CMe3))n, Ga(CH2CMe3)3, C10H8, and either NaCl or LiCl. The gallium(I) product was a vitreous solid and was characterized by complete elemental analyses, hydrolyses with HCl/H2O and with DCl/D2O, oxidation with HgCl2 and with I2, cryoscopic molecular weight studies in benzene solution, and IR and NMR spectroscopic studies. All data support the conclusion that (Ga(CH2CMe3))n exists as a mixture of species which are gallium cages. The numbers of gallium atoms in these cages might range from 6 to 12 atoms.

Beachley, O. T., Jr.; Pazik, John C.; Noble, Matthew J.

1994-08-01

20

Simvastatin-loaded ?-TCP drug delivery system induces bone formation and prevents rhabdomyolysis in OVX mice.  

PubMed

Bone formation and regeneration is a prolonged process that requires a slow drug release system to assist in the long-term recovery. A drug-delivery system is developed that allows for the controlled release of simvastin, without exhibiting the side effects associated with high concentrations of simvastatin, and is still capable of inducing constant bone formation. PMID:23184712

Chou, Joshua; Ito, Tomoko; Otsuka, Makoto; Ben-Nissan, Besim; Milthorpe, Bruce

2012-11-26

21

Solar Back-sided Halo CME  

NASA Video Gallery

The Sun erupted with several CMEs (coronal mass ejections) during a period just over a day (Nov. 8-9, 2012), the largest of which was a halo CME. This CME appears to have originated from an active region barely out of view on the left side of the Sun and was headed behind the Sun. A halo CME is one where the ejected material appears to form a roughly circular shape around the Sun, not because it surrounds the Sun but because it is moving directly toward or away from the observer. These images combine SDO's video of the Sun (in gold) in extreme UV light superimposed on a view of the corona from SOHO's LASCO instrument (in red).

Holly Zell

2012-11-29

22

CME Flux ropes: Origins, Characteristics and Consequences  

NASA Astrophysics Data System (ADS)

A CME flux rope is a magnetic structure propelled from the Sun during a solar eruption, which often includes a solar flare, a prominence disruption and the CME. CME flux ropes begin at the low corona over the polarity inversion lines (PILs) of the photospheric radial magnetic field. Solar eruptions have been explained as the loss of equilibrium of flux ropes held down by the coronal field. The flux ropes may be emerged from the solar interior or gradually formed in the low corona. Alternatively, the CME flux ropes form during the eruptions by magnetic reconnection under the sheared coronal arcades over the PILs. The source regions of CMEs can be large sunspot active regions with kilogauss magnetic field, quiescent prominences in decayed magnetic field and coronal streamers over the quiet Sun. After the initiation of the eruption, the CME flux ropes undergo acceleration (deceleration), expansion, rotation, distortion and interaction with the ambient solar wind during the propagation in the heliosphere. The internal plasma and magnetic field of the CME flux ropes are measured when the structure encounters a spacecraft in the solar wind. The interplanetary CMEs (ICMEs) at 1AU have radial dimension ranging 0.1 to 0.5 AU, speed ranging 300 to 1000 km/s, and internal magnetic field ranging 10 to 50 nT. A significant fraction of ICMEs are flux rope type or magnetic clouds (MCs), the field of which are quite consistent with the field produced by a cylindrical flux rope with various orientations. Most MCs produce out-of ecliptic plane magnetic field. When the MCs contain both northward and southward field, they are bipolar MCs. The polarity of the bipolar MCs has been found to have a solar cycle dependence and follows the solar dipole field. MCs containing extended strong southward field cause the most intense geomagnetic disturbances.

Li, Y.; Luhmann, J. G.; Lynch, B. J.; Kilpua, E.

2011-12-01

23

A Kinetic Model for the Radio CME  

NASA Astrophysics Data System (ADS)

Current studies on Coronal Mass Ejections (CMEs) are mostly concentrated on their macroscopic properties as measured on White-Light images. On the other hand, radio emissions from CMEs carry the information of high energy particles associated with them, but usually without spatial information. In this regard, the rare radio maps of the 1998 April 20 CME obtained with the Nancay radioheliograph between 164 and 432 MHz (called a radio CME by Bastian et al. in 2001) offer an exceptional opportunity to explore the spatial distribution of high energy electrons inside the CME loop. We present a detailed kinetic model for the radio CME employing the lower hybrid (LH) waves excited by the CME shock as the primary electron acceleration mechanism, and magnetic mirroring and Coulomb collisions as the propagation effects inside the expanding loop. The main constraint in this modeling comes from the fact that the LH waves accelerate electrons parallel to the magnetic field and the accelerated electrons should gain, during propagation, sufficient amount of the perpendicular momentum to emit the synchrotron radiation as observed. The relative magnetic field variation responsible for the magnetic mirroring is inferred from the geometrical shape of the CME on the images of the Large Angle and Spectrometric Coronagraph Experiment (LASCO), and the field strength and the amplitude of the LH waves are determined from the observed radio spectra. The modeling is focused on the spatial distribution of the LH waves most plausible to explain the radio maps, and the result is discussed in relation to the associated shock property.

Lee, Jeongwoo; Gary, D. E.

2009-05-01

24

Mechanism of membranous tunnelling nanotube formation in viral genome delivery.  

PubMed

In internal membrane-containing viruses, a lipid vesicle enclosed by the icosahedral capsid protects the genome. It has been postulated that this internal membrane is the genome delivery device of the virus. Viruses built with this architectural principle infect hosts in all three domains of cellular life. Here, using a combination of electron microscopy techniques, we investigate bacteriophage PRD1, the best understood model for such viruses, to unveil the mechanism behind the genome translocation across the cell envelope. To deliver its double-stranded DNA, the icosahedral protein-rich virus membrane transforms into a tubular structure protruding from one of the 12 vertices of the capsid. We suggest that this viral nanotube exits from the same vertex used for DNA packaging, which is biochemically distinct from the other 11. The tube crosses the capsid through an aperture corresponding to the loss of the peripentonal P3 major capsid protein trimers, penton protein P31 and membrane protein P16. The remodeling of the internal viral membrane is nucleated by changes in osmolarity and loss of capsid-membrane interactions as consequence of the de-capping of the vertices. This engages the polymerization of the tail tube, which is structured by membrane-associated proteins. We have observed that the proteo-lipidic tube in vivo can pierce the gram-negative bacterial cell envelope allowing the viral genome to be shuttled to the host cell. The internal diameter of the tube allows one double-stranded DNA chain to be translocated. We conclude that the assembly principles of the viral tunneling nanotube take advantage of proteo-lipid interactions that confer to the tail tube elastic, mechanical and functional properties employed also in other protein-membrane systems. PMID:24086111

Peralta, Bibiana; Gil-Carton, David; Castaño-Díez, Daniel; Bertin, Aurelie; Boulogne, Claire; Oksanen, Hanna M; Bamford, Dennis H; Abrescia, Nicola G A

2013-09-24

25

Mechanism of Membranous Tunnelling Nanotube Formation in Viral Genome Delivery  

PubMed Central

In internal membrane-containing viruses, a lipid vesicle enclosed by the icosahedral capsid protects the genome. It has been postulated that this internal membrane is the genome delivery device of the virus. Viruses built with this architectural principle infect hosts in all three domains of cellular life. Here, using a combination of electron microscopy techniques, we investigate bacteriophage PRD1, the best understood model for such viruses, to unveil the mechanism behind the genome translocation across the cell envelope. To deliver its double-stranded DNA, the icosahedral protein-rich virus membrane transforms into a tubular structure protruding from one of the 12 vertices of the capsid. We suggest that this viral nanotube exits from the same vertex used for DNA packaging, which is biochemically distinct from the other 11. The tube crosses the capsid through an aperture corresponding to the loss of the peripentonal P3 major capsid protein trimers, penton protein P31 and membrane protein P16. The remodeling of the internal viral membrane is nucleated by changes in osmolarity and loss of capsid-membrane interactions as consequence of the de-capping of the vertices. This engages the polymerization of the tail tube, which is structured by membrane-associated proteins. We have observed that the proteo-lipidic tube in vivo can pierce the gram-negative bacterial cell envelope allowing the viral genome to be shuttled to the host cell. The internal diameter of the tube allows one double-stranded DNA chain to be translocated. We conclude that the assembly principles of the viral tunneling nanotube take advantage of proteo-lipid interactions that confer to the tail tube elastic, mechanical and functional properties employed also in other protein-membrane systems.

Peralta, Bibiana; Gil-Carton, David; Castano-Diez, Daniel; Bertin, Aurelie; Boulogne, Claire; Oksanen, Hanna M.; Bamford, Dennis H.; Abrescia, Nicola G. A.

2013-01-01

26

MuMiVA: A Multimedia Delivery Platform Using Format-Agnostic, XML-Driven Content Adaptation  

Microsoft Academic Search

Due to the increasing heterogeneity in the current multimedia landscape, the delivery of multimedia content has become an important issue today. This heterogeneity is not only reflected by a plethora of different usage environments, but also by the presence of multiple (scalable) coding formats. Therefore, format-independent adaptation engines have to be used within a multimedia delivery platform, which are able

Davy Van Deursen; Sarah De Bruyne; Wim Van Lancker; Wesley De Neve; Davy De Schrijver; Hermann Hellwagner; Rik Van de Walle

2007-01-01

27

CME and Change in Practice: An Alternative Perspective.  

ERIC Educational Resources Information Center

|Results of a study by the American College of Cardiology revealed that continuing medical education (CME) courses contain relatively little information that is new to the audience, that other influences on practice interact with CME content, and that change attributable to CME is subtle and often delayed. (JOW)|

Wergin, Jon F.; And Others

1988-01-01

28

Learning to Collaborate: A Case Study of Performance Improvement CME  

ERIC Educational Resources Information Center

|Introduction: Performance Improvement Continuing Medical Education (PI CME) is a mechanism for joining quality improvement (QI) in health care to continuing medical education (CME) systems together. Although QI practices and CME approaches have been recognized for years, what emerges from their integration is largely unfamiliar, because it…

Shershneva, Marianna B.; Mullikin, Elizabeth A.; Loose, Anne-Sophie; Olson, Curtis A.

2008-01-01

29

Solar Filament Eruption Sends CME Towards Earth  

NASA Video Gallery

Full disk view of magnetic solar filament erupting during the early hours of February 24, 2012. A coronal mass ejections (CME) directed toward Earth accompanied the filament eruption. This video was taken by the Solar Dynamic Observatory in extreme ultraviolet wavelength (304 angstrom).

Holly Zell

2012-02-25

30

Characteristics of Kinematics of a Coronal Mass Ejection during the 2010 August 1 CME-CME Interaction Event  

NASA Astrophysics Data System (ADS)

We study the interaction of two successive coronal mass ejections (CMEs) during the 2010 August 1 events using STEREO/SECCHI COR and heliospheric imager (HI) data. We obtain the direction of motion for both CMEs by applying several independent reconstruction methods and find that the CMEs head in similar directions. This provides evidence that a full interaction takes place between the two CMEs that can be observed in the HI1 field of view. The full de-projected kinematics of the faster CME from Sun to Earth is derived by combining remote observations with in situ measurements of the CME at 1 AU. The speed profile of the faster CME (CME2; ~1200 km s-1) shows a strong deceleration over the distance range at which it reaches the slower, preceding CME (CME1; ~700 km s-1). By applying a drag-based model we are able to reproduce the kinematical profile of CME2, suggesting that CME1 represents a magnetohydrodynamic obstacle for CME2 and that, after the interaction, the merged entity propagates as a single structure in an ambient flow of speed and density typical for quiet solar wind conditions. Observational facts show that magnetic forces may contribute to the enhanced deceleration of CME2. We speculate that the increase in magnetic tension and pressure, when CME2 bends and compresses the magnetic field lines of CME1, increases the efficiency of drag.

Temmer, Manuela; Vršnak, Bojan; Rollett, Tanja; Bein, Bianca; de Koning, Curt A.; Liu, Ying; Bosman, Eckhard; Davies, Jackie A.; Möstl, Christian; Žic, Tomislav; Veronig, Astrid M.; Bothmer, Volker; Harrison, Richard; Nitta, Nariaki; Bisi, Mario; Flor, Olga; Eastwood, Jonathan; Odstrcil, Dusan; Forsyth, Robert

2012-04-01

31

CHARACTERISTICS OF KINEMATICS OF A CORONAL MASS EJECTION DURING THE 2010 AUGUST 1 CME-CME INTERACTION EVENT  

SciTech Connect

We study the interaction of two successive coronal mass ejections (CMEs) during the 2010 August 1 events using STEREO/SECCHI COR and heliospheric imager (HI) data. We obtain the direction of motion for both CMEs by applying several independent reconstruction methods and find that the CMEs head in similar directions. This provides evidence that a full interaction takes place between the two CMEs that can be observed in the HI1 field of view. The full de-projected kinematics of the faster CME from Sun to Earth is derived by combining remote observations with in situ measurements of the CME at 1 AU. The speed profile of the faster CME (CME2; {approx}1200 km s{sup -1}) shows a strong deceleration over the distance range at which it reaches the slower, preceding CME (CME1; {approx}700 km s{sup -1}). By applying a drag-based model we are able to reproduce the kinematical profile of CME2, suggesting that CME1 represents a magnetohydrodynamic obstacle for CME2 and that, after the interaction, the merged entity propagates as a single structure in an ambient flow of speed and density typical for quiet solar wind conditions. Observational facts show that magnetic forces may contribute to the enhanced deceleration of CME2. We speculate that the increase in magnetic tension and pressure, when CME2 bends and compresses the magnetic field lines of CME1, increases the efficiency of drag.

Temmer, Manuela; Rollett, Tanja; Bein, Bianca; Moestl, Christian; Veronig, Astrid M.; Flor, Olga [Kanzelhoehe Observatory-IGAM, Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Vrsnak, Bojan; Zic, Tomislav [Hvar Observatory, Faculty of Geodesy, University of Zagreb, Kaciceva 26, HR-10000 Zagreb (Croatia); De Koning, Curt A. [NOAA Space Weather Prediction Center, Boulder, CO 80305 (United States); Liu, Ying [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Bosman, Eckhard [Space Research Institute, Austrian Academy of Sciences, A-8042 Graz (Austria); Davies, Jackie A.; Bothmer, Volker [Institut fuer Astrophysik, Goettingen University, Friedrich-Hund Platz 1, D-37077 Goettingen (Germany); Harrison, Richard [RAL Space, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Nitta, Nariaki [Solar and Astrophysics Laboratory, Lockheed Martin Advanced Technology Centre, Palo Alto, CA 94304-1191 (United States); Bisi, Mario [Institute of Mathematics and Physics, Aberystwyth University, Ceredigion SY23 3BZ (United Kingdom); Eastwood, Jonathan; Forsyth, Robert [The Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Odstrcil, Dusan, E-mail: mat@igam.uni-graz.at [Computational and Data Sciences, George Mason University/NASA Goddard Space Flight Center, Mail Code 674, Greenbelt, MD 20771 (United States)

2012-04-10

32

Intrapericardial Delivery of Gelfoam Enables the Targeted Delivery of Periostin Peptide after Myocardial Infarction by Inducing Fibrin Clot Formation  

PubMed Central

Background Administration of a recombinant peptide of Periostin (rPN) has recently been shown to stimulate cardiomyocyte proliferation and angiogensis after myocardial infarction (MI) [1]. However, strategies for targeting the delivery of rPN to the heart are lacking. Intrapericardial administration of drug-eluting hydrogels may provide a clinically viable strategy for increasing myocardial retention, therapeutic efficacy, and bioactivity of rPN and to decrease systemic re-circulation. Methods and Results We investigated the ability of intrapericardial injections of drug-eluting hydrogels to deliver and prolong the release of rPN to the myocardium in a large animal model of myocardial infarction. Gelfoam is an FDA-approved hemostatic material commonly used in surgery, and is known to stimulate fibrin clot formation. We show that Gelfoam disks loaded with rPN, when implanted within the pericardium or peritoneum of mammals becomes encapsulated within a non-fibrotic fibrin-rich hydrogel, prolonging the in vitro and in vivo release of rPN. Administration into the pericardial cavity of pigs, following a complete occlusion of the left anterior descending artery, leads to greater induction of cardiomyocyte mitosis, increased cardiomyocyte cell cycle activity, and enhanced angiogenesis compared to direct injection of rPN alone. Conclusions The results of this study suggest that intrapericardial drug delivery of Gelfoam, enhanced by triggered clot formation, can be used to effectively deliver rPN to the myocardium in a clinically relevant model of myocardial infarction. The work presented here should enhance the translational potential of pharmaceutical-based strategies that must be targeted to the myocardium.

Polizzotti, Brian D.; Arab, Shima; Kuhn, Bernhard

2012-01-01

33

Radio signatures of CME-streamer interaction  

NASA Astrophysics Data System (ADS)

Recent observational finding of streamer waves using the LASCO white light data presents us interesting physical consequence of CME-streamer interactions [1, 2, 3]. CME-streamer interactions can also manifest themselves in the Type-II-related radio dynamic spectra as recorded by the ground-based or space-borne instruments. A large body of studies exists revealing the possible roles of pre-existing helmet streamers in the radio emission during a solar eruption. In this presentation, we will summary our efforts in classifying the roles of streamers affecting Type-II radio emissions. Generally speaking, there exist two groups of CME-streamer-Type-II events. In the first group, the shock as well as the Type-II radio emission seems to exist prior to the CME-streamer interaction. The interaction can be clearly discerned from the well-defined bump of the Type-II radio dynamic spectra. The spectral bump is a direct result of plasma emissions when the radio emitting region traversing the denser streamer structure. In the other group of events, the Type-II burst is excited as a result of the CME-streamer interaction. Either the shock is formed and radio-emitting electrons are accelerated inside the streamer, or a prior non-emitting shock becomes radio aloud during the interacting process. A novel triangular-streamer-shock model is proposed to interpret the associated electron acceleration inside the streamer. Observational examples of CME-streamer-radio events corresponding to both cases will be presented. [1] Chen, Y., Song, H.Q., Li, B., Xia, L.D., Wu, Z., Fu, H., Li, X., 2010, Astrophys. J. 714, 644 [2] Chen, Y., Feng, S.W., Li, B., Song, H.Q., Xia, L.D., Kong, X.L., Li, X., 2011, Astrophys. J. 728, 147 [3] Feng S. W., Chen Y., Li B., Song H. Q., Kong X. L., Xia L. D., Feng, X. S., 2011, Sol. Phys., DOI 10.1007/s11207-011-9814-6

CHEN, Y.; Feng, S.; Kong, X.; Li, G.; Song, H.

2011-12-01

34

FAST AND EFFECTIVE REMEDIES FOR THE DELIVERY OF WEB-BASED FORMATIVE ASSESSMENT MATERIALS  

Microsoft Academic Search

Academics at higher education institutions are turning increasingly to web-based technologies to supplement and enhance their existing face-to-face teaching and develop richer learning environments for distance learners. An important part of this online teaching is the delivery of effective formative assessment allowing the student to test their knowledge and manage their learning efficiently. Staff engaged in this activity are faced

Joanna Bull; Patrick Zhao; David Binks; Alison Foulkes; Paul Thomas; Clive Young

35

SpatioYtemporal VEGF and PDGF Delivery Patterns Blood Vessel Formation and Maturation  

Microsoft Academic Search

Purpose. Biological mechanisms of tissue regeneration are often complex, involving the tightly coordinated spatial and temporal presentation of multiple factors. We investigated whether spatially compartmentalized and sequential delivery of factors can be used to pattern new blood vessel formation. Materials and Methods. A porous bi-layered poly(lactideYco-glycolide) (PLG) scaffold system was used to locally present vascular endothelial growth factor (VEGF) alone

Ruth R. Chen; Eduardo A. Silva; William W. Yuen; David J. Mooney

2007-01-01

36

Simulations of the CME-Flare Relationship  

NASA Astrophysics Data System (ADS)

Observations of coronal mass ejections (CMEs) and solar flares have revealed a high correlation between the acceleration of the ejecta and the plasma heating and particle acceleration signified by the soft and hard X-ray emissions of the associated flare. The latter are generally thought to result from magnetic reconnection. This finding has stimulated the discussion of the CME-flare relationship, but at the same time it has made it difficult to find a conclusive answer as to whether magnetic reconnection or an ideal MHD instability is the prime cause of the eruptions. Numerical simulations of unstable flux ropes will be presented that are in very satisfactory quantitative agreement with erupting filaments, both, confined to the corona and ejective (i.e., developing into a CME). Some of these simulations indeed show a high degree of synchronization between the initial exponential acceleration of the flux rope, due to the ideal MHD instability, and the development of reconnection flows. However, others show a very delayed onset of reconnection, even after the flux rope's acceleration peak. In addition, the reconnection flows generally lag behind the motions driven by the ideal instability as the flux rope rise velocity nears the saturation phase. Comparison of the simulation results with observations suggests that the ideal MHD process is the primary driver of the coupled CME-flare phenomenon. The strong differences in the degree of synchronization, which the simulated systems show in the main rise phase of the eruption, are related to the magnetic topology prior to the eruption. Given the observational result of a high correlation between CME and flare development (Zhang & Dere 2006), these simulations yield constraints on the topology and lead us to conclude that a seed for a reconnecting current sheet must typically be present already at the onset of the eruption.

Kliem, B.; Török, T.; Forbes, T. G.

2008-12-01

37

Simulations of the CME-Flare Relationship  

NASA Astrophysics Data System (ADS)

Observations of coronal mass ejections (CMEs) and solar flares have revealed a high correlation between the acceleration of the ejecta and the plasma heating and particle acceleration signified by the soft and hard X-ray emissions of the associated flare. The latter are generally thought to result from magnetic reconnection. This finding has stimulated the discussion of the CME-flare relationship, but at the same time it has made it difficult to find a conclusive answer as to whether magnetic reconnection or an ideal MHD instability is the prime cause of the eruptions. Numerical simulations of unstable flux ropes will be presented that are in very satisfactory quantitative agreement with erupting filaments, both, confined to the corona and ejective (i.e., developing into a CME). Some of these simulations indeed show a high degree of synchronization between the initial exponential acceleration of the flux rope, due to the ideal MHD instability, and the development of reconnection flows. However, others show a very delayed onset of reconnection, even after the flux rope's acceleration peak. In addition, the reconnection flows generally lag behind the motions driven by the ideal instability as the flux rope rise velocity nears the saturation phase. Both findings indicate that the ideal MHD process is the primary driver of the coupled CME-flare phenomenon. The strong differences in the degree of synchronization, which the simulated systems show in the main rise phase of the eruption, are related to the magnetic topology prior to the eruption. Given the observational result of a high correlation between CME and flare development (Zhang & Dere 2006), these simulations yield constraints on the topology and lead us to conclude that a seed for a reconnecting current sheet must typically be present already at the onset of the eruption.

Kliem, B.; Török, T.

2008-09-01

38

CME Magnetic Structure and Magnetic Cloud Signature  

NASA Astrophysics Data System (ADS)

An interplanetary coronal mass ejection (ICME) is the counterpart of a coronal mass ejection by definition. However, the relationship between the magnetic structures of the CMEs and that of the situ observations of ICMEs is still quite far from clear, due to observational gaps and the state of our understanding of CMEs. Some studies suggested that the magnetic cloud (MC, a group of ICMEs with fluxrope signatures) magnetic polarity follows the solar large scale magnetic field, and others suggested it follows the local magnetic field of the CME source region. Recent studies found that the relationship is more complex. While solar cycle dependence of the magnetic signature of MCs is clearly evident, the polarity of the MCs does not reverse at the same time when the solar large scale field reverses around solar maximum, but begins to have mixed polarities, and the new polarity may only prevail at the midst of the declining phase. Interestingly, in an independent study of the magnetic topology at the CME source regions, we found a similar solar cycle dependence of the bipolar and quadrupolar topologie. In this work, the link between CMEs and ICMEs is made and the results will shed light on our understanding about the relationship between CME and ICME magnetic structures and how these structures are related to solar local and large scale magnetic fields.Acknowledgement: ATM/NSF-0451438, SRT/NASA-NNG06GE51G and CISM/NSF.

Li, Yan; Luhmann, J.

2006-06-01

39

Statistical Study of the CME-Solar Flares Associated Events  

NASA Astrophysics Data System (ADS)

The aim of this paper is studying the relation between the coronal mass ejections (CMEs), and their associated solar flares. I used the CMEs data (obtained from CME catalogue) which observed by SOHO/LASCO, during the Solar Cycle 23rd (1996-2006), during this period I selected 12,433 CME records. Also I used the X-ray flares data which provided geostationary operational environmental satellite (GOES), during the same interval in the 1-8 Å GOES channel, the recorded flare events are 22,688. I filtered these CMEs and solar flare events to select 529 CME-Flare events. I found that there is a moderate relation between the solar flare fluxes and their associated CME energies, where R = 58 %. In addition I found that 61 % of the CME-Flare associated events ejected from the solar surface after the occurrence of the associated flare. Furthermore I found that the CME-Flare relation improved during the period of high solar activity. Finally, I examined the CME association rate as a function of flare longitude and I found that the CME association rate of the total 529 selected CME-Flare events are mostly disk-Flare events.

Youssef, M.

2013-06-01

40

Deflected Propagation ---- A Factor Deciding the Geoeffectiveness of A CME  

NASA Astrophysics Data System (ADS)

To answer the question if a CME can cause a significant change of the states of geo-space, the first issue we have to address is whether or not the CME will intersect with the Earth or what the trajectory of the CME is. From several observational cases and statistical studies, we show that the deflected propagations of CMEs are a common phenomenon. The amount of the deflection could be as large as several tens degrees in either latitude, longitude or both. Thus, an on-disk CME may not necessarily encounter the Earth, while a limb CME may be able to hit the Earth. Roughly, the CMEs' deflections can be classified as two different kinds. One is the deflection occurring in the corona, in which the CME's trajectory is controled by the distribution of the energy density of undisturbed coronal magnetic field. The other is that happenning in the IP space and in the ecliptic plane, in which the direction of the CME's propagation will be changed by the preceding or trailing background solar wind plasma depending on the velocity difference between the CME and ambient solar wind. Two models are proposed to describe the two different CME deflection behaviors, respectively. By applying the models to several cases, we may show that the trajectories of these CMEs predicted by the models match the observations fairly well.

Wang, Y.; Shen, C.; Liu, J.; Gui, B.; Wang, S.

2010-12-01

41

Spatio–temporal VEGF and PDGF Delivery Patterns Blood Vessel Formation and Maturation  

Microsoft Academic Search

\\u000a Purpose  Biological mechanisms of tissue regeneration are often complex, involving the tightly coordinated spatial and temporal presentation\\u000a of multiple factors. We investigated whether spatially compartmentalized and sequential delivery of factors can be used to\\u000a pattern new blood vessel formation.\\u000a \\u000a \\u000a \\u000a Materials and Methods  A porous bi-layered poly(lactide–co-glycolide) (PLG) scaffold system was used to locally present vascular endothelial growth\\u000a factor (VEGF) alone in one

Ruth R. Chen; Eduardo A. Silva; William W. Yuen; David J. Mooney

2007-01-01

42

Delivery.  

PubMed

Enthusiasm greeted the development of synthetic organic insecticides in the mid-twentieth century, only to see this give way to dismay and eventually scepticism and outright opposition by some. Regardless of how anyone feels about this issue, insecticides and other pesticides have become indispensable, which creates something of a dilemma. Possibly as a result of the shift in public attitude towards insecticides, genetic engineering of microbes was first met with scepticism and caution among scientists. Later, the development of genetically modified crop plants was met with an attitude that hardened into both acceptance and hard-core resistance. Transgenic insects, which came along at the dawn of the twenty-first century, encountered an entrenched opposition. Those of us responsible for studying the protection of crops have been affected more or less by these protagonist and antagonistic positions, and the experiences have often left one thoughtfully mystified as decisions are made by non-participants. Most of the issues boil down to concerns over delivery mechanisms. © 2013 Society of Chemical Industry. PMID:23852646

Miller, Thomas A

2013-08-09

43

Observations of a CME heated by flare-accelerated electrons  

NASA Astrophysics Data System (ADS)

We present an updated analysis of a RHESSI observation of flare-accelerated electrons in the core of a coronal mass ejection (CME) and examine their role in heating the CME. Previous CME observations have found remarkably high temperatures in the core. A joint observation by RHESSI and AIA of a partly occulted flare on 2010 November 3 allows us to test the hypothesis that this excess energy is collisionally deposited by flare-accelerated electrons. Extreme ultraviolet (EUV) images from AIA show an ejected plasmoid forming the CME core and sheath, with isothermal multifilter analysis revealing temperatures of > 11 MK in the core. RHESSI images produced via the Two-Step CLEAN algorithm reveal a large 100 x 50 arcsec2), diffuse hard X-ray source matching the location, shape, and evolution of the AIA plasma, indicating that the emerging CME core is filled with energetic electrons. Spectroscopy demonstrates that the nonthermal electrons contain enough energy to heat the CME. The time integral of the EUV emission matches the hard X-ray light curve (similar to the ``Neupert effect'' observed in soft and hard X-ray time profiles), directly linking the CME temperature increase with the nonthermal electron energy loss. This is the most direct observation to date of energetic flare electrons heating a CME, emphasizing the close relationship of the two in solar eruptive events.

Glesener, Lindsay; Krucker, S.; Bain, H.; Lin, R. P.

2013-07-01

44

Attendees' Perceptions of Commercial Influence in Noncommercially Funded CME Programs  

ERIC Educational Resources Information Center

|Introduction: The controversy surrounding commercial support for continuing medical education (CME) programs has led to policy changes, but data show no significant difference in perceived bias between commercial and noncommercial CME. Indeed, what attendees perceive as commercial influence is not fully understood. We sought to clarify what…

Goldfarb, Elizabeth; Baer, Lee; Fromson, John A.; Gorrindo, Tristan; Iodice, Kristin E.; Birnbaum, Robert J.

2012-01-01

45

Evaluating Conflicts of Interest in Research Presented in CME Venues  

ERIC Educational Resources Information Center

Introduction: There is much in the literature regarding the potential for commercial bias in clinical research and in continuing medical education (CME), but no studies were found regarding the potential for bias in reporting original research in CME venues. This pilot study investigated the presence of perceived bias in oral and print content of…

Davis, Nancy L.; Galliher, James M.; Spano, Mindy S.; Main, Deborah S.; Brannigan, Michael; Pace, Wilson D.

2008-01-01

46

Feasibility of a Knowledge Translation CME Program: "Courriels Cochrane"  

ERIC Educational Resources Information Center

Introduction: Systematic literature reviews provide best evidence, but are underused by clinicians. Thus, integrating Cochrane reviews into continuing medical education (CME) is challenging. We designed a pilot CME program where summaries of Cochrane reviews ("Courriels Cochrane") were disseminated by e-mail. Program participants automatically…

Pluye, Pierre; Grad, Roland; Granikov, Vera; Theriault, Guylene; Fremont, Pierre; Burnand, Bernard; Mercer, Jay; Marlow, Bernard; Arroll, Bruce; Luconi, Francesca; Legare, France; Labrecque, Michel; Ladouceur, Roger; Bouthillier, France; Sridhar, Soumya Bindiganavile; Moscovici, Jonathan

2012-01-01

47

Developing an Instrument to Measure Bias in CME  

ERIC Educational Resources Information Center

|Introduction: The pharmaceutical industry, by funding over 60% of programs in the United States and Canada, plays a major role in continuing medical education (CME), but there are concerns about bias in such CME programs. Bias is difficult to define, and currently no tool is available to measure it. Methods: Representatives from industry and…

Takhar, Jatinder; Dixon, Dave; Donahue, Jill; Marlow, Bernard; Campbell, Craig; Silver, Ivan; Eadie, Jason; Monette, Celine; Rohan, Ivan; Sriharan, Abi; Raymond, Kathryn; Macnab, Jennifer

2007-01-01

48

Comprehensive STEREO Observations of the 2008 February 4 CME  

NASA Astrophysics Data System (ADS)

Thanks to the two Heliospheric Imagers that are part of STEREO's SECCHI instrument package, the two STEREO spacecraft are the first that are capable of following a CME continuously from the Sun all the way to 1 AU, where the PLASTIC and IMPACT instruments on the spacecraft can then also provide in situ information on the CME, assuming it hits one of the the two satellites. We present the first kinematic study of a CME that has been observed in such a comprehensive manner. The event begins on 2008 February 4 and is successfully tracked by STEREO-A to 1 AU where it hits STEREO-B on February 7. This is therefore a good example of STEREO's capability for one satellite (STEREO-A in this case) to observe a white-light CME front hitting the other satellite (STEREO-B in this case) at the same time as that second satellite is measuring the CME properties in situ.

Wood, B. E.; Howard, R. A.; Plunkett, S. P.; Socker, D. G.

2008-12-01

49

Nanoparticle formation by using shellac and chitosan for a protein delivery system.  

PubMed

The potential of using two natural polymers (chitosan and shellac) for the formation of nanoparticles by the process of ionic cross-linking to encapsulate bovine serum albumin, a model protein was investigated. Depending on the concentrations of chitosan, shellac and bovine serum albumin, three physical states - nanoparticle, aggregation, and solution could be observed as a result of the electrostatic force. The formation of nanoparticles was due to the balance between the repulsion force and attractive force while the imbalance between both forces resulted in the formation of aggregation and solution. The Fourier transform infrared spectroscopy and differential scanning calorimetry were applied to prove the nanoparticle formation. The particle size was characterized by the light scattering technique and was found in the range between 100 and 300 nm. The morphology of the particles, detected by transmission electron microscopy was spherical shape. The result showed that the zeta potential of the nanoparticles possessed positive charges. The concentrations of chitosan, shellac and bovine serum albumin had an influence on the physicochemical properties of the nanoparticles such as the particle size, the zeta potential, the encapsulation, the loading efficiencies and the cumulative release. Therefore, chitosan and shellac could be used to form nanoparticles for protein delivery by the ionic cross-linking method. PMID:22568768

Kraisit, Pakorn; Limmatvapirat, Sontaya; Nunthanid, Jurairat; Sriamornsak, Pornsak; Luangtana-anan, Manee

2012-05-09

50

Plasma Radiation and Acceleration Effectiveness of CME-driven Shocks  

NASA Astrophysics Data System (ADS)

CME-driven shocks are effective radio radiation generators and accelerators for Solar Energetic Particles (SEPs). We present simulated 3 D time-dependent radio maps of second order plasma radiation generated by CME- driven shocks. The CME with its shock is simulated with the 3 D BATS-R-US CME model developed at the University of Michigan. The radiation is simulated using a kinetic plasma model that includes shock drift acceleration of electrons and stochastic growth theory of Langmuir waves. We find that in a realistic 3 D environment of magnetic field and solar wind outflow of the Sun the CME-driven shock shows a detailed spatial structure of the density, which is responsible for the fine structure of type II radio bursts. We also show realistic 3 D reconstructions of the magnetic cloud field of the CME, which is accelerated outward by magnetic buoyancy forces in the diverging magnetic field of the Sun. The CME-driven shock is reconstructed by tomography using the maximum jump in the gradient of the entropy. In the vicinity of the shock we determine the Alfven speed of the plasma. This speed profile controls how steep the shock can grow and how stable the shock remains while propagating away from the Sun. Only a steep shock can provide for an effective particle acceleration.

Gopalswamy, N.; Schmidt, J. M.

2008-05-01

51

Numerical simulations of the CME on 2010 April 8  

NASA Astrophysics Data System (ADS)

We present 3D zero-beta ideal MHD simulations of the solar flare/CME event that occurred in Active Region 11060 on 2010 April 8. The initial magnetic configurations of the two simulations are stable nonlinear force-free field and unstable magnetic field models constructed by Su et al. (2011) using the flux rope insertion method. The MHD simulations confirm that the stable model relaxes to a stable equilibrium, while the unstable model erupts as a CME. Comparisons between observations and MHD simulations of the CME are also presented.

Su, Yingna; Kliem, Bernhard; van Ballegooijen, Adriaan; Deluca, Edward

2013-07-01

52

Small-Angle Neutron Scattering and Spontaneous Formation of Unilamellar Vesicles: Potential Vehicles for Drug Delivery  

NASA Astrophysics Data System (ADS)

Unilamellar vesicles (ULVs) are single-bilayer shells with radii commonly between 10 and 100 nm, and are widely used as model membranes, drug delivery systems, microreactors and substrates for a variety of enzymes and proteins. A common method of making ULVs is the extrusion of multilamellar vesicles (MLVs) through synthetic membranes of known pore size. These extruded ULVs are invariably unstable and in due time, revert back to MLVs. Over the years there have been reports of the spontaneous formation of stable ULVs in surfactant, lipid, and lipid/detergent mixtures. These ULVs have sometimes been shown to be monodisperse and their radii were found, almost without exception, to vary with concentration. We have carried-out small-angle neutron scattering (SANS) experiments on a biomimetic system composed of the phospholipids dimyristoyl and dihexanoyl phosphorylcholine (DMPC and DHPC, respectively). Doping DMPC/DHPC multilamellar vesicles with either the negatively charged lipid dimyristoyl phosphorylglycerol (DMPG, net charge -1) or the divalent cation, calcium (Ca2+) leads to the spontaneous formation of monodisperse unilamellar vesicles whose radii are concentration independent, in contrast to previous experimental observations.

Katsaras, John

2004-03-01

53

Scientific Goals of the Cooperative Multiscale Experiment (CME).  

National Technical Information Service (NTIS)

Mesoscale Convective Systems (MCS) form the focus of CME. Recent developments in global climate models, the urgent need to improve the representation of the physics of convection, radiation, the boundary layer, and orography, and the surge of interest in ...

W. Cotton

1993-01-01

54

Evaluation of a Thiolated Chitosan Scaffold for Local Delivery of BMP-2 for Osteogenic Differentiation and Ectopic Bone Formation  

PubMed Central

Thiolated chitosan (Thio-CS) is a well-established pharmaceutical excipient for drug delivery. However, its use as a scaffold for bone formation has not been investigated. The aim of this study was to evaluate the potential of Thio-CS in bone morphogenetic protein-2 (BMP-2) delivery and bone formation. In vitro study showed that BMP-2 interacted with the Thio-CS and did not affect the swelling behavior. The release kinetics of BMP-2 from the Thio-CS was slightly delayed (70%) within 7 days compared with that from collagen gel (Col-gel, 85%), which is widely used in BMP-2 delivery. The BMP-2 released from Thio-CS increased osteoblastic cell differentiation but did not show any cytotoxicity until 21 days. Analysis of the in vivo ectopic bone formation at 4 weeks of posttransplantation showed that use of Thio-CS for BMP-2 delivery induced more bone formation to a greater extent (1.8 fold) than that of Col-gel. However, bone mineral density in both bones was equivalent, regardless of Thio-CS or Col-gel carrier. Taken together, Thio-CS system might be useful for delivering osteogenic protein BMP-2 and present a promising bone regeneration strategy.

Bae, In-Ho; Jeong, Byung-Chul; Kim, Sun-Hun; Koh, Jeong-Tae

2013-01-01

55

Evaluation of a thiolated chitosan scaffold for local delivery of BMP-2 for osteogenic differentiation and ectopic bone formation.  

PubMed

Thiolated chitosan (Thio-CS) is a well-established pharmaceutical excipient for drug delivery. However, its use as a scaffold for bone formation has not been investigated. The aim of this study was to evaluate the potential of Thio-CS in bone morphogenetic protein-2 (BMP-2) delivery and bone formation. In vitro study showed that BMP-2 interacted with the Thio-CS and did not affect the swelling behavior. The release kinetics of BMP-2 from the Thio-CS was slightly delayed (70%) within 7 days compared with that from collagen gel (Col-gel, 85%), which is widely used in BMP-2 delivery. The BMP-2 released from Thio-CS increased osteoblastic cell differentiation but did not show any cytotoxicity until 21 days. Analysis of the in vivo ectopic bone formation at 4 weeks of posttransplantation showed that use of Thio-CS for BMP-2 delivery induced more bone formation to a greater extent (1.8 fold) than that of Col-gel. However, bone mineral density in both bones was equivalent, regardless of Thio-CS or Col-gel carrier. Taken together, Thio-CS system might be useful for delivering osteogenic protein BMP-2 and present a promising bone regeneration strategy. PMID:24024213

Bae, In-Ho; Jeong, Byung-Chul; Kook, Min-Suk; Kim, Sun-Hun; Koh, Jeong-Tae

2013-08-20

56

CME shock warps coronal streamer - observation and MHD simulation  

Microsoft Academic Search

A fast (v >= 1000 km s-1) CME was observed on 14 January 2002, which was linked to an M4.4 long-duration flare event and a post-eruption loop system visible on, but partially occulted by, the SW limb. The fast expanding CME collided with a North-hemispheric helmet streamer, which was located above NOAA AR 9773 and was in 60° distance from

B. van der Holst; L. van Driel-Gesztelyi; S. Poedts

2002-01-01

57

Flare and CME Properties and Rates at Sunspot Minimum  

Microsoft Academic Search

The corona at solar minimum generally differs greatly from that during active times. We discuss the current Cycle 23\\/24 minimum from the point of view of the occurrence of flares and CMEs (coronal mass ejections). By comparison with the previous minimum, the flare\\/CME ratio diminished by almost an order of magnitude. This suggests that the environmental effect in flare\\/CME association

H. S. Hudson; Yan Li

2010-01-01

58

Flare and CME Properties and Rates at Sunspot Minimum  

NASA Astrophysics Data System (ADS)

The corona at solar minimum generally differs greatly from that during active times. We discuss the current Cycle 23/24 minimum from the point of view of the occurrence of flares and CMEs (coronal mass ejections). By comparison with the previous minimum, the flare/CME ratio diminished by almost an order of magnitude. This suggests that the environmental effect in flare/CME association differed in the sense that the Cycle 23/24 minimum corona was relatively easy to disrupt.

Hudson, H. S.; Li, Y.

2010-06-01

59

Local delivery of FTY720 accelerates cranial allograft incorporation and bone formation  

PubMed Central

Endogenous stem cell recruitment to the site of skeletal injury is key to enhanced osseous remodeling and neovascularization. To this end, this study utilized a novel bone allograft coating of poly(lactic-co-glycolic acid) (PLAGA) to sustain the release of FTY720, a selective agonist for sphingosine 1-phosphate (S1P) receptors, from calvarial allografts. Uncoated allografts, vehicle-coated, low dose FTY720 in PLAGA (1:200 w:w) and high dose FTY720 in PLAGA (1:40) were implanted into critical size calvarial bone defects. The ability of local FTY720 delivery to promote angiogenesis, maximize osteoinductivity and improve allograft incorporation by recruitment of bone progenitor cells from surrounding soft tissues and microcirculation was evaluated. FTY720 bioactivity after encapsulation and release was confirmed with sphingosine kinase 2 assays. HPLC-MS quantified about 50% loaded FTY720 release of the total encapsulated drug (4.5 µg) after 5 days. Following 2 weeks of defect healing, FTY720 delivery led to statistically significant increases in bone volumes compared to controls, with total bone volume increases for uncoated, coated, low FTY720 and high FTY720 of 5.98, 3.38, 7.2 and 8.9 mm3, respectively. The rate and extent of enhanced bone growth persisted through week 4 but, by week 8, increases in bone formation in FTY720 groups were no longer statistically significant. However, micro-computed tomography (microCT) of contrast enhanced vascular ingrowth (MICROFIL®) and histological analysis showed enhanced integration as well as directed bone growth in both high and low dose FTY720 groups compared to controls.

Huang, Cynthia; Das, Anusuya; Barker, Daniel; Tholpady, Sunil; Wang, Tiffany; Cui, Quanjun; Ogle, Roy

2012-01-01

60

Analysis of CME Trajectories using STEREO Heliospheric Imager Data  

NASA Astrophysics Data System (ADS)

We have previously demonstrated the determination of the 3D (velocity and direction) trajectory of CMEs using stereoscopic analysis of a series of simultaneous coronagraph image pairs from the STEREO A and B spacecraft. Here, we use these trajectory results, together with an analysis of the CME tracks as seen in STEREO’s Heliospheric Imagers, to study the propagation of CMEs beyond the coronagraph field-of-view. In particular, we want to use the Heliospheric Imager data to better understand when and why CME trajectories deviate from radial, constant velocity propagation beyond 0.1 AU. Because of the wide field-of-view of the imagers, if propagation is radial at a constant velocity, then there is a simple analytic relationship between the shape of a CME’s track in a elongation versus time plot (where elongation is the angle between the Sun and the CME front) and the direction and speed of the CME. We compare the track of the CME’s bright leading edge in the HI image with this analytic prediction using the speed and direction determined from the coronagraphs to study deviations from this constant-velocity, radial propagation assumption. Further analysis of the Heliospheric Imager data may also reveal the cause of any observed acceleration or deceleration. We will also describe the software developed for this analysis.

Liewer, P. C.; de Jong, E. M.; Hall, J. R.; Howard, R. A.; Thompson, W. T.

2009-12-01

61

CME Propagation Characteristics from Radio Observations  

NASA Astrophysics Data System (ADS)

We explore the relationship among three coronal mass ejections (CMEs), observed on 28 October 2003, 7 November 2004, and 20 January 2005, the type II burst-associated shock waves in the corona and solar wind, as well as the arrival of their related shock waves and magnetic clouds at 1 AU. Using six different coronal/interplanetary density models, we calculate the speeds of shocks from the frequency drifts observed in metric and decametric radio wave data. We compare these speeds with the velocity of the CMEs as observed in the plane-of-the-sky white-light observations and calculated with a cone model for the 7 November 2004 event. We then follow the propagation of the ejecta using Interplanetary Scintillation measurements, which were available for the 7 November 2004 and 20 January 2005 events. Finally, we calculate the travel time of the interplanetary shocks between the Sun and Earth and discuss the velocities obtained from the different data. This study highlights the difficulties in making velocity estimates that cover the full CME propagation time.

Pohjolainen, S.; van Driel-Gesztelyi, L.; Culhane, J. L.; Manoharan, P. K.; Elliott, H. A.

2007-08-01

62

CME Onset and Take-off  

NASA Astrophysics Data System (ADS)

For understanding and eventually predicting coronal mass ejections/eruptive flares, two critical questions must be answered: What is the mechanism for eruption onset, and what is the mechanism for the rapid acceleration? We address these questions in the context of the breakout model using 2.5D MHD simulations with adaptive mesh refinement (AMR). The AMR capability allowed us to achieve ultra-high numerical resolution and, thereby, determine the influence of the effective Lundquist number on the eruption. Our calculations show that, at least, for the breakout model, the onset of reconnection external to the highly-sheared filament channel is the onset mechanism. Once this reconnection turns on, eruption is inevitable. However, as long as this is the only reconnection in the system, the eruption remains slow. We find that the eruption undergoes an abrupt "take-off" when the flare reconnection below the erupting plasmoid develops significant reconnection jets. We conclude that in fast CMEs, flare reconnection is the primary mechanism responsible for both flare heating and CME acceleration. We discuss the implications of these results for SDO observations and describe possible tests of the model. This work was supported, in part, by the NASA TR&T and SR&T Programs.

Antiochos, Spiro K.; Karpen, J. T.; DeVore, C. R.

2011-05-01

63

Hinode, STEREO and SOHO obervations of a CME event  

NASA Astrophysics Data System (ADS)

Coronal Mass Ejections (CMEs) are among the most dramatic and violent dynamic events occurring in the solar atmosphere, and have significant impact on the near-Earth environment. So far, the physical processes responsible for their release and acceleration have not been completely understood, in part because of the lack of direct measurements of the CME plasma phycical parameters and evolution during the CME onset. Here we describe the analysis of multiwavelength observations from Hinode, SOHO and STEREO of the very early phases of a CME observed during the Whole Heliospheric Interval campaign. SECCHI/EUVI, SECCHI/COR1, SOHO/EIT and SOHO/LASCO images are used to reconstruct the 3D trajectory, velocity and acceleration up to 20 solar radii. Hinode/EIS, Hinode/XRT and SOHO/UVCS high resolution EUV spectra and X-ray images are used to measure the physical properties and the thermal structure of the core of the CME ejecta as a function of time up to 2.0 solar radii. The physical properties of the current sheet that formed after the CME erupted are also measured as a function of time.

Landi, E.; Raymond, J. C.; Miralles, M. P.; Hara, H.

2010-12-01

64

Making other earths: dynamical simulations of terrestrial planet formation and water delivery  

Microsoft Academic Search

We present results from 44 simulations of late stage planetary accretion, focusing on the delivery of volatiles (primarily water) to the terrestrial planets. Our simulations include both planetary “embryos” (defined as Moon to Mars sized protoplanets) and planetesimals, assuming that the embryos formed via oligarchic growth. We investigate volatile delivery as a function of Jupiter's mass, position and eccentricity, the

Sean N. Raymond; Thomas R. Quinn; Jonathan I. Lunine

2004-01-01

65

Oral delivery of bioencapsulated coagulation factor IX prevents inhibitor formation and fatal anaphylaxis in hemophilia B mice.  

PubMed

To address complications of pathogenic antibody or life-threatening anaphylactic reactions in protein replacement therapy for patients with hemophilia or other inherited protein deficiencies, we have developed a prophylactic protocol using a murine hemophilia B model. Oral delivery of coagulation factor IX fused with cholera toxin beta-subunit (with or without a furin cleavage site; CTB-FFIX or CTB-FIX), expressed in chloroplasts (up to 3.8% soluble protein or 0.4 mg/g leaf tissue), bioencapsulated in plant cells, effectively blocked formation of inhibitory antibodies (undetectable or up to 100-fold less than controls). Moreover, this treatment eliminated fatal anaphylactic reactions that occurred after four to six exposures to intravenous F.IX. Whereas only 20-25% of control animals survived after six to eight F.IX doses, 90-93% of F.IX-fed mice survived 12 injections without signs of allergy or anaphylaxis. Immunostaining confirmed delivery of F.IX to Peyer's patches in the ileum. Within 2-5 h, feeding of CTB-FFIX additionally resulted in systemic delivery of F.IX antigen. This high-responder strain of hemophilia B mice represents a new animal model to study anaphylactic reactions. The protocol was effective over a range of oral antigen doses (equivalent to 5-80 microg recombinant F.IX/kg), and controlled inhibitor formation and anaphylaxis long-term, up to 7 months (approximately 40% life span of this mouse strain). Oral antigen administration caused a deviant immune response that suppressed formation of IgE and inhibitory antibodies. This cost-effective and efficient approach of antigen delivery to the gut should be applicable to several genetic diseases that are prone to pathogenic antibody responses during treatment. PMID:20351275

Verma, Dheeraj; Moghimi, Babak; LoDuca, Paul A; Singh, Harminder D; Hoffman, Brad E; Herzog, Roland W; Daniell, Henry

2010-03-29

66

Obstetrician/Gynecologists and Postpartum Mental Health: Differences between CME Course Takers and Nontakers  

ERIC Educational Resources Information Center

|Introduction: Continuing medical education (CME) courses are an essential component of professional development. Research indicates a continued need for understanding how and why physicians select certain CME courses, as well as the differences between CME course takers and nontakers. Purpose: Obstetrician-gynecologists (OB-GYNs) are health care…

Leddy, Meaghan A.; Farrow, Victoria A.; Joseph, Gerald F., Jr.; Schulkin, Jay

2012-01-01

67

Initial-Condition Influences on CME Expansion and Propagation  

NASA Astrophysics Data System (ADS)

A general-purpose melon-seed-overpressure-expansion (MSOE) model is used to examine the dependence of the expansion and propagation of fast CMEs on average initial values of the magnetic field inside the CME, the magnetic field outside the CME, and the CME mass. The MSOE model extracts from the real situation only features that are essential in determining the expansion and propagation processes and idealizes them to obtain an adaptable “minimalist” set of equations that governs these processes yet retains enough relevant physics to give useful results. This minimalist set is used to carry out a systematic comparison of solutions against four sets of observed correlations between CME and ICME parameters in which the input parameters to the MSOE model are varied to achieve simultaneous fits to all four correlations. The fits impose relations between the three independent input variables: initial internal field strength, initial external field strength, and initial density. For example, light CMEs ( e.g., those with no prominences) require the external field strength to nearly equal the internal field strength. However, heavy CMEs ( e.g., those with prominences) require the external field strength to be much weaker than the internal field strength.

Siscoe, G. L.; Crooker, N. U.; Elliott, H. A.

2006-12-01

68

Autophagy and formation of tubulovesicular autophagosomes provide a barrier against nonviral gene delivery.  

PubMed

Cationic liposome (lipoplex) and polymer (polyplex)-based vectors have been developed for nonviral gene delivery. These vectors bind DNA and enter cells via endosomes, but intracellular transfer of DNA to the nucleus is inefficient. Here we show that lipoplex and polyplex vectors enter cells in endosomes, activate autophagy and generate tubulovesicular autophagosomes. Activation of autophagy was dependent on ATG5, resulting in lipidation of LC3, but did not require the PtdIns 3-kinase activity of PIK3C3/VPS34. The autophagosomes generated by lipoplex fused with each other, and with endosomes, resulting in the delivery of vectors to large tubulovesicular autophagosomes, which accumulated next to the nucleus. The tubulovesicular autophagosomes contained autophagy receptor protein SQSTM1/p62 and ubiquitin, suggesting capture of autophagy cargoes, but fusion with lysosomes was slow. Gene delivery and expression from both lipoplex and polyplex increased 8-fold in atg5 (-/-) cells unable to generate tubulovesicular autophagosomes. Activation of autophagy and capture within tubulovesicular autophagosomes therefore provides a new cellular barrier against efficient gene transfer and should be considered when designing efficient nonviral gene delivery vectors. PMID:23422759

Roberts, Rebecca; Al-Jamal, Wafa' T; Whelband, Matthew; Thomas, Paul; Jefferson, Matthew; van den Bossche, Jeroen; Powell, Penny P; Kostarelos, Kostas; Wileman, Thomas

2013-02-19

69

Transdermal Drug Delivery by Jet Injectors: Energetics of Jet Formation and Penetration  

Microsoft Academic Search

Purpose. Pressure-driven jets have been used for intradermal delivery of a variety of drugs. Despite their introduction into clinical medicine, variability and occasional bruising have limited their widespread acceptance. Although numerous clinical studies of jet injectors have been reported in the literature, surprisingly little is known about the mechanisms of jet penetration into the skin. In this article, we report

Joy Schramm; Samir Mitragotri

2002-01-01

70

Methods and apparatuses for reagent delivery, reactive barrier formation, and pest control  

DOEpatents

A reagent delivery method includes positioning reagent delivery tubes in contact with soil. The tubes can include a wall that is permeable to a soil-modifying reagent. The method further includes supplying the reagent in the tubes, diffusing the reagent through the permeable wall and into the soil, and chemically modifying a selected component of the soil using the reagent. The tubes can be in subsurface contact with soil, including groundwater, and can be placed with directional drilling equipment independent of groundwater well casings. The soil-modifying reagent includes a variety of gases, liquids, colloids, and adsorbents that may be reactive or non-reactive with soil components. The method may be used inter alia to form reactive barriers, control pests, and enhance soil nutrients for microbes and plants.

Gilmore, Tyler [Pasco, WA; Kaplan, Daniel I [Aiken, SC; Last, George [Richland, WA

2002-07-09

71

Stent-Based Delivery of Sirolimus Reduces Neointimal Formation in a Porcine Coronary Model  

Microsoft Academic Search

Background—The purpose of this study was to determine the efficacy of stent-based delivery of sirolimus (SRL) alone or in combination with dexamethasone (DEX) to reduce in-stent neointimal hyperplasia. SRL is a potent immunosup- pressive agent that inhibits SMC proliferation by blocking cell cycle progression. Methods and Results—Stents were coated with a nonerodable polymer containing 185 mg SRL, 350 mg DEX,

Takeshi Suzuki; Greg Kopia; Shin-ichiro Hayashi; Lynn R. Bailey; Gerard Llanos; Robert Wilensky; Bruce D. Klugherz; George Papandreou; Pallassana Narayan; Martin B. Leon; Alan C. Yeung; Fermin Tio; Philip S. Tsao; Robert Falotico; Andrew J. Carter

72

The television, school, and family project. V. The impact of curriculum delivery format on program acceptance.  

PubMed

Social psychological interventions have been successful in preventing drug and tobacco use in adolescents, but target audience involvement has not been well documented. Examination of program acceptance is necessary to avoid ambiguity when interpreting findings within and across studies. This report presents results from a program acceptance study of a seventh-grade smoking/drug-use prevention and cessation field trial. The research design is an assessment of two experimentally manipulated variations in program delivery on the program acceptance of all provider and target groups involved. Experimental manipulations included classroom and mass broadcast television demonstrations of social resistance skills against pressures to smoke and use drugs. Three aspects of target audience program acceptance were assessed: participation, satisfaction, and perceived program efficacy. Respondents included the target audience (seventh-grade students and parents), instructors, classroom observers, and school administrative staff. Strong main effects of television delivery on student and parent participation were observed. The findings suggest the usefulness of student homework assignment to view television segments with parents at home as a strategy to achieve family involvement in school-based programs. Both television and classroom delivery separately demonstrated significant positive effects on overall program acceptance with moderate interactive effects on perceived program efficacy. While classroom teacher/observers and school administrators reported strong preferences for the experimental (social resistance) classroom curriculum, acceptance of experimental and comparison (information-based) curricula by the student/parent target audience was equivalent. PMID:2798371

Brannon, B R; Dent, C W; Flay, B R; Smith, G; Sussman, S; Pentz, M A; Johnson, C A; Hansen, W B

1989-07-01

73

Three-Dimensional CME Reconstruction Using Geometric and Polarimetric Localization  

NASA Astrophysics Data System (ADS)

The geometric localization technique [Pizzo and Biesecker, 2004] utilizes a series of lines-of-sight from two space-based coronagraphs to determine gross propagation characteristics of coronal mass ejections (CMEs) in three-dimensional space. The polarimetric localization technique [Moran and Davila, 2004] uses the percent polarization observed by a single coronagraph to obtain a three-dimensional reconstruction of a CME. We apply both techniques to STEREO/SECCHI/COR2 data to determine the speed and direction of propagation, as well as the size, shape, and orientation of some recent CMEs, including the event of 3 April 2010. The results obtained from this analysis can be used as inputs to the numerical MHD code, Enlil, which will track the evolution of the CME and its interaction with the solar wind.

de Koning, C. A.; Pizzo, V. J.

2010-12-01

74

The effect of Rho kinase inhibition on capsule formation using local delivery of Y-27632  

Microsoft Academic Search

Introduction. Despite current developments in surgery and manufacturing technology, capsular contracture is still the most common late complication associated with breast implant surgery. This proposed study was designed to investigate the effect of Rho kinase inhibition on capsule formation. Rho kinases are pivotal regulators of several aspects of cell behavior and contribute to reorganization of the actin cytoskeleton, formation of

S. Totan; E. Yuksel; A. Amer; M. Spira

2004-01-01

75

Spectroscopic Detection of Turbulence in Post-CME Current Sheets  

NASA Astrophysics Data System (ADS)

Plasma in post-CME current sheets (CSs) is expected to be highly turbulent because of the tearing and coalescence instability and/or local microscopic instabilities. For this reason, in the last decade the inconsistency between the observed (~104-105 km) and the expected (~1-10 m) CS thickness has been tentatively explained in many MHD models as a consequence of plasma turbulence that should be able to significantly broaden the CS. However, from the observational point of view, little is known about this subject. A few post-CME CSs have been observed in UVCS spectra as a strong emission in the high-temperature [Fe XVIII] line, usually unobservable in the solar corona. In this work, published data on post-CME CSs observed by UVCS are reanalyzed, concentrating for the first time on the evolution of turbulence derived from the nonthermal broadening of the [Fe XVIII] line profiles. Derived turbulent speeds are on the order of ~60 km s-1 a few hours after the CME and slowly decay down to ~30 km s-1 in the following 2 days. From this evolution the anomalous diffusivity due to microinstabilities has been estimated, and the scenario of multiple small-scale reconnections is tested. Results show that the existence of many (~10-11 to 10-17 ?CS m-3) microscopic CSs (?CSs) of small sizes (~10-104 m) could explain not only the high CS temperatures but also the much larger observed thickness of macroscopic CSs, thanks to turbulent broadening.

Bemporad, A.

2008-12-01

76

Speed of Compression of Magnetosphere by CME Clouds  

NASA Astrophysics Data System (ADS)

The multi-point Cluster observations provide the opportunity to study the speed of compression of the magnetosphere at the impact of extreme solar events such as CMEs. The four-point Cluster FGM (high resolution), CIS and PEACE data during the passage of 17 CME clouds during 2001-2005, together with models of magnetosphere and magnetopause, are used to obtain the speed of compression of the dayside magnetosphere. The study shows that the speed of compression (within three seconds of impact) increases with the dynamic pressure of the CMEs, and that this speed exceeds the speed of the CMEs in some (five) cases (suggesting impulsive response) when the dynamic pressure of the CMEs exceed about 20 nPa. The magnetosphere is also found to undergo damped oscillations for about two minutes after the impact of some extreme CMEs (24 October 2003 and 29 October 2003) until the magnetic pressure outside and inside the magnetopause balances. The speed of compression is also found to increase with the negative IMF Bz of the CME suggesting that part of the compression is due to CME pressure and another part is due to magnetic reconnection. The plasma data (PEACE and CIS), though of low resolution (4 seconds), are being analysed to check if the magnetic field and plasma move together or do they undergo differential motion (important for magnetic field-plasma interactions at short time scales).

Nanan, B.; Alleyne, H.; Walker, S.; Lucek, E.; Reme, H.; Fazakerley, A.

2007-12-01

77

The June 1st 2008 CME in the Interplanetary Medium  

NASA Astrophysics Data System (ADS)

In this work we present a combined study/analysis of the counterpart of the CME of June 1st of 2008 in the interplanetary medium. This event has been largely studied because of its peculiar initiation and its possible forecasting consequences for space weather. We show an in situ analysis of the CME in the interplanetary medium in order to shed some light on the propagation and evolution mechanisms of the ICME. The energetic particles play an important role in order to understand the overall event, the source on the Sun and the effect over the Earth. The typical shock associated characteristics with the counterpart of the CMEs in the interplanetary medium has been determined, in order to understand the propagation properties. The magnetic cloud has been studied and analyzed using non force-free models as start point to incorporate expansion. To accomplish this analysis the IMPACT/STEREO B in-situ measurement have been considered in order to characterize the Interplanetary CME.

Nieves-Chinchilla, T.; F.-Vinas, A.; Gomez-Herrero, R.; Malandraki, O. E.; Dresing, N.; Hidalgo, M. A.; Davila, J.

2010-05-01

78

Type II Radio Bursts as an Indicator of CME Location  

NASA Astrophysics Data System (ADS)

We examined a subset of nine low-frequency radio events with type II radio bursts that drifted below 2 megahertz and were detected by the WAVES investigation on the WIND spacecraft. For each event, we identified the associated coronal mass ejection (CME) and derived the electron density using a model of solar wind plasma frequency (fp ? 9 * ne1/2, where fp is plasma frequency in kHz and ne is electron density in cm-3) . We also used the pb_inverter program in SolarSoft developed by Howard and Hayes to examine the electron density structure. Expanding on the Van De Hulst process of inverting polarized brightness measurements, the program inverts total brightness measurements from SOHO LASCO images to extract electron density information. From the electron density inferred from radio spectra, we derived the location of the CME using five standard electron density to height models (Leblanc, 1996; Saito, 1977; Bougeret, 1984; Alvarez, 1973; and Fainberg, 1971). Using images from the LASCO instrument on SOHO and the SECCHI instrument on STEREO, we extracted locations of the leading edge of the CME and compared the heights and velocities to those found using the frequency data. For the lowest frequency events, we also compared our results to the outputs of ENLIL, a time-dependent, three-dimensional, MHD model of the heliosphere hosted by the Community Coordinated Modeling Center (CCMC) at NASA Goddard Space Flight Center.

Quirk, C. A.; St Cyr, O. C.; Henning, C.; Xie, H.; Gilbert, H. R.; Orlove, M.; Gopalswamy, N.; Odstrcil, D.

2011-12-01

79

Suppression of FVIII Inhibitor Formation in Hemophilic Mice by Delivery of Transgene Modified Apoptotic Fibroblasts  

PubMed Central

The development of inhibitory antibodies to factor VIII (FVIII) is currently the most significant complication of FVIII replacement therapy in the management of patients with severe hemophilia A. Immune tolerance protocols for the eradication of inhibitors require daily delivery of intravenous FVIII for at least 6 months and are unsuccessful in 20–40% of treated patients. We hypothesize that tolerance can be induced more efficiently and reliably by delivery of FVIII antigen within autologous apoptotic cells (ACs). In this study, we demonstrated suppression of the T cell and inhibitor responses to FVIII by infusion of FVIII expression vector modified apoptotic syngeneic fibroblasts in both naive and preimmunized hemophilia A mice. ACs without FVIII antigen exerted modest generalized immune suppression mediated by anti-inflammatory signals. However, FVIII expressing apoptotic syngeneic fibroblasts produced much stronger antigen-specific immune suppression. Mice treated with these fibroblasts generated CD4+ T cells that suppressed the immune response to FVIII after adoptive transfer into naive recipients and antigen-specific CD4+CD25+ regulatory T cells (Tregs) that inhibited the proliferation of FVIII responsive effector T cells in vitro. These preclinical results demonstrate the potential for using FVIII vector modified autologous ACs to treat high-titer inhibitors in patients with hemophilia A.

Su, Rui-Jun; Epp, Angela; Latchman, Yvette; Bolgiano, Doug; Pipe, Steven W; Josephson, Neil C

2009-01-01

80

Hierarchical formation of supramolecular transient networks in water: a modular injectable delivery system.  

PubMed

A modular one-component supramolecular transient network in water, based on poly(ethylene glycol) and end-capped with four-fold hydrogen bonding units, is reported. Due to its nonlinear structural formation, this system allows active proteins to be added to the hydrogel during formation. Once implanted in vivo it releases the protein by erosion of both the protein and polymer via dissolution. PMID:22528786

Dankers, Patricia Y W; Hermans, Thomas M; Baughman, Travis W; Kamikawa, Yuko; Kieltyka, Roxanne E; Bastings, Maartje M C; Janssen, Henk M; Sommerdijk, Nico A J M; Larsen, Antje; van Luyn, Marja J A; Bosman, Anton W; Popa, Eliane R; Fytas, George; Meijer, E W

2012-04-23

81

STUDY OF THE 2007 APRIL 20 CME-COMET INTERACTION EVENT WITH AN MHD MODEL  

SciTech Connect

This study examines the tail disconnection event on 2007 April 20 on comet 2P/Encke, caused by a coronal mass ejection (CME) at a heliocentric distance of 0.34 AU. During their interaction, both the CME and the comet are visible with high temporal and spatial resolution by the STEREO-A spacecraft. Previously, only current sheets or shocks have been accepted as possible reasons for comet tail disconnections, so it is puzzling that the CME caused this event. The MHD simulation presented in this work reproduces the interaction process and demonstrates how the CME triggered a tail disconnection in the April 20 event. It is found that the CME disturbs the comet with a combination of a 180 deg. sudden rotation of the interplanetary magnetic field (IMF), followed by a 90 deg. gradual rotation. Such an interpretation applies our understanding of solar wind-comet interactions to determine the in situ IMF orientation of the CME encountering Encke.

Jia, Y. D.; Russell, C. T.; Jian, L. K. [IGPP, University of California, Los Angeles, CA 90095 (United States); Manchester, W. B.; Cohen, O.; Hansen, K. C.; Combi, M. R.; Gombosi, T. I. [CSEM, University of Michigan, Ann Arbor, MI, 48109 (United States); Vourlidas, A. [Solar Physics Branch, Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2009-05-01

82

Crystal Structure of the Transcriptional Regulator CmeR From Campylobacter Jejuni  

SciTech Connect

The CmeABC multidrug efflux pump, which belongs to the resistance-nodulation-division (RND) family, recognizes and extrudes a broad range of antimicrobial agents and is essential for Campylobacter jejuni colonization of the animal intestinal tract by mediating the efflux of bile acids. The expression of CmeABC is controlled by the transcriptional regulator CmeR, whose open reading frame is located immediately upstream of the cmeABC operon. To understand the structural basis of CmeR regulation, we have determined the crystal structure of CmeR to 2.2 {angstrom} resolution, revealing a dimeric two-domain molecule with an entirely helical architecture similar to members of the TetR family of transcriptional regulators. Unlike the rest of the TetR regulators, CmeR has a large center-to-center distance (54 {angstrom}) between two N termini of the dimer, and a large flexible ligand-binding pocket in the C-terminal domain. Each monomer forms a 20 {angstrom} long tunnel-like cavity in the ligand-binding domain of CmeR and is occupied by a fortuitous ligand that is identified as glycerol. The binding of glycerol to CmeR induces a conformational state that is incompatible with target DNA. As glycerol has a chemical structure similar to that of potential ligands of CmeR, the structure obtained mimics the induced form of CmeR. These findings reveal novel structural features of a TetR family regulator, and provide new insight into the mechanisms of ligand binding and CmeR regulation.

Gu, R.; Su, C.-C.; Shi, F.; McDermott, G.; Zhang, Q.; Yu, E.W.

2009-06-01

83

Crystal Structure of the Transcriptional Regulator CmeR from Campylobacter jejuni  

PubMed Central

The CmeABC multidrug efflux pump, which belongs to the resistance-nodulation-division (RND) family, recognizes and extrudes a broad range of antimicrobial agents and is essential for Campylobacter jejuni colonization of the animal intestinal tract by mediating the efflux of bile acids. The expression of CmeABC is controlled by the transcriptional regulator CmeR, whose open reading frame is located immediately upstream of the cmeABC operon. To understand the structural basis of CmeR regulation, we have determined the crystal structure of CmeR to 2.2 Å resolution, revealing a dimeric two-domain molecule with an entirely helical architecture similar to members of the TetR family of transcriptional regulators. Unlike the rest of the TetR regulators, CmeR has a large center-to-center distance (54 Å) between two N termini of the dimer, and a large flexible ligand-binding pocket in the C-terminal domain. Each monomer forms a 20 Å long tunnel-like cavity in the ligand-binding domain of CmeR and is occupied by a fortuitous ligand that is identified as glycerol. The binding of glycerol to CmeR induces a conformational state that is incompatible with target DNA. As glycerol has a chemical structure similar to that of potential ligands of CmeR, the structure obtained mimics the induced form of CmeR. These findings reveal novel structural features of a TetR family regulator, and provide new insight into the mechanisms of ligand binding and CmeR regulation.

Gu, Ruoyu; Su, Chih-Chia; Shi, Feng; Li, Ming; McDermott, Gerry; Zhang, Qijing; Yu, Edward W.

2007-01-01

84

Synthetic radio maps of CME-driven shocks below 4 solar radii heliocentric distance  

Microsoft Academic Search

We present 2 1\\/2 D numerical MagnetoHydroDynamic (MHD) simulations of coronal mass ejections (CMEs) in conjunction with plasma simulations of radio emission from the CME-driven shocks. The CME-driven shock extends to an almost spherical shape during the temporal evolution of the CME. Our plasma simulations can reproduce the dynamic spectra of coronal type II radio bursts, with the frequency drift

J. M. Schmidt; N. Gopalswamy

2008-01-01

85

Analyzing Reasons for Non-Adoption of Distance Delivery Formats in Occupational Therapy Assistant (OTA) Education  

ERIC Educational Resources Information Center

|Though distance education formats could help address an urgent need for growth in the occupational therapy assistant (OTA) workforce, distance methods are not as accepted in these programs as they are in other professional and clinical programs. This study investigated whether beliefs and levels of experience of OTA program directors shaped their…

Gergen, Theresa; Roblyer, M. D.

2013-01-01

86

Drug delivery options for the treatment of ocular inflammation.  

PubMed

Treatments available for ocular inflammatory diseases and their associated complications have expanded significantly over the course of the last ten years. While corticosteroids are a mainstay of therapy for uveitis and macular edema, the methods of delivering corticosteroids have evolved. Intravitreal triamcinolone acetonide provides a local therapy for persistent cystoid macular edema (CME) and posterior uveitis. Other intravitreal therapies, such as bevacizumab and methotrexate, have also been used successfully in uveitic CME. Sustained release intravitreal implants, including the fluocinolone acetonide implant and the dexamethasone drug delivery system, offer an alternative therapy for chronic, recalcitrant posterior uveitis and CME. Their design was inspired by the ganciclovir implant, which prevented the progression of CMV retinitis in AIDS patients. Technological advances in drug delivery have supplied new treatments for patients with ocular inflammatory disease. PMID:21091013

Lobo, Ann-Marie; Sobrin, Lucia; Papaliodis, George N

87

Non-antibiotic treatment recommendations: delivery formats and implications for parent resistance  

Microsoft Academic Search

This study draws on a database of 570 community-based acute pediatric encounters in the USA and uses conversation analysis as a methodology to identify two formats physicians use to recommend non-antibiotic treatment in acute pediatric care (using a subset of 309 cases): recommendations for particular treatment (e.g., “I’m gonna give her some cough medicine.”) and recommendations against particular treatment (e.g.,

Tanya Stivers

2005-01-01

88

M5.3 Labor Day Solar Flare-CME  

NASA Video Gallery

At 9:35 PM ET on September 5, 2011, the sun emitted an Earth-directed M5.3 class flare as measured by the GOES satellite. The flare erupted from a region of the sun that appears close to dead center from Earth's perspective, an active region designated number 1283. A coronal mass ejection (CME) was associated with this flare and is a relatively slow one, traveling at under 200 miles per second. This extreme close-up video was taken by the Solar Dynamics Observatory in 171 angstrom.

Holly Zell

2011-09-06

89

Relationship between multiple type II solar radio bursts and CME observed by STEREO/SECCHI  

NASA Astrophysics Data System (ADS)

Aims: Two or more type II bursts are occasionally observed in close time sequence during solar eruptions, which are known as multiple type II bursts. The origin of the successive burst has been interpreted in terms of coronal mass ejections (CMEs) and/or flares. Detailed investigations of the relationship between CMEs and the bursts enable us to understand the nature of the multiple type II bursts. In this study, we examine multiple type II bursts and compare their kinematics with those of a CME occurring near the time of the bursts. Methods: To do this, we selected multiple type II bursts observed by the Culgoora radiospectrographs and a limb CME detected in the low corona field of view (1.4-4 Rs) of a STEREO/SECCHI instrument on December 31, 2007. To determine the 3D kinematics of the CME, we applied the stereoscopic technique to the STEREO/SECCHI data. Results: Our main results are as follows: (1) the multiple type II bursts occurred successively at ten minute intervals and displayed various emission structures and frequency drifting rates; (2) near the time of the bursts, the CME was observed by STEREO and SOHO simultaneously, but no evidence of other CMEs was detected; (3) inspection of the 3D kinematics of the CME using the stereoscopic observation by STEREO/SECCHI revealed that the CME propagated along the eastward radial direction as viewed from the Earth; (4) very close time and height associations were found between the CME nose and the first type II burst, and between CME-streamer interaction and the second type II burst. Conclusions: On the basis of these results, we suggest that a single shock in the leading edge of the CME could be the source of the multiple type II bursts and support the notion that the CME nose and the CME-streamer interaction are the two main mechanisms able to generate the bursts.

Cho, K.-S.; Bong, S.-C.; Moon, Y.-J.; Shanmugaraju, A.; Kwon, R.-Y.; Park, Y. D.

2011-06-01

90

Nanosized hydroxyapatite and other calcium phosphates: chemistry of formation and application as drug and gene delivery agents.  

PubMed

The first part of this review looks at the fundamental properties of hydroxyapatite (HAP), the basic mineral constituent of mammalian hard tissues, including the physicochemical features that govern its formation by precipitation. A special emphasis is placed on the analysis of qualities of different methods of synthesis and of the phase transformations intrinsic to the formation of HAP following precipitation from aqueous solutions. This serves as an introduction to the second part and the main subject of this review, which relates to the discourse regarding the prospects of fabrication of ultrafine, nanosized particles based on calcium phosphate carriers with various therapeutic and/or diagnostic agents coated on and/or encapsulated within the particles. It is said that the particles could be either surface-functionalized with amphiphiles, peptides, proteins, or nucleic acids or injected with therapeutic agents, magnetic ions, or fluorescent molecules. Depending on the additive, they could be subsequently used for a variety of applications, including the controlled delivery and release of therapeutic agents (extracellularly or intracellularly), magnetic resonance imaging and hyperthermia therapy, cell separation, blood detoxification, peptide or oligonucleotide chromatography and ultrasensitive detection of biomolecules, and in vivo and in vitro gene transfection. Calcium phosphate nanoparticles as carriers of therapeutic agents that would enable a controlled drug release to treat a given bone infection and at the same be resorbed in the body so as to regenerate hard tissue lost to disease are emphasized hereby as one of the potentially attractive smart materials for the modern medicine. PMID:21061364

Uskokovi?, Vuk; Uskokovi?, Dragan P

2011-01-01

91

Exercise Motivation of College Students in Online, Face-to-Face, and Blended Basic Studies Physical Activity and Wellness Course Delivery Formats  

ERIC Educational Resources Information Center

Objective: The purpose of this study was to assess exercise motivation among college students self-selected into 4 online (OL) and face-to-face (F2F) basic studies' physical activity and wellness course delivery formats. Participants/Methods: Out of 1,037 enrolled students during the Spring 2009 semester, 602 responded online to demographic…

Sidman, Cara Lynn; Fiala, Kelly Ann; D'Abundo, Michelle Lee

2011-01-01

92

Effects of local delivery of trapidil on neointima formation in a rabbit angioplasty model.  

PubMed

1. Smooth muscle cell (SMC) proliferation can result in luminal reduction of a vessel following balloon angioplasty. This study was designed (i) to determine if local administration of trapidil (triazolopyrimidine) into a vessel wall reduces neointima formation, and (ii) to explore the mechanism involved in the subsequent reduction in cell proliferation. 2. Following balloon angioplasty in 40 anaesthetized New Zealand White rabbits, trapidil (50-200 mg) or its vehicle (saline) was injected into the dilated vessel wall of the right femoral artery. Experimental groups and time of investigation: (I) vehicle (2 weeks, n = 3), (II) trapidil-100 mg (2 weeks, n = 3), (III) vehicle (3 weeks, n = 8), (IV) trapidil-50 mg (3 weeks, n = 5); (V) trapidil-100 mg (3 weeks, n = 9) or (V) trapidil-200 mg (3 weeks, n = 7). 3. After 2 weeks, there was a significant reduction of intimal hyperplasia (expressed as intima to media area ratio) in the trapidil group compared with vehicle (0.44 +/- 0.04 vs 0.93 +/- 0.04, *P < 0.05) and also a significant reduction in cell proliferation (% ratio of BrdU-positive cells to total cell number: vehicle 14 +/- 2% vs trapidil 6 +/- 1%, *P < 0.05). 4. After 3 weeks, there was a dose-dependent reduction of intimal hyperplasia in the trapidil groups compared with vehicle (trapidil 50 mg 1.14 +/- 0.04; trapidil 100 mg 0.91 +/- 0.09*; trapidil 200 mg 0.77 +/- 0.09* vs vehicle 1.67 +/- 0.23, *P < 0.05). 5. Thus, the local administration of trapidil to the rabbit femoral artery reduces the neointima formation, which occurs 2 or 3 weeks after balloon angioplasty via a mechanism, which is dependent on inhibition of cell proliferation. PMID:10711356

Zacharowski, K; Schneidmüller, D; Ibe, W; Grosser, T; Buerke, M; Meyer, J; Darius, H

2000-02-01

93

Effects of local delivery of trapidil on neointima formation in a rabbit angioplasty model  

PubMed Central

Smooth muscle cell (SMC) proliferation can result in luminal reduction of a vessel following balloon angioplasty. This study was designed (i) to determine if local administration of trapidil (triazolopyrimidine) into a vessel wall reduces neointima formation, and (ii) to explore the mechanism involved in the subsequent reduction in cell proliferation. Following balloon angioplasty in 40 anaesthetized New Zealand White rabbits, trapidil (50–200?mg) or its vehicle (saline) was injected into the dilated vessel wall of the right femoral artery. Experimental groups and time of investigation: (I) vehicle (2 weeks, n=3), (II) trapidil-100?mg (2 weeks, n=3), (III) vehicle (3 weeks, n=8), (IV) trapidil-50?mg (3 weeks, n=5); (V) trapidil-100?mg (3 weeks, n=9) or (V) trapidil-200?mg (3 weeks, n=7). After 2 weeks, there was a significant reduction of intimal hyperplasia (expressed as intima to media area ratio) in the trapidil group compared with vehicle (0.44±0.04 vs 0.93±0.04, *P<0.05) and also a significant reduction in cell proliferation (% ratio of BrdU-positive cells to total cell number: vehicle 14±2% vs trapidil 6±1%, *P<0.05). After 3 weeks, there was a dose-dependent reduction of intimal hyperplasia in the trapidil groups compared with vehicle (trapidil 50?mg 1.14±0.04; trapidil 100?mg 0.91±0.09*; trapidil 200?mg 0.77±0.09* vs vehicle 1.67±0.23, *P<0.05). Thus, the local administration of trapidil to the rabbit femoral artery reduces the neointima formation, which occurs 2 or 3 weeks after balloon angioplasty via a mechanism, which is dependent on inhibition of cell proliferation.

Zacharowski, Kai; Schneidmuller, Dorien; Ibe, Waltraut; Grosser, Tilo; Buerke, Michael; Meyer, Jurgen; Darius, Harald

2000-01-01

94

Post-CME Reconnection and the Generation of Descending Solar Coronal Voids  

Microsoft Academic Search

Observations of solar coronal flares occurring behind coronal mass ejections (CME's) have shown downflowing voids in the corona, which are believed to be the signatures of descending magnetic flux tubes. We are studying the hypothesis that these flux tubes have reconnected in the current sheet which forms behind the CME in the high corona. We will present three dimensional MHD

Mark Linton; D. Longcope; H. Warren

2007-01-01

95

Creating a New Paradigm for CME: Seizing Opportunities within the Health Care Revolution.  

ERIC Educational Resources Information Center

|Forces creating change in continuing medical education (CME) are health care reform, quality management, information expansion, and technological advances. Opportunities are emerging in six areas: emphasis on learning, clinically relevant data, combination of quality management and CME, collaborative learning systems, focus on patient outcomes,…

Moore, Donald E., Jr.; And Others

1994-01-01

96

Promoting Free Online CME for Intimate Partner Violence: What Works at What Cost?  

ERIC Educational Resources Information Center

|Introduction: There is a need to provide practicing physicians with training on the recognition and management of intimate partner violence (IPV). Online continuing medical education (CME) could help meet this need, but there is little information on the costs and effectiveness of promoting online CME to physicians. This lack of information may…

Harris, John M., Jr.; Novalis-Marine, Cheryl; Amend, Robert W.; Surprenant, Zita J.

2009-01-01

97

An empirical model for prediction of geomagnetic storms using initially observed CME parameters at the Sun  

Microsoft Academic Search

In this study, we discuss the general behaviors of geomagnetic storm strength associated with observed parameters of coronal mass ejection (CME) such as speed (V) and earthward direction (D) of CMEs as well as the longitude (L) and magnetic field orientation (M) of overlaying potential fields of the CME source region, and we develop an empirical model to predict geomagnetic

R.-S. Kim; K.-S. Cho; Y.-J. Moon; M. Dryer; J. Lee; Y. Yi; K.-H. Kim; H. Wang; Y.-D. Park; Yong Ha Kim

2010-01-01

98

Kelvin-Helmholtz Instability of the CME Reconnection Outflow Layer in the Low Corona  

NASA Astrophysics Data System (ADS)

New capabilities for studying the Sun allow us to image for the first time the magnetic Kelvin-Helmholtz (KH) instability developing at the surface of a fast coronal mass ejecta (CME) less than 150 Mm above the solar surface. We conduct a detailed observational investigation of this phenomenon, observed off the east solar limb on 2010 November 3, in the EUV with SDO/AIA. In conjunction with STEREO-B/EUVI, we derive the CME source surface position. We ascertain the timing and early evolution of the CME outflow leading to the instability onset. We perform image and spectral analysis, exploring the CME plasma structuring and its parabolic flow pattern. As we evaluate and validate the consistency of the observations with theoretical considerations and predictions, we take the view that the ejecta layer corresponds to a reconnection outflow layer surrounding the erupting flux rope, accounting for the timing, high temperature (~11.6 MK), and high flow shear (~680 km s-1) on the unstable CME northern flank and for the observed asymmetry between the CME flanks. From the irregular evolution of the CME flow pattern, we infer a shear gradient consistent with expected spatial flow variations across the KH-unstable flank. The KH phenomenon observed is tied to the first stage of a linked flare-CME event.

Foullon, Claire; Verwichte, Erwin; Nykyri, Katariina; Aschwanden, Markus J.; Hannah, Iain G.

2013-04-01

99

Controlling Quality in CME/CPD by Measuring and Illuminating Bias  

ERIC Educational Resources Information Center

|Introduction: There has been a surge of interest in the area of bias in industry-supported continuing medical education/continuing professional development (CME/CPD) activities. In 2007, we published our first study on measuring bias in CME, demonstrating that our assessment tool was valid and reliable. In light of the increasing interest in this…

Dixon, David; Takhar, Jatinder; Macnab, Jennifer; Eadie, Jason; Lockyer, Jocelyn; Stenerson, Heather; Francois, Jose; Bell, Mary; Monette, Celine; Campbell, Craig; Marlow, Bernie

2011-01-01

100

CmeR Functions as a Pleiotropic Regulator and Is Required for Optimal Colonization of Campylobacter jejuni In Vivo  

Microsoft Academic Search

CmeR functions as a transcriptional repressor modulating the expression of the multidrug efflux pump CmeABC in Campylobacter jejuni. To determine if CmeR also regulates other genes in C. jejuni, we compared the transcriptome of the cmeR mutant with that of the wild-type strain using a DNA microarray. This comparison identified 28 genes that showed a >2-fold change in expression in

Baoqing Guo; Ying Wang; Feng Shi; Yi-Wen Barton; Paul Plummer; Donald L. Reynolds; Dan Nettleton; Tara Grinnage-Pulley; Jun Lin; Qijing Zhang

2008-01-01

101

Magnetospheric, Ionospheric, and Thermospheric Results for the May 1-4, 1998 CME Using a Coupled Sun to Earth Model  

Microsoft Academic Search

We present results from the Comprehensive Space Environment Model for the May 1-4, 1998 coronal mass ejection (CME). This CME is launched from the Sun and driven through a realistic magnetogram driven heliosphere. We present results of the CME encounter with the near-Earth space environment, including the magnetosphere, ionosphere, and thermosphere (MIT). We have run the simulation in two ways:

A. J. Ridley; W. Manchester; I. Roussev; T. Gombosi

2003-01-01

102

Colon-specific delivery of 5-fluorouracil from zinc pectinate pellets through in situ intracapsular ethylcellulose-pectin plug formation.  

PubMed

Conventional fluid-bed and immersion film coating of hydrophilic zinc pectinate pellets by hydrophobic ethylcellulose is met with fast drug release. This study explored in situ intracapsular pellet coating for colon-specific delivery of 5-fluorouracil (5-FU). The solid coating powder constituted ethylcellulose and pectin in weight ratios of 11:0 to 2:9. Its weight ratio to pellets varied between 2:3 and 3:2. Pectin was used as excipient of core pellets and coating powder in view of its potential use in colon cancer treatment. Delayed 5-FU release and core pectin dissolution were attainable when the weight ratio of solid coating powder to pellets was kept at 3:2, and weight ratio of ethylcellulose and pectin in coating powder was kept at 8:3 with particle size of ethylcellulose reduced to 22 ?m. In situ intracapsular wetting of pectin coat by dissolution medium resulted in the formation of ethylcellulose plug interconnecting with pellets through the binding action of pectin. Less than 25% of drug was released at the upper gastrointestinal tract. The majority of drug was released upon prolonged dissolution and in response to colonic enzyme pectinase, which digested core pellets. PMID:23225084

Elyagoby, A; Layas, N; Wong, T W

2012-12-05

103

E-learning for occupational physicians' CME: a study case.  

PubMed

The present study reports the results of the evaluation of an e-learning CME course in the field of Occupational Medicine. In particular the following aspects have been investigated: If and how the course contents have met the educational users' needs; The effectiveness of the course in terms of knowledge improvement; Users' behaviour. Attendance data and results of a sample of 1128 attendees have been analyzed via ad hoc developed tools for direct inspection of Moodle CMS database. The results document the effectiveness of the e-learning course, as regards meeting the educational needs of physicians and also the improvement in terms of knowledge and problem solving skill acquisition. Users' behaviour has revealed a certain tendency for passing the tests, more than for pursuing the best possible result. Interaction with the tutor is low. PMID:21685595

Mazzoleni, M Cristina; Rognoni, Carla; Finozzi, Enrico; Gri, Tommaso; Pagani, Marco; Imbriani, Marcello

2011-01-01

104

Jan. 19, 2012 - M3.2 Solar Flare and CME  

NASA Video Gallery

Our increasing active sun let loose a long duration M3.2 class flare and coronal mass ejection (CME) between 15:15 and 16:30 UT today. The CME is Earth directed with impact predicted for Jan. 21, 2012. This video taken by the Solar Dynamics Observatory, shows a close-up of sunspot 1401 region as the flare erupts. The CME cloud lifting off is visible just past midway in the video. Across the top is a graph of corresponding X-ray measurements taken by the GOES 15 satellite.

Holly Zell

2012-01-19

105

Assessing Educational Needs in Medical Practice: Guidelines for the CME Planning Committee Member  

PubMed Central

The most relevant and effective continuing medical education activities are those which address carefully identified and prioritized learning needs. As a consequence, discussions and activities of CME planning committees frequently focus upon the identification and assessment of physicians' educational needs. The physicians who serve as representatives of learners on such committees are often new to the planning, educational terms, approaches, and techniques. The basic ideas, definitions and concepts outlined in this paper are given as guidelines for physicians who are not experienced in formal CME planning. These guidelines should enhance the effectiveness of a physician's participation in CME planning committee activities.

Jennett, P. A.; Laxdal, O. E.

1984-01-01

106

Phase Relationships Between the CME-Energy Cycle, the Sunspot-Area Cycle and the Flare-Index Cycle  

NASA Astrophysics Data System (ADS)

We study the phase relationships between the coronal-mass-ejection (CME) energy cycle, the sunspot-area cycle, and the flare-index cycle from 1996 to 2010. The results show the following: i) The activity cycle of the flare index significantly leads the activity cycle of the sunspot area. ii) The activity cycle of the CME energy is inferred to be almost in phase with the activity cycle of the sunspot area; the activity cycle of the CME energy at low latitudes slightly leads the activity cycle of the sunspot area; the CME energy at high latitudes is shown to significantly lag behind the sunspot area. iii) The CME energy is shown to significantly lag behind the flare index; the CME energy at low latitudes is shown to slightly lag behind the flare index; the CME energy at high latitudes is shown to significantly lag behind the flare index.

Gao, P. X.; Xie, J. L.; Zhong, J.

2013-10-01

107

ON A CORONAL BLOWOUT JET: THE FIRST OBSERVATION OF A SIMULTANEOUSLY PRODUCED BUBBLE-LIKE CME AND A JET-LIKE CME IN A SOLAR EVENT  

SciTech Connect

The coronal blowout jet is a peculiar category among various jet phenomena, in which the sheared base arch, often carrying a small filament, experiences a miniature version of blowout eruption that produces large-scale coronal mass ejection (CME). In this paper, we report such a coronal blowout jet with high-resolution multi-wavelength and multi-angle observations taken from Solar Dynamics Observatory, Solar Terrestrial Relations Observatory, and Big Bear Solar Observatory. For the first time, we find that simultaneous bubble-like and jet-like CMEs were dynamically related to the blowout jet that showed cool and hot components next to each other. Our observational results indicate that (1) the cool component resulted from the eruption of the filament contained within the jet's base arch, and it further caused the bubble-like CME; (2) the jet-like CME was associated with the hot component, which was the outward moving heated plasma generated by the reconnection of the base arch and its ambient open field lines. On the other hand, bifurcation of the jet's cool component was also observed, which resulted from the uncoupling of the erupting filament's two legs that were highly twisted at the very beginning. Based on these results, we propose a model to interpret the coronal blowout jet, in which the external reconnection not only produces the jet-like CME, but also leads to the rising of the filament. Subsequently, internal reconnection starts underneath the rising filament and thereby causes the bubble-like CME.

Shen Yuandeng; Liu Yu [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China); Su Jiangtao; Deng Yuanyong, E-mail: ydshen@ynao.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012 (China)

2012-02-01

108

Preparation of a Matrix Type MultipleUnit Gastro Retentive Floating Drug Delivery System for Captopril Based on Gas Formation Technique: In Vitro Evaluation  

Microsoft Academic Search

A gastro retentive floating drug delivery system with multiple-unit minitab’s based on gas formation technique was developed\\u000a in order to prolong the gastric residence time and to increase the overall bioavailability of the drug. The system consists\\u000a of the drug-containing core units prepared by direct compression process, which are coated with three successive layers of\\u000a an inner seal coat, effervescent

Lingam Meka; Bhaskar Kesavan; Krishna Mohan Chinnala; Venkateswarlu Vobalaboina; Madhusudan Rao Yamsani

2008-01-01

109

Geometric Localization and Polarimetric Localization: Space Weather Tools to Calculate CME Propagation Characteristics  

NASA Astrophysics Data System (ADS)

The geometric localization technique [Pizzo and Biesecker, 2004] utilizes a series of lines of sight from two space-based coronagraphs to determine gross propagation characteristics of coronal mass ejections (CMEs) in three-dimensional space. The polarimetric localization technique [Moran and Davila, 2004] uses the percent polarization observed by a single coronagraph to obtain a three-dimensional reconstruction of a CME. Both techniques can be used in near-real-time within an operational space weather forecast center. When these two independent techniques are used in conjunction with each other to analyze STEREO/Secchi/COR2 beacon data, they can provide significant constraints on the three-dimensional location and velocity, including speed and direction, for any Earth-directed CME. Here, we employ these techniques to the CME of 31 December 2007 and compare results on the speed and direction of propagation for this CME.

Pizzo, V. J.; de Koning, C. A.

2008-12-01

110

The influence of collagen and hyaluronan matrices on the delivery and bioactivity of bone morphogenetic protein-2 and ectopic bone formation.  

PubMed

Bone morphogenetic protein-2 (BMP-2) is known to enhance fracture healing when delivered via a bovine collagen sponge. However, collagen rapidly releases BMP-2 with a high burst phase that is followed by a low sustained phase. As a result, supra-physiological doses of BMP-2 are often required to successfully treat bone defects. High BMP-2 dosing can introduce serious side effects that include edema, bone overgrowth, cyst-like bone formation and significant inflammation. As the release behavior of BMP-2 carriers significantly affects the efficacy of fracture healing, we sought to compare the influence of two BMP-2 delivery matrices with contrasting release profiles on BMP-2 bioactivity and ectopic bone formation. We compared a thiol-modified hyaluronan (Glycosil™) hydrogel that exhibits a low burst followed by a sustained release of BMP-2 to a collagen sponge for the delivery of three different doses of BMP-2, the bioactivities of released BMP-2 and ectopic bone formation. Analysis of bone formation by micro-computed tomography revealed that low burst followed by sustained release of BMP-2 from a hyaluronan hydrogel induced up to 456% more bone compared to a BMP-2 dose-matched collagen sponge that has a high burst and sustained release. This study demonstrates that BMP-2 released with a low burst followed by a sustained release of BMP-2 is more desirable for bone formation. This highlights the therapeutic potential of hydrogels, particularly hyaluronan-based, for the delivery of BMP-2 for the treatment of bone defects and may help abrogate the adverse clinical effects associated with high dose growth factor use. PMID:23871940

Bhakta, Gajadhar; Lim, Zophia X H; Rai, Bina; Lin, Tingxuan; Hui, James H; Prestwich, Glenn D; van Wijnen, Andre J; Nurcombe, Victor; Cool, Simon M

2013-07-19

111

Induction of thrombolysis and prevention of thrombus formation by local drug delivery with a double-occlusion balloon catheter  

Microsoft Academic Search

Summary The efficacy of the local delivery of an antithrombotic drug in preventing thrombosis and enabling thrombolysis was investigated in 29 dogs. An antithrombotic drug (heparin, 25U\\/kg), or an antithrombin (argatroban, 0.05 mg\\/kg) was infused into injured canine iliac arteries, using a double-occlusion balloon catheter, and the preventive effect of the drug was evaluated. Local delivery of low-dose tissuetype plasminogen

Takanobu Tomaru; Yoshiharu Fujimori; Fumitaka Nakamura; Naoto Aoki; Yoshimitsu Sakamoto; Kohichi Kawai; Masao Omata; Yasumi Uchida

1996-01-01

112

CmeABC Functions as a Multidrug Efflux System in Campylobacter jejuni  

Microsoft Academic Search

Campylobacter jejuni, a gram-negative organism causing gastroenteritis in humans, is increasingly resistant to antibiotics. However, little is known about the drug efflux mechanisms in this pathogen. Here we charac- terized an efflux pump encoded by a three-gene operon (designated cmeABC) that contributes to multidrug resistance in C. jejuni 81-176. CmeABC shares significant sequence and structural homology with known tripartite multidrug

Jun Lin; Linda Overbye Michel; Qijing Zhang

2002-01-01

113

CME, Physicians, and Pavlov: Can We Change What Happens When Industry Rings the Bell?  

PubMed Central

Purpose To show how physicians’ conditioned response to “keeping up” has helped industry’s opportunistic funding of continuing medical education (CME) and to propose ways to counter the conditioned response to the benefit of patients and the public. Methods Review of the literature and commentary on it. Results The pharmaceutical and device industries (hereafter referred to as industry) have a long history of bribing physicians to prescribe and use their products. Increasing pressure from Congress and the public has been brought to bear on industry gifting. This pressure, coinciding with increasing financial problems for the providers of CME, provided industry with reason and opportunity to expand its role in the financing of CME. Industry’s incentive to make its CME funding appear to be an arm’s-length transaction has spawned medical education service supplier (MESS) companies. Industry makes “unrestricted grants” to the MESS, and the MESS puts on the CME program. Helped by these CME programs, industry is able to subtly “buy” physicians one at a time, so that under the cover of “education” they and their academic institutions and medical organizations lose sight of being CME pawns in industry’s sole objective: profit. Conclusions Despite a vast literature showing how physician integrity is easy prey to industry, the medical profession continues to allow industry to have a detrimental influence on the practice of medicine and on physician respectability. It will take resolute action to change the medical profession’s conditioned response to industry’s CME bell and its negative effect on patients and the public.

Lichter, Paul R.

2008-01-01

114

On radar cross-section of the Sun during earthward-directed CME  

NASA Astrophysics Data System (ADS)

In order to design radar experiments for the study of the Sun, it is necessary to make some preliminary estimates. We report results of crude calculations of the solar radar cross section during the appearance of a geoeffective CME. For the calculations, we consider the CME to be a spherical expanding plasma shell with a constant mass moving towards the Earth. Two approximations --- ``mirror reflection'' and ``volume scattering'' --- were used. The dependence of the radar cross-section on amount of mass ejected, expansion speed, velocity of the motion away from the Sun, as well as sounding frequency were obtained. In the ``mirror reflection'' model during geoeffective CME the cross-section should first drops at the moment when the CME leading edge achieves the critical level in the solar corona, at which plasma frequency is equal to the sounding frequency. Then the cross-section slowly increases until the decreasing plasma frequency at the leading edge of the expanding CME becomes less then the sounding frequency. After this, the cross-section attains the value for the quiet Sun. For the ``volume scattering'' model a decrease of the gross section after the leading edge achievement of the critical level is much slower. The effect described could be observed by a solar radar operating in approximate frequency range 10--50 MHz. Criteria of the CME geoefficiency determination with the use of solar radaring are discussed on the base of the results obtained.

Belov, Yu. I.; Grach, S. M.; Rodriguez, P.; Thide, B.; Tokarev, Yu. V.

2003-04-01

115

In situ formation of nanocrystals from a self-microemulsifying drug delivery system to enhance oral bioavailability of fenofibrate  

PubMed Central

Objectives In situ formation of nanocrystals and dissolution profiles of fenofibrate (FFB) from a self-microemulsifying drug delivery system (SMEDDS) were characterized. Methods SMEDDS formulated with Myritol® and surfactant mixture (Smix) of D-?-Tocopheryl polyethylene glycol 1000 succinate (TPGS) and either Tween® 20 (A, C, E, G, M, S, N, T, O) or Tween® 80 (B, D, F, H, P, U, Q, V, R) at various oil/Smix ratios (Group I: A and B of 0.42, C and D of 0.25, E and F of 0.11; Group II: G and H of 1.38, M and P of 1.11, S and U of 0.9, N and Q of 0.73, T and V of 0.58, and O and R of 0.46) and water contents (1: 9.5%, 2: 5.0%, 3: 0.0%, G–V: 4.5%). Their dissolutions were conducted at different rotation speeds. Two optimal SMEDDSs containing Tween 80(B2) or a higher oil/Smix ratio(Q) and B2(solution) were selected for pharmacokinetic study. Results FFB particles formed within the nanosize range from Group I gradually increased with time but decreased with increasing stirring rates. However, the mean size of FFB formed by B series was as low as 200 nm, which was smaller than that of A series at three stirring rates. The release rate from both groups obviously increased with increasing stirring rate. However, incomplete release was observed for S and N in Tween 20 series, whereas a faster release rate and complete release were observed for Tween 80 series with an insignificant difference among them. Results of pharmacokinetic study demonstrated that the highest-ranked area under the curve and Cmax values were for Q(SMEDDS) and B2(solution), respectively. The relative bioavailability of Q(SMEDDS) with respect to Tricor® was enhanced by about 1.14–1.22-fold. Conclusion SMEDDS, consisting of Myritol 318 and TPGS combined with Tween 80 at 4:1, was able to enhance the oral bioavailability of FFB.

Lin, You-Meei; Wu, Jui-Yu; Chen, Ying-Chen; Su, Yu-Der; Ke, Wen-Tin; Ho, Hsiu-O; Sheu, Ming-Thau

2011-01-01

116

CME and Reconnection Contributions to the Interplanetary Magnetic Field  

NASA Astrophysics Data System (ADS)

Examination of L1 magnetic field data from the recent solar minimum reveals evidence for ongoing magnetic reconnection below the Alfven critical point and throughout the recent protracted solar minimum. This ongoing reconnection permits both the ejection of open field lines from the heliosphere and the creation of new magnetic loops that are capable of subduction below the photosphere. At the same time, a theory can be developed based on related published ideas wherein CMEs contribute magnetic field to interplanetary space that, in time, become part of the observed open field line population. What seems most interesting is that (1) throughout the recent protracted solar minimum the IMF flux drops steadily and the apparent reconnection continues at a very steady rate, and (2) the field model can account for this observation by using reasonable parameters for ICME flux content and reconnection rates. We will also show our efforts to account for the interplanetary magnetic field during the rising phase of the solar cycle as CME flux injection is balanced against reduction by field line reconnection.

Connick, D.; Schwadron, N. A.; Smith, C. W.

2011-12-01

117

Solar Flare and CME Observations with STEREO/EUVI  

NASA Astrophysics Data System (ADS)

STEREO/EUVI observed 185 flare events (detected above the GOES class C1 level or at > 25 keV with RHESSI) during the first two years of the mission (December 2006 - November 2008), while coronal mass ejections (CMEs) were reported in about a third of these events. We compile a comprehensive catalog of these EUVI-observed events, containing the peak fluxes in soft X rays, hard X rays, and EUV, as well as a classification and statistics of prominent EUV features: 79% show impulsive EUV emission (coincident with hard X rays), 73% show delayed EUV emission from postflare loops and arcades, 24% represent occulted flares, 17% exhibit EUV dimming, 5% show loop oscillations or propagating waves, and at least 3% show erupting filaments. We analyze an example of each EUV feature by stereoscopic modeling of its 3D geometry. We find that EUV emission can be dominated by impulsive emission from a heated, highly sheared, noneruptive filament, in addition to the more common impulsive EUV emission from flare ribbons or the delayed postflare EUV emission that results from cooling of the soft-X-ray-emitting flare loops. Occulted flares allow us to determine CME-related coronal dimming uncontaminated from flare-related EUV emission. From modeling the time evolution of EUV dimming we can accurately quantify the initial expansion of CMEs and determine their masses. Further, we find evidence that coronal loop oscillations are excited by the rapid initial expansion of CMEs. These examples demonstrate that stereoscopic EUV data provide powerful new methods to model the 3D aspects in the hydrodynamics of flares and kinematics of CMEs.

Aschwanden, M. J.; Wuelser, J. P.; Nitta, N. V.; Lemen, J. R.

2009-05-01

118

The SCEC Community Modeling Environment (SCEC/CME) - An Overview of its Architecture and Current Capabilities  

NASA Astrophysics Data System (ADS)

The Southern California Earthquake Center (SCEC), in collaboration with the San Diego Supercomputer Center, the USC Information Sciences Institute, the Incorporated Research Institutions for Seismology, and the U.S. Geological Survey, is developing the Southern California Earthquake Center Community Modeling Environment (CME) under a five-year grant from the National Science Foundation's Information Technology Research (ITR) Program jointly funded by the Geosciences and Computer and Information Science & Engineering Directorates. The CME system is an integrated geophysical simulation modeling framework that automates the process of selecting, configuring, and executing models of earthquake systems. During the Project's first three years, we have performed fundamental geophysical and information technology research and have also developed substantial system capabilities, software tools, and data collections that can help scientist perform systems-level earthquake science. The CME system provides collaborative tools to facilitate distributed research and development. These collaborative tools are primarily communication tools, providing researchers with access to information in ways that are convenient and useful. The CME system provides collaborators with access to significant computing and storage resources. The computing resources of the Project include in-house servers, Project allocations on USC High Performance Computing Linux Cluster, as well as allocations on NPACI Supercomputers and the TeraGrid. The CME system provides access to SCEC community geophysical models such as the Community Velocity Model, Community Fault Model, Community Crustal Motion Model, and the Community Block Model. The organizations that develop these models often provide access to them so it is not necessary to use the CME system to access these models. However, in some cases, the CME system supplements the SCEC community models with utility codes that make it easier to use or access these models. In some cases, the CME system also provides alternatives to the SCEC community models. The CME system hosts a collection of community geophysical software codes. These codes include seismic hazard analysis (SHA) programs developed by the SCEC/USGS OpenSHA group. Also, the CME system hosts anelastic wave propagation codes including Kim Olsen's Finite Difference code and Carnegie Mellon's Hercules Finite Element tool chain. The CME system can execute a workflow, that is, a series of geophysical computations using the output of one processing step as the input to a subsequent step. Our workflow capability utilizes grid-based computing software that can submit calculations to a pool of computing resources as well as data management tools that help us maintain an association between data files and metadata descriptions of those files. The CME system maintains, and provides access to, a collection of valuable geophysical data sets. The current CME Digital Library holdings include a collection of 60 ground motion simulation results calculated by a SCEC/PEER working group and a collection of Greens Functions calculated for 33 TriNet broadband receiver sites in the Los Angeles area.

Maechling, P. J.; Jordan, T. H.; Minster, B.; Moore, R.; Kesselman, C.; SCEC ITR Collaboration

2004-12-01

119

On the relationship between coronal waves associated with a CME on 5 March 2000  

NASA Astrophysics Data System (ADS)

Aims:To study the relationship between coronal mass ejection (CME) associated waves. Methods: Analysis of CME eruption observations on 5 Mar. 2000 recorded by the Large Angle Spectrometric Coronagraph (LASCO), the Ultraviolet Coronagraph Spectrometer (UVCS), and the Extreme-ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory (SOHO). Results: Images recorded by the LASCO/C2 show a clear deflection and kink in a streamer located eastward of the CME. The kink in the streamer propagated outwards along with the associated CME. No CME material was seen between the bright front of the CME and the streamer. UVCS spectra show large spectral line broadening, Doppler shifts and intensity changes in the O VI (?1032 & 1037) lines. Moreover, intensity enhancements in lines such as Si XII ? 520 and Mg X ? 625 forming at very high temperatures (>2 MK; not often observed in the corona) were also observed. EIT images show the propagation of a wave from the CME source region. The speed of the wave was about 55 km s-1 and it propagated predominantly in the North-East direction from the source region. Furthermore, it does not propagate through active regions and coronal holes. The deflection in the streamer recorded in the LASCO/C2 was in the same direction as that of the EIT wave. Conclusions: Spatial and temporal correlations show that the deflection and the propagation of the kink in the streamer (based on the LASCO data), and plasma heating and spectral line broadening (based on the UVCS data), are basically due to a CME-driven shock wave. The spatial and temporal correlations between the EIT wave and the shock wave provide strong evidence in favor of the interpretation that the EIT waves are indeed the counterpart of CME-driven shock waves in the lower corona. Although, we cannot rule out the possibility that the EIT waves are just a manifestation of the stretching of the field lines due to the outward propagation of the CMEs. The movie is only available in electronic form at http://www.aanda.org

Tripathi, D.; Raouafi, N.-E.

2007-10-01

120

Assessing the Accuracy of the Fixed-Phi Method for Different CME Initial Speeds and Directions  

NASA Astrophysics Data System (ADS)

In order to study CME kinematics in the heliosphere from white-light observations, it is essential to derive precisely the CME positions from the measured elongation angles. In this talk, we discuss one of the simplest and most commonly used approximations used to calculate CME positions from SECCHI measurements: the Fixed-Phi approximation. Our approach is to analyse synthetic line-of-sight images of CMEs produced from a global three-dimensional MHD simulation and to compare the position derived from elongation angles to the position in the 3-D simulation. By testing this approximation for different CME initial speeds and directions of propagation, we are able to quantify the error associated with the method. In particular, this approach is the only way to study the accuracy of this technique for fast CMEs, since there has been almost no fast events since the launch of STEREO. Also, because the elongation angle is not proportional to the radial distance, time-elongation plots of CMEs usually show an apparent deceleration or acceleration of the tracks at large elongation angles, which can be related to the direction of propagation of the CME with respect to the Sun-spacecraft line, assuming a constant propagation speed. We give preliminary results of the errors introduced by this method for fast CMEs propagating with different angles with respect to the STEREO-Sun line.

Lugaz, Noe; Roussev, Ilia I.

2010-05-01

121

A Descriptive-Predictive Model of CME Propagation based on Multi-Instrument Data  

NASA Astrophysics Data System (ADS)

The space weather field has thriven in the past decades, mainly given the proliferation of space missions devoted to study the Sun and its relations to Earth. In addition, the high dependence on technology developed by society demands that a solar event, its time of arrival at Earth, and its degree of geoeffectiveness can be promptly forecasted. The accurate prediction of a CME-driven shock arrival time at Earth is therefore challenging and crucial, so as to take emergency measures when required. In this direction, we have studied 90 Earth-directed events in different stages of their propagation from Sun to Earth. A descriptive model was derived from CME height-time information from SOHO/LASCO coronagraph data, interplanetary shock approximate locations derived from Type II radio emissions detected by Wind/WAVES, and shock time of arrival at L1 as seen in-situ by the ACE and/or Wind spacecraft. The descriptive model provided a general overview of CME-driven shocks kinematics, allowing the determination of typical propagation profiles and constrains on the main parameters. On the basis of these, a predictive model was formulated, which relies on CME and low-frequency type II radio emissions. We discuss results on CME-radio emission associations, characteristics of the propagation in the interplanetary medium, and the success of the predictive model to forecast the arrival times of shocks at Earth.

Cremades, H.; Iglesias, F. A.; St Cyr, O. C.; Kaiser, M. L.; Xie, H.; Quirk, C. A.

2011-12-01

122

A pH-responsive chitosan-b-poly(p-dioxanone) nanocarrier: formation and efficient antitumor drug delivery  

NASA Astrophysics Data System (ADS)

Increasing attention has recently been paid to the fabrication of drug delivery systems with excellent cell internalization and intracellular drug release properties. In this study, an amphiphilic block copolymer of chitosan was synthesized for the first time, which can self-assemble into micelles in a neutral aqueous solution but partially disassemble in an acidic endosomal/lysosomal environment. The antitumor drug, camptothecin (CPT), was encapsulated in the cores of the micelles for tumor cell therapy. In vitro drug release studies demonstrated that the micelles presented a much faster release of CPT at pH 5.0 than at pH 7.4. Blank micelles were found to be nontoxic in preliminary in vitro cytotoxicity assays. Cell experiments showed that the CPT-loaded micelles could be effectively internalized by Hela cells and accomplished a potent antitumor cell efficacy, indicating that the chitosan-based micelles might be an attractive new platform for efficient intracellular drug delivery.

Tang, Dao-Lu; Song, Fei; Chen, Cheng; Wang, Xiu-Li; Wang, Yu-Zhong

2013-04-01

123

Herpes simplex virus amplicon delivery of a hypoxia-inducible angiogenic inhibitor blocks capillary formation in hepatocellular carcinoma  

Microsoft Academic Search

Tumor hypoxia induces vascular endothelial growth factor (VEGF) expression, which stimulates tumor angiogenesis. The VEGF\\u000a pathway is inhibited by soluble VEGF receptors (soluble fetal liver kinase-1 [sFlk-1]) that bind VEGF and block its interaction\\u000a with endothelial cells. Herpes simplex virus (HSV)-derived amplicons are replication-incompetent viruses used for gene delivery.\\u000a We attempt to attenuate angiogenesis and inhibit hepatoma growth through amplicon-mediated

Richard H. Pin; Maura Reinblatt; William J. Bowers; Howard J. Federoff; Yuman Fong

2004-01-01

124

Multi-wavelength study of a CME-driven shock at 4.1 solar radii  

NASA Astrophysics Data System (ADS)

We report on the analysis of a peculiar fast CME-driven shock associated to the eruption of March 22, 2002. The event was observed by the SOHO/UVCS instrument at 4.1 solar radii, with the spectrometer slit placed in correspondence of the flank of the expanding CME. Signatures of a strong MHD shock are observed in radio data (where a type-II radio burst was observed), white light SOHO/LASCO images (where a spherical density gradient located above the expanding CME front was observed) and in SOHO/UVCS spectra (where strong line broadenings are observed). UVCS, LASCO and radio data have been coupled to estimate not only the shock compression ratio and the pre-and post-shock plasma temperatures, but also, by applying the Rankine-Hugoniot equations for the general case of an oblique shock, the strength of the involved coronal magnetic fields.

Bemporad, Alessandro; Mancuso, Salvatore

125

SEP Acceleration at CME Driven Shocks: Numerical Simulation with Evolving Shock Geometry and Downstream Structure  

NASA Astrophysics Data System (ADS)

Gradual solar energetic particle (SEP) events are believed to be accelerated at CME driven shocks. Shocks driven by a realistic CMEs are neither simply quasi-perpendicular nor quasi-parallel: the geometry and the shock strength may constantly change as the CME evolves. The shock is likely to be quasi-perpendicular when it forms and becomes more parallel at later stages (Tylka and Lee, 2006). The downstream sheath region immediately behind the shock has a structure of its own, which may play a significant role in the SEP acceleration process. We present numerical simulations adopting a Lagrangian scheme which is designed to handle the evolution of the shock. The scheme follows the moving magnetic field lines, which are wrapped around the expanding CME, and are pushed by the ejecta. We present numerical simulation results and discuss their implications. Tyka, A,J, and M.A. Lee, Astrophys. ~J., 646, 1319 (2006)

Kota, J.; Giacalone, J.; Jokipii, J. R.

2006-12-01

126

Coronal Mass Ejection of 26 February 2000: Complete analysis of the three-part CME structure  

NASA Astrophysics Data System (ADS)

We analyze the kinematics and morphology of the limb coronal mass ejection (CME) of 26 February 2000, utilizing observations from Mauna Loa Solar Observatory (MLSO), the Solar and Heliospheric Observatory (SOHO) and the Geostationary Operational Environmental Satellite (GOES). Also, we analyze the relation between dynamics of the CME and the energy release in the associated flare. An intricate structure (prominence, prominence-like absorbing feature, cavity and bright overlying arcade) is clearly recognizable in the low corona during the pre-eruption phase of slow rise. This provided measurements of kinematics of verious features from the very beginning of the eruption up to the post-acceleration phase which was followed up to 32 solar radii. Such events are observed only occasionaly, and are of great importance for the comprehension of the nature of forces driving CMEs. The acceleration maximum was attained at the radial distance of 2.4 solar radii from the solar center and ceased beyond 12 solar radii. The time profiles of the acceleration of various features of CME are showing "self-similar" expansion and implying a common driver. The acceleration phase was synchronized to a certain degree with the impulsive phase of the associated two-ribbon flare. Observations provide clear evidence that CME eruption caused a global restructuring of the magnetic field in the outer and inner corona. Furthermore, kinematics and morphological properties of this CME show possibility that in some events the prominence can evolve into a structure which looks like three-part structure CME, i.e. where the frontal rim is just a part of helically twisted prominence.

Mari?i?, D.; Vršnak, B.; Roša, D.; Hržina, D.

2012-11-01

127

Enhancing quality improvements in cancer care through CME activities at a nationally recognized cancer center.  

PubMed

Changing healthcare policy will undoubtedly affect the healthcare environment in which providers function. The current Fee for Service reimbursement model will be replaced by Value-Based Purchasing, where higher quality and more efficient care will be emphasized. Because of this, large healthcare organizations and individual providers must adapt to incorporate performance outcomes into patient care. Here, we present a Continuing Medical Education (CME)-based initiative at the City of Hope National Cancer Center that we believe can serve as a model for using CME as a value added component to achieving such a goal. PMID:23608956

Uemura, Marc; Morgan, Robert; Mendelsohn, Mary; Kagan, Jean; Saavedra, Crystal; Leong, Lucille

2013-06-01

128

Role of Ambient Solar Wind Conditions in CME evolution (P21)  

NASA Astrophysics Data System (ADS)

ipsraj@yahoo.com Solar events are mainly responsible for producing storms at the Earth. Coronal Mass Ejection (CME) is a major cause for this. In this paper, Coronal Mass Ejections occurred during 1998-2004 are studied. Ambient solar wind does play some role in determining the effect of a CME. The effects produced at the Earth during the period 1999 2004 are considered and an attempt has been made to understand the role of ambient solar wind. This is to draw some conclusion about how some of the events become geo- effective.

Jadav, R.; Jadeja, A. K.; Iyer, K. N.

2006-11-01

129

Analysis and study of the in situ observation of the June 1st 2008 CME by STEREO  

Microsoft Academic Search

In this work we present a combined study of the counterpart of the coronal mass ejection (CME) of June 1st of 2008 in the interplanetary medium. This event has been largely studied because of its peculiar initiation and its possible forecasting consequences for space weather. We show an in situ analysis (on days June 6th–7th of 2008) of the CME

T. Nieves-Chinchilla; R. Gómez-Herrero; A. F. Viñas; O. Malandraki; N. Dresing; M. A. Hidalgo; A. Opitz; J.-A. Sauvaud; B. Lavraud; J. M. Davila

2011-01-01

130

Dual Delivery of rhPDGF-BB and Bone Marrow Mesenchymal Stromal Cells Expressing the BMP2 Gene Enhance Bone Formation in a Critical-Sized Defect Model.  

PubMed

Bone tissue healing is a dynamic, orchestrated process that relies on multiple growth factors and cell types. Platelet-derived growth factor-BB (PDGF-BB) is released from platelets at wound sites and induces cellular migration and proliferation necessary for bone regeneration in the early healing process. Bone morphogenetic protein-2 (BMP-2), the most potent osteogenic differentiation inducer, directs new bone formation at the sites of bone defects. This study evaluated a combinatorial treatment protocol of PDGF-BB and BMP-2 on bone healing in a critical-sized defect model. To mimic the bone tissue healing process, a dual delivery approach was designed to deliver the rhPDGF-BB protein transiently during the early healing phase, whereas BMP-2 was supplied by rat bone marrow stromal cells (BMSCs) transfected with an adenoviral vector containing the BMP2 gene (AdBMP2) for prolonged release throughout the healing process. In in vitro experiments, the dual delivery of rhPDGF-BB and BMP2 significantly enhanced cell proliferation. However, the osteogenic differentiation of BMSCs was significantly suppressed even though the amount of BMP-2 secreted by the AdBMP2-transfected BMSCs was not significantly affected by the rhPDGF-BB treatment. In addition, dual delivery inhibited the mRNA expression of BMP receptor type II and Noggin in BMSCs. In in vivo experiments, critical-sized calvarial defects in rats showed enhanced bone regeneration by dual delivery of autologous AdBMP2-transfected BMSCs and rhPDGF-BB in both the amount of new bone formed and the bone mineral density. These enhancements in bone regeneration were greater than those observed in the group treated with AdBMP2-transfected BMSCs alone. In conclusion, the dual delivery of rhPDGF-BB and AdBMP2-transfected BMSCs improved the quality of the regenerated bone, possibly due to the modulation of PDGF-BB on BMP-2-induced osteogenesis. PMID:23901900

Park, Shin-Young; Kim, Kyoung-Hwa; Shin, Seung-Yun; Koo, Ki-Tae; Lee, Yong-Moo; Seol, Yang-Jo

2013-07-31

131

Effects of efflux-pump inducers and genetic variation of the multidrug transporter cmeB in biocide resistance of Campylobacter jejuni and Campylobacter coli.  

PubMed

Multidrug efflux pumps, such as CmeABC and CmeDEF, are involved in the resistance of Campylobacter to a broad spectrum of antimicrobials. The aim of this study was to analyse the effects of two putative efflux-pump inducers, bile salts and sodium deoxycholate, on the resistance of Campylobacter to biocides (triclosan, benzalkonium chloride, chlorhexidine diacetate, cetylpyridinium chloride and trisodium phosphate), SDS and erythromycin. The involvement of the CmeABC and CmeDEF efflux pumps in this resistance was studied on the basis of the effects of bile salts and sodium deoxycholate in Campylobacter cmeB, cmeF and cmeR mutants. The genetic variation in the cmeB gene was also examined, to see whether this polymorphism is related to the function of the efflux pump. In 15 Campylobacter jejuni and 23 Campylobacter coli strains, bile salts and sodium deoxycholate increased the MICs of benzalkonium chloride, chlorhexidine diacetate, cetylpyridinium chloride and SDS, and decreased the MICs of triclosan, trisodium phosphate and erythromycin. Bile salts and sodium deoxycholate further decreased or increased the MICs of biocides and erythromycin in the cmeF and cmeR mutants. For cmeB polymorphisms, 17 different cmeB-specific PCR-RFLP patterns were identified: six within C. jejuni only, nine within C. coli only and two in both species. In conclusion, bile salts and sodium deoxycholate can increase or decrease bacterial resistance to structurally unrelated antimicrobials. The MIC increases in the cmeF and cmeR mutants indicated that at least one non-CmeABC efflux system is involved in resistance to biocides. These results indicate that the cmeB gene polymorphism identified is not associated with biocide and erythromycin resistance in Campylobacter. PMID:23161768

Mavri, Ana; Smole Možina, Sonja

2012-11-15

132

Preparation and in vitro characterization of a eutectic based semisolid self-nanoemulsified drug delivery system (SNEDDS) of ubiquinone: mechanism and progress of emulsion formation.  

PubMed

The objectives of the present work were, first, to develop a self-nanoemulsified drug delivery system (SNEDDS) based on the eutectic properties of ubiquinone (CoQ10); and second, to study the progress of emulsion formation and drug release mechanisms by turbidimetry and droplet size analysis. Binary phase diagrams of CoQ10 with menthol and essential oils were constructed and used to develop the self-nanoemulsified formulation. Pseudo ternary phase diagram was constructed to identify the efficient self-emulsification region. Release mechanisms of the resultant formulas were quantified using turbidimetry in combination with dissolution studies. Turbidity time profiles revealed three distinctive regions: lag phase, plateau, and the pseudolinear phase. Lag phase was attributed to the liquid crystalline properties of the formula. Plateau turbidity was correlated with droplet size. Laser diffraction analysis revealed an average droplet diameter of 100 nm. Emulsification rate was obtained from the corrected slope of the pseudolinear phase of the profile. Stability of the formula was further evaluated using Fourier transform-infrared (FT-IR) attached to an attenuated total reflectance (ATR) accessory. The present study revealed a eutectic based semisolid self-emulsified delivery system that can overcome the drawbacks of the traditional emulsified systems such as low solubility and irreversible precipitation of the active drug in the vehicle with time. PMID:11879759

Nazzal, S; Smalyukh, I I; Lavrentovich, O D; Khan, Mansoor A

2002-03-20

133

Preparation of a Matrix Type Multiple-Unit Gastro Retentive Floating Drug Delivery System for Captopril Based on Gas Formation Technique: In Vitro Evaluation  

PubMed Central

A gastro retentive floating drug delivery system with multiple-unit minitab’s based on gas formation technique was developed in order to prolong the gastric residence time and to increase the overall bioavailability of the drug. The system consists of the drug-containing core units prepared by direct compression process, which are coated with three successive layers of an inner seal coat, effervescent layer (sodium bicarbonate) and an outer gas-entrapped polymeric membrane of an polymethacrylates (Eudragit RL30D, RS30D, and combinations of them). Only the system using Eudragit RL30D and combination of them as a gas-entrapped polymeric membrane could float. The time to float decreased as amount of the effervescent agent increased and coating level of gas-entrapped polymeric membrane decreased. The optimum system floated completely within 3 min and maintained the buoyancy over a period of 12 h. The drug release was controlled and linear with the square root of time. Increasing coating level of gas-entrapped polymeric membrane decreased the drug release. Both the rapid floating and the controlled release properties were achieved in the multiple-unit floating drug delivery system developed in this present study. The analysis of the parameter dissolution data after storage at 40 °C and 75% RH for 3 months showed, no significant change indicating the two dissolution profiles were considered to be similar (f2 value is more than 50).

Kesavan, Bhaskar; Chinnala, Krishna Mohan; Vobalaboina, Venkateswarlu; Yamsani, Madhusudan Rao

2008-01-01

134

INVESTIGATION OF THE FORMATION AND SEPARATION OF AN EXTREME-ULTRAVIOLET WAVE FROM THE EXPANSION OF A CORONAL MASS EJECTION  

SciTech Connect

We address the nature of EUV waves through direct observations of the formation of a diffuse wave driven by the expansion of a coronal mass ejection (CME) and its subsequent separation from the CME front. The wave and the CME on 2011 June 7 were well observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. Following the solar eruption onset, marked by the beginning of the rapid increasing of the CME velocity and the X-ray flux of accompanying flare, the CME exhibits a strong lateral expansion. During this impulsive expansion phase, the expansion speed of the CME bubble increases from 100 km s{sup -1} to 450 km s{sup -1} in only six minutes. An important finding is that a diffuse wave front starts to separate from the front of the expanding bubble shortly after the lateral expansion slows down. Also a type II burst is formed near the time of the separation. After the separation, two distinct fronts propagate with different kinematic properties. The diffuse front travels across the entire solar disk, while the sharp front rises up, forming the CME ejecta with the diffuse front ahead of it. These observations suggest that the previously termed EUV wave is a composite phenomenon and driven by the CME expansion. While the CME expansion is accelerating, the wave front is cospatial with the CME front, thus the two fronts are indiscernible. Following the end of the acceleration phase, the wave moves away from the CME front with a gradually increasing distance between them.

Cheng, X.; Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Zhang, J. [School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, VA 22030 (United States); Olmedo, O. [NRC, Naval Research Laboratory, Washington, DC 20375 (United States); Vourlidas, A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Liu, Y., E-mail: dmd@nju.edu.cn, E-mail: jzhang7@gmu.edu [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States)

2012-01-20

135

Long-term evaluation of recombinant human bone morphogenetic protein-2 induced bone formation with a biologic and synthetic delivery system.  

PubMed

The efficacy of microspheres made of polylactic acid polyglycolic acid copolymer mixed with blood clot as a delivery system for recombinant human bone morphogenetic protein-2 (rhBMP-2) was evaluated and the long term behaviour of rhBMP-2 in rats was studied. Twenty micro grams of rhBMP-2 in 200 microliter carrier (blood coagulum and polylactic acid polyglycolic acid porous microspheres) were implanted subcutaneously over both sides of the chest muscles in 40 5-week-old male Long Evans rats. The control group were implanted with carrier alone. Specimens were retrieved after 3 days and weekly for 9 weeks. Outcome was measured by signs of bone formation on low power radiographs, and signs of bony growth on histological examination. There were no signs of foreign body or inflammatory reactions to the carrier in either group. In the experimental group signs of bone formation had started to appear by the end of the first week, and there was a gradual increase in both radio-opacity and size during the observation period. Histologically the bony growth was beginning to mature by 4 weeks and was fully mature by 7-9 weeks. In contrast there was no sign of cartilage or bone formation in the control group and the carrier had resorbed by 4-6 weeks. It is concluded that rhBMP-2 implanted in a carrier consisting of blood clot and porous microspheres made of polylactic acid polyglycolic acid induces rapid proliferation of mesenchymal cells that lead to formation of cartilage and bone by 7 days which had matured by 9 weeks. rhBMP-2 in this carrier may be useful clinically because of its capacity to induce early formation of bone. PMID:8909733

Alpaslan, C; Irie, K; Takahashi, K; Ohashi, N; Sakai, H; Nakajima, T; Ozawa, H

1996-10-01

136

Organizational Change in Management of Hepatitis C: Evaluation of a CME Program  

ERIC Educational Resources Information Center

|Introduction: Effective treatment regimens exist for the hepatitis C virus (HCV); however, clinicians are often resistant to evaluation or treatment of patients with alcohol or substance abuse problems. We describe a continuing medical education (CME) program for clinicians in a nationwide health care system, with emphasis on current treatment…

Garrard, Judith; Choudary, Veena; Groom, Holly; Dieperink, Eric; Willenbring, Mark L.; Durfee, Janet M.; Ho, Samuel B.

2006-01-01

137

Post-CME Reconnection and the Generation of Descending Solar Coronal Voids  

NASA Astrophysics Data System (ADS)

Observations of solar coronal flares occurring behind coronal mass ejections (CME's) have shown downflowing voids in the corona, which are believed to be the signatures of descending magnetic flux tubes. We are studying the hypothesis that these flux tubes have reconnected in the current sheet which forms behind the CME in the high corona. We will present three dimensional MHD simulations of a localized reconnection event in a Y-type post-CME current sheet. The reconnected field creates a downflow which rapidly decelerates as it hits the Y-line and the magnetic loops below it. We will compare this deceleration with the observed deceleration of coronal voids when they hit coronal arcades. We will also present studies of the 3D tearing mode in this current sheet. This tearing generates numerous localized reconnection patches, and a cascade of reconnected fluxtubes. We will compare this cascade with the the cascades of descending voids and coronal loops which are seen following a CME event, providing further evidence that the observed voids are reconnected flux tubes. This research was supported by grants from NASA and ONR.

Linton, Mark; Longcope, D.; Warren, H.

2007-05-01

138

The Integrated Joslin Performance Improvement/CME Program: A New Paradigm for Better Diabetes Care  

ERIC Educational Resources Information Center

|Ongoing continuing medical education is an essential component of life-long learning and can have a positive influence on patient outcomes. However, some evidence suggests that continuing medical education has not fulfilled its potential as a performance improvement (PI) tool, in part due to a paradigm of CME that has focused on the quantity of…

Brown, Julie A.; Beaser, Richard S.; Neighbours, James; Shuman, Jill

2011-01-01

139

Tracking of Interplanetary CME/Shocks evolution using Type II radio burst observations  

NASA Astrophysics Data System (ADS)

The aim of this work is to apply a new analysis technique, using Type II radio observations in the kilometric (km) domain obtained by the Thermal Noise Receiver (TNR) of the WIND/WAVES experiment, to infer the speed evolution of interplanetary (IP) CME/shocks. These CME/Shocks propagating in the IP medium can generate km Type II radio emissions that occur at the fundamental and/or harmonic of the plasma frequency, so these radio emissions provide a means of remotely tracking CME/shocks. We combine our results with previously reported speeds from coronagraph white light and interplanetary scintillation observations, and in-situ measurements, to study the temporal speed evolution of these events. The shock speed values obtained by our analysis technique are in a reasonable agreement with the speed measurements inferred by other techniques at different heliocentric distance ranges. The combination of all the speed measurements show a gradual deceleration of the CME/shocks as they propagate to 1 AU.

Aguilar-Rodriguez, E.; Gonzalez-Esparza, A.; Ontiveros, V.

2010-12-01

140

Using Standardized Patients in CME Courses on Proper Prescribing of Controlled Substances  

Microsoft Academic Search

Introduction: Controlled prescription drug (CPD) abuse is an increasing threat to patient safety and health care providers (HCP) are not adequately prepared nor do they routinely employ proper screening techniques. Using Standardized Patients (SP) as an instructional strategy we trained physicians on proper prescribing practices and SBIRT (Screening, Brief Intervention and Referral to Treatment)in a continuing medical education (CME) course.Methods:

William H. Swiggart; Marine V. Ghulyan; Charlene M. Dewey

2012-01-01

141

Tests of Dynamical Flux Emergence as a Mechanism for CME Initiation.  

National Technical Information Service (NTIS)

Current coronal mass ejection (CME) models set their lower boundary to be in the lower corona. They do not calculate accurately the transfer of free magnetic energy from the convection zone to the magnetically dominated corona because they model the effec...

J. E. Leake M. G. Linton S. K. Antiochos

2010-01-01

142

Combined Analysis of Ultraviolet and Radio Observations of the 7 May 2004 CME/Shock Event  

NASA Astrophysics Data System (ADS)

We report results from the combined analysis of UV and radio observations of a CME-driven shock observed on 7 May 2004 above the southeast limb of the Sun at 1.86 R ? with the Ultraviolet Coronagraph Spectrometer (UVCS) on board the Solar and Heliospheric Observatory (SOHO). The coronal mass ejection (CME) was first detected in white-light by the SOHO's Large Angle and Spectrometric Coronagraph (LASCO) C2 telescope and shock-associated type II metric emission was recorded simultaneously by ground-based radio spectrographs. The shock speed (˜ 690 km s-1), as deduced from the analysis of the type II emission drift in the radio spectra and the pre-shock local electron density estimated with the diagnostics provided by UVCS observations of the O vi ?? 1031.9, 1037.6 doublet line intensities, is just a factor ˜ 0.1 higher than the CME speed inferred by means of the white-light (and EUV) data in the middle corona. The local magnetosonic speed, computed from a standard magnetic field model, was estimated as high as ˜ 600 km s-1, implying that the CME speed was probably just sufficient to drive a weak fast-mode MHD shock ahead of the front. Simultaneously with the type II radio emission, significant changes in the O vi doublet line intensities and profiles were recorded in the UVCS spectra and found compatible with abrupt post-shock plasma acceleration and modest ion heating. This work provides further evidence for the CME-driven origin of the shocks observed in the middle corona.

Mancuso, Salvatore

2011-11-01

143

SMEI and IPS 3-D CME Reconstructions, and What They Indicate of Heliospheric Solar Wind Acceleration  

NASA Astrophysics Data System (ADS)

The remotely-sensed measurements of coronal mass ejections (CMEs) and their interplanetary counterparts (ICMEs) from Solar Mass Ejection Imager (SMEI) white-light brightness and radio interplanetary scintillation (IPS) data can be used to provide limits on the acceleration and deceleration of transients in the inner heliosphere. As an intermediate measurement between the Sun and 1 AU, the limits provided by remote sensing are convolved with line-of-sight effects and CME/ICME `evolution' as each feature of the transient moves outward from the Sun. Here we review a few of the popular events and studies that have been presented to show how CME propagation proceeds in the inner heliosphere. Often, the apparent acceleration shown can only be provided by employing an assumption of the CME three-dimensional (3-D) shape, which often changes with solar distance and CME visibility along the line of sight. This assumption can often abrogate the original acceleration measurement. In particular we concentrate here on the analysis of two events during periods in 02-04 November 2003, and also in January 2010 showing how each event provides significantly different acceleration profiles depending on which structures are identified in each transient. Finally, we highlight the strange case of polar coronal jets (that are essentially miniature CMEs) frequently observed to move outward in the polar coronal fast wind at speeds of over three times ambient. These small solar wind transients seem to have disappeared by the time they can be observed in Ulysses in-situ data. Thus, a detailed study of these jets may provide an understanding of smaller-scale CME/ICME deceleration processes.

Jackson, B. V.; Clover, J. M.; Hick, P. P.; Buffington, A.; Bisi, M. M.; Tokumaru, M.

2011-12-01

144

Formation and characterization of chitosan-polylacticacid-polyethylene glycol-gelatin nanoparticles: a novel biosystem for controlled drug delivery.  

PubMed

Chitosan (CS)-polylacticacid (PLA)-polyethylene glycol (PEG)-gelatin (G) nanoparticles, a novel drug vehicle for the controlled release of an antitubercluosis drug, rifampicin (RIF) was developed and its chemical and biochemical activities were studied by various standard methods. The designed carriers CS, PEG and G nanoparticles were prepared by emulsion solvent evaporation technique, and then used for entrapping RIF. Linking was confirmed by FTIR spectroscopy. The surface morphology of the nanoparticles was studied using scanning electron microscope and polarizing microscope. The influence of process variables, on particle size, zeta potential and matrix entrapment of RIF was studied. The encapsulation and loading capacity were evaluated, and an in vitro release of RIF was assessed using the dialysis method. The effect of nanoencapsulation of RIF on the antibacterial activity of RIF against Mycobacterium strains was evaluated. The preliminary results clearly suggested that the cross linked CS-PLA-PEG-G matrix may be a potential polymeric carrier for controlled delivery of RIF. PMID:23987433

Rajan, M; Raj, V

2013-05-21

145

CD151 gene delivery increases eNOS activity and induces ECV304 migration, proliferation and tube formation  

Microsoft Academic Search

Aim:To investigate the effects of CD151 on the activity of endothelial NO synthase (eNOS), and ECV304 migration, proliferation and tube formation.Methods:pAAV-CD151 and pAAV-anti-CD151 were constructed and used to transiently transfect ECV304 mediated with Lipofectamine 2000. After transfection, the expression of CD151 was measured by Western blotting. Cell migration assay was performed using Boyden transwell; proliferation assay was evaluated using the

Zhen-zhong Zheng; Zheng-xiang Liu

2007-01-01

146

Competitive displacement of drugs from cyclodextrin inclusion complex by polypseudorotaxane formation with poloxamer: implications in drug solubilization and delivery.  

PubMed

The competitive interactions between the poly-[propylene oxide] (POO)-poly-[ethylene oxide] (PEO) block copolymer poloxamer 407 (Pluronic F127) and two drugs, triamcinolone acetonide and ciclopirox olamine, by the formation of inclusion complexes with two cyclodextrin hydrophilic derivatives, hydroxypropyl-?-cyclodextrin (HP?CD; molar substitution (MS) 0.65) and partially methylated-?-cyclodextrin (M?CD; MS 0.57), were studied by means of one-dimensional (1)H NMR, 2D ROESY experiments, solubility studies and drug release studies. 1D and 2D NMR and solubility studies indicate that both triamcinolone acetonide and ciclopirox olamine form stable inclusion complexes with the cyclodextrin derivatives. In the case of ciclopirox olamine the complex was more stable at pH 1. Effective complexation of poloxamer with the two cyclodextrins (CDs) was also evidenced by NMR analysis, and competitive displacement of the drugs from the CD cavity by the polymer was observed. Drug solubility in CD solutions was not modified by the addition of polymers, indicating that a decrease in solubility due to the competitive displacement is probably compensated by the solubilizing effect of polymer micellization. Finally, polypseudorotaxanes formation has a significant influence on the release of the drugs studied. Changes in the release rate depend on the stability of drug-CD inclusion complex and on cyclodextrin concentration in the bulk solution; so polypseudorotaxane formation can be employed to modulate drug controlled release from thermosensitive hydrogels. PMID:22182528

Nogueiras-Nieto, Luis; Sobarzo-Sánchez, Eduardo; Gómez-Amoza, José Luis; Otero-Espinar, Francisco J

2011-12-13

147

Probing the Role of Magnetic-Field Variations in NOAA AR 8038 in Producing a Solar Flare and CME on 12 May 1997  

NASA Astrophysics Data System (ADS)

We carried out a multi-wavelength study of a Coronal Mass Ejection (CME) and an associated flare, occurring on 12 May 1997. We present a detailed investigation of magnetic-field variations in NOAA Active Region 8038 which was observed on the Sun during 7 - 16 May 1997. This region was quiet and decaying and produced only a very small flare activity during its disk passage. However, on 12 May 1997 it produced a CME and associated medium-size 1B/C1.3 flare. Detailed analyses of H? filtergrams and SOHO/MDI magnetograms revealed continual but discrete surge activity, and emergence and cancellation of flux in this active region. The movie of these magnetograms revealed the two important results that the major opposite polarities of pre-existing region as well as in the emerging-flux region were approaching towards each other and moving magnetic features (MMF) were ejected from the major north polarity at a quasi-periodicity of about ten hours during 10 - 13 May 1997. These activities were probably caused by magnetic reconnection in the lower atmosphere driven by photospheric convergence motions, which were evident in magnetograms. The quantitative measurements of magnetic-field variations such as magnetic flux, gradient, and sunspot rotation revealed that in this active region, free energy was slowly being stored in the corona. Slow low-layer magnetic reconnection may be responsible for the storage of magnetic free energy in the corona and the formation of a sigmoidal core field or a flux rope leading to the eventual eruption. The occurrence of EUV brightenings in the sigmoidal core field prior to the rise of a flux rope suggests that the eruption was triggered by the inner tether-cutting reconnection, but not the external breakout reconnection. An impulsive acceleration, revealed from fast separation of the H ? ribbons of the first 150 seconds, suggests that the CME accelerated in the inner corona, which is also consistent with the temporal profile of the reconnection electric field. Based on observations and analysis we propose a qualitative model, and we conclude that the mass ejections, filament eruption, CME, and subsequent flare were connected with one another and should be regarded within the framework of a solar eruption.

Jain, Rajmal; Awasthi, Arun K.; Chandel, Babita; Bharti, Lokesh; Hanaoka, Y.; Kiplinger, A. L.

2011-07-01

148

The SCEC Community Modeling Environment(SCEC/CME): A Collaboratory for Seismic Hazard Analysis  

NASA Astrophysics Data System (ADS)

The SCEC Community Modeling Environment (SCEC/CME) Project is an NSF-supported Geosciences/IT partnership that is actively developing an advanced information infrastructure for system-level earthquake science in Southern California. This partnership includes SCEC, USC's Information Sciences Institute (ISI), the San Diego Supercomputer Center (SDSC), the Incorporated Institutions for Research in Seismology (IRIS), and the U.S. Geological Survey. The goal of the SCEC/CME is to develop seismological applications and information technology (IT) infrastructure to support the development of Seismic Hazard Analysis (SHA) programs and other geophysical simulations. The SHA application programs developed on the Project include a Probabilistic Seismic Hazard Analysis system called OpenSHA. OpenSHA computational elements that are currently available include a collection of attenuation relationships, and several Earthquake Rupture Forecasts (ERFs). Geophysicists in the collaboration have also developed Anelastic Wave Models (AWMs) using both finite-difference and finite-element approaches. Earthquake simulations using these codes have been run for a variety of earthquake sources. Rupture Dynamic Model (RDM) codes have also been developed that simulate friction-based fault slip. The SCEC/CME collaboration has also developed IT software and hardware infrastructure to support the development, execution, and analysis of these SHA programs. To support computationally expensive simulations, we have constructed a grid-based scientific workflow system. Using the SCEC grid, project collaborators can submit computations from the SCEC/CME servers to High Performance Computers at USC and TeraGrid High Performance Computing Centers. Data generated and archived by the SCEC/CME is stored in a digital library system, the Storage Resource Broker (SRB). This system provides a robust and secure system for maintaining the association between the data seta and their metadata. To provide an easy-to-use system for constructing SHA computations, a browser-based workflow assembly web portal has been developed. Users can compose complex SHA calculations, specifying SCEC/CME data sets as inputs to calculations, and calling SCEC/CME computational programs to process the data and the output. Knowledge-based software tools have been implemented that utilize ontological descriptions of SHA software and data can validate workflows created with this pathway assembly tool. Data visualization software developed by the collaboration supports analysis and validation of data sets. Several programs have been developed to visualize SCEC/CME data including GMT-based map making software for PSHA codes, 4D wavefield propagation visualization software based on OpenGL, and 3D Geowall-based visualization of earthquakes, faults, and seismic wave propagation. The SCEC/CME Project also helps to sponsor the SCEC UseIT Intern program. The UseIT Intern Program provides research opportunities in both Geosciences and Information Technology to undergraduate students in a variety of fields. The UseIT group has developed a 3D data visualization tool, called SCEC-VDO, as a part of this undergraduate research program.

Maechling, P. J.; Jordan, T. H.; Minster, J. B.; Moore, R.; Kesselman, C.

2005-12-01

149

Compressed antisolvent precipitation and photopolymerization for the formation of crosslinked polymer microparticles useful for controlled drug delivery  

NASA Astrophysics Data System (ADS)

This work presents novel antisolvent processing technique entitled Compressed Antisolvent Precipitation and Photopolymerization (CAPP) useful for forming crosslinked polymer microparticles. In this process, an organic solvent dissolves monomer and polymerization photoinitiators to form a homogeneous solution. Photopolymerization and microparticle formation occur when the homogeneous solution is sprayed into a compressed antisolvent while being simultaneously exposed to initiating light. We investigated the method of particle formation in the CAPP process to explain the repeatable bimodal particle size distribution obtained under a variety of operating conditions. Ternary phase diagrams of antisolvent, monomer, and solvent solutions were constructed and specific spray paths from the resulting ternary phase diagrams were investigated and the significance of crossing the binodal, as well as the importance of where the binodal was crossed, was discovered. In addition, manipulation of injection conditions, varying process residence times, and nucleation rate calculations were explored to further investigate the means of particle formation. We demonstrate the feasibility of encapsulating therapeutic agents into highly crosslinked polymer particles using the CAPP process. Ion-paired tacrine, erythromycin, erythromycin estolate, and erythromycin ethyl succinate were CAPP processed with poly(ethylene glycol) diacrylate monomers of several molecular weights so that the resulting particles would entrap different sized drugs in networks with varying mesh sizes. In vitro drug release profiles were obtained for all of the various drug-monomer combinations. Diffusion coefficients were estimated by fitting a short time approximation of Fickian release from a sphere of fixed diameter to the release data and were applied to a model of Fickian release from polydisperse spheres, and the results were compared to the in vitro release data. CAPP particle processing was explored in acetone, ethanol, and methanol with respect to reaction kinetics, particle size and morphology, particle double bond conversion, and in vitro drug release. A multifunctional anhydride monomer was also applied to the CAPP process and ion-paired tacrine was successfully encapsulated in the resulting surface eroding, crosslinked polymer microparticles. Degradation of and release from thin disks of photopolymerized monomer, poly(sebacic anhydride dimethacrylate), gave a kinetic constant for surface erosion, which was applied to predict the release of ion-paired tacrine from the CAPP-processed, degradable particles.

Owens, Jennifer Lani

150

Effect of Autologous Bone Marrow Stromal Cell Seeding and Bone Morphogenetic Protein-2 Delivery on Ectopic Bone Formation in a Microsphere/Poly(Propylene Fumarate) Composite  

PubMed Central

A biodegradable microsphere/scaffold composite based on the synthetic polymer poly(propylene fumarate) (PPF) holds promise as a scaffold for cell growth and sustained delivery vehicle for growth factors for bone regeneration. The objective of the current work was to investigate the in vitro release and in vivo bone forming capacity of this microsphere/scaffold composite containing bone morphogenetic protein-2 (BMP-2) in combination with autologous bone marrow stromal cells (BMSCs) in a goat ectopic implantation model. Three composites consisting of 0, 0.08, or 8??g BMP-2?per mg of poly(lactic-co-glycolic acid) microspheres, embedded in a porous PPF scaffold, were combined with either plasma (no cells) or culture-expanded BMSCs. PPF scaffolds impregnated with a BMP-2 solution and combined with BMSCs as well as empty PPF scaffolds were also tested. The eight different composites were implanted subcutaneously in the dorsal thoracolumbar area of goats. Incorporation of BMP-2–loaded microspheres in the PPF scaffold resulted in a more sustained in vitro release with a lower burst phase, as compared to BMP-2–impregnated scaffolds. Histological analysis after 9 weeks of implantation showed bone formation in the pores of 11/16 composites containing 8??g/mg BMP-2–loaded microspheres with no significant difference between composites with or without BMSCs (6/8 and 5/8, respectively). Bone formation was also observed in 1/8 of the BMP-2–impregnated scaffolds. No bone formation was observed in the other conditions. Overall, this study shows the feasibility of bone induction by BMP-2 release from microspheres/scaffold composites.

Kempen, Diederik H.R.; Kruyt, Moyo C.; Lu, Lichun; Wilson, Clayton E.; Florschutz, Anthony V.; Yaszemski, Michael J.; Dhert, Wouter J.A.

2009-01-01

151

SDO Provides First Sightings of How a CME Forms  

NASA Video Gallery

Solar scientists have long known that at the heart of the great explosions of solar material that shoot off the sun -- known as coronal mass ejections or CMEs – lies a twisted kink of magnetic fields known as a flux rope. But no one has known when or where they form. Now, for the first time, NASA's Solar Dynamics Observatory as captured a flux rope in the very act of formation. Credit: NASA's Goddard Space Flight Center

gsfcvideo

2013-01-30

152

Temporal & Spatial Evolution of a Modeled CME Shock and Post-shock Compression  

NASA Astrophysics Data System (ADS)

We studied the temporal and spatial evolution of a modeled Coronal Mass Ejection (CME) driven shock and it's post-shock compression. Our goal has been to understand how the shock and the post-shock compression, as a whole with it's typical geometrical features, evolve over real time in different directions. We investigated how ?_Bn (the angle between the shock normal and the upstream magnetic field), Vs (shock velocity), Ms (Sonic Mach number), Ma (Alfven Mach number) evolve in real time at different locations on the shock and the post-shock surface. To do this, we used Rankine-Hugoniot (R-H) shock conditions of a 3D MHD shock and compared it with the other popular shock defining parameters. We also comment on the discrepancies and consequences on our observations. The CME has been initiated and then evolved in the lower solar corona with the help of Space Weather modeling Framework with a Titov- Demoulin (TD) type flux rope.

Das, I.; Opher, M.; Evans, R. M.; Gombosi, T. I.

2009-12-01

153

Thyroid function testing in eastern Nepal and the impact of CME on subsequent requests.  

PubMed

This study reveals 1 year's experience of the introduction of thyroid function tests (TFT) in B P Koirala Institute of Health Sciences (BPKIHS), a Medical University situated in eastern Nepal. These were performed on theadvice of doctors working in this region. The rational TFT advice by the medical practitioners was evaluated according to how closely the advice was in line with the algorithms recommended in the textbooks. Only about 14% of the TFT advice followed some rational strategy. A retrospective analysis showed that rational TFT advice could have reduced the cost of a TFT investigation to 43.11% without altering the patient management and disease outcome. Continuing medical education (CME) lectures arranged for a limited number of doctors were found to improve the quality of the subsequentTFT advising pattern. This emphasizes the importance of CME while introducing a costly laboratory test panel (e.g.TFT, lipid profile) needing a strategic approach. PMID:11444339

Baral, N; Koner, B C; Lamsal, M; Niraula, I; Dhungel, S

2001-07-01

154

Analysis of the 3D Structure and Velocity of a CME on 2 January 2008  

NASA Astrophysics Data System (ADS)

We perform an analysis of the 3D structure and velocity of a CME (coronal mass ejection) ejected on 2 January 2008. The event was imaged by both STEREO A and B spacecraft (mutual separation of ˜44°), providing polarized images of the event from two different points of view. To obtain information on the 3D structure of the CME from polarized images, a polarization technique (Moran & Davila, Science 305, 66, 2003) is applied. Aided by this method, we have constructed topographical maps which show the height of the various event features from the plane of the sky (i.e. toward or away from the observer) and have dinamically analyzed and compared the real and projected on the plane of the sky velocities.

López, F. M.; Cremades, H.

155

End-to-End Observations and Modeling of the 17-21 January 2010 CME/ICME  

NASA Astrophysics Data System (ADS)

On 17 January 2010, before it rotated onto the Earth-facing disk and produced a series of M-class X-ray flares, active region 11041 was associated with an energetic CME with a coronal wave and dimming, radio type II and III emission. During launch the CME revealed an unusual circular profile viewed from STEREO-B with EUVI and extending into the COR1 field. It was also observed over the southeast limb from SOHO EIT and LASCO from which it appeared as a partial halo. The views from STEREO and SOHO near the Sun and HI-A and SMEI at 1 AU suggest that at least part of the CME traveled toward STEREO-B, where a small magnetic cloud was observed on 21 January. The importance of this event lies in the multiwavelength observations with high time cadences of near-limb observations of a CME, its manifestations in the low corona, its passage through the heliosphere and its appearance as an ICME/magnetic cloud in-situ at STEREO-B 3.5 days later. This event permits us to study the origin and driving of the wave because the flanks of the CME and its relationship to the wave can be studied in detail. Our interpretation is that the wave is initially driven by the CME and then becomes freely propagating after the CME lateral expansion ends. Several models are used to understand the 3-D geometry and propagation of the CME, and two flux rope models are compared with the launch observations and magnetic field orientations.

Webb, D. F.; Cliver, E. W.; Nitta, N. V.; Attrill, G. D.; Marubashi, K.; Howard, T. A.; Tappin, J.; Jackson, B. V.

2010-12-01

156

The ModelAssembler Community Modeling Environment (MA-CME): Expanded Access to Advanced Seismic Computation  

NASA Astrophysics Data System (ADS)

We introduce MA-CME, an open-source environment for all PCs, Macs, and workstations that configures advanced seismic modeling runs. It is intended for use by seismologists, engineers, and students. The environment combines geologic and geotechnical data sets with gridding, modeling, and output specifications into portal packs for execution on standalone workstations, clusters, and mega-facilities such as Sun Grid. A tutorial interface helps the user scale the grid to the facilities available, from small test runs to efforts requiring major resources. The input geologic data are kept in open, editable forms to promote the creation of models for new areas, the regional extension of existing grids, and the detailing of critical features within current models. MA-CME currently drives computations with the E3D and the open-source E3D/CODE3 advanced simulation platforms; additional platforms will be added. The ability of MA-CME to configure computations at a range of scales and model complexity is intended to promote wide use of advanced seismic modeling. Wide community use may lead to breakthrough insights into how geology controls earthquake ground motion. Advanced seismic modeling platforms, coupled with increasing availability of faster clusters, have rapidly improved the realism of such deterministic simulations. Yet the number of people able to configure and successfully run simulations through complex geology has not grown. Ground-motion simulations have been published only for a few scenarios in a limited number of urban areas. MA-CME has been used to configure simulations to 2-Hz frequency for the Reno and Las Vegas, Nevada; Grenoble, France; and Wellington, New Zealand regions including multiple basins, detailed geotechnical maps, and attenuation. The package is freely available on the web. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Louie, J. N.; Larsen, S.

2006-12-01

157

CME on Oct. 21, 2011 Caused Red Aurora in U.S.  

NASA Video Gallery

The SOlar Heliospheric Observatory (SOHO) captured this "coronograph" – so-called because the images block the sun, and only show the sun's atmosphere, or corona. The coronal mass ejection (CME) that caused aurora to appear on the evening of October 24th begins when the counter in the lower left hand hits October 22, 1:36 (which translates to October 21, 9:36 PM ET).

Holly Zell

2011-10-25

158

The "Twin-CME" Scenario and Large Solar Energetic Particle Events in Solar Cycle 23  

NASA Astrophysics Data System (ADS)

Energetic particles in large solar energetic particle (SEP) events are a major concern for space weather. Recently, Li et al. proposed a "twin-CME" scenario for ground-level events. Here we extend that study to large SEP events in solar cycle 23. Depending on whether preceding coronal mass ejections (CMEs) within 9 hr exist and whether ions >10 MeV nucleon-1 exceed 10 pfu, we categorize fast CMEs with speed >900 km s-1 and width >60° from the western hemisphere source regions into four groups: groups I and II are "twin" and single CMEs that lead to large SEPs; groups III and IV are "twin" and single CMEs that do not lead to large SEPs. The major findings of this paper are: first, large SEP events tend to be "twin-CME" events. Of 59 western large SEP events in solar cycle 23, 43 are "twin-CME" (group I) events and 16 are single-CME (group II) events. Second, not all "twin CMEs" produced large SEPs: 28 twin CMEs did not produce large SEPs (group III events). Some of them produced excesses of particles up to a few MeV nucleon-1. Third, there were 39 single fast CMEs that did not produce SEPs (group IV events). Some of these also showed an excess of particles up to a few MeV nucleon-1. For all four groups of events, we perform statistical analyses on properties such as the angular width, the speed, the existence of accompanying metric type II radio bursts, and the associated flare class for the main CMEs and the preceding CMEs.

Ding, Liuguan; Jiang, Yong; Zhao, Lulu; Li, Gang

2013-01-01

159

Evolution of CME Magnetic Field from the Sun to 1 AU  

NASA Astrophysics Data System (ADS)

Theoretical modeling of the dynamics of coronal mass ejections (CMEs) has progressed to the point where calculated CME acceleration and speed can be quantitatively compared with observed data (e.g., TRACE, MK3, and C1--C2 data). However, the coronal magnetic fields underlying CMEs and their evolution have not been accurately observed. Nevertheless, the magnetic fields of CMEs are indirectly known by in situ measurements of their presumed interplanetary counterparts. Anticipating improved future measurements and the increasing importance of the CME phenomenon in terms of Sun-Earth connection, we investigate the magnetic fields of CMEs and their evolution to 1 AU. For this purpose, we use a flux-rope model of CMEs that has been extensively tested against observed CMEs with good agreement: (1) we will construct an ensemble of equilibrium flux ropes imbedded in a range of overlying coronal magnetic field; (2) we then allow the flux ropes to erupt and propagate to 1 AU through the corona and the interplanetary medium. We calculate the initial magnetic field of a CME based on its geometrical size (e.g., using the length of a magnetic neutral line obtained from magnetogram data as a proxy for the footpoint separation distance). For various scenarios with or without injection of poloidal magnetic flux into the initial flux rope, we quantitatively determine the range of coronal magnetic field that yields realistic CME dynamics within 30 Rsun and that results in magnetic fields at 1 AU that are consistent with those of observed magnetic clouds. We discuss predicted magnetic field signatures in the photosphere, the corona, and at 1 AU for a number of distinct scenarios. Work supported by ONR and NASA

Chen, J.

2003-12-01

160

The Dependence of Characteristic Times of Gradual SEP Events on Their Associated CME Properties  

NASA Astrophysics Data System (ADS)

It is generally believed that coronal mass ejections CMEs are the drivers of shocks that accelerate gradual solar energetic particles SEPs One might expect that the characteristics of the SEP intensity time profiles observed at 1 AU are determined by properties of the associated CMEs such as the radial speed and the angular width Recently Kahler statistically investigated the characteristic times of gradual SEP events observed from 1998-2002 and their associated coronal mass ejection properties Astrophys J 628 1014--1022 2005 Three characteristic times of gradual SEP events are determined as functions of solar source longitude 1 T 0 the time from associated CME launch to SEP onset at 1 AU 2 T R the rise time from SEP onset to the time when the SEP intensity is a factor of 2 below peak intensity and 3 T D the duration over which the SEP intensity is within a factor of 2 of the peak intensity However in his study the CME speeds and angular widths are directly taken from the LASCO CME catalog In this study we analyze the radial speeds and the angular widths of CMEs by an ice-cream cone model and re-investigate their correlationships with the characteristic times of the corresponding SEP events We find T R and T D are significantly correlated with radial speed for SEP events in the best-connected longitude range and there is no correlation between T 0 and CME radial speed and angular width which is consistent with Kahler s results On the other hand it s found that T R and T D are also have

Pan, Z. H.; Wang, C. B.; Xue, X. H.; Wang, Y. M.

161

White Light and Radio Emission of CME-Shocks: their Evolution in the Interplanetary Medium  

NASA Astrophysics Data System (ADS)

We analysed fast Coronal Mass Ejections (CMEs) driving shocks close to the solar surface and their evolution in the interplanetary (IP) medium. For each event we derived the CME kinematics and the shock strength from coronograph images, and the shock speeds in the IP medium from their type II radio burst emissions. We studied these events with an analytical model to illuminate their IP evolution.

Ontiveros, V.; Corona-Romero, P.; Gonzalez-Esparza, A.; Aguilar-Rodriguez, E.; Vourlidas, A.

2010-12-01

162

Kinematic analysis and comparison of the CME and its related EIT wave for January 10, 2010 event  

NASA Astrophysics Data System (ADS)

EIT wave, typically appearing as a diffuse brightening propagating across the Sun, is one of the major discoveries of the Extreme ultraviolet Imaging Telescope (EIT) on SOHO. But the physical nature of the so-called EIT wave is strongly debated. In order to understand the relationship between the EIT wave and its related Coronal mass ejection (CME), we investigate the morphology and kinematics of the CME-EIT wave event happened on January 10, 2010. Using the observations of SECCHI/EUVI, SECCHI/COR1 and SECCHI/COR2 onboard the STEREO-B, we track the shape and movements of the CME fronts along different radial directions to the distance of about 15 solar radii; While for the EIT wave, we determine the propagation of the wave front on the solar surface along different propagation directions. Our tracking results demonstrate that the CME front propagation is much faster than the propagation of the EIT wave on the surface. While this CME exhibits deceleration during its moving out, the EIT wave propagates at nearly constant speed. We also compare their propagation speeds to the characteristic speeds, and find out that both the CME and the EIT wave propagate beyond and with the fast-mode speed.

Zhao, X.; Wu, S.; Wang, A.; Vourlidas, A.

2010-12-01

163

Assessing the effectiveness of a Grand Rounds CME activity for health-care professionals.  

PubMed

The Lymphoma Research Foundation offers Grand Rounds continuing medical education (CME) activities on specific issues related to advances in the management of patients with lymphoma. The 2012 activity comprised interactive case studies presented by local lymphoma experts. A case-based survey was designed to assess whether the management choices of program participants are consistent with the evidence-based content of the CME activity. This survey was administered to participants 1 month after completion of the CME activity and also to a control group who did not participate in the educational program. Participants were more aware of the epidemiology of CD20-positive tumors than were controls and were more likely to appropriately diagnose primary mediastinal large B cell lymphoma (PMBCL), use evidence-based second-line therapy for PMBCL, and properly manage a patient with classic Hodgkin lymphoma that did not respond to standard therapy. Participants were also more confident than controls in their ability to interpret histology and cytogenetic testing for selecting an optimal treatment. PMID:23801053

Glauser, Terry Ann; Nevins, P Holder; Williamson, J Chad; Tomlinson, Brian

2013-09-01

164

Magnetic Geometry and Dynamics of the Fast CME of 1997 September 9  

NASA Astrophysics Data System (ADS)

A coronal mass ejection (CME) was observed on 1997 September 9 by the MLSO Mark III K-coronameter (MK3) and by the LASCO C2/C3 and EIT instruments onboard the SOHO spacecraft. Magnetograms and EIT images obtained on days leading up to the eruption show a neutral line that appears to correspond to the site of the eruption. H? images show the presence of a filament along the neutral line which subtends an angle of approximately 45(deg) with the local north-south meridional direction. Taken together, the data from these instruments provide a comprehensive, beginning-to-end record of the event within the 32 R_sun field of view. The motion of several features are tracked through the fields of view of MK3, C2, and C3. The CME exhibits the previously identified morphological features and dynamical properties consistent with those of an erupting magnetic flux rope. The LASCO images and magnetograms indicate that the flux rope axis was aligned with the neutral line approximately two days behind the west limb. Its apparent orientation provides an oblique view of an erupting flux rope, a view that has not been discussed previously. A theoretical flux rope model is used to understand the observed CME dynamics. Synthetic coronagraph images based on the model flux rope are constructed. Work supported by ONR, NASA, and NSF.

Chen, J.; Santoro, R. A.; Krall, J.; Howard, R. A.; Duffin, R.; Moses, J. D.; Brueckner, G. E.; Darnell, J. A.; Burkepile, J.

1999-05-01

165

The Asymmetrical Eruption of a Quiescent Filament and Associated Halo CME  

NASA Astrophysics Data System (ADS)

We will present detailed observations of the asymmetrical eruption of a large quiescent filament on 24 November 2002, which was followed by a two-ribbon flare, three coronal dimmings, endpoint brightenings, and a very fast halo-type coronal mass ejection (CME). Before the eruption, the filament lay along the main neutral line (MNL) underneath a single-arcade helmet streamer with a simple bipolar configuration. However, photospheric magnetic fields on both sides of the filament showed an asymmetrical distribution, and the filament and MNL were not located just at the center of the streamer base but were closer to the eastern leg of the streamer arcade. Therefore, instead of erupting along the streamer's symmetrical axis, the filament showed a nonradial and asymmetrical eruption. It lifted from the eastern flank of the streamer arcade to impact the western leg directly, leading to an asymmetrical CME that expanded westward; eventually the streamer was disrupted significantly. Accordingly, the opposite-polarity coronal dimmings at both sides of the filament forming in the eruption also showed an asymmetrical area distribution. We thus assume that the streamer arcade could guide the filament at the early eruption phase but failed to restrain it later. Consistent with previous results, these observations suggest that the global background magnetic field can impose additional action on the initial eruption of the filament and CME, as well as the dimming configuration.

Yang, J.; Jiang, Y.; Yang, B.; Zheng, R.; Yang, D.; Hong, J.; Li, H.; Bi, Y.

2012-07-01

166

RECONNECTIONLESS CME ERUPTION: PUTTING THE ALY-STURROCK CONJECTURE TO REST  

SciTech Connect

We demonstrate that magnetic reconnection is not necessary to initiate fast Coronal mass ejections (CMEs). The Aly-Sturrock conjecture states that the magnetic energy of a given force-free boundary field is maximized when the field is open. This is problematic for CME initiation because it leaves little or no magnetic energy to drive the eruption, unless reconnection is present to allow some of the flux to escape without opening. Thus, it has been thought that reconnection must be present to initiate CMEs. This theory has not been subject to rigorous numerical testing because conventional magnetohydrodynamics (MHD) numerical models contain numerical diffusion, which introduces uncontrolled numerical reconnection. We use a quasi-Lagrangian simulation technique to run the first controlled experiments of CME initiation in the complete lack of reconnection. We find that a flux rope confined by an arcade, when twisted beyond a critical amount, can escape to an open state, allowing some of the surrounding arcade to shrink, and releasing magnetic energy from the global field. This mechanism includes a true ideal MHD instability. We conclude that reconnection is not a necessary trigger for fast CME eruptions.

Rachmeler, L. A. [University of Colorado at Boulder, Boulder, CO, 80304-0391 (United States); DeForest, C. E. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Kankelborg, C. C. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)], E-mail: laurel.rachmeler@colorado.edu

2009-03-10

167

Breech delivery.  

PubMed

Fetuses that present by the breech are at increased risk of trauma and hypoxia during delivery. The threshold for Caesarean section for breech presentation had been low for several years. The result of the term breech trial confirms that planned Caesarean section is the best method of delivering the singleton frank or complete breech at term. The best mode of delivery for the pre-term breech is less clear. Vaginal breech delivery will be unavoidable in certain circumstances and it is therefore important to be adept with the techniques of vaginal breech delivery. The atraumatic technique of delivery of the baby presenting by the breech at times of Caesarean section is similar to that of assisted vaginal breech delivery. The number of vaginal breech deliveries is falling, and regular teaching using video clips or practising with mannequins will be necessary to preserve the skills of vaginal breech delivery. PMID:11866495

Mukhopadhyay, Sambit; Arulkumaran, Sabaratnam

2002-02-01

168

Synthesis of an organogallium(I) compound [Ga(CH 2CMe 2Ph)] n with EPR spectral evidence for gallium clusters  

Microsoft Academic Search

The organogallium(I) compound [Ga(CH2CMe2Ph)]n has been prepared by the reduction of Ga(CH2CMe2Ph)2Cl by using either sodium or lithium with naphthalene in THF. The yellow dihydronaphthalene gallium(III) intermediate M2{C10H8[Ga(CH2CMe2Ph)2Cl]2} initially formed at ?78°C but then decomposed at higher temperatures to form [Ga(CH2CMe2Ph)]n, Ga(CH2CMe2Ph)3 and MCl. EPR spectra, which were recorded as the two yellow intermediates Na2{C10H8[Ga(CH2CMe2R)2Cl]2} (R=Ph, Me) decomposed, indicated the

O. T. Beachley Jr.; Matthew J. Noble; Robert D. Allendoerfer

1999-01-01

169

Hydrogen bonding interpolymer complex formation and study of its host-guest interaction with cyclodextrin and its application as an active delivery vehicle.  

PubMed

Interpolymer complex formation through hydrogen bonding has been investigated between two polymers: poly(acrylamide) (PAAm) and poly(vinyl alcohol) (PVA). The differential properties of the interpolymer complex with varying molecular weights of PVA have been studied by taking three different molecular weights of PVA. Furthermore, the host-guest interaction between the interpolymer complexes prepared and ?-cyclodextrin (?-CD) has also been studied in detail. PAAm can form interpolymer complexes with PVA because of a cooperative hydrogen bonding interaction. The addition of ?-CD to a dilute aqueous solution of PAAm-PVA results in a competition between interpolymer hydrogen bonding and host-guest interactions. In this article, we have tried to decipher the complex chemistry that occurs in the microheterogeneous solution. The PAAm-PVA binary system and the PAAm-PVA-?-CD ternary systems have been well characterized by using a fluorescent probe, coumarin-102. Dynamic light scattering (DLS), Fourier transform infrared (FTIR), fluorescence microscopy, and time-resolved fluorescence studies have been performed to substantiate steady-state fluorescence experiments. The results indicate the occurrence of a competitive interaction between the hydrogen bonding of the interpolymer complexes and the host-guest interaction with ?-CD, whereby the later predominates. It is probable that the hydrophobic cavity of ?-CD is threaded with linear polymers, thus forming a macromolecular supraassembly. It has also been concluded that PAAm preferentially interacts with ?-CD by compromising its interaction with PVA. The enhanced deposition and retention of actives with this system was studied with a single species regrowth assay, antibacterial efficacy and the cell viability were studied using the live-dead staining protocol. This therefore opens new avenues in the targeted delivery of actives. PMID:23373846

Das, Somnath; Joseph, Maya T; Sarkar, Deboleena

2013-02-01

170

Stream Structure and Coronal Sources of the Solar Wind During the May 12th, 1997 CME  

NASA Astrophysics Data System (ADS)

We report on our efforts to model the ambient solar wind out to 1AU around the time of the May 12th 1997 Halo CME and to identify its coronal source regions. We use three different coupled coronal/solar wind models to accomplish this: the simple physics and empirical based Wang-Sheeley-Arge (WSA) model, the advanced 3-D Magnetohydrodynamic (MHD) ENLIL solar wind model coupled to results generated by the SAIC 3-D steady state MHD coronal model, and the magnetostatic coronal component of the WSA model coupled to the ENLIL model. In addition, the sheath region of the ICME event is simulated using the ENLIL 3D MHD code by launching an over pressured hydrodynamic cloud with speed, extent, duration, and position determined by the Zhao Cone model [Zhao et al., JGR, 2001]. The simulation results generated by the different model combinations are then compared with the WIND satellite observations near Earth as well as with each other. We find that all three coupled models describe the ambient solar wind stream structure around the time of the May 12th, 1997 CME generally well, except for the ejecta itself, as evidenced by the overall good agreement between the solar wind observations at L1 and model simulation results, which are themselves in surprisingly good agreement with each other. The ENLIL model successfully replicates the ambient solar wind plus the shock and sheath region of the ICME when a simple over pressured hydrodynamic cloud is applied. Our results suggest that the source of the high-stream that followed the CME originated from a coronal hole extension located south of the Sun's equator.

Arge, C. N.; Odstrcil, D.; Luhmann, J. G.

2003-12-01

171

The Width of a Solar Coronal Mass Ejection and the Source of the Driving Magnetic Explosion: A Test of the Standard Scenario for CME Production  

NASA Astrophysics Data System (ADS)

We show that the strength (BFlare) of the magnetic field in the area covered by the flare arcade following a CME-producing ejective solar eruption can be estimated from the final angular width (Final ?CME) of the CME in the outer corona and the final angular width (?Flare) of the flare arcade: BFlare~1.4[(Final ?CME)/?Flare2 G. We assume (1) the flux-rope plasmoid ejected from the flare site becomes the interior of the CME plasmoid; (2) in the outer corona (R>2 Rsolar) the CME is roughly a ``spherical plasmoid with legs'' shaped like a lightbulb; and (3) beyond some height in or below the outer corona the CME plasmoid is in lateral pressure balance with the surrounding magnetic field. The strength of the nearly radial magnetic field in the outer corona is estimated from the radial component of the interplanetary magnetic field measured by Ulysses. We apply this model to three well-observed CMEs that exploded from flare regions of extremely different size and magnetic setting. One of these CMEs was an over-and-out CME, that is, in the outer corona the CME was laterally far offset from the flare-marked source of the driving magnetic explosion. In each event, the estimated source-region field strength is appropriate for the magnetic setting of the flare. This agreement (1) indicates that CMEs are propelled by the magnetic field of the CME plasmoid pushing against the surrounding magnetic field; (2) supports the magnetic-arch-blowout scenario for over-and-out CMEs; and (3) shows that a CME's final angular width in the outer corona can be estimated from the amount of magnetic flux covered by the source-region flare arcade.

Moore, Ronald L.; Sterling, Alphonse C.; Suess, Steven T.

2007-10-01

172

CME mass evolution derived from stereoscopic observations of STEREO/SECCHI instruments COR1 and COR2  

NASA Astrophysics Data System (ADS)

The STEREO mission consists of two nearly identical spacecraft STEREO-A and STEREO-B, which observe simultaneously the Sun from two different vantage points. We use observations from both coronagraphs, COR1 and COR2 of the SECCHI instrument suite aboard STEREO-A and STEREO-B, to derive the CME mass evolution for a height range from 1.4 to 15 RSun. Due to the fact that we have observations from two different vantage points, we measure not only the projected mass but can estimate the 'true' CME mass evolution with height. We developed a fit function, which considers the mass increase based on the geometry of the instrument (mass hidden behind the occulter) and a possible 'real' mass increase with height. The fit parameters are compared with characteristic CME quantities.

Bein, B.; Temmer, M.; Vourlidas, A.; Veronig, A.

2012-04-01

173

Synthesis and Characterization of a Linear [Mn3(O2CMe)4(py)8]2+ Complex  

PubMed Central

Two new compounds that consist of the linear trinuclear manganese(II) cation [Mn3(O2CMe)4(py)8]2+ cocrystallizing with different counteranions (I3?, [1]; ClO4?, [2]) are reported. Complex 1 was prepared from the reaction of [Mn(O2CMe)2] · 4H2O with I2 in MeCO2H/py, whereas complex 2 was isolated from the reaction of [Mn3O(O2CMe)6(py)3] · py with [Mn(ClO4)2] · 6H2O in MeCN/py. The crystal structures of both compounds were determined by single crystal X-ray crystallography. Magnetic susceptibility studies that were performed in microcrystalline powder of 1 in the 2–300?K range revealed the presence of antiferromagnetic exchange interactions that resulted in an S = 5/2 ground spin state.

Moushi, Eleni E.; Kizas, Christos; Nastopoulos, Vassilios; Tasiopoulos, Anastasios J.

2010-01-01

174

The Possible Magnetospheric, Ionospheric, and Thermospheric Response to the 1859 Carrington CME.  

NASA Astrophysics Data System (ADS)

The 1859 Carrington event is interesting because of the possible strength of the magnetic field and incredibly strong solar wind ram pressure. This is because the coronal mass ejection only took 18 hours to propagate from the Sun to the Earth, implying a speed of over 1700 km/s, with associated magnetic fields of over 200 nT. Using the space weather modeling framework (SWMF) we have simulated the possible response of the near-Earth space environment to a coronal mass ejection (CME) which took 18 hours to travel from the Sun to the Earth. We find that the magnetosphere was compressed to within 4 Earth Radii on the dayside and within geosynchronous orbit at all local times. We further find that the timings of the magnetospheric compressions align quite well with the magnetic field measurements of the 1859 storm. We will present results of the ionospheric cross polar cap potential, thermospheric densities and temperatures, ring current strength, and other magnetospheric, ionospheric, and thermospheric quantities through out the CME.

Ridley, A. J.; de Zeeuw, D.; Sokolov, I.; Toth, G.; Clauer, C. R.; Manchester, W.; Gombosi, T.; Powell, K.

2004-05-01

175

Ion acceleration at CME-driven shocks near the Earth and the Sun  

NASA Astrophysics Data System (ADS)

We compare the behavior of heavy ion spectra during an Energetic Storm Particle (ESP) event that exhibited clear evidence of wave excitation with that observed during an intense, large gradual Solar Energetic Particle (SEP) event in which the associated <0.2 MeV/nucleon ions are delayed >12 hr. We interpret that the ESP event is an example of the first-order Fermi acceleration process where enhancements in the magnetic field power spectral densities around local ion cyclotron frequency ?pc indicate the presence of Alfvén waves excited by accelerated protons streaming away from the in-situ interplanetary shock. The softening or unfolding of the CNO energy spectrum below ~200 keV/nucleon and the systematic organization of the Fe and O spectral roll-overs with the E/q ratio during the ESP event are likely due to M/Q-dependent trapping and scattering of the heavy ions by the proton-excited waves. Based on striking similarities in the spectral behavior observed upstream of both, the ESP and the SEP event, we suggest that coupling between proton-generated Alfvén waves and energetic ions is also operating at the distant CME shock during the large, gradual SEP event, thereby providing us with a new, powerful tool to remotely probe the roles of shock geometries and wave-particle interactions at near-Sun CME-driven shocks.

Desai, Mihir; Dayeh, Maher; Ebert, Robert; Smith, Charles; Mason, Glenn; Li, G.

2012-11-01

176

The Recovery of CME-Related Dimmings and the ICME's Enduring Magnetic Connection to the Sun  

NASA Astrophysics Data System (ADS)

It is generally accepted that transient coronal holes (TCHs, dimmings) correspond to the magnetic footpoints of CMEs that remain rooted in the Sun as the CME expands out into the interplanetary space. However, the observation that the average intensity of the 12 May 1997 dimmings recover to their pre-eruption intensity in SOHO/EIT data within 48 hours, whilst suprathermal unidirectional electron heat fluxes are observed at 1 AU in the related ICME more than 70 hours after the eruption, leads us to question why and how the dimmings disappear whilst the magnetic connectivity is maintained. We also examine two other CME-related dimming events: 13 May 2005 and 6 July 2006. We study the morphology of the dimmings and how they recover. We find that, far from exhibiting a uniform intensity, dimmings observed in SOHO/EIT data have a deep central core and a more shallow extended dimming area. The dimmings recover not only by shrinking of their outer boundaries but also by internal brightenings. We quantitatively demonstrate that the model developed by Fisk and Schwadron ( Astrophys. J. 560, 425, 2001) of interchange reconnections between “open” magnetic field and small coronal loops is a strong candidate for the mechanism facilitating the recovery of the dimmings. This process disperses the concentration of “open” magnetic field (forming the dimming) out into the surrounding quiet Sun, thus recovering the intensity of the dimmings whilst still maintaining the magnetic connectivity to the Sun.

Attrill, G. D. R.; van Driel-Gesztelyi, L.; Démoulin, P.; Zhukov, A. N.; Steed, K.; Harra, L. K.; Mandrini, C. H.; Linker, J.

2008-11-01

177

Delivery methods for LVSD systems  

NASA Astrophysics Data System (ADS)

In this paper we present formats and delivery methods of Large Volume Streaming Data (LVSD) systems. LVSD systems collect TBs of data per mission with aggregate camera sizes in the 100 Mpixel to several Gpixel range at temporal rates of 2 - 60 Hz. We present options and recommendations for the different stages of LVSD data collection and delivery, to include the raw (multi-camera) data, delivery of processed (stabilized mosaic) data, and delivery of user-defined region of interest windows. Many LVSD systems use JPEG 2000 for the compression of raw and processed data. We explore the use of the JPEG 2000 Interactive Protocol (JPIP) for interactive client/server delivery to thick-clients (desktops and laptops) and MPEG-2 and H.264 to handheld thin-clients (tablets, cell phones). We also explore the use of 3D JPEG 2000 compression, defined in ISO 15444-2, for storage and delivery as well. The delivery of raw, processed, and region of interest data requires different metadata delivery techniques and metadata content. Beyond the format and delivery of data and metadata we discuss the requirements for a client/server protocol that provides data discovery and retrieval. Finally, we look into the future as LVSD systems perform automated processing to produce "information" from the original data. This information may include tracks of moving targets, changes of the background, snap shots of targets, fusion of multiple sensors, and information about "events" that have happened.

Kasner, James H.; Brower, Bernard V.

2011-05-01

178

The Role of the IMF in Forecasting CME-Induced Terrestrial Space Weather  

NASA Astrophysics Data System (ADS)

The interplanetary magnetic field (IMF) is the major contributor to terrestrial space weather induced by coronal mass ejections (CME). Nowcasting of these events has become quite successful. Our ability to forecast such events on significant time scales (on the order of one day), however, remains a rather elusive goal. In situ observations of the solar wind at the L1 point provide an advance warning of no more than 1 hour. The auto-correlation times of the solar wind are usually too short to enable data driven predictions with sufficient lead times. The resolution of both solar wind propagation modeling from Sun to Earth and solar remote sensing observations is insufficient to predict the CME internal structure at the level needed to predict terrestrial space weather conditions. A practical terrestrial space weather forecast for CMEs will require an integrated approach where remote sensing, modeling and in situ components work together to make the resulting framework stronger than the sum of the individual parts. In this presentation, we will concentrate on in situ observations of the IMF viewed in this context. Ultimately, our goal is to enable the development of integrated, data-driven space weather forecasting. For this, we need to understand the temporal patterns of the IMF inside CMEs at relevant time scales. To uncover these patterns we are classifying solar wind time series segments of various lengths using specially trained neural networks (Kohonen Self-Organizing Maps). We present how well our networks can classify CMEs and their subclasses as a function of the length of these time series segments and the variable types (IMF, solar wind properties) we use. Then we discuss the probability with which the future temporal development of the solar wind can be predicted using those time segment patterns. To close the presentation, we discuss how we envision to correlate our purely empirical CME time segment classifications of the IMF and solar wind measurements with remote sensing solar observations. Combining these correlations with solar wind propagation estimates could lead to probability estimates of IMF temporal developments at L1 and Earth based on remote sensing solar observations alone.

Jahn, J.; Elliott, H. A.

2009-12-01

179

C-ME: A 3D Community-Based, Real-Time Collaboration Tool for Scientific Research and Training  

PubMed Central

The need for effective collaboration tools is growing as multidisciplinary proteome-wide projects and distributed research teams become more common. The resulting data is often quite disparate, stored in separate locations, and not contextually related. Collaborative Molecular Modeling Environment (C-ME) is an interactive community-based collaboration system that allows researchers to organize information, visualize data on a two-dimensional (2-D) or three-dimensional (3-D) basis, and share and manage that information with collaborators in real time. C-ME stores the information in industry-standard databases that are immediately accessible by appropriate permission within the computer network directory service or anonymously across the internet through the C-ME application or through a web browser. The system addresses two important aspects of collaboration: context and information management. C-ME allows a researcher to use a 3-D atomic structure model or a 2-D image as a contextual basis on which to attach and share annotations to specific atoms or molecules or to specific regions of a 2-D image. These annotations provide additional information about the atomic structure or image data that can then be evaluated, amended or added to by other project members.

Kolatkar, Anand; Kennedy, Kevin; Halabuk, Dan; Kunken, Josh; Marrinucci, Dena; Bethel, Kelly; Guzman, Rodney; Huckaby, Tim; Kuhn, Peter

2008-01-01

180

43 CFR 11.42 - How does the authorized official apply the NRDAM/CME or NRDAM/GLE?  

Code of Federal Regulations, 2011 CFR

...or NRDAM/GLE? 11.42 Section 11.42 Public Lands: Interior Office of the Secretary of the Interior NATURAL RESOURCE DAMAGE ASSESSMENTS Type A Procedures § 11.42 How does the authorized official apply the NRDAM/CME or...

2011-10-01

181

43 CFR 11.42 - How does the authorized official apply the NRDAM/CME or NRDAM/GLE?  

Code of Federal Regulations, 2012 CFR

...or NRDAM/GLE? 11.42 Section 11.42 Public Lands: Interior Office of the Secretary of the Interior NATURAL RESOURCE DAMAGE ASSESSMENTS Type A Procedures § 11.42 How does the authorized official apply the NRDAM/CME or...

2012-10-01

182

Role of solar X-ray flares and CME in the E region ionosphere of Mars: MGS observations  

NASA Astrophysics Data System (ADS)

The relationship of the solar flare and the Coronal Mass Ejection (CME) with the ionosphere is a key problem in all planetary atmospheres. Earth is the only planet where ground based observations can be used to study this relationship on a continuous basis. In this paper we have used radio occultation data obtained from Mars Global Surveyor (MGS) for the period of 12-18 May, 2005 to address the responses of X-ray flare and CME in Total Electron Content (TEC) of E region ionosphere of Mars during a violent solar event that occurred on 13th May. It was found that the TEC increased by factors of 6 in the E region ionosphere of Mars during this flare. The response of mass ejections from the Sun's corona is registered in the E region ionosphere of Mars after ˜38 h. Our results suggest that TEC can increase by factor of ˜3.5-4.5 during the arrival of CME on Mars. This increase in TEC can be attributed to ionization by energetic particles associated with magnetic storms. We report that shocked waves driven by CME compressed the magnetosheath of Mars by 15 km during the magnetic storms.

Haider, S. A.

2012-04-01

183

C-ME: a 3D community-based, real-time collaboration tool for scientific research and training.  

PubMed

The need for effective collaboration tools is growing as multidisciplinary proteome-wide projects and distributed research teams become more common. The resulting data is often quite disparate, stored in separate locations, and not contextually related. Collaborative Molecular Modeling Environment (C-ME) is an interactive community-based collaboration system that allows researchers to organize information, visualize data on a two-dimensional (2-D) or three-dimensional (3-D) basis, and share and manage that information with collaborators in real time. C-ME stores the information in industry-standard databases that are immediately accessible by appropriate permission within the computer network directory service or anonymously across the internet through the C-ME application or through a web browser. The system addresses two important aspects of collaboration: context and information management. C-ME allows a researcher to use a 3-D atomic structure model or a 2-D image as a contextual basis on which to attach and share annotations to specific atoms or molecules or to specific regions of a 2-D image. These annotations provide additional information about the atomic structure or image data that can then be evaluated, amended or added to by other project members. PMID:18286178

Kolatkar, Anand; Kennedy, Kevin; Halabuk, Dan; Kunken, Josh; Marrinucci, Dena; Bethel, Kelly; Guzman, Rodney; Huckaby, Tim; Kuhn, Peter

2008-02-20

184

Particle acceleration and transport at an oblique CME-driven shock  

NASA Astrophysics Data System (ADS)

In gradual solar energetic particle (SEP) events, protons and heavy ions are often accelerated to >100 MeV/nucleon at a CME-driven shock. In this work, we study particle acceleration at an oblique shock by extending our earlier particle acceleration and transport in heliosphere (PATH) code to include shocks with arbitrary ?BN, where ?BN is the angle between the upstream magnetic field and the shock normal. Instantaneous particle spectra at the shock front are obtained by solving the transport equation using the total diffusion coefficient ?, which is a function of the parallel diffusion coefficient ?? and the perpendicular diffusion coefficient ??. In computing ?? and ??, we use analytic expressions derived previously. The particle maximum energy at the shock front as a function of time, the time intensity profiles and particle spectra at 1 AU for five ?BN's are calculated for an example shock.

Li, G.; Shalchi, A.; Ao, X.; Zank, G.; Verkhoglyadova, O. P.

2012-03-01

185

Quantitative Imaging of the Solar Wind: CME Mass Evolution and the Interplanetary Magnetic Flux Balance  

NASA Astrophysics Data System (ADS)

We recently developed post-processing techniques for heliospheric images from the STEREO spacecraft; the new data sets enable, for the first time, quantitative photometric studies of evolving wind features at distances up to 1 A.U. from the Sun. We have used the new data to trace several CMEs and magnetic disconnection events to their origins in the solar corona, and to infer the force balance and entrained magnetic flux in those features. We present recent results showing the relationship between ICME and CME anatomy, in particular the origin of an observed interplanetary flux rope and the relationship between original launched solar material and piled-up sheath material and flux in the storm at 1. A.U. We discuss implications for understanding space weather physics and predicting individual events, and point out the importance of future imaging technologies such as polarized heliospheric imaging.

DeForest, Craig

2012-05-01

186

Predicting the 1-AU passage times of CME-associated interplanetary shocks using three-dimensional simulations : Effect of the ambient solar wind  

NASA Astrophysics Data System (ADS)

We describe prediction system of the 1-AU passage times of interplanetary shock waves asso-ciated with coromal mass ejections (CMEs). This system is based on simulations of the shock propagation using a three-dimensional adaptive mesh refinement (AMR) code, which was pre-sented at last COSPAR 2008. We have improved this model by updating the simulation code, so that higher resolution simulations are possible, and by changing the explosion model of CMEs to allow the variation of the expansion of the CMEs. It was found that it was difficult for the simulation results to be agreement with the observations when difference between the CME speed and the ambient solar wind speed was small in our previous model. We simulate the ambient solar wind just before occurring CMEs, which reproduces the solar wind parameters at that time observed by ACE spacecraft. Then we input the expansion speed and occurrence position data of that CME as initial condtions for an CME model, and 3D simulation of the CME and the shock propagation is perfomed until the shock wave passes the 1-AU. We can study interaction of the CME and the ambinet solar wind in our model. In this work, we perform the simulations for some CME events, investigate an effect the ambient solar wind on the CME propagation, and discuss efficiency of the model by obtaining prediction errors.

den, Mitsue; Ogawa, Tomoya; Tanaka, Takashi; Watari, Shinichi; Yamashita, Kazuyuki

187

Advances in Drug Delivery  

NASA Astrophysics Data System (ADS)

In this article, we review critical aspects in the area of drug delivery. Specifically, delivery of siRNA, remote-controlled delivery, noninvasive delivery, and nanotechnology in drug delivery are reviewed.

Timko, Brian P.; Whitehead, Kathryn; Gao, Weiwei; Kohane, Daniel S.; Farokhzad, Omid; Anderson, Daniel; Langer, Robert

2011-08-01

188

Lamellar macular hole formation in chronic cystoid macular edema associated with retinal vein occlusion  

Microsoft Academic Search

Purpose  To report the formation of a lamellar macular hole (LMH) in four eyes with chronic cystoid macular edema (CME) associated\\u000a with retinal vein occlusion (RVO).\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We reviewed retrospectively the medical records of four patients with chronic CME associated with RVO, in whom LMH formation\\u000a was observed by a series of examinations with optical coherence tomography.\\u000a \\u000a \\u000a \\u000a \\u000a Results  All eyes showed a large

Kayoko TsukadaAkitaka Tsujikawa; Akitaka Tsujikawa; Tomoaki Murakami; Ken Ogino; Nagahisa Yoshimura

189

Twin delivery.  

PubMed

The incidence of twin pregnancy has increased worldwide over the past 10 years largely as a consequence of the assisted reproductive technologies. Issues such as intrapartum monitoring and operative interventions, especially with regard to the second twin, provide a unique challenge in labour and delivery. Epidemiological data suggest that the term twin has a threefold higher mortality rate than the singleton. It is the authors' view that many aspects of twin delivery deserve as much import as those features of twin gestations such as pre-term birth and intrauterine growth restriction that, to date, have received much of the research and clinical interest in this area. Indications for elective Caesarean section are presented, incorporating new data derived from the delivery of the term singleton breech, and implications on the timing thereof are discussed. Vaginal delivery of both twins presenting by the vertex is recommended as safe as long as guidelines for the conduct of such delivery are followed. The recommended time interval between twins as well as the use of epidural, fetal monitoring and ultrasound in the delivery room are discussed. The second twin presenting as a non-vertex presents an urgent dilemma for accoucheurs. Data suggest that internal version and breech extractions are safer than external cephalic version provided that the appropriate techniques are applied. It is revealed, however, that the use of elective Caesarean section in this group of babies has not been subject to randomized controlled studies of sufficient power to determine the best method of delivery of the second twin - particularly in the low-birth-weight baby. PMID:11866496

Barrett, J F R; Ritchie, W Knox

2002-02-01

190

Coronal Mass Ejection (CME) Activity of Low Mass M Stars as An Important Factor for The Habitability of Terrestrial Exoplanets. II. CME-Induced Ion Pick Up of Earth-like Exoplanets in Close-In Habitable Zones  

Microsoft Academic Search

Atmospheric erosion of CO2 -rich Earth-size exoplanets due to coronal mass ejection (CME)-induced ion pick up within close-in habitable zones of active M-type dwarf stars is investigated. Since M stars are active at the X-ray and extreme ultraviolet radiation (XUV) wave-lengths over long periods of time, we have applied a thermal balance model at various XUV flux input values for

Helmut Lammer; Herbert I. M. Lichtenegger; Yuri N. Kulikov; Jean-Mathias Grießmeier; N. Terada; Nikolai V. Erkaev; Helfried K. Biernat; Maxim L. Khodachenko; Ignasi Ribas; Thomas Penz; Franck Selsis

2007-01-01

191

Breech delivery  

Microsoft Academic Search

Fetuses that present by the breech are at increased risk of trauma and hypoxia during delivery. The threshold for Caesarean section for breech presentation had been low for several years. The result of the term breech trial confirms that planned Caesarean section is the best method of delivering the singleton frank or complete breech at term. The best mode of

Sambit Mukhopadhyay; Sabaratnam Arulkumaran

2002-01-01

192

Twin delivery  

Microsoft Academic Search

The incidence of twin pregnancy has increased worldwide over the past 10 years largely as a consequence of the assisted reproductive technologies. Issues such as intrapartum monitoring and operative interventions, especially with regard to the second twin, provide a unique challenge in labour and delivery. Epidemiological data suggest that the term twin has a threefold higher mortality rate than the

J. F. R. Barrett; W. Knox Ritchie

2002-01-01

193

Three-dimensional propagation of coronal mass ejections in a structured solar wind flow 2. CME launched adjacent to the streamer belt  

Microsoft Academic Search

A three-dimensional (3-D) numerical hydrodynamic model is used to investigate the evolution of coronal mass ejections (CMEs) launched at several heliographic positions into a tilted-dipole ambient solar wind (SW) flow, which is appropriate around solar activity minimum and declining phase. The CME is injected as an overpressured plasma cloud. Results show that the motion and local appearance of a CME

D. Odstrcil; V. J. Pizzo

1999-01-01

194

In Situ Heating of the 2007 May 19 CME Ejecta Detected by Stereo/PLASTIC and ACE  

NASA Astrophysics Data System (ADS)

In situ measurements of ion charge states can provide unique insight into the heating and evolution of coronal mass ejections (CMEs) when tested against realistic non-equilibrium ionization modeling. In this work, we investigate the representation of the CME magnetic field as an expanding spheromak configuration, where the plasma heating is prescribed by the choice of anomalous resistivity and the spheromak dynamics. We chose as a test case the 2007 May 19 CME observed by STEREO and ACE. The spheromak is an appealing physical model, because the location and degree of heating are fixed by the choice of anomalous resistivity and the spheromak expansion rate which we constrain with observations. This model can provide the heating required between 1.1R sun and Earth's orbit to produce charge states observed in the CME flux rope. However, this source of heating in the spheromak alone has difficulty accounting for the rapid heating to Fe8-Fe11+ at lower heights, as observed in STEREO EUVI due to the rapid radiative cooling that occurs at the high densities involved. Episodes of heating and cooling clearly unrelated to spheromak expansion are observed prior to the eruption, and presumably still play a role during the eruption itself. Spheromak heating is also not capable of reproducing the high Fe charge states (Fe16+ and higher) seen in situ exterior to the flux rope in this CME. Thus, while the spheromak configuration may be a valid model for the magnetic topology, other means of energization are still required to provide much of the rapid heating observed.

Rakowski, Cara E.; Laming, J. Martin; Lyutikov, Maxim

2011-03-01

195

CME: A 3D Community-Based, Real-Time Collaboration Tool for Scientific Research and Training  

Microsoft Academic Search

The need for effective collaboration tools is growing as multidisciplinary proteome-wide projects and distributed research teams become more common. The resulting data is often quite disparate, stored in separate locations, and not contextually related. Collaborative Molecular Modeling Environment (C-ME) is an interactive community-based collaboration system that allows researchers to organize information, visualize data on a two-dimensional (2-D) or three-dimensional (3-D)

Anand Kolatkar; Kevin Kennedy; Dan Halabuk; Josh Kunken; Dena Marrinucci; Kelly Bethel; Rodney Guzman; Tim Huckaby; Peter Kuhn; Robert Futrelle

2008-01-01

196

Tracking the momentum flux of a CME and quantifying its influence on geomagnetically induced currents at Earth  

NASA Astrophysics Data System (ADS)

We investigate a CME propagating towards Earth on 29 March 2011. This event is specifically chosen for its predominately northward directed magnetic field, so that the influence from the momentum flux onto Earth can be isolated. We focus our study on understanding how a small Earth-directed segment propagates. Mass images are created from the white-light cameras onboard STEREO which are also converted into mass height-time maps (mass J-maps). The mass tracks on these J-maps correspond to the sheath region between the CME and its associated shock front as detected by in situ measurements at L1. A time-series of mass measurements from the STEREO COR-2A instrument are made along the Earth propagation direction. Qualitatively, this mass time-series shows a remarkable resemblance to the L1 in situ density series. The in situ measurements are used as inputs into a 3D magnetospheric space weather simulation from CCMC. These simulations display a sudden compression of the magnetosphere from the large momentum flux at the leading edge of the CME and predictions are made for the time-derivative of the magnetic field (dB/dt) on the ground. The predicted dB/dt were then compared with observations from specific equatorially-located ground stations and show notable similarity. This study of the momentum of a CME from the Sun down to its influence on magnetic ground stations on Earth is presented as preliminary proof of concept, such that future attempts may try to use remote sensing to create density and velocity time-series as inputs to magnetospheric simulations.

Savani, Neel; Vourlidas, Angelos; Pullkinen, Antti

2013-04-01

197

Low Temperature Hysteretic Behavior of the Interpenetrating 3-D Network Structured [Ru2(O2CMe)4]3[Fe(CN)6] Magnet  

SciTech Connect

The low temperature hysteretic behavior between 40 mK and 4.8 K was obtained for [Ru2(O2CMe)4]3[Fe(CN)6]. The unusual constricted hysteretic behavior reported for isomorphous [Ru2(O2CMe)4]3[Cr(CN)6] was not observed. Instead, the [Ru2(O2CMe)4]3-[Fe(CN)6] exhibits a single hysteresis loop and a temperature dependence of the coercivity atypical for a ferrimagnetic ordering transition. The coercive field, constant below ~0.3 K (1.06 kOe), shows a rapid initial decrease below 1 K, to continue decreasing at a slower rate up to at least 4.8 K. In contrast to [Ru2(O2CMe)4]3[Cr(CN)6] which has antiferromagnetic coupling of the ferrimagnetic lattices, due to the reduced spin on the [FeIII(CN)6]3-, [Ru2(O2CMe)4]3[Fe(CN)6] ferromagnetic coupling of the ferrimagnetic lattices dominates for [Ru2(O2CMe)4]3[Fe(CN)6].

Haque, F. [University of Central Florida; Del barco, Enrique [University of Central Florida; Fishman, Randy Scott [ORNL; Miller, Joel S. [University of Utah

2013-01-01

198

SMEI 3D RECONSTRUCTION OF A CORONAL MASS EJECTION INTERACTING WITH A COROTATING SOLAR WIND DENSITY ENHANCEMENT: THE 2008 APRIL 26 CME  

SciTech Connect

The Solar Mass Ejection Imager (SMEI) has recorded the brightness responses of hundreds of interplanetary coronal mass ejections (CMEs) in the interplanetary medium. Using a three-dimensional (3D) reconstruction technique that derives its perspective views from outward-flowing solar wind, analysis of SMEI data has revealed the shapes, extents, and masses of CMEs. Here, for the first time, and using SMEI data, we report on the 3D reconstruction of a CME that intersects a corotating region marked by a curved density enhancement in the ecliptic. Both the CME and the corotating region are reconstructed and demonstrate that the CME disrupts the otherwise regular density pattern of the corotating material. Most of the dense CME material passes north of the ecliptic and east of the Sun-Earth line: thus, in situ measurements in the ecliptic near Earth and at the Solar-TErrestrial RElations Observatory Behind spacecraft show the CME as a minor density increase in the solar wind. The mass of the dense portion of the CME is consistent with that measured by the Large Angle Spectrometric Coronagraph on board the Solar and Heliospheric Observatory spacecraft, and is comparable to the masses of many other three-dimensionally reconstructed solar wind features at 1 AU observed in SMEI 3D reconstructions.

Jackson, B. V.; Buffington, A.; Hick, P. P.; Clover, J. M.; Bisi, M. M. [Center for Astrophysics and Space Sciences, University of California at San Diego, 9500 Gilman Drive, 0424, La Jolla, CA 92093-0424 (United States); Webb, D. F. [Institute for Space Research, Boston College, Chestnut Hill, MA, 02467 (United States)

2010-12-01

199

Validation of a global 3D heliospheric model with observations for the May 12, 1997 CME event  

NASA Astrophysics Data System (ADS)

We simulate the May 12, 1997 space weather event from the Sun to the Earth. The initiation of the coronal mass ejection (CME) was done by superimposing a semi-circular, out-of-equilibrium magnetic flux rope onto a semi-empirical, steady-state solar corona model (SCM). The result at 1 AU was obtained by coupling the SCM with an inner heliosphere model (IHM). Our results demonstrate that the CME parameters can be obtained from magnetogram data and white-light observations and that the results at 1 AU can be simulated faster than the real time, even with the use of a relatively moderate computation resources. This particular event, however, is found to be very difficult to model, despite the fact that it is temporarily isolated in time from other CME events and it occurred during a solar minimum period. We found that the active region flux rope should be resolved with higher resolution in order to maintain its integrity while propagating into space. This way we can obtain a better agreement with measurements at 1 AU.

Cohen, O.; Sokolov, I. V.; Roussev, I. I.; Lugaz, N.; Manchester, W. B.; Gombosi, T. I.; Arge, C. N.

2008-02-01

200

Direction and orientation of CME/ICME events observed by STEREO  

NASA Astrophysics Data System (ADS)

The two NASA STEREO spacecraft are now approaching a quadrature configuration with respect to the Earth. In conjunction with the rising solar activity this represents a great opportunity to study coronal mass ejections (CMEs) during their journey from the Sun to 1 AU. We are in particular concerned with those events which were observed by the STEREO/SECCHI imaging instrument in the inner heliosphere and which were also detected in situ at 1 AU with STEREO (IMPACT/PLASTIC) or WIND (SWE/MFI). This allows for example to check (1) if the direction of propagation given by various direction-finding techniques is indeed correlated with the signatures which are later observed in situ and (2) if the orientation of the magnetic flux rope inside the ICME, which we model using the Grad-Shafranov technique, is reflected in properties of the CME. Also, the classic three-part structure of CMEs can be related to the in situ data. The results are discussed regarding the possibility to forecast ICME properties from observations closer to the Sun.

Moestl, Christian; Rollett, Tanja; Temmer, Manuela; Farrugia, Charles; Veronig, Astrid; Galvin, Antoinette; Biernat, Helfried K.

201

The role of CME dynamics in production of -10 MEV protons  

NASA Astrophysics Data System (ADS)

During January 1997 - June 1998, the Large Angle Spectroscopic Coronagraph (LASCO) aboard the Solar and Heliospheric Observatory spacecraft (SOHO) registered 670 coronal mass ejections (CMEs). We compare two groups of the 300-800 km s-1 CMEs: (i) (very) gradually accelerating CMEs with acceleration below 10 m s-2 , and (ii) impulsively accelerating CMEs with acceleration a > 20 m s-2 near the Sun, continuing then with the constant speed across the LASCO field of view. An association of those CMEs with solar energetic particle (SEP) events is studied using the data of the energetic particle experiment ERNE also aboard SOHO. There were no SEP events registered in association with the first group CMEs, whereas about 8% of the second group CMEs produced an enhancement in the ˜ 10 MeV proton flux at SOHO. This result along with a number of additional tests supports an idea that production of SEPs by the moderate speed CMEs depends not only on the final speed but also on the magnitude of acceleration that CME experiences during its liftoff. The SEP-producing CMEs are typified by impulsively accelerating CMEs accompanied by soft X-ray flares and coronal shocks.

Kocharov, L.; Torsti, J.; St. Cyr, O. C.

2001-08-01

202

Constraints on CME evolution from in situ observations of ionic charge states  

NASA Astrophysics Data System (ADS)

We present a novel analysis of the expansion properties of Coronal Mass Ejections (CMEs) in the inner corona. This methodology uses measurements of ionic charge states of C, O, Si, and Fe from the Advanced Composition Explorer (ACE) and interprets them in the context of a quantitative ionization model. All observed charge state distributions exhibit signatures of substantial heating, yet to varying degrees, reflecting peculiar properties of the frozen-in ions despite a common expansion profile. For example, the vast majority of ICMEs exhibit bi-modal Fe charge state distributions. Using a plasma heating and expansion model, in-situ charge states are translated into constraints on the heating and expansion profiles of the CME plasma. We find that CMEs are first heated up to ~3 MK near the Sun and with a maximum electron density between ~5e9 and 8.5e9 cm^-3 then followed by rapid expansion and cooling, These CMEs exhibit frozen-in charge states qualitatively and quantitatively consistent with our observations.

Gruesbeck, J. R.; Lepri, S. T.; Zurbuchen, T.; Antiochos, S. K.

2010-12-01

203

Are Decaying Magnetic Fields Above Active Regions Related to CME Onset?  

NASA Astrophysics Data System (ADS)

Coronal mass ejections (CMEs) are powered by magnetic energy stored in non-potential (current-carrying) coronal magnetic fields; the pre-CME field is thought to exhibit a balance between outward magnetic pressure of the proto-ejecta and inward magnetic tension from overlying fields that confine the proto-ejecta. In global potential (current-free) models of coronal magnetic fields --- potential field source-surface (PFSS) models --- above flare sites where CMEs originated, it has been noted that model field strengths are larger above sites where eruptions fail, suggesting potential field models might be useful to quantify magnetic confinement. One straightforward implication of this idea is that a decrease in model field strength overlying a possible eruption site should correspond to diminished confinement, implying an eruption is more likely. We have searched for such an effect by post facto investigation of the time evolution of model field strengths above a sample of 10 eruption sites. To check if the strengths of overlying fields were relevant only in relatively slow CMEs, we included both slow and fast CMEs in our sample.

Suzuki, J.; Welsch, B. T.; Li, Y.

2011-12-01

204

Analysis and study of the in situ observation of the June 1st 2008 CME by STEREO  

NASA Astrophysics Data System (ADS)

In this work we present a combined study of the counterpart of the coronal mass ejection (CME) of June 1st of 2008 in the interplanetary medium. This event has been largely studied because of its peculiar initiation and its possible forecasting consequences for space weather. We show an in situ analysis (on days June 6th-7th of 2008) of the CME in the interplanetary medium in order to shed some light on the propagation and evolution mechanisms of the interplanetary CME (ICME). The goals of this work are twofold: gathering the whole in situ data from PLASTIC and IMPACT onboard STEREO B in order to provide a complete characterization of the ICME, and to present a model where the thermal plasma pressure is included. The isolated ICME features show a clear forward shock which we identify as an oblique forward fast shock accelerating ions to a few-hundred keV during its passage. Following the shock, a flux rope is easily defined as a magnetic cloud (MC) by the magnetic field components and magnitude, and the low proton plasma-?. During the spacecraft passage through the MC, the energetic ion intensity shows a pronounced decrease, suggesting a closed magnetic topology, and the suprathermal electron population shows a density and temperature increase, demonstrating the importance of the electrons in the MC description. The in situ evidence suggests that there is no direct magnetic connection between the forward shock and the MC, and the characteristics of the reverse shock determined suggest that the shock pair is a consequence of the propagation of the ICME in the interplanetary medium. The energetic ions measured by the SEPT instrument suggest that their enhancement is not related to any solar event, but is solely due to the interplanetary shock consistent with the fact that no flares are observed on the Sun. The changes in the polarity of the interplanetary magnetic field in the vicinity of the ICME observed by electron PADs from SWEA are in accordance with the idea that the CME originated along a neutral line over the quiet Sun.The magnetic cloud model presented in this work provides the plasma pressure as a new factor to consider in the study of the expansion and evolution of CMEs in the interplanetary medium. This model could provide a new understanding of the Sun-Earth connection because of the important role that the plasma plays in the eruption of the CME in the solar corona and the reconnection process carried out with the Earth's magnetosphere.

Nieves-Chinchilla, T.; Gómez-Herrero, R.; Viñas, A. F.; Malandraki, O.; Dresing, N.; Hidalgo, M. A.; Opitz, A.; Sauvaud, J.-A.; Lavraud, B.; Davila, J. M.

2011-07-01

205

SCEC/CME CyberShake: Probabilistic Seismic Hazard Analysis Using 3D Seismic Waveform Modeling  

NASA Astrophysics Data System (ADS)

Researchers on the SCEC Community Modeling Environment (SCEC/CME) Project are calculating Probabilistic Seismic Hazard Curves for several sites in the Los Angeles area. The hazard curves calculated in this study use Intensity Measure Relationships (IMRs) based on 3D ground motion simulations rather than on attenuation relationships. State-of-the-art Probabilistic Seismic Hazard Analysis (PSHA) is currently conducted using IMRs that use empirically-based attenuation relationships. These attenuation relationships represent relatively simple analytical models based on the regression of observed data. However, it is widely believed that significant improvements in SHA will rely on the use of more physics-based, waveform modeling. In fact, a more physics-based approach to PSHA was endorsed in a recent assessment of earthquake science by National Research Council (2003). In order to introduce the use of 3D seismic waveform modeling into PSHA hazard curve calculations, the SCEC/CME CyberShake group is integrating state-of-the-art PSHA software tools (OpenSHA), SCEC-developed geophysical models (SCEC CVM3.0), validated anelastic wave modeling (AWM) software, and state-of-the-art computational technologies including high performance computing and grid-based scientific workflows in an effort to develop an OpenSHA-compatible 3D waveform-based IMR component. This will allow researchers to combine a new class of waveform-based IMRs with the large number of existing PSHA components, such as Earthquake Rupture Forecasts (ERF's), that are currently implemented in the OpenSHA system. To calculate a probabilistic hazard curve for a site of interest, we use the OpenSHA implementation of the NSHMP-2002 ERF and identify all ruptures within 200km of the site of interest. For each of these ruptures, we convert the NSHMP-2002 rupture definition into one, or more, Ruptures with Slip Time History (Rupture Variations) using newly developed Rupture Generator software. Strain Green Tensors are calculated for the site using well-validated AWM software together with the SCEC CVM3.0 3D velocity model. Then, using a reciprocity-based approach, we calculate synthetic seismograms for each Rupture Variation. The resulting suite of synthetics is processed to extract peak intensity measures of interest (such as spectral acceleration). The peak intensity measures are combined with the original rupture probabilities to produce probabilistic seismic hazard curves for the site. The CyberShake calculations are performed on high performance computing systems including multiple TeraGrid sites (currently SDSC and NCSA), and at USCs High Performance Computing and Communications (HPCC) center. The CyberShake job submission and data management uses a grid-based scientific workflow system based on the Virtual Data System (VDS) to manage the job scheduling and data management requirements of the work.

Callaghan, S.; Maechling, P. J.; Cui, Y.; Faerman, M.; Field, E.; Graves, R.; Gupta, N.; Gupta, V.; Jordan, T. H.; Kesselman, C.; Mehta, G.; Okaya, D.; Vahi, K.; Zhao, L.

2005-12-01

206

May 12 1997 CME Event: A Simplified Model of the Pre-Eruptive Magnetic Structure  

NASA Astrophysics Data System (ADS)

A simple model of the coronal magnetic field prior to the CME eruption on May 12 1997 is developed. First, this field is constructed by superimposing a large-scale background field and a localized bipolar field to model the active region (AR) in the potential approximation. The background field is determined from the observed photospheric normal field averaged over the longitude of the Sun. The AR field is modeled by a subphotospheric dipole whose parameters are optimized to fit the magnetic field obtained from an MDI magnetogram. Second, this potential configuration is quasi-statically sheared by photospheric vortex motions applied to two flux concentrations of the AR. Third, the resulting force-free field is then evolved by canceling the photospheric flux with the help of a flow converging to the neutral line of the AR. To understand the structure of the modeled configuration, we use a field line mapping technique generalized to spherical geometry. It is demonstrated that the initial configuration contains a hyperbolic flux tube (HFT) consisting of two intersecting quasi-separatrix layers. This HFT provides a partition of the closed magnetic flux between the AR and global solar magnetic field. Such a partition is approximate since the entire flux distribution is perfectly continuous. The vortex motions applied to the AR interlock the coronal field lines to form additionally two new HFTs pinched into thin current layers (CLs). These CLs carry the return current shielding the twisted field of the AR from a nearly potential background field. Reconnection in these CLs helps redistribute the flux in the configuration during the cancellation phase. At this phase, a magnetic flux rope is formed together with a bald patch separatrix surface wrapping around the rope. Other important implications of the identified structural features of the modeled configuration are also discussed.

Titov, Viacheslav; Mikic, Z.; Linker, J. A.; Lionello, R.

2007-05-01

207

COLON TARGETED DRUG DELIVERY SYSTEMS  

Microsoft Academic Search

Colon targeted drug delivery systems have the potential to deliver drugs for the treatment of a variety of colonic diseases and to deliver proteins and peptides to the colon for their systemic absorption. In recent years, various pharmaceutical approaches have been developed for targeting the drugs to the colon include, formation of prodrugs, coating of pH-sensitive polymers, use of colon

Ceyda Tuba

208

Elongated supramolecular assemblies in drug delivery.  

PubMed

This review presents different lipid-based elongated microstructures: tubules, cochleate cylinders and ribbons. Their composition, process of preparation and the mechanism behind their formation is discussed as well as their use as a drug delivery system. PMID:11992674

Zarif, Leila

2002-05-17

209

Coronal mass ejection (CME) activity of low mass M stars as an important factor for the habitability of terrestrial exoplanets. I. CME impact on expected magnetospheres of Earth-like exoplanets in close-in habitable zones.  

PubMed

Low mass M- and K-type stars are much more numerous in the solar neighborhood than solar-like G-type stars. Therefore, some of them may appear as interesting candidates for the target star lists of terrestrial exoplanet (i.e., planets with mass, radius, and internal parameters identical to Earth) search programs like Darwin (ESA) or the Terrestrial Planet Finder Coronagraph/Inferometer (NASA). The higher level of stellar activity of low mass M stars, as compared to solar-like G stars, as well as the closer orbital distances of their habitable zones (HZs), means that terrestrial-type exoplanets within HZs of these stars are more influenced by stellar activity than one would expect for a planet in an HZ of a solar-like star. Here we examine the influences of stellar coronal mass ejection (CME) activity on planetary environments and the role CMEs may play in the definition of habitability criterion for the terrestrial type exoplanets near M stars. We pay attention to the fact that exoplanets within HZs that are in close proximity to low mass M stars may become tidally locked, which, in turn, can result in relatively weak intrinsic planetary magnetic moments. Taking into account existing observational data and models that involve the Sun and related hypothetical parameters of extrasolar CMEs (density, velocity, size, and occurrence rate), we show that Earth-like exoplanets within close-in HZs should experience a continuous CME exposure over long periods of time. This fact, together with small magnetic moments of tidally locked exoplanets, may result in little or no magnetospheric protection of planetary atmospheres from a dense flow of CME plasma. Magnetospheric standoff distances of weakly magnetized Earth-like exoplanets at orbital distances

Khodachenko, Maxim L; Ribas, Ignasi; Lammer, Helmut; Griessmeier, Jean-Mathias; Leitner, Martin; Selsis, Franck; Eiroa, Carlos; Hanslmeier, Arnold; Biernat, Helfried K; Farrugia, Charles J; Rucker, Helmut O

2007-02-01

210

Coronal mass ejection (CME) activity of low mass M stars as an important factor for the habitability of terrestrial exoplanets. II. CME-induced ion pick up of Earth-like exoplanets in close-in habitable zones.  

PubMed

Atmospheric erosion of CO2-rich Earth-size exoplanets due to coronal mass ejection (CME)-induced ion pick up within close-in habitable zones of active M-type dwarf stars is investigated. Since M stars are active at the X-ray and extreme ultraviolet radiation (XUV) wave-lengths over long periods of time, we have applied a thermal balance model at various XUV flux input values for simulating the thermospheric heating by photodissociation and ionization processes due to exothermic chemical reactions and cooling by the CO2 infrared radiation in the 15 microm band. Our study shows that intense XUV radiation of active M stars results in atmospheric expansion and extended exospheres. Using thermospheric neutral and ion densities calculated for various XUV fluxes, we applied a numerical test particle model for simulation of atmospheric ion pick up loss from an extended exosphere arising from its interaction with expected minimum and maximum CME plasma flows. Our results indicate that the Earth-like exoplanets that have no, or weak, magnetic moments may lose tens to hundreds of bars of atmospheric pressure, or even their whole atmospheres due to the CME-induced O ion pick up at orbital distances CME plasma erosion. Therefore, we suggest that larger and more massive terrestrial-type exoplanets may better protect their atmospheres against CMEs, because the larger cores of such exoplanets would generate stronger magnetic moments and their higher gravitational acceleration would constrain the expansion of their thermosphere-exosphere regions and reduce atmospheric escape. PMID:17407407

Lammer, Helmut; Lichtenegger, Herbert I M; Kulikov, Yuri N; Griessmeier, Jean-Mathias; Terada, N; Erkaev, Nikolai V; Biernat, Helfried K; Khodachenko, Maxim L; Ribas, Ignasi; Penz, Thomas; Selsis, Franck

2007-02-01

211

Speed evolution of fast CME/shocks with SOHO/LASCO, WIND/WAVES, IPS and in-situ WIND data: analysis of kilometric type-II emissions  

NASA Astrophysics Data System (ADS)

Fast CME/shocks propagating in the interplanetary medium can generate kilometric Type II (km-TII) radio emissions at the local plasma frequency and/or its harmonic, so these radio emissions provide a means of remotely tracking CME/shocks. We apply a new analysis technique, using the frequency drift of km-TII spectrum obtained by the Thermal Noise Receiver (TNR) of the WIND/WAVES experiment, to infer, at some adequate intervals, the propagation speed of six CME/shocks. We combine these results with previously reported speeds from coronagraph white light and interplanetary scintillation observations, and in-situ measurements, to study the temporal speed evolution of the six events. The speed values obtained by the km-TII analysis are in a reasonable agreement with the speed measurements obtained by other techniques at different heliocentric distance ranges. The combination of all the speed measurements show a gradual deceleration of the CME/shocks as they propagate to 1 AU. This new technique can be useful in studying the evolution of fast CME/shocks when adequate intervals of km-TII emissions are available.

Gonzalez-Esparza, A.; Aguilar-Rodriguez, E.

2009-10-01

212

43 CFR Appendix II to Part 11 - Format for Data Inputs and Modifications to the NRDAM/CME  

Code of Federal Regulations, 2010 CFR

...contain vegetation (e.g., wetland, seagrass, or kelp) or invertebrate reef (e.g...contain vegetation (e.g., wetlands, seagrass, or kelp) or invertebrate reef (e.g...contains vegetation (e.g., wetlands, seagrass, or kelp) or invertebrate reef...

2010-10-01

213

43 CFR Appendix II to Part 11 - Format for Data Inputs and Modifications to the NRDAM/CME  

Code of Federal Regulations, 2010 CFR

...contain vegetation (e.g., wetland, seagrass, or kelp) or invertebrate reef (e.g...contain vegetation (e.g., wetlands, seagrass, or kelp) or invertebrate reef (e.g...contains vegetation (e.g., wetlands, seagrass, or kelp) or invertebrate reef...

2009-10-01

214

Transforming in-situ observations of CME-driven shock accelerated protons into the shock's reference frame.  

NASA Astrophysics Data System (ADS)

We examine the solar energetic particle event following solar activity from 14, 15 April 2001 which includes a "bump-on-the-tail" in the proton energy spectra at 0.99 AU from the Sun. We find this population was generated by a CME-driven shock which arrived at 0.99 AU around midnight 18 April. As such this population represents an excellent opportunity to study in isolation, the effects of proton acceleration by the shock. The peak energy of the bump-on-the-tail evolves to progressively lower energies as the shock approaches the observing spacecraft at the inner Lagrange point. Focusing on the evolution of this peak energy we demonstrate a technique which transforms these in-situ spectral observations into a frame of reference co-moving with the shock whilst making allowance for the effects of pitch angle scattering and focusing. The results of this transform suggest the bump-on-the-tail population was not driven by the 15 April activity but was generated or at least modulated by a CME-driven shock which left the Sun on 14 April. The existence of a bump-on-the-tail population is predicted by models in Rice et al. (2003) and Li et al. (2003) which we compare with observations and the results of our analysis in the context of both the 14 April and 15 April CMEs. We find an origin of the bump-on-the-tail at the 14 April CME-driven shock provides better agreement with these modelled predictions although some discrepancy exists as to the shock's ability to accelerate 100 MeV protons. Keywords. Solar physics, astrophysics and astronomy (Energetic particles; Flares and mass ejections) Space plasma physics (Transport processes)

Robinson, I. M.; Simnett, G. M.

2005-07-01

215

E-mail access to NetCME: implementation of server push paradigm.  

PubMed

We describe the implementation of a Continuing Medical Education project which utilizes e-mail delivery of HTML documents to facilitate participant access to case material. HTML e-mail is displayed directly within the e-mail reader of the Netscape browser. This system of proactive educational content delivery ensures simultaneous distribution to all participants. Although a more effective method of content distribution, the system preserves user confidentiality and maintains security. HTML e-mail is non-proprietary and could be integrated into existing Internet-based educational projects to facilitate user access. PMID:9357714

McEnery, K W; Grossman, J E

1997-01-01

216

Substorms and polar cap convection: the 10 January 2004 interplanetary CME case  

NASA Astrophysics Data System (ADS)

The expansion-contraction model of Dungey cell plasma convection has two different convection sources, i.e. reconnections at the magnetopause and in the magnetotail. The spatial-temporal structure of the nightside source is not yet well understood. In this study we shall identify temporal variations in the winter polar cap convection structure during substorm activity under steady interplanetary conditions. Substorm activity (electrojets and particle precipitations) is monitored by excellent ground-satellite DMSP F15 conjunctions in the dusk-premidnight sector. We take advantage of the wide latitudinal coverage of the IMAGE chain of ground magnetometers in Svalbard - Scandinavia - Russia for the purpose of monitoring magnetic deflections associated with polar cap convection and substorm electrojets. These are augmented by direct observations of polar cap convection derived from SuperDARN radars and cross-track ion drift observations during traversals of polar cap along the dusk-dawn meridian by spacecraft DMSP F13. The interval we study is characterized by moderate, stable forcing of the magnetosphere-ionosphere system (EKL = 4.0-4.5 mV m-1; cross polar cap potential (CPCP), ? (Boyle) = 115 kV) during Earth passage of an interplanetary CME (ICME), choosing an 4-h interval where the magnetic field pointed continuously south-west (Bz < 0; By < 0). The combination of continuous monitoring of ground magnetic deflections and the F13 cross-track ion drift observations in the polar cap allows us to infer the temporal CPCP structure on time scales less than the ~10 min duration of F13 polar cap transits. We arrived at the following estimates of the dayside and nightside contributions to the CPCP (CPCP = CPCP/day + CPCP/night) under two intervals of substorm activity: CPCP/day ~110 kV; CPCP/night ~50 kV (45% CPCP increase during substorms). The temporal CPCP structure during one of the substorm cases resulted in a dawn-dusk convection asymmetry measured by DMSP F13 which is opposite to that expected from the prevailing negative By polarity of the ICME magnetic field, a clear indication of a nightside source.

Andalsvik, Y.; Sandholt, P. E.; Farrugia, C. J.

2012-01-01

217

Comparison of chorus wave power during CIR versus CME-driven geomagnetic storms  

NASA Astrophysics Data System (ADS)

One of the major outstanding scientific problems in the field of heliophysics is understanding and quantifying the dominant source and loss processes that contribute to the variability of relativistic electron populations in the Earth's outer radiation belt. It is known that the dynamics of the outer belt is highly dependent on the driving solar wind conditions during and in the aftermath of geomagnetic storms. For example, geomagnetic storms driven by corotating interaction regions (CIRs) and the following high speed stream (HSS) are particularly efficient at coupling energy into the magnetosphere. Despite the fact that CIR/HSS-driven storms have on average a weaker Dst signature than storms driven by coronal mass ejections (CMEs), these storms typically result in significant outer belt flux enhancements. One process that is believed to play a major role in the evolution of the outer belt is cyclotron-resonant wave particle interactions involving whistler-mode chorus emissions. Chorus interactions can result in the precipitative loss of electrons over a wide range of energy as well as the acceleration of seed electrons (10's to 100's of keV) up to energies of an MeV or greater. Progress in quantifying the role of chorus in radiation belt dynamics requires knowledge of how the chorus wave power varies with time and space as a function of solar wind and magnetospheric conditions. While in situ measurements of chorus are relatively sparse during solar cycle 23, a large database of ground-based ELF/VLF observations from Antarctica exist for this period. Here we examine the variation of chorus activity observed on the ground during a set of geomagnetic storms from 2000 to 2010. We analyze data from Palmer Station, Antarctica (?=-50o) and South Pole Station, Antarctica (?=-74o) thus covering waves generated in the inner magnetosphere as well as in the dayside outer magnetosphere. We explore differences in the intensity, duration and spectral extent of chorus between CIR/HSS-driven storms and CME-driven storms, and we put the results in the context of the global magnetospheric response such as differences in substorm activity and plasmasheet density and temperature.

Spasojevic, M.; Golden, D. I.

2011-12-01

218

A Parametric Study of Erupting Flux Rope Rotation. Modeling the "Cartwheel CME" on 9 April 2008  

NASA Astrophysics Data System (ADS)

The rotation of erupting filaments in the solar corona is addressed through a parametric simulation study of unstable, rotating flux ropes in bipolar force-free initial equilibrium. The Lorentz force due to the external shear-field component and the relaxation of tension in the twisted field are the major contributors to the rotation in this model, while reconnection with the ambient field is of minor importance, due to the field's simple structure. In the low-beta corona, the rotation is not guided by the changing orientation of the vertical field component's polarity inversion line with height. The model yields strong initial rotations which saturate in the corona and differ qualitatively from the profile of rotation vs. height obtained in a recent simulation of an eruption without preexisting flux rope. Both major mechanisms writhe the flux rope axis, converting part of the initial twist helicity, and produce rotation profiles which, to a large part, are very similar within a range of shear-twist combinations. A difference lies in the tendency of twist-driven rotation to saturate at lower heights than shear-driven rotation. For parameters characteristic of the source regions of erupting filaments and coronal mass ejections, the shear field is found to be the dominant origin of rotations in the corona and to be required if the rotation reaches angles of order 90 degrees and higher; it dominates even if the twist exceeds the threshold of the helical kink instability. The contributions by shear and twist to the total rotation can be disentangled in the analysis of observations if the rotation and rise profiles are simultaneously compared with model calculations. The resulting twist estimate allows one to judge whether the helical kink instability occurred. This is demonstrated for the erupting prominence in the "Cartwheel CME" on 9 April 2008, which has shown a rotation of ? 115? up to a height of 1.5 R ? above the photosphere. Out of a range of initial equilibria which include strongly kink-unstable (twist ?=5 ?), weakly kink-unstable (?=3.5 ?), and kink-stable (?=2.5 ?) configurations, only the evolution of the weakly kink-unstable flux rope matches the observations in their entirety.

Kliem, B.; Török, T.; Thompson, W. T.

2012-11-01

219

First magnetic seismology of the CME reconnection outflow layer in the low corona with 2.5-D MHD simulations of the Kelvin-Helmholtz instability  

NASA Astrophysics Data System (ADS)

For conditions observed in the low corona, we perform 2.5-D magnetohydrodynamic (MHD) simulations of the Kelvin-Helmholtz instability (KHI) at the surface of a coronal mass ejection (CME). We match the observed time development of the KHI with simulated growth from 110 MHD experiments representing a parametric range of realistic magnetic field strengths and orientations and two key values of the velocity shear, ?V, inferred from observations. The results are field strengths Be? 8-9 G and Bs? 10-11 G in the CME reconnection outflow layer and the surrounding sheath, respectively, for ?V?770kms-1; for nearly perpendicular orientation (1° tilt) of Bs with respect to the flow plane, Be can be tilted between 3 and 10°; tilting Bs up to 15° would slow the growth of the KHI by too much. Our simulations also reveal hidden dynamics and structure of the CME ejecta layer such as plasma mixing via reconnection in the vortices.

Nykyri, Katariina; Foullon, Claire

2013-08-01

220

The First Ground Level Enhancement Event of Solar Cycle 24: Direct Observation of Shock Formation and Particle Release Heights  

NASA Astrophysics Data System (ADS)

We report on the 2012 May 17 ground level enhancement (GLE) event, which is the first of its kind in solar cycle 24. This is the first GLE event to be fully observed close to the surface by the Solar Terrestrial Relations Observatory (STEREO) mission. We determine the coronal mass ejection (CME) height at the start of the associated metric type II radio burst (i.e., shock formation height) as 1.38 Rs (from the Sun center). The CME height at the time of GLE particle release was directly measured from a STEREO image as 2.32 Rs, which agrees well with the estimation from CME kinematics. These heights are consistent with those obtained for cycle-23 GLEs using back-extrapolation. By contrasting the 2012 May 17 GLE with six other non-GLE eruptions from well-connected regions with similar or larger flare sizes and CME speeds, we find that the latitudinal distance from the ecliptic is rather large for the non-GLE events due to a combination of non-radial CME motion and unfavorable solar B0 angle, making the connectivity to Earth poorer. We also find that the coronal environment may play a role in deciding the shock strength.

Gopalswamy, N.; Xie, H.; Akiyama, S.; Yashiro, S.; Usoskin, I. G.; Davila, J. M.

2013-03-01

221

Reconnection Outflows and Current Sheet Observed with Hinode/XRT in the April 9 2008 "Cartwheel CME" Flare  

NASA Astrophysics Data System (ADS)

Supra-arcade downflows (SADs) have been observed with Yohkoh/SXT (soft X-rays (SXR)), TRACE (extreme ultra-violet (EUV)), SoHO/LASCO (white light), SoHO/SUMER (EUV spectra), and Hinode/XRT (SXR). Characteristics such as low emissivity and trajectories which slow as they reach the top of the arcade are consistent with post-reconnection magnetic flux tubes. The magnetic flux within the tubes provides pressure against filling with plasma. As with the standard model of reconnection, the tubes then retract from a reconnection site high in the corona until they reach a more potential magnetic configuration. Viewed from a perpendicular angle, SADs should appear as shrinking loops rather than downflowing voids. We will present observations of supra-arcade downflowing loops (SADLs) following a CME on April 9, 2008 with XRT and show that their speeds and decelerations are consistent with those determined for SADs. We will also present evidence for a possible current sheet observed during this flare that extends between the CME and the flare arcade. Additionally, we will show a correlation between reconnection outflows observed with XRT and outgoing flows observed with LASCO.

Savage, Sabrina; McKenzie, D. E.; Reeves, K. K.; Forbes, T. G.; Longcope, D. W.

2010-05-01

222

Effectiveness of CME on "Pediatric Emergencies and Management" Among the Health Personnels in Community Health Centre, Karikalampakkam, Puducherry.  

PubMed

OBJECTIVES: To assess the level of knowledge among health personnels on pediatric emergencies and their management and to evaluate the effectiveness of CME programme on the same. METHODS: This study was conducted at Karikalampakkam village of Puducherry. Karikalampakkam is a Community Health Center with seven subcenters under it. The research design was one of the Quasi Experimental Design pre and post test with one group. All the health personnels like ANM, PHN, Health educators were considered as subjects for the study. The sample size was 40 and selected by purposive sampling technique. Pretest was conducted before the CME programme with the structured interview schedule. Post test was conducted after completion of the programme with the help of same tool. RESULTS: The pretest mean knowledge score among the health personnels was 3.15?±?0.89 with the mean percentage 7.8 % whereas the posttest mean knowledge score was 4.47?±?1.58 with mean percentage 11.17 %. The Z value was -2.555 and the p value was 0.011 (p?

Vasudevaiah, V; Dash, Manjubala

2013-05-30

223

2.5D MHD Simulations of the Kelvin-Helmholtz Instability at CME-Boundaries in the Solar Corona  

NASA Astrophysics Data System (ADS)

We discuss the observation of a coronal mass ejection (CME) by the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory from 2011 February 24. This CME with an embedded filament shows periodic vortex-like structures at the northern side of the filament boundary with a wavelength of approximately 14.4 Mm and a propagation speed of about 310 ± 20 km/s. The morphological analysis hints at structures produced by the Kelvin-Helmholtz (KH) instability on the boundary of the filament. We conduct 2.5D numerical simulations of the KH instability, whose results yield qualitative as well as quantitative agreements with the observations. Furthermore, we study the absence of KH vortex-like structures on the southern side of the filament boundary and find that a magnetic field component parallel to the boundary with a strength of about 20% of the total magnetic field has stabilizing effects resulting in an asymmetric development of the instability. This work receives funding from the Austrian Science Fund (FWF): P21051-N16, V195-N16 and P24092-N16.

Möstl, Ute; Temmer, Manuela; Veronig, Astrid

2013-04-01

224

RECONNECTION OUTFLOWS AND CURRENT SHEET OBSERVED WITH HINODE/XRT IN THE 2008 APRIL 9 'CARTWHEEL CME' FLARE  

SciTech Connect

Supra-arcade downflows (SADs) have been observed with Yohkoh/SXT (soft X-rays (SXR)), TRACE (extreme ultraviolet (EUV)), SOHO/LASCO (white light), SOHO/SUMER (EUV spectra), and Hinode/XRT (SXR). Characteristics such as low emissivity and trajectories, which slow as they reach the top of the arcade, are consistent with post-reconnection magnetic flux tubes retracting from a reconnection site high in the corona until they reach a lower-energy magnetic configuration. Viewed from a perpendicular angle, SADs should appear as shrinking loops rather than downflowing voids. We present X-ray Telescope (XRT) observations of supra-arcade downflowing loops (SADLs) following a coronal mass ejection (CME) on 2008 April 9 and show that their speeds and decelerations are consistent with those determined for SADs. We also present evidence for a possible current sheet observed during this flare that extends between the flare arcade and the CME. Additionally, we show a correlation between reconnection outflows observed with XRT and outgoing flows observed with LASCO.

Savage, Sabrina L.; McKenzie, David E.; Longcope, Dana W. [Department of Physics, Montana State University, P.O. Box 173840, Bozeman, MT 59717-3840 (United States); Reeves, Katharine K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS 58, Cambridge, MA 02138 (United States); Forbes, Terry G. [Institute for the Study of Earth, Oceans, and Space (EOS), University of New Hampshire, 39 College Road, Durham, NH 03824 (United States)

2010-10-10

225

Magnetoelastic coupling in [Ru2(O2CMe)4]3[Cr(CN)6] molecule-based magnet  

NASA Astrophysics Data System (ADS)

Infrared and Raman vibrational spectroscopies were employed to explore the lattice dynamics of [Ru2(O2CMe)4]3[Cr(CN)6] through the field- and temperature-driven magnetic transitions. The high field work reveals systematic changes in the C?N stretching mode and Cr-containing phonons as the system is driven away from the antiferromagnetic state. The magnetic intersublattice coalescence transition at Bc?0.08 T, on the contrary, is purely magnetic and takes place with no lattice involvement. The variable temperature spectroscopy affirms overall [Cr(CN)6]3- flexibility along with stronger intermolecular interactions at low temperature. Based on a displacement pattern analysis, we discuss the local lattice distortions in terms of an adaptable chromium environment. These findings provide deeper understanding of spin-lattice coupling in [Ru2(O2CMe)4]3[Cr(CN)6] and may be useful in the development of technologically important molecule-based magnets.

Brinzari, T. V.; Chen, P.; Tung, L.-C.; Kim, Y.; Smirnov, D.; Singleton, J.; Miller, Joel. S.; Musfeldt, J. L.

2012-12-01

226

Paliperidone Loaded Self Emulsifying Drug Delivery Systems (SEDDS) for Improved Oral Delivery  

Microsoft Academic Search

The present research is aimed to improve the oral delivery of paliperidone by loading into self emulsifying drug delivery systems (SEDDS). Oleic acid, tween 80 and capmul MCM L8 were selected as oil, surfactant and co-surfactant respectively and phase diagram was constructed and the region was identified for the formation of SEDDS. The stable formulations were analyzed for globule size,

Swetha Kanuganti; Raju Jukanti; Prabhakar R. Veerareddy; Suresh Bandari

2011-01-01

227

Cytosolic Delivery of Granzyme B by Bacterial Toxins: Evidence that Endosomal Disruption, in Addition to Transmembrane Pore Formation, Is an Important Function of Perforin  

PubMed Central

Granule-mediated cell killing by cytotoxic lymphocytes requires the combined actions of a membranolytic protein, perforin, and granule-associated granzymes, but the mechanism by which they jointly kill cells is poorly understood. We have tested a series of membrane-disruptive agents including bacterial pore-forming toxins and hemolytic complement for their ability to replace perforin in facilitating granzyme B-mediated cell death. As with perforin, low concentrations of streptolysin O and pneumolysin (causing <10% 51Cr release) permitted granzyme B-dependent apoptosis of Jurkat and Yac-1 cells, but staphylococcal alpha-toxin and complement were ineffective, regardless of concentration. The ensuing nuclear apoptotic damage was caspase dependent and included cleavage of poly(ADP-ribose) polymerase, suggesting a mode of action similar to that of perforin. The plasma membrane lesions formed at low dose by perforin, pneumolysin, and streptolysin did not permit diffusion of fluorescein-labeled proteins as small as 8 kDa into the cell, indicating that large membrane defects are not necessary for granzymes (32 to 65 kDa) to enter the cytosol and induce apoptosis. The endosomolytic toxin, listeriolysin O, also effected granzyme B-mediated cell death at concentrations which produced no appreciable cell membrane damage. Cells pretreated with inhibitors of endosomal trafficking such as brefeldin A took up granzyme B normally but demonstrated seriously impaired nuclear targeting of granzyme B when perforin was also added, indicating that an important role of perforin is to disrupt vesicular protein trafficking. Surprisingly, cells exposed to granzyme B with perforin concentrations that produced nearly maximal 51Cr release (1,600 U/ml) also underwent apoptosis despite excluding a 8-kDa fluorescein-labeled protein marker. Only at concentrations of >4,000 U/ml were perforin pores demonstrably large enough to account for transmembrane diffusion of granzyme B. We conclude that pore formation may allow granzyme B direct cytosolic access only when perforin is delivered at very high concentrations, while perforin’s ability to disrupt endosomal trafficking may be crucial when it is present at lower concentrations or in killing cells that efficiently repair perforin pores.

Browne, Kylie A.; Blink, Elizabeth; Sutton, Vivien R.; Froelich, Christopher J.; Jans, David A.; Trapani, Joseph A.

1999-01-01

228

An operational software tool for the analysis of coronagraph images: Determining CME parameters for input into the WSA-Enlil heliospheric model  

NASA Astrophysics Data System (ADS)

Coronal mass ejections (CMEs)—massive explosions of dense plasma that originate in the lower solar atmosphere and propagate outward into the solar wind—are the leading cause of significant space weather effects within Earth's environment. Computational models of the heliosphere such as WSA-Enlil offer the possibility of predicting whether a given CME will become geo-effective and, if so, the likely time of arrival at Earth. To be meaningful, such a forecast model is dependent upon accurately characterizing key parameters for the CME, notably its speed and direction of propagation, and its angular width. Studies by Zhao et al. (2002) and Xie et al. (2004) suggest that these key CME parameters can be deduced from geometric analysis of the elliptical "halo" forms observed in coronagraph images on spacecraft such as the Solar and Heliospheric Observatory (SOHO) and which result from a CME whose propagation is roughly toward or away from the observer. Both studies assume that the CME presents a circular cross-section and maintains a constant angular width during its radial expansion, the so called "cone model." Development work at the NOAA Space Weather Prediction Center (SWPC) has been concerned with building and testing software tools to allow forecasters to determine these CME parameters routinely within an operational context, a key aspect of transitioning the WSA-Enlil heliospheric model into operations at the National Weather Service. We find "single viewpoint" cone analysis, while a useful start, to be highly problematic in many real-world situations. In particular, it is extremely difficult to establish objectively the correct ellipse that should be applied to a given halo form and that small changes in the exact ellipse chosen can lead to large differences in the deduced CME parameters. The inaccuracies in the technique are particularly evident for analysis of the "nearly circular" elliptical forms which result from CMEs that are propagating directly toward the observer and are therefore the most likely to be geo-effective. In working to resolve this issue we have developed a new three-dimensional (3-D) graphics-based analysis system which seeks to reduce inaccuracies by analyzing a CME using coronagraph images taken concurrently by SOHO and also by the two Solar TErrestrial RElations Observatory (STEREO) spacecraft, which provide additional viewing locations well away from the Sun-Earth line. The resulting "three view" technique has led to the development of the CME Analysis Tool (CAT), an operational software system in routine use at the SWPC as the primary means to determine CME parameters for input into the WSA-Enlil model. Results from the operational WSA-Enlil system are presented: utilizing CAT to provide CME input parameters, we show that, during the first year of operations at SWPC, the WSA-Enlil model has forecasted the arrival of CMEs at Earth with an average error 7.5 h.

Millward, G.; Biesecker, D.; Pizzo, V.; Koning, C. A.

2013-02-01

229

Transdermal drug delivery  

Microsoft Academic Search

Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, noncavitational ultrasound and iontophoresis have also resulted

Mark R Prausnitz; Robert Langer

2008-01-01

230

Nanoparticles as 'smart' pharmaceutical delivery.  

PubMed

Pharmaceuticals in conjunction with nanoparticle delivery systems are growing towards new heights. The aim of this review is to gain a thorough understanding of different types and characteristics of nanoparticle based delivery systems, important properties of delivery systems, pharmaceutical ingredient loading and release in the nanoparticle delivery systems. In this review, we have also highlighted about the promising pharmaceutical deliveries like brain targeted delivery, ocular delivery, oral delivery, dermal and transdermal delivery, cancer chemotherapy, vaccine delivery, nucleic acids delivery and delivery system coupling to implants. A snapshot of the nanoparticle mediated drug deliveries which are commercially available and ongoing clinical trials have been provided. PMID:23747865

Chakraborty, Chiranjib; Pal, Soumen; Doss, George Priya C; Wen, Zhi-Hong; Lin, Chan-Shing

2013-06-01

231

Calculation of CME kinematics and propagation directions by connecting STEREO HI-images with in situ data  

NASA Astrophysics Data System (ADS)

On a sample of selected events we determined the propagation directions and the kinematics of several coronal mass ejections by using data provided by the Heliospheric Imagers (HI) and the PLASTIC and IMPACT instruments onboard the two STEREO satellites and the Wind spacecraft near Earth. We tracked for each CME the leading edge and core within time-elongation plots (Jplots) and converted the measured elongation angle into distance by using different methods (Point-P, Fixed-Phi and their harmonic mean). Furthermore, we used the Sheeley-method to fit our measurements and calculate the propagation angles and arrival times at the other spacecraft assuming that the CMEs propagate with constant velocity. Finally we discuss our results by comparing the kinematics derived from the different techniques.

Rollett, Tanja; Moestl, Christian; Temmer, Manuela; Veronig, Astrid; Biernat, Helfried K.

232

[Usability study of an e-learning system for CME in occupational medicine: preparatory analysis and remedial actions].  

PubMed

This paper describes the activities carried out in order to make an e-learning system for CME be a good tool in terms of usability. The following steps are described:--the needs analysis of the potential users;--the prototype of the e-learning system that has been set up;--the usability evaluation of the prototype by a sample often users before and after the implementation of the identified remedial actions. The obtained results support the hypothesis of an effective usage of the system in the near future. The follow-up of real users' usage, through the tracing facilities of the e-learning platform, will confirm or reject our hypothesis. PMID:19344087

Mazzoleni, M C; Rognoni, C; Finozzi, E; Giorgi, I; Raho, C; Nervi, D; Pugliese, F; Pagani, M; Imbriani, M

233

MICROWAVE QUASI-PERIODIC PULSATIONS IN MULTI-TIMESCALES ASSOCIATED WITH A SOLAR FLARE/CME EVENT  

SciTech Connect

Microwave observations of quasi-periodic pulsations (QPPs) in multi-timescales at the Solar Broadband Radio Spectrometer in Huairou (SBRS/Huairou) on 2006 December 13 are confirmed to be associated with an X3.4 flare/coronal mass ejection (CME) event. It is most remarkable that the timescales of QPPs are distributed in a broad range from hectoseconds (very long period pulsation, VLP, P>100 s), decaseconds (long period pulsation, LPP, 10 < P < 100 s), a few seconds (short period pulsation, SPP, 1 < P < 10 s), deciseconds (slow very short period pulsation, slow-VSP, 0.1 < P < 1.0 s), to centiseconds (fast very short period pulsation, fast-VSP, P < 0.1 s), and form a broad hierarchy. The statistical distribution of QPPs in logarithmic period-duration space indicates that all the QPPs can be classified into two groups: group I includes VLP, LPP, SPP, and some slow-VSPs distributed approximately around a line; group II includes fast-VSP and most of the slow-VSPs dispersively distributed away from the above line. This feature implies that the generation mechanism of group I is different from group II. Group I is possibly related to some MHD oscillations in magnetized plasma loops in the active region; e.g., VLPs may be generated by standing slow sausage mode coupling, resonating with the underlying photospheric 5 minute oscillation, with the modulation amplified and forming the main framework of the whole flare/CME process; LPPs, SPPs, and some slow-VSPs are most likely to be caused by standing fast modes or LRC-circuit resonance in current-carrying plasma loops. Group II is possibly generated by modulations of resistive tearing-mode oscillations in electric current-carrying flaring loops.

Tan Baolin; Zhang Yin; Tan Chengming; Liu Yuying, E-mail: bltan@nao.cas.c [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences (China)

2010-11-01

234

Determination of the cobpoint evolution using 3D MHD simulations for the propagation of CME-driven shocks  

NASA Astrophysics Data System (ADS)

Particle flux profile of large solar energetic particle (SEP) events depends on several factors, such as the strength and geometry of the associated CME-driven shock, the relative position of the observer with respect to the leading direction of the travelling shock, the conditions for the particle acceleration, the injection and the transport throughout the interplanetary space, and the particle energy. In this study we focus on two of these factors: the influence of the shock and the relative position of the observer. We performed a 3D simulation of the propagation of a coronal/interplanetary CME-driven shock from the Sun up to 1 AU in the framework of ideal MHD using the Versatile Advection Code (Toth et al., 1996). Three spacecrafts are located at 1 AU at different longitudes with respect to the nose of the shock. We study the evolution of the plasma conditions in the shock front region magnetically connected to each spacecraft, that is, the region of the shock front scanned by the cobpoint (Heras et al., 1995) as the shock propagates away from the Sun. The conclusions about the influence of these changing conditions on the injection rate of shock-accelerated particles are presented. References Toth, G. A General Code for Modelling MHD flows on Parallel Computers: Versatile Advection Code, Astrophys. Lett. and Comm., 34, 245, 1996. Heras, A.M., Sanahuja, B., Lario, D., et al. Three low-energy particle events: modeling the influence of the parent interplanetary shock. Astrophys. J. 445, 497-508, 1995.

Rodriguez-Gasen, Rosa; Aran, Angels; Sanahuja, Blai; Jacobs, Carla; Poedts, Stefaan

235

Reactions of the cationic diruthenium carbonyl complex [Ru 2(?-dppm) 2(CO) 4(?,? 2-O 2CMe)] + with bidentate ligands; intramolecularly assisted stereospecific synthesis via the second-sphere face-to-face ?–? stacking interactions  

Microsoft Academic Search

The reactions of the diruthenium carbonyl complexes [Ru2(?-dppm)2(CO)4(?,?2-O2CMe)]X (X=BF4? (1a) or PF6? (1b)) with neutral or anionic bidentate ligands (L,L) afford a series of the diruthenium bridging carbonyl complexes [Ru2(?-dppm)2(?-CO)2(?2-(L,L))2]Xn ((L,L)=acetate (O2CMe), 2,2?-bipyridine (bpy), acetylacetonate (acac), 8-quinolinolate (quin); n=0, 1, 2). Apparently with coordination of the bidentate ligands, the bound acetate ligand of [Ru2(?-dppm)2(CO)4(?,?2-O2CMe)]+ either migrates within the same complex

Kom-Bei Shiu; Shih-Wei Jean; Yu Wang; Gene-Hsiang Lee

2002-01-01

236

Dental Delivery Systems Terminology.  

National Technical Information Service (NTIS)

In order to facilitate communications among those involved in the study of dental services delivery the Delivery Systems Branch, Division of Dentistry prepared this glossary of the terms they use. They define dental health services as nonclinical services...

1976-01-01

237

Reactions of (Me 2C)(Me 2Si)[(? 5-C 5H 3)Mo(CO) 3] 2 with nitrile and subsequent cleavage of the C N bond by cooperation of molybdenum and ruthenium  

Microsoft Academic Search

Reaction of the doubly bridged dinuclear molybdenum complex (Me2C)(Me2Si)[(?5-C5H3)Mo(CO)3]2 (1) with benzonitrile in refluxing xylene afforded complexes (Me2C)(Me2Si)[(?5-C5H3)2Mo2(CO)4(?-?2-?2(?)-NCPh)] (2) (50%) and (Me2C)(Me2Si)[(?5-C5H3)2Mo2(CO)4(?-?1-?2-NCPh)] (3) (6%) with different coordination of nitrile. The corresponding ?-?2-?2 acetonitrile and propionitrile complexes 4 and 5 could be obtained from the reactions of (Me2C)(Me2Si)(C5H4)2 with (RCN)3Mo(CO)3 (R=Me, Et) in refluxing xylene. Reactions of 1 with isonitriles generated

Bin Li; Shansheng Xu; Haibin Song; Baiquan Wang

2008-01-01

238

Colloidal drug delivery systems in vaccine delivery.  

PubMed

Vaccines play a vital role in the field of community medicine to combat against several diseases of human existence. Vaccines primarily trigger the acquired immune system to develop long-lasting immunity against pathogens. Conventional approaches for vaccine delivery lacks potential to target a particular antigen to develop acquired immunity by specific antibodies. Recent advancements in vaccine delivery showed that inclusion of adjuvants in vaccine formulations or delivery of them in a carrier helps in achieving desired targeting ability, reducing the immunogenicity and significant augmentation in the immune response. Colloidal carriers (liposomes, niosomes, microspheres, proteosomes, virosomes and virus like particles (VLPs), antigen cochleates, dendrimers and carbon nanotubes) have been widely explored for vaccine delivery. Further, surface engineering of these carriers with ligands, functional moieties and monoclonal antibodies tend to enhance the immune recognition potential of vaccines by differentiation of antigen specific memory T-cells. The current review, therefore, provides an updated account on the recent advancements in various colloidal delivery systems in vaccine delivery, outlining the mechanism of immune response initiated by them along with potential applications and marketed instances in an explicit manner. PMID:23072326

Beg, Sarwar; Samad, Abdus; Nazish, Iram; Sultana, Ruksar; Rahman, Mahfoozur; Ahmad, Md Zaki; Akbar, Md

2013-01-01

239

Paliperidone-Loaded Self-Emulsifying Drug Delivery Systems (SEDDS) for Improved Oral Delivery  

Microsoft Academic Search

The present research is aimed to improve the oral delivery of paliperidone by loading into self-emulsifying drug delivery systems (SEDDS). Oleic acid, Tween 80, and capmul MCM L8 were selected as oil, surfactant, and co-surfactant, respectively and phase diagram was constructed and the region was identified for the formation of SEDDS. The stable formulations were analyzed for globule size, robustness

Swetha Kanuganti; Raju Jukanti; Prabhakar R. Veerareddy; Suresh Bandari

2012-01-01

240

Capturing the Three-Dimensional Motion of the 16 June 2010 CME in the STEREO-SECCHI Observations using Scene Flow  

NASA Astrophysics Data System (ADS)

The motion of coronal mass ejections (CMEs) in the heliosphere is governed by the complex interactions of the magnetic field and gas pressure both internal and external to the CME. The two-viewpoint observations of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite abroad the Solar TErrestrial RElations Observatory (STEREO) mission is a unique resource for studying these forces throughout the heliosphere. To access the fullest potential of these data, we first need to apply advanced image analysis tools to deal with the three-dimensional data. Here, we present the application of the computer vision technique of scene flow on the CME observed by SECCHI on 10 June 2010. Scene flow methods estimate the three-dimensional motion of points in the field of view using multiple camera sequences. We use a scene flow algorithm to estimate the three-dimensional velocity at every point on a surface of the 10 June 2010 CME. We discuss how these technique can be used in future research.

Colaninno, R. C.; Vourlidas, A.

2010-12-01

241

Intracochlear Drug Delivery Systems  

PubMed Central

Introduction Advances in molecular biology and in the basic understanding of the mechanisms associated with sensorineural hearing loss and other diseases of the inner ear, are paving the way towards new approaches for treatments for millions of patients. However, the cochlea is a particularly challenging target for drug therapy, and new technologies will be required to provide safe and efficacious delivery of these compounds. Emerging delivery systems based on microfluidic technologies are showing promise as a means for direct intracochlear delivery. Ultimately, these systems may serve as a means for extended delivery of regenerative compounds to restore hearing in patients suffering from a host of auditory diseases. Areas covered in this review Recent progress in the development of drug delivery systems capable of direct intracochlear delivery is reviewed, including passive systems such as osmotic pumps, active microfluidic devices, and systems combined with currently available devices such as cochlear implants. The aim of this article is to provide a concise review of intracochlear drug delivery systems currently under development, and ultimately capable of being combined with emerging therapeutic compounds for the treatment of inner ear diseases. Expert Opinion Safe and efficacious treatment of auditory diseases will require the development of microscale delivery devices, capable of extended operation and direct application to the inner ear. These advances will require miniaturization and integration of multiple functions, including drug storage, delivery, power management and sensing, ultimately enabling closed-loop control and timed-sequence delivery devices for treatment of these diseases.

Borenstein, Jeffrey T.

2011-01-01

242

Commercial Document Delivery Services "Challenged" as EBSCO Drops Service.  

ERIC Educational Resources Information Center

Discusses the EBSCO decision to stop its traditional commercial document delivery business. High prices for copyright clearance, government subsidized services, electronic formats available on the Internet, Web-based services, and consortium-based licensing activities are discussed as influencing the market for document delivery. (LRW)

Machovec, George S.

1998-01-01

243

Non-Flux-Rope CME-Driven Shocks and Connection to Particle Acceleration in Solar 3He-Rich Events  

NASA Astrophysics Data System (ADS)

Two most significant space weather drivers that cause a wide range of severe effects on human activities are solar energetic particles (SEPs) and coronal mass ejections (CMEs). Observations at 1 AU indicated that the most frequently observed CMEs (about 2/3 of events) do not have flux-rope structure and the most frequently observed SEPs (about 1000 events per year) enrich their 3He abundances. 3He is a most important and clean fuel of thermonuclear fusion. It is rather rare on Earth, but its abundance is extremely enhanced in the satellite material and the Moon’s upper layer of the regolith due to the 3He-enrichments in SEP events. Recently, the initiation of CMEs without flux-rope topology have been simulated with a three-dimensional, time-dependent, self-consistent, flux emergence and reconnection, magnetohydrodynamic (MHD) model. This was done through emerging magnetic flux of one polarity from the photosphere, beneath the open field lines of the opposite polarity near the closed magnetic field lines. The results indicated that the magnetic flux emergence and reconnection can produce the magnetic topology that lead to solar 3He-rich events and generate jet-like plasma outflows, which may be further developed into CMEs without magnetic flux-rope topology if enough energy is deposited. This study examines the properties of non-flux-rope CME driven shocks and the connection to the particle acceleration in solar 3He-rich events.

Zhang, T.; Wu, S.

2010-12-01

244

An Asynchronous Augmentation to Traditional Course Delivery.  

ERIC Educational Resources Information Center

|Asynchronous augmentation facilitates distributed learning, which relies heavily on technology and self-learning. This paper reports the results of delivering a real estate principles course using an asynchronous course delivery format. It highlights one of many ways to enhance learning using technology, and it provides information concerning how…

Wolverton, Marvin L.; Wolverton, Mimi

245

One Quiz File, Several Modes of Delivery  

ERIC Educational Resources Information Center

|This report offers online course designers, particularly those keen on using Moodle CMSs, a means of diversifying accessibility to their educational materials via multiple modes of delivery that do not require the creation of numerous files and formats for just one activity. The author has made contributions to the development of an open source…

Herbert, John C.

2012-01-01

246

Iontophoretic delivery of apomorphine  

Microsoft Academic Search

Apomorphine is a mixed dopamine D1\\/D2 receptor agonist which is potentially useful in the treatment of Parkinson’s disease. The delivery of apomorphine is however complicated because it is not absorbed orally and other delivery routes with the exception of the intravenous route seem to fail. The most interesting route for controlled delivery of apomorphine is transdermal iontophoresis because this could

H. E Junginger

2002-01-01

247

Nonviral Vectors for Gene Delivery  

NASA Astrophysics Data System (ADS)

The development of nonviral vectors for safe and efficient gene delivery has been gaining considerable attention recently. An ideal nonviral vector must protect the gene against degradation by nuclease in the extracellular matrix, internalize the plasma membrane, escape from the endosomal compartment, unpackage the gene at some point and have no detrimental effects. In comparison to viruses, nonviral vectors are relatively easy to synthesize, less immunogenic, low in cost, and have no limitation in the size of a gene that can be delivered. Significant progress has been made in the basic science and applications of various nonviral gene delivery vectors; however, the majority of nonviral approaches are still inefficient and often toxic. To this end, two nonviral gene delivery systems using either biodegradable poly(D,L-lactide- co-glycolide) (PLG) nanoparticles or cell penetrating peptide (CPP) complexes have been designed and studied using A549 human lung epithelial cells. PLG nanoparticles were optimized for gene delivery by varying particle surface chemistry using different coating materials that adsorb to the particle surface during formation. A variety of cationic coating materials were studied and compared to more conventional surfactants used for PLG nanoparticle fabrication. Nanoparticles (˜200 nm) efficiently encapsulated plasmids encoding for luciferase (80-90%) and slowly released the same for two weeks. After a delay, moderate levels of gene expression appeared at day 5 for certain positively charged PLG particles and gene expression was maintained for at least two weeks. In contrast, gene expression mediated by polyethyleneimine (PEI) ended at day 5. PLG particles were also significantly less cytotoxic than PEI suggesting the use of these vehicles for localized, sustained gene delivery to the pulmonary epithelium. On the other hand, a more simple method to synthesize 50-200 nm complexes capable of high transfection efficiency or high gene knockdown was also explored. Positively charged CPPs were complexed with pDNA or siRNA, which resulted in 'loose' (˜1 micron) particles. These were then condensed into small nanoparticles by using calcium, which formed "soft" crosslinks by interacting with both phosphates on nucleic acids and amines on CPPs. An optimal amount of CaCl2 produced stable, ˜100 nm complexes that exhibited higher transfection efficiency and gene silencing than PEI polyplexes. CPPs also displayed negligible cytotoxicity up to 5 mg/mL. Biophysical studies of the pDNA structure within complexes suggested that pDNA within CPP complexes (condensed with calcium) had similar structure, but enhanced thermal stability compared to PEI complexes. Thus, CPP complexes emerged as simple, attractive candidates for future studies on nonviral gene delivery in vivo.

Baoum, Abdulgader Ahmed

248

Recovering Delivery for Digital Rhetoric  

Microsoft Academic Search

This article develops a rhetorical theory of delivery for Internet-based communications. Delivery, one of the five key canons of classical rhetoric, is still an important topic for rhetorical analysis and production. However, delivery needs to be re-theorized for the digital age. In Part 1, the article notes the importance of delivery in traditional rhetoric and argues that delivery should be

James E. Porter

2009-01-01

249

[The moon and delivery].  

PubMed

In different cultures and mythologies, the moon is related with fertility, pregnancy and delivery. Professional obstetricians also notice an increase in care demands on the days when the moon is full. Many studies have been made which try to correlate delivery processes to the phases of the moon with contradictory results. The authors plan to try to find any basis in fact which support these popular beliefs and to discover if lunar phases bear an influence on the distribution of deliveries. They carried out a descriptive transversal study on a total of 1715 unassisted deliveries over the course of ten complete lunar cycles. The authors have carried out a descriptive and inferential analysis, a one way ANOVA and a Kruskal Wallis test on their three data bases which are general, primipara and multipara in which they contemplated the total number of deliveries per phase, the mean of each phase, as well as the central day in each phase of the lunar cycle. The differences found in the distribution of deliveries over the four lunar phases, along with the comparison of the means and the comparison of the number of deliveries on the central day in each phase are not statistically significant. The different phases in the lunar cycle and especially the full moon do not appear to have any influence over the distribution of deliveries in this study. PMID:15648892

Romero Martínez, Jorge; Guerrero Guijo, Inmaculada; Artura Serrano, Antonio

2004-11-01

250

Community Digital Library Requirements for the Southern California Earthquake Center Community Modeling Environment (SCEC/CME)  

NASA Astrophysics Data System (ADS)

A community digital library provides support for ingestion, organization, description, preservation, and access of digital entities. The technologies that traditionally provide these capabilities are digital libraries (ingestion, organization, description), persistent archives (preservation) and data grids (access). We present a design for the SCEC community digital library that incorporates aspects of all three systems. Multiple groups have created integrated environments that sustain large-scale scientific data collections. By examining these projects, the following stages of implementation can be identified: \\begin{itemize} Definition of semantic terms to associate with relevant information. This includes definition of uniform content descriptors to describe physical quantities relevant to the scientific discipline, and creation of concept spaces to define how the uniform content descriptors are logically related. Organization of digital entities into logical collections that make it simple to browse and manage related material. Definition of services that are used to access and manipulate material in the collection. Creation of a preservation environment for the long-term management of the collection. Each community is faced with heterogeneity that is introduced when data is distributed across multiple sites, or when multiple sets of collection semantics are used, and or when multiple scientific sub-disciplines are federated. We will present the relevant standards that simplify the implementation of the SCEC community library, the resource requirements for different types of data sets that drive the implementation, and the digital library processes that the SCEC community library will support. The SCEC community library can be viewed as the set of processing steps that are required to build the appropriate SCEC reference data sets (SCEC approved encoding format, SCEC approved descriptive metadata, SCEC approved collection organization, and SCEC managed storage location). Each digital entity that is ingested into the SCEC community library is processed and validated for conformance to SCEC standards. These steps generate provenance, descriptive, administrative, structural, and behavioral metadata. Using data grid technology, the descriptive metadata can be registered onto a logical name space that is controlled and managed by the SCEC digital library. A version of the SCEC community digital library is being implemented in the Storage Resource Broker. The SRB system provides almost all the features enumerated above. The peer-to-peer federation of metadata catalogs is planned for release in September, 2003. The SRB system is in production use in multiple projects, from high-energy physics, to astronomy, to earth systems science, to bio-informatics. The SCEC community library will be based on the definition of standard metadata attributes, the creation of logical collections within the SRB, the creation of access services, and the demonstration of a preservation environment. The use of the SRB for the SCEC digital library will sustain the expected collection size and collection capabilities.

Moore, R.; Faerman, M.; Minster, J.; Day, S. M.; Ely, G.

2003-12-01

251

Novel gene delivery systems  

PubMed Central

Gene therapy is an emerging field in medical and pharmaceutical sciences because of its potential in treating chronic diseases like cancer, viral infections, myocardial infarctions, and genetic disorders. Application of gene therapy is limited because of lack of suitable methods for proper introduction of genes into cells and therefore, this is an area of interest for most of the researchers. To achieve successful gene therapy, development of proper gene delivery systems could be one of the most important factors. Several nonviral and viral gene transfer methods have been developed. Even though the viral agents have a high transferring efficiency, they are difficult to handle due to their toxicity. To overcome the safety problems of the viral counterpart, several nonviral in vitro and in vivo gene delivery systems are developed. Out of these, the most promising and latest systems include polymer-based nonviral gene carriers, dendrimers, and physical means like electroporation, microinjection, etc., Shunning of possible immunogenicity and toxicity, and the feasibility of repeated administration are some of the merits of nonviral gene delivery systems over viral gene delivery. An ideal nonviral gene carrying system should possess all these merits without any compromise to its gene transferring efficiency. The viral gene delivery systems include lytic and nonlytic vectors for drug delivery. Inspite of its toxicity they are still preferred because of their long term expression, stability, and integrity. This review explores the recent developments and relevancy of the novel gene delivery systems in gene therapy.

Manjila, Steffy B; Baby, Jomon N; Bijin, Elambilan N; Constantine, Icey; Pramod, Kannissery; Valsalakumari, Janardhanan

2013-01-01

252

Speed Evolution of Fast CME/Shocks with SOHO/LASCO, Wind/WAVES, IPS and in-situ WIND data: Analysis of Kilometric Type-II Emissions (Invited)  

NASA Astrophysics Data System (ADS)

Fast CME/shocks propagating in the interplanetary medium can generate kilometric Type II (km-TII) radio emissions at the local plasma frequency and/or its harmonic, so these radio emissions provide a means of remotely tracking CME/shocks. We apply a new analysis technique, using the frequency drift of km-TII spectrum obtained by the Thermal Noise Receiver (TNR) of the WIND/WAVES experiment, to infer, at some adequate intervals, the propagation speed of six CME/shocks. We combine these results with previously reported speeds from coronagraph white light and interplanetary scintillation observations, and in-situ measurements, to study the temporal speed evolution of the six events. The shock speed values obtained by the km-TII analysis are in a reasonable agreement with the speed measurements inferred by other techniques at different heliocentric distance ranges. The combination of all the speed measurements show a gradual deceleration of the CME/shocks as they propagate to 1 AU. This new technique can be useful in studying the evolution of fast CME/shocks when adequate intervals of km-TII emissions are available.

Gonzalez-Esparza, A.

2009-12-01

253

Vacuum-assisted delivery.  

PubMed

The literature seems to allow certain general conclusions regarding the choice of instrument for assisted vaginal delivery. Both forceps and vacuum extraction offer certain advantages and drawbacks. Forceps are more difficult to apply, more prone to potentially significant facial injuries, require generally better maternal analgesia, and are associated with increased maternal soft tissue trauma. Vacuum extractors in general are easier to apply, are more likely to result in scalp trauma, and may be associated with increased rates of intracranial trauma. It seems likely that factors particular to each patient may play a significant role in the genesis of delivery associated with maternal and neonatal morbidity. Because of the ease of application, vacuum extractors may be used potentially in circumstances in which forceps assistance would not be attempted, allowing an operator of average experience to perform rotational deliveries. The use of vacuum extraction does appear to decrease the incidence of cesarean section in delivery populations. Given the apparent association between difficult assisted deliveries and increased neonatal morbidity, it is incumbent on the operator to attempt delivery only when vaginal delivery seems to be a safe option. Furthermore, the operator in such circumstances must be willing to reassess the attempt if initial attempts are not met with success. The minimal rates of significant intracranial injury associated with vacuum extraction in randomized studies of the method demonstrate the relative safety of the vacuum extraction when used judiciously. The ultimate choice of the route of delivery and method of assisted delivery should reflect a consideration of the fetal station, presentation, and maternal and fetal circumstances. It is hoped that further investigations in this area may clarify some of the issues discussed in this article. PMID:8665766

Williams, M C

1995-12-01

254

Microsponge delivery system.  

PubMed

Microsponges are polymeric delivery systems consisting of porous microspheres having a size range in between 5 to 300 microm depending upon the degree of smoothness or after feel required for the end formulations. Microsponge Delivery System MDS is a unique technology for controlled delivery of drug. The present review introduces Microsponge technology along with its synthesis, characterization, programmable parameters and release mechanism of MDS. Wide ranges of applications are also suggested to develop drug or cosmetic products with enhanced safety and efficacy. MDS can provide increased efficacy for topically active agents with enhanced safety, extended product stability and improved aesthetic properties in an efficient and novel manner. PMID:17456031

Chadawar, Vikrant; Shaji, Jessy

2007-04-01

255

Optically generated ultrasound for enhanced drug delivery  

DOEpatents

High frequency acoustic waves, analogous to ultrasound, can enhance the delivery of therapeutic compounds into cells. The compounds delivered may be chemotherapeutic drugs, antibiotics, photodynamic drugs or gene therapies. The therapeutic compounds are administered systemically, or preferably locally to the targeted site. Local delivery can be accomplished through a needle, cannula, or through a variety of vascular catheters, depending on the location of routes of access. To enhance the systemic or local delivery of the therapeutic compounds, high frequency acoustic waves are generated locally near the target site, and preferably near the site of compound administration. The acoustic waves are produced via laser radiation interaction with an absorbing media and can be produced via thermoelastic expansion, thermodynamic vaporization, material ablation, or plasma formation. Acoustic waves have the effect of temporarily permeabilizing the membranes of local cells, increasing the diffusion of the therapeutic compound into the cells, allowing for decreased total body dosages, decreased side effects, and enabling new therapies.

Visuri, Steven R. (Livermore, CA); Campbell, Heather L. (Baltimore, MD); Da Silva, Luiz (Danville, CA)

2002-01-01

256

Educational Telecommunications Delivery Systems.  

National Technical Information Service (NTIS)

This monograph is a single volume reference manual providing an overall review of the current status and likely near future application of six major educational telecommunications delivery technologies. The introduction provides an overview to the usage a...

J. A. Curtis J. M. Biedenbach

1979-01-01

257

Implantable Insulin Delivery System.  

National Technical Information Service (NTIS)

An insulin delivery system suitable for experimental implants and external use has been developed to study glucose control for diabetics. The programmable system developed at Sandia National Laboratories, in conjunction with the University of New Mexico S...

J. T. Love J. I. Gaona

1981-01-01

258

Project Delivery Methods.  

ERIC Educational Resources Information Center

|Describes project delivery methods that are replacing the traditional Design/Bid/Build linear approach to the management, design, and construction of new facilities. These variations can enhance construction management and teamwork. (SLD)|

Dolan, Thomas G.

2003-01-01

259

Integrated Service Delivery Report.  

National Technical Information Service (NTIS)

A demonstration project undertaken by the State of Washington Department of Social and Health Services to determine the value of integrated service delivery systems in terms of the appropriateness, accessibility, effectiveness, and cost of services is doc...

1975-01-01

260

Bacterial delivery system  

US Patent & Trademark Office Database

We describe a bacterial delivery system for the delivery of DNA and antigens into cells. We constructed an attenuated bacterial vector which enters mammalian cells and ruptures delivering functional plasmid DNA and antigens into the cell cytoplasm. This Shigella vector was designed to deliver DNA to colonic surfaces, thus opening the possibility of oral and other mucosal DNA immunization and gene therapy strategies. The attenuated Shigella is also useful as a vaccine for reducing disease symptoms caused by Shigella.

Branstrom; Arthur A. (Rockville, MD); Sizemore; Donata R. (Gaithersburg, MD); Sadoff; Jerald C. (Washington, DC)

2006-05-16

261

Nanoparticles for Pulmonary Delivery  

Microsoft Academic Search

\\u000a This chapter aims to provide a rational for the use of nanoparticles in pulmonary delivery as well as an overview of strategies\\u000a and physiological implications of nanoparticle delivery to the lungs. Formulation aspects of nanoparticle systems in the form\\u000a of liquid dispersions and inhaled dry powders are also reviewed. The chapter also addresses the expanse of lung toxicology\\u000a research surrounding

Alan B. Watts; Robert O. Williams

262

Vacuum actuated gas delivery  

Microsoft Academic Search

The new Vacuum Actuated Cylinder (VACTM) gas source provides sub-atmospheric pressure delivery of the metal fluorides commonly used as dopants for ion implant. The VAC gas source is a mechanical system based on an embedded pressure control device located inside the cylinder. A pre-set sub-atmospheric pressure must be achieved in the delivery manifold before flow is permitted from the cylinder.

W. K. Olander; M. Donatucci; J. Mayer; L. Wang

2000-01-01

263

Failed Operative Vaginal Delivery  

PubMed Central

Objective To compare maternal and neonatal outcomes in women undergoing a second stage cesarean after a trial of operative vaginal delivery with women undergoing a second stage cesarean without such an attempt. Methods This study is a secondary analysis of the women who underwent second stage cesarean. .The maternal outcomes examined included blood transfusion, endometritis, wound complication, anesthesia use, and maternal death. Infant outcomes examined included umbilical artery pH < 7.0, Apgar of 3 or less at 5 minutes, seizures within 24 hours of birth, hypoxic ischemic encephalopathy (HIE), stillbirth, skull fracture, and neonatal death. Results Of 3189 women who underwent second stage cesarean, operative vaginal delivery was attempted in 640. Labor characteristics were similar in the two groups with the exception of the admission to delivery time and cesarean indication. Those with an attempted operative vaginal delivery were more likely to undergo cesarean delivery for a non-reassuring fetal heart rate tracing (18.0% vs 13.9%, p=.01), have a wound complication (2.7% vs 1.0%; OR 2.65 95% CI 1.43–4.91), and require general anesthesia (8.0% vs 4.1%, OR 2.05 95% CI 1.44–2.91). Neonatal outcomes including umbilical artery pH less than 7.0, Apgar at or below 3 at 5 minutes, and hypoxic ischemic encephalopathy were more common for those with an attempted operative vaginal delivery. This was not significant when cases with a non-reassuring fetal heart rate tracing were removed. Conclusion Cesarean delivery after an attempt at operative vaginal delivery was not associated with adverse neonatal outcomes in the absence of a non-reassuring fetal heart rate tracing.

Alexander, James M.; Leveno, Kenneth J.; Hauth, John C.; Landon, Mark B.; Gilbert, Sharon; Spong, Catherine Y.; Varner, Michael W.; Caritis, Steve N.; Meis, Paul; Wapner, Ronald J.; Sorokin, Yoram; Miodovnik, Menachem; O'Sullivan, Mary J.; Sibai, Baha M.; Langer, Oded; Gabbe, Steven G.

2010-01-01

264

Nanotechnologies in protein delivery.  

PubMed

The growth rate for biotech drugs, namely proteins, peptides, and oligonucleotides, is dictated by the parallel progresses in biotechnology and nanotechnology. Actually, biotechnology techniques have expanded enormously the arsenal of therapeutically useful peptides and proteins making these products of primary interest for future pharmaceutical market. Nevertheless, the exploitation of protein and peptide drugs is strictly related to the development of innovative delivery systems which should provide for controlled, prolonged, or targeted delivery, improved stability during storage and delivery, reduced adverse effects, increased bioavailability, improved patient compliance and allow for administration through the desired route and cope with cost-containment therapeutic protocols. Colloidal formulations ideally possess the physicochemical and biopharmaceutical requisites for protein delivery. Pharmaceutical nanotechnology is a tool of techniques applied to design, develop and produce these systems. It involves the investigation of innovative materials and production procedures for preparation of a variety of nanosized dosage forms, which range from solid nanoparticles to soluble bioconjugates. The research and development of innovative tailor made protein delivery systems, which must be designed according to the drug candidate pharmacological and physicochemical properties, is one of the primary aim of modern pharmaceutical technology. Therefore, as an unmet need exists for technologies that combine innovative drug delivery solutions, a close un-prejudicial interaction between academic and industrial researchers as well as business thought leaders is required. PMID:17048478

Salmaso, Stefano; Bersani, Sara; Semenzato, Alessandra; Caliceti, Paolo

265

MAGNETOHYDRODYNAMIC MODELING FOR A FORMATION PROCESS OF CORONAL MASS EJECTIONS: INTERACTION BETWEEN AN EJECTING FLUX ROPE AND AN AMBIENT FIELD  

SciTech Connect

We performed a magnetohydrodynamic simulation of a formation process of coronal mass ejections (CMEs), focusing on the interaction (reconnection) between an ejecting flux rope and its ambient field. We examined three cases with different ambient fields: one had no ambient field, while the other two had dipole fields with opposite directions, parallel and anti-parallel to that of the flux rope surface. We found that while the flux rope disappears in the anti-parallel case, in the other cases the flux ropes can evolve to CMEs and show different amounts of flux rope rotation. The results imply that the interaction between an ejecting flux rope and its ambient field is an important process for determining CME formation and CME orientation, and also show that the amount and direction of the magnetic flux within the flux rope and the ambient field are key parameters for CME formation. The interaction (reconnection) plays a significant role in the rotation of the flux rope especially with a process similar to 'tilting instability' in a spheromak-type experiment of laboratory plasma.

Shiota, Daikou [Advanced Science Institute, RIKEN (Institute of Physics and Chemical Research), Wako, Saitama 351-0198 (Japan); Kusano, Kanya [Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Miyoshi, Takahiro [Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Shibata, Kazunari, E-mail: shiota@riken.j [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

2010-08-01

266

Turkey. [CME Country Reports].  

ERIC Educational Resources Information Center

|Since 1960, approximately 733,000 Turkish workers have migrated to European countries. One issue before the Turkish Government is adequately educating children of Turkish migrant workers in other countries. There are more than 117,000 children who are expected to retain their traditional Turkish culture while adjusting themselves to the host…

Council of Europe, Strasbourg (France). Documentation Center for Education in Europe.

267

DETERMINATION OF THE HELIOSPHERIC RADIAL MAGNETIC FIELD FROM THE STANDOFF DISTANCE OF A CME-DRIVEN SHOCK OBSERVED BY THE STEREO SPACECRAFT  

SciTech Connect

We report on the determination of radial magnetic field strength in the heliocentric distance range from 6 to 120 solar radii (R {sub Sun }) using data from Coronagraph 2 (COR2) and Heliospheric Imager I (HI1) instruments on board the Solar Terrestrial Relations Observatory spacecraft following the standoff-distance method of Gopalswamy and Yashiro. We measured the shock standoff distance of the 2008 April 5 coronal mass ejection (CME) and determined the flux-rope curvature by fitting the three-dimensional shape of the CME using the Graduated Cylindrical Shell model. The radial magnetic field strength is computed from the Alfven speed and the density of the ambient medium. We also compare the derived magnetic field strength with in situ measurements made by the Helios spacecraft, which measured the magnetic field at the heliocentric distance range from 60 to 215 R {sub Sun }. We found that the radial magnetic field strength decreases from 28 mG at 6 R {sub Sun} to 0.17 mG at 120 R {sub Sun }. In addition, we found that the radial profile can be described by a power law.

Poomvises, Watanachak; Gopalswamy, Nat; Yashiro, Seiji; Kwon, Ryun-Young [NASA GSFC, Greenbelt, MD 20771 (United States); Olmedo, Oscar [Space Science Division, U.S. Naval Research Laboratory, Washington, DC 20375 (United States)

2012-10-20

268

On the Vector Tomographic Reconstruction for the pre-CME Coronal Magnetic Field from Fe XIII 10747 A Emission Line Observations  

NASA Astrophysics Data System (ADS)

Magnetic fields are the dominant fields that determine the static and dynamic properties of the solar corona. The coronal mass ejections (CMEs) involve the release of the magnetic energy stored in the magnetic field. Therefore, analyzing the magnetic field could help to understand the nature of CMEs. One of the more promising coronal magnetic field measurement methods that have been successfully demonstrated is the spectropolarimetric observations of the Fe XIII 10747 A forbidden emission line (Lin, Penn & Tomczyk 2000; Lin, Kuhn & Coulter 2004; Tomczyk et al. 2007) formed due to Hanle and Zeeman effects. However, these measurements are integrated over line-of-sight (LOS). Therefore it is impossible to determine the configuration of the coronal magnetic field from a single observation (single viewing direction). Vector tomography based on polarimetric observations of the forbidden coronal emission lines can reconstruct the coronal magnetic field when the observations are obtained from several viewing directions. As the tomography method requires observations from many directions, a rigid rotation of the coronal structures during a half of solar rotation is assumed. However, many pre-CME magnetic configurations evolve more rapidly causing significant reduce in the number of available observing directions. Here we study the sensitivity of the vector tomographic inversion to possible pre-CME coronal magnetic field configurations and the number of available observing directions. We show that the vector tomography techniques has the potential to resolve the 3D coronal non-potential magnetic field structure.

Kramar, Maxim; Lin, H.; Inhester, B.; Davila, J.

2010-05-01

269

Coronal Shock Waves, EUV Waves, and Their Relation to CMEs. III. Shock-Associated CME/EUV Wave in an Event with a Two-Component EUV Transient  

NASA Astrophysics Data System (ADS)

On 17 January 2010, STEREO-B observed in extreme ultraviolet (EUV) and white light a large-scale dome-shaped expanding coronal transient with perfectly connected off-limb and on-disk signatures. Veronig et al. (Astrophys. J. Lett. 716, L57, 2010) concluded that the dome was formed by a weak shock wave. We have revealed two EUV components, one of which corresponded to this transient. All of its properties found from EUV, white light, and a metric type II burst match expectations for a freely expanding coronal shock wave, including correspondence with the fast-mode speed distribution, while the transient sweeping over the solar surface had a speed typical of EUV waves. The shock wave was presumably excited by an abrupt filament eruption. Both a weak shock approximation and a power-law fit match kinematics of the transient near the Sun. Moreover, the power-law fit matches the expansion of the CME leading edge up to 24 solar radii. The second, quasi-stationary EUV component near the dimming was presumably associated with a stretched CME structure; no indications of opening magnetic fields have been detected far from the eruption region.

Grechnev, V. V.; Afanasyev, A. N.; Uralov, A. M.; Chertok, I. M.; Eselevich, M. V.; Eselevich, V. G.; Rudenko, G. V.; Kubo, Y.

270

Coronal Shock Waves, EUV Waves, and Their Relation to CMEs. III. Shock-Associated CME/EUV Wave in an Event with a Two-Component EUV Transient  

NASA Astrophysics Data System (ADS)

On 17 January 2010, STEREO-B observed in extreme ultraviolet (EUV) and white light a large-scale dome-shaped expanding coronal transient with perfectly connected off-limb and on-disk signatures. Veronig et al. ( Astrophys. J. Lett. 716, L57, 2010) concluded that the dome was formed by a weak shock wave. We have revealed two EUV components, one of which corresponded to this transient. All of its properties found from EUV, white light, and a metric type II burst match expectations for a freely expanding coronal shock wave, including correspondence with the fast-mode speed distribution, while the transient sweeping over the solar surface had a speed typical of EUV waves. The shock wave was presumably excited by an abrupt filament eruption. Both a weak shock approximation and a power-law fit match kinematics of the transient near the Sun. Moreover, the power-law fit matches the expansion of the CME leading edge up to 24 solar radii. The second, quasi-stationary EUV component near the dimming was presumably associated with a stretched CME structure; no indications of opening magnetic fields have been detected far from the eruption region.

Grechnev, V. V.; Afanasyev, A. N.; Uralov, A. M.; Chertok, I. M.; Eselevich, M. V.; Eselevich, V. G.; Rudenko, G. V.; Kubo, Y.

2011-11-01

271

The cyclo Sal-Nucleotide Delivery System  

Microsoft Academic Search

Pronucleotides represent a promising alternative to improve the biological activity of nucleoside analogs against different\\u000a viral diseases and cancer chemotherapy. Moreover, pronucleotides are valuable tools for studies concerning nucleoside\\/nucleotide\\u000a metabolism. The basic idea is to achieve nucleotide delivery into cells, bypassing limitations with intracellular formation\\u000a of nucleotides from their nucleoside precursors. The cycloSaligenyl (cycloSal) concept is one of several pronucleotide

Chris Meier; Jan Balzarini; Astrid Meerbach

272

Protein microspheres for pulmonary drug delivery  

Microsoft Academic Search

A new supercritical fluid (SCF) technique was developed for the preparation of microspheres for pulmonary drug delivery (PDD).\\u000a This technique, based on the anti-solvent process, has incorporated advanced engineering design features to enable improved\\u000a control of the particle formation process. Human recombinant insulin (HRI) was used as a model compound to evaluate the efficiency\\u000a of this SCF process. An aqueous

Yongda Sun

2010-01-01

273

Changes in Altitude Cause Unintended Insulin Delivery From Insulin Pumps  

PubMed Central

OBJECTIVE Children and adults with type 1 diabetes who receive insulin pump therapy have reported hypoglycemia during air travel. We studied the effects of atmospheric pressure on insulin pump delivery. RESEARCH DESIGN AND METHODS Ten insulin pumps were connected to capillary tubes. The effects of changes in ambient pressure on insulin delivery, bubble formation, bubble size, and cartridge plunger movement were analyzed. RESULTS During a flight (200 mmHg pressure decrease), excess insulin delivery of 0.623% of the cartridge volume occurred (P < 0.001, Student t test). In hypobaric chamber studies, bubbles developed in the insulin when the pressure decreased and displaced the insulin out of the cartridge. Pre-existing bubbles changed in size consistent with Boyle law. Cartridge plunger movement did not occur in normal flight conditions but did occur when catastrophic plane depressurization was mimicked. CONCLUSIONS Atmospheric pressure reduction causes predictable, unintended insulin delivery in pumps by bubble formation and expansion of existing bubbles.

King, Bruce R.; Goss, Peter W.; Paterson, Megan A.; Crock, Patricia A.; Anderson, Donald G.

2011-01-01

274

Automated infrastructure delivery system  

US Patent & Trademark Office Database

An automatic delivery system for an infrastructure comprising passenger transportation, freight delivery, electrical grid, oil, gas, water pipelines, communication, sewer removal, etc. The automation at the current state of technology is mostly achieved by enclosing the delivery system inside of an enclosure for achieving automatic weather independent transportation and eliminating costs related to protecting the aforementioned infrastructure components from outside elements. In addition, the system is simple enough to avoid traffic and collisions automatically by processing in real time just a single piece of information: a location of each vehicle; as the result, the system is inexpensive since no hardware is necessary for between-vehicles communications, for road condition detection, for GPS, etc. Plus every person will be able to use transportation on-demand with or without sharing a commute and at a desired comfort level including but not limited to entertainment, exercise, working on the go, etc.

2013-06-04

275

Matrix-based gene delivery for tissue repair.  

PubMed

Scaffolds for tissue repair must provide structural and biochemical cues to initiate the complex cascade of events that lead to proper tissue formation. Incorporating genes into these scaffolds is an attractive alternative to protein delivery since gene delivery can be tunable to any DNA sequence and genes utilize the cells' machinery to continuously produce therapeutic proteins, leading to longer lasting transgene expression and activation of autocrine and paracrine signaling that are not activated with bulk protein delivery. In this review, we discuss the importance of scaffold design and the impact of its design parameters (e.g. material, architecture, vector incorporation, biochemical cue presentation) on transgene expression and tissue repair. PMID:23680305

Cam, Cynthia; Segura, Tatiana

2013-05-14

276

Lentivirus delivery by adsorption to tissue engineering scaffolds  

PubMed Central

Biomaterial scaffolds capable of localized gene delivery are being investigated for numerous regenerative medicine applications and as model systems for fundamental studies of tissue formation. In this manuscript, we investigate the delivery of lentivirus from a tissue engineering scaffold using a surface immobilization strategy. PLG was employed as the biomaterial for delivery, which has been widely used for a number of tissue engineering applications. The virus was immobilized by freezing and subsequent lyophilization of the virus with the scaffold. The presence of sucrose during freezing and lyophilization maintained the activity of the lentivirus, and was similar to an adenovirus control. Collagen and fibronectin were investigated for their ability to enhance surface immobilization. Fibronectin modestly increased binding and transduction of the adenovirus, yet did not significantly impact the lentivirus delivery. Most of the immobilized lentivirus was released from the scaffold within 24 hours. In vivo implantation of the scaffolds yielded transgene expression that persisted for at least 4 weeks. These findings indicate the potential for delivering lentivirus from tissue engineering scaffolds using a surface immobilization strategy. To our knowledge, this report is the first to investigate lentivirus delivery from porous tissue engineering scaffolds. Delivery of lentiviral vectors from PLG scaffolds could provide an efficient and versatile gene delivery system for use with in vitro and in vivo models of tissue formation, and ultimately for therapeutic applications.

Shin, Seungjin; Salvay, David M.; Shea, Lonnie D.

2009-01-01

277

Systems and Components Fuel Delivery System, Water Delivery System, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur , Huntsville, Madison County, AL

278

The Development of Standards to Ensure the Competency of Physician Assistants. Volume V: The Design of a System of Accreditation and Maintenance of a Roster of CME Programs for Physician Assistants.  

National Technical Information Service (NTIS)

The purpose of this project was to suggest modifications in the design or emphasis of the system of accreditation of group-oriented continuing medical education (CME) programs maintained by the American Academy of Physician Assistants. To do that, a syste...

1979-01-01

279

GENE DELIVERY TO BONE  

PubMed Central

Gene delivery to bone is useful both as an experimental tool and as a potential therapeutic strategy. Among its advantages over protein delivery are the potential for directed, sustained and regulated expression of authentically processed, nascent proteins. Although no clinical trials have been initiated, there is a substantial pre-clinical literature documenting the successful transfer of genes to bone, and their intraosseous expression. Recombinant vectors derived from adenovirus, retrovirus and lentivirus, as well as non-viral vectors, have been used for this purpose. Both ex vivo and in vivo strategies, including gene-activated matrices, have been explored. Ex vivo delivery has often employed mesenchymal stem cells (MSCs), partly because of their ability to differentiate into osteoblasts. MSCs also have the potential to home to bone after systemic administration, which could serve as a useful way to deliver transgenes in a disseminated fashion for the treatment of diseases affecting the whole skeleton, such as osteoporosis or osteogenesis imperfecta. Local delivery of osteogenic transgenes, particularly those encoding bone morphogenetic proteins, has shown great promise in a number of applications where it is necessary to regenerate bone. These include healing large segmental defects in long bones and the cranium, as well as spinal fusion and treating avascular necrosis.

Evans, C. H.

2012-01-01

280

Optimized Aerial Delivery Process.  

National Technical Information Service (NTIS)

In 2009 and 2010, the Aerial Delivery function at Little Rock Air Force Base experienced periodic surges in training load demand that could not be met under the current supply chain. Critical to the training of aircrew on base spanning three Major Command...

K. Kostrubala

2011-01-01

281

Document Delivery Expert.  

ERIC Educational Resources Information Center

|Describes the design of an expert system developed using VP-Expert for document delivery decision making in a law library. Presents methods used in knowledge acquisition and knowledge representation after a brief review of the literature on expert system use in libraries. An appendix includes the rules of the expert system. (Author/AEF)|

Abate, Anne K.

1995-01-01

282

Comprehensive Human Services Delivery System.  

National Technical Information Service (NTIS)

The comprehensive human service delivery system for Los Angeles County, California is detailed. The Comprehensive Employment and Training Act (CETA) of 1973 resulted in the funding of programs in Los Angeles County for human service delivery. Objectives o...

1975-01-01

283

Local magnetism in the molecule-based metamagnet [Ru2(O2CMe)4]3[Cr(CN)6] probed with implanted muons  

SciTech Connect

We present a muon-spin relaxation study of local magnetism in the molecule-based metamagnet [Ru2(O2CMe)4]3[Cr(CN)6]. We observe magnetic order with TN = 33 K, although above 25 K the sublattice spins become less rigid and a degree of static magnetic disorder is observed. The comparison of measurements in applied magnetic field with simulations allows us to understand the origin of the muon response across the metamagnetic transition and to map out the phase diagram of the material. Applied hydrostatic pressures of up to 6 kbar lead to an increase in the local magnetic field along with a complex change in the internal magnetic field distribution.

Lancaster, T. [University of Oxford; Pratt, F. L. [ISIS Facility, Rutherford Appleton Laboratory; Blundell, S. J. [University of Oxford; Steele, Andrew J. [University of Oxford; Baker, Peter J. [ISIS Facility, Rutherford Appleton Laboratory; Wright, Jack D. [University of Oxford; Fishman, Randy Scott [ORNL; Miller, Joel S. [University of Utah

2011-01-01

284

Sustained Release Intravitreal Liquid Drug Delivery Using Triamcinolone Acetonide for Cystoid Macular Edema in Retinal Vein Occlusion  

PubMed Central

Purpose To investigate side effects seen with this formulation and to search for evidence of effectiveness after a single intravitreal injection of IBI-20089 in eyes with cystoid macular edema (CME) secondary to retinal vein occlusion. Design Prospective phase 1 clinical trial Participants 10 patients with chronic CME due to retinal vein occlusion Methods Patients received a single intravitreal injection of IBI-20089 using a sequential dose escalation schedule. Each cohort consisted of five patients who received the intravitreal injection of the sustained liquid drug delivery system containing either 6.9 mg (25 ul) triamcinolone acetonide (TA) (Cohort 1) or 13.8 mg (50 ul) TA (Cohort 2). At each study visit, best corrected visual acuity testing, slit lamp biomicroscopy, intraocular pressure (IOP) measurement, dilated ophthalmoscopy, fundus photography and optical coherence tomography (OCT) were performed. Patients also underwent laboratory testing and physical examinations to monitor for any systemic adverse events. Main Outcome measures OCT central subfield thickness, ocular and systemic adverse events Results In Cohort 1, mean baseline OCT central subfield thickness (CST) was 477 microns (?) and decreased to 369 ? at day 1 (p< 0.06), 387 ? at day 30 (p= 0.18) and 251 ? at day 360 (p=0.46). In Cohort 2, mean baseline OCT CST was 518 ?, and decreased to 404 ? at day 1 (p=0.134), 289 ? at day 30 (p=0.003), 207 ? at day180 (p=0.004) and 278 ? at day 360 (p=0.009). Related adverse events included elevation of IOP in three patients; two due to neovascular glaucoma (not related to study drug) and one which required a glaucoma tube shunt. Conclusion A single intravitreal injection of IBI-20089 resulted in a controlled and sustained delivery of a TA. Side effects included elevated IOP in three eyes, two of which had neovascular glaucoma.

Lim, Jennifer I.; Fung, Anne E.; Wieland, Mark; Hung, Dean; Wong, Vernon

2013-01-01

285

Needle-free vaccine delivery  

Microsoft Academic Search

The search for methods of vaccine delivery not requiring a needle and syringe has been accelerated by recent concerns regarding pandemic disease, bioterrorism, and disease eradication campaigns. Needle-free vaccine delivery could aid in these mass vaccinations by increasing ease and speed of delivery, and by offering improved safety and compliance, decreasing costs, and reducing pain associated with vaccinations. In this

Erin L. Giudice; James D. Campbell

2006-01-01

286

Ultrasound and transdermal drug delivery  

Microsoft Academic Search

Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injection. However, the stratum corneum acts as a barrier that limits the penetration of substances through the skin. Application of ultrasound to the skin increases its permeability (sonophoresis) and enables the delivery of various substances into and through the skin. This review presents

Ilana Lavon; Joseph Kost

2004-01-01

287

Drug delivery to damaged brain  

Microsoft Academic Search

Drug delivery to the brain poses unique challenges. Specialized anatomic and physiological features of the cerebrovasculature and cerebral tissue fluids result in barriers which significantly restrict delivery of a wide range of possible therapeutic agents. In addition to these normal restrictions to brain drug delivery, pathophysiological features and sequelae of acute brain injury will also impact upon the efficiency of

Eng H. Lo; Aneesh B. Singhal; Vladimir P. Torchilin; N. Joan Abbott

2001-01-01

288

PECTIN IN CONTROLLED DRUG DELIVERY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Controlled drug delivery remains a research focus for public health to enhance patient compliance, drug efficiency and to reduce the side effects of drugs. Pectin, an edible plant polysaccharide, has shown potential for the construction of drug delivery systems for site-specific drug delivery. Sev...

289

Cyclodextrins in nasal drug delivery  

Microsoft Academic Search

Nasal drug delivery is an attractive approach for the systemic delivery of high potency drugs with a low oral bioavailability due to extensive gastrointestinal breakdown and high hepatic first-pass effect. For lipophilic drugs nasal delivery is possible if they can be dissolved in the dosage form. Peptide and protein drugs often have a low nasal bioavailability because of their large

F. W. H. M Merkus; J. C Verhoef; E Marttin; S. G Romeijn; P. H. M van der Kuy; W. A. J. J Hermens; N. G. M Schipper

1999-01-01

290

Peptide and protein delivery using new drug delivery systems.  

PubMed

Pharmaceutical and biotechnological research sorts protein drug delivery systems by importance based on their various therapeutic applications. The effective and potent action of the proteins/peptides makes them the drugs of choice for the treatment of numerous diseases. Major research issues in protein delivery include the stabilization of proteins in delivery devices and the design of appropriate target-specific protein carriers. Many efforts have been made for effective delivery of proteins/peptidal drugs through various routes of administrations for successful therapeutic effects. Nanoparticles made of biodegradable polymers such as poly lactic acid, polycaprolactone, poly(lactic-co-glycolic acid), the poly(fumaric-co-sebacic) anhydride chitosan, and modified chitosan, as well as solid lipids, have shown great potential in the delivery of proteins/peptidal drugs. Moreover, scientists also have used liposomes, PEGylated liposomes, niosomes, and aquasomes, among others, for peptidal drug delivery. They also have developed hydrogels and transdermal drug delivery systems for peptidal drug delivery. A receptor-mediated delivery system is another attractive strategy to overcome the limitation in drug absorption that enables the transcytosis of the protein across the epithelial barrier. Modification such as PEGnology is applied to various proteins and peptides of the desired protein and peptides also increases the circulating life, solubility and stability, pharmacokinetic properties, and antigenicity of protein. This review focuses on various approaches for effective protein/peptidal drug delivery, with special emphasis on insulin delivery. PMID:23662604

Jain, Ashish; Jain, Aviral; Gulbake, Arvind; Shilpi, Satish; Hurkat, Pooja; Jain, Sanjay K

2013-01-01

291

Mesocopic Structure of Nonviral Gene Delivery Vectors  

NASA Astrophysics Data System (ADS)

In general, little is known about nonviral gene delivery vector formation kinetics and the interplay between vector structure, especially mesoscopic structure, and transfection efficiency. DNA complexation with various condensing agents is a self-assembly process driven primarily by electrostatic interactions and counterion release. DNA complexation kinetics influence two physical parameters that directly affect gene delivery and expression efficiency: DNA complex geometric size and molar mass (density). In this study we demonstrate the utility of time resolved multiangle laser light scattering (TR-MALLS) for probing DNA complexation kinetics, determining DNA complex size and density in real time and monitoring nonviral vector stability in liquid formulations and serum. The condensing agents considered are poly-L-lysine, polyethylenimine and various cationic liposome formulations.

van Zanten, John; Hanes, Justin; Lai, Eva; Har-El, Yah-El

2003-03-01

292

Mucoadhesive drug delivery systems  

PubMed Central

Mucoadhesion is commonly defined as the adhesion between two materials, at least one of which is a mucosal surface. Over the past few decades, mucosal drug delivery has received a great deal of attention. Mucoadhesive dosage forms may be designed to enable prolonged retention at the site of application, providing a controlled rate of drug release for improved therapeutic outcome. Application of dosage forms to mucosal surfaces may be of benefit to drug molecules not amenable to the oral route, such as those that undergo acid degradation or extensive first-pass metabolism. The mucoadhesive ability of a dosage form is dependent upon a variety of factors, including the nature of the mucosal tissue and the physicochemical properties of the polymeric formulation. This review article aims to provide an overview of the various aspects of mucoadhesion, mucoadhesive materials, factors affecting mucoadhesion, evaluating methods, and finally various mucoadhesive drug delivery systems (buccal, nasal, ocular, gastro, vaginal, and rectal).

Shaikh, Rahamatullah; Raj Singh, Thakur Raghu; Garland, Martin James; Woolfson, A David; Donnelly, Ryan F.

2011-01-01

293

Learning materials delivery system  

US Patent & Trademark Office Database

A learning materials delivery system contains an instruction unit. The instruction unit has a number of instruction sets, and each instruction set corresponds to a lesson in the instruction unit on an instruction subject. Each instruction set bears indicia corresponding to the instruction subject and includes a first instruction document, a second instruction document, and optionally one or more resource documents. The documents include information relating to the instruction unit and the instruction sets.

2000-09-12

294

Transdermal Drug Delivery  

Microsoft Academic Search

\\u000a Transdermal drug delivery is a validated technology contributing significantly to global pharmaceutical care. Since 1980,\\u000a impressive growth in this field has been observed with many commercial successes; importantly, a new chemical entity was recently\\u000a developed and approved for transdermal administration without having first been given as an injectable or oral dosage form.\\u000a The progress achieved has been based on the

Richard H. Guy

295

[Breech presentation and delivery procedure].  

PubMed

This retrospective study analysed the way of completing a breech delivery. The period between 2002-2005 at GAK Sarajevo was observed. The number of deliveries in this period was 7017, and out of total there were 245 breech presentation cases, making up 3,49 % of total deliveries. T'Ihe goal was to examine breech presentations in pregnant women with at least 37 weeks of gestation, our testing group consisted of 123 patients which makes up half the total number of breech presentations. We also observed occurence of patological conditions in pregnancy (EPH gestosis, RVP, dysproportio, oligo i polihydramnion), mother's diseses history (ST post SC, ST post conisationem, uterine malformations, luxatio coxae, epilepsy), as well as mother's age and number of previous deliveries. Out of 123 pregnancies, 79 (64,22 %) were completed by SC, 43 (34,95 %) were vaginal - manually assisted: Bracht-Veit-Smellie 24 (55,8 %) and Muller-Veit-Smellie 18 (41,8 %). Out of total number of pregnant women observed, 73 (59,34 %) had first delivery, 41 (33,33 %) second delivery, 4 (3,5 %) had third delivery, 1 (0,81 %) had fourth delivery, 2 (1,62 %) fifth delivery, 1 (0,81 %) sixt delivery and 1 (0.81 %) seventh delivery. PMID:17297861

Izetbegovi?, Sebija

2006-01-01

296

Interactive information delivery system  

US Patent & Trademark Office Database

An information delivery system including a head end broadcasting a data stream of media objects, the head end being coupled to a broadcast television interface and at least one information service provider and including an encoder for encoding information in the media object is disclosed. The system may deliver and implement a programming guide delineating programming information available on the information delivery system in one or more media objects in the data stream in an encoded fashion by the encoder. A user terminal is coupled to the head-end and receives the media objects. The user terminal has an output and includes a decoder for the media objects. Also provided in one aspect is a user interface, at least partially stored in the user-terminal, which selects a user-defined subset of media objects for provision to the output of the user terminal. Further, an information navigation system for an information delivery system is provided. The navigation system functions with the electronic program guide and includes a user interface having a plurality of icon representations of various functions of the system, and including a broadcast television interface. The navigation system also includes a smart service navigator which interacts with the user interface and the electronic program guide to provide an output to the user.

1999-12-21

297

Nanovehicular Intracellular Delivery Systems  

PubMed Central

This article provides an overview of principles and barriers relevant to intracellular drug and gene transport, accumulation and retention (collectively called as drug delivery) by means of nanovehicles (NV). The aim is to deliver a cargo to a particular intracellular site, if possible, to exert a local action. Some of the principles discussed in this article apply to noncolloidal drugs that are not permeable to the plasma membrane or to the blood–brain barrier. NV are defined as a wide range of nanosized particles leading to colloidal objects which are capable of entering cells and tissues and delivering a cargo intracelullarly. Different localization and targeting means are discussed. Limited discussion on pharmacokinetics and pharmacodynamics is also presented. NVs are contrasted to micro-delivery and current nanotechnologies which are already in commercial use. Newer developments in NV technologies are outlined and future applications are stressed. We also briefly review the existing modeling tools and approaches to quantitatively describe the behavior of targeted NV within the vascular and tumor compartments, an area of particular importance. While we list “elementary” phenomena related to different level of complexity of delivery to cancer, we also stress importance of multi-scale modeling and bottom-up systems biology approach.

PROKOP, ALES; DAVIDSON, JEFFREY M.

2013-01-01

298

Height of shock formation in the solar corona inferred from observations of type II radio bursts and coronal mass ejections  

NASA Astrophysics Data System (ADS)

Employing coronagraphic and EUV observations close to the solar surface made by the Solar Terrestrial Relations Observatory (STEREO) mission, we determined the heliocentric distance of coronal mass ejections (CMEs) at the starting time of associated metric type II bursts. We used the wave diameter and leading edge methods and measured the CME heights for a set of 32 metric type II bursts from solar cycle 24. We minimized the projection effects by making the measurements from a view that is roughly orthogonal to the direction of the ejection. We also chose image frames close to the onset times of the type II bursts, so no extrapolation was necessary. We found that the CMEs were located in the heliocentric distance range from 1.20 to 1.93 solar radii (Rs), with mean and median values of 1.43 and 1.38 Rs, respectively. We conclusively find that the shock formation can occur at heights substantially below 1.5 Rs. In a few cases, the CME height at type II onset was close to 2 Rs. In these cases, the starting frequency of the type II bursts was very low, in the range 25-40 MHz, which confirms that the shock can also form at larger heights. The starting frequencies of metric type II bursts have a weak correlation with the measured CME/shock heights and are consistent with the rapid decline of density with height in the inner corona.

Gopalswamy, N.; Xie, H.; Mäkelä, P.; Yashiro, S.; Akiyama, S.; Uddin, W.; Srivastava, A. K.; Joshi, N. C.; Chandra, R.; Manoharan, P. K.; Mahalakshmi, K.; Dwivedi, V. C.; Jain, R.; Awasthi, A. K.; Nitta, N. V.; Aschwanden, M. J.; Choudhary, D. P.

2013-06-01

299

Type II Radio Emission from Shock Formation In The Low Corona on 13-Jun-2010: Combined Observations from the ARTEMIS-IV Radiospectrograph and SDO/AIA  

NASA Astrophysics Data System (ADS)

High cadence observations in the low corona from AIA imagers combined with radiospectrograph high-resolution recordings give a new perspective of shock formation in the low corona. Using ARTEMIS-IV observations of drifting type-II metric radio emission and ultra-high resolution observations from the AIA imagers we present direct observation of shock formation in the EUV and its association to the accompanying type-II during the 13-Jun-2010 Event. We will show that, in this case, the coronal expansion driven by the formation of the CME ejecta is responsible for both EUV and radio emissions.

Kouloumvakos, A.; Vourlidas, A.; Preka-Papadema, P.; Hillaris, A.; Caroubalos, C.; Moussas, X.; Tsitsipis, P.; Kontogeorgos, A.

2012-01-01

300

Liposome formation from bile salt-lipid micelles in the digestion and drug delivery model FaSSIF(mod) estimated by combined time-resolved neutron and dynamic light scattering.  

PubMed

The flow of bile secretion into the human digestive system was simulated by the dilution of a bile salt-lipid micellar solution. The structural development upon the dilution of the fed state bile model FeSSIF(mod6.5) to the fasted state bile model FaSSIF(mod) was investigated by small-angle neutron scattering (SANS) and dynamic light scattering (DLS) in crossed beam experiments to observe small and large structures in a size range of 1 nm to 50 ?m in parallel. Because of the physiologically low lipid and surfactant concentrations of 2.625 mM egg-phosphatidylcholine and 10.5 mM taurocholate the sensitivity of the neutron-structural investigations was improved by partial solvent deuteration with 71% D(2)O, with control experiments in H(2)O. Static experiments of initial and end state systems after 6 days of development revealed the presence of mixed bile salt-lipid micelles of 5.1 nm size in the initial state model FeSSIF(mod6.5), and large liposomes in FaSSIF(mod), which represent the late status after dilution of bile secretion in the intestine in the fasted state. The liposomes depicted a size of 34.39 nm with a membrane thickness of 4.75 nm, which indicates medium to large size unilamellar vesicles. Crossed beam experiments with time-resolved neutron and light scattering experiments after fast mixing with a stopped-flow device revealed a stepwise structural dynamics upon dilution by a factor of 3.5. The liposome formation was almost complete five minutes after bile dilution. The liposomes 30 min after dilution resembled the liposomes found after 6 days and depicted a size of 44.56 nm. In the time regime between 3 and 100 s a kinetic intermediate was observed. In a further experiment the liposome formation was abolished when the dilution was conducted with a surfactant solution containing sodium dodecyl sulfate. PMID:21988605

Nawroth, Thomas; Buch, Philipp; Buch, Karl; Langguth, Peter; Schweins, Ralf

2011-11-16

301

Prospective of guar gum and its derivatives as controlled drug delivery systems  

Microsoft Academic Search

Guar gum is a non-ionic polysaccharide that is found abundantly in nature and has many properties desirable for drug delivery applications. However, due to its high swelling characteristics in aqueous solution, the use of guar gum as delivery carriers is limited. Guar gum can be modified by derivatization, grafting and network formation to improve its property profile for a wide

M. Prabaharan

2011-01-01

302

Reinventing multimedia delivery with MPEG-DASH  

NASA Astrophysics Data System (ADS)

This paper reviews the design concepts of the MPEG-DASH standard and how it can be employed for the delivery of live multimedia content over the Internet. MPEG-DASH is the MPEG's newest standard for streaming of multimedia content and is designed to leverage the extensive HTTP infrastructure that has evolved with the growth of the World Wide Web. The standard defines specifications for manifest and segment formats used between the content servers and the client devices. This paper focuses on the live streaming of video content, its challenges and how MPEG-DASH can be used for this application.

Sodagar, Iraj; Pyle, Harry

2011-09-01

303

The Role of Simulation Games: Supplement or Central Delivery Vehicle?  

ERIC Educational Resources Information Center

Reports the results of an experiment assessing the effectiveness of two different approaches to using simulation games in a marketing course. In one, the game was used as a supplement to the standard lecture/discussion format; in the other, it was used as the central delivery vehicle. Twenty-one references are listed. (Author/LLS)

Fritzsche, David J.

1980-01-01

304

Chronotherapeutic drug delivery.  

PubMed

Living organisms follow a circadian rhythm in which physiological processes such as hormonal secretion, metabolism, heart rate, and renal output are affected by the time of day. Chronotherapy coordinates drug delivery with the circadian rhythm to enhance effectiveness and mitigate adverse effects and is achieved by delivering a drug when the system is most susceptible. Cancer is a chronotherapeutic disorder. Cancer treatment requires high doses of intravenous medication to kill cancerous cells; however, normal cells are also killed, creating intolerable side effects. This review shows that chronotherapy can play a vital role in the quality of life and survival rate for oncology patients. PMID:22955155

Librodo, Paul; Buckley, Mitchell; Luk, Marilyn; Bisso, Andrea

305

Vacuum-Assisted Vaginal Delivery  

PubMed Central

Approximately 5% (1 in 20) of all deliveries in the United States are operative vaginal deliveries. The past 20 years have seen a progressive shift away from the use of forceps in favor of the vacuum extractor as the instrument of choice. This article reviews in detail the indications, contraindications, patient selection criteria, choice of instrument, and technique for vacuum-assisted vaginal delivery. The use of vacuum extraction at the time of cesarean delivery will also be discussed. With vacuum extraction becoming increasingly popular, it is important that obstetric care providers are aware of the maternal and neonatal risks associated with such deliveries and of the options available to effect a safe and expedient delivery.

Ali, Unzila A; Norwitz, Errol R

2009-01-01

306

Suprachoroidal and Intrascleral Drug Delivery  

Microsoft Academic Search

\\u000a Local drug delivery to the eye minimizes systemic side effects and targets specific ocular tissue. In preclinical studies,\\u000a transscleral and suprachoroidal delivery appear to achieve therapeutic drug tissue levels that target specific tissues, such\\u000a as the choroid and macula. These routes allow minimally invasive sustained delivery of drugs to the ocular posterior segment\\u000a while minimizing systemic drug levels and the

Timothy W. Olsen; Brian C. Gilger

307

Polysaccharides for colon targeted drug delivery.  

PubMed

Colon targeted drug delivery has the potential to deliver bioactive agents for the treatment of a variety of colonic diseases and to deliver proteins and peptides to the colon for their systemic absorption. Various strategies, currently available to target the release of drugs to colon, include formation of prodrug, coating of pH-sensitive polymers, use of colon-specific biodegradable polymers, timed released systems, osmotic systems, and pressure controlled drug delivery systems. Among the different approaches to achieve targeted drug release to the colon, the use of polymers especially biodegradable by colonic bacteria holds great promise. Polysaccharidases are bacterial enzymes that are available in sufficient quantity to be exploited in colon targeting of drugs. Based on this approach, various polysaccharides have been investigated for colon-specific drug release. These polysaccharides include pectin, guar gum, amylose, inulin, dextran, chitosan, and chondroitin sulphate. This family of natural polymers has an appeal to drug delivery as it is comprised of polymers with a large number of derivatizable groups, a wide range of molecular weights, varying chemical compositions, and, for the most part, low toxicity and biodegradability yet high stability. The most favorable property of these materials is their approval as pharmaceutical excipients. PMID:15200012

Chourasia, M K; Jain, S K

308

MRI in ocular drug delivery  

PubMed Central

Conventional pharmacokinetic methods for studying ocular drug delivery are invasive and cannot be conveniently applied to humans. The advancement of MRI technology has provided new opportunities in ocular drug-delivery research. MRI provides a means to non-invasively and continuously monitor ocular drug-delivery systems with a contrast agent or compound labeled with a contrast agent. It is a useful technique in pharmacokinetic studies, evaluation of drug-delivery methods, and drug-delivery device testing. Although the current status of the technology presents some major challenges to pharmaceutical research using MRI, it has a lot of potential. In the past decade, MRI has been used to examine ocular drug delivery via the subconjunctival route, intravitreal injection, intrascleral injection to the suprachoroidal space, episcleral and intravitreal implants, periocular injections, and ocular iontophoresis. In this review, the advantages and limitations of MRI in the study of ocular drug delivery are discussed. Different MR contrast agents and MRI techniques for ocular drug-delivery research are compared. Ocular drug-delivery studies using MRI are reviewed.

Li, S. Kevin; Lizak, Martin J.; Jeong, Eun-Kee

2008-01-01

309

Photomechanical drug delivery  

NASA Astrophysics Data System (ADS)

Photomechanical waves (PW) are generated by Q-switched or mode-locked lasers. Ablation is a reliable method for generating PWs with consistent characteristics. Depending on the laser wavelength and target material, PWs with different parameters can be generated which allows the investigation of PWs with cells and tissue. PWs have been shown to permeabilize the stratum corneum (SC) in vivo and facilitate the transport of drugs into the skin. Once a drug has diffused into the dermis it can enter the vasculature, thus producing a systemic effect. Fluorescence microscopy of biopsies show that 40-kDa molecules can be delivered to a depth of > 300 micrometers into the viable skin of rats. Many important drugs such as insulin, and erythropoietin are smaller or comparable in size, making the PWs attractive for transdermal drug delivery. There are three possible pathways through the SC: Transappendageal via hair follicles or other appendages, transcellular through the corneocytes, and intercellular via the extracellular matrix. The intracellular route appears to be the most likely pathway of drug delivery through the SC.

Doukas, Apostolos G.; Lee, Shun

2000-05-01

310

Applying models of targeted drug delivery to gene delivery.  

PubMed

Gene delivery requires targeted delivery systems. Exploratory simulations using models of targeted drug delivery helps one assess the worthiness of such systems, and helps quantify the expected therapeutic benefits of the systems. The drug targeting index (DTI), a ratio of availabilities, is a measure of pharmacokinetic benefit of the delivery device, based on a combination of a physiologically-based pharmacokinetic model and a single pharmacodynamic Emaxmodel. Pharmacodynamic outcomes are quantified by the degree of separation between the dose-response and dose-toxicity curves (SRT). Simulations are undertaken to investigate the potential linkage of DTI and SRT, a pharmacodynamic outcome. A significant positive linear relationship is found between the DTI and SRT. The relationship can be translated into a minimum pharmacokinetic requirement that can be used to guide making decisions regarding whether or not further pursue the development of a candidate gene-delivery device as a therapeutic agent. PMID:17271053

Lam, Tai Ning; Hunt, C Anthony

2004-01-01

311

Nanotechnology-based drug delivery systems  

Microsoft Academic Search

Nanoparticles hold tremendous potential as an effective drug delivery system. In this review we discussed recent developments in nanotechnology for drug delivery. To overcome the problems of gene and drug delivery, nanotechnology has gained interest in recent years. Nanosystems with different compositions and biological properties have been extensively investigated for drug and gene delivery applications. To achieve efficient drug delivery

Sarabjeet Singh Suri; Hicham Fenniri; Baljit Singh

2007-01-01

312

Vaginal Birth After Cesarean Delivery: Deciding on a Trial of Labor After a Cesarean Delivery (TOLAC)  

MedlinePLUS

What is a vaginal birth after cesarean delivery (VBAC)? If you have had a previous cesarean delivery , you have two choices ... vaginal birth after cesarean delivery (VBAC). What is a trial of labor after cesarean delivery (TOLAC)? A ...

313

Making Government Work: Electronic Delivery of Federal Services (Includes Summary).  

National Technical Information Service (NTIS)

Contents: Summary of Findings and Options; Information Technologies for Electronic Delivery; Telecommunications Infrastructure for Electronic Delivery; Electronic Benefits Transfer for Social Service Delivery; Grassroots Pertnering in Electronic Delivery;...

1993-01-01

314

Monitoring the tail current contribution to the Dcx index with NOAA/POES satellites: differences between CME and HSS driven storms  

NASA Astrophysics Data System (ADS)

It is well known that, in addition to the ring current, also other current systems like the magnetopause currents and the tail current have a significant contribution to the Dcx index. While the effect of the magnetopause currents are typically removed by correcting for the solar wind pressure, the effects of the tail current are less well understood and have received less attention. Still, some recent studies have shown that the tail current can have a significant and even a dominant contribution to the Dst index at least during the main phase of moderate storms. We have developed a semi-empirical model that expresses the Dcx index as a sum of ring current, tail current and magnetopause contributions. In the model, the tail current is monitored by observing the location of the night-side isotropic boundary of energetic protons using the MEPED energetic particle instrument onboard NOAA/POES satellites. We briefly present here the model paying particular attention to the tail current and the solar wind parameters driving it. We apply the model to a set of magnetic storms driven by coronal mass ejections (CME) and high speed solar wind streams (HSS), and discuss the differences in the tail and ring current response between these two drivers.

Asikainen, T.; Maliniemi, V.; Mursula, K.

2012-04-01

315

Isolation and promoter characterization of barley gene Itr1 encoding trypsin inhibitor BTI-CMe: differential activity in wild-type and mutant lys3a endosperm.  

PubMed

The gene Itr1, encoding trypsin inhibitor BTI-CMe, has been obtained from a genomic library of Hordeum vulgare L. The gene has no introns and presents in its 5'-upstream region 605 bp that are homologous to the long terminal repeats (LTR) of the 'copia-like' retro-transposon Bare-1. Functional analysis of the Itr1 promoter by transient expression in protoplasts derived from different barley tissues, has shown that in this system the Itr1 promoter retains its endosperm specifity and the trans-regulation mediated by the Lys3a gene. The proximal promoter extending 343 bp upstream of the translation initiation ATG codon is sufficient to confer full GUS expression and for endosperm specifity. In protoplasts derived from the lys3a mutant, Risø 1508, GUS activity was less than 5% of that obtained with the same constructs in the protoplasts of wild-type Bomi from which it derives. Gel retardation experiments, after incubation with proteins obtained from both types of endosperm nuclei, also show differential patterns. Possible reasons for these differences are discussed. PMID:8843947

Royo, J; Diaz, I; Rodriquez-Palenzuela, P; Carbonero, P

1996-08-01

316

The Different Behaviour of the Neutral Upper-Atmosphere in Periods Dominated by Corotating Currents and by CME-s Respectively  

NASA Astrophysics Data System (ADS)

The paper is based on total density data derived from the measurements of the CACTUS accelerometer from 1975 to 1979. The data were separated into two groups: the first (1975-1977) during solar minimum dominated by recurrent corotating streams originating from corona holes; the second (1977-1979) during rising solar activity dominated by coronal mass ejections (CME). Comparing the measurements with corresponding model data (CIRA'86) the following results have been obtained: 1/ the dependence of the residuals on Dst is steeper in the first than in the second period; 2/ the variance of the residuals is larger in the first than in the second period; 3/ there is a definite diurnal dependence of the residuals - the scatter being larger at night - in both cases, but it is stronger in the first period. We suppose that in the first period the larger variance is due to a stronger auroral electrojet in connection with recurrent streams and it launches stronger gravity waves. The hypothesis is supported by the results in our previous papers demonstrating - on the basis of measurements by the San Marco V satellite accelerometer - that sudden density variations like neutral density decreases or giant waves have also a maximum occurrence frequency at night.

Illés-Almár, E.; Almár, I.; Bencze, P.

317

Advising Models and Delivery Systems.  

ERIC Educational Resources Information Center

|Reviews factors influencing the organization and delivery of academic advising services. Discusses the strengths and weaknesses of seven two-year college organizational models, including faculty only, supplementary, split, dual, total intake, satellite, and self-contained models. Describes advising delivery systems using faculty advisors,…

King, Margaret C.

1993-01-01

318

Bioresponsive matrices in drug delivery  

Microsoft Academic Search

For years, the field of drug delivery has focused on (1) controlling the release of a therapeutic and (2) targeting the therapeutic to a specific cell type. These research endeavors have concentrated mainly on the development of new degradable polymers and molecule-labeled drug delivery vehicles. Recent interest in biomaterials that respond to their environment have opened new methods to trigger

Jin-Oh You; Dariela Almeda; George JC Ye; Debra T Auguste

2010-01-01

319

Transdermal drug delivery: Microfabrication insights  

Microsoft Academic Search

The paper presented an enhancement solution for transdermal drug delivery using microneedles array with biodegradable tips. The microneedles array was fabricated by using deep reactive ion etching (DRIE) and the biodegradable tips were made to be porous by electrochemical etching process. The porous silicon microneedle tips can greatly enhance the transdermal drug delivery in a minimum invasion, painless, and convenient

Ciprian Iliescu; Bangtao Chen; Jiashen Wei; Zhilian Yue

2009-01-01

320

PECTIN BASED DRUG DELIVERY SYSTEMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two drug delivery systems have been developed from pectin recently in our laboratory. (I) Pectin gel formulations for controlled fragrance release and (II) pectin/zein hydrogels for oral drug delivery. By altering the molecular characteristics or modifying the pectin hydrogel networks, the release ...

321

The Bankruptcy of Service Delivery.  

ERIC Educational Resources Information Center

The dominant concept of public education at present can be described as a "service delivery" model. The public wants its children educated, delegates the job to a government agency (the schools), and holds that agency responsible for the delivery of educational services. The problems in public education, however, will not be solved by holding the…

Seeley, David S.

322

Document Delivery: A Better Option?  

ERIC Educational Resources Information Center

Discusses the use of document delivery by academic and research libraries and lists 28 private document delivery services frequently cited in a survey of libraries who use the services. Topics addressed include traditional interlibrary loan services; the effects of rising journal costs, restricted budgets, and staff cuts; and copyright issues.…

Khalil, Mounir

1993-01-01

323

Operative vaginal delivery - Year 2000  

Microsoft Academic Search

Literature review was performed to analyze and define the current state of operative vaginal delivery. On the basis of published data, it is concluded that outlet and low forceps deliveries with ?45 degrees of rotation are effective and safe for both mother and baby. The greatest risk to mother or fetus occurs with operations performed at the 0 or +1

Gary D. V. Hankins; Thomas F. Rowe

1996-01-01

324

Chemical Abstracts' Document Delivery Service.  

ERIC Educational Resources Information Center

|The Document Delivery Service offered by Chemical Abstracts is described in terms of the DIALORDER option on the Dialog information retrieval system, mail requests, and requests transmitted through OCLC's Interlibrary Loan system. Transmission costs, success rates, delivery rates, and other considerations in utilizing the service are included.…

Rollins, Stephen

1984-01-01

325

Microneedles for transdermal drug delivery  

Microsoft Academic Search

The success of transdermal drug delivery has been severely limited by the inability of most drugs to enter the skin at therapeutically useful rates. Recently, the use of micron-scale needles in increasing skin permeability has been proposed and shown to dramatically increase transdermal delivery, especially for macromolecules. Using the tools of the microelectronics industry, microneedles have been fabricated with a

Mark R Prausnitz

2004-01-01

326

Novel Delivery Strategies for Glioblastoma  

PubMed Central

Brain tumors—particularly glioblastoma multiforme (GBM)—pose an important public health problem in the US. Despite surgical and medical advances, the prognosis for patients with malignant gliomas remains grim: current therapy for is insufficient with nearly universal recurrence. A major reason for this failure is the difficulty of delivering therapeutic agents to the brain: better delivery approaches are needed to improve treatment. In this article, we summarize recent progress in drug delivery to the brain, with an emphasis on convection-enhanced delivery of nanocarriers. We examine the potential of new delivery methods to permit novel drug- and gene-based therapies that target brain cancer stem cells (BCSCs) and discuss the use of nanomaterials for imaging of tumors and drug delivery.

Zhou, Jiangbing; Atsina, Kofi-Buaku; Himes, Benjamin T.; Strohbehn, Garth W.; Saltzman, W. Mark

2012-01-01

327

Transmucosal macromolecular drug delivery.  

PubMed

Mucosal surfaces are the most common and convenient routes for delivering drugs to the body. However, macromolecular drugs such as peptides and proteins are unable to overcome the mucosal barriers and/or are degraded before reaching the blood stream. Among the approaches explored so far in order to optimize the transport of these macromolecules across mucosal barriers, the use of nanoparticulate carriers represents a challenging but promising strategy. The present paper aims to compare the characteristics and potential of nanostructures based on the mucoadhesive polysaccharide chitosan (CS). These are CS nanoparticles, CS-coated oil nanodroplets (nanocapsules) and CS-coated lipid nanoparticles. The characteristics and behavior of CS nanoparticles and CS-coated lipid nanoparticles already reported [A. Vila, A. Sanchez, M. Tobio, P. Calvo, M.J. Alonso, Design of biodegradable particles for protein delivery, J. Control. Rel. 78 (2002) 15-24; R. Fernandez-Urrusuno, P. Calvo, C. Remunan-Lopez, J.L. Vila-Jato, M.J. Alonso, Enhancement of nasal absorption of insulin using chitosan nanoparticles, Pharm. Res. 16 (1999) 1576-1581; M. Garcia-Fuentes, D. Torres, M.J. Alonso, New surface-modified lipid nanoparticles as delivery vehicles for salmon calcitonin (submitted for publication).] are compared with those of CS nanocapsules originally reported here. The three types of systems have a size in the nanometer range and a positive zeta potential that was attributed to the presence of CS on their surface. They showed an important capacity for the association of peptides such as insulin, salmon calcitonin and proteins, such as tetanus toxoid. Their mechanism of interaction with epithelia was investigated using the Caco-2 model cell line. The results showed that CS-coated systems caused a concentration-dependent reduction in the transepithelial resistance of the cell monolayer. Moreover, within the range of concentrations investigated, these systems were internalized in the monolayer in a concentration-dependent manner. This uptake was slightly enhanced by the presence of the CS coating but, as compared with previously published results [M. Garcia-Fuentes, C. Prego, D. Torres, M.J. Alonso, Triglyceride-chitosan nanostructures for oral calcitonin delivery: evaluation in the Caco-2 cell model and in vivo (submitted for publication)], highly dependent on the nature of the lipid core. Nevertheless, these differences in the uptake of the CS-coated systems (solid lipid core or oily core) by the Caco-2 cells did not have a consequence in the in vivo behaviour. Indeed, both CS-coated systems (nanocapsules and CS-coated nanoparticles) showed an important capacity to enhance the intestinal absorption of the model peptide, salmon calcitonin, as shown by the important and long-lasting decrease in the calcemia levels observed in rats. PMID:15588901

Prego, C; García, M; Torres, D; Alonso, M J

2005-01-01

328

Why new delivery systems?  

PubMed

Although anesthetists have accomplished a remarkable safety record with commercially available anesthetic machines, these results have been obtained in spite of machine design, which could best be described as a nonsystem. In cases involving severely compromised patients, surgical procedures that severely alter patient physiology, and untoward events during "routine" anesthesia, it is a tribute to the flexibility and resourcefulness of anesthetists that more incidents do not occur. Industry has long sought precision, reliability, automatic control, and human-factors engineering in nonmedical applications, such as aircraft cockpit design, word-processing stations, and manufacturing processes. The relentless accretion of more and more nonintegrated gadgets onto an antiquated technology has exceeded the boundaries of proper function. Neither the patient nor the anesthetist is being served well by failure to implement state-of-the-art technology in anesthesic delivery systems. Anesthesiologists and others who are vitally interested in the welfare of their patients must insist that development of radically new integrated modular systems proceed at full speed. Their checkbooks can speak as loudly as the facts; it is time the manufacturers are aware that deep concern will be translated into purchasing decisions. PMID:6692678

Calkins, J M

1984-01-01

329

Controlled Release of Simvastatin from Biomimetic ?-TCP Drug Delivery System  

PubMed Central

Simvastatin have been shown to induce bone formation and there is currently a urgent need to develop an appropriate delivery system to sustain the release of the drug to increase therapeutic efficacy whilst reducing side effects. In this study, a novel drug delivery system for simvastatin by means of hydrothermally converting marine exoskeletons to biocompatible beta-tricalcium phosphate was investigated. Furthermore, the release of simvastatin was controlled by the addition of an outer apatite coating layer. The samples were characterized by x-ray diffraction analysis, fourier transform infrared spectroscopy, scanning electron microscopy and mass spectroscopy confirming the conversion process. The in-vitro dissolution of key chemical compositional elements and the release of simvastatin were measured in simulated body fluid solution showing controlled release with reduction of approximately 25% compared with un-coated samples. This study shows the potential applications of marine structures as a drug delivery system for simvastatin.

Chou, Joshua; Ito, Tomoko; Bishop, David; Otsuka, Makoto; Ben-Nissan, Besim; Milthorpe, Bruce

2013-01-01

330

Controlled release of simvastatin from biomimetic ?-TCP drug delivery system.  

PubMed

Simvastatin have been shown to induce bone formation and there is currently a urgent need to develop an appropriate delivery system to sustain the release of the drug to increase therapeutic efficacy whilst reducing side effects. In this study, a novel drug delivery system for simvastatin by means of hydrothermally converting marine exoskeletons to biocompatible beta-tricalcium phosphate was investigated. Furthermore, the release of simvastatin was controlled by the addition of an outer apatite coating layer. The samples were characterized by x-ray diffraction analysis, fourier transform infrared spectroscopy, scanning electron microscopy and mass spectroscopy confirming the conversion process. The in-vitro dissolution of key chemical compositional elements and the release of simvastatin were measured in simulated body fluid solution showing controlled release with reduction of approximately 25% compared with un-coated samples. This study shows the potential applications of marine structures as a drug delivery system for simvastatin. PMID:23349949

Chou, Joshua; Ito, Tomoko; Bishop, David; Otsuka, Makoto; Ben-Nissan, Besim; Milthorpe, Bruce

2013-01-18

331

On the existence of two different mechanisms of coronal mass ejection formation  

NASA Astrophysics Data System (ADS)

Data from Mark 3 and 4, DPM (Mauna Loa Solar Observatory), and from spacecrafts place-SOHO (LASCO C2, EIT), STEREO (COR1, EUVI) were analyzed. It is demonstrated that the difference between the physical nature of the "impulsive" and the "gradual" CMEs is mainly represented by such parameters as the CME location, velocity and angular size at the moment the CME emerges. The "gradual" CMEs are formed in the corona at 0.1R0 ? h ? 0.7R0 above the limb of the Sun (R0 is the solar radius). They start moving, when their angular size is ? 15-65 degrees (in the heliocentric coordinate system) and their initial velocity V0 ? 0. A probable mechanism for their formation is the eruption of a coronal flux rope from the equilib-rium state. The formation of "impulsive" CMEs appears to begin under the photosphere of the Sun and may be related to ejection of floating magnetic tubes (flux ropes) from the convective zone. At the photospheric level, the radial velocities of such magnetic tubes exceed the local sound velocity and may reach hundreds km/s, while their angular sizes do not exceed ? (1-5)° . Possible ejection of magnetic tubes from the convective zone was theoretically demonstrated earlier.

Eselevich, Victor; Eselevich, Maxim

332

Bioresponsive matrices in drug delivery  

PubMed Central

For years, the field of drug delivery has focused on (1) controlling the release of a therapeutic and (2) targeting the therapeutic to a specific cell type. These research endeavors have concentrated mainly on the development of new degradable polymers and molecule-labeled drug delivery vehicles. Recent interest in biomaterials that respond to their environment have opened new methods to trigger the release of drugs and localize the therapeutic within a particular site. These novel biomaterials, usually termed "smart" or "intelligent", are able to deliver a therapeutic agent based on either environmental cues or a remote stimulus. Stimuli-responsive materials could potentially elicit a therapeutically effective dose without adverse side effects. Polymers responding to different stimuli, such as pH, light, temperature, ultrasound, magnetism, or biomolecules have been investigated as potential drug delivery vehicles. This review describes the most recent advances in "smart" drug delivery systems that respond to one or multiple stimuli.

2010-01-01

333

Drug delivery to the ear.  

PubMed

Drug delivery to the ear is used to treat conditions of the middle and inner ear such as acute and chronic otitis media, Ménière's disease, sensorineural hearing loss and tinnitus. Drugs used include antibiotics, antifungals, steroids, local anesthetics and neuroprotective agents. A literature review was conducted searching Medline (1966-2012), Embase (1988-2012), the Cochrane Library and Ovid (1966-2012), using search terms 'drug delivery', 'middle ear', 'inner ear' and 'transtympanic'. There are numerous methods of drug delivery to the middle ear, which can be categorized as topical, systemic (intravenous), transtympanic and via the Eustachian tube. Localized treatments to the ear have the advantages of targeted drug delivery allowing higher therapeutic doses and minimizing systemic side effects. The ideal scenario would be a carrier system that could cross the intact tympanic membrane loaded with drugs or biochemical agents for the treatment of middle and inner ear conditions. PMID:23323784

Hoskison, E; Daniel, M; Al-Zahid, S; Shakesheff, K M; Bayston, R; Birchall, J P

2013-01-01

334

Variable delivery, fixed displacement pump  

DOEpatents

A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

Sommars, Mark F. (Sparland, IL)

2001-01-01

335

Bioresponsive matrices in drug delivery.  

PubMed

For years, the field of drug delivery has focused on (1) controlling the release of a therapeutic and (2) targeting the therapeutic to a specific cell type. These research endeavors have concentrated mainly on the development of new degradable polymers and molecule-labeled drug delivery vehicles. Recent interest in biomaterials that respond to their environment have opened new methods to trigger the release of drugs and localize the therapeutic within a particular site. These novel biomaterials, usually termed "smart" or "intelligent", are able to deliver a therapeutic agent based on either environmental cues or a remote stimulus. Stimuli-responsive materials could potentially elicit a therapeutically effective dose without adverse side effects. Polymers responding to different stimuli, such as pH, light, temperature, ultrasound, magnetism, or biomolecules have been investigated as potential drug delivery vehicles. This review describes the most recent advances in "smart" drug delivery systems that respond to one or multiple stimuli. PMID:21114841

You, Jin-Oh; Almeda, Dariela; Ye, George Jc; Auguste, Debra T

2010-11-29

336

On the Occurrence of Energetic Storm Particle Events and Type II Radio Bursts in CME-driven Shocks  

NASA Astrophysics Data System (ADS)

We discuss correlations between energetic storm particle (ESP) events and type II radio emission associated with coronal mass ejection-driven shocks detected during 1996-2006. Shocks that could not be associated with any type II radio emission within metric-to-kilometric wavelength range were defined to be radio-quiet (RQ). All other shocks were defined to be radio-loud (RL). ESP events were identified from the 66 keV-50 MeV proton intensities measured by the Electron, Proton and Alpha Monitor (EPAM) instrument on the Advanced Composition Explorer (ACE) spacecraft and the Energetic and Relativistic Nuclei and Electron (ERNE) experiment on the Solar and Heliospheric Observatory (SOHO). Electron ESP events were identified in the 38-53 keV energy channel of EPAM. It is remarkable that a large fraction (32%) of RQ shocks produced a particle flux increase at energies above 1.8 MeV. On the other hand, only 52% of RL shocks produced ESP events. Electron ESP events were observed in 20% of RQ shocks and 39% of RL shocks. We also find that ESP events during RQ shocks are less intense than those associated with RL shocks. Among RQ shocks, those with an ESP event have slightly more eastern source longitudes (median longitude E07), whereas those without have more western longitudes (median longitude W03). This difference probably reflects the asymmetry in the relative size of ESP events between the eastern and western flanks of the shock. Our results indicate that type II emission is important for the occurrence of ESP events. RL shocks produce frequently ESP events, and the associated ESP events are also more intense than those observed during RQ shocks. The variability in the occurrence of ESP events and type II radio bursts is probably due to differences in the shock formation in the low corona and changes in the properties of the shocks as they propagate through interplanetary space, and the escape efficiency of accelerated particles from the shock front.

Makela, P. A.; Gopalswamy, N.; Akiyama, S.; Xie, H.; Yashiro, S.

2010-12-01

337

Cellulose esters in drug delivery  

Microsoft Academic Search

Cellulose esters have played a vital role in the development of modern drug delivery technology. They possess properties that\\u000a are not only well-suited to the needs of pharmaceutical applications, but that enable construction of drug delivery systems\\u000a that address critical patient needs. These properties include very low toxicity, endogenous and\\/or dietary decomposition products,\\u000a stability, high water permeability, high T\\u000a g,

Kevin J. Edgar

2007-01-01

338

Ultrasound in Labor and Delivery  

Microsoft Academic Search

Ultrasound may play an important role in the management of labor and delivery. Induction of labor is a common obstetric intervention, performed in about 20% of pregnancies. Pre-induction cervical length, measured by transvaginal sonography, has been shown to have a significant association with the induction-to-delivery interval and the risk for cesarean section. In the management of labor there is extensive

Francisca S. Molina; Kypros H. Nicolaides

2010-01-01

339

Home delivery: a valuable service.  

PubMed

A large proportion of ostomy patients throughout the UK are using a stoma delivery company to obtain their stoma products (the exact number of which is not known). Patients are usually set up on a delivery service before leaving the hospital, and the process continues until no longer required, and/or the patient opts to use his or her local chemist, the patient has a reversal of his or her stoma or the patient dies. PMID:24037333

Cronin, Elaine

2013-09-12

340

Matrices and Scaffolds for DNA Delivery in Tissue Engineering  

PubMed Central

Regenerative medicine aims to create functional tissue replacements, typically through creating a controlled environment that promotes and directs the differentiation of stem or progenitor cells, either endogenous or transplanted. Scaffolds serve a central role in many strategies by providing the means to control the local environment. Gene delivery from the scaffold represents a versatile approach to manipulating the local environment for directing cell function. Research at the interface of biomaterials, gene therapy, and drug delivery has identified several design parameters for the vector and the biomaterial scaffold that must be satisfied. Progress has been made towards achieving gene delivery within a tissue engineering scaffold, though the design principles for the materials and vectors that produce efficient delivery require further development. Nevertheless, these advances in obtaining transgene expression with the scaffold have created opportunities to develop greater control of either delivery or expression and to identify the best practices for promoting tissue formation. Strategies to achieve controlled localized expression within the tissue engineering scaffold will have broad application to the regeneration of many tissues, with great promise for clinical therapies.

De Laporte, Laura; Shea, Lonnie D.

2007-01-01

341

Polymeric micelles for multidrug delivery and combination therapy.  

PubMed

The use of conventional therapy based on a single therapeutic agent is not optimal to treat human diseases. The concept called "combination therapy", based on simultaneous administration of multiple therapeutics is recognized as a more efficient solution. Interestingly, this concept has been in use since ancient times in traditional herbal remedies with drug combinations, despite mechanisms of these therapeutics not fully comprehended by scientists. This idea has been recently re-enacted in modern scenarios with the introduction of polymeric micelles loaded with several drugs as multidrug nanocarriers. This Concept article presents current research and developments on the application of polymeric micelles for multidrug delivery and combination therapy. The principles of micelle formation, their structure, and the developments and concept of multidrug delivery are introduced, followed by discussion on recent advances of multidrug delivery concepts directed towards targeted drug delivery and cancer, gene, and RNA therapies. The advantages of various polymeric micelles designed for different applications, and new developments combined with diagnostics and imaging are elucidated. A compilation work from our group based on multidrug-loaded micelles as carriers in drug-releasing implants for local delivery systems based on titania nanotubes is summarized. Finally, an overview of recent developments and prospective outlook for future trends in this field is given. PMID:23943229

Aw, Moom Sinn; Kurian, Mima; Losic, Dusan

2013-08-13

342

Thiomers for oral delivery of hydrophilic macromolecular drugs.  

PubMed

In recent years thiolated polymers (thiomers) have appeared as a promising new tool in oral drug delivery. Thiomers are obtained by the immobilisation of thio-bearing ligands to mucoadhesive polymeric excipients. By the formation of disulfide bonds with mucus glycoproteins, the mucoadhesive properties of thiomers are up to 130-fold improved compared with the corresponding unmodified polymers. Owing to the formation of inter- and intramolecular disulfide bonds within the thiomer itself, matrix tablets and particulate delivery systems show strong cohesive properties, resulting in comparatively higher stability, prolonged disintegration times and a more controlled drug release. The permeation of hydrophilic macromolecular drugs through the gastrointestinal (GI) mucosa can be improved by the use of thiomers. Furthermore, some thiomers exhibit improved inhibitory properties towards GI peptidases. The efficacy of thiomers in oral drug delivery has been demonstrated by various in vivo studies. A pharmacological efficacy of 1%, for example, was achieved in rats by oral administration of calcitonin tablets comprising a thiomer. Furthermore, tablets comprising a thiomer and pegylated insulin resulted in a pharmacological efficacy of 7% after oral application to diabetic mice. Low-molecular-weight heparin embedded in thiolated polycarbophil led to an absolute bioavailability of > or = 20% after oral administration to rats. In these studies, formulations comprising the corresponding unmodified polymer had only a marginal or no effect. These results indicate drug carrier systems based on thiomers appear to be a promising tool for oral delivery of hydrophilic macromolecular drugs. PMID:16296722

Bernkop-Schnürch, Andreas; Hoffer, Martin H; Kafedjiiski, Krum

2004-11-01

343

Development of an implantable drug delivery catheter.  

PubMed

A microtextured, pillared drug delivery system has been designed and tested in rabbits. This model has allowed for the calculation of the mass transport rate indicating after a 4 week time period a pillar device's mass transport rate K1 [min-1] is K1p 1.54 x 10(-2) in contrast to the smooth control which is K1C .043 x 10(-2) and K1im IM which is 0.136 x 10(-2). As a result of these experiments, it is apparent a micropillared drug delivery system is an order magnitude faster than an intramuscular injection and is 30 times faster than the smooth control device. The etiology for this difference is related to close blood vessel proximity and minimal to no fibrous capsule formation with the micropillared implant. Finally, even after a 6-month implantation time, the pillared device has greater reproducibility regarding curve profile and there is no loss in magnitude or rate of mass transport, in contrast the smooth control devices in many instances resulted in complete occlusion with total loss of mass transport capabilities. PMID:1751157

Lewandowski, J J; Picha, G J; Nguyen, A J; Bressen, D

344

Transcutaneous immunization with Intercell's vaccine delivery system.  

PubMed

Transcutaneous immunization (TCI) has become an attractive alternate route of immunization due to increase understanding of the skin immune system and to recent technical innovations in skin patch delivery systems. Basic principles of TCI have been demonstrated in animal and human studies, covering a variety of bacterial, viral, and cancer diseases. At Intercell, we have advanced two major platforms of TCI: 1) a needle-free vaccine delivery patch (VDP) and 2) a vaccine enhancement patch (VEP). Simplified, the VDP contains an antigen with or without an adjuvant that is administered on the skin; while the VEP contains only the adjuvant and is used in combination with an injected vaccine. In many of our TCI studies, the VDP or VEP is routinely applied on pretreated skin, in which the stratum corneum has been partially removed by mild abrasion. Recently, we have achieved technical breakthroughs in formulating and stabilizing vaccines in a dry patch format. For instance, a microplate-based screening process has been implemented to rapidly identify excipients, singularly or in combination, to stabilize biological macromolecules in patch blend formulations. A second technical innovation is our nonwoven (patch) disc matrix-supported drying technology, which allows efficient drying of our patch formulation blend to produce dry stable dosage forms of VDP or VEP. The low cost and the facileness in the manufacturing of VDP (or VEP) combined with the development of thermostable dry patches should improve the supply chain efficiency and reduce the dependence on cold chain. PMID:22682290

Seid, Robert C; Look, Jee Loon; Ruiz, Christian; Frolov, Vladimir; Flyer, David; Schafer, Jason; Ellingsworth, Larry

2012-06-19

345

In situ forming polymeric drug delivery systems.  

PubMed

In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. PMID:20490289

Madan, M; Bajaj, A; Lewis, S; Udupa, N; Baig, J A

2009-05-01

346

Concept Formation.  

ERIC Educational Resources Information Center

This document, published in India by the Regional College of Education, deals with 13 subjects: the tough context (thinking), definitions of concept, functions of concept, the process of concept formation, discriminant learning, mediation process, second signalling system, factors affecting concept formation, studies in concept formation, the…

Vaidya, Narendera

347

Polyethylenimine–PEG coated albumin nanoparticles for BMP2 delivery  

Microsoft Academic Search

Bone Morphogenetic Protein-2 (BMP-2) plays an important role in stimulating new bone formation, and has been utilized in clinical bone repair by implantation. In this study, we report a nanoparticulate (NP) system for BMP-2 delivery based on bovine serum albumin (BSA) NPs stabilized with a poly(ethylene glycol) modified polyethylenimine (PEI–PEG) coating. PEI–PEG with different PEG substitutions were synthesized, and the

Sufeng Zhang; Cezary Kucharski; Michael R. Doschak; Walter Sebald; Hasan Uluda?

2010-01-01

348

Synthesis of the dimeric ? 2-O aminoalkoxy complexes of rhenium [(CO) 3Re(? 2-O ?NH 2)] 2 and their condensation products with acetone [(CO) 3Re(? 2-O ?N=CMe 2)] 2  

Microsoft Academic Search

The allyl rhenium complex Re(CO)4(?3-C3H5) (1) reacts with the amino alcohols 2-amino ethanol, 1-amino-propane-2-ol, 2-amino phenol and 2-amino benzyl alcohol (2a–d) to give the dimeric ?2-O-bridged tricyclic aminoalkoxy complexes of rhenium of the type [(CO)3Re(?2-O?NH2)]2 (3a–d). The acidic NH2 ligand undergoes a condensation reaction with acetone at r.t. forming the corresponding ketimine complexes [(CO)3Re(?2-O?N=CMe2)]2 (4a–d). The compounds have been characterized

R. Wilberger; H. Piotrowski; P. Mayer; I.-P. Lorenz

2002-01-01

349

Breech deliveries and cesarean section.  

PubMed

Breech presentation is the most common malpresentation, with about 3-4% of singleton fetuses presenting breech at delivery. Management of breech presentation has been a contentious issue with a lowering threshold for cesarean section in recent years. Perinatal mortality and morbidity are estimated to be three times that of comparable infants with vertex presentation. Breech presentation is commonly associated with certain adverse maternal and fetal factors which inherently give rise to increased perinatal morbidity and mortality. At present, most obstetricians favor cesarean delivery for uncomplicated pre-term breech. Controlled prospective studies have shown that the outcome of breech fetuses weighing more than 1500 g was not dependent on the mode of delivery. A more recent review from the Cochrane database by Grant does not justify a policy of elective cesarean section for pre-term breech. Vaginal delivery is preferred if the following criteria are met: frank breech only, estimated fetal weight of 2500-3500 g, adequate pelvimetry without hyperextended head, normal progression of labor, no evidence of fetal hypoxia under continuous fetal monitoring, and maternal weight under 90 kg. Vaginal delivery of frank breech at term may be just as safe as cesarean section when careful selection criteria are used. If these criteria are not fulfilled, or fetal monitoring cannot be performed, cesarean section is advisable. PMID:14601264

Papp, Zoltán

2003-01-01

350

Opening the Black Box: Exploring the Effect of Transformation on Online Service Delivery in Local Governments  

Microsoft Academic Search

To enhance the quality of their online service delivery, many government organizations seek to transform their organization\\u000a beyond merely setting up a front office. This transformation includes elements such as the formation of service delivery chains,\\u000a the adoption of a management strategy supporting process orientation and the implementation of enterprise architecture. This\\u000a paper explores whether undertaking this transformation has a

Anne Fleur Van Veenstra; Arre Zuurmond

2009-01-01

351

Developments in macromolecular drug delivery.  

PubMed

Macromolecular drugs hold great promise as novel therapeutics of several major disorders, such as cancer and cardiovascular disease. However, their use is limited by lack of efficient, safe, and specific delivery strategies. Successful development of such strategies requires interdisciplinary collaborations involving researchers with expertise on, e.g., polymer chemistry, cell biology, nanotechnology, systems biology, advanced imaging methods, and clinical medicine. This not only poses obvious challenges to the scientific community but also provides opportunities for the unexpected at the interface between different disciplines. This introductory chapter summarizes and gives references to studies on macromolecular delivery that should be of interest to a broad scientific audience involved in macromolecular drug synthesis as well as in vitro and in vivo drug delivery studies. PMID:19085127

Belting, Mattias; Wittrup, Anders

2009-01-01

352

Nanoparticulate systems for polynucleotide delivery  

PubMed Central

Nanotechnology has tremendously influenced gene therapy research in recent years. Nanometer-size systems have been extensively investigated for delivering genes at both local and systemic levels. These systems offer several advantages in terms of tissue penetrability, cellular uptake, systemic circulation, and cell targeting as compared to larger systems. They can protect the polynucleotide from a variety of degradative and destabilizing factors and enhance delivery efficiency to the cells. A variety of polymeric and non-polymeric nanoparticles have been investigated in an effort to maximize the delivery efficiency while minimizing the toxic effects. This article provides a review on the most commonly used nanoparticulate systems for gene delivery. We have discussed frequently used polymers, such as, polyethyleneimine, poly (lactide-co-glycolide), chitosan, as well as non-polymeric materials such as cationic lipids and metallic nanoparticles. The advantages and limitations of each system have been elaborated.

Basarkar, Ashwin; Singh, Jagdish

2007-01-01

353

From service delivery to application delivery in the telecommunication industry  

Microsoft Academic Search

Currently, in the Telecom industry all over the world the move towards service oriented infrastructures based on IP, IP Multimedia Subsystem (IMS), Service Oriented Architectures (SOA) and Service Delivery Platforms (SDP) can be observed and Communication Service Providers are opening parts of their core infrastructure and interfaces to third party developers. But there is a gap between application developer communities

Christian Menkens

2010-01-01

354

Functionalized organotin-chalcogenide complexes that exhibit defect heterocubane scaffolds: formation, synthesis, and characterization.  

PubMed

The synthesis of new functionalized organotin-chalcogenide complexes was achieved by systematic optimization of the reaction conditions. The structures of compounds [(R(1,?2) Sn)3 S4 Cl] (1, 2), [((R(2) Sn)2 SnS4 )2 (?-S)2 ] (3), [(R(1,?2) Sn)3 Se4 ][SnCl3 ] (4, 5), and [Li(thf)n ][(R(3) Sn)(HR(3) Sn)2 Se4 Cl] (6), in which R(1) =CMe2 CH2 C(O)Me, R(2) =CMe2 CH2 C(NNH2 )Me, and R(3) =CH2 CH2 COO, are based on defect heterocubane scaffolds, as shown by X-ray diffraction, (119) Sn?NMR spectroscopy, and ESI mass spectrometry analyses. Compounds 4, 5, and 6 constitute the first examples of defect heterocubane-type metal-chalcogenide complexes that are comprised of selenide ligands. Comprehensive DFT calculations prompted us to search for the formal intermediates [(R(1) SnCl2 )2 (?-S)] (7) and [(R(1) SnCl)2 (?-S)2 ] (8), which were isolated and helped to understand the stepwise formation of compounds 1-6. PMID:23963989

Eußner, Jens P; Barth, Beatrix E K; Leusmann, Eliza; You, Zhiliang; Rinn, Niklas; Dehnen, Stefanie

2013-08-21

355

Sun Emits a Solstice CME  

NASA Website

On June 20, 2013, at 11:24 p.m., the sun erupted with an Earth-directed coronal mass ejection, a solar phenomenon that can send billions of tons of particles into space that can reach Earth 1-3 days later.

356

Nanoparticulate material delivery to plants  

Microsoft Academic Search

The successful application of various nanoplatforms in medicine under in vitro conditions has generated some interest in agri-nanotechnology. This technology holds the promise of controlled release of agrochemicals and site targeted delivery of various macromolecules needed for improved plant disease resistance, efficient nutrient utilization and enhanced plant growth. Processes such as nanoencapsulation show the benefit of more efficient use and

Remya Nair; Saino Hanna Varghese; Baiju G. Nair; T. Maekawa; Y. Yoshida; D. Sakthi Kumar

2010-01-01

357

Drug delivery from jet nebulisers  

Microsoft Academic Search

Maximising the rate of drug delivered in particles small enough to reach the lower respiratory tract from jet nebulisers may allow treatment times to be reduced and thus improve the acceptability of this form of treatment, particularly in very young patients. The role of various technical factors such as driving gas flow (DGF) in determining the rate of drug delivery

M L Everard; A R Clark; A D Milner

1992-01-01

358

Career Information Delivery Systems Inventory.  

ERIC Educational Resources Information Center

|This inventory highlights similarities and differences between 19 computerized career information delivery systems (CIDS) so practitioners may make more informed choices concerning the adoption of such systems, and policymakers may monitor the developing scope of system features and costs. It was developed through a survey of computer products…

Olson, Gerald T.; Whitman, Patricia D.

359

Nanosuspension Technology for Drug Delivery  

Microsoft Academic Search

The poor water solubility of drugs is major problem for drug formulation. To date, nanoscale systems for drug delivery have gained much interest as a way to improve the solubility problems. The reduction of drug particles into the sub-micron range leads to a significant increase in the dissolution rate and therefore enhances bioavailability. Nanosuspensions are promising candidates that can be

Jiraporn CHINGUNPITUK

360

Gold nanoparticles in delivery applications  

Microsoft Academic Search

Gold nanoparticles (AuNPs) provide non-toxic carriers for drug and gene delivery applications. With these systems, the gold core imparts stability to the assembly, while the monolayer allows tuning of surface properties such as charge and hydrophobicity. An additional attractive feature of AuNPs is their interaction with thiols, providing an effective and selective means of controlled intracellular release.

Partha Ghosh; Gang Han; Mrinmoy De; Chae Kyu Kim; Vincent M. Rotello

2008-01-01

361

Regulated Antigen Delivery System (RADS).  

National Technical Information Service (NTIS)

We describe a regulated antigen delivery system (RADS) that has (a) a vector that includes (1) a gene encoding a desired gene product operably linked to a control sequence, (2) an origin of replication conferring vector replication using DNA polymerase II...

R. Curtis S. A. Tinge

2004-01-01

362

Hydrogel nanoparticles in drug delivery  

Microsoft Academic Search

Hydrogel nanoparticles have gained considerable attention in recent years as one of the most promising nanoparticulate drug delivery systems owing to their unique potentials via combining the characteristics of a hydrogel system (e.g., hydrophilicity and extremely high water content) with a nanoparticle (e.g., very small size). Several polymeric hydrogel nanoparticulate systems have been prepared and characterized in recent years, based

Mehrdad Hamidi; Amir Azadi; Pedram Rafiei

2008-01-01

363

Anesthesia Gas Delivery Systems Investigation.  

National Technical Information Service (NTIS)

The U.S. Food and Drug Administration (FDA) awarded the Texas Department of Health (TDH) a one-year contract to conduct a pilot project survey on anesthesia gas delivery systems in 17 hospitals and five freestanding surgical clinics in Texas. The faciliti...

1988-01-01

364

Multifunctional nanorods for gene delivery  

NASA Astrophysics Data System (ADS)

The goal of gene therapy is to introduce foreign genes into somatic cells to supplement defective genes or provide additional biological functions, and can be achieved using either viral or synthetic non-viral delivery systems. Compared with viral vectors, synthetic gene-delivery systems, such as liposomes and polymers, offer several advantages including ease of production and reduced risk of cytotoxicity and immunogenicity, but their use has been limited by the relatively low transfection efficiency. This problem mainly stems from the difficulty in controlling their properties at the nanoscale. Synthetic inorganic gene carriers have received limited attention in the gene-therapy community, the only notable example being gold nanoparticles with surface-immobilized DNA applied to intradermal genetic immunization by particle bombardment. Here we present a non-viral gene-delivery system based on multisegment bimetallic nanorods that can simultaneously bind compacted DNA plasmids and targeting ligands in a spatially defined manner. This approach allows precise control of composition, size and multifunctionality of the gene-delivery system. Transfection experiments performed in vitro and in vivo provide promising results that suggest potential in genetic vaccination applications.

Salem, Aliasger K.; Searson, Peter C.; Leong, Kam W.

2003-10-01

365

New Methods of Drug Delivery  

Microsoft Academic Search

Conventional forms of drug administration generally rely on pills, eye drops, ointments, and intravenous solutions. Recently, a number of novel drug delivery approaches have been developed. These approaches include drug modification by chemical means, drug entrapment in small vesicles that are injected into the bloodstream, and drug entrapment within pumps or polymeric materials that are placed in desired bodily compartments

Robert Langer

1990-01-01

366

Microneedles for transdermal drug delivery.  

PubMed

The success of transdermal drug delivery has been severely limited by the inability of most drugs to enter the skin at therapeutically useful rates. Recently, the use of micron-scale needles in increasing skin permeability has been proposed and shown to dramatically increase transdermal delivery, especially for macromolecules. Using the tools of the microelectronics industry, microneedles have been fabricated with a range of sizes, shapes and materials. Most drug delivery studies have emphasized solid microneedles, which have been shown to increase skin permeability to a broad range of molecules and nanoparticles in vitro. In vivo studies have demonstrated delivery of oligonucleotides, reduction of blood glucose level by insulin, and induction of immune responses from protein and DNA vaccines. For these studies, needle arrays have been used to pierce holes into skin to increase transport by diffusion or iontophoresis or as drug carriers that release drug into the skin from a microneedle surface coating. Hollow microneedles have also been developed and shown to microinject insulin to diabetic rats. To address practical applications of microneedles, the ratio of microneedle fracture force to skin insertion force (i.e. margin of safety) was found to be optimal for needles with small tip radius and large wall thickness. Microneedles inserted into the skin of human subjects were reported as painless. Together, these results suggest that microneedles represent a promising technology to deliver therapeutic compounds into the skin for a range of possible applications. PMID:15019747

Prausnitz, Mark R

2004-03-27

367

PREFERENCE FORMATION  

Microsoft Academic Search

? Abstract This review concerns political preferences—what they are and where they come from. We begin by documenting the close relationship between processes of preference formation and change. Rather than suddenly appearing, most preferences emerge from interactions between individuals and their environment. This aspect of preference formation poses a concrete challenge: to uncover the mechanics of these interactions in important

James N. Druckman; Arthur Lupia

2000-01-01

368

Formation fracturing  

Microsoft Academic Search

A fracturing process is described in which a fracture formed in a formation is acid etched near the well and particle propped in the more remote portions of the fracture. A fracture is formed in the formation extending from the well and an acidizing fluid is injected into the fracture, in order to acid etch the walls thereof adjacent to

J. L. Fitch; T. C. Jr. Vogt

1972-01-01

369

Star Formation During Galaxy Formation  

NASA Astrophysics Data System (ADS)

Young galaxies are clumpy, gas-rich, and highly turbulent. Star formation appears to occur by gravitational instabilities in galactic disks. The high dispersion makes the clumps massive and the disks thick. The star formation rate should be comparable to the gas accretion rate of the whole galaxy, because star formation is usually rapid and the gas would be depleted quickly otherwise. The empirical laws for star formation found locally hold at redshifts around 2, although the molecular gas consumption time appears to be smaller, and mergers appear to form stars with a slightly higher efficiency than the majority of disk galaxies.

Elmegreen, B. G.

2011-11-01

370

Waste feed delivery test and evaluation plan  

SciTech Connect

This plan documents the Waste Feed Delivery Program test and evaluation planning and implementation approach. The purpose of this document is to define and communicate the Waste Feed Delivery Program Test and Evaluation scope, objectives, planning and implementation approach.

O'TOOLE, S.M.

1999-09-30

371

Modes of delivery and delivery assistance in rural bangladesh.  

PubMed

Objectives: This paper employs statistical methods to identify the factors associated with modes of delivery and delivery assistance in rural areas of Bangladesh. The principal objective of this paper is to suggest various policy options on the basis of study findings in order to provide guidelines to improve the overall delivery-related morbidity conditions in Bangladesh. Methods: This study analyzes data from a followup study conducted by the Bangladesh Institute of Research for Health and Technologies (BIRPERHT) on maternal morbidity in rural Bangladesh in 1993. A total of 1020 pregnant women were interviewed in the followup component of the study. For the purpose of this study, we selected 993 pregnant women with at least one antenatal followup. Results: It is observed that the mode of delivery is complicated (assisted or destructive) if the pregnancy is either first or fifth or higher order and if bleeding occurred during the antenatal period. More educated respondents, high-risk pregnancies, pregnancies with past history of anemia and respondents who reported marriage at a relatively higher age receive assistance from trained personnel at a significantly higher proportion. Some of the important findings are: (1) first pregnancy or fifth or higher prior pregnancies and hemorrhage during pregnancy increase the risk of assisted or destructive modes of delivery; and (2) first or fifth or higher prior pregnancies are more likely to seek assistance from trained health personnel; similarly, regular antenatal visits and past history of anemia are also positively associated with seeking assistance from trained personnel. However, still there is a substantial proportion of women who remain at risk of complicated deliveries assisted by untrained personnel, posing a formidable challenge to policymakers. Conclusion: The results indicate several policy options: (1) the high-risk group, first or fifth or higher pregnancies, need special care and the existing health management system may be strengthened to create awareness among potential mothers for seeking appropriate measures from the beginning of pregnancy; (2) antenatal followup can be emphasized for high-risk pregnancies, and for respondents with a past history of anemia and other complications, a realistic referral system can be developed; (3) the campaign for increased age at marriage and increased age at first birth needs to focus the health issues more extensively; and (4) education for women needs to be given very high priority in order to bring about a lasting impact on the overall health condition of women. PMID:18272952

Islam, Ataharul; Rafiqul Islam, Chowdhury

2006-01-01

372

Outcomes of term vaginal breech delivery.  

PubMed

In December 2001, the American College of Obstetricians and Gynecologists revised their recommendations for breech delivery. These recommendations acknowledge that although a planned vaginal delivery may no longer be appropriate, there are instances in which vaginal breech delivery is inevitable. Moreover, there continues to be patients who for any number of reasons will choose vaginal over cesarean delivery when faced with a fetus in the breech presentation. We sought to review maternal and fetal outcomes in such circumstances when vaginal breech delivery occurs, and compare these outcomes to elective cesarean deliveries for breech presentation. We performed a retrospective review of all singleton breech deliveries at our county hospital from January 2002 through June 2003. We reviewed maternal age, ethnicity, gestational age, gravity, parity, birthweight, mode of delivery, Apgar scores, umbilical arterial blood gases, and maternal and infant complications of both cesarean deliveries and vaginal breech deliveries. Univariate and logistic regression statistical analyses were performed with NCSS software. We had a total of 150 term breech deliveries with gestational ages between 37 and 42 weeks. Of these, 41 were vaginal breech and 109 were cesarean deliveries. Greater than 95% of patients are of Hispanic origin. There were no statistically significant differences in maternal age, ethnicity, gravity, or gestational age. Mean birthweight was significantly lower and parity was significantly higher in the vaginal delivery group. There was also a higher proportion of patients who underwent labor induction/augmentation in the vaginal group. We found no differences in the outcomes of 5-minute Apgar scores, umbilical arterial blood gas values, neonatal intensive care unit admissions, deaths or maternal/fetal complications reported between the two groups. Mean umbilical arterial blood gas values were greater than 7.18 in both groups. Vaginal breech delivery cannot always be avoided. Moreover, at our county hospital several patients continue to choose vaginal breech delivery. Our data would suggest that vaginal breech delivery remains a viable option in selected patients. PMID:16118722

Doyle, Nora M; Riggs, John W; Ramin, Susan M; Sosa, Manuel A; Gilstrap, Larry C

2005-08-01

373

Chitosan-based gastrointestinal delivery systems  

Microsoft Academic Search

Chitosan, a natural polymer obtained by alkaline deacetylation of chitin, is non-toxic, biocompatible, and biodegradable. These properties make chitosan a good candidate for the development of conventional and novel gastrointestinal (GI) drug and gene delivery systems. The objective of this review is to summarize the recent applications of chitosan in oral and\\/or buccal delivery, stomach-specific drug delivery, intestinal delivery, and

Radi Hejazi; Mansoor Amiji

2003-01-01

374

Cyclodextrins in drug delivery: An updated review  

Microsoft Academic Search

The purpose of this review is to discuss and summarize some of the interesting findings and applications of cyclodextrins\\u000a (CDs) and their derivatives in different areas of drug delivery, particularly in protein and peptide drug delivery and gene\\u000a delivery. The article highlights important CD applications in the design of various novel delivery systems like liposomes,\\u000a microspheres, microcapsules, and nanoparticles. In

Rajeswari Challa; Alka Ahuja; Javed Ali; R. K. Khar

2005-01-01

375

Thiomers: potential excipients for non-invasive peptide delivery systems.  

PubMed

In recent years thiolated polymers or so-called thiomers have appeared as a promising alternative in the arena of non-invasive peptide delivery. Thiomers are generated by the immobilisation of thiol-bearing ligands to mucoadhesive polymeric excipients. By formation of disulfide bonds with mucus glycoproteins, the mucoadhesive properties of these polymers are improved up to 130-fold. Due to formation of inter- and intramolecular disulfide bonds within the thiomer itself, dosage forms such as tablets or microparticles display strong cohesive properties resulting in comparatively higher stability, prolonged disintegration times and a more controlled release of the embedded peptide drug. The permeation of peptide drugs through mucosa can be improved by the use of thiolated polymers. Additionally some thiomers exhibit improved inhibitory properties towards peptidases. The efficacy of thiomers in non-invasive peptide delivery could be demonstrated by various in vivo studies. Tablets comprising a thiomer and pegylated insulin, for instance, resulted in a pharmacological efficacy of 7% after oral application to diabetic mice. Furthermore, a pharmacological efficacy of 1.3% was achieved in rats by oral administration of calcitonin tablets comprising a thiomer. Human growth hormone in a thiomer-gel was applied nasally to rats and led to a bioavailability of 2.75%. In all these studies, formulations comprising the corresponding unmodified polymer had only a marginal or no effect. According to these results drug carrier systems based on thiomers seem to be a promising tool for non-invasive peptide drug delivery. PMID:15296953

Bernkop-Schnürch, Andreas; Krauland, Alexander H; Leitner, Verena M; Palmberger, Thomas

2004-09-01

376

Fiber Laser Coupled Optical Spark Delivery System.  

National Technical Information Service (NTIS)

A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to ...

A. Yalin B. Willson M. Defoort S. Joshi A. Reynolds

2005-01-01

377

Neonatal Outcomes After Elective Cesarean Delivery  

Microsoft Academic Search

OBJECTIVE: To examine the outcomes of neonates born by elective repeat cesarean delivery compared with vag- inal birth after cesarean (VBAC) in women with one prior cesarean delivery and to evaluate the cost differences between elective repeat cesarean and VBAC. METHODS: We conducted a retrospective cohort study of 672 women with one prior cesarean delivery and a singleton pregnancy at

Beena D. Kamath; James K. Todd; Judith E. Glazner; Dennis Lezotte; Anne M. Lynch

2009-01-01

378

Advancing the field of drug delivery  

Microsoft Academic Search

Drug delivery systems for cancer therapeutics have now been used by millions of patients and have resulted in the creation of new therapies as well as significantly improving existing ones. Here we discuss a number of the drug delivery systems that have been approved by regulatory authorities and that are currently in clinical use, such as controlled delivery of cancer

Marsha A Moses; Henry Brem; Robert Langer

2003-01-01

379

Biosensing and Drug Delivery at the Microscale  

Microsoft Academic Search

\\u000a The book chapter “Biosensing and Drug Delivery at the Microscale: Novel Devices for a Controlled and Responsive Drug Delivery”\\u000a published in the Handbook of Experimental Pharmacology vol. 197: Drug Delivery has been retracted. For further details see Erratum.

Andrea A. Robitzki; Randy Kurz

380

Magnetizable implants for targeted drug delivery  

Microsoft Academic Search

The capability to deliver high effective dosages to specific sites in the human body has become the holy grail of drug delivery research. Drugs with proven effectiveness under in vitro investigation often reach a major roadblock under in vivo testing due to a lack of an effective delivery strategy. In addition, many clinical scenarios require delivery of agents that are

Zachary Graham Forbes

2005-01-01

381

MEMS-based Implantable Drug Delivery System  

Microsoft Academic Search

Implantable devices are currently used regularly for chronic pain relief, cardiac pacemakers, arterial infusion for cancer and insulin delivery. A MEMS based implantable drug delivery system (IDDS) integrating a subcutaneous reservoir, an in plane silicon pump and associated circuitry for local or centralized delivery of therapeutic agents for chemotherapy is proposed. System configurations, flow rate analysis and applications are presented.

Smitha M. N. Rao; Amit Mhatre; Dan O. Popa; C. Chiao; Jeongsik Sin; Harry E. Stephanou

2005-01-01

382

Carboxymethyl starch and lecithin complex as matrix for targeted drug delivery: I. Monolithic Mesalamine forms for colon delivery.  

PubMed

For drugs expected to act locally in the colon, and for successful treatment, a delivery device is necessary, in order to limit the systemic absorption which decreases effectiveness and causes important side effects. Various delayed release systems are currently commercialized; most of them based on pH-dependent release which is sensitive to gastrointestinal pH variation. This study proposes a novel excipient for colon delivery. This new preparation consists in the complexation between carboxymethyl starch (CMS) and Lecithin (L). As opposed to existing excipients, the new complex is pH-independent, inexpensive, and easy to manufacture and allows a high drug loading. FTIR, X-ray, and SEM structural analysis all support the hypothesis of the formation of a complex. By minor variation of the excipient content within the tablet, it is possible to modulate the release time and delivery at specific sites of the gastrointestinal tract. This study opens the door to a new pH-independent delivery system for mesalamine targeted administration. Our novel formulation fits well with the posology of mesalamine, used in the treatment of Inflammatory Bowel Disease (IBD), which requires repeated administrations (1g orally four times a day) to maintain a good quality of life. PMID:23562535

Mihaela Friciu, Maria; Canh Le, Tien; Ispas-Szabo, Pompilia; Mateescu, Mircea Alexandru

2013-04-01

383

Cavitation-enhanced extravasation for drug delivery.  

PubMed

A flow-through tissue-mimicking phantom composed of a biocompatible hydro-gel with embedded tumour cells was used to assess and optimize the role of ultrasound-induced cavitation on the extravasation of a macromolecular compound from a channel mimicking vessel in the gel, namely a non-replicating luciferase-expressing adenovirus (Ad-Luc). Using a 500 KHz therapeutic ultrasound transducer confocally aligned with a focussed passive cavitation detector, different exposure conditions and burst mode timings were selected by performing time and frequency domain analysis of passively recorded acoustic emissions, in the absence and in the presence of ultrasound contrast agents acting as cavitation nuclei. In the presence of Sonovue, maximum ultraharmonic emissions were detected for peak rarefactional pressures of 360 kPa, and maximum broadband emissions occurred at 1250 kPa. The energy of the recorded acoustic emissions was used to optimise the pulse repetition frequency and duty cycle in order to maximize either ultraharmonic or broadband emissions while keeping the acoustic energy delivered to the focus constant. Cell viability measurements indicated that none of the insonation conditions investigated induces cell death in the absence of a therapeutic agent (i.e. virus). Phase contrast images of the tissue-mimicking phantom showed that short range vessel disruption can occur when ultra-harmonic emissions (nf0/2) are maximised whereas formation of a micro-channel perpendicular to the flow can be obtained in the presence of broadband acoustic emissions. Following Ad-Luc delivery, luciferase expression measurements showed that a 60-fold increase in its bioavailability can be achieved when broadband noise emissions are present during insonation, even for modest contrast agent concentrations. The findings of the present study suggest that drug delivery systems based on acoustic cavitation may help enhance the extravasation of anticancer agents, thus increasing their penetration distance to hypoxic regions and poorly vascularised tumour regions. PMID:21963037

Arvanitis, Costas D; Bazan-Peregrino, Miriam; Rifai, Bassel; Seymour, Leonard W; Coussios, Constantin C

2011-10-02

384

49 CFR 663.31 - Post-delivery audit requirements.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Post-delivery audit requirements. 663.31 Section 663...TRANSPORTATION PRE-AWARD AND POST-DELIVERY AUDITS OF ROLLING STOCK PURCHASES Post-Delivery Audits § 663.31 Post-delivery audit...

2011-10-01

385

[Pharmacokinetics of piracetam during delivery].  

PubMed

The excretion of Piracetam was monitored by measuring the concentrations in maternal and fetal substrates during labor in nine volunteers. Piracetam was tolerated without side-effects and injected in the maternal cubital vein. Consecutively, maternal plasma and urine samples as well as amniotic fluid portions were collected during labor. at delivery, fetal blood from placenta and the first fetal urines were collected. Biostatistical methods showed that approximately 50% of Piracetam were eliminated 80 minutes after the injection of the drug. In amniotic fluid a continuous rise of Piracetam concentrations was monitored until delivery. In fetal plasma and urines the substance could be detected. The rapid excretion of Piracetam during labor was obviously typical for the situation sub partu; reasons are discussed. PMID:700571

Cornely, M; Henkel, E; Trapp, H

1978-10-01

386

Thermoresponsive hydrogels for cellular delivery.  

PubMed

The delivery of living cells into a host body has emerged as a promising approach to treating a variety of different diseases and for tissue repair. However, one of the major obstacles for clinical success is to deliver the cells to the target tissue without losing control of cell fate and function after transplantation. Temperature-responsive biomaterials represent a promising vehicle to deliver cells noninvasively by injection of a liquid precursor, which undergoes a reversible phase transition at body temperature, thus, forming temperature-induced hydrogels in situ. The final material provides transplanted cells with a synthetic extracellular matrix, which retains the cells at the injection site, supports cell growth and mitigates migration. This mini review is intended to cover the fundamental physicochemical characteristics of these thermoresponsive biomaterials, and to examine the applications, with a focus on the recently developed cell-delivery systems for tissue engineering and cell therapy, including advantages, limitations and future challenges. PMID:23323558

Cellesi, Francesco

2012-12-01

387

Biodegradable microspheres in drug delivery.  

PubMed

General aspects of biodegradable microspheres prepared from natural and synthesized polymers used in drug delivery systems are reviewed first from various viewpoints: characteristics of biodegradable polymers (physicochemical properties, bioerosion mechanism, biocompatibility), preparation method for the microspheres, drug release from parenteral products and briefly nonparenteral products. The relationship between release pattern and pharmacological activity of therapeutic peptides and proteins and rational controlled release design are also discussed. In the latter half, successful sustained release depot formulations of peptides, leuprorelin acetate, and thyrotropin-releasing hormone (TRH), utilizing poly(lactic acid) (PLA) and poly(lactic/glycolic acid) (PLGA) microspheres are reviewed with respect to preparation, drug release, biocompatibility, pharmacological effects, and results of clinical studies. Thereafter, studies on antitumor therapy by chemoembolization using PLGA microspheres containing an angiogenesis inhibitor (TNP-470) are described as an example of targeted drug delivery with biodegradable microspheres. PMID:8521523

Okada, H; Toguchi, H

1995-01-01

388

The transdermal delivery of fentanyl.  

PubMed

The fentanyl patch is one of the great commercial successes in transdermal drug delivery. The suitability of this molecule for delivery through skin had been identified in the 1970s, and subsequently, a number of transdermal formulations became available on the market. This article reviews the development of fentanyl patch technology with particular emphasis on the pharmacokinetics and disposition of the drug when delivered through the skin. The various patch designs are considered as well as the bioequivalence of the different designs. The influence of heat on fentanyl permeation is highlighted. Post-mortem redistribution of fentanyl is discussed in light of the reported discrepancies in serum levels reported in patients after death compared with therapeutic levels in living subjects. Finally, alternatives to patch technology are considered, and recent novel transdermal formulations are highlighted. PMID:23419814

Lane, Majella E

2013-02-16

389

Gelatin Used for Drug Delivery  

NSDL National Science Digital Library

In this activity, learners discover how gelatin can be used as a medium for drug delivery. Learners create colored gelatin and then cut out pieces of the gelatin to simulate medicine (pills). Learners then put their simulated pills in a pan of hot water. Since gelatin is a thermoreversible or cold-setting polymer, gelatin will convert back to a liquid if put in a hot environment. As the gelatin returns to its liquid form, it releases its embedded dye. The dye eventually diffuses completely out of the gelatin which simulates the slow release of a drug from a pill. From this activity, learners learn more about diffusion and drug delivery. Adult supervision recommended.

Mississippi, University O.

2003-01-01

390

Hydrogen Production and Delivery Research  

Microsoft Academic Search

In response to DOE's Solicitation for Grant Applications DE-PS36-03GO93007, 'Hydrogen Production and Delivery Research', SRI International (SRI) proposed to conduct work under Technical Topic Area 5, Advanced Electrolysis Systems; Sub-Topic 5B, High-Temperature Steam Electrolysis. We proposed to develop a prototype of a modular industrial system for low-cost generation of H (<$2\\/kg) by steam electrolysis with anodic depolarization by CO. Water

Iouri Balachov

2007-01-01

391

Topical Delivery of Retinyl Ascorbate  

Microsoft Academic Search

This influence of skin stretching and hair follicle sealing on the delivery of retinyl ascorbate (RA-AsA) to the epidermis was probed in vitro. Porcine ear skin was subjected to stretching by 2 and 4 mm (3.3 and 6.7%, respectively); the hair follicles of other skin sections were located and painstakingly sealed using adhesive. After mounting in Franz cells the skin

Kasem Abdulmajed; Charles M. Heard

2008-01-01

392

CNS Delivery Via Adsorptive Transcytosis  

Microsoft Academic Search

Adsorptive-mediated transcytosis (AMT) provides a means for brain delivery of medicines across the blood-brain barrier (BBB).\\u000a The BBB is readily equipped for the AMT process: it provides both the potential for binding and uptake of cationic molecules\\u000a to the luminal surface of endothelial cells, and then for exocytosis at the abluminal surface. The transcytotic pathways present\\u000a at the BBB and

Françoise Hervé; Nicolae Ghinea; Jean-Michel Scherrmann

2008-01-01

393

Sediment delivery after a wildfire  

Microsoft Academic Search

We use a record of sedimentation in a small reservoir within the Cerro Grande burn area, New Mexico, to document postfire delivery of ash, other fine-grained sediment carried in suspension within floods, and coarse-grained sediment transported as bedload over a five-year period. Ash content of sediment layers is estimated using fallout 137Cs as a tracer, and ash concentrations are shown

Steven L. Reneau; Danny Katzman; Gregory A. Kuyumjian; Alexis Lavine; Daniel V. Malmon

2007-01-01

394

Biodegradable microspheres for parenteral delivery.  

PubMed

Nowadays, emphasis is being laid to development of controlled release dosage forms. Interest in this technology has increased steadily over the past few years. Although oral administration of drugs is a widely accepted route of drug delivery, bioavailability of drug often varies as a result of gastrointestinal absorption, degradation by first-pass effect, and hostile environment of gastrointestinal tract. Transdermal administration for percutaneous absorption of drug is limited by the impermeable nature of the stratum corneum. Ocular and nasal delivery is also unfavorable because of degradation by enzymes present in eye tissues and nasal mucosa. Hence, the parenteral route is the most viable approach in such cases. Of the various ways of achieving long-term parenteral drug delivery, biodegradable microspheres are one of the better means of controlling the release of drug over a long time. Because of the lipidic nature of liposomes, problems such as limited physical stability and difficulty of freeze-drying are encountered. Similarly, for emulsions, stability on long-term basis and in suspensions, rheological changes during filling, injecting, and storage poses limitation. Also, in all these systems, the release rate cannot be tailored to the needs of the patient. Parenteral controlled-release formulations based on biodegradable microspheres can overcome these problems and can control the release of drug over a predetermined time span, usually in the order of days to weeks to months. Various FDA-approved controlled-release parenteral formulations based on these biodegradable microspheres are available on the market, including Lupron Depot Nutropin Depot and Zoladex. This review covers various molecules encapsulated in biodegradable microspheres for parenteral delivery. PMID:16566705

Sinha, V R; Trehan, A

2005-01-01

395

Multiple pathways ensure retinoid delivery to milk: studies in genetically modified mice  

PubMed Central

Retinoids are absolutely required for normal growth and development during the postnatal period. We studied the delivery of retinoids to milk, availing of mouse models modified for proteins thought to be essential for this process. Milk retinyl esters were markedly altered in mice lacking the enzyme lecithin:retinol acyltransferase (Lrat?/?), indicating that this enzyme is normally responsible for the majority of retinyl esters incorporated into milk and not an acyl-CoA dependent enzyme, as proposed in the literature. Unlike wild-type milk, much of the retinoid in Lrat?/? milk is unesterified retinol, not retinyl ester. The composition of the residual retinyl ester present in Lrat?/? milk was altered from predominantly retinyl palmitate and stearate to retinyl oleate and medium chain retinyl esters. This was accompanied by increased palmitate and decreased oleate in Lrat?/? milk triglycerides. In other studies, we investigated the role of retinol-binding protein in retinoid delivery for milk formation. We found that Rbp?/? mice maintain milk retinoid concentrations similar to those in matched wild-type mice. This appears to arise due to greater postprandial delivery of retinoid, a lipoprotein lipase (LPL)-dependent pathway. Importantly, LPL also acts to assure delivery of long-chain fatty acids (LCFA) to milk. The fatty acid transporter CD36 also facilitated LCFA but not retinoid incorporation into milk. Our data show that compensatory pathways for the delivery of retinoids ensure their optimal delivery and that LRAT is the most important enzyme for milk retinyl ester formation.

Kako, Yuko; Deckelbaum, Richard J.; Hansen, Inge H.; Palczewski, Krzysztof; Goldberg, Ira J.; Blaner, William S.

2010-01-01

396

Physical non-viral gene delivery methods for tissue engineering.  

PubMed

The integration of gene therapy into tissue engineering to control differentiation and direct tissue formation is not a new concept; however, successful delivery of nucleic acids into primary cells, progenitor cells, and stem cells has proven exceptionally challenging. Viral vectors are generally highly effective at delivering nucleic acids to a variety of cell populations, both dividing and non-dividing, yet these viral vectors are marred by significant safety concerns. Non-viral vectors are preferred for gene therapy, despite lower transfection efficiencies, and possess many customizable attributes that are desirable for tissue engineering applications. However, there is no single non-viral gene delivery strategy that "fits-all" cell types and tissues. Thus, there is a compelling opportunity to examine different non-viral vectors, especially physical vectors, and compare their relative degrees of success. This review examines the advantages and disadvantages of physical non-viral methods (i.e., microinjection, ballistic gene delivery, electroporation, sonoporation, laser irradiation, magnetofection, and electric field-induced molecular vibration), with particular attention given to electroporation because of its versatility, with further special emphasis on Nucleofection™. In addition, attributes of cellular character that can be used to improve differentiation strategies are examined for tissue engineering applications. Ultimately, electroporation exhibits a high transfection efficiency in many cell types, which is highly desirable for tissue engineering applications, but electroporation and other physical non-viral gene delivery methods are still limited by poor cell viability. Overcoming the challenge of poor cell viability in highly efficient physical non-viral techniques is the key to using gene delivery to enhance tissue engineering applications. PMID:23099792

Mellott, Adam J; Forrest, M Laird; Detamore, Michael S

2012-10-26

397

Desflurane analgesia for vaginal delivery.  

PubMed

The use of subanaesthetic concentration of inhalational anaesthetic for vaginal delivery offers many advantages to the mother and newborn. Desflurane, with the characteristics of rapid onset and minimal metabolism, may provide better analgesia and safety for labour pain control. Eighty healthy parturients were randomly assigned to receive either desflurane 1.0-4.5% and oxygen (n = 40) or nitrous oxide 30-60% in oxygen (n = 40). Analgesia was assessed using a score from 0 (no relief) to 4+ (excellent analgesia), amnesia for the delivery, blood loss were recorded. Neonates were evaluated by Apgar scores and neurologic and adaptive capacity scores (NACS). Data were analyzed for statistical significance using Student's t-test or Chi-square when appropriate. Analgesia scores were similar for both groups with more amnesia in desflurane group (23% vs 0% P < 0.05). Blood loss did not differ significantly, 364 ml for the desflurane group and 335 ml for the nitrous oxide group. There were no significant differences for neonatal Apgar score at 1 min or at 5 min or the NACS at 2 hr or 24 hr between the two groups. We conclude that desflurane in subanaesthetic doses is safe and effective inhalation agent for normal delivery but might be associated with amnesia. PMID:7793195

Abboud, T K; Swart, F; Zhu, J; Donovan, M M; Peres Da Silva, E; Yakal, K

1995-02-01

398

The Sediment-delivery Fallacy  

NASA Astrophysics Data System (ADS)

The expression `sediment-delivery rate' was used by Glymph (1954) to denote the percentage relationship between annual sediment yield of a catchment and the annual gross erosion of the catchment. In subsequent literature, `sediment-delivery ratio' has been used. The latter is preferable. These ratios are typically less, often much less, than one. Both Boyce (1975) and Graf (1988) recognised that such ratios are problematic. They contravene Playfair's Law and mean that catchments must progressively fill with undelivered sedim ent. Both catchment sediment yield and gross erosion are measured in units of weight/area. These units are inappropriate for the data on which the ratios are based. Sediment yield is obtained either by measuring sedimentation in reservoirs or by sampling the sediment load carried in streamflow. These data are fluxes. There is no basis for assuming that the sediment flux at a point along a stream is proportional to the catchment area. Likewise, for hillslope erosion, it cannot be assumed that the flux of sediment measured at the outlet of an erosion plot has been derived from and is, therefore, proportional to the area of the plot. For both streams and hillslopes, data on travel distances of particles indicate that much of the sediment flux may be locally derived. The relationship of sediment flux to contributing area is both complex and dependent on the erosion processes. The sediment-delivery ratio is a fallacy born out of use of incorrect units of measurement.

Parsons, Anthony; Wainwright, John; Powell, Mark; Brazier, Richard

399

Physical methods to promote drug delivery on mucosal tissues of the oral cavity.  

PubMed

Introduction: The success of drug delivery through the mucosal tissue of the oral cavity represents a current challenge as well as a great future perspective. The need for more rapid onset of action and improved absorption of medications has resulted in great development of drug delivery technologies that use physical methods to overcome the barrier properties of oral mucosae. Areas covered: This review discusses the various physical techniques which have been, and are being, explored to sustain drug delivery in the oral cavity. In particular, supersaturation, eutectic formation, iontophoresis, electroporation, sonophoresis, laser radiation, photomechanical waves and needleless injection are considered. Following a careful selection of the most appropriate site and technique, in agreement with local variations of the oral mucosal permeability features, physical methods to promote drug delivery can improve treatment of diseases. Expert opinion: Although physical methods are very promising to promote drug delivery through keratinized epithelial tissues, they are not extensively used on the oral cavity mucosae. The authors feel that, in the near future, these methods could be further developed to provide noninvasive and convenient means for locoregional/systemic delivery of drugs with poor bioavailability profile, short half-life and multiple doses scheduling. This review will help the readers in the selection of a suitable physical method for improving drug delivery in the oral cavity for future chances. The authors imagine that new formulations or devices will be marketed in the coming years. PMID:23802558

Giannola, Libero Italo; Sutera, Flavia Maria; De Caro, Viviana

2013-06-27

400

Spatiotemporal delivery of bone morphogenetic protein enhances functional repair of segmental bone defects  

PubMed Central

Osteogenic growth factors that promote endogenous repair mechanisms hold considerable potential for repairing challenging bone defects. The local delivery of one such growth factor, bone morphogenetic protein (BMP), has been successfully translated to clinical practice for spinal fusion and bone fractures. However, improvements are needed in the spatial and temporal control of BMP delivery to avoid the currently used supraphysiologic doses and the concomitant adverse effects. We have recently introduced a hybrid protein delivery system comprised of two parts: a perforated nanofibrous mesh that spatially confines the defect region and a functionalized alginate hydrogel that provides temporal growth factor release kinetics. Using this unique spatiotemporal delivery system, we previously demonstrated BMP-mediated functional restoration of challenging 8 mm femoral defects in a rat model. In this study, we compared the efficacy of the hybrid system in repairing segmental bone defects to that of the current clinical standard, collagen sponge, at the same dose of recombinant human BMP-2. In addition, we investigated the specific role of the nanofibrous mesh tube on bone regeneration. Our results indicate that the hybrid delivery system significantly increased bone regeneration and improved biomechanical function compared to collagen sponge delivery. Furthermore, we observed that presence of the nanofiber mesh tube was essential to promote maximal mineralized matrix synthesis, prevent extra-anatomical mineralization, and guide an integrated pattern of bone formation. Together, these results suggest that spatiotemporal strategies for osteogenic protein delivery may enhance clinical outcomes by improving localized protein retention.

Kolambkar, Yash M.; Boerckel, Joel D.; Dupont, Kenneth M.; Bajin, Mehmet; Huebsch, Nathaniel; Mooney, David J.; Hutmacher, Dietmar W.; Guldberg, Robert E.

2011-01-01

401

Synthesis and characterization of diphenylglyoximato cobalt(III) complexes. The molecular structures of trans-bis(diphenylglyoximato)(alkyl)(pyridine)cobalt(III), with alkyl=CH 2SiMe 3, CH 2CMe 3 and CF 3  

Microsoft Academic Search

A series of Co(III) diphenylglyoximato (dpgh) complexes, pyCo(dpgh)2R, with R=Cl (2a), CH3 (3a), CH2Me (4a), (CH2)2Me (5a), (CH2)3Me (6a), CHMe2 (7a), CH2SiMe3 (8a), CH2CMe3 (9a), CH2CH?CH2 (10a), CH2Ph (11a), and CF3 (12a) were prepared, using Co(dpgh)(dpgh2)Cl2 (1a) as an entry to this system. The compounds were thoroughly characterized by 1H and 13C NMR spectroscopy, the spectra of which were compared

Paul J Toscano; Linda Lettko; E. James Schermerhorn; John Waechter; Kevin Shufon; Shuncheng Liu; Evgeny V Dikarev; Jon Zubieta

2003-01-01

402

Advances in Lymphatic Imaging and Drug Delivery  

SciTech Connect

Cancer remains the second leading cause of death after heart disease in the US. While metastasized cancers such as breast, prostate, and colon are incurable, before their distant spread, these diseases will have invaded the lymphatic system as a first step in their progression. Hence, proper evaluation of the disease state of the lymphatics which drain a tumor site is crucial to staging and the formation of a treatment plan. Current lymphatic imaging modalities with visible dyes and radionucleotide tracers offer limited sensitivity and poor resolution; however, newer tools using nanocarriers, quantum dots, and magnetic resonance imaging promise to vastly improve the staging of lymphatic spread without needless biopsies. Concurrent with the improvement of lymphatic imaging agents, has been the development of drug carriers that can localize chemotherapy to the lymphatic system, thus improving the treatment of localized disease while minimizing the exposure of healthy organs to cytotoxic drugs. This review will focus on polymeric systems that have been developed for imaging and drug delivery to the lymph system, how these new devices improve upon current technologies, and where further improvement is needed.

Nune, Satish K.; Gunda, Padmaja; Majeti, Bharat K.; Thallapally, Praveen K.; Laird, Forrest M.

2011-09-10

403

Gastrointestinal delivery of anti-inflammatory nanoparticles.  

PubMed

The concept of nanomedicine has risen to be the future of medicine. Advantages of using nanoobjects as vectors for drug delivery systems are numerous, such as fewer side effects due to a low drug dose, and high specificity between drug and target. Unlike systemic therapy, targeting a specific target is more efficient and less costly. In inflammatory bowel disease, including ulcerative colitis and Crohn disease, the colon represents the targeted organ. A large number of drugs are candidates for loading into nanoparticles (NPs). Small molecules, such as tripeptides and siRNA, or larger molecules, such as proteins (hormones, antibodies (Ab), etc.), can be encapsulated alone or in a complex form inside the NPs. In our studies, once NPs are synthesized and loaded with anti-inflammatory compounds, they are delivered to the colon. An efficient technique has been developed for specific NP targeting to digestive tract regions, including the colon, using a hydrogel based on electrostatic interactions between positive ions and negative polysaccharides. An in situ double cross-linking process, mediated by Ca²? and SO?²?, of chitosan and alginate administered to the mouse gastrointestinal (GI) tract by double gavage, is used for gel formation. When the drug is given in NPs, NPs are targeted to the colon, and NP degradation by aggressive environmental conditions in the GI tract is significantly reduced. Using a biomaterial (hydrogel) associated with nanotechnology, lower doses of drug can be loaded efficiently and delivered to the colon to reduce colonic inflammation. PMID:22568903

Laroui, Hamed; Sitaraman, Shanthi V; Merlin, Didier

2012-01-01

404

Local L-Arginine Delivery After Balloon Angioplasty Reduces Monocyte Binding and Induces Apoptosis  

Microsoft Academic Search

Background—Local administration of L-arginine after balloon angioplasty has been shown to enhance NO generation and inhibit lesion formation. In this study, we assessed the mechanisms by which local delivery of L-arginine inhibits lesion formation. Methods and Results—New Zealand White rabbits (n 556) were fed a 1% cholesterol diet. After 1 week, both iliac arteries were balloon-denuded, and a local drug

Josef Niebauer; Severin P. Schwarzacher; Motoya Hayase; Bingyin Wang; Robert S. Kernoff; John P. Cooke; Alan C. Yeung

1999-01-01

405

Localized drugs delivery hydroxyapatite microspheres for osteoporosis therapy  

NASA Astrophysics Data System (ADS)

This study describes the preparation of hydroxyapatite microspheres for local drugs delivery. The formation of the hydroxyapatite microspheres was initiated by enzymatic decomposition of urea and accomplished by emulsification process (water-in-oil). The microspheres obtained were sintered at 500°C. Scanning electron microscope (SEM) indicated that the microspheres have various porous with random size, which maximizes the surface area. Cytotoxicity was not observed after sintering. Osteoporosis drugs, alendronate and BMP-2, were loaded into HAp microspheres and the releases of both molecules showed sustained releasing profiles.

Lee, J. H.; Ko, I. H.; Jeon, S.-H.; Chae, J. H.; Lee, E. J.; Chang, J. H.

2011-09-01

406

Sediment delivery after a wildfire  

USGS Publications Warehouse

We use a record of sedimentation a small reservoir within the Cerro Grande burn area, New Mexico, to document postfire delivery of ash, other fine-grained sediment carried in suspension within floods, and coarse-grained sediment transported as bedload over a five-year period. Ash content of sediment layers is estimated using fallout 137Cs as a tracer, and ash concentrations are shown to rapidly decrease through a series of moderate-intensity convective storms in the first rainy season after the fire. Over 90% of the ash was delivered to the reservoir in the first year, and ash concentrations in suspended sediment were negligible after the second year. Delivery of the remainder of the fine sediment also declined rapidly after the first year despite the occurrence of higher-intensity storms in the second year. Fine sediment loads after five years remained significantly above prefire averages. Deposition of coarse-grained sediment was irregular in time and was associated with transport by snowmelt runoff of sediment stored along the upstream channel during short-duration summer floods. Coarse sediment delivery in the first four years was strongly correlated with snowmelt volume, suggesting a transport-limited system with abundant available sediment. Transport rates of coarse sediment declined in the fifth year, consistent with a transition to a more stable channel as the accessible sediment supply was depleted and the channel bed coarsened. Maximum impacts from ash and other fine-grained sediment therefore occurred soon after the fire, whereas the downstream impacts from coarse-grained sediment were attenuated by the more gradual process of bedload sediment transport. ?? 2007 Geological Society of America.

Reneau, S. L.; Katzman, D.; Kuyumjian, G. A.; Lavine, A.; Malmon, D. V.

2007-01-01

407

Sediment delivery after a wildfire  

NASA Astrophysics Data System (ADS)

We use a record of sedimentation in a small reservoir within the Cerro Grande burn area, New Mexico, to document postfire delivery of ash, other fine-grained sediment carried in suspension within floods, and coarse-grained sediment transported as bedload over a five-year period. Ash content of sediment layers is estimated using fallout 137Cs as a tracer, and ash concentrations are shown to rapidly decrease through a series of moderate-intensity convective storms in the first rainy season after the fire. Over 90% of the ash was delivered to the reservoir in the first year, and ash concentrations in suspended sediment were negligible after the second year. Delivery of the remainder of the fine sediment also declined rapidly after the first year despite the occurrence of higher-intensity storms in the second year. Fine sediment loads after five years remained significantly above prefire averages. Deposition of coarse-grained sediment was irregular in time and was associated with transport by snowmelt runoff of sediment stored along the upstream channel during short-duration summer floods. Coarse sediment delivery in the first four years was strongly correlated with snowmelt volume, suggesting a transport-limited system with abundant available sediment. Transport rates of coarse sediment declined in the fifth year, consistent with a transition to a more stable channel as the accessible sediment supply was depleted and the channel bed coarsened. Maximum impacts from ash and other fine-grained sediment therefore occurred soon after the fire, whereas the downstream impacts from coarse-grained sediment were attenuated by the more gradual process of bedload sediment transport.

Reneau, Steven L.; Katzman, Danny; Kuyumjian, Gregory A.; Lavine, Alexis; Malmon, Daniel V.

2007-02-01

408

Planet formation  

Microsoft Academic Search

Models of planetary formation are developed using the present single example of a planetary system, supplemented by limited astrophysical observations of star-forming regions and circumstellar disks. The solar nebula theory and the planetesimal hypothesis are discussed. The latter is found to provide a viable theory of the growth of the terrestrial planets, the cores of the giant planets, and the

Jack J. Lissauer

1993-01-01

409

Planet Formation  

NASA Astrophysics Data System (ADS)

1. Historical notes on planet formation Bodenheimer; 2. The formation and evolution of planetary systems Bouwman et al.; 3. Destruction of protoplanetary disks by photoevaporation Richling, Hollenbach and Yorke; 4. Turbulence in protoplanetary accretion disks Klahr, Rozyczka, Dziourkevitch, Wunsch and Johansen; 5. The origin of solids in the early solar system Trieloff and Palme; 6. Experiments on planetesimal formation Wurm and Blum; 7. Dust coagulation in protoplanetary disks Henning, Dullemond, Wolf and Dominik; 8. The accretion of giant planet cores Thommes and Duncan; 9. Planetary transits: direct vision of extrasolar planets Lecavelier des Etangs and Vidal-Madjar; 10. The core accretion - gas capture model Hubickyj; 11. Properties of exoplanets Marcy, Fischer, Butler and Vogt; 12. Giant planet formation: theories meet observations Boss; 13. From hot Jupiters to hot Neptures … and below Lovis, Mayor and Udry; 14. Disk-planet interaction and migration Masset and Kley; 15. The Brown Dwarf - planet relation Bate; 16. From astronomy to astrobiology Brandner; 17. Overview and prospective Lin.

Klahr, Hubert; Brandner, Wolfgang

2011-02-01

410

The synthesis of water soluble dendrimers, and their application as possible drug delivery systems  

Microsoft Academic Search

The synthesis of two water soluble dendrimers is described. The formation of water soluble inclusion complexes with a variety of small, hydrophobic guest molecules is also described. Moreover, when these guest molecules are drug moieties, then the resulting drug\\/dendrimer complexes can be considered ideal candidates for use as novel drug delivery systems.

Lance J. Twyman; Anthony E. Beezer; R. Esfand; Martin J. Hardy; John C. Mitchell

1999-01-01

411

A Blended Learning Lecture Delivery Model for Large and Diverse Undergraduate Cohorts  

ERIC Educational Resources Information Center

|A blended learning model was developed to enhance lecture delivery in a large, diverse introductory psychology unit, introducing the use of an online, personalized learning system for lecture preparation and using lecture time to extend students' understanding. Changes to the assessment included diagnostic, formative and summative online quizzes.…

McKenzie, Wendy A.; Perini, Eloise; Rohlf, Vanessa; Toukhsati, Samia; Conduit, Russell; Sanson, Gordon

2013-01-01

412

Convection-enhanced delivery of maghemite nanoparticles: Increased efficacy and MRI monitoring  

Microsoft Academic Search

Convection-enhanced drug delivery (CED) is a novel approach to delivering drugs into brain tissue. Drugs are delivered continuously via a catheter, enabling large volume distributions of high drug concentrations with minimum systemic toxicity. Previously we demonstrated that CED formation\\/extent of small molecules may be significantly improved by increasing infusate viscosities. In this study we show that the same methodology can

Benny Perlstein; Zvi Ram; Dianne Daniels; Aharon Ocherashvilli; Yiftach Roth; Shlomo Margel; Yael Mardor

413

Sustainability of Farm Credit Delivery by Cooperatives and NGOs in Edo and Delta States, Nigeria  

ERIC Educational Resources Information Center

The paper examined the sustainability rates of co-operatives and NGOs in farm credit delivery in Edo and Delta States of Nigeria. The Subsidy Dependence Indices (SDI) and the capital formation rates were determined using both primary and secondary data obtained from 80 and 20 purposively selected cooperatives and NGOs respectively, based on their…

Alufohai, G. O.

2006-01-01

414

Drug targeting to hypoxic tissue using self-inactivating bioreductive delivery systems  

Microsoft Academic Search

Hypoxia is a characteristic feature of a number of diseases including some cancers, rheumatoid arthritis and diabetes. Hypoxic tissue facilitates the use of bioreductive drug targeting systems as oxygen suppresses the release of the active drug. This review focuses on bioreductive delivery where accompanying intramolecular cyclisation negates adduct formation between the bioreductive and macromolecules such as DNA. To date, three

D. P Naughton

2001-01-01

415

Convection-Enhanced Drug Delivery: Increased Efficacy and Magnetic Resonance Image Monitoring  

Microsoft Academic Search

Convection-enhanced drug delivery (CED) is a novel approach to directly deliver drugs into brain tissue and brain tumors. It is based on delivering a continuous infusion of drugs via intracranial catheters, enabling convective distribution of high drug concentrations over large volumes of the target tissue while avoiding systemic toxicity. Efficient formation of convection depends on various physical and physiologic variables.

Yael Mardor; Ofer Rahav; Yacov Zauberman; Zvi Lidar; Aharon Ocherashvilli; Dianne Daniels; Yiftach Roth; Stephan E. Maier; Arie Orenstein

2005-01-01

416

Sustainability of Farm Credit Delivery by Cooperatives and NGOs in Edo and Delta States, Nigeria  

ERIC Educational Resources Information Center

|The paper examined the sustainability rates of co-operatives and NGOs in farm credit delivery in Edo and Delta States of Nigeria. The Subsidy Dependence Indices (SDI) and the capital formation rates were determined using both primary and secondary data obtained from 80 and 20 purposively selected cooperatives and NGOs respectively, based on their…

Alufohai, G. O.

2006-01-01

417

Writing MOT, reading AHA! : converting between an authoring and a delivery system for adaptive educational hypermedia  

Microsoft Academic Search

This paper reports about the recent advances towards establishing a common platform for adaptive educational hypermedia (AEH) authoring. We present the conversion from MOT, a dedicated authoring system, to A HA! used in this context as delivery system for AEH. Moreover, we describe two new representation languages that emerged in the process: a common format for defining the static material,

Alexandra Cristea; David Smits; PME De Bra

2005-01-01

418

Drug delivery by lipid cochleates.  

PubMed

Drug delivery technology has brought additional benefits to pharmaceuticals such as reduction in dosing frequency and side effects, as well as the extension of patient life. To address this need, cochleates, a precipitate obtained as a result of the interaction between phosphatidylserine and calcium, have been developed and proved to have potential in encapsulating and delivering small molecule drugs. This chapter discusses the molecules that can be encapsulated in a cochleate system and describes in detail the methodology that can be used to encapsulate and characterize hydrophobic drugs such as amphotericin B, a potent antifungal agent. Some efficacy data in animal models infected with candidiasis or aspergillosis are described as well. PMID:15721389

Zarif, Leila

2005-01-01

419

Physically facilitating drug-delivery systems  

PubMed Central

Facilitated/modulated drug-delivery systems have emerged as a possible solution for delivery of drugs of interest to pre-allocated sites at predetermined doses for predefined periods of time. Over the past decade, the use of different physical methods and mechanisms to mediate drug release and delivery has grown significantly. This emerging area of research has important implications for development of new therapeutic drugs for efficient treatments. This review aims to introduce and describe different modalities of physically facilitating drug-delivery systems that are currently in use for cancer and other diseases therapy. In particular, delivery methods based on ultrasound, electrical, magnetic and photo modulations are highlighted. Current uses and areas of improvement for these different physically facilitating drug-delivery systems are discussed. Furthermore, the main advantages and drawbacks of these technologies reviewed are compared. The review ends with a speculative viewpoint of how research is expected to evolve in the upcoming years.

Rodriguez-Devora, Jorge I; Ambure, Sunny; Shi, Zhi-Dong; Yuan, Yuyu; Sun, Wei; Xu, Tao

2012-01-01

420

Gene delivery by functional inorganic nanocarriers.  

PubMed

Gene delivery into cells to elicit cellular response has received a great attention recently. Viruses, lipids, peptides, cationic polymers and certain inorganic nanomaterials have been reported as gene delivery vectors. In this review, we focus on the recent literature on gene delivery using inorganic nanoparticles. This emerging field of study is concisely summarized and illustrated by selected examples and recent patents. New approaches and directions towards the practical use of multifunctional nanocarriers are highlighted. PMID:22670611

Loh, Xian Jun; Lee, Tung-Chun

2012-08-01

421

Microbially triggered drug delivery to the colon  

Microsoft Academic Search

Increasing acceptance of protein- and peptide-based drugs necessitates an investigation into the suitability of various sites for their administration. Colon is being investigated for delivery of such molecules. Colon-specific drug delivery is designed to target drug molecules specifically to this area. Development of site-specific delivery systems may exploit a specific property of the target site for drug activation\\/release. The gastrointestinal

V. R Sinha; Rachna Kumria

2003-01-01

422

Delivery of wheelchairs to disabled children.  

PubMed Central

In a follow-up study from a children's wheelchair clinic the delivery times for 120 wheelchairs ordered during 1973--7 were analysed. Delivery delays were considerable: only 22 of the 120 chairs were delivered within one month and 69 within three months, while 21 took over six months to arrive. Factors such as the type of chair ordered, the need for modifications, and the centre handling the transaction did not influence delivery time. Administrative delays may be an important contributory factor.

Dorsett, P; Holt, K S; Wisbeach, A

1978-01-01

423

Targeted Delivery Systems for Oligonucleotide Therapeutics  

Microsoft Academic Search

Oligonucleotides including antisense oligonucleotides and siRNA are emerging as promising therapeutic agents against a variety\\u000a of diseases. Effective delivery of these molecules is critical to their successful clinical application. Targeted systems\\u000a can greatly improve the efficiency and specificity of oligonucleotides delivery. Meanwhile, an effective delivery system must\\u000a successfully overcome a multitude of biological barriers to enable the oligonucleotides to reach

Bo Yu; Xiaobin Zhao; L. James Lee; Robert J. Lee

2009-01-01

424

Peptide-based hydrogel nanoparticles as effective drug delivery agents.  

PubMed

Peptide-based hydrogel nanoparticles represent a promising alternative to current drug delivery approaches. We have previously demonstrated that the Fmoc-FF aromatic dipeptide building block can self-assemble in aqueous solutions to form nano-scaled ordered hydrogels of remarkable mechanical rigidity. Here, we present a scalable process for the assembly of this peptide into hydrogel nanoparticles (HNPs) aimed to be utilized as potential drug delivery carriers. Fmoc-FF based HNPs were formulated via modified inverse-emulsion method using vitamin E-TPGS as an emulsion stabilizer and high speed homogenization. The formed HNPs exhibited two distinguishable populations with an average size of 21.5±1.3 and 225.9±0.8 nm. Gold nanoparticles were encapsulated within the hydrogel nanoparticles as contrast agents to monitor the formation of the assemblies and their ultrastructu