Note: This page contains sample records for the topic particle disease induced from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Oncornavirus particles in lymphoid cultures from a howler monkey with Herpesvirus saimiri-induced disease.  

PubMed

Budding and extracellular oncornavirus particles were observed in cells of lymphoid cultures derived from the spleen, lymph node, and blood of a howler monkey (Alouatta caraya) that developed a malignant lymphoproliferative disease after infection with Herpesvirus saimiri. The various possible sources of origin of these particles are discussed. PMID:187783

Rangan, S R

1976-10-01

2

Particles causing lung disease  

SciTech Connect

The lung has a limited number of patterns of reaction to inhaled particles. The disease observed depends upon the location: conducting airways, terminal bronchioles and alveoli, and upon the nature of inflammation induced: acute, subacute or chronic. Many different agents cause narrowing of conducting airways (asthma) and some of these cause permanent distortion or obliteration of airways as well. Terminal bronchioles appear to be particularly susceptible to particles which cause goblet cell metaplasia, mucous plugging and ultimately peribronchiolar fibrosis. Cancer is the last outcome at the bronchial level and appears to depend upon continuous exposure to or retention of an agent in the airway and failure of the affected cells to be exfoliated which may be due to squamous metaplasia. Alveoli are populated by endothelial cells, Type I or pavement epithelial cells and metabolically active cuboidal Type II cells that produce the lungs specific surfactant, dipalmytol lecithin. Disturbances of surfactant lead to edema in distal lung while laryngeal edema due to anaphylaxis or fumes may produce asphyxia. Physical retention of indigestible particles or retention by immune memory responses may provoke hyaline membranes, stimulate alveolar lipoproteinosis and finally fibrosis. This later exuberant deposition of connective tissue has been best studied in the occupational pneumoconioses especially silicosis and asbestosis. In contrast emphysema a catabolic response appears frequently to result from leakage or release of lysosomal proteases into the lung during processing of cigarette smoke particles. 164 references, 1 figure, 2 tables.

Kilburn, K.H.

1984-04-01

3

Particle accelerator for inducing contained particle collisions  

US Patent & Trademark Office Database

A particle accelerator for inducing contained particle collisions. The particle accelerator includes two hollow dees of electrically conductive material which are separated and electrically insulated from each other. The dees are located between the poles of a strong magnet which generates a magnetic field through top and bottom sides of the dees. In addition, the dees are connected to an oscillator for providing an alternating voltage between the dees. The dees are located within a chamber containing a gas and/or vapor provided at a measurable pressure. Ions are accelerated in essentially spiral paths within the dees, and follow paths which may be both concentric and non-concentric with the dees whereby collisions are produced between accelerated ions and gas or vapor atoms contained within the chamber, as well as between pairs of accelerated ions following different paths. The particle collisions within the chamber produces neutrons, generates energy, and performs other useful functions associated with the interaction of particles.

2002-08-27

4

[Gluten induced diseases].  

PubMed

The introduction of cereals in human nutrition 10 000 years ago caused the occurrence of gluten induced diseases. This protein complex is involved in pathogenesis of wheat allergy, celiac disease, and gluten sensitivity. Wheat allergy and celiac disease are mediated by the system of adaptive immunity. Gluten sensitivity is a recently defined entity induced by innate immune mechanisms. These subjects present various intestinal and particularly extraintestinal symptoms. The differences between celiac disease and gluten intolerance include permeability of the intestinal mucosal barrier, histology of duodenal biopsy, and mucosal gene expression. The symptoms of gluten sensitivity may also have another genetic background of food intolerance independent of the HLADQ2, -?DQ8 system and tissue transglutaminase (eg. in some psychiatric disorders). At present, there is no specific bio-marker of gluten sensitivity. The diagnosis is possible only by exclusion of other causes of symptoms and improvement on a glutenfree diet applied in a doubleblind placebo controlled manner with optional sequence of both stages to exclude the placebo effect due to nutritional intervention. PMID:23767452

Fri?, P; Zavoral, M; Dvo?áková, T

2013-05-01

5

Energetic-Particle-Induced Geodesic Acoustic Mode  

SciTech Connect

A new energetic particle-induced geodesic acoustic mode (EGAM) is shown to exist. The mode frequency and mode structure are determined nonperturbatively by energetic particle kinetic effects. In particular the EGAM frequency is found to be substantially lower than the standard GAM frequency. The radial mode width is determined by the energetic particle drift orbit width and can be fairly large for high energetic particle pressure and large safety factor. These results are consistent with the recent experimental observation of the beam-driven n=0 mode in DIII-D.

Fu, G. Y. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2008-10-31

6

The significance of nanoparticles in particle-induced pulmonary fibrosis  

PubMed Central

Exposure to airborne nanoparticles contributes to many chronic pulmonary diseases. Nanoparticles, classified as anthropogenic and natural particles, and fibers of diameters less than 100 nm, have unrestricted access to most areas of the lung due to their size. Size relates to the deposition efficiency of the particle, with particles in the nano-range having the highest efficiencies. The deposition of nanoparticles in the lung can lead to chronic inflammation, epithelial injury, and further to pulmonary fibrosis. Cases of particle-induced pulmonary fibrosis, namely pneumoconiosis, are mostly occupationally influenced, and continue to be documented around the world. The tremendous growth of nanotechnology, however, has spurred fears of increased rates of pulmonary diseases, especially fibrosis. The severity of toxicological consequences warrants further examination of the effects of nanoparticles in humans, possible treatments and increased regulatory measures.

Byrne, James D; Baugh, John A

2008-01-01

7

The significance of nanoparticles in particle-induced pulmonary fibrosis.  

PubMed

Exposure to airborne nanoparticles contributes to many chronic pulmonary diseases. Nanoparticles, classified as anthropogenic and natural particles, and fibers of diameters less than 100 nm, have unrestricted access to most areas of the lung due to their size. Size relates to the deposition efficiency of the particle, with particles in the nano-range having the highest efficiencies. The deposition of nanoparticles in the lung can lead to chronic inflammation, epithelial injury, and further to pulmonary fibrosis. Cases of particle-induced pulmonary fibrosis, namely pneumoconiosis, are mostly occupationally influenced, and continue to be documented around the world. The tremendous growth of nanotechnology, however, has spurred fears of increased rates of pulmonary diseases, especially fibrosis. The severity of toxicological consequences warrants further examination of the effects of nanoparticles in humans, possible treatments and increased regulatory measures. PMID:18523535

Byrne, James D; Baugh, John A

2008-01-01

8

Energetic Particle-induced Geodesic Acoustic Mode  

SciTech Connect

A new energetic particle-induced Geodesic Acoustic Mode (EGAM) is shown to exist. The mode frequency, mode structure, and mode destabilization are determined non-perturbatively by energetic particle kinetic effects. In particular the EGAM frequency is found to be substantially lower than the standard GAM frequency. The radial mode width is determined by the energetic particle drift orbit width and can be fairly large for high energetic particle pressure and large safety factor. These results are consistent with the recent experimental observation of the beam- driven n=0 mode in DIII-D. The new mode is important since it can degrade energetic particle confinement as shown in the DIII-D experiments. The new mode may also affect the thermal plasma confinement via its interaction with plasma micro-turbulence.

Fu, G.Y.

2008-09-12

9

Drug-induced liver disease.  

PubMed

Although the year 2001 did not see any prescription drugs withdrawn because of drug-induced liver disease, the US Food and Drug Administration requested that dietary supplements containing comfrey be taken off the market because of the danger of hepatic injury. The Food and Drug Administration remains very involved in the process by which drug-induced liver disease can be detected early in drug development and in the determination of how best to prevent hepatotoxicity after drug approval. A workshop on drug-induced liver disease cosponsored by the Food and Drug Administration, the Pharmaceutical Research and Manufacturers Association, and the American Association for the Study of Liver Diseases was held in Washington, DC, in February 2001, and the resulting white paper outlined several areas for research. A number of agents were newly described as causing various forms of liver injury, and several others had drug-induced liver disease confirmed by additional reports. Several investigators dealt with the difficulties inherent in establishing causality of drug-induced liver disease and the potential negative consequences of wrongly attributing hepatotoxicity to a particular agent. In one recent series, more than half the instances of alleged drug-induced liver disease were found to have other causes, often leading to a delay in the actual diagnosis and appropriate management. Case reports in particular were often misleading. Although several drug assessment scales have been developed, none appears to be foolproof. PMID:17033301

Lewis, James H

2002-05-01

10

Distinct inflammatory gene pathways induced by particles.  

PubMed

The biologic response to particulate load after arthroplasty has not been fully characterized but is believed mediated by proinflammatory cytokines released from mononuclear cells in the periprosthetic region. To investigate the contribution of lymphocytes to expression of proinflammatory genes induced by metal particles, we compared gene expression of mononuclear cells in response to metal and polymethylmethacrylate particles using cDNA microarray profiling. Peripheral blood mononuclear cells and monocytes were stimulated with polymethylmethacrylate and titanium particles of clinically relevant sizes. Polymethylmethacrylate elicited a six- to 12-fold increase in gene expression of tumor necrosis factor alpha, interleukin 1alpha, interleukin 1beta, interleukin 6, and interleukin 8 in purified monocytes and unfractionated peripheral blood mononuclear cells. Although the effect of titanium on stimulation of purified monocytes was modest, stimulation of lymphocyte-containing peripheral blood mononuclear cells by titanium particles resulted in monocyte-derived proinflammatory cytokine expression. In contrast to polymethylmethacrylate, titanium particles stimulated increased expression of T lymphocyte-derived cytokines, including interleukin 2, interferon gamma, interleukin 9, and interleukin 22, in peripheral blood mononuclear cell cultures. The induction of T cell activation by titanium particles suggests lymphocytes may contribute to the inflammation that mediates osteolysis in patients with metallic particulate debris after total joint replacement. PMID:17224841

Pearle, Andrew D; Crow, Mary K; Rakshit, Diptendu S; Wohlgemuth, Jay; Nestor, Bryan J

2007-05-01

11

Oestrogen deficiency modulates particle-induced osteolysis  

PubMed Central

Introduction Postmenopausal osteoporosis may modulate bone response to wear debris. In this article, we evaluate the influence of oestrogen deficiency on experimental particle-induced osteolysis. Methods Polyethylene (PE) particles were implanted onto the calvaria of normal controls, sham-ovariectomized (OVX), OVX mice and OVX mice supplemented with oestrogen (OVX+E). After 14 days, seven skulls per group were analyzed using a high-resolution micro-computed tomography (micro-CT) and histomorphometry, and for tartrate-specific alkaline phosphatase. Five calvariae per group were cultured for the assay of IL-1?, IL-6, TNF-? and receptor activator of the nuclear factor ?B (RANKL) secretion using quantitative ELISA. Serum IL-6 concentrations were obtained. The expression of RANKL and osteoprotegerin (OPG) mRNA were evaluated using real-time PCR. Results As assessed by ?CT and by histomorphometry, PE particles induced extensive bone resorption and an intense inflammatory reaction in normal controls, sham-OVX and OVX+E mice, but not in the OVX mice group. In normal controls, sham-OVX and OVX+E mice, PE particles induced an increase in serum IL-6, in TNF-? and RANKL local concentrations, and resulted in a significant increase in RANKL/OPG messenger RNA (mRNA) ratio. Conversely, these parameters remained unchanged in OVX mice after PE implantation. Conclusions Oestrogen privation in the osteolysis murine model ultimately attenuated osteolytic response to PE particles, suggesting a protective effect. This paradoxical phenomenon was associated with a down-regulation of pro-resorptive cytokines. It is hypothesized that excessive inflammatory response was controlled, illustrated by the absence of increase of serum IL-6 in OVX mice after PE implantation.

2011-01-01

12

Alpha-particle-induced cancer in humans.  

PubMed

Updated information is given on alpha-particle-induced cancer in persons internally exposed to 222Rn progeny, Thorotrast, long-lived 226Ra and 228Ra, and short-lived 224Ra. The lung cancer risk to persons breathing 222Rn progeny in the indoor air of offices, schools, and homes is of increasing concern. About half of the recent deaths among the German Thorotrast patients have been from liver cancer. Animal studies indicate that the liver cancer risk from Thorotrast is mainly from its radioactivity and that the risk coefficient for the Thorotrast patients can be used provisionally for other alpha emitters in the human liver. Six skeletal cancers have occurred in persons with average skeletal doses between 0.85 and 11.8 Gy from 226Ra and 228Ra. In the low-dose German 224Ra patients, two skeletal sarcomas have occurred at about 0.7 Gy compared to about six cases predicted by results from 224Ra patients at higher doses. The minimal appearance time for radiation-induced bone sarcomas in humans is about 4 y. Following brief irradiation, the vast majority of induced bone sarcomas are expressed by about 30 y. Recent evidence against the "practical threshold" hypothesis is given. With the downward revision of neutron doses to the atomic-bomb survivors, the follow-up of persons exposed to alpha particles may be the best opportunity to evaluate directly the effects of high LET radiation on humans. PMID:2844697

Mays, C W

1988-10-01

13

Drug Induced Interstitial Lung Disease  

PubMed Central

With an increasing number of therapeutic drugs, the list of drugs that is responsible for severe pulmonary disease also grows. Many drugs have been associated with pulmonary complications of various types, including interstitial inflammation and fibrosis, bronchospasm, pulmonary edema, and pleural effusions. Drug-induced interstitial lung disease (DILD) can be caused by chemotherapeutic agents, antibiotics, antiarrhythmic drugs, and immunosuppressive agents. There are no distinct physiologic, radiographic or pathologic patterns of DILD, and the diagnosis is usually made when a patient with interstitial lung disease (ILD) is exposed to a medication known to result in lung disease. Other causes of ILD must be excluded. Treatment is avoidance of further exposure and systemic corticosteroids in patients with progressive or disabling disease.

Schwaiblmair, Martin; Behr, Werner; Haeckel, Thomas; Markl, Bruno; Foerg, Wolfgang; Berghaus, Thomas

2012-01-01

14

Shear Induced diffusivity of non-spherical particles  

NASA Astrophysics Data System (ADS)

The shear induced diffusivity of non-spherical particles is studied both experimentally and numerically. Experimentally, the shear induced diffusivity of fractal aggregates is obtained by measuring the width of the interface between dyed and non-dyed suspensions flowing adjacently in a microfluidic channel using Leveque scaling. Numerical calculations of the shear induced diffusivity of rods, ``bucky balls'' and branched particles are performed by integrating the mean square displacement upon collision of two particles over all possible collisions. Particle trajectories are calculated using rigid body dynamics along with the Stokesian Dynamics method, and a short range repulsive force between beads belonging to different particles. The effect of the range of the repulsive force on the shear induced diffusivity is studied for all the particles used in our calculations. It is found that from the particles tested rods have the smallest shear induced diffusivity, while open branched particles have the largest. The increase in diffusivity is especially large in the vorticity direction.

Lopez, Mauricio

2005-11-01

15

Chromium-induced kidney disease  

SciTech Connect

Kidney disease is often cited as one of the adverse effects of chromium, yet chronic renal disease due to occupational or environmental exposure to chromium has not been reported. Occasional cases of acute tubular necrosis (ATN) following massive absorption of chromate have been described. Chromate-induced ATN has been extensively studied in experimental animals following parenteral administration of large doses of potassium chromate (hexavalent). The chromate is selectively accumulated in the convoluted proximal tubule where necrosis occurs. An adverse long-term effect of low-dose chromium exposure on the kidneys is suggested by reports of low molecular weight (LMW) proteinuria in chromium workers. Excessive urinary excretion of {beta}{sub 2}-microglobulin, a specific proximal tubule brush border protein, and retinol-binding protein has been reported among chrome palters and welders. However, LMW proteinuria occurs after a variety of physiologic stresses, is usually reversible, and cannot by itself be considered evidence of chromic renal disease. Chromate-induced ATN and LMW proteinuria in chromium workers, nevertheless, raise the possibility that low-level, long-term exposure may produce persistent renal injury. The absence of evidence of chromate-induced chromic renal disease cannot be interpreted as evidence of the absence of such injury.

Wedeen, R.P. (VA Medical Center, East Orange, NJ (United States)); Qian, Lifen (New Jersey Medical School, Newark (United States))

1991-05-01

16

Ultrafine particles from diesel engines induce vascular oxidative stress via JNK activation  

Microsoft Academic Search

Exposure to particulate air pollution is linked to increased incidences of cardiovascular diseases. Ambient ultrafine particles (UFP) from diesel vehicle engines have been shown to be proatherogenic in ApoE knockout mice and may constitute a major cardiovascular risk in humans. We posited that circulating nano-sized particles from traffic pollution sources induce vascular oxidative stress via JNK activation in endothelial cells.

Rongsong Li; Zhi Ning; Jeffery Cui; Bhavraj Khalsa; Lisong Ai; Wakako Takabe; Tyler Beebe; Rohit Majumdar; Constantinos Sioutas; Tzung Hsiai

2009-01-01

17

Mutations induced by heavy charged particles.  

PubMed

The relative biological-effectiveness of radiation is increased when cells or tissue are exposed to densely ionizing (high-LET) radiation. A large number of studies focus on the following aspects of the biological effects of high-LET radiation: (i) basic understanding of radiation damage and repair; (ii) developing radiotherapy protocols for accelerated charged particles; and (iii) estimation of human risks from exposure to high-LET heavy charged particles. The increased lethal effectiveness (cell inactivation) of high-LET radiation contributes to new methods for using radiation therapy, but it is also necessary to study the enhanced mutagenic effect of high LET radiation, because higher frequencies of mutation can be expected to provide higher rates of carcinogenicity with human exposure. It is important to note that both measures of biological effectiveness (lethality and mutagenicity) depend on the quality of radiation, the dose, dose-rate effects, and the biological endpoints studied. This paper is intended to provide a review of current research on the mutagenic effects of high-LET radiation, and is organized into three sections. First, are descriptions of the induced mutations studied with various detection systems (section 1) because the detectable mutations induced by ionizing radiation, including heavy-ions, depend largely on the detection system used. Second is a discussion of the biological significance of the dependence of induced mutations on LET (section 2). This is related to the molecular nature of radiation lesions and to the repair mechanisms used to help cells recover from such damage. Finally, applications of mutation detection systems for studies in space (section 3) are described, in which the carcinogenic effects of space environmental radiation are considered. PMID:15858389

Yatagai, Fumio

2004-12-01

18

Shear Induced diffusivity of non-spherical particles  

Microsoft Academic Search

The shear induced diffusivity of non-spherical particles is studied both experimentally and numerically. Experimentally, the shear induced diffusivity of fractal aggregates is obtained by measuring the width of the interface between dyed and non-dyed suspensions flowing adjacently in a microfluidic channel using Leveque scaling. Numerical calculations of the shear induced diffusivity of rods, ``bucky balls'' and branched particles are performed

Mauricio Lopez

2005-01-01

19

Alpha Particle Induced Reactions on Vanadium  

NASA Astrophysics Data System (ADS)

Alpha particle-induced reactions on the target element vanadium were investigated from threshold up to 55 MeV using the foil-stack activation technique and the Ge(Li) gamma ray spectroscopy method. Excitation functions for the formation of reaction residues 54Mn, 52Mn, 51Cr, 48V, 47Sc, 46Sc were investigated. The experimental cross-sections were compared with the predictions based on updated hybrid model (ALICE/90) using n0=4 (4p0h) and level density parameter a=A/9. A general agreement was found for all the reactions of (?, xn) type. However, the model failed badly in all cases of (?, z?xn) type of reactions.

Rao, A. V. Mohan; Chintalapudi, S. N.

20

Asbestos-induced lung disease.  

PubMed Central

This review attempts to deal with two major questions concerning asbestos-induced lung disease: How does inhaled asbestos cause cell proliferation and fibrosis? and Will there continue to be risk from exposure to asbestos in schools and public buildings? The first is a scientific question that has spawned many interesting new experiments over the past 10 years, and there appear to be two hypothetical schemes which could explain, at least in part, the fibroproliferative effects of asbestos fibers. One supports the view that toxic oxygen radicals generated on fiber surfaces and/or intracellularly are the central mediators of disease. The second hypothesis is not mutually exclusive of the first, but, in my opinion, may be integral to it, i.e., the cellular injury induced by oxygen radicals stimulates the elaboration of multiple varieties of growth factors and cytokines that mediate the pathogenesis of asbestosis. There is increasing evidence that molecules such as platelet-derived growth factor and transforming growth factor beta, both synthesized and secreted by activated lung macrophages, are responsible, respectively, for the increased interstitial cell populations and extracellular matrix proteins that are the hallmarks of asbestos-induced fibrosis. The challenge today is to establish which combinations of the many factors released actually are playing a role in disease pathogenesis. The issue of continued risk currently is more a question of policy and perception than science because a sufficient database has not yet been established to allow full knowledge of the circumstances under which asbestos in buildings constitutes an ongoing health hazard. The litigious nature of this question does not help its resolution. In as much as public policy statements and risk assessment are not within my purview, I have focused on the state-of-the-art of asbestos as a complete carcinogen. It appears to be generally nongenotoxic, but all asbestos fiber types can induce chromosomal mutations and aneuploidy, perhaps through their ability to disrupt normal chromosome segregation. Images FIGURE 1. 1a FIGURE 1. 1b FIGURE 2. FIGURE 3. FIGURE 4. 4a FIGURE 4. 4b FIGURE 5. 5a FIGURE 5. 5b FIGURE 6.

Brody, A R

1993-01-01

21

A human norovirus-like particle vaccine adjuvanted with ISCOM or mLT induces cytokine and antibody responses and protection to the homologous GII.4 human norovirus in a gnotobiotic pig disease model  

Microsoft Academic Search

We inoculated gnotobiotic pigs oraly\\/intranasally with human norovirus GII.4 HS66 strain virus-like particles (VLP) and immunostimulating complexes (ISCOM) or mutant E. coli LT toxin (mLT, R192G) as mucosal adjuvants, then assessed intestinal and systemic antibody and cytokine responses and homologous protection. Both vaccines induced high rates of seroconversion (100%) and coproconversion (75–100%). The VLP+mLT vaccine induced Th1\\/Th2 serum cytokines and

Menira Souza; Veronica Costantini; Marli. S. P. Azevedo; Linda. J. Saif

2007-01-01

22

Proposed definitions related to induced disease resistance  

Microsoft Academic Search

A clear definition of induced disease resistance is lacking, even though the area has been extensively researched and described. The lack of a precise definition leads to potential confusion on whether an underlying mechanism for biological control is induced resistance. We propose definitions, which were developed at a NATO Advanced Research Workshop on biological control, for induced disease resistance and

Joseph W. Kloepper; Sadik Tuzun; Joseph A. Ku?

1992-01-01

23

[Radiation-induced cardiac disease].  

PubMed

Radiation-induced effects may damage various cardiac structures chronically and cause heart valve dysfunction as well as occlusive lesions of coronary and other arteries exposed to radiation. A 72-year-old woman with a history of radiation treatment after breast cancer was admitted 25 years later with symptoms of tachycardia and acute dyspnea. We found valvular thickening, medium to severe valvular dysfunction and high grade occlusive coronary artery disease in proximal portions. The left subclavian artery also was affected. Surgical treatment was required immediately. Long-term follow-up cardiac evaluation even in asymptomatic patients is mandatory to uncover cardiac injuries by radiation. To lower the risk and maximize the benefit, early intervention by valvular replacement and myocardial revascularization is indicated. Restrictive myopathy and chronic pericarditis increase risk and have to be clarified. Diagnosis in these radiation exposed patients can be made by typical findings. Echocardiography is of eminent relevancy. PMID:14634766

Andresen, H; Kaag, N; Meinhardt, A; Potratz, J

2003-11-01

24

Alpha particle destabilization of the toroidicity-induced Alfven eigenmodes  

Microsoft Academic Search

The high frequency, low mode number toroidicity-induced Alfven eigenmodes (TAE) are shown to be driven unstable by the circulating and\\/or trapped α-particles through the wave-particle resonances. Satisfying the resonance condition requires that the α-particle birth speed v{sub α} ⥠v{sub A}\\/2{vert bar}m-nq{vert bar}, where v{sub A} is the Alfven speed, m is the poloidal model number, and n is the

1990-01-01

25

Novel laser induced interaction profiles in clusters of mesoscopic particles  

Microsoft Academic Search

We show that clusters of polarizable particles can form one or more equilibrium configurations in the presence of a laser field, with an equilibrium distance that depends sensitively on the frequency. The binding energy of these laser induced states scales with the particle volume and laser power making it possible to control by illumination the speed of agglomeration of weakly

F. Claro; R. Rojas

1994-01-01

26

Alpha particle destabilization of the toroidicity-induced Alfven eigenmodes.  

National Technical Information Service (NTIS)

The high frequency, low mode number toroidicity-induced Alfven eigenmodes (TAE) are shown to be driven unstable by the circulating and/or trapped (alpha)-particles through the wave-particle resonances. Satisfying the resonance condition requires that the ...

C. Z. Cheng

1990-01-01

27

Intrinsic particle-induced lateral transport in microchannels  

PubMed Central

In microfluidic systems at low Reynolds number, the flow field around a particle is assumed to maintain fore-aft symmetry, with fluid diverted by the presence of a particle, returning to its original streamline downstream. This current model considers particles as passive components of the system. However, we demonstrate that at finite Reynolds number, when inertia is taken into consideration, particles are not passive elements in the flow but significantly disturb and modify it. In response to the flow field, particles translate downstream while rotating. The combined effect of the flow of fluid around particles, particle rotation, channel confinement (i.e., particle dimensions approaching those of the channel), and finite fluid inertia creates a net recirculating flow perpendicular to the primary flow direction within straight channels that resembles the well-known Dean flow in curved channels. Significantly, the particle generating this flow remains laterally fixed as it translates downstream and only the fluid is laterally transferred. Therefore, as the particles remain inertially focused, operations can be performed around the particles in a way that is compatible with downstream assays such as flow cytometry. We apply this particle-induced transfer to perform fluid switching and mixing around rigid microparticles as well as deformable cells. This transport phenomenon, requiring only a simple channel geometry with no external forces to operate, offers a practical approach for fluid transfer at high flow rates with a wide range of applications, including sample preparation, flow reaction, and heat transfer.

Amini, Hamed; Sollier, Elodie; Weaver, Westbrook M.; Di Carlo, Dino

2012-01-01

28

Intrinsic particle-induced lateral transport in microchannels.  

PubMed

In microfluidic systems at low Reynolds number, the flow field around a particle is assumed to maintain fore-aft symmetry, with fluid diverted by the presence of a particle, returning to its original streamline downstream. This current model considers particles as passive components of the system. However, we demonstrate that at finite Reynolds number, when inertia is taken into consideration, particles are not passive elements in the flow but significantly disturb and modify it. In response to the flow field, particles translate downstream while rotating. The combined effect of the flow of fluid around particles, particle rotation, channel confinement (i.e., particle dimensions approaching those of the channel), and finite fluid inertia creates a net recirculating flow perpendicular to the primary flow direction within straight channels that resembles the well-known Dean flow in curved channels. Significantly, the particle generating this flow remains laterally fixed as it translates downstream and only the fluid is laterally transferred. Therefore, as the particles remain inertially focused, operations can be performed around the particles in a way that is compatible with downstream assays such as flow cytometry. We apply this particle-induced transfer to perform fluid switching and mixing around rigid microparticles as well as deformable cells. This transport phenomenon, requiring only a simple channel geometry with no external forces to operate, offers a practical approach for fluid transfer at high flow rates with a wide range of applications, including sample preparation, flow reaction, and heat transfer. PMID:22761309

Amini, Hamed; Sollier, Elodie; Weaver, Westbrook M; Di Carlo, Dino

2012-07-03

29

Particle-induced pitting corrosion of aluminum alloys  

NASA Astrophysics Data System (ADS)

Pitting corrosion has been identified as one of the principal precursors to fatigue crack initiation and growth in aluminum alloys. It has been attributed to the galvanic coupling between the constituent particles in the alloy and the surrounding matrix. To better understand particle induced pitting corrosion, the efforts of this dissertation research were directed toward fuller characterizations or the constituent particles, the morphology of corrosion pits, and the mechanism, processes, and kinetics of pitting. Model alloys were used to estimate their electrochemical properties and to develop information on the galvanic coupling between the alloy and constituent particles. In situ monitoring and pit replication techniques were developed to provide information on the processes of pitting corrosion in real-time and on the morphology of corrosion pits in three dimensions. Pitting is caused by the matrix dissolution due to the galvanic effect between particle-matrix coupling. Two pit morphology, general pits and severe pits, were induced due to the difference in particle distribution density. General pits are caused by individual particles and severe pits are induced by particle clusters at or beneath the surface. Corrosion of the particle-matrix couples is cathodically controlled and is governed by the particle size. Pit replica technique faithfully duplicated and reflected all of the key features of corrosion pits. This technique provides a 3-dimensional perspective and can aid in the quantitative assessments of the kinetics and the mechanistic understanding of pitting corrosion. A Conceptual Model was proposed to describe the mechanism of particle induced pitting. This model provides a new framework for understanding and modeling the nucleation and growth of corrosion pits in aluminum alloys. A Model for General Pitting has been established to describe the development of pitting at single particles in terms of the particle size and limiting cathodic current density over the particle. A simplified approach for modeling the growth of severe pits is described. Suggestions for further research are described, which include the development of mechanistic model that incorporates the potential and current distributions on the particle and the matrix, and methods for characterizing the spatial distribution of particles and clusters in aluminum alloys.

Liao, Chi-Min

30

Acoustically-Induced Birefringence in Rigid Particle Suspensions.  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. A suspension of rigid optically anisotropic particles can be made birefringent by applying an acoustic field to the medium, causing partial alignment of the particles. Transient changes in the birefringence are induced by the application of an acoustic pulse. The author has designed and constructed a unique apparatus whereby extremely highly intensity acoustic pulses, of MHz frequency, induce a significant birefringence in suspensions of synthetic polymers, metal oxides, clays and minerals. The transient birefringence is detected and analysed with a laser-based sensitive optical system and computerised signal analysis system. The measurements on the suspensions were made with a threefold purpose. First, to test two theories for acoustically induced birefringence (AIB) in suspensions. Second, to optically characterised the rigid particles in suspension, and third, to determine if such an apparatus could be used as a means of rapid particle sizing.

Honeywood, Mark Jason

31

Transient Flow Induced by the Adsorption of Particles  

NASA Astrophysics Data System (ADS)

When small particles, e.g., glass, flour, pollen, etc., come in contact with a fluid-liquid interface they disperse so quickly to form a monolayer on the interface that it appears explosive, especially on the surface of mobile liquids like water. This is a consequence of the fact that the adsorption of a particle in an interface causes a lateral flow which on the interface away from the particle. In this study we use the particle image velocimetry (PIV) technique to measure the transient three-dimensional flow that arises due to the adsorption of spherical particles. The PIV measurements show that the flow develops a fraction of a second after the adsorption of the particle and persists for several seconds. The fluid below the particle rises upwards and on the surface moves away from the particle. These latter PIV results are consistent with the surface velocity measurements performed in earlier studies. The strength of the induced flow, and the time duration for which the flow persists, both decrease with decreasing particle size. For a spherical particle the flow is axisymmetric about the vertical line passing through the center of the particle.

Musunuri, Naga; Codjoe, Daniel; Dalal, Bhavin; Fischer, Ian; Singh, Pushpendra

2013-03-01

32

Ripple induced trapped particle loss in tokamaks  

SciTech Connect

The threshold for stochastic transport of high energy trapped particles in a tokamak due to toroidal field ripple is calculated by explicit construction of primary resonances, and a numerical examination of the route to chaos. Critical field ripple amplitude is determined for loss. The expression is given in magnetic coordinates and makes no assumptions regarding shape or up-down symmetry. An algorithm is developed including the effects of prompt axisymmetric orbit loss, ripple trapping, convective banana flow, and stochastic ripple loss, which gives accurate ripple loss predictions for representative Tokamak Fusion Test Reactor and International Thermonuclear Experimental Reactor equilibria. The algorithm is extended to include the effects of collisions and drag, allowing rapid estimation of alpha particle loss in tokamaks.

White, R.B.

1996-05-01

33

Gyrokinetic particle simulation of beta-induced Alfven eigenmode  

SciTech Connect

The beta-induced Alfven eigenmode (BAE) in toroidal plasmas is studied using global gyrokinetic particle simulations. The BAE real frequency and damping rate measured in the initial perturbation simulation and in the antenna excitation simulation agree well with each other. The real frequency is slightly higher than the ideal magnetohydrodynamic (MHD) accumulation point frequency due to the kinetic effects of thermal ions. Simulations with energetic particle density gradient show exponential growth of BAE with a growth rate sensitive to the energetic particle temperature and density. The nonperturbative contributions by energetic particles modify the mode structure and reduce the frequency relative to the MHD theory. The finite Larmor radius effects of energetic particles reduce the BAE growth rate. Benchmarks between gyrokinetic particle simulation and hybrid MHD-gyrokinetic simulation show good agreement in BAE real frequency and mode structure.

Zhang, H. S. [Fusion Simulation Center and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697 (United States); Lin, Z.; Holod, I.; Xiao, Y. [Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697 (United States); Wang, X. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697 (United States); Zhang, W. L. [CAS Key Laboratory of Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697 (United States)

2010-11-15

34

Apoptosis induced by parasitic diseases  

Microsoft Academic Search

Fatalities caused by parasitic infections often occur as a result of tissue injury that results from a form of host-cell death known as apoptosis. However, instead of being pathogenic, parasite-induced apoptosis may facilitate host survival. Consequently, it is of utmost importance to decipher and understand the process and the role of apoptosis induced or controlled by parasites in humans. Despite

Anne-Lise Bienvenu; Elena Gonzalez-Rey; Stephane Picot

2010-01-01

35

Alpha particle destabilization of the toroidicity-induced Alfvén eigenmodes  

Microsoft Academic Search

The high-frequency, low mode number toroidicity-induced Alfven eigenmodes (TAE) (Phys. Fluids {bold 29}, 3695 (1986)) are shown to be driven unstable by the circulating and\\/or trapped α particles through the wave--particle resonances. Satisfying the resonance condition requires that the α-particle birth speed {ital v}{sub α}â¥{ital v}{sub A}\\/2{vert bar}{ital m}-{ital nq}{vert bar}, where {ital v}{sub A} is the Alfven speed, {ital

C. Z. Cheng

1991-01-01

36

Effect of Vaccination in Environmentally Induced Diseases  

Microsoft Academic Search

Along with the constant improvement in hygiene in the last few decades there has been a continuous increase in the incidence\\u000a of particular diseases, mainly of autoimmune or allergic etiology, but also of diseases caused by infectious agents, such\\u000a as listeriosis. We here present a model for the effect of exposure to agents causing or inducing the disease on the

Orit Lavi; Eyal Klement; Yoram Louzoun

2011-01-01

37

Infectious particles, stress, and induced prion amyloids  

PubMed Central

Transmissible encephalopathies (TSEs) are believed by many to arise by spontaneous conversion of host prion protein (PrP) into an infectious amyloid (PrP-res, PrPSc) without nucleic acid. Many TSE agents reside in the environment, with infection controlled by public health measures. These include the disappearance of kuru with the cessation of ritual cannibalism, the dramatic reduction of epidemic bovine encephalopathy (BSE) by removal of contaminated feed, and the lack of endemic scrapie in geographically isolated Australian sheep with susceptible PrP genotypes. While prion protein modeling has engendered an intense focus on common types of protein misfolding and amyloid formation in diverse organisms and diseases, the biological characteristics of infectious TSE agents, and their recognition by the host as foreign entities, raises several fundamental new directions for fruitful investigation such as: (1) unrecognized microbial agents in the environmental metagenome that may cause latent neurodegenerative disease, (2) the evolutionary social and protective functions of different amyloid proteins in diverse organisms from bacteria to mammals, and (3) amyloid formation as a beneficial innate immune response to stress (infectious and non-infectious). This innate process however, once initiated, can become unstoppable in accelerated neuronal aging.

2013-01-01

38

Particle-induced amorphization complex ceramic  

SciTech Connect

The presently funded three-year research program, supported by the Division of Materials Sciences of the Office of Basic Energy Sciences, was initiated on August 1, 1993; during the period in which the grant will have been active, $249,561 of support have been provided to date with an additional $79,723 to be spent during the third, final year (ending July 30, 1996). The primary purpose of the program is to develop an understanding of heavy-particle radiation effects -- {alpha}-recoil nuclei, fission fragments, ion-irradiations -- on ceramic materials and the thermal annealing mechanisms by which crystallinity might be restored. During the past two years, we have completed major studies on zircon (ZrSiO{sub 4}), olivine (Mg{sub 2}SiO{sub 4} and ten other compositions), spinel (MgAl{sub 2}O{sub 4} and four other compositions), and silica polymorphs (quartz, coesite and stishovite), as well as berlinite (AlPO{sub 4}) which is isomorphous with quartz. In addition, based on the above research, we propose the use of zircon as a host phase for the immobilization of plutonium resulting from weapons dismantlement.

Ewing, R.C.; Wang, Lu-Min

1996-02-16

39

Alpha particles induce apoptosis through the sphingomyelin pathway.  

PubMed

The sphingomyelin pathway involves the enzymatic cleavage of sphingomyelin to produce ceramide, a second messenger that serves as a key mediator in the rapid apoptotic response to various cell stressors. Low-linear energy transfer (LET) ? radiation can initiate this pathway, independent of DNA damage, via the cell membrane. Whether short-ranged, high-LET ? particles, which are of interest as potent environmental carcinogens, radiotherapies and potential components of dirty bombs, can act through this mechanism to signal apoptosis is unknown. Here we show that irradiation of Jurkat cells with ? particles emitted by the ²²?Ac-DOTA-anti-CD3 IgG antibody construct results in dose-dependent apoptosis. This apoptosis was significantly reduced by pretreating cells with cholesterol-depleting nystatin, a reagent known to inhibit ceramide signaling by interfering with membrane raft coalescence and ceramide-rich platform generation. The effects of nystatin on ?-particle-induced apoptosis were related to disruption of the ceramide pathway and not to microdosimetry alterations, because similar results were obtained after external irradiation of the cells with a broad beam of collimated ? particles using a planar ²?¹Am source. External irradiation allowed for more precise control of the dosimetry and geometry of the irradiation, independent of antibody binding or cell internalization kinetics. Mechanistically consistent with these findings, Jurkat cells rapidly increased membrane concentrations of ceramide after external irradiation with an average of five ?-particle traversals per cell. These data indicate that ? particles can activate the sphingomyelin pathway to induce apoptosis. PMID:21631289

Seideman, Jonathan H; Stancevic, Branka; Rotolo, Jimmy A; McDevitt, Michael R; Howell, Roger W; Kolesnick, Richard N; Scheinberg, David A

2011-06-01

40

Channel flow induced by wall injection of fluid and particles  

Microsoft Academic Search

The Taylor flow is the laminar single-phase flow induced by gas injection through porous walls, and is assumed to represent the flow inside solid propellant motors. Such a flow is intrinsically unstable, and the generated instabilities are probably responsible for the thrust oscillations observed in the aforesaid motors. However particles are embedded in the propellants usually used, and are released

Thierry Féraille; Grégoire Casalis

2003-01-01

41

Experimental particle acceleration by water evaporation induced by shock waves  

Microsoft Academic Search

Shock waves are commonly generated during volcanic eruptions. They induce sudden changes in pressure and temperature causing phase changes. Nevertheless, their effects on flowfield properties are not well understood. Here we investigate the role of gas expansion generated by shock wave propagation in the acceleration of ash particles. We used a shock tube facility consisting of a high-pressure (HP) steel

T. Scolamacchia; M. Alatorre Ibarguengoitia; B. Scheu; D. B. Dingwell; C. Cimarelli

2010-01-01

42

Analysis of charged particle induced reactions for beam monitor applications  

NASA Astrophysics Data System (ADS)

The reaction cross sections for different residual nuclides produced in the charged particle (p, d, 3He and ?) induced reactions were calculated and compared with the existing experimental data which are important for beam monitoring and medical diagnostic applications. A detailed literature compilation and comparison were made on the available data sets for the above reactions. These calculations were carried out using the statistical model code TALYS up to 100 MeV, which contains Kalbach's latest systematic for the emission of complex particles and complex particle-induced reactions. All optical model calculations were performed by ECIS-03, which is built into TALYS. The level density, optical model potential parameters were adjusted to get the better description of experimental data. Various pre-equilibrium models were used in the present calculations with default parameters.

Surendra Babu, K.; Lee, Young-Ouk; Mukherjee, S.

2012-07-01

43

Infectious bursal disease subviral particles displaying the foot-and-mouth disease virus major antigenic site.  

PubMed

An antigen delivery system based on subviral particles formed by the self-assembly of the capsid protein of infectious bursal disease virus and carrying foreign peptides at the top of the projection domain was investigated. We report here the effective insertion of the foot-and-mouth disease virus (FMDV) immunodominant epitope in one of the four external loops of the subviral particles. Out of the two loops tested, one of them tolerated an insert of 12 amino acids without disrupting the subviral particle assembly. The subviral particles reacted with neutralizing FMDV type O1 monoclonal and polyclonal antibodies and elicited a neutralizing antibody response in immunized mice. Furthermore, we found that they have the potential for the detection of FMDV antibodies in a competitive ELISA for diagnostic. PMID:18983883

Rémond, Michelle; Da Costa, Bruno; Riffault, Sabine; Parida, Satya; Breard, Emmanuel; Lebreton, Françoise; Zientara, Stephan; Delmas, Bernard

2008-11-05

44

Proteomic analysis of purified Newcastle disease virus particles  

PubMed Central

Background Newcastle disease virus (NDV) is an enveloped RNA virus, bearing severe economic losses to the poultry industry worldwide. Previous virion proteomic studies have shown that enveloped viruses carry multiple host cellular proteins both internally and externally during their life cycle. To address whether it also occurred during NDV infection, we performed a comprehensive proteomic analysis of highly purified NDV La Sota strain particles. Results In addition to five viral structural proteins, we detected thirty cellular proteins associated with purified NDV La Sota particles. The identified cellular proteins comprised several functional categories, including cytoskeleton proteins, annexins, molecular chaperones, chromatin modifying proteins, enzymes-binding proteins, calcium-binding proteins and signal transduction-associated proteins. Among these, three host proteins have not been previously reported in virions of other virus families, including two signal transduction-associated proteins (syntenin and Ras small GTPase) and one tumor-associated protein (tumor protein D52). The presence of five selected cellular proteins (i.e., ?-actin, tubulin, annexin A2, heat shock protein Hsp90 and ezrin) associated with the purified NDV particles was validated by Western blot or immunogold labeling assays. Conclusions The current study presented the first standard proteomic profile of NDV. The results demonstrated the incorporation of cellular proteins in NDV particles, which provides valuable information for elucidating viral infection and pathogenesis.

2012-01-01

45

Histone hyperacetylation can induce unfolding of the nucleosome core particle.  

PubMed Central

A direct correlation exists between the level of histone H4 hyperacetylation induced by sodium butyrate and the extent to which nucleosomes lose their compact shape and become elongated (62.0% of the particles have a length/width ratio over 1.6; overall mean in the length/width ratio = 1.83 +/- 0.48) when bound to electron microscope specimen grids at low ionic strength (1mM EDTA, 10mM Tris, pH 8.0). A marked proportion of elongated core particles is also observed in the naturally occurring hyperacetylated chicken testis chromatin undergoing spermatogenesis when analyzed at low ionic strength (36.8% of the particles have a length/width ratio over 1.6). Core particles of elongated shape (length/width ratio over 1.6) generated under low ionic strength conditions are absent in the hypoacetylated chicken erythrocyte chromatin and represent only 2.3% of the untreated Hela S3 cell core particles containing a low proportion of hyperacetylated histones. The marked differences between control and hyperacetylated core particles are absent if the particles are bound to the carbon support film in the presence of 0.2 M NaCl, 6mM MgCl2 and 10mM Tris pH 8.0, conditions known to stabilize nucleosomes. A survey of the published work on histone hyperacetylation together with the present results indicate that histone hyperacetylation does not produce any marked disruption of the core particle 'per se', but that it decreases intranucleosomal stabilizing forces as judged by the lowered stability of the hyperacetylated core particle under conditions of shearing stress such as cationic competition by the carbon support film of the EM grid for DNA binding. Images

Oliva, R; Bazett-Jones, D P; Locklear, L; Dixon, G H

1990-01-01

46

Immunotherapy of Human Papilloma Virus Induced Disease  

PubMed Central

Immunotherapy is the generic name for treatment modalities aiming to reinforce the immune system against diseases in which the immune system plays a role. The design of an optimal immunotherapeutic treatment against chronic viruses and associated diseases requires a detailed understanding of the interactions between the target virus and its host, in order to define the specific strategies that may have the best chance to deliver success at each stage of disease. Recently, a first series of successes was reported for the immunotherapy of Human Papilloma Virus (HPV)-induced premalignant diseases but there is definitely room for improvement. Here I discuss a number of topics that in my opinion require more study as the answers to these questions allows us to better understand the underlying mechanisms of disease and as such to tailor treatment.

van der Burg, Sjoerd H

2012-01-01

47

Comparison of toroidicity-induced Alfvén eigenmodes and energetic particle modes by gyrokinetic particle simulations  

NASA Astrophysics Data System (ADS)

This work reports on linear global gyrokinetic particle simulations of the excitation of toroidicity-induced Alfvén eigenmodes (TAE) and energetic particle modes (EPM), and the comparison between these two modes. The TAE excitation by antenna clarifies the magnetohydrodynamic (MHD) mode structure and the discrete eigenmode exists in the gap between the upper and lower accumulation points. The TAE excitation by fast ions modifies the MHD mode structure because of radial symmetry breaking and the eigenmode frequency moves towards the lower accumulation point. The phase space structure of fast ions shows that both passing and trapped particles contribute to the TAE excitation and that trapped particles dominate the wave-particle resonance in our simulations. The growth rate of TAE is sensitive to the fast ion energy, density, and density gradient, which are also important factors contributing to the transition of the TAE to the EPM. The gyrokinetic particle simulations also confirm the excitation of EPM when the drive is stronger. The frequency of the EPM is determined by the characteristic frequencies of fast ion motion in toroidal geometry.

Zhang, Chenxi; Zhang, Wenlu; Lin, Zhihong; Li, Ding

2013-05-01

48

Noise-induced vortex reversal of self-propelled particles  

NASA Astrophysics Data System (ADS)

We report an interesting phenomenon of noise-induced vortex reversal in a two-dimensional system of self-propelled particles (SPPs) with soft-core interactions. With the aid of forward flux sampling, we analyze the configurations along the reversal pathway and thus identify the mechanism of vortex reversal. We find that the reversal exhibits a hierarchical process: those particles at the periphery first change their motion directions, and then more inner layers of particles reverse later on. Furthermore, we calculate the dependence of the average reversal rate on noise intensity D and the number N of SPPs. We find that the rate decreases exponentially with the reciprocal of D. Interestingly, the rate varies nonmonotonically with N and a local minimal rate exists for an intermediate value of N.

Chen, Hanshuang; Hou, Zhonghuai

2012-10-01

49

Spinning Convection: Particle-induced Secondary Flow in Straight Microchannels  

NASA Astrophysics Data System (ADS)

In microfluidic systems, flow is generally approximated with Stokes flow and inertial forces are assumed negligible. However, at finite Reynolds number (small, yet non-zero), inertial forces have been shown to be useful, for instance by causing randomly distributed particles to order on specific lateral equilibrium positions in a confined flow. To further study these inertial effects at the microfluidic scale, we investigated the local disturbances induced by spinning particles in straight microchannels. We observe, numerically and experimentally, unexpected net cross-stream disturbances that generate a unique secondary flow pattern, which resembles the well-known Dean flow in curved channels. This behavior requires fluid inertia and micro-particles offset from the channel center, spinning due to the local shear rate across the particle. This phenomenon provides a novel technique for fluid transfer and solution switching in microsystems. Compared to other microfluidic mixing approaches the technique requires a simple channel geometry, with no external forces for operation, enabling biological applications in which the cells present within the flow themselves can induce the fluid transfer required for labeling, lysis, and other high-throughput sample preparations.

Amini, Hamed; Sollier, Elodie; di Carlo, Dino

2010-11-01

50

Multispectral-diode-laser-induced fluorescence biological particle sensor  

Microsoft Academic Search

Laser-induced fluorescence (LIF) provides a real-time technique for detecting micron-size airborne pathogens. Early LIF biological particle sensors used harmonic generation of UV in solid-state lasers to excite fluorescence. UV diode lasers have several key advantages over traditional lasers: a greater selection of wavelengths for the efficient and selective excitation of specific fluorescent biological compounds; continuous output so that all sampled

Geoffrey A. Wilson; Richard K. DeFreez

2004-01-01

51

Theory of trapped-particle-induced resistive fluid turbulence  

SciTech Connect

A theory of anomalous electron heat transport, evolving from trapped-particle-induced resistive interchange modes, is proposed. These latter are a new branch of the resistive interchange-ballooning family of instabilities, destabilized when the pressure carried by the unfavorably-drifting trapped particles is sufficiently large to overcome stabilizing contributions coming from favorable average curvature. Expressions for the turbulent heat diffusivity and anomalous electron thermal conductivity at saturation are derived for two regimes of trapped particle energy: (1) a moderately-energetic regime, which is ''fluid-like'' in the sense that the unstable mode grows faster than the time that it takes for particles in this energy range to precess once around the torus; and (2) a highly-energetic regime, where the trapped species has sufficiently high energy as to be able to resonantly interact with the mode. Unlike previous theories of anomalous transport, the estimates of diffusion and transport obtained here are self-consistent, since the trapped particles do not ''see'' the magnetic flutter due to their rapid bounce motion. The theory is valid for moderate electron-temperature, high ion-temperature (auxiliary-heated) plasmas, and as such, is relevant for present and future-generation experimental fusion devices.

Biglari, H.; Diamond, P.H.

1987-05-01

52

Theory of trapped-particle-induced resistive fluid turbulence  

SciTech Connect

A theory of anomalous electron heat transport, evolving from trapped-particle-induced resistive interchange modes, is proposed. The latter are a new branch of the resistive interchange-ballooning family of instabilities, destabilized when the pressure carried by the unfavorably drifting trapped particles is sufficiently large to overcome stabilizing contributions coming from favorable average curvature. Expressions for the turbulent heat diffusivity and anomalous electron thermal conductivity at saturation are derived for two regimes of trapped-particle energy: (I) a moderately energetic regime, which is ''fluidlike'' in the sense that the unstable mode grows faster than the time that it takes for particles in this energy range to precess once around the torus, and (II) a highly energetic regime, where the trapped species has sufficiently high energy as to be able to interact resonantly with the mode. Unlike previous theories of anomalous transport, the estimates of diffusion and transport obtained here are self-consistent since the trapped particles do not ''see'' the magnetic flutter due to their rapid bounce motion. The theory is valid for moderate electron-temperature, high ion-temperature (auxiliary heated) plasmas and as such, is relevant for present- and future-generation experimental fusion devices.

Biglari, H.; Diamond, P.H.

1987-12-01

53

Multispectral-diode-laser-induced fluorescence biological particle sensor  

NASA Astrophysics Data System (ADS)

Laser-induced fluorescence (LIF) provides a real-time technique for detecting micron-size airborne pathogens. Early LIF biological particle sensors used harmonic generation of UV in solid-state lasers to excite fluorescence. UV diode lasers have several key advantages over traditional lasers: a greater selection of wavelengths for the efficient and selective excitation of specific fluorescent biological compounds; continuous output so that all sampled particles are interrogated; and the ability to combine several UV diode lasers emitting at different wavelengths into a compact multiple-wavelength source for simultaneously exciting several biofluorophores. The coincident detection of multiple biofluorophores is expected to markedly improve discrimination of airborne pathogens from non-biological background aerosols. In this paper, we describe BioLert 2x16C5+1 - a LIF bio-particle sensor with two diode lasers, detection of sixteen fluorescence emission bands bundled into five user-defined linear combinations, and an elastic scatter detector. BioLert 2x16C5+1 also features fluorescence photon counting for sensitivity sufficient to distinguish between single bacterial spores and similar size inert particles, improved signal processing for optimally distinguishing between airborne pathogens and harmless particles, and a highly integrated air sampling system.

Wilson, Geoffrey A.; DeFreez, Richard K.

2004-12-01

54

Surveillance of drug induced diseases in children  

Microsoft Academic Search

A hospital based prospective study on drug induced diseases (DID) in children below 14 years of age was done for a duration\\u000a of two years. A total number of 20,310 patients were examined in pediatric department during this period, out of which 204\\u000a (1.004%) patients were diagnosed as DID. Children with severe reactions were admitted in pediatric ward, for in

K. P. Kushwaha; R. B. Verma; Y. D. Singh; A. K. Rathi

1994-01-01

55

Eugenol attenuates pulmonary damage induced by diesel exhaust particles.  

PubMed

Environmentally relevant doses of inhaled diesel particles elicit pulmonary inflammation and impair lung mechanics. Eugenol, a methoxyphenol component of clove oil, presents in vitro and in vivo anti-inflammatory and antioxidant properties. Our aim was to examine a possible protective role of eugenol against lung injuries induced by diesel particles. Male BALB/c mice were divided into four groups. Mice received saline (10 ?l in; CTRL group) or 15 ?g of diesel particles DEP (15 ?g in; DIE and DEUG groups). After 1 h, mice received saline (10 ?l; CTRL and DIE groups) or eugenol (164 mg/kg; EUG and DEUG group) by gavage. Twenty-four hours after gavage, pulmonary resistive (?P1), viscoelastic (?P2) and total (?Ptot) pressures, static elastance (Est), and viscoelastic component of elastance (?E) were measured. We also determined the fraction areas of normal and collapsed alveoli, amounts of polymorpho- (PMN) and mononuclear cells in lung parenchyma, apoptosis, and oxidative stress. Est, ?P2, ?Ptot, and ?E were significantly higher in the DIE than in the other groups. DIE also showed significantly more PMN, airspace collapse, and apoptosis than the other groups. However, no beneficial effect on lipid peroxidation was observed in DEUG group. In conclusion, eugenol avoided changes in lung mechanics, pulmonary inflammation, and alveolar collapse elicited by diesel particles. It attenuated the activation signal of caspase-3 by DEP, but apoptosis evaluated by TUNEL was avoided. Finally, it could not avoid oxidative stress as indicated by malondialdehyde. PMID:22194320

Zin, Walter A; Silva, Ana G L S; Magalhães, Clarissa B; Carvalho, Giovanna M C; Riva, Douglas R; Lima, Crystianne C; Leal-Cardoso, Jose H; Takiya, Christina M; Valença, Samuel S; Saldiva, Paulo H N; Faffe, Débora S

2011-12-22

56

Autophagy in alcohol-induced liver diseases  

PubMed Central

Alcohol is the most abused substance worldwide and a significant source of liver injury; the mechanisms of alcohol-induced liver disease are not fully understood. Significant cellular toxicity and impairment of protein synthesis and degradation occur in alcohol-exposed liver cells, along with changes in energy balance and modified responses to pathogens. Autophagy is the process of cellular catabolism through the lysosomal-dependent machinery, which maintains a balance among protein synthesis, degradation, and recycling of self. Autophagy is part of normal homeostasis and it can be triggered by multiple factors that threaten cell integrity including starvation, toxins, or pathogens. Multiple factors regulate autophagy; survival and preservation of cellular integrity at the expense of inadequately-folded proteins and damaged high energy-generating intracellular organelles are prominent targets of autophagy in pathologic conditions. Coincidentally, inadequately-folded proteins accumulate and high energy-generating intracellular organelles, such as mitochondria, are damaged by alcohol abuse; these alcohol-induced pathological findings prompted investigation of the role of autophagy in the pathogenesis of alcohol-induced liver damage. Our review summarizes the current knowledge about the role and implications of autophagy in alcohol-induced liver disease.

Dolganiuc, Angela; Thomes, Paul G.; Ding, Wen-Xing; Lemasters, John J.; Donohue, Terrence M.

2013-01-01

57

Apoptosis in animal models of virus-induced disease  

Microsoft Academic Search

Apoptosis is associated with virus-induced human diseases of the central nervous system, heart and liver, and causes substantial morbidity and mortality. Although virus-induced apoptosis is well characterized in individual cells in cell culture, virus-induced apoptosis in vivo and the role of apoptosis in virus-induced disease is not well established. This Review focuses on animal models of virus-induced diseases of the

Kenneth L. Tyler; Penny Clarke

2009-01-01

58

SENSITIZATION AND EXACERBATION OF ALLERGIC DISEASES BY DIESEL ENGINE PARTICLES  

SciTech Connect

Most studies of the health effects of diesel exhaust have focused on the controversial issue of its role in cancer. However, recently the role of combustion products such as diesel exhaust particles (DEP) in modulating the immune response has garnered much attention. In particular the effect of DEP on allergic and asthmatic diseases has been the focus of many studies. A link between industrialization and allergic disease has long been presumed. Indeed, only 50 years after the first recorded reported case of allergy in 1819, Charles Blackely wrote that the ''hay-fever epidemic'' was associated with the movement of people from the country into the cities. Ishizaki et al. (1987) found that people in Japan living on busy roads lined with cedar trees have more allergies to cedar than residents living on similar streets with much less traffic. Since that time other epidemiological studies have reported similar findings. Kramer, et al., showed that hay fever is greater in residential areas with heavy truck traffic, while Weiland, et al., reported that allergic symptoms correlate with the distance of residences to roads with heavy traffic.

Diaz-Sanchez, David

2000-08-20

59

Retrovirus-induced disease in poultry.  

PubMed

Three species of avian retrovirus cause disease in poultry: the avian leukosis/sarcoma virus (ALSV), reticuloendotheliosis virus (REV), and lymphoproliferative disease virus (LPDV) of turkeys. The ALSV can be classified as slowly transforming viruses, which lack a viral oncogene, and acutely transforming viruses, which possess a viral oncogene. Slowly transforming viruses induce late onset leukoses of the B cell lymphoid, erythroid, and myeloid cell lineages, and other tumors, by viral promoter insertion into the genome of a host cell and activation of a cellular protooncogene. The various acutely transforming leukemia and sarcoma viruses induce leukotic or other tumors rapidly and carry one or anther (sometimes two) viral oncogenes, of which some 15 have been identified. The ALSV fall into six envelope subgroups, A through E, and the recently recognized J subgroup, which induces myeloid leukosis. With the exception of Subgroup E viruses, these viruses spread vertically and horizontally as infectious virions, and are termed exogenous viruses. Subgroup E viruses are usually spread genetically as DNA proviruses (often defective) in host germ cell genome, and are termed endogenous viruses. Several other families of endogenous viruses also exist, one of which, endogenous avian retrovirus (EAV), is related to Subgroup J ALV. Exogenous viruses, and sometimes endogenous viruses, can have detrimental effects on commercially important production traits. Exogenous viruses are currently controlled by virus eradication schemes. Reticuloendotheliosis virus, which lacks a viral oncogene, causes chronic B cell and T-cell lymphomas in chickens, and also chronic lymphomas in turkeys and other species of birds. An acutely transforming variant of REV, Strain T, carries a viral oncogene, and induces reticuloendotheliosis within a few days. In chickens and turkeys, REV spreads vertically and horizontally. No commercial control schemes are operated. In turkeys, LPDV infection has occurred in several countries, where it caused a lymphoproliferative disease of uncertain nature. PMID:9706091

Payne, L N

1998-08-01

60

Glucocorticoid-induced osteoporosis in rheumatic diseases  

PubMed Central

The aim of this article is to review rheumatological diseases that are associated with glucocorticoid?induced osteoporosis or fractures and to perform a critical analysis of the current guidelines and treatment regimens. The electronic database MEDLINE was searched using the date range of July 1986 to June 2009 and the following search terms: osteoporosis, bone mineral density, fractures, systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, vasculitis, juvenile rheumatoid arthritis, juvenile idiopathic arthritis and juvenile dermatomyositis. Osteopenia and osteoporosis respectively account for 1.4 to 68.7% and 5.0 to 61.9% of adult rheumatological diseases. Among juvenile rheumatological disorders, the frequency of low bone mass ranges from 38.7 to 70%. In general, fracture rates vary from 0 to 25%. Although glucocorticoid?induced osteoporosis has a high rate of prevalence among rheumatic diseases, a relatively low number of patients on continuous glucocorticoid treatment receive adequate diagnostic evaluation or preventive therapy. This deficit in patient care may result from a lack of clear understanding of the attributed risks by the patients and physicians, the high complexity of the treatment guidelines and poor patient compliance.

Pereira, Rosa Maria Rodrigues; de Carvalho, Jozelio Freire; Canalis, Ernesto

2010-01-01

61

Induced radioactivity in and around high-energy particle accelerators.  

PubMed

Particle accelerators and their surroundings are locations of residual radioactivity production that is induced by the interaction of high-energy particles with matter. This paper gives an overview of the principles of activation caused at proton accelerators, which are the main machines operated at Conseil Européen pour la Recherche Nucléaire. It describes the parameters defining radio-nuclide production caused by beam losses. The second part of the paper concentrates on the analytic calculation of activation and the Monte Carlo approach as it is implemented in the FLUKA code. Techniques used to obtain, on the one hand, estimates of radioactivity in Becquerel and, on the other hand, residual dose rates caused by the activated material are discussed. The last part of the paper focuses on experiments that allow for benchmarking FLUKA activation calculations and on simulations used to predict activation in and around high-energy proton machines. In that respect, the paper addresses the residual dose rate that will be induced by proton-proton collisions at an energy of two times 7 TeV in and around the Compact Muon Solenoid (CMS) detector. Besides activation of solid materials, the air activation expected in the CMS cavern caused by this beam operation is also discussed. PMID:21697180

Vincke, Helmut; Theis, Chris; Roesler, Stefan

2011-06-22

62

Heavy charged-particle induced lesions in rabbit cerebral cortex  

SciTech Connect

Fourteen male rabbits received single doses of 20, 40, and 80 Gy of neon irradiation with an extended Bragg peak. They were sacrificed at 1 day, 1 week, and 6 months post-irradiation. The tissue changes which showed a significant time-dose relationship were leakage of carbon particles from blood vessels, focal arachnoiditis, hemorrhage, cystic necrosis, and a total histopathologic score using a point system of grading. The focal nature of the lesions was clearly demonstrated with 2 mm thick macrotome sections. The transition zone between damaged brain and microscopically normal appearing brain was less than 1 mm and the tissue damage induced was morphologically similar to that of other radiation modalities. These findings may have important therapeutic implications for patients. The sharply demarcated boundaries of heavy charged-particle induced lesions suggest these beams will be useful for obliterating tissue in areas where it is critical that a transition from undamaged to severely damaged tissue must occur over a short distance, such as in the central nervous system.

Woodruff, K.H.; Lyman, J.T.; Fabrikant, J.I.

1988-02-01

63

Subway particles are more genotoxic than street particles and induce oxidative stress in cultured human lung cells.  

PubMed

Epidemiological studies have shown an association between airborne particles and a wide range of adverse health effects. The mechanisms behind these effects include oxidative stress and inflammation. Even though traffic gives rise to high levels of particles in the urban air, people are exposed to even higher levels in the subway. However, there is a lack of knowledge regarding how particles from different urban subenvironments differ in toxicity. The main aim of the present study was to compare the ability of particles from a subway station and a nearby very busy urban street, respectively, to damage DNA and to induce oxidative stress. Cultured human lung cells (A549) were exposed to particles, DNA damage was analyzed using single cell gel electrophoresis (the comet assay), and the ability to induce oxidative stress was measured as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation in lung cell DNA. We found that the subway particles were approximately eight times more genotoxic and four times more likely to cause oxidative stress in the lung cells. When the particles, water extracts from the particles, or particles treated with the metal chelator deferoxamine mesylate were incubated with 2'-deoxyguanosine (dG) and 8-oxodG was analyzed, we found that the oxidative capacity of the subway particles was due to redox active solid metals. Furthermore, analysis of the atomic composition showed that the subway particles to a dominating degree (atomic %) consisted of iron, mainly in the form of magnetite (Fe3O4). By using electron microscopy, the interaction between the particles and the lung cells was shown. The in vitro reactivity of the subway particles in combination with the high particle levels in subway systems give cause of concern due to the high number of people that are exposed to subway particles on a daily basis. To what extent the subway particles cause health effects in humans needs to be further evaluated. PMID:15651844

Karlsson, Hanna L; Nilsson, Lennart; Möller, Lennart

2005-01-01

64

Ionizing Radiation-induced Diseases in Korea  

PubMed Central

Radiation risk has become well known through epidemiological studies of clinically or occupationally exposed populations, animal experiments, and in vitro studies; however, the study of radiation related or induced disease has been limited in Korea. This study is to find the level of occupational radiation exposure for various kinds of accidents, compensated occupational diseases, related studies, and estimations on future occupational disease risks. Research data of related institutions were additionally investigated. About 67% of 62,553 radiation workers had no exposure or less than 1.2 mSv per year. The 5 reported cases on radiation accident patients in Korea occurred during nondestructive testing. According to the recent rapid increase in the number of workers exposed to radiation, a higher social recognition of cancer, and an increasing cancer mortality rate, it is expected that occupational disease compensation will rapidly increase as well. Therefore, it is important to develop scientific and objective decision methods, such as probability of causation and screening dose in the establishment of an exposure and health surveillance system.

Jeong, Meeseon; Moon, Kieun; Jo, Min-Heui; Kang, Seong-Kyu

2010-01-01

65

Titanium particles stimulate COX-2 expression in synovial fibroblasts through an oxidative stress-induced, calpain-dependent, NF-?B pathway  

PubMed Central

In prosthetic loosening, bone resorption is induced by wear debris particles generated from the artificial joint articulation. Our prior work showed that synovial-like fibroblasts respond to titanium particles by producing receptor activator of NF-?B ligand (RANKL), a critical activator of osteoclastogenesis. While this effect occurs through a cyclooxygenase-2 (COX-2)-dependent pathway, the mechanism of COX-2 stimulation by titanium particles is not clear. Here we show that titanium particles induce COX-2 gene expression by activating NF-?B signaling. Inhibitor of NF-?B (I?B?) is degraded following particle treatment, permitting active NF-?B to translocate to the nucleus where it interacts with the COX-2 promoter and drives transcription. NF-?B activation is dependent on reactive oxygen species since antioxidants block the NF-?B signaling induced by particles. Surprisingly, I?B? degradation is independent of IKK (I?B kinase) and the 26S proteasome. Instead, calpain inhibitor can block the I?B? degradation induced by particles. Furthermore, the calpain-targeted COOH-terminal PEST sequence of I?B? is necessary for phosphorylation and degradation, consistent with a proteasome-independent mechanism of catabolism. Altogether, the data demonstrate a signaling pathway by which titanium particles induce oxidative stress, stimulate calpain-mediated NF-?B activation, and activate target gene expression, including COX-2. These findings define important targets for osteolysis but may also have importance in other diseases where fibroblasts respond to environmental particles, including pulmonary diseases.

Wei, Xiaochao; Zhang, Xinping; Flick, Lisa M.; Drissi, Hicham; Schwarz, Edward M.; O'Keefe, Regis J.

2009-01-01

66

Nilotinib-induced interstitial lung disease.  

PubMed

Nilotinib is a second-generation tyrosine kinase inhibitor active in patients with chronic myeloid leukemia (CML) resistant to imatinib, and has been recently approved for newly diagnosed patients. We present a case of nilotinib-induced interstitial lung disease (ILD). A 67-year-old female patient was initially treated with imatinib for chronic-phase Philadelphia chromosome-positive (Ph(+)) CML. Imatinib was replaced by nilotinib because of hematological toxicity. The patient had received nilotinib for about 3 years without significant adverse effects. She visited the clinic due to chronic cough; chest X-ray revealed consolidations in both lung fields. Nilotinib-induced ILD was diagnosed based on intensive workup, including lung biopsy. She responded dramatically to corticosteroid therapy. To our knowledge, this is the first reported case of nilotinib-induced ILD in a patient with Ph(+) CML. We emphasize that if unexplained lung abnormalities progress in patients receiving nilotinib, physicians should consider this potentially fatal complication in their differential diagnoses. PMID:23877149

Go, Se-Il; Lee, Won Sup; Lee, Gyeong-Won; Kang, Jung Hun; Kang, Myung Hee; Lee, Jeong-Hee; Kim, Hoon-Gu

2013-07-23

67

Diesel exhaust particles induce the over expression of tumor necrosis factor-alpha (TNF-alpha) gene in alvelor machrophage and failed to induce apoptosis through activation of nuclear factor-kappaB (NF-kappaB)  

EPA Science Inventory

Exposure to particulate matter (PM2.5-10), including diesel exhaust particles (DEP) has been reported to induce lung injury and exacerbation of asthma and chronic obstructive pulmonary disease. Alveolar macrophages play a major role in the lung's response to inhaled particles and...

68

Diesel exhaust particles induce endothelial dysfunction in apoE{sup -/-} mice  

SciTech Connect

Background: Particulate air pollution can aggravate cardiovascular disease by mechanisms suggested to involve translocation of particles to the bloodstream and impairment of endothelial function, possibly dependent on present atherosclerosis. Aim: We investigated the effects of exposure to diesel exhaust particles (DEP) in vivo and ex vivo on vasomotor functions in aorta from apoE{sup -/-} mice with slight atherosclerosis and from normal apoE{sup +/+} mice. Methods: DEP 0, 0.5 or 5 mg/kg bodyweight in saline was administered i.p. The mice were sacrificed 1 h later and aorta ring segments were mounted on wire myographs. Segments from unexposed mice were also incubated ex vivo with 0, 10 and 100 {mu}g DEP/ml before measurement of vasomotor functions. Results: Exposure to 0.5 mg/kg DEP in vivo caused a decrease in the endothelium-dependent acetylcholine elicited vasorelaxation in apoE{sup -/-} mice, whereas the response was enhanced in apoE{sup +/+} mice. No significant change was observed after administration of 5 mg/kg DEP. In vivo DEP exposure did not affect constriction induced by K{sup +} or phenylephrine. In vitro exposure to 100 {mu}g DEP/ml enhanced acetylcholine-induced relaxation and attenuated phenylephrine-induced constriction. Vasodilation induced by sodium nitroprusside was not affected by any DEP exposure. Conclusion: Exposure to DEP has acute effect on vascular functions. Endothelial dysfunction possibly due to decreased NO production as suggested by decreased acetylcholine-induced vasorelaxation and unchanged sodium nitroprusside response can be induced by DEP in vivo only in vessels of mice with some atherosclerosis.

Hansen, Christian S. [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark); Sheykhzade, Majid [Department of Pharmacology and Pharmacotherapy, Danish University of Pharmaceutical Sciences (Denmark); Moller, Peter [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark); Folkmann, Janne Kjaergaard [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark); Amtorp, Ole [Department of Pharmacology, University of Copenhagen (Denmark); Jonassen, Thomas [Department of Pharmacology, University of Copenhagen (Denmark); Loft, Steffen [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark)]. E-mail: s.loft@pubhealth.ku.dk

2007-02-15

69

The clearance of colloidal particles by Kupffer cells in collagen disease.  

PubMed

The Kupffer cells clearance of colloidal 198Au particles with a diameter of 200-300 A was estimated in 14 subjects with different collagen diseases: 7 without previous treatment and 7 under immunodepressive treatment compared to 10 controls. No difference between the subjects with collagen disease and controls was observed. The group with collagen disease under immunodepressive treatment has lower Kupffer cells clearance for colloidal gold particles than non-treated patients, without statistical significance. PMID:2094346

Dumitra?cu, D L; Szanto, P; Cotul, S; Tama?, S; Dumitra?cu, D

70

Iron-Induced Fibrin in Cardiovascular Disease  

PubMed Central

Accumulating evidence within the last two decades indicates the association between cardiovascular disease (CVD) and chronic inflammatory state. Under normal conditions fibrin clots are gradually degraded by the fibrinolytic enzyme system, so no permanent insoluble deposits remain in the circulation. However, fibrinolytic therapy in coronary and cerebral thrombosis is ineffective unless it is installed within 3-5 hours of the onset. We have shown that trivalent iron (FeIII) initiates a hydroxyl radical-catalyzed conversion of fibrinogen into a fibrin-like polymer (parafibrin) that is remarkably resistant to the proteolytic dissolution and thus promotes its intravascular deposition. Here we suggest that the persistent presence of proteolysis-resistant fibrin clots causes chronic inflammation. We study the effects of certain amphiphilic substances on the iron- and thrombin-induced fibrinogen polymerization visualized using scanning electron microscopy. We argue that the culprit is an excessive accumulation of free iron in blood, known to be associated with CVD. The only way to prevent iron overload is by supplementation with iron chelating agents. However, administration of free radical scavengers as effective protection against persistent presence of fibrin-like deposits should also be investigated to contribute to the prevention of cardiovascular and other degenerative diseases.

Lipinski, Boguslaw; Pretorius, Etheresia

2013-01-01

71

Ultrafine particles from diesel engines induce vascular oxidative stress via JNK activation.  

PubMed

Exposure to particulate air pollution is linked to increased incidences of cardiovascular diseases. Ambient ultrafine particles (UFP) from diesel vehicle engines have been shown to be proatherogenic in ApoE knockout mice and may constitute a major cardiovascular risk in humans. We posited that circulating nano-sized particles from traffic pollution sources induce vascular oxidative stress via JNK activation in endothelial cells. Diesel UFP were collected from a 1998 Kenworth truck. Intracellular superoxide assay revealed that these UFP dose-dependently induced superoxide (O(2)(-)) production in human aortic endothelial cells (HAEC). Flow cytometry showed that UFP increased MitoSOX red intensity specific for mitochondrial superoxide. Protein carbonyl content was increased by UFP as an indication of vascular oxidative stress. UFP also up-regulated heme oxygenase-1 (HO-1) and tissue factor (TF) mRNA expression, and pretreatment with the antioxidant N-acetylcysteine significantly decreased their expression. Furthermore, UFP transiently activated JNK in HAEC. Treatment with the JNK inhibitor SP600125 and silencing of both JNK1 and JNK2 with siRNA inhibited UFP-stimulated O(2)(-) production and mRNA expression of HO-1 and TF. Our findings suggest that JNK activation plays an important role in UFP-induced oxidative stress and stress response gene expression. PMID:19154785

Li, Rongsong; Ning, Zhi; Cui, Jeffery; Khalsa, Bhavraj; Ai, Lisong; Takabe, Wakako; Beebe, Tyler; Majumdar, Rohit; Sioutas, Constantinos; Hsiai, Tzung

2008-12-11

72

Ultra Fine Particles from Diesel Engines Induce Vascular Oxidative Stress via JNK Activation  

PubMed Central

Exposure of particulate air pollution is linked to increased incidences of cardiovascular diseases. Ambient ultra fine particles (UFP) from diesel vehicle engines have been shown to be pro-atherogenic in apoE knockout mice and may constitute a major cardiovascular risk in humans. We posited that circulating nano-sized particles from traffic pollution sources induced vascular oxidative stress via JNK activation in endothelial cells. Diesel UFP were collected from a 1998 Kenworth truck. Intra-cellular superoxide assay revealed that these UFP dose-dependently induced superoxide (O2·-) production in human aortic endothelial cells (HAEC). Flow cytometry (FACS) showed that UFP increased MitoSOX Red intensity specific for mitochondrial superoxide. Protein carbonyl content is increased by UFP as an indication of vascular oxidative stress. UFP also up-regulated hemeoxygenase-1 (HO-1) and tissue factor (TF) mRNA expression, and pre-treatment with antioxidant, N-acetyl cysteine (NAC), significantly decreased their expression. Furthermore, UFP transiently activated JNK in HAEC. Treatment with JNK inhibitor SP600125 and silencing of both JNK1 and JNK2 with siRNA inhibited UFP stimulated O2·- production and mRNA expression of HO-1 and TF. Our findings suggest that JNK activation play an important role in UFP-induced oxidative stress and stress response gene expression.

Li, Rongsong; Ning, Zhi; Cui, Jeffery; Khalsa, Bhavraj; Ai, Lisong; Takabe, Wakako; Beebe, Tyler; Majumdar, Rohit; Sioutas, Constantinos; Hsiai, Tzung

2011-01-01

73

Rheology of immiscible blends with particle-induced drop clusters  

Microsoft Academic Search

We consider the effects of 2.7-?m-diameter hydrophobic silica particles added to droplet–matrix blends of polyethylene oxide\\u000a (PEO) and polyisobutylene (PIB). The particles adsorb on the surface of the PEO drops but protrude considerably into the PIB\\u000a phase. Hence, it is possible for a single particle to adsorb onto two PEO drops simultaneously. Such particles are called\\u000a “bridging” particles, and they

Prachi Thareja; Sachin Velankar

2008-01-01

74

Apoptosis in animal models of virus-induced disease  

PubMed Central

Apoptosis is associated with virus-induced human diseases of the central nervous system, heart and liver, and causes substantial morbidity and mortality. Although virus-induced apoptosis is well characterized in individual cells in cell culture, virus-induced apoptosis in vivo and the role of apoptosis in virus-induced disease is not well established. This Review focuses on animal models of virus-induced diseases of the central nervous system, heart and liver that provide insights into the role of apoptosis in pathogenesis, the pathways involved and the potential therapeutic implications.

Clarke, Penny; Tyler, Kenneth L.

2009-01-01

75

The effect of flow geometry on shear-induced particle segregation and resuspension  

Microsoft Academic Search

In this thesis, we investigate through theory and experiment the influence of the flow geometry on various shear-induced migration phenomena such as particle demixing, viscous resuspension and meniscus accumulation for a suspension of rigid, non-colloidal particles. The major focus of this thesis is the elucidation of a particle flux mechanism that has been ignored in the literature in the theoretical

Arun Ramachandran

2007-01-01

76

Particle-induced bit errors in high performance fiber optic data links for satellite data management  

Microsoft Academic Search

Experimental test methods and analysis tools are demonstrated to assess particle-induced bit errors on fiber optic link receivers for satellites. Susceptibility to direct ionization from low LET particles is quantified by analyzing proton and helium ion data as a function of particle LET. Existing single event analysis approaches are shown to apply, with appropriate modifications, to the regime of temporally

P. W. Marshall; Cheryl J. Dale; Martin A. Carts; K. A. LaBel

1994-01-01

77

Induced-charge electroosmotic flow around dielectric particles in uniform electric field.  

PubMed

The current research of induced-charge electroosmotic flow (ICEOF) is mostly confined to systems with ideally or fully polarizable surfaces (e.g., metal). However, most materials in nature have various degrees of polarizability, which directly affects the induced charges and subsequently the induced-charge electroosmotic flow. This paper studied the effect of the polarizability of the materials on the ICEOF. An analytical expression of the induced potential on the surface of a dielectric particle in a uniform electrical field was derived. Three-dimensional transient numerical simulations of the ICEOF and the motion of dielectric particles were performed to study the effect of the polarizability. Simulation results show that the transportation of the dielectric particle in a microchannel is not affected by the polarizability of the particle; however, the interaction of two dielectric particles is sensitive to the polarizability of the particles. PMID:24034219

Zhang, Fang; Li, Dongqing

2013-08-22

78

DNA complex lesions induced by protons and ? -particles: track structure characteristics determining linear energy transfer and particle type dependence  

Microsoft Academic Search

The yield of DNA double-strand breaks (dsb) and DNA complex lesions induced by protons and ?-particles of various energies was simulated using a Monte Carlo track structure code (MOCA15) and a simple model of the DNA\\u000a molecule. DNA breaks of different complexity were analysed. The linear energy transfer (LET) and particle-type dependence\\u000a of lesions of higher complexity seems to confirm

A. Ottolenghi; M. Merzagora; H. G. Paretzke

1997-01-01

79

Induced sputum, exhaled nitric oxide, and particles in exhaled air in assessing airways inflammation in occupational exposures.  

PubMed

Sensitive methods to detect airways inflammation caused by exposures associated with adverse respiratory effects are crucial, as is the identification of individuals with early-stage disease. In this review, the use of induced sputum and sampling of the fraction of nitric oxide to identify airways inflammation associated with occupational exposures is discussed. In addition, a new method to assess airways inflammation in small airways (sampling and analyses of particles in exhaled air) is introduced. PMID:23153615

Olin, Anna-Carin

2012-12-01

80

Purification, characterization and serological detection of virus-like particles associated with banana bunchy top disease in Australia.  

PubMed

Isometric virus-like particles, 18 nm in diameter, have been isolated from banana (Musa spp.) affected by bunchy top disease in Australia. Banana bunchy top disease-associated virus-like particles (BBTV) banded as a single component with buoyant density of 1.28 to 1.29 g/ml in Cs2SO4 and sedimented at about 46S in isokinetic sucrose density gradients. The A260/A280 of purified preparations was about 1.33. A single coat protein of Mr 20,500 was identified with antibodies to BBTV particles from Australia. Single-stranded DNA of about 1 kb as well as ssRNA smaller than 0.45 kb was also associated with the particles. A polyclonal antiserum to BBTV, suitable for use in ELISA, was prepared. Stability and antigenicity of purified BBTV was impaired by storage at pH greater than or equal to 8.5 and freezing at -20 degrees C without protectants. BBTV was detected by double antibody sandwich-ELISA with monoclonal and polyclonal antibodies, in field-infected banana plants, single aphids from an infective colony, and in experimentally aphid-inoculated banana plants. After transmission of BBTV particles by aphids from a banana bunchy top disease-affected to an uninfected banana plant, the disease was induced and BBTV was detected by ELISA in symptomatic leaves only. BBTV isolates from Australia, Taiwan, People's Republic of China, Tonga, Western Samoa and Hawaii were found to be serologically related, which suggests a common aetiology for the disease. PMID:1993863

Thomas, J E; Dietzgen, R G

1991-02-01

81

Toxicogenomic analysis of the particle dose- and size-response relationship of silica particles-induced toxicity in mice.  

PubMed

This study investigated the relationship between particle size and toxicity of silica particles (SP) with diameters of 30, 70, and 300 nm, which is essential to the safe design and application of SP. Data obtained from histopathological examinations suggested that SP of these sizes can all induce acute inflammation in the liver. In vivo imaging showed that intravenously administrated SP are mainly present in the liver, spleen and intestinal tract. Interestingly, in gene expression analysis, the cellular response pathways activated in the liver are predominantly conserved independently of particle dose when the same size SP are administered or are conserved independently of particle size, surface area and particle number when nano- or submicro-sized SP are administered at their toxic doses. Meanwhile, integrated analysis of transcriptomics, previous metabonomics and conventional toxicological results support the view that SP can result in inflammatory and oxidative stress, generate mitochondrial dysfunction, and eventually cause hepatocyte necrosis by neutrophil-mediated liver injury. PMID:23221170

Lu, Xiaoyan; Jin, Tingting; Jin, Yachao; Wu, Leihong; Hu, Bin; Tian, Yu; Fan, Xiaohui

2012-12-10

82

Toxicogenomic analysis of the particle dose- and size-response relationship of silica particles-induced toxicity in mice  

NASA Astrophysics Data System (ADS)

This study investigated the relationship between particle size and toxicity of silica particles (SP) with diameters of 30, 70, and 300 nm, which is essential to the safe design and application of SP. Data obtained from histopathological examinations suggested that SP of these sizes can all induce acute inflammation in the liver. In vivo imaging showed that intravenously administrated SP are mainly present in the liver, spleen and intestinal tract. Interestingly, in gene expression analysis, the cellular response pathways activated in the liver are predominantly conserved independently of particle dose when the same size SP are administered or are conserved independently of particle size, surface area and particle number when nano- or submicro-sized SP are administered at their toxic doses. Meanwhile, integrated analysis of transcriptomics, previous metabonomics and conventional toxicological results support the view that SP can result in inflammatory and oxidative stress, generate mitochondrial dysfunction, and eventually cause hepatocyte necrosis by neutrophil-mediated liver injury.

Lu, Xiaoyan; Jin, Tingting; Jin, Yachao; Wu, Leihong; Hu, Bin; Tian, Yu; Fan, Xiaohui

2013-01-01

83

Particle dispersion and mixing induced by breaking internal gravity waves  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to analyze diapycnal mixing induced by the breaking of an internal gravity wave — the primary wave — either standing or propagating. To achieve this aim we apply two different methods. The first method consists of a direct estimate of vertical eddy diffusion from particle dispersion while the second method relies upon potential energy budgets [Winters, K.B., Lombard, P.N., Riley, J.J., D'Asaro, E.A., 1995. J. Fluid Mech. 289, 115-128; Winters, K.B., D'Asaro, E.A., 1996. J. Fluid Mech. 317, 179-193]. The primary wave we consider is of small amplitude and is statically stable, a case for which the breaking process involves two-dimensional instabilities. The dynamics of the waves have been previously analyzed by means of two-dimensional direct numerical simulations [Bouruet-Aubertot, P., Sommeria, J., Staquet, C., 1995. J. Fluid Mech. 285, 265-301; Bouruet-Aubertot, P., Sommeria, J., Staquet, C., 1996. Dyn. Atmos. Oceans 29, 41-63; Koudella, C., Staquet, C., 1998. In: Davis, P. (Ed.), Proceedings of the IMA Conference on Mixing and Dispersion on Stably-stratified Flows, Dundee, September 1996. IMA Publication]. High resolution three-dimensional calculations of the same wave are also reported here [Koudella, C., 1999]. A local estimate of mixing is first inferred from the time evolution of sets of particles released in the flow during the breaking regime. We show that, after an early evolution dominated by shear effects, a diffusion law is reached and the dispersion coefficient is fairly independent of the initial seeding location of the particles in the flow. The eddy diffusion coefficient, K, is then estimated from the diapycnal diffusive flux. A good agreement with the value inferred from particle dispersion is obtained. This finding is of particular interest regarding the interpretation of in situ estimates of K inferred either from tracer dispersion or from microstructure measurements. Computation of the Cox number, equal to the ratio of eddy diffusivity to molecular diffusivity, shows that the Cox number varies within the interval [9, 262], which corresponds to the range of vertical eddy diffusivity measured in the interior of the ocean. The Cox number is found to depend on the turbulent Froude number squared. We show eventually that mixing results in a weak distortion of the initial density profile and we relate this result to observations made at small scale in the ocean. Comparisons between the analysis of the two-dimensional and high resolution (256 3) three-dimensional direct numerical simulations of the primary wave were also conducted. We show that the energetics and the amount of mixing are very close when the primary wave is of small amplitude. This results from the fact that, for a statically stable wave, the dynamics of the initially two-dimensional primary wave remains mostly two-dimensional even after the onset of wavebreaking.

Bouruet-Aubertot, Pascale; Koudella, C.; Staquet, C.; Winters, K. B.

2001-01-01

84

Stochastic electrodynamics with particle structure Part I: Zero-point induced Brownian behavior  

Microsoft Academic Search

If ordinary views on particle structure are introduced in a simple classical particle model in replacement of the point particles of standard use in stochastic electrodynamics, it can be shown that an internalZitterbewegung induced by the zero-point field background gives rise to a Brownian movement for the whole particle with a diffusion constant of the form D = ?\\/2mD ,

A. Rueda

1993-01-01

85

Influence of soot particle aggregation on time-resolved laser-induced incandescence signals  

Microsoft Academic Search

Laser-induced incandescence (LII) is a versatile technique for quantitative soot measurements in flames and exhausts. When\\u000a used for particle sizing, the time-resolved signals are analysed as these will show a decay rate dependent on the soot particle\\u000a size. Such an analysis has traditionally been based on the assumption of isolated primary particles. However, soot particles\\u000a in flames and exhausts are

H. Bladh; J. Johnsson; J. Rissler; H. Abdulhamid; N.-E. Olofsson; M. Sanati; J. Pagels; P.-E. Bengtsson

2011-01-01

86

Shear-induced alignment and dynamics of elongated granular particles.  

PubMed

The alignment, ordering, and rotation of elongated granular particles was studied in shear flow. The time evolution of the orientation of a large number of particles was monitored in laboratory experiments by particle tracking using optical imaging and x-ray computed tomography. The experiments were complemented by discrete element simulations. The particles develop an orientational order. In the steady state the time- and ensemble-averaged direction of the main axis of the particles encloses a small angle with the streamlines. This shear alignment angle is independent of the applied shear rate, and it decreases with increasing grain aspect ratio. At the grain level the steady state is characterized by a net rotation of the particles, as dictated by the shear flow. The distribution of particle rotational velocities was measured both in the steady state and also during the initial transients. The average rotation speed of particles with their long axis perpendicular to the shear alignment angle is larger, while shear aligned particles rotate slower. The ratio of this fast/slow rotation increases with particle aspect ratio. During the initial transient starting from an unaligned initial condition, particles having an orientation just beyond the shear alignment angle rotate opposite to the direction dictated by the shear flow. PMID:23214776

Börzsönyi, Tamás; Szabó, Balázs; Wegner, Sandra; Harth, Kirsten; Török, János; Somfai, Ellák; Bien, Tomasz; Stannarius, Ralf

2012-11-21

87

Virus-like particles associated with banana bunchy top disease contain small single-stranded DNA  

Microsoft Academic Search

Virus-like particles were purified from banana plants with banana bunchy top disease. These particles were isometric with a diameter of 18 to 20 nm and a density of 1.28 to 1-30 g\\/ml in caesium sulphate. Associated with these particles were an ssDNA of about 1 kb and one major protein of Mr 20100. DsDNA was synthe- sized from nucleic acid

Robert M. Harding; Thomas M. Burns; James L. Dale

1991-01-01

88

Thermally relativistic flows induced by gravitational-force-free particle motion in curved spacetime  

NASA Astrophysics Data System (ADS)

Thermally relativistic flows in the early Universe can be characterized by the emergence of flows induced by gravitational-force-free particle motion in curved spacetime as well as induced by the gravitational force. In this paper, thermally relativistic flows induced by gravitational-force-free particle motion in curved spacetime are discussed on the basis of the general relativistic Boltzmann equation. As an object of analysis, we consider the flow from the static state inside the Schwarzschild radius of a thermally relativistic stuffed black hole induced by such motion. Analytical results obtained using the collisionless, nongravitational general relativistic Boltzmann equation reveal that the initial cluster is induced by gravitational-force-free particle motion. Numerical results obtained using the nongravitational general relativistic Anderson-Witting model confirm the presence of an initial cluster inside the thermally relativistic stuffed black hole, which is induced by gravitational-force-free particle motion.

Yano, Ryosuke; Suzuki, Kojiro; Kuroda, Hisayasu

2009-12-01

89

Different particle determinants induce apoptosis and cytokine release in primary alveolar macrophage cultures  

PubMed Central

Background Particles are known to induce both cytokine release (MIP-2, TNF-?), a reduction in cell viability and an increased apoptosis in alveolar macrophages. To examine whether these responses are triggered by the same particle determinants, alveolar macrophages were exposed in vitro to mineral particles of different physical-chemical properties. Results The crystalline particles of the different stone types mylonite, gabbro, basalt, feldspar, quartz, hornfels and fine grain syenite porphyr (porphyr), with a relatively equal size distribution (? 10 ?m), but different chemical/mineral composition, all induced low and relatively similar levels of apoptosis. In contrast, mylonite and gabbro induced a marked MIP-2 response compared to the other particles. For particles of smaller size, quartz (? 2 ?m) seemed to induce a somewhat stronger apoptotic response than even smaller quartz (? 0.5 ?m) and larger quartz (? 10 ?m) in relation to surface area, and was more potent than hornfels and porphyr (? 2 ?m). The reduction in cell viability induced by quartz of the different sizes was roughly similar when adjusted to surface area. With respect to cytokines, the release was more marked after exposure to quartz ? 0.5 ?m than to quartz ? 2 ?m and ? 10 ?m. Furthermore, hornfels (? 2 ?m) was more potent than the corresponding hornfels (? 10 ?m) and quartz (? 2 ?m) to induce cytokine responses. Pre-treatment of hornfels and quartz particles ? 2 ?m with aluminium lactate, to diminish the surface reactivity, did significantly reduce the MIP-2 response to hornfels. In contrast, the apoptotic responses to the particles were not affected. Conclusion These results indicate that different determinants of mineral/stone particles are critical for inducing cytokine responses, reduction in cell viability and apoptosis in alveolar macrophages. The data suggest that the particle surface reactivity was critical for cytokine responses, but contributed less to cell death for the types of particles tested. The size-dependent variations, specially in cytokine release, seem not to be explained only by particle surface area.

Refsnes, Magne; Hetland, Ragna B; ?vrevik, Johan; Sundf?r, Idunn; Schwarze, Per E; Lag, Marit

2006-01-01

90

Particle Disease on Fluoride-18 (NaF) PET/CT imaging  

PubMed Central

Particle disease is a loss of bone that commonly occurs about five years after arthroplasty. The cause is secondary to microabrasive wear and shedding of any portion of the prosthesis, and the microscopic foreign bodies activate inflammation which can lead to pain. This report describes the imaging findings of an 80-year-old female with particle disease detected with 18F-fluoride PET/CT.

Kuo, Jonathan; Foster, Cameron; Shelton, David

2011-01-01

91

Metal-Induced Lung Disease. Lessons from Japan's Experience  

Microsoft Academic Search

Abstract: Metal-Induced Lung Disease: Lessons from Japan’s Experience: Yukinori K USAKA, et al. Department of Environmental Health, School of Medicine, Fukui Medical University— Metals inducing occupational respiratory diseases, e.g. metal fever, acute and chronic pneumonia, asthma, bronchitis, chronic obstructive lung disease, pulmonary fibrosis and lung cancer are described. The metals mentioned are the following: aluminum, antimony, arsenic, barium, beryllium, cadmium,

Yukinori KUSAKA; Kazuhiro SATO; Narufumi SUGANUMA; Yutaka HOSODA

2001-01-01

92

Modeling three-dimensional constituent particle microstructure and particle-induced pitting corrosion in rolled aluminum alloys  

NASA Astrophysics Data System (ADS)

In the last two decades there has been a surge in research surrounding the corrosion and fatigue properties of high strength aluminum alloys aimed at extending the service life of commercial and military aircraft. It is recognized that corrosion damage in aluminum alloys is the direct result of local galvanic coupling between constituent particles and the metal matrix. As the corrosion pit associated with an individual particle grows it often coalesces with adjacent pits and can expose subsurface constituent particles, perpetuating the evolution of corrosion damage. As a result, heavily clustered groups of constituent particles tend to foster the most severe corrosion pits, and the morphology of these multi-particle pits has been found to exhibit a strong correlation with that of the instigating particle cluster. Severe pits are particularly detrimental to the fatigue life of aluminum components, nucleating fatigue cracks and circumventing the low growth rates of the short crack regime. The goal of this work is to provide a tool for predicting the evolution of particle-induced corrosion damage in rolled aluminum alloys by way of numerical simulation techniques. A three-dimensional constituent particle microstructure model is proposed. This model is used to generate statistically representative three-dimensional constituent particle microstructure from two-dimensional, orthogonal sections. The temporal evolution of severe corrosion damage for a particular constituent particle microstructure can then be simulated via a particle-based corrosion model. This corrosion simulation algorithm makes it possible to perform material-specific, numerical corrosion analyses and represents a significant advancement in the quest to develop reliable and cost efficient life-cycle prediction methods for aging airframes.

Cullin, Matthew Joseph

93

Biological effects induced by nanosilver particles: in vivo study.  

PubMed

Nanosilver particles and microsilver particles were implanted into a rat's back muscle. The pathology and the local biocompatibility were observed and compared at days 7, 14, 30, 90 and 180 after implantation. A good biological effect was observed on days 7 and 14, both in rats treated with nanosilver particles and in rats treated with microsilver particles. A bad biological effect was observed at day 30, and the nanosilver-treated rats had more serious inflammation than the microsilver-treated rats. PMID:18458456

Chen, Dandan; Xi, Tingfei; Bai, Jing

2007-07-30

94

Turbulence-induced Relative Velocity of Dust Particles. I. Identical Particles  

NASA Astrophysics Data System (ADS)

We study the relative velocity of inertial particles suspended in turbulent flows and discuss implications for dust particle collisions in protoplanetary disks. We simulate a weakly compressible turbulent flow, evolving 14 particle species with friction timescale, ?p, covering the entire range of scales in the flow. The particle Stokes numbers, St, measuring the ratio of ?p to the Kolmogorov timescale, are in the range 0.1 <~ St <~ 800. Using simulation results, we show that the model by Pan & Padoan gives satisfactory predictions for the rms relative velocity between identical particles. The probability distribution function (PDF) of the relative velocity is found to be highly non-Gaussian. The PDF tails are well described by a 4/3 stretched exponential function for particles with ?p ~= 1-2 T L, where T L is the Lagrangian correlation timescale, consistent with a prediction based on PP10. The PDF approaches Gaussian only for very large particles with ?p >~ 54 T L. We split particle pairs at given distances into two types with low and high relative speeds, referred to as continuous and caustic types, respectively, and compute their contributions to the collision kernel. Although amplified by the effect of clustering, the continuous contribution vanishes in the limit of infinitesimal particle distance, where the caustic contribution dominates. The caustic kernel per unit cross section rises rapidly as St increases toward ~= 1, reaches a maximum at ?p ~= 2 T L, and decreases as \\tau _p^{-1/2} for ?p Gt T L.

Pan, Liubin; Padoan, Paolo

2013-10-01

95

ULTRAFINE CARBON PARTICLES INDUCE IL-8 EXPRESSION IN HUMAN AIRWAY EPITHELIAL CELLS THROUGH A POST-TRANSCRIPTIONAL MECHANISM  

EPA Science Inventory

Ultrafine carbon particles induce IL-8 expression in human airway epithelial cells through a post-transcritpional mechanism Epidemiological studies suggest that ultrafine particles contribute to particulate matter (PM) - induced adverse health effects. IL-8 is an i...

96

Influence of soot aggregate structure on particle sizing using laser-induced incandescence: importance of bridging between primary particles  

NASA Astrophysics Data System (ADS)

Soot aggregates formed in combustion processes are often described as clusters of carbonaceous particles in random fractal structures. For theoretical studies of the physical properties of such aggregates, they have often been modelled as spherical primary particles in point contact. However, transmission electron microscopy (TEM) images show that the primary particles are more connected than in a single point; there is a certain amount of bridging between the primary particles. Particle sizing using the diagnostic technique laser-induced incandescence (LII) is crucially dependent on the heat conduction rate from the aggregate to the ambient gas, which depends on the amount of bridging. In this work, aggregates with bridging are modelled using overlapping spheres, and it is shown how such aggregates can be built to fulfil specific fractal parameters. Aggregates with and without bridging are constructed numerically, and it is investigated how the bridging influences the heat conduction rate in the free-molecular regime. The calculated heat conduction rates are then used in an LII model to show how LII particle sizing is influenced by different amounts of bridging. For realistic amounts of bridging (), the primary particle diameters were overestimated by up to 9 % if bridging was not taken into account.

Johnsson, J.; Bladh, H.; Olofsson, N.-E.; Bengtsson, P.-E.

2013-09-01

97

A model to evaluate the biological effect induced by the emitted particles from a beta-delayed particle decay beam  

NASA Astrophysics Data System (ADS)

Due to their favourable properties such as high dose localization and high RBE heavy-ion beams have attracted increasing interest in cancer treatment. Efforts to exploit these advantages to the maximum extent in cancer therapy have never been given up. A new idea of applying a radioactive ion beam with beta-delayed particle decay such as 9C or 8B to cancer therapy is put forward in this paper. A model to evaluate the biological effect in terms of cell survival induced by the emitted particles from the decays of the stopped ions has been established. Because of the difference of the internally emitted particle irradiation from the external ion beam, the microdosimetric quantity such as specific energy is applied to evaluate the cell surviving effect induced by the emitted particles from the decays of the radioactive ions. Within the framework of this model, the cell-killing effects resulting from the emitted particles were calculated under different conditions. Finally, the potential application of the radioactive ion beam 9C in cancer therapy is demonstrated.

Li, Qiang; Kanai, Tatsuaki; Kitagawa, Atsushi

2003-09-01

98

Adenovirus Particles that Display the Plasmodium falciparum Circumsporozoite Protein NANP Repeat Induce Sporozoite-Neutralizing Antibodies in Mice  

PubMed Central

Adenovirus particles can be engineered to display exogenous peptides on their surfaces by modification of viral capsid proteins, and particles that display pathogen-derived peptides can induce protective immunity. We constructed viable recombinant adenoviruses that display B-cell epitopes from the Plasmodium falciparum circumsporozoite protein (PfCSP) in the major adenovirus capsid protein, hexon. Recombinants induced high-titer antibodies against CSP when injected intraperitoneally into mice. Serum obtained from immunized mice recognized both recombinant PfCSP protein and P. falciparum sporozoites, and neutralized P. falciparum sporozoites in vitro. Replicating adenovirus vaccines have provided economical protection against adenovirus disease for over three decades. The recombinants described here may provide a path to an affordable malaria vaccine in the developing world.

Palma, Christopher; Overstreet, Michael G.; Guedon, Jean-Marc; Hoiczyk, Egbert; Ward, Cameron; Karen, Kasey A.; Zavala, Fidel; Ketner, Gary

2011-01-01

99

Disease control by sulphur induced resistance  

Microsoft Academic Search

Summary As early as the 19th century, Justus von Liebig (1803 - 1873) identifi ed the lack of vitality of soils and non-existent vigour of plants as relevant causes of increased infections of crops by fungal diseases. Organic farming requires alternative strategies for combating pests and diseases. Soil-applied sulphate fertilisation proved to signifi cantly reduce infection rate and severity of

S HANEKLAUS; E BLOEM; E SCHNUG

100

Occupational lung disease induced by reactive chemicals  

Microsoft Academic Search

In industry, a wide variety of reactive chemicals are employed that can cause respiratory disease in exposed workers) As an example, two general classes of chemicals that cause occupational lung disease in the plastic industry include the anhydrides and the isocyanates. Phthalic anhydride has been a known cause of asthma since the late 1930s. ~ The isocyanates have been known

C. R. Zeiss

1985-01-01

101

Depletion-induced biaxial nematic states of boardlike particles.  

PubMed

With the aim of investigating the stability conditions of biaxial nematic liquid crystals, we study the effect of adding a non-adsorbing ideal depletant on the phase behavior of colloidal hard boardlike particles. We take into account the presence of the depletant by introducing an effective depletion attraction between a pair of boardlike particles. At fixed depletant fugacity, the stable liquid-crystal phase is determined through a mean-field theory with restricted orientations. Interestingly, we predict that for slightly elongated boardlike particles a critical depletant density exists, where the system undergoes a direct transition from an isotropic liquid to a biaxial nematic phase. As a consequence, by tuning the depletant density, an easy experimental control parameter, one can stabilize states of high biaxial nematic order even when these states are unstable for pure systems of boardlike particles. PMID:22739023

Belli, S; Dijkstra, M; van Roij, R

2012-06-27

102

Depletion-induced biaxial nematic states of boardlike particles  

NASA Astrophysics Data System (ADS)

With the aim of investigating the stability conditions of biaxial nematic liquid crystals, we study the effect of adding a non-adsorbing ideal depletant on the phase behavior of colloidal hard boardlike particles. We take into account the presence of the depletant by introducing an effective depletion attraction between a pair of boardlike particles. At fixed depletant fugacity, the stable liquid-crystal phase is determined through a mean-field theory with restricted orientations. Interestingly, we predict that for slightly elongated boardlike particles a critical depletant density exists, where the system undergoes a direct transition from an isotropic liquid to a biaxial nematic phase. As a consequence, by tuning the depletant density, an easy experimental control parameter, one can stabilize states of high biaxial nematic order even when these states are unstable for pure systems of boardlike particles.

Belli, S.; Dijkstra, M.; van Roij, R.

2012-07-01

103

Laser Induced Autoresoance Acceleration of Charged Particle In Vacuum  

NASA Astrophysics Data System (ADS)

The exact relativistic dynamics of a charged particle acted upon the electromagnetic fields of a finite duration laser pulse of arbitrary pulse length, in the presence of a static axial magnetic field, is derived. From the solutions it is demonstrated that the particles with different energies can be obtained by tuning the cyclotron frequency of particle with characteristic frequencies determined by the frequency spectra of the laser pulse. The energy gain of the particle may be further improved by subjecting it to the focused field of the laser pulse in an external magnetic field. The focused field of the laser pulse is simply modeled by slow spatial modulation of the laser intensity along the direction of the laser propagation.

Sagar, Vikram; Sengupta, Sudip; Kaw, Predhiman

2012-10-01

104

Aging induced changes on NEXAFS fingerprints in individual combustion particles  

NASA Astrophysics Data System (ADS)

Soot particles can significantly influence the Earth's climate by absorbing and scattering solar radiation as well as by acting as cloud condensation nuclei. However, despite their environmental (as well as economic and political) importance, the way these properties are affected by atmospheric processing of the combustion exhaust gases is still a subject of discussion. In this work, individual soot particles emitted from two different vehicles, a EURO 2 transporter, a EURO 3 passenger car, and a wood stove were investigated on a single-particle basis. The emitted exhaust, including the particulate and the gas phase, was processed in a smog chamber with artificial solar radiation. Single particle specimens of both unprocessed and aged soot were characterized using near edge X-ray absorption fine structure spectroscopy (NEXAFS) and scanning electron microscopy. Comparison of NEXAFS spectra from the unprocessed particles and those resulting from exhaust photooxidation in the chamber revealed changes in the carbon functional group content. For the wood stove emissions, these changes were minor, related to the relatively mild oxidation conditions. For the EURO 2 transporter emissions, the most apparent change was that of carboxylic carbon from oxidized organic compounds condensing on the primary soot particles. For the EURO 3 car emissions oxidation of primary soot particles upon photochemical aging has likely contributed as well. Overall, the changes in the NEXAFS fingerprints were in qualitative agreement with data from an aerosol mass spectrometer. Furthermore, by taking full advantage of our in situ microreactor concept, we show that the soot particles from all three combustion sources changed their ability to take up water under humid conditions upon photochemical aging of the exhaust. Due to the selectivity and sensitivity of the NEXAFS technique for the water mass, also small amounts of water taken up into the internal voids of agglomerated particles could be detected. Because such small amounts of water uptake do not lead to measurable changes in particle diameter, it may remain beyond the limits of volume growth measurements, especially for larger agglomerated particles.

Zelenay, V.; Mooser, R.; Tritscher, T.; K?epelová, A.; Heringa, M. F.; Chirico, R.; Prévôt, A. S. H.; Weingartner, E.; Baltensperger, U.; Dommen, J.; Watts, B.; Raabe, J.; Huthwelker, T.; Ammann, M.

2011-11-01

105

Human-Induced Particle ReSuspension in a Room  

Microsoft Academic Search

A large-eddy simulation\\/immersed boundary method for particulate flows in an Eulerian framework is utilized to investigate short-term particle re-suspension due to human motion. The simulations involve a human walking through a room, stopping, and then walking in place, causing particles to be re-suspended from a carpet. The carpet layer is modeled as the porous medium and a classical adhesive force

Roshan C. Oberoi; Jung-Il Choi; Jack R. Edwards; Jacky A. Rosati; Jonathan Thornburg; Charles E. Rodes

2010-01-01

106

Treatment of Bacterial Induced Diseases Using DNA Methyl Transferase Inhibitors.  

National Technical Information Service (NTIS)

Methods for treating and/or preventing disease conditions caused or induced or aggravated by microbes, especially bacteria, by inhibiting DNA methyltransferase activity, such as by administering to an animal a DNA methyltransferase inhibitor, are disclose...

C. Stephens L. Shapiro L. S. Kahng R. Wright S. J. Benkovic

2003-01-01

107

Continuous-flow particle and cell separations in a serpentine microchannel via curvature-induced dielectrophoresis  

Microsoft Academic Search

Particle and cell separations are critical to chemical and biomedical analyses. This study demonstrates a continuous-flow\\u000a electrokinetic separation of particles and cells in a serpentine microchannel through curvature-induced dielectrophoresis.\\u000a The separation arises from the particle size-dependent cross-stream dielectrophoretic deflection that is generated by the\\u000a inherent electric field gradients within channel turns. Through the use of a sheath flow to focus

Junjie Zhu; Robert Cameron Canter; Gyunay Keten; Pallavi Vedantam; Tzuen-Rong J. Tzeng; Xiangchun Xuan

108

Morphological characterization of suspended particles under wind-induced disturbance in Taihu Lake, China  

Microsoft Academic Search

Sediments are disturbed by wind frequently, especially in the shallow lakes. The characteristics of resuspended sediment particles\\u000a in Taihu Lake were studied under different wind velocities. It showed that sediment particles suspended obviously and particle\\u000a number in overlying water increased directly under high wind-induced disturbance. Suspended solid (SS) concentration was less\\u000a than 50 mg\\/l when the wind velocity was below

Tao Li; Dongsheng Wang; Bin Zhang; Huijuan Liu; Hongxiao Tang

2007-01-01

109

Particle-induced damage and subsequent healing of materials: Erosion, corrosion and self-healing coatings  

Microsoft Academic Search

This review summarizes research on particle-induced damage and the subsequent repair of metallic materials. Metallic materials are damaged by solid particle impact via two damage processes: repeated plastic deformation and cutting. At a certain low-impact velocity, the particle does not skid, resulting in only plastic deformation with no damage by cutting. The critical impact velocity has been theoretically derived. Self-healing

Akihiro Yabuki

2011-01-01

110

Alpha particle destabilization of the toroidicity-induced Alfve´n eigenmodes  

Microsoft Academic Search

The high-frequency, low mode number toroidicity-induced Alfve´n eigenmodes (TAE) [Phys. Fluids 29, 3695 (1986)] are shown to be driven unstable by the circulating and\\/or trapped ? particles through the wave–particle resonances. Satisfying the resonance condition requires that the ?-particle birth speed v??vA\\/2‖m?nq‖, where vA is the Alfve´n speed, m is the poloidal mode number, and n is the toroidal mode

C. Z. Cheng

1991-01-01

111

DIESEL EXHAUST PARTICLES INDUCE ABERRANT ALVEOLAR EPITHELIAL DIRECTED CELL MOVEMENT BY DISRUPTION OF POLARITY MECHANISMS  

EPA Science Inventory

Disruption of the respiratory epithelium contributes to the progression of a variety of respiratory diseases that are aggravated by exposure to air pollutants, specifically traffic-based pollutants such as diesel exhaust particles (DEP). Recognizing that lung repair following inj...

112

Particle-Induced X-Ray Emission Analysis of Atmospheric Aerosols  

Microsoft Academic Search

We are developing a research program in ion-beam analysis (IBA) of atmospheric aerosols at the Union College Ion-Beam Analysis Laboratory to study the transport, transformation, and effects of airborne pollution in Upstate New York. The simultaneous applications of the IBA techniques of particle-induced X-ray emission (PIXE), Rutherford back-scattering spectrometry (RBS), particle-induced gamma-ray emission (PIGE), and proton elastic scattering analysis (PESA)

Colin Gleason; Charles Harrington; Katie Schuff; Maria Battaglia; Robert Moore; Colin Turley; Michael Vineyard; Scott Labrake

2010-01-01

113

The Role of TLR and Chemokine in Wear Particle-Induced Aseptic Loosening  

PubMed Central

Wear particle-induced periprosthetic osteolysis remains the principal cause of aseptic loosening of orthopaedic implants. Monocytes/macrophages phagocytose wear particles and release cytokines that induce inflammatory response. This response promotes osteoclast differentiation and osteolysis. The precise mechanisms by which wear particles are recognized and induce the accumulation of inflammatory cells in the periprosthetic tissue have not been fully elucidated. Recent studies have shown that toll-like receptors (TLRs) contribute to the cellular interaction with wear particles. Wear particles are recognized by monocytes/macrophages through TLRs coupled with the adaptor protein MyD88. After the initial interaction, wear particles induce both local and systemic migration of monocytes/macrophages to the periprosthetic region. The cellular migration is mediated through chemokines including interleukin-8, macrophage chemotactic protein-1, and macrophage inhibitory protein-1 in the periprosthetic tissues. Interfering with chemokine-receptor axis can inhibit cellular migration and inflammatory response. This paper highlights recent advances in TLR, and chemokine participated in the pathogenesis of aseptic loosening. A comprehensive understanding of the recognition and migration mechanism is critical to the development of measures that prevent wear particle-induced aseptic loosening of orthopaedic implants.

Gu, Qiaoli; Shi, Qin; Yang, Huilin

2012-01-01

114

PAHs, PAH-induced carcinogenic potency, and particle-extract-Induced cytotoxicity of traffic-related nano/ultrafine particles.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) bound in nano/ ultrafine particles from vehicle emissions may cause adverse health effects. However, little is known about the characteristics of the nanoparticle-bound PAHs and the PAH-associated carcinogenic potency/cytotoxicity; therefore, traffic-related nano/ultrafine particles were collected in this study using a microorifice uniform deposition impactor(MOUDI) and a nano-MOUDI. For PM0.056--18, the difference in size-distribution of particulate total-PAHs between non-after-rain and after-rain samples was statistically significant at alpha = 0.05; however, this difference was not significant for PM0.01--0.056. The PAH correlation between PM0.01--0.1 and PM0.1--1.8 was lower for the after-rain samples than forthe non-after-rain samples. The average particulate total-PAHs in five samplings displayed a trimodal distribution with a major peak in the Aitken mode (0.032--0.056 microm). About half of the particulate total-PAHs were in the ultrafine size range. The BaPeq sums of BaP, IND, and DBA (with toxic equivalence factors > or = 0.1) accounted for approximately 90% of the total-BaPeq in the nano/ultrafine particles, although these three compounds contributed little to the mass of the sampled particles. The mean content of the particle-bound total-PAHs/-BaPeqs and the PAH/BaPeq-derived carcinogenic potency followed the order nano > ultrafine > fine > coarse. For a sunny day sample, the cytotoxicity of particle extracts (using 1:1 (v/v) n-hexane/dichloromethane) was significantly higher (p < 0.05) for the nano (particularly the 10-18 nm)/ultrafine particles than for the coarser particles and bleomycin. Therefore, traffic-related nano and ultrafine particles are possibly cytotoxic. PMID:18589992

Lin, Chih-Chung; Chen, Shui-Jen; Huang, Kuo-Lin; Lee, Wen-Jhy; Lin, Wen-Yinn; Tsai, Jen-Hsiung; Chaung, Hso-Chi

2008-06-01

115

ZETA Potential Induced Particle Generation in SC2 Cleaning  

NASA Astrophysics Data System (ADS)

After etch and photo resist (PR) strip, particle and byproduct removal treatment is inevitable. SC1/SC2 cleaning process is one of the useful wet cleaning processes to remove them. In most cases, the equipment is batch type (25 or 50 wafers dip into bath) in which particles lifted from edge or backside of wafer move into chip easily by the stream of chemical. Especially in the process of film like Si3N4 with high dielectric constant, the particle issue is more serious. Following SC1 cleaning (main chemical is NH4OH), SC2 cleaning (main chemical is HCl) causes particles to be attached to wafer. The lifted particles in SC1 cleaning are attached to wafer strongly by ZETA potential, which is enhanced when the PH of chemical is lower than 4 (PH of SC2 chemical is about 1.3). SC2 cleaning after SC1 cleaning is not desirable process sequence. But, SC2 chemical is useful for removing metal contamination generated in etch equipment during the etch process. Skipping SC2 cleaning is desirable in the process which metal contamination has no impact on. But, if you want to use SC2 cleaning or other acid chemical (PH below 4) for a guarantee of quality of device, it should be processed before SC1 cleaning.

Mun, Seong Yeol; Yoon, Ki Chae; An, Byeong Woo

2002-12-01

116

Drift-induced Perpendicular Transport of Solar Energetic Particles  

NASA Astrophysics Data System (ADS)

Drifts are known to play a role in galactic cosmic ray transport within the heliosphere and are a standard component of cosmic ray propagation models. However, the current paradigm of solar energetic particle (SEP) propagation holds the effects of drifts to be negligible, and they are not accounted for in most current SEP modeling efforts. We present full-orbit test particle simulations of SEP propagation in a Parker spiral interplanetary magnetic field (IMF), which demonstrate that high-energy particle drifts cause significant asymmetric propagation perpendicular to the IMF. Thus in many cases the assumption of field-aligned propagation of SEPs may not be valid. We show that SEP drifts have dependencies on energy, heliographic latitude, and charge-to-mass ratio that are capable of transporting energetic particles perpendicular to the field over significant distances within interplanetary space, e.g., protons of initial energy 100 MeV propagate distances across the field on the order of 1 AU, over timescales typical of a gradual SEP event. Our results demonstrate the need for current models of SEP events to include the effects of particle drift. We show that the drift is considerably stronger for heavy ion SEPs due to their larger mass-to-charge ratio. This paradigm shift has important consequences for the modeling of SEP events and is crucial to the understanding and interpretation of in situ observations.

Marsh, M. S.; Dalla, S.; Kelly, J.; Laitinen, T.

2013-09-01

117

The crucial role of particle surface reactivity in respirable quartz-induced reactive oxygen\\/nitrogen species formation and APE\\/Ref1 induction in rat lung  

Microsoft Academic Search

Persistent inflammation and associated excessive oxidative stress have been crucially implicated in quartz-induced pulmonary diseases, including fibrosis and cancer. We have investigated the significance of the particle surface reactivity of respirable quartz dust in relation to the in vivo generation of reactive oxygen and nitrogen species (ROS\\/RNS) and the associated induction of oxidative stress responses in the lung. Therefore, rats

Catrin Albrecht; Ad M Knaapen; Andrea Becker; Doris Höhr; Petra Haberzettl; Frederik J van Schooten; Paul JA Borm; Roel PF Schins

2005-01-01

118

Food-Induced Immune Responses as Origin of Bowel Disease?  

Microsoft Academic Search

Food-induced immune responses cause or influence a number of intestinal diseases. Food antigens may either directly affect the mucosal immune system, or food modulate the intestinal flora, which may alter the immune response. The system preventing food-induced immune responses is complex: The mucosal barrier is the primary mechanism of host defense. Secondly, the innate immune system can neutralize some of

Frank Seibold

2005-01-01

119

Drug-Induced Nephrotoxicity in Inflammatory Bowel Disease  

Microsoft Academic Search

Conservative management of inflammatory bowel disease (IBD) is based on a combination of drugs, including aminosalicylates (ASAs), steroids, antibiotics, immunosuppressives and biologic agents. Although various side effects have been related to treatment regimens, drug-induced nephrotoxicity is rather uncommon. Furthermore, it is often underestimated since renal function deterioration may be attributed to the underlying disease. The nephrotoxicity of ASAs and cyclosporine

Konstantinos A. Oikonomou; Andreas N. Kapsoritakis; Ioannis Stefanidis; Spyros P. Potamianos

2011-01-01

120

INDUCIBLE PLANT DEFENSES: PROSPECTS FOR DISEASE AND STRESS CONTROL  

Technology Transfer Automated Retrieval System (TEKTRAN)

One approach to improve disease resistance in plants and reduce pesticide usage is to take advantage of the plant's inducible defenses. These defenses can be activated by spraying with compounds such as salicylic acid and are an environmentally friendly means of disease control. Although there are...

121

COMPUTATIONAL VASCULAR MORPHOMETRY FOR THE ASSESSMENT OF PULMONARY VASCULAR DISEASE BASED ON SCALE-SPACE PARTICLES  

PubMed Central

We present a fully automatic computational vascular morphometry (CVM) approach for the clinical assessment of pulmonary vascular disease (PVD). The approach is based on the automatic extraction of the lung intraparenchymal vasculature using scale-space particles. Based on the detected features, we developed a set of image-based biomarkers for the assessment of the disease using the vessel radii estimation provided by the particle’s scale. The biomarkers are based on the interrelation between vessel cross-section area and blood volume. We validate our vascular extraction method using simulated data with different complexity and we present results in 2,500 CT scans with different degrees of chronic obstructive pulmonary disease (COPD) severity. Results indicate that our CVM pipeline may track vascular remodeling present in COPD and it can be used in further clinical studies to assess the involvement of PVD in patient populations.

Estepar, Raul San Jose; Ross, James C.; Krissian, Karl; Schultz, Thomas; Washko, George R.; Kindlmann, Gordon L.

2013-01-01

122

TLR4 contributes to disease-inducing mechanisms resulting in central nervous system autoimmune disease.  

PubMed

Environmental factors strongly influence the development of autoimmune diseases, including multiple sclerosis. Despite this clear association, the mechanisms through which environment mediates its effects on disease are poorly understood. Pertussis toxin (PTX) functions as a surrogate for environmental factors to induce animal models of autoimmunity, such as experimental autoimmune encephalomyelitis. Although very little is known about the molecular mechanisms behind its function in disease development, PTX has been hypothesized to facilitate immune cell entry to the CNS by increasing permeability across the blood-brain barrier. Using intravital microscopy of the murine cerebromicrovasculature, we demonstrate that PTX alone induces the recruitment of leukocytes and of active T cells to the CNS. P-selectin expression was induced by PTX, and leukocyte/endothelial interactions could be blocked with a P-selectin-blocking Ab. P-selectin blockade also prevented PTX-induced increase in permeability across the blood-brain barrier. Therefore, permeability is a secondary result of recruitment, rather than the primary mechanism by which PTX induces disease. Most importantly, we show that PTX induces intracellular signals through TLR4, a receptor intimately associated with innate immune mechanisms. We demonstrate that PTX-induced leukocyte recruitment is dependent on TLR4 and give evidence that the disease-inducing mechanisms initiated by PTX are also at least partly dependent on TLR4. We propose that this innate immune pathway is a novel mechanism through which environment can initiate autoimmune disease of the CNS. PMID:15557205

Kerfoot, Steven M; Long, Elizabeth M; Hickey, Michael J; Andonegui, Graciela; Lapointe, Benoit M; Zanardo, Renata C O; Bonder, Claudine; James, Will G; Robbins, Stephen M; Kubes, Paul

2004-12-01

123

Virus-like particles associated with banana bunchy top disease contain small single-stranded DNA.  

PubMed

Virus-like particles were purified from banana plants with banana bunchy top disease. These particles were isometric with a diameter of 18 to 20 nm and a density of 1.28 to 1.30 g/ml in caesium sulphate. Associated with these particles were an ssDNA of about 1 kb and one major protein of Mr 20,100. DsDNA was synthesized from nucleic acid extracts from these particles and cloned. One clone, pBT338, hybridized specifically (i) with sap extracts from plants infected with banana bunchy top virus (BBTV) but not with sap extracts from healthy plants and (ii) with the small ssDNA in nucleic acid extracts from infected plants and virus-like particles. Banana bunchy top disease was transmitted from infected to healthy bananas by aphid inoculation and it was demonstrated that the small ssDNA was transmitted with the disease. It is probable that these particles represent the virions of BBTV containing small ssDNA and that the virus resembles subterranean clover stunt virus more than any other known virus. PMID:1993864

Harding, R M; Burns, T M; Dale, J L

1991-02-01

124

Buckling-induced jamming in channel flow of particle rafts  

NASA Astrophysics Data System (ADS)

We report on observations of the flow of plastic particles floating on the surface of water in a rectangular channel. The system is driven by moving one wall of the channel at a constant velocity. The opposite side of the channel is open, and the particles are pushed into a region free of material. During the flow, video of the particle motions is captured, and the average force on the pushing wall is measured. We have studied particle shapes that are both circular disks and rectangular bars. We find that when the rectangular bars form a layer at the side walls of the channel (whether or not the central region is filled with disks or additional rectangular bars), the system exhibits sudden increases and decreases in the average force on the driving wall. This behavior is consistent with the existence of jamming in the system. We report on the shape and velocity dependence of these force fluctuations, and the evidence that buckling of the rectangular blocks at the wall is responsible for generating the jamming dynamics.

Kuo, Chin-Chang; Dennin, Michael

2013-03-01

125

A self-consistent theory of collective alpha particle losses induced by Alfvenic turbulence  

SciTech Connect

The nonlinear dynamics of kinetic Alfven waves, resonantly excited by energetic ions/alpha particles, is investigated. It is shown that {alpha}-particles govern both linear instability and nonlinear saturation dynamics, while the background MHD turbulence results only in a nonlinear real frequency shift. The most efficient saturation mechanism is found to be self-induced profile modification. Expressions for the fluctuation amplitudes and the {alpha}-particle radial flux are self-consistently derived. The work represents the first self-consistent, turbulent treatment of collective {alpha}-particle losses by Alfvenic fluctuations.

Biglari, H. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Diamond, P.H. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics

1992-01-01

126

Necrosis of HepG2 cancer cells induced by the vibration of magnetic particles  

NASA Astrophysics Data System (ADS)

Experiments of magnetolysis, i.e., destruction of cells induced with magnetic particles (MPs) submitted to the application of a magnetic field, were conducted on HepG2 cancer cells. We herein demonstrate the usefulness of combining anisotropic MPs with an alternative magnetic field in magnetolysis. Thus, the application of an alternative magnetic field of low frequency (a few Hertz) in the presence of anisotropic, submicronic particles allowed the destruction of cancer cells "in vitro". We also show that a constant magnetic field is far less efficient than an oscillating one. Moreover, we demonstrate that, at equal particle volume, it is much more efficient to utilize spindle shaped particles rather than spherical ones. In order to get deeper insight into the mechanism of magnetolysis experiments, we performed a study by AFM, which strongly supports that the magnetic field induces the formation of clusters of particles becoming then large enough todamage cell membranes.

Wang, Biran; Bienvenu, Céline; Mendez-Garza, Juan; Lançon, Pascal; Madeira, Alexandra; Vierling, Pierre; Di Giorgio, Christophe; Bossis, Georges

2013-10-01

127

Chloroquine-induced lipidosis mimicking Fabry disease  

Microsoft Academic Search

Intracellular accumulation of phospholipids may be a consequence of inherited or acquired metabolic disorders. In Fabry disease, deficiency of ?-galactosidase A results in storage of globotriasylceramide in numerous cells including endothelium, striated muscle (skeletal, cardiac), smooth muscle, and renal epithelium among others; the ultrastructural appearance of the inclusions is of whorled layers of alternating dense and pale material (‘zebra bodies’

Diana Albay; Sharon G Adler; Jaya Philipose; C C Calescibetta; Stephen G Romansky; Arthur H Cohen

2005-01-01

128

Motion and twisting of magnetic particles ingested by alveolar macrophages in the human lung: effect of smoking and disease  

PubMed Central

Background Magnetic microparticles being ingested by alveolar macrophages can be used as a monitor for intracellular phagosome motions and cytoskeletal mechanical properties. These studies can be performed in the human lung after voluntary inhalation. The influence of cigarette smoking and lung diseases on cytoskeleton dependent functions was studied. Methods Spherical 1.3 ?m diameter ferrimagnetic iron oxide particles were inhaled by 17 healthy volunteers (40 – 65 years), 15 patients with sarcoidosis (SAR), 12 patients with idiopathic pulmonary fibrosis (IPF), and 18 patients with chronic obstructive bronchitis (COB). The retained particles were magnetized and aligned in an external 100 mT magnetic field. All magnetized particles induce a weak magnetic field of the lung, which was detected by a sensitive SQUID (superconducting quantum interference device) sensor. Cytoskeletal reorganizations within macrophages and intracellular transport cause stochastic magnetic dipole rotations, which are reflected in a decay of the magnetic lung field, called relaxation. Directed phagosome motion was induced in a weak magnetic twisting field. The resistance of the cytoplasm to particle twisting was characterized by the viscosity and the stiffness (ratio between stress to strain) of the cytoskeleton. Results One week after particle inhalation and later macrophage motility (relaxation) and cytoskeletal stiffness was not influenced by cigarette smoking, neither in healthy subjects, nor in the patients. Patients with IPF showed in tendency a faster relaxation (p = 0.06). Particle twisting revealed a non-Newtonian viscosity with a pure viscous and a viscoelastic compartment. The viscous shear was dominant, and only 27% of the shear recoiled and reflected viscoelastic properties. In patients with IPF, the stiffness was reduced by 60% (p < 0.02). An analysis of the shear rate and stress dependence of particle twisting allows correlating the rheological compartments to cytoskeletal subunits, in which microtubules mediate the pure viscous (non-recoverable) shear and microfilaments mediate the viscoelastic (recoverable) behavior. The missing correlation between relaxation and particle twisting shows that both stochastic and directed phagosome motion reflect different cytoskeletal mechanisms. Conclusion Faster relaxation and a soft cytoskeleton in patients with IPF indicate alterations in cytoskeleton dependent functions of alveolar macrophages, which may cause dysfunction's in the alveolar defense, like a slower migration, a retarded phagocytosis, a disturbed phagosome lysosome fusion and an impaired clearance.

Moller, Winfried; Barth, Winfried; Kohlhaufl, Martin; Haussinger, Karl; Kreyling, Wolfgang G

2006-01-01

129

Management of drug-induced liver disease  

Microsoft Academic Search

The treatment and prevention of drug-induced liver injury starts with the recognition of hepatotoxicity at the earliest possible\\u000a time so that the suspected drug can be discontinued expeditiously. Both liver enzyme monitoring and vigilance for signs of\\u000a hypersensitivity involving the liver are useful strategies for many agents known to cause hepatocellular necrosis leading\\u000a to liver failure. Specific antidotes to prevent

Gustavo Marino; Hyman J. Zimmerman; James H. Lewis

2001-01-01

130

Rotavirus Virus-Like Particles Administered Mucosally Induce Protective Immunity  

Microsoft Academic Search

We have evaluated the immunogenicity and protective efficacy of rotavirus subunit vaccines administered by mucosal routes. Virus-like particles (VLPs) produced by self-assembly of individual rotavirus structural proteins coexpressed by baculovirus recombinants in insect cells were the subunit vaccine tested. We first compared the immunogenicities and protective efficacies of VLPs containing VP2 and VP6 (2\\/6-VLPs) and G3 2\\/6\\/7-VLPs mixed with cholera

CHRISTINE M. O'NEAL; SUE E. CRAWFORD; MARY K. ESTES; MARGARET E. CONNER

1997-01-01

131

Particle heating in magnetized plasmas with interpolation-induced divergence  

Microsoft Academic Search

Summary form only given: Numerical effects in particle-in-cell (PIC) simulations due to the interpolation of discrete magnetic fields are examined. Heating, cooling, and\\/or non-physical diffusion across field lines is a concern for magnetically confinement plasmas in applications such as magnetic confinement fusion, sputtering magnetrons, and many other devices. A classical axisymmetric magnetic-mirror configuration is used to investigate the effects of

M. P. Aldan; J. P. Verboncoeur

2009-01-01

132

Nephrolithiasis-induced end stage renal disease  

PubMed Central

Introduction: Nephrolithiasis still remains a too frequent and underappreciated cause of end stage renal disease (ESRD). Methods and patients: Of the entire cohort of 7128 consecutive patients who started maintenance dialysis in our nephrology department between January 1992 and December 2006, a total of 45 patients (26 women, 19 men) had renal stone disease as the cause of ESRD. The type of nephrolithiasis was determined in 45 cases and etiology in 42. The treatment and evolution of stone disease and patient’s survival were studied. Results: The overall proportion of nephrolithiasis related ESRD was 0.63%. The mean age was 48.4 years. Infection stones (struvite) accounted for 40%, calcium stones, 26.67% (primary hyperparathyroidism:15.56%; familial hypercalciuria: 4.44%, unknown etiology: 6.66%), primary hyperoxaluria type 1, 17.78% and uric acid lithiasis in 15.56% of cases. The mean delay of the evolution of the stone renal disease to chronic renal failure was 85.8 months. The feminine gender, obesity and elevated alkaline phosphatases >128 IU/L were significantly correlated with fast evolution of ESRD. The median evolution to ESRD was 12 months. The normal body mass index (BMI), medical treatment of stone and primary hyperoxaluria type 1 were correlated with fast evolution to ESRD. All patients were treated by hemodialysis during a mean evolution of 60 months. Sixteen patients died. The patient's survival rate at 1, 3 and 5 years was 97.6, 92.8 and 69% respectively. Hypocalcemia, cardiopathy and normal calcium-phosphate product were significantly correlated with lower survival rate. Conclusion: Severe forms of nephrolithiasis remain an underestimated cause of ESRD. These findings highlight the crucial importance of accurate stone analysis and metabolic evaluation to provide early diagnosis and efficient treatment for conditions leading to ESRD.

Ounissi, M; Gargueh, T; Mahfoudhi, M; Boubaker, K; Hedri, H; Goucha, R; Abderrahim, E; Ben Hamida, F; Ben Abdallah, T; El Younsi, F; Ben Maiz, H; Kheder, A

2010-01-01

133

Kinetic arrest in polyion-induced inhomogeneously charged colloidal particle aggregation.  

PubMed

Polymer chains adsorbed onto oppositely charged colloidal particles can significantly modify the particle-particle interactions. For sufficient amounts of added polymers, the original electrostatic repulsion can even turn into an effective attraction and relatively large aggregates can form. The attractive interaction contribution between two particles arises from the correlated adsorption of polyions at the oppositely charged particle surfaces, resulting in a non-homogeneous surface charge distribution. Here, we investigate the aggregation kinetics of polyion-induced colloidal complexes through Monte Carlo simulation, in which the effect of charge anisotropy is taken into account by a DLVO-like inter-particle potential, as recently proposed by Velegol and Thwar (Langmuir 17, 7687 (2001)). The results reveal that the aggregation process slows down due to the progressive increase of the potential barrier height upon clustering. Within this framework, the experimentally observed cluster phases in polyelectrolyte-liposome solutions can be interpreted as a kinetic arrested state. PMID:19551418

Truzzolillo, D; Bordi, F; Sciortino, F; Cametti, C

2009-06-24

134

Comparison of Particle Size Measurements with Laser-Induced Incandescence, Mass Spectroscopy, and Scanning Mobility Particle Sizing in a Laminar Premixed Ethylene\\/Air Flame  

Microsoft Academic Search

Particle size distribution functions (PSDF) and mean particle sizes have been determined in a laminar premixed ethylene\\/air flame with three different experimental approaches: photo-ionization mass spectrometry (PIMS), scanning mobility particle sizing (SMPS), and laser-induced incandescence (LII). The main goal of this investigation was the cross-validation of these three methods used at our institute for the determination of particle sizes in

R. Stirn; T. Gonzalez Baquet; S. Kanjarkar; W. Meier; K. P. Geigle; H. H. Grotheer; C. Wahl; M. Aigner

2009-01-01

135

Particle induced damage on heads and discs due to fine particles of different materials  

Microsoft Academic Search

Fine particles of aluminum, stainless steel, silicon, slider ceramic (Al2O3-TiC) and sputtered alumina were introduced at the head\\/disc interface of hard disc drives. Experiments were conducted with discs made from aluminum and glass substrates. Glass substrates were much harder than aluminum substrates. It was found that the type of damage introduced on the disc and slider was to some extent

Lihong Zhang; Ramesh Koka; Yewwah Yuen; Edwin Lam

1999-01-01

136

Controlling crop diseases using induced resistance: challenges for the future.  

PubMed

A number of different types of induced resistance have been defined based on differences in signalling pathways and spectra of effectiveness, including systemic acquired resistance and induced systemic resistance. Such resistance can be induced in plants by application of a variety of biotic and abiotic agents. The resulting resistance tends to be broad-spectrum and can be long-lasting, but is rarely complete, with most inducing agents reducing disease by between 20 and 85%. Since induced resistance is a host response, its expression under field conditions is likely to be influenced by a number of factors, including the environment, genotype, crop nutrition and the extent to which plants are already induced. Although research in this area has increased over the last few years, our understanding of the impact of these influences on the expression of induced resistance is still poor. There have also been a number of studies in recent years aimed at understanding of how best to use induced resistance in practical crop protection. However, such studies are relatively rare and further research geared towards incorporating induced resistance into disease management programmes, if appropriate, is required. PMID:23386685

Walters, Dale R; Ratsep, Jaan; Havis, Neil D

2013-02-05

137

Wear particles generated from studded tires and pavement induces inflammatory reactions in mouse macrophage cells.  

PubMed

Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. These health risks are of increasing concern in society, and to protect public health, a clarification of the toxic properties of particles from different sources is of importance. Lately, wear particles generated from traffic have been recognized as a major contributing source to the overall particle load, especially in the Nordic countries where studded tires are used. The aim of this study was to further investigate and compare the ability to induce inflammatory mediators of different traffic-related wear particles collected from an urban street, a subway station, and studded tire-pavement wear. Inflammatory effects were measured as induction of nitric oxide (NO), IL-6, TNF-alpha, arachidonic acid (AA), and lipid peroxidation after exposure of the murine macrophage like cell line RAW 264.7. In addition, the redox potential of the particles was measured in a cell-free system. The results show that all particles tested induce IL-6, TNF-alpha, and NO, and those from the urban street were the most potent ones. In contrast, particles collected from a subway station were most potent to induce lipid peroxidation, AA release, and formation of ROS. Particles from studded tire-pavement wear, generated using a road simulator, were able to induce inflammatory cytokines, NO, lipid peroxidation, and ROS formation. Interestingly, particles generated from pavement containing granite as the main stone material were more potent than those generated from pavement containing quartzite as the main stone material. PMID:17516662

Lindbom, John; Gustafsson, Mats; Blomqvist, Göran; Dahl, Andreas; Gudmundsson, Anders; Swietlicki, Erik; Ljungman, Anders G

2007-05-22

138

Preclinical and clinical progress of particle-mediated DNA vaccines for infectious diseases  

Microsoft Academic Search

This review provides an overview of studies employing particle-mediated epidermal delivery (PMED) or the gene gun to administer DNA vaccines for infectious diseases in preclinical studies employing large animal models and in human clinical trials. It reviews the immunogenicity and protective efficacy of PMED DNA vaccines in nonhuman primates and swine and studies that have directly compared the effectiveness of

Deborah H. Fuller; Peter Loudon; Connie Schmaljohn

2006-01-01

139

Transition induced by fixed and freely convecting spherical particles in laminar boundary layers  

NASA Astrophysics Data System (ADS)

An experimental and analytical study of aspects of transition induced by disturbances from spherical particles in laminar boundary layers is discussed. The generation of turbulent wedges by fixed spherical particles in a laminar boundary layer on or near the surface of a flat plate is considered experimentally using flow visualization with fluorescent dye and laser Doppler velocimetry. Turbulent spots generated by freely convecting spherical particles that are released in the freestream to fall into a flat plate laminar boundary layer and impact the plate are also discussed. A combination of dye flow visualization and a video based particle tracking technique was used to study the convecting particle problem. Although the Reynolds number at the critical condition for turbulent wedge generation by fixed particles and turbulent spot generation by convecting particles are similar, transition in these two situations appears to be fundamentally different. The development of a turbulent wedge near the critical condition is a relatively gradual process. In contrast, turbulent spots form relatively quickly after the convecting particles enter the boundary layer and impact the plate. Turbulent wedge formation downstream of a fixed particle results from the destabilization of the near wall flow by the vortical structures shed into particle wake. This shedding process is dominated by periodically shed loop shaped hairpin vortices. Observation of subharmonic oscillations at 1/2 and 1/4 of this shedding frequency suggest that a chaotic route to turbulence by a series of period doubling bifurcations is possible.

Petrie, H. L.; Morris, P. J.; Bajwa, A. R.; Vincent, D. C.

1993-08-01

140

Measurement of Fluorescence Spectra from Ambient Aerosol Particles Using Laser-induced Fluorescence Technique  

NASA Astrophysics Data System (ADS)

To obtain the information of composition of organic aerosol particles in atmosphere, we developed an instrument using laser-induced fluorescence (LIF) technique. To measure the fluorescence from a particle, we employed two lasers. Scattering light signal derived from a single particle upon crossing the 635nm-CW laser triggers the 266nm-pulsed laser to excite the particle. Fluorescence from the particle in the wavelength range 300-600nm is spectrally dispersed by a grating spectrometer and then detected by a 32-Ch photo-multiplier tube(PMT). The aerosol stream is surrounded by a coaxial sheath air flow and delivered to the optical chamber at atmospheric pressure. Using PSL particles with known sizes, we made a calibration curve to estimate particle size from scattering light intensity. With the current setup of the instrument we are able to detect both scattering and fluorescence from particles whose diameters are larger than 0.5um. Our system was able to differentiate particles composed of mono-aromatic species (e.g. Tryptophan) from those of Riboflavin, by their different fluorescence wavelengths. Also, measurements of fluorescence spectra of ambient particles were demonstrated in our campus in Yokosuka city, facing Tokyo bay in Japan. We obtained several types of florescence spectra in the 8 hours. Classification of the measured fluorescence spectra will be discussed in the presentation.

Taketani, F.; Kanaya, Y.; Nakamura, T.; Moteki, N.; Takegawa, N.

2011-12-01

141

Metastatic Carcinoid Disease Inducing Coronary Vasospasm  

PubMed Central

Herein, we report a case of progressive coronary vasospasm in a 70-year-old man who had a long-standing history of metastatic gastrointestinal carcinoid tumor. Despite octreotide, nitrate, and calcium channel-blocker therapy, the patient's urinary 5-hydroxy-indole acetic acid level increased, coinciding with an increased frequency of flushing episodes with chest discomfort. In the cardiac catheterization laboratory, we captured an episode that was associated with diffuse right coronary artery spasm, ST-segment elevation, and intense symptoms. We attribute the patient's coronary vasospasm to his metastatic carcinoid disease.

Eapen, Danny J.; Clements, Stephen; Block, Peter; Sperling, Laurence

2012-01-01

142

Pathogenesis of Chlamydia induced pelvic inflammatory disease  

PubMed Central

Further research is necessary to elucidate the pathogenesis of chlamydial PID. It is hoped that these endeavours will eventually lead to a vaccine to prevent not only chlamydia infection, but also chlamydia associated infertility, ectopic pregnancy, and chronic pelvic pain. In the meantime we need to develop strategies to prevent primary and secondary chlamydia infection and its sequelae. Recently, Scholes et. al demonstrated that a population based approach to identify and test women at high risk for cervical C trachomatis infection effectively reduced risk of PID. Hopefully, through the use of public health measures, we can see similar decreases of chlamydia associated genital tract disease worldwide. ???

Cohen, C. R.; Brunham, R. C.

1999-01-01

143

Collective two-particle resonances induced by photon entanglement  

SciTech Connect

An assembly of noninteracting atoms may become correlated upon interaction with entangled photons, and certain elements of their joint density matrix can then show collective resonances. We explore experimental signatures of these resonances in the nonlinear response of a pair of two-level atoms. We find that these resonances are canceled out in stimulated signals such as pump-probe and two-photon absorption due to the destructive interference of two-photon-absorption and emission pathways in the joint two-particle space. However, they may be observed in photon statistics (Hanbury-Brown-Twiss) measurements through the attenuation of two-time intensity correlations.

Richter, Marten [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States); Institut fuer Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

2011-06-15

144

Pollutant particles induce arginase II in human bronchial epithelial cells  

EPA Science Inventory

Exposure to particulate matter (PM) is associated with adverse pulmonary effects, including induction and exacerbation of asthma. Recently arginase was shown to play an important role in the pathogenesis of asthma. In this study, we hypothesized that PM exposure would induce ar...

145

Correlation of picosecond laser-induced latchup and energetic particle-induced latchup in CMOS test structures  

Microsoft Academic Search

We show that the thresholds for picosecond (psec) laser pulse-induced latchup and energetic particle-induced latchup are well correlated over a range of bulk CMOS test structures designed to be susceptible to latchup. The spatial length of the latchup-sensitive node of the test structures covers a range of values that commonly occur in bulk CMOS devices. The accuracy of this correlation

Steven C. MOSS; Stephen D. LaLumondiere; John R. Scarpulla; Kenneth P. MacWilliams; W. R. Crain; Rocky Koga

1995-01-01

146

Evaluation of particle-induced X-ray emission and particle-induced ?-ray emission of quartz grains for forensic trace sediment analysis.  

PubMed

The independent verification in a forensics context of quartz grain morphological typing by scanning electron microscopy was demonstrated using particle-induced X-ray emission (PIXE) and particle-induced ?-ray emission (PIGE). Surface texture analysis by electron microscopy and high-sensitivity trace element mapping by PIXE and PIGE are independent analytical techniques for identifying the provenance of quartz in sediment samples in forensic investigations. Trace element profiling of the quartz grain matrix separately from the quartz grain inclusions served to differentiate grains of different provenance and indeed went some way toward discriminating between different quartz grain types identified in a single sample of one known forensic provenance. These results confirm the feasibility of independently verifying the provenance of critical samples from forensic cases. PMID:22242935

Bailey, M J; Morgan, R M; Comini, P; Calusi, S; Bull, P A

2012-02-09

147

Chitin particles induce size-dependent but carbohydrate-independent innate eosinophilia  

PubMed Central

Murine M? that phagocytose CMP develop into M1; this response depends on the size and the chemical composition of the particles. In contrast, recent studies concluded that chitin particles induce M2 and eosinophil migration, promoting acquired Th2 immune responses against chitin-containing microbes or allergens. This study examined whether these apparently inconsistent responses to chitin could be induced by variation in the size and chemical composition of the chitin particles. We compared the responses of M? with CMP, LCB, and Sephadex G-100 beads (>40 ?m). Beads were given i.p. to WT mice and to mice deficient in a CRTH2, a receptor for the eosinophil chemoattractant PGD2. In contrast to the M1 activation induced by CMP, i.p. administration of LCB or Sephadex beads induced within 24 h a CRTH2-dependent peritoneal eosinophilia, as well as CRTH2-independent activation of peritoneal M? that expressed Arg I, an M2 phenotype. LCB-induced M? exhibited elevated Arg I and a surface MR, reduced surface TLR2 levels, and no change in the levels of CHI3L1 or IL-10 production. Our results indicate that the effects of chitin in vivo are highly dependent on particle size and that large, nonphagocytosable beads, independent of their chemical composition, induce innate eosinophilia and activate M? expressing several M2, but not M1, phenotypes.

Kogiso, Mari; Nishiyama, Akihito; Shinohara, Tsutomu; Nakamura, Masataka; Mizoguchi, Emiko; Misawa, Yoshinori; Guinet, Elisabeth; Nouri-Shirazi, Mahyar; Dorey, C. Kathleen; Henriksen, Ruth Ann; Shibata, Yoshimi

2011-01-01

148

Severe immunodeficiency disease induced by a defective murine leukaemia virus  

Microsoft Academic Search

DIFFERENT classes of retroviruses have been shown to induce immunodeficiency diseases in various animal species1. These animal models may provide an insight into our understanding of AIDS1-3 but, with the exception of one strain of feline leukaemia virus4, the determinants of pathogenicity have not yet been mapped to these viral genomes. The immunodeficiency-inducing feline leukaemia virus is replication-defective4, harbouring the

Douglas C. Aziz; Zaher Hanna; Paul Jolicoeur

1989-01-01

149

Chronic Subclinical Prion Disease Induced by Low-Dose Inoculum  

Microsoft Academic Search

We have compared the transmission characteristics of the two mouse-adapted scrapie isolates, ME7 and Rocky Mountain Laboratory (RML), in tga20 mice. These mice express elevated levels of PrP protein compared to wild-type mice and display a relatively short disease incubation period following intracerebral prion inoculation. Terminal prion disease in tga20 mice induced by ME7 or RML was characterized by a

Alana M. Thackray; Michael A. Klein; Adriano Aguzzi; Raymond Bujdoso

2002-01-01

150

Sorbent behaviour in circulating fluidized bed combustors: Relevance of thermally induced fractures to particle size dependence  

Microsoft Academic Search

The particle size dependence of the performance of various limestones and dolostones in capturing SO2 in fluidized bed combustors was determined and explained in terms of the occurrence of thermally induced fractures (TIFs). Data were obtained in a bench-scale fluidized bed reactor, a pilot-scale down-fired combustor and a 30 MW(e) circulating fluidized bed combustor (CFBC). Finer particle size fractions (100

Sarma V. Pisupati; Ronald S. Wasco; Joel L. Morrison; Alan W. Scaroni

1996-01-01

151

Particle precipitation induced by short-duration VLF waves in the magnetosphere  

Microsoft Academic Search

An extension of a previous test particle simulation model (Inan et al.,1978) of the gyroresonance wave-particle interaction in the magnetosphere is used to compute the detailed time variation of the precipitated energy flux induced by monochromatic short-duration VLF waves. The resulting precipitation pulse is found to have a characteristic shape dependent on the L value, a cold plasma density wave

T. F. Bell; H. C. Chang

1982-01-01

152

Trapped-Particle Mediated Asym-etry-Induced Damping of Diocotron Modes  

Microsoft Academic Search

The nominally stable electron plasma diocotron modes (kz = 0, m_theta = 1,2,..., frequency f_m) exhibit strong exponential damping (rate gamma_m) when the confinement fields have weak theta- and z-asymmetries. This represents ``trapped-particle-mediated, asymmetry-induced'' damping, due to collisional dissipation at the velocity-space separatrix between axially trapped and sloshing particles. The damping is intimately connected to the concurrent bulk plasma expansion

A. A. Kabantsev; C. F. Driscoll

2004-01-01

153

Preparation of polystyrene latex particles by gamma-rays-induced emulsifier-free emulsion polymerization  

Microsoft Academic Search

Monodisperse polystyrene latex particles were prepared by 60Co-gamma-ray radiation-induced emulsifier-free emulsion polymerization with the use of surfactant monomer at room temperature. The surfactant monomer 10(9)-hydroxyl-9(10)-allyl ether octadecanoic acid (HAEOA) was synthesized and characterized by FT-IR and 1H-NMR spectra. TEM was used to characterize the polystyrene latex particles. HAEOA acted as not only a comonomer but also a stabilizer to copolymerize

Xinbo Wang; Zhicheng Zhang

2006-01-01

154

Solar particle induced upsets in the TDRS-1 attitude control system RAM during the October 1989 solar particle events  

SciTech Connect

The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU`s calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU`s by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU`s. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU`s was 72, yielding a total of 248 predicted SEU`s, very close to the 243 observed SEU`s.

Croley, D.R. [SYSCON Corp., Montrose, CA (United States); Garrett, H.B.; Murphy, G.B. [Jet Propulsion Lab., Pasadena, CA (United States); Garrard, T.L. [California Inst. of Tech., Pasadena, CA (United States). George W. Downs Lab. of Physics

1995-10-01

155

Vibrational Raman studies of particle induced damage in oxide glass  

Microsoft Academic Search

Both bulk and glass fiber samples of NaPOâ Y(POâ)â, and SiOâ were subjected to external 5.5 MeV alpha irradiation in a nitrogen glove box from either ²³⁸Pu or ²⁴⁴Cm sources. Since damage is induced in a ca. 20 ..mu.. surface layer, thin fiber samples were chosen to optimize surface effects. All glasses developed color centers upon irradiation observed in measured

Exarhos

1983-01-01

156

Model of n=0 Energetic Particle Induced Oscillations in JET  

NASA Astrophysics Data System (ADS)

Pronounced n=0 frequency sweeping phenomena has been observed in the JET tokamak experiment during ICRF heating. The observed frequency is below the TAE frequency, typically reduced by the inverse aspect ratio. The mechanism for instabiities leading to frequency sweeping is usually attributed to the universal instability drive from energetic particles coupling with Alfvenic excitations as in the case for TAE instabilities and fishbone oscillations. However, for an n=0 mode, the universal instability mode does not apply and the instability mechanism needs to arise from another source. A theoretical model to explain this observation attributes the basic mode to a radial 'breathing" oscillation and instability drive to the energetic ion anisotropy produced by ICRF heating. Analysis and modelling will be presented. This new model produces mode frequencies that scale properly with changing experimental parameters and the anisotropy drive is comparable with the method of heating where ICRF resonance is on the high field side of the magnetic axis.

Berk, H. L.; Sharapov, S. E.; Nave, M. F.; Pinches, S. D.; Boswell, C.

2004-11-01

157

Particle-induced amorphization of complex ceramics. Final report  

SciTech Connect

The crystalline-to-amorphous (c-a) phase transition is of fundamental importance. Particle irradiations provide an important, highly controlled means of investigating this phase transformation and the structure of the amorphous state. The interaction of heavy-particles with ceramics is complex because these materials have a wide range of structure types, complex compositions, and because chemical bonding is variable. Radiation damage and annealing can produce diverse results, but most commonly, single crystals become aperiodic or break down into a polycrystalline aggregate. The authors continued the studies of the transition from the periodic-to-aperiodic state in natural materials that have been damaged by {alpha}-recoil nuclei in the uranium and thorium decay series and in synthetic, analogous structures. The transition from the periodic to aperiodic state was followed by detailed x-ray diffraction analysis, in-situ irradiation/transmission electron microscopy, high resolution transmission electron microscopy, extended x-ray absorption fine structure spectroscopy/x-ray absorption near edge spectroscopy and other spectroscopic techniques. These studies were completed in conjunction with bulk irradiations that can be completed at Los Alamos National Laboratory or Sandia National Laboratories. Principal questions addressed in this research program included: (1) What is the process at the atomic level by which a ceramic material is transformed into a disordered or aperiodic state? (2) What are the controlling effects of structural topology, bond-type, dose rate, and irradiation temperature on the final state of the irradiated material? (3) What is the structure of the damaged material? (4) What are the mechanisms and kinetics for the annealing of interstitial and aggregate defects in these irradiated ceramic materials? (5) What general criteria may be applied to the prediction of amorphization in complex ceramics?

Ewing, R.C.; Wang, L.M.

1998-08-01

158

Management of drug-induced liver disease.  

PubMed

The treatment and prevention of drug-induced liver injury starts with the recognition of hepatotoxicity at the earliest possible time so that the suspected drug can be discontinued expeditiously. Both liver enzyme monitoring and vigilance for signs of hypersensitivity involving the liver are useful strategies for many agents known to cause hepatocellular necrosis leading to liver failure. Specific antidotes to prevent or limit hepatic damage exist for only a few drugs, the most important being N-acetylcysteine for the treatment of acetaminophen hepatotoxicity. Corticosteroids are of unproven benefit in the setting of fulminant failure. Ursodiol may be helpful in instances of cholestatic injury. For other agents, supportive measures and the increasing use of liver-assist devices as well as emergency liver transplantation are available when drug injury evolves into irreversible liver failure. It is hoped that a better understanding of hepatotoxicity mechanisms will lead to the development of more specific and effective forms of therapy in the near future. PMID:11177693

Marino, G; Zimmerman, H J; Lewis, J H

2001-02-01

159

[Chronic peripheral arterial disease induced by cocaine].  

PubMed

Cocaine induced acute peripheral thrombosis, though a rare complication, has been described in the literature. Although there are reports describing the chronic effects of cocaine on the peripheral arterial system, there are no published cases of this complication when other risk factors are lacking. We report on a 22 year old female patient, with intranasal consumption of 3 grams of cocaine per week for a year, who consulted for intermittent claudication at 200 meters, associated to left lower limb pain and paresthesiae for the last two months. Arterial Doppler ultrasonography showed a stenosis greater than 70% in the superficial left femoral artery. Other probable etiologies were excluded. Treatment was initiated with acetylsalicylic acid, cilostazol and graded physical exercise, associated to support therapy in order to maintain cocaine consumption avoidance, with good response. This case emphasizes the relevance of patients information, as most people ignore the cardiovascular complication of this addiction. It is also essential to inquire about cocaine consumption in young patients with peripheral arteriopathy and no apparent risk factors. PMID:22257455

Pankl, Sonia; Pellegrini, Débora; Bruetman, Julio E

2012-01-01

160

Virus-like particle-induced protection against MRSA pneumonia is dependent on IL-13 and enhancement of phagocyte function.  

PubMed

The importance of the priming of the lung environment by past infections is being increasingly recognized. Exposure to any given antigen can either improve or worsen the outcome of subsequent lung infections, depending on the immunological history of the host. Thus, an ability to impart transient alterations in the lung environment in anticipation of future insult could provide an important novel therapy for emerging infectious diseases. In this study, we show that nasal administration of virus-like particles (VLPs) before, or immediately after, lethal challenge with methicillin-resistant Staphylococcus aureus (MRSA) of mice i) ensures complete recovery from lung infection and near absolute clearance of bacteria within 12 hours of challenge, ii) reduces host response-induced lung tissue damage, iii) promotes recruitment and efficient bacterial clearance by neutrophils and CD11c(+) cells, and iv) protects macrophages from MRSA-induced necrosis. VLP-mediated protection against MRSA relied on innate immunity. Complete recovery occurred in VLP-dosed mice with severe combined immunodeficiency, but not in wild-type mice depleted of either Ly6G(+) or CD11c(+) cells. Early IL-13 production associated with VLP-induced CD11c(+) cells was essential for VLP-induced protection. These results indicate that VLP-induced alteration of the lung environment protects the host from lethal MRSA pneumonia by enhancing phagocyte recruitment and killing and by reducing inflammation-induced tissue damage via IL-13-dependent mechanisms. PMID:22642909

Rynda-Apple, Agnieszka; Dobrinen, Erin; McAlpine, Mark; Read, Amanda; Harmsen, Ann; Richert, Laura E; Calverley, Matthew; Pallister, Kyler; Voyich, Jovanka; Wiley, James A; Johnson, Ben; Young, Mark; Douglas, Trevor; Harmsen, Allen G

2012-05-26

161

Laser-induced incandescence of soot particles in the flue gas evolved by coal pyrolysis  

NASA Astrophysics Data System (ADS)

For the measurement of solid fine particles in pyrolysis systems, laser-induced incandescence (LII) has been proved to be a powerful technique for obtaining volume fraction and primary particles sizes of soot particles. In this paper, a Monte Carlo simulation is developed to analyze the influence on the detected LII flux of soot particles with the presence of coal pyrolysis products between a detector and a laser-induced incandescence control zone. The analysis corresponds to a first approach of the measurement technique, when two distinct aerosols are present around the LII control volume. The evolved flue gas of coal pyrolysis is assumed to be composed of N2, CO2, CO, CH4 and fine carbon particles (soot and fly-ash particles), exhibiting spectrally dependent absorption, and anisotropically light scattering. The developed Monte Carlo simulation is applied to analyze successive absorption and scattering, especially multiple scattering events in any sequence during the propagation of LII emission. The results show that the influence of the flue gas on the detected fluxes is not uniform along the whole wavelengths spectrum. The measurement bias of LII technique for soot particles is presented when modifying coal pyrolysis products composition.

Chen, Linghong; Garo, Annie; Cen, Kefa; Grehan, Gerard

2007-06-01

162

Continuous Production of Prions after Infectious Particles Are Eliminated: Implications for Alzheimer's Disease  

PubMed Central

Rat septal cells, induced to enter a terminal differentiation-like state by temperature shift, produce prion protein (PrP) levels 7x higher than their proliferative counterparts. Host PrP accumulates on the plasma membrane, newly elaborated nanotubes, and cell-to-cell junctions, important conduits for viral spread. To find if elevated PrP increased susceptibility to FU-CJD infection, we determined agent titers under both proliferating and arresting conditions. A short 5 day arrest and a prolonged 140 day arrest increased infectivity by 5x and 122x (>2 logs) respectively as compared to proliferating cells. Total PrP rapidly increased 7x and was even more elevated in proliferating cells that escaped chronic arrest conditions. Amyloid generating PrP (PrP-res), the “infectious prion” form, present at ?100,000 copies per infectious particle, also increased proportionately by 140 days. However, when these highly infectious cells were switched back to proliferative conditions for 60 days, abundant PrP-res continued to be generated even though 4 logs of titer was lost. An identical 4 log loss was found with maximal PrP and PrP-res production in parallel cells under arresting conditions. While host PrP is essential for TSE agent spread and replication, excessive production of all forms of PrP can be inappropriately perpetuated by living cells, even after the initiating infectious agent is eliminated. Host PrP changes can start as a protective innate immune response that ultimately escapes control. A subset of other neurodegenerative and amyloid diseases, including non-transmissible AD, may be initiated by environmental infectious agents that are no longer present.

Miyazawa, Kohtaro; Kipkorir, Terry; Tittman, Sarah; Manuelidis, Laura

2012-01-01

163

Detection of DNA hybridization with LSPR induced by surface relief nanostructure and particle plasmon  

NASA Astrophysics Data System (ADS)

DNA hybridization can be measured with enhanced sensitivity based on localized surface plasmon (LSP) induced by surface nanowire structure. Changes made to the structure result in higher plasmon momentum, which can be coupled to a particle plasmon induced by gold nanoparticles to which DNA molecules are adsorbed. With the insight gained from near-field pattern via calculation, target localization effect is also experimentally shown. We expect that orders of magnitude can be improved in terms of sensitivity if one is to combine the effect of particle-to-LSP coupling and target localization scheme.

Moon, Seyoung; Oh, Youngjin; Ma, Kyungjae; Kim, Donghyun; Lee, Hosub; Lee, Kangtaek

2010-08-01

164

Modeling of alpha-particle-induced soft error rate in DRAM  

SciTech Connect

Alpha-particle-induced soft error in 256M DRAM was numerically investigated. A unified model for alpha-particle-induced charge collection and a soft-error-rate simulator (SERS) was developed. The author investigated the soft error rate of 256M DRAM and identified the bit-bar mode as one of dominant modes for soft error. In addition, for the first time, it was found that trench-oxide depth has a significant influence on soft error rate, and it should be determined by the tradeoff between soft error rate and cell-to-cell isolation characteristics.

Shin, H. [Ewha Womans Univ., Seoul (Korea, Republic of). Dept. of Electronic Engineering

1999-09-01

165

Golli-induced paralysis: a study in anergy and disease.  

PubMed

The Golli-MBP transcription unit contains three Golli-specific exons as well as the seven exons of the classical myelin basic protein (MBP) gene and encodes alternatively spliced proteins that share amino acid sequence with MBP. Unlike MBP, which is a late Ag expressed only in the nervous system, Golli exon-containing gene products are expressed both pre- and postnatally at many sites, including lymphoid tissue, as well as in the central nervous system. To investigate whether Golli-MBP peptides unique to Golli would result in neurological disease, we immunized rats and observed a novel neurological disease characterized by mild paralysis and the presence of groups of lymphocytes in the subarachnoid space but not in the parenchyma of the brain. Disease was induced by Th1-type T cells that displayed an unusual activation phenotype. Primary stimulation in vitro induced T cell proliferation with increased surface CD45RC that did not become down-regulated as it did in other Ag-stimulated cultures. Secondary stimulation of this CD45RChigh population with Ag, however, did not induce proliferation or IL-2 production, although an IFN-gamma-producing population resulted. Proliferation could be induced by secondary stimulation with IL-2 or PMA-ionomycin, suggesting an anergic T cell population. Cells could adoptively transfer disease after secondary stimulation with IL-2, but not with Ag alone. These responses are suggestive of a chronically stimulated, anergic population that can be transiently activated to cause disease, fall back into an anergic state, and reactivated to cause disease again. Such a scenario may be important in chronic human disease. PMID:10201962

Clark, L; Otvos, L; Stein, P L; Zhang, X M; Skorupa, A F; Lesh, G E; McMorris, F A; Heber-Katz, E

1999-04-01

166

Acceleration of Solar Energetic Particle by CME induced shocks  

NASA Astrophysics Data System (ADS)

Solar Energetic Particles (SEPs) may play a major role on the Space Weather forecast since it only takes about 8 minutes (for an representative ion accelerated to 0.5c at a shock's COBPoint at roughly 0.5 AU) to propagate from the Sun to the Earth. COBPoint means Connection of interplanetary magnetic field (IMF) with Observer Point. It is well known that SEPs can be generated by interplanetary (IP) shocks which are driven by the coronal mass ejections (CMEs). Using both a 1.5D magnetohydrodynamic simulation and ACE's EPAM data analysis, "how SEPs are being accelerated by IP shocks?" will be presented. Three SEP events occurred during Halloween 2003 epoch will be presented in this study. We assume that the flares occur close enough to the the ecliptic plane to justify the use of the 1.5D approximation and, thus, the IMF connection from the shocks' COBPoint to ACE. We also assume, as a further "first-look" approximation, that the COBPoint is always on the Sun-Earth line. The correlation coefficient for "IP shock Mach number" vs. "SEPs enhancement" will be calculated to interpret "how SEPs are generated by IP shocks?" thus supporting the empirical and existing discussion concerning the need for a high shock compression ratio.

Wu, Chin-Chun; Liou, Kan; Dryer, Murray; Wu, Shitsan; Tylka, Allan J.

167

Trapped-Particle-Mediated Asymmetry Induced Transport and Damping  

NASA Astrophysics Data System (ADS)

Recent experiments have characterized 6 transport and damping effects caused by trapping separatrices. Here, pure electron plasma columns have a trapping separatrix created by an applied ``squeeze'' voltage. The experiments have now established that this separatrix 1) damps the novel ``Trapped Particle Diocotron Mode''; 2) damps m?>0, kz> 0 Langmuir (plasma) modes; and 3) adds a new dissipative term in resonant 3-wave couplings. When external confinement asymmetries such as magnetic tilt are added, the separatrix 4) damps m?> 0, kz=0 diocotron modes; 5) damps m?= 0, kz> 0 Langmuir modes; and 6) causes bulk plasma expansion and loss. Initial theory analyzed ``collisional'' separatrix transport scaling as ??ee ; but recent theory and experiments characterize ``chaotic'' separatrix transport when the separatrix is not ?-symmetric. The experimental scalings for all 6 effects are unambiguous; and the different B-scalings for collisional and chaotic separatrix transport may explain the commonly observed bulk expansion rate ?PB-1.4. A.A. Kabantsev et al., Phys. Rev. Lett. (Aug. 2008).

Driscoll, C. F.; Kabantsev, A. A.; O'Neil, T. M.; Dubin, D. H. E.; Tsidulko, Yu. A.

2008-11-01

168

Induced disease resistance and gene expression in cereals  

Microsoft Academic Search

Summary Disease resistance strategies reduce chemical input into the environment and are therefore powerful approaches to sustainable agriculture. Induced resis- tance (IR) has emerged as a potential alternative, or a complementary strategy, for crop protection. IR sig- nifies the control of pathogens and pests by prior activation of plant defence pathways. A molecular understanding of IR in cereals, including the

Karl-Heinz Kogel; Gregor Langen

2005-01-01

169

Local effect of IL-4 delivery on polyethylene particle induced osteolysis in the murine calvarium.  

PubMed

Wear particles generated with use of total joint replacements incite a chronic macrophage-mediated inflammatory reaction, which leads to implant failure. Macrophage activation may be polarized into two states, with an M1 proinflammatory state dominating an alternatively activated M2 anti-inflammatory state. We hypothesized that IL-4, an activator of M2 macrophages, could modulate polyethylene (PE) particle-induced osteolysis in an experimental murine model. Four animal groups included (a) calvarial saline injection with harvest at 14 days (b) single calvarial injection of PE particles subcutaneously (SC) without IL-4 (c) PE particles placed as in (b), then IL-4 given SC for 14 consecutive days and (d) PE particles as in (b) then IL-4 beginning 7 days after particle injection for 7 days. The calvarial bone volume to total tissue volume was measured using microCT and histomorphometry. Calvaria were cultured for 24 h to assess release of RANKL, OPG, TNF-?, and IL-1ra and isolation and identification of M1 and M2 specific proteins. MicroCT and histomorphometric analysis showed that bone loss was significantly decreased following IL-4 administration to PE treated calvaria for both 7 and 14 days. Western blot analysis showed an increased M1/M2 ratio in the PE treated calvaria, which decreased with addition of IL-4. Cytokine analysis showed that the RANKL/OPG ratio and TNF-?/IL-1ra ratio decreased in PE-treated calvaria following IL-4 addition for 14 days. IL-4 delivery mitigated PE particle-induced osteolysis through macrophage polarization. Modulation of macrophage polarization is a potential treatment strategy for wear particle induced periprosthetic osteolysis. PMID:23225668

Rao, Allison J; Nich, Christophe; Dhulipala, Lakshmi S; Gibon, Emmanuel; Valladares, Roberto; Zwingenberger, Stefan; Smith, R Lane; Goodman, Stuart B

2012-12-05

170

Exercise-induced vasculitis associated with autoimmune disease.  

PubMed

Exercised-induced vasculitis (EIV) is an underreported and frequently misdiagnosed condition that occurs on the lower extremities shortly after exercise. Most reported cases have presented in healthy-appearing individuals, but some cases have been linked to other disease processes. A case report is presented of recurring EIV in a 65-year-old woman with a history of dermatitis herpetiformis; chronic, mildly elevated liver transaminases of unknown cause; microscopic colitis; celiac disease; multiple miscarriages; and heart block who was found to have autoimmune hepatitis upon workup of her rash. Both EIV and autoimmune hepatitis were misdiagnosed over many years by several clinicians in various specialties. Her family history was remarkable for 2 sisters with systemic lupus erythematosus and similar recurring exercise-induced rashes of the lower extremities, suggesting a familial link for this condition. Clinicians should recognize EIV and consider the possibility that this disorder may be the presenting sign of subclinical connective-tissue diseases. PMID:19681343

Knoell, Keith Allen

2009-06-01

171

A small nonhuman primate model for filovirus-induced disease  

PubMed Central

Ebolavirus and Marburgvirus are members of the filovirus family and induce a fatal hemorrhagic disease in humans and nonhuman primates with 90% case fatality. To develop a small nonhuman primate model for filovirus disease, common marmosets (Callithrix jacchus) were intramuscularly inoculated with wild type Marburgvirus Musoke or Ebolavirus Zaire. The infection resulted in a systemic fatal disease with clinical and morphological features closely resembling human infection. Animals experienced weight loss, fever, high virus titers in tissue, thrombocytopenia, neutrophilia, high liver transaminases and phosphatases and disseminated intravascular coagulation. Evidence of a severe disseminated viral infection characterized principally by multifocal to coalescing hepatic necrosis was seen in EBOV animals. MARV-infected animals displayed only moderate fibrin deposition in the spleen. Lymphoid necrosis and lymphocytic depletion observed in spleen. These findings provide support for the use of the common marmoset as a small nonhuman primate model for filovirus induced hemorrhagic fever.

Carrion, Ricardo; Ro, Youngtae; Hoosien, Kareema; Ticer, Anysha; Brasky, Kathy; de la Garza, Melissa; Mansfield, Keith; Patterson, Jean L.

2011-01-01

172

ULTRAFINE CARBON PARTICLES INDUCE INTERLEUKIN-8 GENE TRANSCRIPTION AND P38 MAPK ACTIVATION IN NORMAL BRONCHIAL EPITHELIAL CELLS  

EPA Science Inventory

Epidemiological studies suggest that ultrafine particles contribute to particulate matter-induced adverse health effects. Interleukin (IL)-8 is an important proinflammatory cytokine in the human lung that is induced in respiratory cells exposed to a variety of environmental insul...

173

Thermal-induced inversion of the magnetic moment in superparamagnetic particles  

Microsoft Academic Search

The method of description of the stochastic dynamics of a classical magnetic moment using both the direct and the reverse Fokker–Planck equations is developed. The average time of thermal-induced inversion of the magnetic moment in superparamagnetic particles with uniaxial and biaxial magnetic anisotropy is calculated.

S. I. Denisov; A. N Yunda

1998-01-01

174

Thermal-induced inversion of the magnetic moment in superparamagnetic particles  

NASA Astrophysics Data System (ADS)

The method of description of the stochastic dynamics of a classical magnetic moment using both the direct and the reverse Fokker-Planck equations is developed. The average time of thermal-induced inversion of the magnetic moment in superparamagnetic particles with uniaxial and biaxial magnetic anisotropy is calculated.

Denisov, S. I.; Yunda, A. N.

1998-03-01

175

Alpha-particle induced charge transfer between closely spaced trench capacitor memory cells  

Microsoft Academic Search

A detailed analysis of various mechanisms involved in alpha-particle induced charge transfer between two trench type dRAM cells is reported and an analytical model has been developed to represent the transfered charge. The results compare very favorably with detailed simulation results.

J. H. Chern; P. Yang; P. Pattnaik; J. A. Seitchik; K. C.-K. Weng

1985-01-01

176

URBAN PARTICLE-INDUCED PULMONARY ARTERY CONSTRUCTION IS MEDIATED BY SUPEROXIDE PRODUCTION  

EPA Science Inventory

URBAN PARTICLE-INDUCED PULMONARY ARTERY CONSTRICTION IS MEDIATED BY SUPEROXIDE PRODUCTION.Jacqueline D. Carter, Zhuowei Li, Lisa A. Dailey, Yuh-Chin T. Huang. CEMALB, University of North Carolina, and ORD, US EPA, Chapel Hill, North Carolina. Exposure to particulate matter...

177

The role of adsorbed endotoxin in particle-induced stimulation of cytokine release  

Microsoft Academic Search

Numerous in vitro models have demonstrated the capacity of wear particles to stimulate the release of soluble pro-inflammatory products with the ability to induce local bone resorption. Recent observations have demonstrated that binding of lipopolysaccharide (LPS) to particulate wear debris can significantly modulate the pattern of cell response in the in vitro models. These findings raise concerns over the possible

David R. Cho; Arun S. Shanbhag; Chi-Yuan Hong; George R. Baran; Steven R. Goldring

2002-01-01

178

CARDIOVASCULAR FUNCTIONAL, CELLULAR, AND MOLECULAR EFFECTS INDUCED BY EMISSION SOURCE PARTICLE CONSTITUENTS  

EPA Science Inventory

Epidemiological, clinical and toxicological studies have demonstrated the ability of ambient PM and certain emission source particles to altered autonomic control of the heart and induce arrhythmia. A number of hypotheses have been proposed to explain these effects such as direct...

179

Influence of resistivity on energetic trapped particle-induced internal kink modes  

SciTech Connect

The influence of resistivity on energetic trapped particle-induced internal kink modes, dubbed ''fishbones'' in the literature, explored. A general dispersion relation, which recovers the ideal theory in its appropriate limit, is derived and analyzed. Implications of the theory for present generation fusion devices such as the Joint European Torus are discussed. 8 refs., 2 figs.

Biglari, H.; Chen, L.

1986-01-01

180

Historical trend in alpha-particle induced soft error rates of the AlphaTM microprocessor  

Microsoft Academic Search

In this work, we present ?-particle induced soft error rates (SER) for several generations of the Alpha microprocessor. In our analysis, we focus in particular on the historical trend of soft error rates for memory cells and random core logic. Our data demonstrate the impact of process, design and packaging material on the SER. The total chip-level SER trend has

N. Seifert; D. Moyer; N. Leland; R. Hokinson

2001-01-01

181

Study of basic mechanisms induced by an ionizing particle on simple structures  

Microsoft Academic Search

The currents induced by an ionizing particle in a diode and a bar are compared. A short track, located within the structure, and a long track passing through it are considered. Analysis of the mechanisms involved is proposed to explain why the observed effects are approximately the same

G. Hubert; J.-M. Palau; Ph. Roche; B. Sagnes; J. Gasiot; M. C. Calvet

1999-01-01

182

Study of basic mechanisms induced by an ionizing particle on simple structures  

Microsoft Academic Search

The currents induced by an ionizing particle in a diode and a bar are compared. A short track, located within the structure, and a long track passing through it are considered. Analysis of the mechanisms involved is proposed to explain why the observed effects are approximately the same

G. Hubert; J.-M. Palau; Ph. Roche; B. Sagnes; J. Gasiot; M. C. Calvet

2000-01-01

183

Geometry and energy loss features of charged particle production in fast-neutron induced reactions  

Microsoft Academic Search

Raw data reduction of charged particle production in fast neutron induced reactions must take into account specific characteristics of this type of experiment. A calculation procedure is presented which considers particular features such as: the thickness of targets, beam dimensions on the target, the beam profile, relative target-telescope angular position etc. It results in a simulation programme (Perten) of the

I. Slypen; V. Corcalciuc; J. P. Meulders

1994-01-01

184

DIESEL EXHAUST PARTICLE INDUCED GENE EXPRESSION CHANGES IN A MURINE MUCOSAL SENSITIZATION MODEL  

EPA Science Inventory

Studies in humans and animals have shown diesel exhaust particles (DEP) can act as an immunological adjuvant to enhance the development of allergic lung disease and this effect is influenced by the chemical composition of the DEP. The adjuvancy of NIST SRM 2975 (NDEP) generated...

185

Genetic influence on cigarette-induced cardiovascular disease.  

PubMed

Cigarette smoking as an addictive habit has accompanied human beings for more than 4 centuries. It is also one of the most potent and prevalent environmental health risks human beings are exposed to, and it is responsible for more than 1000 deaths each day in the United States. With recent research progress, it becomes clear that cigarette smoking can cause almost all major diseases prevalent today, such as cancer or heart disease. These detrimental effects are not only present in active smokers who choose the risk, but also to innocent bystanders, as passive smokers, who are exposed to cigarettes not-by-choice. While the cigarette-induced harm to human health is indiscriminate and severe, the degree of damage also varies from individual to individual. This intersubject variability in cigarette-induced pathologies is partly mediated by genetic variants of genes that may participate in detoxification process, eg, cytochrome P450 (CYP), cellular susceptibility to toxins, such as p53, or disease development. Through population studies, we have learned that certain CYP1A1 variants, such as Mspl polymorphism, may render the carriers more susceptible to cigarette-induced lung cancer or severe coronary atherosclerosis. The endothelial nitric oxide synthase intron 4 rare allele homozygotes are more likely to have myocardial infarction if they also smoke. In vitro experimental approach has further demonstrated that cigarettes may specifically regulate these genes in genotype-dependent fashion. While we still know little about genetic basis and molecular pathways for cigarette-induced pathological changes, understanding these mechanisms will be of great value in designing strategies to further reduce smoking in targeted populations, and to implement more effective measures in prevention and treatment of cigarette-induced diseases. PMID:12704594

Wang, Xing Li; Raveendran, Muthuswamy; Wang, Jian

186

Concentrated ambient air particles induce vasoconstriction of small pulmonary arteries in rats.  

PubMed Central

The objective of this study was to determine whether short-term exposures to concentrated ambient particles (CAPs) alter the morphology of small pulmonary arteries in normal rats and rats with chronic bronchitis (CB). Sprague-Dawley male rats were exposed to CAPs, using the Harvard Ambient Particle Concentrator, or to particle-free air (sham) under identical conditions during 3 consecutive days (5 hr/day) in six experimental sets. CB was induced by exposure to 276 +/- 9 ppm of sulfur dioxide (5 hr/day, 5 days/week, 6 weeks). Physicochemical characterization of CAPs included measurements of particle mass, size distribution, and composition. Rats were sacrificed 24 hr after the last CAPs exposure. Histologic slides were prepared from random sections of lung lobes and coded for blinded analysis. The lumen/wall area (L/W) ratio was determined morphometrically on transverse sections of small pulmonary arteries. When all animal data (normal and CB) were analyzed together, the L/W ratios decreased as concentrations of fine particle mass, silicon, lead, sulfate, elemental carbon, and organic carbon increased. In separate univariate analyses of animal data, the association for sulfate was significant only in normal rats, whereas silicon was significantly associated in both CB and normal rats. In multivariate analyses including all particle factors, the association with silicon remained significant. Our results indicate that short-term CAPs exposures (median, 182.75 micro g/m3; range, 73.50-733.00 micro g/m3) can induce vasoconstriction of small pulmonary arteries in normal and CB rats. This effect was correlated with specific particle components and suggests that the pulmonary vasculature might be an important target for ambient air particle toxicity.

Batalha, Joao R F; Saldiva, Paulo H N; Clarke, Robert W; Coull, Brent A; Stearns, Rebecca C; Lawrence, Joy; Murthy, G G Krishna; Koutrakis, Petros; Godleski, John J

2002-01-01

187

Hydrodynamic interactions in metal rod-like particle suspensions due to induced charge electroosmosis  

SciTech Connect

We present a theoretical and experimental study of the role of hydrodynamic interactions on the motion and dispersion of metal rod-like particles in the presence of an externally applied electric field. In these systems, the electric field polarizes the particles and induces an electroosmosis flow relative to the surface of each particle. The simulations include the effect of the gravitational body force, buoyancy, far-field hydrodynamic interactions, near-field lubrication forces, and electric field interactions. The particles in the simulations and experiments were observed to experience repeated pairing interactions in which they come together axially with their ends approaching each other, slide past one another until their centers approach, and then push apart. These interactions were confirmed in measurements of particle orientations and velocities, pair distribution functions, and net dispersion of the suspension. For large electric fields, the pair distribution functions show accumulation and depletion regions consistent with many pairing events. For particle concentrations of 1e8 particles/mL and higher, dispersion within the suspension dramatically increases with increased field strength.

Rose, K A; Hoffman, B; Saintillan, D; Shaqfeh, E G; Santiago, J G

2008-05-05

188

Hamiltonian stochastic processes induced by successive wave-particle interactions in stimulated Raman scattering.  

PubMed

The long-time dynamics of particles interacting resonantly with large-amplitude coherent plasma wave is investigated in the kinetic regime of stimulated Raman scattering in which particle trapping plays a major role (and which corresponds to a high value of the parameter k_{EPW}lambda_{D}, where k_{EPW} is the plasma wave vector and lambda_{D} is the electron Debye length). Using Vlasov simulations, the dynamics of such particles become stochastic when repeated wave-particle interactions take place. For small values of the ratio tau_{auto}/tau_{b} of the autocorrelation time to the bounce time of particle (condition usually met in backward propagation of the scattered wave) the turbulent regime results in the merging of phase-space trapping vortices according to a weak turbulencelike scenario. For high values of tau_{auto}/tau_{b} (or narrow spectrum of longitudinal electric field as met when only one plasma wave is present), the stochasticity is now induced by particle trapping, detrapping, and retrapping in the adiabatically fluctuating field. The stochastic transitions performed by resonant particles above (or below) the separatrix limit in phase space determine now the long-time plasma evolution. PMID:19518356

Ghizzo, A; Del Sarto, D; Reveille, T

2009-04-14

189

Particle irradiation induces FGF2 expression in normal human lens cells.  

PubMed

Particle Irradiation Induces FGF2 Expression in Normal Human Lens Cells. Particle radiations, including both proton and helium-ion beams, have been used to successfully treat choroidal melanoma, but with the complication of radiation-induced cataract. We have investigated a role for radiation-induced changes in the expression of basic fibroblast growth factor (FGF2) gene expression as part of the mechanism(s) underlying lens cell injury associated with cataract. Normal human lens epithelial (HLE) cells were cultured in vitro on extracellular matrix (ECM) originated from bovine corneal endothelial cells. This study reports evidence for rapid but transient induction of FGF2 transcripts, an increase of between 5- and 8-fold, within 0.5 h after exposure to particle radiation, followed by another wave of increased transcription at 2-3 h postirradiation. Immunofluorescence results confirm the enhanced levels of FGF2 protein rapidly after exposure to protons or helium ions, followed by another wave of increased activity unique to helium at 6 h postirradiation. This second wave of increased immunoreactivity was not observed in the proton-irradiated samples. Total FGF2 protein analysis after helium-ion exposures shows induced expression of three FGF2 isoforms, with an increase of up to 2-fold in the 18-kDa low-molecular-weight species. Studies of the effects of protons on individual FGF2 protein isoforms are in progress. Several mechanisms involving a role for FGF2 in radiation-induced cataract are discussed. PMID:11025644

Chang, P Y; Bjornstad K, A; Chang, E; McNamara, M; Barcellos-Hoff, M H; Lin, S P; Aragon, G; Polansky, J R; Lui, G M; Blakely, E A

2000-11-01

190

Lactobacillus GG in inducing and maintaining remission of Crohn's disease  

PubMed Central

Background Experimental studies have shown that luminal antigens are involved in chronic intestinal inflammatory disorders such as Crohn's disease and ulcerative colitis. Alteration of the intestinal microflora by antibiotic or probiotic therapy may induce and maintain remission. The aim of this randomized, placebo-controlled trial was to determine the effect of oral Lactobacillus GG (L. GG) to induce or maintain medically induced remission. Methods Eleven patients with moderate to active Crohn's disease were enrolled in this trial to receive either L. GG (2 × 109 CFU/day) or placebo for six months. All patients were started on a tapering steroid regime and received antibiotics for the week before the probiotic/placebo medication was initiated. The primary end point was sustained remission, defined as freedom from relapse at the 6 months follow-up visit. Relapse was defined as an increase in CDAI of >100 points. Results 5/11 patients finished the study, with 2 patients in each group in sustained remission. The median time to relapse was 16 ± 4 weeks in the L. GG group and 12 ± 4.3 weeks in the placebo group (p = 0.5). Conclusion In this study we could not demonstrate a benefit of L. GG in inducing or maintaining medically induced remission in CD.

Schultz, Michael; Timmer, Antje; Herfarth, Hans H; Sartor, R Balfour; Vanderhoof, Jon A; Rath, Heiko C

2004-01-01

191

Nanoembossing induced ferroelectric lithography on PZT films for silver particle patterning.  

PubMed

The concept of growing nanosize particles on polarized ferroelectric domain areas is known as ferroelectric lithography (FL). Here, a further step of technical development was achieved by combining nanoembossing technique with the FL to realize the selective growth of silver on the polarized areas induced by nanoembossing. The induced rearrangements of domain distributions by embossing in the ferroelectric films have been characterized by piezoresponse force microscopy (PFM). The selective photochemical reduction of silver particles on the embossed nanostructures associated with the underlying domain patterns created by the nanoembossing process has been successfully demonstrated. This nanoembossing induced ferroelectric lithography (NIFL) developed in this work is expected to create an alternative route for nanoscale patterning of metals. PMID:21838248

Shen, Zhenkui; Qu, Xinping; Chen, Yifang; Liu, Ran

2011-08-12

192

Indirect control of transport and interaction-induced negative mobility in an overdamped system of two coupled particles  

NASA Astrophysics Data System (ADS)

One-dimensional transport of an overdamped Brownian particle biased by an external constant force does not exhibit negative mobility. However, when the particle is coupled to another particle, negative mobility can arise. We present a minimal model and propose a scenario in which only one (say, the first) particle is dc biased by a constant force and ac driven by an unbiased harmonic signal. In this way we intend to achieve two aims at once: (i) negative mobility of the first particle, which is exclusively induced by coupling to the second particle and (ii) indirect control of the transport properties of the second particle by manipulating the first particle only. For instance, the sign and amplitude of the averaged stationary velocity of the second particle can be steered by the driving applied to the first particle. As an experimentally realizable system, we propose two coupled resistively shunted Josephson junctions.

Januszewski, M.; ?uczka, J.

2011-05-01

193

Quantitative elemental detection of size-segregated particles using laser-induced breakdown spectroscopy  

NASA Astrophysics Data System (ADS)

In order to simulate coal combustion and develop optimal and stable boiler control systems in real power plants, it is imperative to obtain the detailed information in coal combustion processes as well as to measure species contents in fly ash, which should be controlled and analyzed for enhancing boiler efficiency and reducing environmental pollution. The fly ash consists of oxides (SiO2, Al2O3, Fe2O3, CaO, and so on), unburned carbon, and other minor elements. Recently laser-induced breakdown spectroscopy (LIBS) technique has been applied to coal combustion and other industrial fields because of the fast response, high sensitivity, real-time and non-contact features. In these applications it is important to measure controlling factors without any sample preparation to maintain the real-time measurement feature. The relation between particle content and particle diameter is also one of the vital researches, because compositions of particles are dependent on their diameter. In this study, we have detected the contents of size-segregated particles using LIBS. Particles were classified by an Anderson cascade impactor and their contents were measured using the output of 1064 nm YAG laser, a spectrograph and an ICCD camera. The plasma conditions such as plasma temperature are dependent on the size of particles and these effects must be corrected to obtain quantitative information. The plasma temperature was corrected by the emission intensity ratio from the same atom. Using this correction method, the contents of particles can be measured quantitatively in fixed experimental parameters. This method was applied to coal and fly ash from a coal-fired burner to measure unburned carbon and other contents according to the particle diameter. The acquired results demonstrate that the LIBS technique is applicable to measure size-segregated particle contents in real time and this method is useful for the analysis of coal combustion and its control because of its sensitive and fast analysis features.

Wang, Zhen Zhen; Deguchi, Yoshihiro; Kuwahara, Masakazu; Taira, Takuya; Zhang, Xiao Bo; Yan, Jun Jie; Liu, Ji Ping; Watanabe, Hiroaki; Kurose, Ryoichi

2013-09-01

194

Lateral aggregation induced by magnetic perturbations in a magnetorheological fluid based on non-Brownian particles  

NASA Astrophysics Data System (ADS)

A study of lateral aggregation, induced by an oscillatory field, in a magnetorheological fluid based on non-Brownian magnetic particles is presented. We investigate the behavior of chains formed by the particles, due to the simultaneous application of a static magnetic field and a sinusoidal magnetic field transverse to each other. We show that the effective oscillating field enhances the aggregation process. We discuss this result in terms of an effective particle concentration induced by the oscillating field when chains oscillate angularly and sweep the area around them. The oscillating field produces a lateral aggregation similar to that observed in systems composed of Brownian particles which is induced by thermal fluctuations. We study the effect of the oscillating field on the angular amplitude described by single chains. It is observed that the angular amplitude decreases as the frequency of the oscillating field increases; we discuss this behavior numerically in terms of a simple model for this system. Lateral aggregation is studied in detail in isolated pairs of chains of equal length at several conditions of separation and displacement. From the results, a phase diagram is obtained showing the conditions under which aggregation is possible.

Moctezuma, R. E.; Donado, F.; Arauz-Lara, J. L.

2013-09-01

195

Disease-specific induced pluripotent stem cells: a platform for human disease modeling and drug discovery  

PubMed Central

The generation of disease-specific induced pluripotent stem cell (iPSC) lines from patients with incurable diseases is a promising approach for studying disease mechanisms and drug screening. Such innovation enables to obtain autologous cell sources in regenerative medicine. Herein, we report the generation and characterization of iPSCs from fibroblasts of patients with sporadic or familial diseases, including Parkinson's disease (PD), Alzheimer's disease (AD), juvenile-onset, type I diabetes mellitus (JDM), and Duchenne type muscular dystrophy (DMD), as well as from normal human fibroblasts (WT). As an example to modeling disease using disease-specific iPSCs, we also discuss the previously established childhood cerebral adrenoleukodystrophy (CCALD)- and adrenomyeloneuropathy (AMN)-iPSCs by our group. Through DNA fingerprinting analysis, the origins of generated disease-specific iPSC lines were identified. Each iPSC line exhibited an intense alkaline phosphatase activity, expression of pluripotent markers, and the potential to differentiate into all three embryonic germ layers: the ectoderm, endoderm, and mesoderm. Expression of endogenous pluripotent markers and downregulation of retrovirus-delivered transgenes [OCT4 (POU5F1), SOX2, KLF4, and c-MYC] were observed in the generated iPSCs. Collectively, our results demonstrated that disease-specific iPSC lines characteristically resembled hESC lines. Furthermore, we were able to differentiate PD-iPSCs, one of the disease-specific-iPSC lines we generated, into dopaminergic (DA) neurons, the cell type mostly affected by PD. These PD-specific DA neurons along with other examples of cell models derived from disease-specific iPSCs would provide a powerful platform for examining the pathophysiology of relevant diseases at the cellular and molecular levels and for developing new drugs and therapeutic regimens.

Jang, Jiho; Yoo, Jeong-Eun; Lee, Jeong-Ah; Lee, Dongjin R.; Kim, Ji Young; Huh, Yong Jun; Kim, Dae-Sung; Park, Chul-Yong; Hwang, Dong-Youn; Kim, Han-Soo

2012-01-01

196

N-Acetylcholinesterase-Induced Apoptosis in Alzheimer's Disease  

Microsoft Academic Search

BackgroundAlzheimer's disease (AD) involves loss of cholinergic neurons and Tau protein hyper-phosphorylation. Here, we report that overexpression of an N-terminally extended “synaptic” acetylcholinesterase variant, N-AChE-S is causally involved in both these phenomena.Methodology and Principal FindingsIn transfected primary brain cultures, N-AChE-S induced cell death, morphological impairments and caspase 3 activation. Rapid internalization of fluorescently labeled fasciculin-2 to N-AChE-S transfected cells indicated

Debra Toiber; Amit Berson; David Greenberg; Sophia Diamant; Hermona Soreq; Joseph Najbauer

2008-01-01

197

Interstitial Lung Disease Induced by Drugs and Radiation  

Microsoft Academic Search

An ever-increasing number of drugs can reproduce variegated patterns of naturally occurring interstitial lung disease (ILD), including most forms of interstitial pneumonias, alveolar involvement and, rarely, vasculitis. Drugs in one therapeutic class may collectively produce the same pattern of involvement. A few drugs can produce more than one pattern of ILD. The diagnosis of drug-induced ILD (DI-ILD) essentially rests on

Philippe Camus; Annlyse Fanton; Philippe Bonniaud; Clio Camus; Pascal Foucher

2004-01-01

198

Multivalent virus-like-particle vaccine protects against classic and variant infectious bursal disease viruses.  

PubMed

Nucleotide sequences that encode the pVP2 proteins from a variant infectious bursal disease virus (IBDV) strain designated USA08MD34p and a classic IBDV strain designated Mo195 were produced with the use of reverse-transcriptase-polymerase chain reaction (RT-PCR) and cloned into a pGEM-T Easy vector. A nucleotide sequence that encodes the VP3 protein was also produced from the USA08MD34p viral genome with the use of RT-PCR and cloned into a pGEM-T Easy vector. The VP3 and pVP2 clones were inserted into the pVL1393 baculovirus transfer vector and sequenced to confirm their orientation to the promoter and to ensure they contained uninterrupted open reading frames. Recombinant baculoviruses were constructed by transfection in Sf9 cells. Three recombinant baculoviruses were produced and contained the USA08MD34p-VP3, USA08MD34p-pVP2, or Mo195-pVP2 genomic sequences. Virus-like particles (VLPs) were observed with the use of transmission electron microscopy when the USA08MD34p-VP3 baculovirus was co-inoculated into Sf9 cells with either of the pVP2 constructs. VLPs were also observed when the USA08MD34p-pVP2 and Mo195-pVP2 were coexpressed with USA08MD34p-VP3. These multivalent VLPs contained both classic and variant pVP2 molecules. Stability tests demonstrated the VLPs were stable at 4 and 24 C for 8 wk. The USA08MD34p, Mo195, and multivalent VLPs were used to vaccinate chickens. They induced an IBDV-specific antibody response that was detected by enzyme-linked immunosorbent assay (ELISA), and virus-neutralizing antibodies were detected in vitro. Chickens vaccinated with the multivalent VLPs were protected from a virulent variant IBDV strain (V1) and a virulent classic IBDV strain (STC). The results indicate the multivalent VLPs maintained the antigenic integrity of the variant and classic viruses and have the potential to serve as a multivalent vaccine for use in breeder-flock vaccination programs. PMID:23678728

Jackwood, Daral J

2013-03-01

199

Autoimmune and virus-induced demyelinating diseases. A review.  

PubMed Central

Patterns of demyelination are described in several autoimmune and virus-induced demyelinating diseases of the peripheral and central nervous system. Myelin can be destroyed by injuries that affect either the myelin-supporting cells and/or the myelin lamellae. After destruction of the supporting cells, the related disintegrating sheaths are stripped off axons by invading phagocytes. Virus-induced cytolysis can occur with or without participation of immune responses, as demonstrated in subacute sclerosing panencephalitis and progressive mutlifocal leukoencephalopathy, respectively. Autoimmune demyelination is characterized by disintegration of myelin sheaths in periventular, mononuclear cell infiltrates. Myelin lamellae rather than the myelin-supporting cells are the target of the allergic reaction. The lamellae are lysed in focal areas when in contact with presumably sensitized mononuclear cells. The damaged sheaths are then removed in a nonspecific manner by invading macrophages that strip the myelin remnant off the axons. This sequence of changes is best revealed in experimental and human autoimmune demyelination of peripheral nerves, ie, allergic neuritis and idiopathic polyneutris (the Guillain-Barré syndrome). Autoimmune demyelination triggered by virus infection is described in Marek's disease and postinfectious Theiler's virus myelitis. Changes in canine distemper are discussed with reference to both autoimmune and virus-induced demyelination. The observations are compared with lesions in multiple sclerosis, the most common human demyelinating disease of unknown etiology. Images Figure 7 Figure 8 Figure 9 Figure 10 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 1

Lampert, P. W.

1978-01-01

200

Application of laser-induced incandescence to suspended carbon black particles.  

PubMed

For the first time, to the best of our knowledge, laser-induced incandescence (LII) has successfully been applied to carbon black suspensions. A linear correlation between the experimentally derived signal decay time and the mean primary particle size, determined by transmission electron microscopy, for different carbon black particles was found. Moreover, a nonlinear relation similar to that known from measurements of aerosols was observed for the peak LII signal and the laser fluence. Despite different heat transfer properties, the signal decay time was not influenced by the solvents used. PMID:17603623

Sommer, Roland; Leipertz, Alfred

2007-07-01

201

Golf ball-like particles fabricated by nonsolvent/solvent-induced phase separation method.  

PubMed

Monodisperse poly(styrene-co-acrylic acid) (P(S-co-AA)) particles having a "golf ball-like" shape were prepared by nonsolvent/solvent-induced phase separation process. The method is simple and easy operation. The nonsolvent/solvent phase was mixture of butanol, n-heptane and toluene. The dimpled surface comes from the aggregation of oil droplets on the surface of polymer spheres. The dimple's morphology can be controlled by the polymer templates, dispersion medium, reaction time, and temperature. Reverse Pickering emulsion model was suggested for the formation of golf ball-like particles. PMID:23116859

Dai, Mingdong; Song, Linyong; Nie, Wangyan; Zhou, Yifeng

2012-10-10

202

Flux induced growth of sub-Kelvin nano-particles by organic vapor  

NASA Astrophysics Data System (ADS)

New particle formation (NPF) in the atmosphere strongly influences the concentration of atmospheric aerosol, and therefore its impact on climate. New particle formation is a two-stage process consisting of homogeneous nucleation of thermodynamically stable clusters followed by growth of these clusters to a detectable size (> 3 nm). Due to the large coagulation rate of clusters smaller than 3 nm with the pre-existing aerosol population, for new particle formation to take place, these clusters need to grow sufficiently fast before being removed by coagulation. While some previous modeling and field studies have indicated that condensation of low-volatility organic vapor may play an important role in the initial growth of the clusters, it is suggested that due to the small size of the clusters, the strong Kelvin effect may prevent typical ambient organics from condensing on these clusters. Here we show that the particle number flux induced by the heterogeneous nucleation of organics vapor can effectively grow clusters substantially smaller than the Kelvin diameter, traditionally considered as the minimum size of particles that can be grown through condensation. Including this flux can lead to a factor of 10 or higher increases in the predicted rates of new particle formation and the production of cloud condensation nuclei.

Wang, J.; McGraw, R. L.; Kuang, C.

2011-12-01

203

Moyamoya disease presenting with paroxysmal exercise-induced dyskinesia.  

PubMed

We report a patient with moyamoya disease presenting with paroxysmal exercise-induced dyskinesia (PED). A 31-year-old lathe man developed recurrent attacks of paroxysmal hemichorea. The attacks always affected his left limbs and occurred either after several hours of working or while playing football. The duration of attacks ranged from 30 min to 4h. Attacks were not provoked by sudden movements, consumption of coffee or alcohol, hyperventilation, emotional stress, exposure to cold or passive movement. An MRI of the brain showed no parenchymal lesions. However, (99m)Tc-ethylcysteine dimer SPECT study showed hypoperfusion in the right striatum. Digital subtraction angiography showed stenosis of the right internal carotid and middle cerebral artery with prominent basal collaterals, which was compatible with moyamoya disease. Imaging studies of the cerebral arteries should be done in patients with clinical features of PED in order to detect possible cases of moyamoya disease. PMID:16952479

Lyoo, Chul Hyoung; Kim, Dong Joon; Chang, Hyuk; Lee, Myung Sik

2006-09-06

204

Disease modelling using induced pluripotent stem cells: status and prospects.  

PubMed

The ability to convert human somatic cells into induced pluripotent stem cells (iPSCs) is allowing the production of custom-tailored cells for drug discovery and for the study of disease phenotypes at the cellular and molecular level. IPSCs have been derived from patients suffering from a large variety of disorders with different severities. In many cases, disease related phenotypes have been observed in iPSCs or their lineage-specific progeny. Several proof of concept studies have demonstrated that these phenotypes can be reversed in vitro using approved drugs. However, several challenges must be overcome to take full advantage of this technology. Here, we highlight recent advances in the field and discuss the main challenges associated with this technology as it applies to disease modelling. PMID:23148027

Pomp, Oz; Colman, Alan

2012-11-13

205

The role of adsorbed endotoxin in particle-induced stimulation of cytokine release.  

PubMed

Numerous in vitro models have demonstrated the capacity of wear particles to stimulate the release of soluble pro-inflammatory products with the ability to induce local bone resorption. Recent observations have demonstrated that binding of lipopolysaccharide (LPS) to particulate wear debris can significantly modulate the pattern of cell response in the in vitro models. These findings raise concerns over the possible role of LPS in the pathogenesis of aseptic loosening after total joint replacements, and also indicates the importance of controlling for possible confounding effects of LPS contamination in the in vitro models used to study the reactive nature of wear debris. Our studies were undertaken to rigorously analyze the effects of particle-associated LPS on cell responses and to assess the efficacy of different treatment protocols to inactivate LPS associated with different particulate materials. Particles of cobalt-chrome alloy, titanium-6-aluminum-4-vanadium, titanium nitride and silica were pretreated with LPS and exposed to multiple treatment protocols. When cells were treated with "as-received" particles prepared by washing in ethanol, small amounts of TNF-alpha, IL-1beta. and IL-1alpha were detected. In contrast, all particle species pretreated with LPS produced marked increases in TNF-alpha, IL-1alpha, and IL-1beta release, as well as upregulation of corresponding mRNA levels even after ethanol washing. Boiling the LPS-pretreated particles in 1% acetic acid or autoclaving and baking the particles also markedly reduced and in some instances abolished the effect of the LPS-pretreatment. This indicates that LPS binds to the surface of particles of diverse composition and that the bound LPS is biologically active. Treatment protocols to inactivate particle-associated LPS demonstrated significant differences in efficacy. When the most rigorous treatments were utilized, essentially all LPS activity could be eliminated. Particles treated with these methods retained some capacity to stimulate cytokine release, but activities were markedly reduced. These results provide further evidence indicating that LPS contamination of particulate materials can markedly enhance their biological activity. This potential confounding effect needs to be carefully monitored and controlled in the in vitro model systems used to evaluate wear particles. Furthermore, the presence of particle-associated endotoxin at the bone-implant interface in vivo could markedly enhance the adverse biological activity of particulate wear debris. PMID:12168658

Cho, David R; Shanbhag, Arun S; Hong, Chi-Yuan; Baran, George R; Goldring, Steven R

2002-07-01

206

Shear-induced particle migration and margination in a cellular suspension  

NASA Astrophysics Data System (ADS)

We simulate the cross-flow migration of rigid particles such as platelets in a red blood cell (RBC) suspension using the Stokes flow boundary integral equation method. Two types of flow environments are investigated: a suspension undergoing a bulk shear motion and a suspension flowing in a microchannel or duct. In a cellular suspension undergoing bulk shear deformation, the cross-flow migration of particles is diffusional. The velocity fluctuations in the suspension, which are the root cause of particle migration, are analyzed in detail, including their magnitude, the autocorrelation of Lagrangian tracer points and particles, and the associated integral time scales. The orientation and morphology of red blood cells vary with the shear rate, and these in turn cause the dimensionless particle diffusivity to vary non-monotonically with the flow capillary number. By simulating RBCs and platelets flowing in a microchannel of 34 ?m height, we demonstrate that the velocity fluctuations in the core cellular flow region cause the platelets to migrate diffusively in the wall normal direction. A mean lateral velocity of particles, which is most significant near the edge of the cell-free layer, further expels them toward the wall, leading to their excess concentration in the cell-free layer. The calculated shear-induced particle diffusivity in the cell-laden region is in qualitative agreement with the experimental measurements of micron-sized beads in a cylindrical tube of a comparable diameter. In a smaller duct of 10 × 15 ?m cross section, the volume exclusion becomes the dominant mechanism for particle margination, which occurs at a much shorter time scale than the migration in the bigger channel.

Zhao, Hong; Shaqfeh, Eric S. G.; Narsimhan, Vivek

2012-01-01

207

Purification, characterization and serological detection of virus-like particles associated with banana bunchy top disease in Australia  

Microsoft Academic Search

Isometric virus-like particles, 18 nm in diameter, have been isolated from banana (Musa spp.) affected by bunchy top disease in Australia. Banana bunchy top disease-associated virus-like particles (BBTV) banded as a single component with buoyant density of 1-28 to 1.29 g\\/ml in Cs2SO4 and sedimented at about 46S in isokinetic sucrose density gradients. The A260\\/.42S 0 of purified preparations was

John E. Thomas; Ralf G. Dietzgen

1991-01-01

208

A time-of-flight telescope for charged particles produced in neutron-induced reactions  

NASA Astrophysics Data System (ADS)

A counter telescope has been developed for the study of neutron-induced charged-particle-producing reactions. This spectrometer differs from those conventionally used for such studies in that it has a flight path long enough (2 m) to allow a fairly accurate energy determination. The use of a pulsed beam with such a spectrometer permits the particle energy to be determined in two ways: from the signal produced by the E counter and from the time-of-flight. This redundancy allows a reduction in background relative to the typical telescope if we demand consistency in the two values for a pulse to be accepted. In addition, the velocity determination through time-of-flight makes a better energy resolution possible than would normally be possible for low-energy charged-particles detected in a scintillator. Present address: Radiological Research Accelerator Facility, Columbia University, Nevis Laboratory, Irvington, NY 10533, USA.

Ahmad, M.; Graham, S. L.; Grimes, S. M.; Longfellow, R.; Satyanarayana, H.; Randers-Pehrson, G.

1985-01-01

209

Gyrokinetic {delta}f particle simulations of toroidicity-induced Alfven eigenmode  

SciTech Connect

Gyrokinetic {delta}f particle simulation is used to investigate toroidicity-induced Alfven eigenmodes (TAEs). Both thermal ions and energetic particles are fully kinetic, but a reduced fluid model is used for the electrons. Simulation of a single n=2 global TAE is carefully analyzed and benchmarked with an eigenmode analysis, and a very good agreement is achieved in both mode structure and mode frequency. The instability of the mode in the presence of energetic particles is demonstrated. In particular, gyrokinetic simulations demonstrate the kinetic damping effect of thermal ions, where the finite radial structure of kinetic Alfven waves is well resolved and the damping rate is compared to and found to agree well with analytical theory.

Lang Jianying; Chen Yang; Parker, Scott E. [University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Fu Guoyong [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2009-10-15

210

Shear-induced particle rotation and its effect on electrorheological and dielectric properties in cellulose suspension.  

PubMed

Electrorheological (ER) and dielectric properties under high electric fields were measured simultaneously on hydroxypropylcellulose suspension. When measuring these properties as a function of frequency of the electric field, we found a positive peak in each spectrum of the ER effect and the first-order dielectric permittivity while a negative one in the spectrum of the third-order dielectric permittivity with these peak frequencies nearly equal to (shear rate)/4pi . Referring to the well-known results for the particle rotation in the sheared suspension, it is suggested that the observed peaks are due to shear-induced particle rotation and the rotation occurs even under high electric field. On the basis of these results, effects of the particle rotation on the ER and the dielectric properties are discussed. PMID:15697367

Misono, Y; Negita, K

2004-12-28

211

Effect of oxide particle distribution on the helium-induced fracture of copper  

SciTech Connect

Long-term exposure to tritium (H{sup 3}) gas can degrade the mechanical properties of copper alloys while similar exposure to protium (H{sup 1}) gas does not cause such degradation. This difference in behavior is attributed to the presence of helium which is generated by the radioactive decay of tritium. The accumulation of helium, which is virtually insoluble in the copper lattice, can cause the nucleation of cavities along grain boundaries and promote intergranular fracture. Permeation studies have shown that oxide particles act as trap sites for diffusing hydrogen isotopes, and thus may affect the susceptibility of copper to helium-induced degradation by altering the initial tritium distribution in the metal lattice. Tensile and metallographic data demonstrate that oxide particles trap both tritium and helium and decrease the susceptibility of copper to helium-induced intergranular fracture. 25 refs, 3 tabs, 12 figs.

Wheeler, D.A.

1990-12-31

212

In vivo Expression of Inducible Nitric Oxide Synthase in Experimentally Induced Neurologic Diseases  

Microsoft Academic Search

The purpose of this study was to investigate the induction of inducible nitric oxide synthase (iNOS) mRNA in the brain tissue of rats and mice under the following experimental conditions: in rats infected with borna disease virus and rabies virus, in mice infected with herpes simplex virus, and in rats after the induction of experimental allergic encephalitis. The results showed

Hilary Koprowski; Yong Mu Zheng; Ellen Heber-Katz; Nigel Fraser; Lucy Rorke; Zhen Fang Fu; Cathleen Hanlon; Bernhard Dietzschold

1993-01-01

213

Effects of ultrafine particles-induced oxidative stress on Clara cells in allergic lung inflammation  

Microsoft Academic Search

BACKGROUND: Clara cell protein (CC16), the main secretory product of bronchiolar Clara cells, plays an important protective role in the respiratory tract against oxidative stress and inflammation. The purpose of the study was to investigate the role of elemental carbon ultrafine particles (EC-UFP)-induced oxidative stress on Clara cells and CC16 in a mouse model of allergic lung inflammation. METHODS: Ovalbumin

Francesca Alessandrini; Ingrid Weichenmeier; Erik van Miert; Shinji Takenaka; Erwin Karg; Cornelia Blume; Martin Mempel; Holger Schulz; Alfred Bernard; Heidrun Behrendt

2010-01-01

214

Light-induced heterogeneous ozone processing on organic coated particles: Kinetics and condensed-phase products  

Microsoft Academic Search

For the first time we investigated the effect of solar irradiation upon the heterogeneous ozonation of adsorbed 3,4,5-trimethoxybenzaldehyde on solid surface. Light-induced heterogeneous reactions between gas-phase ozone and 3,4,5-trimethoxybenzaldehyde adsorbed on silica particles were performed and the consecutive reaction products were identified. At an ozone mixing ratio of 250 ppb, the loss of 3,4,5-trimethoxybenzaldehyde ranged from 1.0 · 10?6 s?1 in the

Sopheak Net; Sasho Gligorovski; Henri Wortham

2010-01-01

215

Improving diode-laser-induced fluorescence detection of airborne biological particles by exciting multiple biofluorophores  

Microsoft Academic Search

Laser-induced fluorescence provides a real-time technique for detecting airborne pathogens. Discrimination between biological and non-biological particles can be improved by simultaneously testing for more than one of the several common biofluorophores. Typically, this requires excitation with two or more laser wavelengths, considerably increasing the cost, size and complexity of sensors based on mainframe lasers. Recent advances in UV-emitting AlGaN diode

Geoffrey A. Wilson; Richard K. DeFreez

2004-01-01

216

Quantitative analysis of the fluid inclusions by particle-induced gamma-ray emission  

Microsoft Academic Search

The particle-induced gamma-ray emission (PIGE) method, very sensitive for the light elements Li, Be, B, F, Na, is complementary to the PIXE method for the determination of trace elements in complex materials. The deep penetration (more than 50 mm) of 3 MeV protons in light matrices allows heterogenities situated under the irradiated surface of the target to be revealed. This

M. Volfinger

2002-01-01

217

Convective and Diffusive Energetic Particle Losses Induced by Shear Alfven Waves in the ASDEX Upgrade Tokamak  

SciTech Connect

We present here the first phase-space characterization of convective and diffusive energetic particle losses induced by shear Alfven waves in a magnetically confined fusion plasma. While single toroidal Alfven eigenmodes (TAE) and Alfven cascades (AC) eject resonant fast ions in a convective process, an overlapping of AC and TAE spatial structures leads to a large fast-ion diffusion and loss. Diffusive fast-ion losses have been observed with a single TAE above a certain threshold in the fluctuation amplitude.

Garcia-Munoz, M.; Hicks, N.; Bilato, R.; Bobkov, V.; Bruedgam, M.; Fahrbach, H.-U.; Igochine, V.; Maraschek, M.; Sassenberg, K. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association Boltzmannstrasse 2, D-85748 Garching (Germany); Voornveld, R. van [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Classen, I. G. J. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association Boltzmannstrasse 2, D-85748 Garching (Germany); FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Jaemsae, S. [Helsinki University of Technology, Association Euratom-Tekes, P.O. Box 4100, FIN-02015 HUT (Finland)

2010-05-07

218

Histological patterns in drug-induced liver disease.  

PubMed

The diagnosis of drug-induced liver injury (DILI) is a challenging problem, often confounded by incomplete clinical information and the difficulty of eliciting exposure to herbal products, over-the-counter agents and toxins. The task is further rendered difficult on biopsy, as drugs can mimic all the patterns found in primary liver disease. Acute hepatitis, with or without cholestasis, is the most common histological pattern of DILI, and drugs such as acetaminophen are the leading causes of acute liver failure. Most cases of DILI resolve on discontinuation of the drug, but recovery can take months or rarely the disease can progress despite drug withdrawal. Drugs such as methotrexate can lead to chronic hepatitis and cirrhosis, while others such as minocycline, nitrofurantoin and methyldopa are implicated in autoimmune hepatitis. Prolonged cholestasis and ductopenia resembling primary chronic biliary disease can occur. Drug-induced steatohepatitis is also an uncommon pattern, but is well described with drugs such as amiodarone and irinotecan. In the presence of risk factors such as obesity and diabetes, some drugs such as tamoxifen, oestrogens and nifedipine can precipitate or exacerbate steatohepatitis. Other observed patterns include granulomatous hepatitis, vascular injury (eg, sinusoidal obstruction syndrome), Ito cell lipidosis and neoplasms (eg, adenomas). PMID:19474352

Ramachandran, R; Kakar, S

2009-06-01

219

Experimental and statistical investigation of thermally induced failure in reactor fuel particles  

SciTech Connect

An incomplete experimental study into the failure statistics of fuel particle for the high-temperature gas-cooled reactor (HTGR) is described. Fuel particles failure was induced by thermal ramping from room temperature to temperatures in the vicinity of 2273/sup 0/K to 2773/sup 0/K in 2 to 30 h and detected by the appearance of /sup 85/Kr in the helium carrier gas used to sweep the furnace. The concentration of krypton, a beta emitter, was detected by measuring the current that resulted when the helium sweep gas was passed through an ionization chamber. TRISO fuel particles gave a krypton concentration profile as a function of time that built up in several minutes and decayed in a fraction of an hour. This profile, which was temperature independent, was similar to the impulse response of the ionization chamber, suggesting that the TRISO particles failed instantaneously and completely. BISO fuel particles gave a krypton concentration profile as a function of time that built up in a fraction of an hour and decayed in a fraction of a day. This profile was strongly temperature dependent, suggesting that krypton release was diffusion controlled, i.e., that the krypton was diffusing through a sound coat, or that the BISO coating failed but that the krypton was unable to escape the kernel without diffusion, or that a combination of pre- and postfailure diffusion accompanied partial or complete failure.

Lunsford, J.L.; Imprescia, R.J.; Bowman, A.L.; Radosevich, C.E.

1980-10-01

220

Mutilocus genetic determinants of LDL particle size in coronary artery disease families  

SciTech Connect

Recent interest in atherosclerosis has focused on the genetic determinants of low-density lipoprotein (LDL) particle size, because of (1) the association of small dense LDL particles with a three-fold increased risk for coronary artery disease (CAD) and (2) the recent report of linkage of the trait to the LDL receptor (chromosome 19). By utilizing nonparametric quantitative sib-pair and relative-pair-analysis methods in CAD families, we tested for linkage of a gene or genes controlling LDL particle sizes with the genetic loci for the major apolipoproteins and enzymes participating in lipoprotein metabolism. We confirmed evidence for linkage to the LDL receptor locus (P = .008). For six candidate gene loci, including apolipoprotein(apo)B, apoAII, apo(a), apoE-CI-CII, lipoprotein lipase, and high-density lipoprotein-binding protein, no evidence for linkage was observed by sib-pair linkage analyses (P values ranged from .24 to .81). However, in addition, we did find tentative evidence for linkage with the apoAI-CIII-AIV locus (chromosome 11) (P = .06) and significant evidence for linkage of the cholesteryl ester transfer protein locus (chromosome 16) (P = .01) and the manganese superoxide dismutase locus (chromosome 6) (P = .001), thus indicating multilocus determination of this atherogenic trait. 73 refs., 3 figs., 4 tabs.

Rotter, J.I.; Bu, X.; Cantor, R.M. [and others

1996-03-01

221

Mineralogical and geochemical aspects of mineral-induced disease  

SciTech Connect

Many minerals are known to cause disease following inhalation, including asbestos, silica, zeolites, and clays. The mineralogical properties that determine toxicity are not known, hindering effective risk assessment. Consequently, many minerals that do not pose risks are controlled excessively and many minerals that do pose risk remain uncontrolled. The authors are integrating mineralogy and biology in an interdisciplinary scientific investigation of the mechanisms of mineral-induced disease. The biological endpoints include the formation of ferruginous bodies and chemical signaling (e.g., production of cytokines or active oxygen species) by cells; the mineralogical variables include structure, composition, and surface properties. The authors are also determining what information about the biological reaction is preserved in the mineral surface.

Guthrie, G.; Raymond, R.; Saffiotti, U.; Aust, A. [Los Alamos National Lab., NM (United States); Mossman, B. [Univ. of Vermont, Burlington, VT (United States)

1996-04-01

222

Effect of disease-induced mortality on structural network properties  

NASA Astrophysics Data System (ADS)

We study epidemic processes on complex networks, where infected nodes are either removed permanently or they can potentially recover. The process influences the localization of the infection by creating buffered zones, which in turn isolate large parts of the network. We show that there is an interesting interplay between the percentage and location of the removed population with the network structural integrity, even before reaching the critical point of total network disruption. The model can be used to determine the impact of disease-induced mortality to extinction of organisms, where destruction of the social structure can lead to loss of the species ability to recover.

Gallos, Lazaros; Fefferman, Nina

2013-03-01

223

Neonatal jaundice, animal-induced injuries and disease, and immunizations.  

PubMed

The past years' literature on topics of interest to the general practitioner in the areas of neonatal jaundice, animal-induced injury and disease, and immunizations is reviewed. Highlighted are current practice implications of recent publications. As always, the pursuit of excellence in clinical care involves balancing new information with experienced practice. Public health policy, child advocacy, and managed care demands additionally influence the current practice of pediatrics and modify our behavior as pediatricians. However, it is at the bedside that we must strive to provide the most beneficial and compassionate care. PMID:9300206

Gerson, W T

1997-08-01

224

Regulation of hypoxia-inducible factor in kidney disease.  

PubMed

Hypoxia plays a crucial role in the pathophysiology of acute kidney injury (AKI) and presumably also chronic kidney disease (CKD). Hypoxia-inducible factor (HIF) is the master transcription factor that regulates adaptive responses against hypoxia. Under hypoxic conditions, HIF activates target genes with hypoxia-responsive elements in their regulatory regions. The HIF isoforms and regulators of HIF (i.e. prolyl hydroxylases) show cell type-specific distributions. Hypoxia is observed in both ischaemic and so-called non-ischaemic forms of AKI. In addition to the acute phase, hypoxia may ensue during the recovery phase of AKI, possibly due to the oxygen-consuming processes of cell growth and proliferation for repair. Although HIF protects the kidney against AKI, intrinsic HIF activation is submaximal in AKI and further augmentation of HIF ameliorates disease manifestations. The kidney in CKD also suffers from hypoxia caused by multiple mechanisms, including sustained oxygen demands in the remaining nephrons due to maladaptive tubuloglomerular feedback. Whether HIF is chronically upregulated in CKD is contentious. Hypoxia-inducible factor activation is a promising therapeutic approach to CKD, but excessive activation of HIF may be deleterious. It is likely that there is a therapeutic window of HIF activation in chronic conditions. Under certain circumstances, animals with CKD are protected against AKI and this may be explained by non-physiological hypoxia of the kidney and subsequent HIF expression. In addition, an acute hypoxic insult may induce long-lasting changes, possibly including epigenetic modifications induced by HIF. These observations suggest a complex interaction between AKI and CKD via hypoxia and HIF activation. PMID:22905709

Nangaku, Masaomi; Rosenberger, Christian; Heyman, Samuel N; Eckardt, Kai-Uwe

2013-02-01

225

Levodopa-induced dyskinesias in Parkinson's disease: emerging treatments  

PubMed Central

Parkinson’s disease therapy is still focused on the use of L-3,4-dihydroxyphenylalanine (levodopa or L-dopa) for the symptomatic treatment of the main clinical features of the disease, despite intensive pharmacological research in the last few decades. However, regardless of its effectiveness, the long-term use of levodopa causes, in combination with disease progression, the development of motor complications termed levodopa-induced dyskinesias (LIDs). LIDs are the result of profound modifications in the functional organization of the basal ganglia circuitry, possibly related to the chronic and pulsatile stimulation of striatal dopaminergic receptors by levodopa. Hence, for decades the key feature of a potentially effective agent against LIDs has been its ability to ensure more continuous dopaminergic stimulation in the brain. The growing knowledge regarding the pathophysiology of LIDs and the increasing evidence on involvement of nondopaminergic systems raises the possibility of more promising therapeutic approaches in the future. In the current review, we focus on novel therapies for LIDs in Parkinson’s disease, based mainly on agents that interfere with glutamatergic, serotonergic, adenosine, adrenergic, and cholinergic neurotransmission that are currently in testing or clinical development.

Bargiotas, Panagiotis; Konitsiotis, Spyridon

2013-01-01

226

Exposure to Concentrated Ambient Particles Does Not Affect Vascular Function in Patients with Coronary Heart Disease  

PubMed Central

Background Exposure to fine particulate air pollution is associated with increased cardiovascular morbidity and mortality. We previously demonstrated that exposure to dilute diesel exhaust causes vascular dysfunction in humans. Objectives We conducted a study to determine whether exposure to ambient particulate matter causes vascular dysfunction. Methods Twelve male patients with stable coronary heart disease and 12 age-matched volunteers were exposed to concentrated ambient fine and ultrafine particles (CAPs) or filtered air for 2 hr using a randomized, double-blind cross-over study design. We measured peripheral vascular vasomotor and fibrinolytic function, and inflammatory variables—including circulating leukocytes, serum C-reactive protein, and exhaled breath 8-isoprostane and nitrotyrosine—6–8 hr after both exposures. Results Particulate concentrations (mean ± SE) in the exposure chamber (190 ± 37 ?g/m3) were higher than ambient levels (31 ± 8 ?g/m3) and levels in filtered air (0.5 ± 0.4 ?g/m3; p < 0.001). Chemical analysis of CAPs identified low levels of elemental carbon. Exhaled breath 8-isoprostane concentrations increased after exposure to CAPs (16.9 ± 8.5 vs. 4.9 ± 1.2 pg/mL, p < 0.05), but markers of systemic inflammation were largely unchanged. Although there was a dose-dependent increase in blood flow and plasma tissue plasminogen activator release (p < 0.001 for all), CAPs exposure had no effect on vascular function in either group. Conclusions Despite achieving marked increases in particulate matter, exposure to CAPs—low in combustion-derived particles—did not affect vasomotor or fibrinolytic function in either middle-aged healthy volunteers or patients with coronary heart disease. These findings contrast with previous exposures to dilute diesel exhaust and highlight the importance of particle composition in determining the vascular effects of particulate matter in humans.

Mills, Nicholas L.; Robinson, Simon D.; Fokkens, Paul H. B.; Leseman, Daan L. A. C.; Miller, Mark R.; Anderson, David; Freney, Evelyn J.; Heal, Mathew R.; Donovan, Robert J.; Blomberg, Anders; Sandstrom, Thomas; MacNee, William; Boon, Nicholas A.; Donaldson, Ken; Newby, David E.; Cassee, Flemming R.

2008-01-01

227

Clonogenic assay of type a influenza viruses reveals noninfectious cell-killing (apoptosis-inducing) particles.  

PubMed

Clonogenic (single-cell plating) assays were used to define and quantify subpopulations of two genetically closely related variants of influenza virus A/TK/OR/71 that differed primarily in the size of the NS1 gene product; they expressed a full-size (amino acids [aa] 1 to 230) or truncated (aa 1 to 124) NS1 protein. Monolayers of Vero cells were infected with different amounts of virus, monodispersed, and plated. Cell survival curves were generated from the fraction of cells that produced visible colonies as a function of virus multiplicity. The exponential loss of colony-forming capacity at low multiplicities demonstrated that a single virus particle sufficed to kill a cell. The ratios of cell-killing particles (CKP) to plaque-forming particles (PFP) were 1:1 and 7:1 in populations of variants NS1(1-124) and NS1(1-230), respectively. This study revealed a new class of particles in influenza virus populations-noninfectious CKP. Both infectious and noninfectious CKP were 6.3 times more resistant to UV radiation than PFP activity. Based on UV target theory, a functional polymerase subunit was implicated in a rate-limiting step in cell killing. Since influenza viruses kill cells by apoptosis (programmed cell death), CKP are functionally apoptosis-inducing particles. Noninfectious CKP are present in excess of PFP in virus populations with full-size NS1 and induce apoptosis that is temporally delayed and morphologically different than that initiated by infectious CKP present in the virus population expressing truncated NS1. The identification and quantification of both infectious and noninfectious CKP defines new phenotypes in influenza virus populations and presents a challenge to determine their role in regulating infectivity, pathogenesis, and vaccine efficacy. PMID:18184709

Ngunjiri, John M; Sekellick, Margaret J; Marcus, Philip I

2008-01-09

228

Adenosine A2A Receptor Activation Prevents Wear Particle-Induced Osteolysis  

PubMed Central

Prosthesis loosening, associated with wear-particle–induced inflammation and osteoclast-mediated bone destruction, is a common cause for joint implant failure, leading to revision surgery. Adenosine A2A receptors (A2AR) mediate potent anti-inflammatory effects in many tissues and prevent osteoclast differentiation. We tested the hypothesis that an A2AR agonist could reduce osteoclast-mediated bone resorption in a murine calvaria model of wear-particle–induced bone resorption. C57Bl/6 and A2A knockout (A2ARKO) mice received ultrahigh-molecular weight polyethylene particles (UHMWPE) and were treated daily with either saline or the A2AR agonist CGS21680. After 2 weeks, micro-computed tomography of calvaria demonstrated that CGS21680 reduced particle-induced bone pitting and porosity in a dose-dependent manner, increasing cortical bone and bone volume compared to control mice. Histological examination demonstrated diminished inflammation after treatment with CGS21680. In A2AKO mice, CGS21680 did not affect osteoclast-mediated bone resorption or inflammation. Levels of bone-resorption markers receptor activator of nuclear factor-kB (RANK), RANK ligand (RANKL), cathepsin K, CD163, and osteopontin were reduced following CGS21680 treatment, together with a reduction in osteoclasts. Secretion of interleukin 1? (IL-1?) and TNF? was significantly decreased, whereas IL-10 was markedly increased in bone by CGS21680. These results in mice suggest that site-specific delivery of an adenosine A2AR agonist could enhance implant survival, delaying or eliminating the need for revision arthroplastic surgery.

Mediero, Aranzazu; Frenkel, Sally R.; Wilder, Tuere; He, Wenjie; Mazumder, Amitabha; Cronstein, Bruce N.

2012-01-01

229

Light induced toxicity reduction of silver nanoparticles to Tetrahymena Pyriformis: effect of particle size.  

PubMed

As a result of the extensive application of silver nanoparticles (AgNPs), their potential hazards, once they are released into the natural environment, are of great concern to people. Since silver is very sensitive to light, the toxicity of AgNPs released into the natural environment will be inevitably affected by light. The aim of this study was to investigate the relationship between light, toxicity, and particle size of AgNPs and deduce the possible mechanism of any interaction. Our study revealed that there was negative correlation between the particle size and the toxicity: small AgNPs (5-10nm) had higher toxicity than large AgNPs (15-25nm) to Tetrahymena pyriformis (T. pyriformis) under dark condition. Comparing the size dependent AgNPs toxicity under dark and light conditions, the effect of light to size dependent AgNPs toxicity was ascertained. The results indicated that AgNPs toxicity was decreased by light and the most important discovery was that the change of size dependent AgNPs toxicity had significant difference under light irradiation. The decrease of small AgNPs toxicity induced by light was more notable than large AgNPs. The decreased level of cell toxicity for small AgNPs was 32±0.7%, whereas it was only 10.6±5.2% for large AgNPs kept 24h under light irradiation. The further investigation indicated that the above changes induced by light can be attributed to the decrease of released silver ions, particle growth and aggregation of AgNPs under light irradiation. The obtained results showed that the light irradiation can promote the rapid growth of small AgNPs and result in the obvious increase of particle size and serious aggregation. These phenomena would induce the decrease of silver ions released from small AgNPs, which is responsible for the remarkable decrease of toxicity for small AgNPs. PMID:23454310

Shi, Junpeng; Xu, Bin; Sun, Xia; Ma, Chunyan; Yu, Changping; Zhang, Hongwu

2013-02-10

230

A Lagrangian particle model to predict the airborne spread of foot-and-mouth disease virus  

NASA Astrophysics Data System (ADS)

Airborne spread of bioaerosols in the boundary layer over a complex terrain is simulated using a Lagrangian particle model, and applied to modelling the airborne spread of foot-and-mouth disease (FMD) virus. Two case studies are made with study domains located in a hilly region in the northwest of the Styrian capital Graz, the second largest town in Austria. Mountainous terrain as well as inhomogeneous and time varying meteorological conditions prevent from application of so far used Gaussian dispersion models, while the proposed model can handle these realistically. In the model, trajectories of several thousands of particles are computed and the distribution of virus concentration near the ground is calculated. This allows to assess risk of infection areas with respect to animal species of interest, such as cattle, swine or sheep. Meteorological input data like wind field and other variables necessary to compute turbulence were taken from the new pre-operational version of the non-hydrostatic numerical weather prediction model LMK ( Lokal-Modell-Kürzestfrist) running at the German weather service DWD ( Deutscher Wetterdienst). The LMK model provides meteorological parameters with a spatial resolution of about 2.8 km. To account for the spatial resolution of 400 m used by the Lagrangian particle model, the initial wind field is interpolated upon the finer grid by a mass consistent interpolation method. Case studies depict a significant influence of local wind systems on the spread of virus. Higher virus concentrations at the upwind side of the hills and marginal concentrations in the lee are well observable, as well as canalization effects by valleys. The study demonstrates that the Lagrangian particle model is an appropriate tool for risk assessment of airborne spread of virus by taking into account the realistic orographic and meteorological conditions.

Mayer, D.; Reiczigel, J.; Rubel, F.

231

Acute cholestatic liver disease protects against glycerol-induced acute renal failure in the rat  

Microsoft Academic Search

Acute cholestatic liver disease protects against glycerol-induced acute renal failure in the rat.BackgroundIt is widely held that liver disease predisposes toward acute tubular necrosis. The present study examines the effect of acute cholestatic liver disease on the susceptibility to glycerol-induced acute tubular necrosis in the rat.MethodsAcute cholestatic liver disease was induced by ligation of the common bile duct, while the

Nelson Leung; Anthony J. Croatt; Jill J. Haggard; Joseph P. Grande; Karl A. Nath

2001-01-01

232

A bipolar mechanism for alpha-particle-induced soft errors in GaAs integrated circuits  

NASA Astrophysics Data System (ADS)

The alpha-particle-induced collected charge in undoped LEC semi-insulating GaAs is measured in n+-i-n+ and n+-p-n+ isolation structures and is compared with the results of an analytical model based on a bipolar mechnism. In n+-i-n+ isolation structures, a collected-storage multiplication phenomenon induced by alpha-particle incidence is observed. The measured collected charge is about three times the alpha-particle-generated charge. This phenomenon can be attributed to charge transfer between two adjacent n+ regions. The dominant charge-collection process continues for 2.4 ns in n+-i-n+ isolation structures, but in n+-p-n+ isolation structures, it stops within 0.8 ns. The measured collected charge decreases as the isolation gap and background acceptor concentration increase. These experimental results can be explained semiquantitatively by the analytical model. This suggests that the primary mechanism of soft errors in GaAs ICs is a bipolar mechanism.

Umemoto, Yasunari; Matsunaga, Nobutoshi; Mitsusada, Kazumichi

1989-05-01

233

Size distributions of nanoscaled particles and gas temperatures from time-resolved laser-induced-incandescence measurements  

Microsoft Academic Search

Laser-induced-incandescence (LII) signal decays are measured in sooting premixed atmospheric and low-pressure flames. Soot particle temperatures are obtained from LII signals measured at two wavelengths. Soot particle size distributions P(r) and flame temperatures T are measured spatially resolved by independent techniques. Heat and mass transfer kinetics of the LII process are determined from measured soot particle temperatures, flame temperatures, and

Thilo Lehre; Beate Jungfleisch; Rainer Suntz; Henning Bockhorn

2003-01-01

234

Corporation-induced Diseases, Upstream Epidemiologic Surveillance, and Urban Health  

PubMed Central

Corporation-induced diseases are defined as diseases of consumers, workers, or community residents who have been exposed to disease agents contained in corporate products. To study the epidemiology and to guide expanded surveillance of these diseases, a new analytical framework is proposed. This framework is based on the agent–host–environment model and the upstream multilevel epidemiologic approach and posits an epidemiologic cascade starting with government-sanctioned corporate profit making and ending in a social cost, i.e., harm to population health. Each of the framework’s levels addresses a specific level of analysis, including government, corporations, corporate conduits, the environment of the host, and the host. The explained variable at one level is also the explanatory variable at the next lower level. In this way, a causal chain can be followed along the epidemiologic cascade from the site of societal power down to the host. The framework thus describes the pathways by which corporate decisions filter down to disease production in the host and identifies opportunities for epidemiologic surveillance. Since the environment of city dwellers is strongly shaped by corporations that are far upstream and several levels away, the framework has relevance for the study of urban health. Corporations that influence the health of urban populations include developers and financial corporations that determine growth or decay of urban neighborhoods, as well as companies that use strategies based on neighborhood characteristics to sell products that harm consumer health. Epidemiological inquiry and surveillance are necessary at all levels to provide the knowledge needed for action to protect the health of the population. To achieve optimal inquiry and surveillance at the uppermost levels, epidemiologists will have to work with political scientists and other social scientists and to utilize novel sources of information.

2008-01-01

235

Therapeutic application of metallic nanoparticles combined with particle-induced x-ray emission effect  

NASA Astrophysics Data System (ADS)

Metallic nanoparticles (MNP) are able to release localized x-rays when activated with a high energy proton beam by the particle-induced x-ray emission (PIXE) effect. The exploitation of this phenomenon in the therapeutic irradiation of tumors has been investigated. PIXE-based x-ray emission directed at CT26 tumor cells in vitro, when administered with either gold (average diameter 2 and 13 nm) or iron (average diameter 14 nm) nanoparticles (GNP or SNP), increased with MNP solution concentration over the range of 0.1-2 mg ml - 1. With irradiation by a 45 MeV proton therapy (PT) beam, higher concentrations had a decreased cell survival fraction. An in vivo study in CT26 mouse tumor models with tumor regression assay demonstrated significant tumor dose enhancement, thought to be a result of the PIXE effect when compared to conventional PT without MNP (radiation-only group) using a 45 MeV proton beam (p < 0.02). Those receiving GNP or SNP injection doses of 300 mg kg - 1 body weight before proton beam therapy demonstrated 90% or 75% tumor volume reduction (TVR) in 20 days post-PT while the radiation-only group showed only 18% TVR and re-growth of tumor volume after 20 days. Higher complete tumor regression (CTR) was observed in 14-24 days after a single treatment of PT with an average rate of 33-65% for those receiving MNP compared with 25% for the radiation-only group. A lower bound of therapeutic effective MNP concentration range, in vivo, was estimated as 30-79 µg g - 1 tissue for both gold and iron nanoparticles. The tumor dose enhancement may compensate for an increase in entrance dose associated with conventional PT when treating large, solid tumors with a spread-out Bragg peak (SOBP) technique. The use of a combined high energy Bragg peak PT with PIXE generated by MNP, or PIXE alone, may result in new treatment options for infiltrative metastatic tumors and other diffuse inflammatory diseases.

Kim, Jong-Ki; Seo, Seung-Jun; Kim, Ki-Hong; Kim, Tae-Jeong; Chung, Myung-Hwan; Kim, Kye-Ryung; Yang, Tae-Keun

2010-10-01

236

Flow patterns induced by substrata and body morphologies of benthic organisms, and their roles in determining availability of food particles  

Microsoft Academic Search

A physical model, supported by field experiments, predicts that body and substratum morphology of benthic organisms can determine the particle composition encountered by the organisms. The model is based on the velocity gradient of boundary-layer flows, its resultant particle distribution, and the flow pattern induced by bluff bodies (benthic organisms and substrata). The various body morphologies of benthic organisms can

AVIGDOR ABELSON; TOUVIA MILOH; YOSSI LOYA

1993-01-01

237

Recombinant nucleocapsid-like particles from dengue-2 induce functional serotype-specific cell-mediated immunity in mice.  

PubMed

The interplay of different inflammatory cytokines induced during dengue virus infection plays a role in either protection or increased disease severity. In this sense, vaccine strategies incorporating whole virus are able to elicit both functional and pathological responses. Therefore, an ideal tetravalent vaccine candidate against dengue should be focused on serotype-specific sequences. In the present work, a new formulation of nucleocapsid-like particles (NLPs) obtained from the recombinant dengue-2 capsid protein was evaluated in mice to determine the level of protection against homologous and heterologous viral challenge and to measure the cytotoxicity and cytokine-secretion profiles induced upon heterologous viral stimulation. As a result, a significant protection rate was achieved after challenge with lethal dengue-2 virus, which was dependent on CD4(+) and CD8(+) cells. In turn, no protection was observed after heterologous challenge. In accordance, in vitro-stimulated spleen cells from mice immunized with NLPs from the four dengue serotypes showed a serotype-specific response of gamma interferon- and tumour necrosis factor alpha-secreting cells. A similar pattern was detected when spleen cells from dengue-immunized animals were stimulated with the capsid protein. Taking these data together, we can assert that NLPs constitute an attractive vaccine candidate against dengue. They induce a functional immune response mediated by CD4(+) and CD8(+) cells in mice, which is protective against viral challenge. In turn, they are potentially safe due to two important facts: induction of serotype specific cell-mediated immunity and lack of induction of antiviral antibodies. Further studies in non-human primates or humanized mice should be carried out to elucidate the usefulness of the NLPs as a potential vaccine candidate against dengue disease. PMID:22398317

Gil, Lázaro; Bernardo, Lídice; Pavón, Alequis; Izquierdo, Alienys; Valdés, Iris; Lazo, Laura; Marcos, Ernesto; Romero, Yaremis; Guzmán, María G; Guillén, Gerardo; Hermida, Lisset

2012-03-07

238

Transport of particles by a thermally induced gradient of the order parameter in nematic liquid crystals.  

PubMed

We demonstrate manipulation and transport of microparticles and even fluorescent molecules by the thermally induced gradient of the order parameter in the nematic liquid crystal. We use IR light absorption of the tightly focused beam of laser tweezers to heat locally a thin layer of the nematic liquid crystal by several degrees. This creates a spatial gradient of temperature of the nematic liquid crystal over separations of several tens of micrometers. We show that a dipolar colloidal particle is attracted into the hot spot of the laser tweezers. The depth of the trapping potential scales linearly with particle radius, indicating that the trapping mechanism is due to elastic self-energy of the distorted nematic liquid crystal around the particle and softening of the elasticity with increased temperature of the liquid crystal. We also demonstrate that this thermal trapping mechanism is efficient down to the nanoscale, as fluorescent molecules are also transported into hotter regions of the liquid crystal. This effect is absent in the isotropic phase, which calls into question particle transport due to the Soret effect. PMID:23848699

Škarabot, M; Lokar, Ž; Muševi?, I

2013-06-03

239

Parkinson's disease induced pluripotent stem cells with triplication of the alpha-synuclein locus  

Microsoft Academic Search

A major barrier to research on Parkinson's disease is inaccessibility of diseased tissue for study. One solution is to derive induced pluripotent stem cells from patients and differentiate them into neurons affected by disease. Triplication of SNCA, encoding alpha-synuclein, causes a fully penetrant, aggressive form of Parkinson's disease with dementia. alpha-Synuclein dysfunction is the critical pathogenic event in Parkinson's disease,

Michael J. Devine; Mina Ryten; Petr Vodicka; Alison J. Thomson; Tom Burdon; Henry Houlden; Fatima Cavaleri; Masumi Nagano; Nicola J. Drummond; Jan-Willem Taanman; Anthony H. Schapira; Katrina Gwinn; John Hardy; Patrick A. Lewis; Tilo Kunath

2011-01-01

240

Elevated sodium chloride concentrations enhance the bystander effects induced by low dose alpha-particle irradiation.  

PubMed

Previous studies have shown that high NaCl can be genotoxic, either alone or combined with irradiation. However, little is known about the relationship between environmental NaCl at elevated conditions and radiation-induced bystander effects (RIBE). RIBE, which has been considered as non-targeted bystander responses, has been demonstrated to occur widely in various cell lines. In the present study, RIBE under the elevated NaCl culture condition was assessed in AG 1522 cells by both the induction of gamma-H2AX, a reliable marker of DNA double-strand break (DSB) for the early process (<1h post irradiation), and the generation of micronuclei (MN), a sensitive marker for relative long process of RIBE. Our results showed that in the absence of irradiation, NaCl at elevated concentration such as 8.0, 9.0 and 10.0g/L did not significantly increase the frequency of gamma-H2AX foci-positive cells and the number of foci per positive cell comparing with that NaCl at a normal concentration (6.8g/L). However, with 0.2cGy alpha-particle irradiation, the induced fraction of gamma-H2AX foci-positive cells and the number of induced gamma-H2AX foci per positive cell were significantly increased in both irradiated and adjacent non-irradiated regions. Similarly, the induction of MN by 0.2cGy alpha-particle irradiation also increased with the elevated NaCl concentrations. With N(G)-methyl-l-arginine, an inhibitor of nitric oxide synthase, the induced fraction of foci-positive cells was effectively inhibited both in 0.2cGy alpha-particle irradiated and adjacent non-irradiated regions under either normal or elevated NaCl conditions. These results suggested that the cultures with elevated NaCl medium magnified the damage effects induced by the low dose alpha-particle irradiation and nitric oxide generated by irradiation was also very important in this process. PMID:17560616

Han, Wei; Zhu, Lingyan; Jiang, Erkang; Wang, Jun; Chen, Shaopeng; Bao, Linzhi; Zhao, Ye; Xu, An; Yu, Zengliang; Wu, Lijun

2007-05-05

241

In vivo Expression of Inducible Nitric Oxide Synthase in Experimentally Induced Neurologic Diseases  

NASA Astrophysics Data System (ADS)

The purpose of this study was to investigate the induction of inducible nitric oxide synthase (iNOS) mRNA in the brain tissue of rats and mice under the following experimental conditions: in rats infected with borna disease virus and rabies virus, in mice infected with herpes simplex virus, and in rats after the induction of experimental allergic encephalitis. The results showed that iNOS mRNA, normally nondetectable in the brain, was present in animals after viral infection or after induction of experimental allergic encephalitis. The induction of iNOS mRNA coincided with the severity of clinical signs and in some cases with the presence of inflammatory cells in the brain. The results indicate that nitric oxide produced by cells induced by iNOS may be the toxic factor accounting for cell damage and this may open the door to approaches to the study of the pathogenesis of neurological diseases.

Koprowski, Hilary; Zheng, Yong Mu; Heber-Katz, Ellen; Fraser, Nigel; Rorke, Lucy; Fu, Zhen Fang; Hanlon, Cathleen; Dietzschold, Bernhard

1993-04-01

242

Heat-induced versus particle-beam-induced chemistry in polyimide  

NASA Astrophysics Data System (ADS)

In the present paper the relationship between chemical reactions and energy deposition mechanisms is investigated for PMDA-ODA thin films. The chemical reactions at the polymer surface and near-surface are studied by XPS technique. The effects induced by using 5 keV Ar0 and 3 keV electrons are compared with those produced by heat treatments up to about 1000°C. In particular, we found that Ar0 bombardment induces some simultaneous chemical mechanisms of decomposition, involving the random destruction of the monomer units. A specific reaction involving recoiling oxygen atoms has been identified. Contrary to this, the deposition of the same amount of total energy by electron irradiation seems to induce only one decomposition mechanism, consisting in the elimination of the whole imidic ring. Finally, thermal pyrolysis promotes several consecutive reactions, mainly involving decarbonylation of the imidic rings, while the phenyl rings and the ether linkages are relatively stable. The experiments show the existence of recognizable ``nonconventional'' chemical reactivity, whose character, in this case, seems mainly related to the collisional term of the energy loss.

Marletta, Giovanni; Iacona, Fabio

1993-06-01

243

Inactivating Icmt ameliorates K-RAS-induced myeloproliferative disease  

PubMed Central

Hyperactive signaling through the RAS proteins is involved in the pathogenesis of many forms of cancer. The RAS proteins and many other intracellular signaling proteins are either farnesylated or geranylgeranylated at a carboxyl-terminal cysteine. That isoprenylcysteine is then carboxyl methylated by isoprenylcysteine carboxyl methyltransferase (ICMT). We previously showed that inactivation of Icmt mislocalizes the RAS proteins away from the plasma membrane and blocks RAS transformation of mouse fibroblasts, suggesting that ICMT could be a therapeutic target. However, nothing is known about the impact of inhibiting ICMT on the development of malignancies in vivo. In the current study, we tested the hypothesis that inactivation of Icmt would inhibit the development or progression of a K-RAS–induced myeloproliferative disease in mice. We found that inactivating Icmt reduced splenomegaly, the number of immature myeloid cells in peripheral blood, and tissue infiltration by myeloid cells. Moreover, in the absence of Icmt, the ability of K-RAS–expressing hematopoietic cells to form colonies in methylcellulose without exogenous growth factors was reduced dramatically. Finally, inactivating Icmt reduced lung tumor development and myeloproliferation phenotypes in a mouse model of K-RAS–induced cancer. We conclude that inactivation of Icmt ameliorates phenotypes of K-RAS–induced malignancies in vivo.

Wahlstrom, Annika M.; Cutts, Briony A.; Liu, Meng; Lindskog, Annika; Karlsson, Christin; Sjogren, Anna-Karin M.; Andersson, Karin M. E.; Young, Stephen G.

2008-01-01

244

CAG expansion induces nucleolar stress in polyglutamine diseases  

PubMed Central

The cell nucleus is a major site for polyglutamine (polyQ) toxicity, but the underlying mechanisms involved have yet been fully elucidated. Here, we report that mutant RNAs that carry an expanded CAG repeat (expanded CAG RNAs) induce apoptosis by activating the nucleolar stress pathway in both polyQ patients and transgenic animal disease models. We showed that expanded CAG RNAs interacted directly with nucleolin (NCL), a protein that regulates rRNA transcription. Such RNA–protein interaction deprived NCL of binding to upstream control element (UCE) of the rRNA promoter, which resulted in UCE DNA hypermethylation and subsequently perturbation of rRNA transcription. The down-regulation of rRNA transcription induced nucleolar stress and provoked apoptosis by promoting physical interaction between ribosomal proteins and MDM2. Consequently, p53 protein was found to be stabilized in cells and became concentrated in the mitochondria. Finally, we showed that mitochondrial p53 disrupted the interaction between the antiapoptotic protein, Bcl-xL, and the proapoptotic protein, Bak, which then caused cytochrome c release and caspase activation. Our work provides in vivo evidence that expanded CAG RNAs trigger nucleolar stress and induce apoptosis via p53 and describes a polyQ pathogenic mechanism that involves the nucleolus.

Tsoi, Ho; Lau, Terrence Chi-Kong; Tsang, Suk-Ying; Lau, Kwok-Fai; Chan, Ho Yin Edwin

2012-01-01

245

Disease-Dependent Local IL-10 Production Ameliorates Collagen Induced Arthritis in Mice  

PubMed Central

Rheumatoid arthritis (RA) is a chronic destructive autoimmune disease characterised by periods of flare and remission. Today’s treatment is based on continuous immunosuppression irrespective of the patient’s inflammatory status. When the disease is in remission the therapy is withdrawn but withdrawal attempts often results in inflammatory flares, and re-start of the therapy is commenced when the inflammation again is prominent which leads both to suffering and increased risk of tissue destruction. An attractive alternative treatment would provide a disease-regulated therapy that offers increased anti-inflammatory effect during flares and is inactive during periods of remission. To explore this concept we expressed the immunoregulatory cytokine interleukin (IL)-10 gene under the control of an inflammation dependent promoter in a mouse model of RA - collagen type II (CII) induced arthritis (CIA). Haematopoetic stem cells (HSCs) were transduced with lentiviral particles encoding the IL-10 gene (LNT-IL-10), or a green fluorescence protein (GFP) as control gene (LNT-GFP), driven by the inflammation-dependent IL-1/IL-6 promoter. Twelve weeks after transplantation of transduced HSCs into DBA/1 mice, CIA was induced. We found that LNT-IL-10 mice developed a reduced severity of arthritis compared to controls. The LNT-IL-10 mice exhibited both increased mRNA expression levels of IL-10 as well as increased amount of IL-10 produced by B cells and non-B APCs locally in the lymph nodes compared to controls. These findings were accompanied by increased mRNA expression of the IL-10 induced suppressor of cytokine signalling 1 (SOCS1) in lymph nodes and a decrease in the serum protein levels of IL-6. We also found a decrease in both frequency and number of B cells and serum levels of anti-CII antibodies. Thus, inflammation-dependent IL-10 therapy suppresses experimental autoimmune arthritis and is a promising candidate in the development of novel treatments for RA.

Jirholt, Pernilla; Tengvall, Sara; Lidberg, Ulf; van den Berg, Wim B.; van de Loo, Fons A.; Gjertsson, Inger

2012-01-01

246

Numerical analysis of heavy ion particle-induced CMOS latch-up  

NASA Astrophysics Data System (ADS)

Assuming a two-dimensional spreading of a sheet of a charge in a plane, a two-dimensional transient numerical simulator is used to analyze heavy ion particle-induced CMOS latch-up. The charge funneling effect during the carrier collection process is found to lower the parasitic bipolar emitter-base potential barrier, which is the main factor initiating latch-up. Latch-up susceptibility is examined as a parameter of the heavy ion particle incident condition, with track lengths taken as 8 microns. The incident conditions demonstrating long path length in the N-well/P-sub junction depletion layer were shown to be the most sensitive to latch-up, and the use of an n+ guard band was found to be more effective for latch-up immunity. The study has LSI space applications.

Aoki, T.; Kasai, R.; Tomizawa, M.

1986-05-01

247

Disease-corrected hepatocyte-like cells from familial hypercholesterolemia-induced pluripotent stem cells.  

PubMed

The generation of human induced pluripotent stem cells (hiPSCs) from an individual patient provides a unique tool for disease modeling, drug discovery, and cell replacement therapies. Patient-specific pluripotent stem cells can be expanded in vitro and are thus suitable for genetic manipulations. To date, several genetic liver disorders have been modeled using patient-specific hiPSCs. Here, we present the generation of corrected hepatocyte-like cells (HLCs) from hiPSCs of a familial hypercholesterolemia (FH) patient with a homozygous mutation in the low-density lipoprotein receptor (LDLR) gene. We generated hiPSCs from a patient with FH with the mutated gene encoding a truncated non-functional receptor. In order to deliver normal LDLR to the defective cells, we used a plasmid vector carrying the normal receptor ORF to genetically transform the hiPSCs. The transformed cells were expanded and directed toward HLCs. Undifferentiated defective hiPSCs and HLCs differentiated from the defective hiPSCs did not have the ability to uptake labeled low-density lipoprotein (LDL) particles. The differentiated transformed hiPSCs showed LDL-uptake ability and the correction of disease phenotype as well as expressions of hepatocyte-specific markers. The functionality of differentiated cells was also confirmed by indo-cyanine green (ICG) uptake assay, PAS staining, inducible cyp450 activity, and oil red staining. These data suggest that hiPSC technology can be used for generation of disease-corrected, patient-specific HLCs with potential value for disease modeling and drug discovery as well as cell therapy applications in future. PMID:23247991

Fattahi, Faranak; Asgari, Samira; Pournasr, Behshad; Seifinejad, Ali; Totonchi, Mehdi; Taei, Adeleh; Aghdami, Nasser; Salekdeh, Ghasem Hosseini; Baharvand, Hossein

2013-07-01

248

CURRENT AND FUTURE STRATEGIES FOR CONTROL OF VIRUS-INDUCED NEOPLASTIC DISEASES OF POULTRY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Virus-induced neoplastic diseases of poultry, namely Marek's disease (MD), induced by a herpesvirus, and the avian leukoses and reticuloendotheliosis induced by retroviruses can cause significant economic losses from tumor mortality as well as poor performance. Successful control of MD is and has b...

249

Infliximab treatment induces apoptosis of lamina propria T lymphocytes in Crohn's disease  

Microsoft Academic Search

Background and aims: Treatment with infliximab induces remission in about 70% of patients with steroid refractory Crohn's disease. Because Crohn's disease is considered to be mediated by uncontrolled activation of mucosal T lymphocytes, we hypothesised that infliximab could induce apoptosis of T lymphocytes.Methods: Induction of apoptosis in vivo was studied in 10 patients with therapy refractory Crohn's disease. In vitro,

T ten Hove; C van Montfrans; M. P. Peppelenbosch; S J H van Deventer

2002-01-01

250

Long-term changes in amphetamine-induced reinforcement and aversion in rats following exposure to 56Fe particle  

NASA Astrophysics Data System (ADS)

Exposing rats to heavy particles produces alterations in the functioning of dopaminergic neurons and in the behaviors that depend upon the integrity of the dopaminergic system. Two of these dopamine-dependent behaviors include amphetamine-induced reinforcement, measure using the conditioned place preference procedure, and amphetamine-induced reinforcement, measured using the conditioned place preference procedure, and amphetamine-induced aversion, measured using the conditioned taste aversion. Previous research has shown that exposing rats to 1.0 Gy of 1GeV/n 56Fe particles produced a disruption of an amphetamine-induced taste aversion 3 days following exposure, but produced an apparent enhancement of the aversion 112 days following exposure. The present experiments were designed to provide a further evaluation of these results by examining taste aversion learning 154 days following exposure to 1.0Gy 56Fe particles and to establish the convergent validity of the taste aversion results by looking at the effects of exposure on the establishment of an amphetamine-induced conditioned place preference 3, 7, and 16 weeks following irradiation. The taste aversion results failed to confirm the apparent enhancement of the amphetamine-induced CTA observed in the prior experiment. However, exposure to 56Fe particles prevented the acquisition of amphetamine-induced place preference at all three-time intervals. The results are interpreted as indicating that exposure to heavy particles can produce long-term changes in behavioral functioning.

Rabin, B. M.; Joseph, J. A.; Shukitt-Hale, B.

251

Immunization with thyroglobulin induces Graves'-like disease in mice.  

PubMed

We immunized AKR/N mice with bovine thyroglobulin (Tg) once every 2 weeks and monitored their time-dependent changes in (125)I uptake activity in the thyroid glands. After 3 months, anti-Tg antibody was positive in all sera from the immunized mice. Serum free tri-iodothyronine (T(3)) and free thyroxine (T(4)) levels in the immunized mice (n=6) were significantly higher than those in the saline injected (control) mice (n=6). Neck counts as well as scintigraphy of the thyroid glands revealed that iodide uptake activity of the immunized mice was not suppressed, but was instead higher than that of the control mice. Two of the six immunized mice showed extremely high iodide uptake activity. The thyroid glands of these two mice were diffusely enlarged and the height of the epithelial cells was also increased. In addition, two mice with high iodide uptake activity produced a high titer of thyroid-stimulating antibody. Additional experiments showed that 4 out of 11 AKR/N mice and 3 out of 10 C57BL6 mice immunized with Tg had high serum free T(3)/free T(4) levels, high (125)I uptake activity of the thyroid, and positive thyroid-stimulating antibody activity. Diffuse goiter, thyrotoxicosis, high iodide uptake activity, and positive thyroid-stimulating antibody are the characteristics of Graves' disease. Thus, these mice exhibit the symptoms of Graves' disease. These results suggest that immunization with Tg induces Graves'-like disease in mice and that our methods will provide a new animal model of Graves' disease. PMID:19491147

Endo, Toyoshi; Kobayashi, Tetsuro

2009-06-02

252

Immunization with thyroglobulin induces Graves'-like disease in mice  

PubMed Central

We immunized AKR/N mice with bovine thyroglobulin (Tg) once every 2 weeks and monitored their time-dependent changes in 125I uptake activity in the thyroid glands. After 3 months, anti-Tg antibody was positive in all sera from the immunized mice. Serum free tri-iodothyronine (T3) and free thyroxine (T4) levels in the immunized mice (n=6) were significantly higher than those in the saline injected (control) mice (n=6). Neck counts as well as scintigraphy of the thyroid glands revealed that iodide uptake activity of the immunized mice was not suppressed, but was instead higher than that of the control mice. Two of the six immunized mice showed extremely high iodide uptake activity. The thyroid glands of these two mice were diffusely enlarged and the height of the epithelial cells was also increased. In addition, two mice with high iodide uptake activity produced a high titer of thyroid-stimulating antibody. Additional experiments showed that 4 out of 11 AKR/N mice and 3 out of 10 C57BL6 mice immunized with Tg had high serum free T3/free T4 levels, high 125I uptake activity of the thyroid, and positive thyroid-stimulating antibody activity. Diffuse goiter, thyrotoxicosis, high iodide uptake activity, and positive thyroid-stimulating antibody are the characteristics of Graves' disease. Thus, these mice exhibit the symptoms of Graves' disease. These results suggest that immunization with Tg induces Graves'-like disease in mice and that our methods will provide a new animal model of Graves' disease.

Endo, Toyoshi; Kobayashi, Tetsuro

2009-01-01

253

Mechanisms of action of inhaled fibers, particles and nanoparticles in lung and cardiovascular diseases  

PubMed Central

Background A symposium on the mechanisms of action of inhaled airborne particulate matter (PM), pathogenic particles and fibers such as silica and asbestos, and nanomaterials, defined as synthetic particles or fibers less than 100 nm in diameter, was held on October 27 and 28, 2005, at the Environmental Protection Agency (EPA) Conference Center in Research Triangle Park, North Carolina. The meeting was the eighth in a series of transatlantic conferences first held in Penarth, Wales, at the Medical Research Council Pneumoconiosis Unit (1979), that have fostered long-standing collaborations between researchers in the fields of mineralogy, cell and molecular biology, pathology, toxicology, and environmental/occupational health. Results The goal of this meeting, which was largely supported by a conference grant from the NHLBI, was to assemble a group of clinical and basic research scientists who presented and discussed new data on the mechanistic effects of inhaled particulates on the onset and development of morbidity and mortality in the lung and cardiovascular system. Another outcome of the meeting was the elucidation of a number of host susceptibility factors implicated in adverse health effects associated with inhaled pathogenic particulates. Conclusion New models and data presented supported the paradigm that both genetic and environmental (and occupational) factors affect disease outcomes from inhaled particulates as well as cardiopulmonary responses. These future studies are encouraged to allow the design of appropriate strategies for prevention and treatment of particulate-associated morbidity and mortality, especially in susceptible populations.

Mossman, Brooke T; Borm, Paul J; Castranova, Vincent; Costa, Daniel L; Donaldson, Kenneth; Kleeberger, Steven R

2007-01-01

254

Antibodies from patients with connective tissue diseases bind specific subsets of cellular RNA-protein particles.  

PubMed Central

We characterized the RNA-containing antigens precipitated by sera from 260 patients with positive antinuclear antibodies. 49 individuals, most of whom had systemic lupus erythematosus or Sjögren's syndrome, possessed antibodies that precipitated the previously identified RNP, Sm, Ro, and La antigens either singly or in combinations. These antigens, which are located on discrete sets of small nuclear or cytoplasmic RNA-protein particles, exhibited a number of antigenic interrelationships. One patient's serum recognized a new particle containing a small RNA which we have called Th; it also precipitated the Ro complexes. Other patients with systemic lupus erythematosus, hepatitis B virus infection, juvenile rheumatoid arthritis, myositis, and rheumatoid arthritis had antibodies that precipitated specific subsets of ribosomal RNA and transfer RNA. One patient's serum contained a monoclonal immunoglobulin G that precipitated ribosomes. Most of these antibodies identified antigenic determinants constituted at least in part of protein. The specificity of the proteins bound to particular cellular RNA, probably explains the exquisite precision with which antibodies from rheumatic disease patients discriminate among RNA subsets. Such sera should be useful probes for investigating specific roles that different RNA and RNA-protein complexes play in cellular metabolism. Images

Hardin, J A; Rahn, D R; Shen, C; Lerner, M R; Wolin, S L; Rosa, M D; Steitz, J A

1982-01-01

255

Assembly and Biological and Immunological Properties of Newcastle Disease Virus-Like Particles?  

PubMed Central

Virus-like particles (VLPs) released from avian cells expressing the Newcastle disease virus (NDV) strain AV proteins NP, M, HN (hemagglutinin-neuraminidase), and F were characterized. The VLP-associated HN and F glycoproteins directed the attachment of VLPs to cell surfaces and fusion of VLP membranes with red blood cell membranes, indicating that they were assembled into VLPs in an authentic conformation. These particles were quantitatively prepared and used as an immunogen, without adjuvant, in BALB/c mice. The resulting immune responses, detected by enzyme-linked immunosorbent assay (ELISA), virus neutralization, and intracellular cytokine staining, were comparable to the responses to equivalent amounts of inactivated NDV vaccine virus. HN and F proteins from another strain of NDV, strain B1, could be incorporated into these VLPs. Foreign peptides were incorporated into these VLPs when fused to the NP or HN protein. The ectodomain of a foreign glycoprotein, the Nipah virus G protein, fused to the NDV HN protein cytoplasmic and transmembrane domains was incorporated into ND VLPs. Thus, ND VLPs are a potential NDV vaccine candidate. They may also serve as a platform to construct vaccines for other pathogens.

McGinnes, Lori W.; Pantua, Homer; Laliberte, Jason P.; Gravel, Kathryn A.; Jain, Surbhi; Morrison, Trudy G.

2010-01-01

256

Assembly and biological and immunological properties of Newcastle disease virus-like particles.  

PubMed

Virus-like particles (VLPs) released from avian cells expressing the Newcastle disease virus (NDV) strain AV proteins NP, M, HN (hemagglutinin-neuraminidase), and F were characterized. The VLP-associated HN and F glycoproteins directed the attachment of VLPs to cell surfaces and fusion of VLP membranes with red blood cell membranes, indicating that they were assembled into VLPs in an authentic conformation. These particles were quantitatively prepared and used as an immunogen, without adjuvant, in BALB/c mice. The resulting immune responses, detected by enzyme-linked immunosorbent assay (ELISA), virus neutralization, and intracellular cytokine staining, were comparable to the responses to equivalent amounts of inactivated NDV vaccine virus. HN and F proteins from another strain of NDV, strain B1, could be incorporated into these VLPs. Foreign peptides were incorporated into these VLPs when fused to the NP or HN protein. The ectodomain of a foreign glycoprotein, the Nipah virus G protein, fused to the NDV HN protein cytoplasmic and transmembrane domains was incorporated into ND VLPs. Thus, ND VLPs are a potential NDV vaccine candidate. They may also serve as a platform to construct vaccines for other pathogens. PMID:20181713

McGinnes, Lori W; Pantua, Homer; Laliberte, Jason P; Gravel, Kathryn A; Jain, Surbhi; Morrison, Trudy G

2010-02-24

257

Oral Transmissibility of Prion Disease Is Enhanced by Binding to Soil Particles  

PubMed Central

Soil may serve as an environmental reservoir for prion infectivity and contribute to the horizontal transmission of prion diseases (transmissible spongiform encephalopathies [TSEs]) of sheep, deer, and elk. TSE infectivity can persist in soil for years, and we previously demonstrated that the disease-associated form of the prion protein binds to soil particles and prions adsorbed to the common soil mineral montmorillonite (Mte) retain infectivity following intracerebral inoculation. Here, we assess the oral infectivity of Mte- and soil-bound prions. We establish that prions bound to Mte are orally bioavailable, and that, unexpectedly, binding to Mte significantly enhances disease penetrance and reduces the incubation period relative to unbound agent. Cox proportional hazards modeling revealed that across the doses of TSE agent tested, Mte increased the effective infectious titer by a factor of 680 relative to unbound agent. Oral exposure to Mte-associated prions led to TSE development in experimental animals even at doses too low to produce clinical symptoms in the absence of the mineral. We tested the oral infectivity of prions bound to three whole soils differing in texture, mineralogy, and organic carbon content and found soil-bound prions to be orally infectious. Two of the three soils increased oral transmission of disease, and the infectivity of agent bound to the third organic carbon-rich soil was equivalent to that of unbound agent. Enhanced transmissibility of soil-bound prions may explain the environmental spread of some TSEs despite the presumably low levels shed into the environment. Association of prions with inorganic microparticles represents a novel means by which their oral transmission is enhanced relative to unbound agent.

Johnson, Christopher J; Pedersen, Joel A; Chappell, Rick J; McKenzie, Debbie; Aiken, Judd M

2007-01-01

258

Synergy between particles and nitrogen dioxide on emergency hospital admissions for cardiac diseases in Hong Kong.  

PubMed

BACKGROUND: Ambient air pollution is a complex mixture of particles and gaseous pollutants. Epidemiological studies are moving toward a multipollutant approach, requiring an understanding of possible interactions among the pollutants. We aim to estimate the joint effects of particles with an aerodynamic diameter less than 10?m (PM10) and nitrogen dioxide (NO2) on emergency hospital admissions for cardiac diseases, and to explore the possible interactions between PM10 and NO2. METHODS: We collected daily time series data from 1998 to 2007 on emergency hospital admissions for cardiac diseases in Hong Kong, as well as PM10 and NO2 concentrations. Generalized additive Poisson model was used to examine the relationship between air pollution and hospital admissions. We then used three parallel time series approaches (bivariate response surface model, joint effect model and parametric stratified model) to explore the possible interactions between PM10 and NO2. RESULTS: Results showed the greatest joint effect of PM10 and NO2 on emergency cardiac hospitalizations when PM10 and NO2 concentrations were both at high levels. The effect of PM10 was significantly greatest on the days with high NO2 level, and vice versa. A 10?g/m(3) increase of lag0 PM10 and NO2 was associated with an increase of emergency cardiac hospitalizations by 0.55% (95% CI: 0.29-0.80%) and 1.20% (95% CI: 0.87-1.53%) respectively, when the other pollutant was at high level. CONCLUSIONS: We found consistent synergistic interaction between PM10 and NO2 on emergency cardiac hospitalizations in Hong Kong. These findings contribute to the development of a new paradigm for multipollutant air quality management. PMID:23608392

Yu, Ignatius Tak-Sun; Qiu, Hong; Wang, Xiaorong; Tian, Linwei; Tse, Lap Ah

2013-04-19

259

Analytical Applications Of Particle-Induced X-Ray Emission (PIXE)  

SciTech Connect

In this paper a complex study of the capabilities of Particle-Induced X-ray Emission (PIXE) technique for the determination of major, minor and trace constituents of metallurgical, biological and environmental samples has been done. The elements identified in the metallurgical samples (steels) using PIXE were: K, Ca, V, Cr, Mn, Fe, Co, Cu, Ni, Zn, W, Ga, As, Pb, Mo, Rb, In, Rh, Zr, Pd, Nb, Sn and Sb. In the investigated biological and environmental samples (vegetals leaves, soil and mosses) PIXE analysis allowed determination of: S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, As, Hg and Pb.

Popescu, I. V.; Stihi, C.; Bancuta, A.; Dima, G. ['Valahia' University of Targoviste, Targoviste (Romania); Ene, A. ['Dunarea de Jos' University of Galati, Galati (Romania); Badica, T. ['Horia Hulubei' NIPNE, Bucharest (Romania); Ghisa, V. ['Ovidius' University of Constanta, Constanta (Romania)

2007-04-23

260

Conquer the Challenges: Study of Charged-particle-induced Reactions at Stellar Energies  

SciTech Connect

Charged-particle-induced reactions, such as the (p,{gamma}), ({alpha},{gamma}), ({alpha},p) and heavy ion fusion reactions, play important roles in stellar evolution. Due to the Coulomb barrier penetration effect, the cross sections decrease exponentially as the incident energy approaches the interesting astrophysical energy regions, which makes these experiments very challenging. In this talk, I will discuss two challenging problems in experimental nuclear astrophysics, the {sup 12}C({alpha},{gamma}){sup 16}O reaction and the heavy ion fusion reactions.

Tang Xiaodong; Cerrone, Daniel; Davies, Paul; Martin, Ed; Notani, Masahiro [Department of Physics: University of Notre Dame, Notre Dame, IN 46556 (United States)

2009-03-10

261

Analysis of radiation-induced small Cu particle cluster formation in aqueous CuCl2  

USGS Publications Warehouse

Radition-induced small Cu particle cluster formation in aqueous CuCl2 was analyzed. It was noticed that nearest neighbor distance increased with the increase in the time of irradiation. This showed that the clusters approached the lattice dimension of bulk copper. As the average cluster size approached its bulk dimensions, an increase in the nearest neighbor coordination number was found with the decrease in the surface to volume ratio. Radiolysis of water by incident x-ray beam led to the reduction of copper ions in the solution to themetallic state.

Jayanetti, S.; Mayanovic, R. A.; Anderson, A. J.; Bassett, W. A.; Chou, I. -M.

2001-01-01

262

Fluorine determination in human and animal bones by particle-induced gamma-ray emission  

Microsoft Academic Search

Fluorine was determined in the iliac crest bones of patients and in ribs collected from post-mortem investigations by particle-induced\\u000a gamma-ray emission based on the 19F(p,p??)19F reaction, using 2.0\\/2.5 MeV protons. The results indicate that for 68% of the human samples the F concentration is in the\\u000a range 500–1999 ?g g–1. For comparison purposes fluorine was also determined in some animal

Chaturvedula S. Sastri; Venkatesh Iyengar; Gilbert Blondiaux; Yves Tessier; Hermann Petri; Peter Hoffmann; Namik K. Aras; Vladimir Zaichick; Hugo M. Ortner

2001-01-01

263

Fluorine determination in human and animal bones by particle-induced gamma-ray emission.  

PubMed

Fluorine was determined in the iliac crest bones of patients and in ribs collected from post-mortem investigations by particle-induced gamma-ray emission based on the 19F(p,p'gamma)19F reaction, using 2.0/2.5 MeV protons. The results indicate that for 68% of the human samples the F concentration is in the range 500-1999 microg g(-1). For comparison purposes fluorine was also determined in some animal bones; in some animal tissues lateral profiles of fluorine were measured. PMID:11569877

Sastri, C S; Iyengar, V; Blondiaux, G; Tessier, Y; Petri, H; Hoffmann, P; Aras, N K; Zaichick, V; Ortner, H M

2001-08-01

264

Yangxueqingnao particles inhibit rat vascular smooth muscle cell proliferation induced by lysophosphatidic acid  

Microsoft Academic Search

Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced\\u000a by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation\\u000a end product malondialdehyde (MDA) content of the VSMC were assayed. Results: 1×10?9, 1×10?8, 1×10?7 mol\\/L LPA in a

Cai Wei; Xu Yi; Chen Jun-zhu; Huang Shu-ru; Lu Zhen-ya; Wang Zhan-kun

2005-01-01

265

Experimental Study of the Cross Sections of {alpha}-Particle Induced Reactions on 209Bi  

SciTech Connect

Alpha particle induced reactions for generation of 211At used in therapeutic nuclear medicine and possible contaminants were investigated with the stacked foil activation technique on natural bismuth targets up to E{alpha}=39 MeV. Excitation functions for the reactions 209Bi({alpha},2n)211At, 209Bi({alpha},3n)210At, 209Bi({alpha},x) 210Po obtained from direct alpha emission measurements and gamma spectra from decay products are compared with earlier literature values. Thick target yields have been deduced from the experimental cross sections.

Hermanne, A. [Cyclotron Department, Vrije Universiteit Brussel, Laarbeeklaan 103, B1090 Brussels (Belgium); Tarkanyi, F.; Takacs, S.; Szucs, Z. [Atomki, Hungarian Academy of Sciences, Bem Ter, H4001 Debrecen (Hungary)

2005-05-24

266

MR assessment of iodinated contrast-medium-induced nephropathy in rats using ultrasmall particles of iron oxide.  

PubMed

The purpose of this study was to determine the diagnostic value of ultrasmall particles of iron oxide (USPIO)-enhanced MR imaging at different concentrations to evaluate experimental nephropathy. This study was conducted in 23 uninephrectomized rats using a model of iodinated contrast media-induced renal failure. Eleven rats received selective intra-arterial renal administration of diatrizoate (370 mg I/ml) and were compared to two control groups, including five animals injected with isotonic saline and seven noninjected animals. MR imaging was performed 28 hours after the procedure, including T1- and T2-weighted images before and after intravenous administration of successively 5 mumol Fe/kg and 60 mumol/kg of USPIO. Results were interpreted qualitatively and quantitatively with respect to pathologic data, and differences were studied statistically. The maximal signal intensity decrease was noted in normal kidneys in cortex (-65 +/- 4%) and medulla (-84 +/- 5%) on T2-weighted images after injection of 60 mumol/kg of USPIO. At this dose, diseased kidneys displayed less signal intensity decrease than normal kidneys on T2-weighted images (p = .05). Moreover, qualitative analysis showed that the highest sensitivity and specificity to diagnose kidney involvement were obtained with T2-weighted MR images (75% and 91%, respectively) when 60 mumol/kg of USPIO were used (p < .01). USPIO should be useful for in vivo evaluation of the severity of experimentally induced iodinated contrast media renal impairment in animals. PMID:9039610

Laissy, J P; Benderbous, S; Idée, J M; Chillon, S; Beaufils, H; Schouman-Claeys, E

267

PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES: Laser-Induced Particle Jet and Its Ignition Application in Premixed Combustible Gases  

NASA Astrophysics Data System (ADS)

A hot particle jet is induced as a laser pulse from a free oscillated Nd:YAG laser focused on a coal target. The particle jet successfully initiates combustion in a premixed combustible gas consisting of hydrogen, oxygen, and air. The experiment reveals that the ionization of the particle jet is enhanced during the laser pulse. This characteristic is attributed to the electron cascade process and the ionization of the particles or molecules of the target. The initial free electrons, which are ablated from the coal target, are accelerated by the laser pulse through the inverse Bremsstrahlung process and then collide with the neutrals in the jet, causing the latter to be ionized.

Yang, Qian-Suo; Liu, Chun; Peng, Zhi-Min; Zhu, Nai-Yi

2009-06-01

268

M-FISH analysis shows that complex chromosome aberrations induced by ?-particle tracks are cumulative products of localized rearrangements  

PubMed Central

Complex chromosome aberrations are characteristically induced after exposure to low doses of densely ionizing radiation, but little is understood about their formation. To address this issue, we irradiated human peripheral blood lymphocytes in vitro with 0.5 Gy densely ionizing ?-particles (mean of 1 ?-particle/cell) and analyzed the chromosome aberrations produced by using 24-color multiplex fluorescence in situ hybridization (M-FISH). Our data suggest that complex formation is a consequence of direct nuclear ?-particle traversal and show that the likely product of illegitimate repair of damage from a single ?-particle is a single complex exchange. From an assessment of the “cycle structure” of each complex exchange we predict ?-particle-induced damage to be repaired at specific localized sites, and complexes to be formed as cumulative products of this repair.

Anderson, Rhona M.; Stevens, David L.; Goodhead, Dudley T.

2002-01-01

269

Effect of vitamin C and iron chelation on diesel exhaust particle and carbon black induced oxidative damage and cell adhesion molecule expression in human endothelial cells.  

PubMed

Exposure to particulate matter is associated with oxidative stress and risk of cardiovascular diseases. We investigated if vitamin C and desferrioxamine (iron chelator) altered the levels of oxidative stress and expression of cell adhesion molecules upon exposure to diesel exhaust particles (DEP) and carbon black in cultured human umbilical vein endothelial cells (HUVECs). We found that the particles were only slightly cytotoxic in the high concentration ranges. Particle-induced intracellular reactive oxygen species (ROS) production was attenuated by vitamin C administration or iron chelation and particularly when combined (p<0.001). Only desferrioxamine protected the DNA from oxidative damage in terms of strand breaks and formamidopyrimidine DNA glycosylase sensitive sites induced by carbon black (p<0.01). Carbon black and small sized DEP generated from an Euro4 engine increased the surface expression of VCAM-1 and ICAM-1, whereas DEP from an engine representing an old combustion type engine (SRM2975) with larger particles did not affect the expression of cell adhesion molecules. These effects were also attenuated by desferrioxamine but not vitamin C. The study shows that exposure to carbon black and DEP in HUVECs can generate both oxidative stress and expression of cell surface adhesion molecules and that these effects can in part be attenuated by vitamin C and desferrioxamine. PMID:21421028

Frikke-Schmidt, Henriette; Roursgaard, Martin; Lykkesfeldt, Jens; Loft, Steffen; Nøjgaard, Jacob Klenø; Møller, Peter

2011-03-21

270

[Disinhibitory abnormal behavior induced by treatment of Parkinson disease].  

PubMed

The treatment of Parkinson disease has considerably progressed in the last 20 years. However, such treatments results in the adverse event of disinhibitory abnormal behavior, which includes impulse control disorders, punding, and dopamine dysregulation syndrome. Pathological gambling is the most extensively studied among such abnormal behaviors. It has been associated with the use of dopamine agonists and its prevalence increases according to the does of the drugs. The maximum dose of the ergot dopamine agonist pergolide is 1.25 mg/day in Japan, which is a quarter of that used in Western countries. The maximum dose of the non-ergot dopamine agonist, pramipexole is 4.5 mg/day in Japan, which is the same as in Western countries. Pramipexole was launched in 2004 in Japan, and since then cases of pathological gambling associated with dopamine agonists used has been increasing. Because of the excellent health-care system in Japan, patients can easily acquire expensive dopamine agonists. Although the prevalence of these abnormal behaviors has not been studied in Japan, it could be highly proportionate to the amount of dopamine agonists. Disinhibitory abnormal behavior is also induced by deep brain stimulation of the subthalamic nucleus. This technology was approved in 2000 in Japan. The mechanisms by which these behaviors are induced are different between dopamine replacement therapy and deep brain stimulation. Parkinson disease patients and their caregivers occasionally believe the disinhibitory abnormal behavior as arising from the original personality of the patient rather than as an adverse event of treatment. Neurologists should be aware of the occurrence of disinhibitory abnormal behavior in the clinical practice. PMID:22481510

Fujimoto, Ken-Ichi

2012-04-01

271

Castration induces Parkinson disease pathologies in young male mice via inducible nitric-oxide synthase.  

PubMed

Although Parkinson disease (PD) is a progressive neurodegenerative disorder, available animal models do not exhibit irreversible neurodegeneration, and this is a major obstacle in finding out an effective drug against this disease. Here we delineate a new irreversible model to study PD pathogenesis. The model is based on simple castration of young male mice. Levels of inducible nitric-oxide synthase (iNOS), glial markers (glial fibrillary acidic protein and CD11b), and ?-synuclein were higher in nigra of castrated male mice than normal male mice. On the other hand, after castration, the level of glial-derived neurotrophic factor (GDNF) markedly decreased in the nigra of male mice. Accordingly, castration also induced the loss of tyrosine hydroxylase-positive neurons in the nigra and decrease in tyrosine hydroxylase-positive fibers and neurotransmitters in the striatum. Reversal of nigrostriatal pathologies in castrated male mice by subcutaneous implantation of 5?-dihydrotestosterone pellets validates an important role of male sex hormone in castration-induced nigrostriatal pathology. Interestingly, castration was unable to cause glial activation, decrease nigral GDNF, augment the death of nigral dopaminergic neurons, induce the loss of striatal fibers, and impair neurotransmitters in iNOS(-/-) male mice. Furthermore, we demonstrate that iNOS-derived NO is responsible for decreased expression of GDNF in activated astrocytes. Together, our results suggest that castration induces nigrostriatal pathologies via iNOS-mediated decrease in GDNF. These results are important because castrated young male mice may be used as a simple, toxin-free, and nontransgenic animal model to study PD-related nigrostriatal pathologies, paving the way for easy drug screening against PD. PMID:23744073

Khasnavis, Saurabh; Ghosh, Anamitra; Roy, Avik; Pahan, Kalipada

2013-06-06

272

The Endotoxin-Induced Neuroinflammation Model of Parkinson's Disease  

PubMed Central

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the progressive loss of dopaminergic (DA) neurons in the substantia nigra. Although the exact cause of the dopaminergic neurodegeneration remains elusive, recent postmortem and experimental studies have revealed an essential role for neuroinflammation that is initiated and driven by activated microglial and infiltrated peripheral immune cells and their neurotoxic products (such as proinflammatory cytokines, reactive oxygen species, and nitric oxide) in the pathogenesis of PD. A bacterial endotoxin-based experimental model of PD has been established, representing a purely inflammation-driven animal model for the induction of nigrostriatal dopaminergic neurodegeneration. This model, by itself or together with genetic and toxin-based animal models, provides an important tool to delineate the precise mechanisms of neuroinflammation-mediated dopaminergic neuron loss. Here, we review the characteristics of this model and the contribution of neuroinflammatory processes, induced by the in vivo administration of bacterial endotoxin, to neurodegeneration. Furthermore, we summarize the recent experimental therapeutic strategies targeting endotoxin-induced neuroinflammation to elicit neuroprotection in the nigrostriatal dopaminergic system. The potential of the endotoxin-based PD model in the development of an early-stage specific diagnostic biomarker is also emphasized.

Tufekci, Kemal Ugur; Genc, Sermin; Genc, Kursad

2011-01-01

273

Study of fishbone instabilities induced by energetic particles in tokamak plasmas  

NASA Astrophysics Data System (ADS)

Fishbone instabilities, driven by trapped and barely passing energetic particles (EPs), including electrons and ions (EEs or EIs), are numerically studied with the spatial distribution of EPs taken into account. The dispersion relations of the modes are derived for slowing-down and Maxwellian models of EP energy distribution. It is found that the modes with frequency comparable to the toroidal precession frequency ?d of EPs are resonantly excited. Electron and ion fishbone modes share the same growth rates and real frequencies but rotate in opposite directions. The frequency of the modes is found to be higher in the case of near-axis heating than that of off-axis heating. The fishbone instabilities can only be excited by barely trapped or barely passing and deeply trapped particles in positive and negative spatial density gradient regions, respectively. In addition, the most interesting feature of the fishbone modes induced by barely passing particles is that there exists a second stable regime in the higher ?h (pressure of EPs/toroidal magnetic pressure) region, and the modes exist in the range of ?th1 < ?h < ?th2 (?th is threshold or critical beta of EPs) only. The results are well confirmed with Nyquist technology. The possible physical mechanism for the existence of the second stable regime is discussed.

He, H. D.; Dong, J. Q.; Fu, G. Y.; He, Z. X.; Jiang, H. B.; Wang, Z. T.; Zheng, G. Y.; Liu, F.; Long, Y. X.; Shen, Y.; Wang, L. F.

2011-11-01

274

Flow-induced translocation of polymers through a fluidic channel: A dissipative particle dynamics simulation study  

NASA Astrophysics Data System (ADS)

The dynamics of flow-induced translocation of polymers through a fluidic channel has been studied by dissipative particle dynamics (DPD) approach. Unlike implicit solvent models, the many-body energetic and hydrodynamic interactions are preserved naturally by incorporating explicit solvent particles in this approach. The no-slip wall boundary and the adaptive boundary conditions have been implemented in the modified DPD approach to model the hydrodynamic flow within a specific wall structure of fluidic channel and control the particles' density fluctuations. The results show that the average translocation time versus polymer chain length satisfies a power-law scaling of ? ~N1.152. The conformational changes and translocation dynamics of polymers through the fluidic channel have also been investigated in our simulations, and two different translocation processes, i.e., the single-file and double-folded translocation events, have been observed in detail. These findings may be helpful in understanding the conformational and dynamic behaviors of such polymer and/or DNA molecules during the translocation processes.

Guo, Jiayi; Li, Xuejin; Liu, Yuan; Liang, Haojun

2011-04-01

275

Influence of 70 nm silica particles in mice with cisplatin or paraquat-induced toxicity.  

PubMed

In the pharmaceutical industry, nano-size materials are designed as drug carriers and diagnosis probes. Interactions between nano-size materials and chemicals need investigating. Here, we investigated whether nano-size materials affect chemical-induced toxicity using silica particles, which have been widely used in cosmetics and drug delivery and have diameters of 70 (SP70), 300 (SP300) and 1000 (SP1000) nm, a popular anti-tumor agent, cisplatin, and a widely used herbicide, paraquat. Mice were treated with either cisplatin (100 micromol/kg, intraperitoneally) or paraquat (50 mg/kg, intraperitoneally), with or without intravenous silica particle administration. All treatments were non-lethal and did not show severe toxicity, except for injection with both cisplatin and SP70, which were lethal. When mice received with paraquat and/or the silica particles, synergistic enhanced toxicity was observed in both paraquat- and SP70-treated mice. These synergic effects were not observed with either Si300 or 1000 treatment. Our findings suggest that further evaluation on the interaction between nano-size materials and chemicals is critical for the pharmaceutical application of nanotechnology. PMID:19618677

Nishimori, H; Kondoh, M; Isoda, K; Tsunoda, S; Tsutsumi, Y; Yagi, K

2009-06-01

276

Structural brain plasticity in Parkinson's disease induced by balance training.  

PubMed

We investigated morphometric brain changes in patients with Parkinson's disease (PD) that are associated with balance training. A total of 20 patients and 16 healthy matched controls learned a balance task over a period of 6 weeks. Balance testing and structural magnetic resonance imaging were performed before and after 2, 4, and 6 training weeks. Balance performance was re-evaluated after ?20 months. Balance training resulted in performance improvements in both groups. Voxel-based morphometry revealed learning-dependent gray matter changes in the left hippocampus in healthy controls. In PD patients, performance improvements were correlated with gray matter changes in the right anterior precuneus, left inferior parietal cortex, left ventral premotor cortex, bilateral anterior cingulate cortex, and left middle temporal gyrus. Furthermore, a TIME × GROUP interaction analysis revealed time-dependent gray matter changes in the right cerebellum. Our results highlight training-induced balance improvements in PD patients that may be associated with specific patterns of structural brain plasticity. In summary, we provide novel evidence for the capacity of the human brain to undergo learning-related structural plasticity even in a pathophysiological disease state such as in PD. PMID:23916062

Sehm, Bernhard; Taubert, Marco; Conde, Virginia; Weise, David; Classen, Joseph; Dukart, Juergen; Draganski, Bogdan; Villringer, Arno; Ragert, Patrick

2013-08-01

277

Lymphangiogenesis is induced during development of periodontal disease.  

PubMed

Lymphangiogenesis, the formation of new lymphatics, is associated with chronic inflammation and tissue injury, and its role is to enhance lymphatic flow, immune cell transport, and antigen clearance. It is unknown if lymphangiogenesis takes place during periodontal disease development, and we hypothesized that growth of lymphatic vessels occurs in gingiva during development of periodontitis in mice. Inflammation was induced in gingiva with Porphyromonas gingivalis gavage, and bone resorption was verified after 42 days. Growth of lymphatic and blood vessels was measured after immunofluorescent staining with LYVE-1 and CD31. Expression of vascular endothelial growth factors and 2 inflammatory cytokines was investigated 10 days post-infection. Gingival lymphangiogenesis was found 10 days and 42 days post-infection, but proliferation of vessels was observed only in the shortest observation period. Epithelial expression of vascular growth factors (VEGF) A, C, and D was observed in gingiva, and increased numbers of immune cells expressing VEGF-C were found after infection, along with up-regulation of IL-1? and TNF-? at protein levels. We conclude that lymphangiogenesis takes place in gingiva during periodontal disease development, and that up-regulation of vascular growth factor C in recruited immune cells is likely important for the growth of lymphatic vessels. PMID:21979132

Mkonyi, L E; Bakken, V; Søvik, J B; Mauland, E K; Fristad, I; Barczyk, M M; Bletsa, A; Berggreen, E

2011-10-06

278

Motorcycle exhaust particles augment antigen-induced airway inflammation in BALB/c mice.  

PubMed

Evidence indicates that environment pollutants from fossil fuel combustion compromise the immune system by enhancing allergic reactions and damaging the respiratory tract. This study was performed to investigate the effects of motorcycle exhaust particles (MEP), a major air pollutant especially in the urban areas of Taiwan, on allergen-induced airway inflammatory reactions in lab animals. BALB/c mice were intratracheally instilled with ovalbumin (OVA), MEP, or phosphate-buffered saline, 3 times every 2 wk. Airway hyperresponsiveness was measured in unrestrained mice by barometric plethsmography. Bronchoalveolar lavage fluid (BALF) and serum from treated animals were collected for cytokine and antibody determination by enzyme-linked immunosorbent assay (ELISA). Lung tissue stained with hematoxylin/eosin was examined. Data showed that MEP augmented OVA-induced airway inflammation; characterized by infiltration of eosinophils and neutrophils in BALF and lung tissue inflammation. The combination of OVA and MEP markedly increased interleukin-4 (IL-4), interleukin-5 (IL-5), and tumor necrosis factor-alpha (TNF-alpha) protein levels in BALF. In addition, MEP also augmented OVA-induced rise in OVA-specific immunoglobulin (Ig) G1 and IgE and airway hyperresponsiveness. Pretreated lavage cells with mitogen-activated protein kinase (MAPK) inhibitors showed that TNF-alpha release was significantly inhibited. This study found that MEP augmented antigen-induced allergic airway inflammation and airway hyperresponsiveness through a Th2-dominant pathway. PMID:18246500

Lee, Chen-Chen; Cheng, Yu-Wen; Liao, Jiunn-Wang; Chiang, Bor-Luen; Lai, Yih-Loong; Kang, Jaw-Jou

2008-01-01

279

The effect of flow geometry on shear-induced particle segregation and resuspension  

NASA Astrophysics Data System (ADS)

In this thesis, we investigate through theory and experiment the influence of the flow geometry on various shear-induced migration phenomena such as particle demixing, viscous resuspension and meniscus accumulation for a suspension of rigid, non-colloidal particles. The major focus of this thesis is the elucidation of a particle flux mechanism that has been ignored in the literature in the theoretical calculation of the concentration distribution in shear-induced migration phenomena. This mechanism is the convective flux due to the secondary currents arising from the non-Newtonian rheology of suspensions. Historically, suspensions have been modeled as Newtonian fluids with concentration dependent viscosities when calculating velocity distributions due to the tremendous simplification of the governing equations. The results presented in this thesis, however, demonstrate that it is critical to consider the complete rheology of a concentrated suspension when modeling flows in complex geometries. While the magnitude of the secondary currents is small, in many cases they are the dominant mechanism governing the resulting particle concentration distribution. In chapters 2 through 4, we investigate the impact of these secondary currents on the concentration profiles developed in suspension flow through conduits of arbitrary geometry, and in resuspension flow through a tube. In chapter 5, we examine the radial segregation of particles in the squeeze flow of concentrated suspensions. This flow is identical to that produced in loading suspensions on to a parallel plate viscometer and thus the concentration inhomogeneities generated during the loading phenomenon may play a role in the well known scatter of torque measurements in this system. We develop a criterion in terms of the experimental parameters in a parallel plate experiment for the onset of radial inhomogeneities. In the final investigation reported in this thesis, we develop a theoretical model for describing the droplet distribution in the Poiseuille flow of an emulsion through a tube. We show that the mathematical problem that results from this model is amenable to self-similar analysis via the trial function approach. The self-similar solution so obtained is used to evaluate oscillatory flows as a possible technique for separation of the dispersed phase from suspending fluid.

Ramachandran, Arun

280

Possible observation of light neutron nuclei in the alpha-particle-induced fission of 238U  

NASA Astrophysics Data System (ADS)

Searches for nuclear-stable multineutrons among products originating from the fission of 238U nuclei that is induced by 62-MeV alpha particles were performed by the activation method. The reaction involving the transfer of four neutrons and occurring on the isotope 88Sr, 88Sr( x n, ( x - 4) n)92Sr?92Y, was used to identify nuclear-stable multineutrons. A line at the energy of E = 1384 keV was found in the measured gamma-ray spectra of irradiated samples. This line, together with the measured time dependence of the decrease in its activity, is indicative of the formation of the beta-active nucleus 92Sr. This result was reproduced in repeated measurements. It suggests the possible existence of nuclear-stable multineutrons ( x n) for x ? 6. The differential cross section for the x n yield at an angle of 30° in the alpha-particle-induced fission of 238U was about 6 × 10-2 mb/sr.

Novatsky, B. G.; Nikolsky, E. Yu.; Sakuta, S. B.; Stepanov, D. N.

2012-11-01

281

UHMWPE carrying estradiol to treat the particle-induced osteolysis-Processing and characterizing.  

PubMed

The objective of this study was to explore the possibility of UHMWPE implant used as the drug carrier to treat particle-induced osteolysis. 17beta-estradiol (E2), which had the potential application on osteolysis treatment and the high melting point, was added into UHMWPE powder to produce UHMWPE-E2 composites through hot press processing. The hydrophobicity, crystallinity, mechanical properties, and wear performance of the UHMWPE-E2 were characterized compared with the control UHMWPE. The thermal analysis and Fourier Transform Infrared Spectroscopy results demonstrated that the hot press processing would not alter the functional groups of E2 in this study. There were no significant differences in the hydrophobicity and crystallinity between the UHMWPE-E2 and UHMWPE. The UHMWPE-E2 showed satisfying mechanical properties, including ultimate tensile strength (47.2 +/- 3.6 MPa), yield strength (25.0 +/- 0.6 MPa) and elongation at break (320 +/- 25.5 %), which were similar with the control UHMWPE. The friction coefficients and worn scars were similar between the UHMWPE-E2 and the control UHMWPE. The wear mechanism of the UHMWPE-E2 and UHMWPE both were abrasive wear under dry friction. The UHMWPE-E2 possesses the approving mechanical properties and wear performance compared with the control UHMWPE, which might be used as the potential implanted drug carrier to prevent the particle-induced osteolysis in joint replacements. PMID:18563828

Liu, Aiqin; Qu, Shuxin; Chao, Mengmeng; Zhu, Minhao; Weng, Jie; Zhou, Zhongrong

2009-08-01

282

Lung fibrosis induced by crystalline silica particles is uncoupled from lung inflammation in NMRI mice.  

PubMed

Previous studies in rats have suggested a causal relationship between progressive pulmonary inflammation and lung fibrosis induced by crystalline silica particles. We report here that, in NMRI mice, the lung response to silica particles is accompanied by a mild and non progressive pulmonary inflammation which is dispensable for the development of lung fibrosis. We found that glucocorticoid (dexamethasone) dramatically reduced lung injury, cellular inflammation and pro-inflammatory cytokine expression (TNF-?, IL-1? and KC) but had no significant effect on silica-induced lung fibrosis and expression of the fibrogenic and suppressive cytokines TGF-? and IL-10 in mice. Other anti-inflammatory molecules such as the COX inhibitor piroxicam or the phosphodiesterase 5 inhibitor sildenafil also reduced lung inflammation without modifying collagen, TGF-? or IL-10 lung content. Our findings indicate that the development of lung fibrosis in silica-treated NMRI mice is not driven by inflammatory lung responses and suggest that suppressive cytokines may represent critical fibrotic factors and potential therapeutic targets in silicosis. PMID:21414392

Rabolli, Virginie; Lo Re, Sandra; Uwambayinema, Francine; Yakoub, Yousof; Lison, Dominique; Huaux, François

2011-03-23

283

Targeted Cytoplasmic Irradiation with Alpha Particles Induces Mutations in Mammalian Cells  

NASA Astrophysics Data System (ADS)

Ever since x-rays were shown to induce mutation in Drosophila more than 70 years ago, prevailing dogma considered the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, as being due mostly to direct damage to the nucleus. Although there was indication that alpha particle traversal through cellular cytoplasm was innocuous, the full impact remained unknown. The availability of the microbeam at the Radiological Research Accelerator Facility of Columbia University made it possible to target and irradiate the cytoplasm of individual cells in a highly localized spatial region. By using dual fluorochrome dyes (Hoechst and Nile Red) to locate nucleus and cellular cytoplasm, respectively, thereby avoiding inadvertent traversal of nuclei, we show here that cytoplasmic irradiation is mutagenic at the CD59 (S1) locus of human-hamster hybrid (AL) cells, while inflicting minimal cytotoxicity. The principal class of mutations induced are similar to those of spontaneous origin and are entirely different from those of nuclear irradiation. Furthermore, experiments with radical scavenger and inhibitor of intracellular glutathione indicated that the mutagenicity of cytoplasmic irradiation depends on generation of reactive oxygen species. These findings suggest that cytoplasm is an important target for genotoxic effects of ionizing radiation, particularly radon, the second leading cause of lung cancer in the United States. In addition, cytoplasmic traversal by alpha particles may be more dangerous than nuclear traversal, because the mutagenicity is accomplished by little or no killing of the target cells.

Wu, Li-Jun; Randers-Pehrson, Gerhard; Xu, An; Waldren, Charles A.; Geard, Charles R.; Yu, Zengliang; Hei, Tom K.

1999-04-01

284

Targeted cytoplasmic irradiation with alpha particles induces mutations in mammalian cells  

PubMed Central

Ever since x-rays were shown to induce mutation in Drosophila more than 70 years ago, prevailing dogma considered the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, as being due mostly to direct damage to the nucleus. Although there was indication that alpha particle traversal through cellular cytoplasm was innocuous, the full impact remained unknown. The availability of the microbeam at the Radiological Research Accelerator Facility of Columbia University made it possible to target and irradiate the cytoplasm of individual cells in a highly localized spatial region. By using dual fluorochrome dyes (Hoechst and Nile Red) to locate nucleus and cellular cytoplasm, respectively, thereby avoiding inadvertent traversal of nuclei, we show here that cytoplasmic irradiation is mutagenic at the CD59 (S1) locus of human–hamster hybrid (AL) cells, while inflicting minimal cytotoxicity. The principal class of mutations induced are similar to those of spontaneous origin and are entirely different from those of nuclear irradiation. Furthermore, experiments with radical scavenger and inhibitor of intracellular glutathione indicated that the mutagenicity of cytoplasmic irradiation depends on generation of reactive oxygen species. These findings suggest that cytoplasm is an important target for genotoxic effects of ionizing radiation, particularly radon, the second leading cause of lung cancer in the United States. In addition, cytoplasmic traversal by alpha particles may be more dangerous than nuclear traversal, because the mutagenicity is accomplished by little or no killing of the target cells.

Wu, Li-Jun; Randers-Pehrson, Gerhard; Xu, An; Waldren, Charles A.; Geard, Charles R.; Yu, ZengLiang; Hei, Tom K.

1999-01-01

285

Interferon induction by viruses. VIII. Vesicular stomatitis virus: (+-)DI-011 particles induce interferon in the absence of standard virions  

SciTech Connect

Evidence was presented that VSV (+-)DI-011 particles, which contain a genome of covalently linked totally self-complementary RNA, were excellent inducers of interferon (IFN) - by virtue of the dsRNA presumed to form within an infected cell, and that one molecule of that dsRNA per cell sufficed to induce a quantum yield of IFN. While the IFN-inducing capacity of (+-)DI-011 particle preparations has been confirmed, some researchers contend that DIP by themselves cannot induce IFN and that induction requires the presence of coinfecting (contaminating) standard VSV PFP. Consequently, we reexamined this question and now report that under five different conditions where the function of contaminating standard virus is reduced markedly, or eliminated, there was no diminution of the interferon-inducing particle (IFP) activity in preparations of (+-)DI-011 particles. Thus, inactivation of contaminating PFP by uv radiation or heat, the elimination (during induction) of cycling infection through the use of anti-serum (in the case of mouse L cells), and the reduction of PFP by four successive velocity sedimentation-gradient purifications had no adverse affect on the IFN-inducing capacity of DI-011 in either ''aged'' primary chick embryo cells or in mouse L(Y) cells. Furthermore, dilutions of DI-011 stocks which precluded the presence of even a single PFP still induced IFN in ''aged'' chick embryo cells. In concert these data demonstrate convincingly that IFN induction by DI-011 particles does not require coinfection with standard virus. It follows that DI-011 particles are intrinsically capable of inducing IFN.

Sekellick, M.J.; Marcus, P.I.

1982-02-01

286

Quinones and Aromatic Chemical Compounds in Particulate Matter Induce Mitochondrial Dysfunction: Implications for Ultrafine Particle Toxicity  

PubMed Central

Particulate pollutants cause adverse health effects through the generation of oxidative stress. A key question is whether these effects are mediated by the particles or their chemical compounds. In this article we show that aliphatic, aromatic, and polar organic compounds, fractionated from diesel exhaust particles (DEPs), exert differential toxic effects in RAW 264.7 cells. Cellular analyses showed that the quinone-enriched polar fraction was more potent than the polycyclic aromatic hydrocarbon (PAH)–enriched aromatic fraction in O2•? generation, decrease of membrane potential (??m), loss of mitochondrial membrane mass, and induction of apoptosis. A major effect of the polar fraction was to promote cyclosporin A (CsA)–sensitive permeability transition pore (PTP) opening in isolated liver mitochondria. This opening effect is dependent on a direct effect on the PTP at low doses as well as on an effect on ??m at high doses in calcium (Ca2+)-loaded mitochondria. The direct PTP effect was mimicked by redox-cycling DEP quinones. Although the aliphatic fraction failed to perturb mitochondrial function, the aromatic fraction increased the Ca2+ retention capacity at low doses and induced mitochondrial swelling and a decrease in ??m at high doses. This swelling effect was mostly CsA insensitive and could be reproduced by a mixture of PAHs present in DEPs. These chemical effects on isolated mitochondria could be reproduced by intact DEPs as well as ambient ultrafine particles (UFPs). In contrast, commercial polystyrene nanoparticles failed to exert mitochondrial effects. These results suggest that DEP and UFP effects on the PTP and ??m are mediated by adsorbed chemicals rather than the particles themselves.

Xia, Tian; Korge, Paavo; Weiss, James N.; Li, Ning; Venkatesen, M. Indira; Sioutas, Constantinos; Nel, Andre

2004-01-01

287

A new mechanism for DNA alterations induced by alpha particles such as those emitted by radon and radon progeny.  

PubMed Central

The mechanism(s) by which alpha (alpha) particles like those emitted from inhaled radon and radon progeny cause their carcinogenic effects in the lung remains unclear. Although direct nuclear traversals by alpha-particles may be involved in mediating these outcomes, increasing evidence indicates that a particles can cause alterations in DNA in the absence of direct hits to cell nuclei. Using the occurrence of excessive sister chromatid exchanges (SCE) as an index of DNA damage in human lung fibroblasts, we investigated the hypothesis that alpha-particles may induce DNA damage through the generation of extracellular factors. We have found that a relatively low dose of alpha-particles can result in the generation of extracellular factors, which, upon transfer to unexposed normal human cells, can cause excessive SCE to an extent equivalent to that observed when the cells are directly irradiated with the same irradiation dose. A short-lived, SCE-inducing factor(s) is generated in alpha-irradiated culture medium containing serum in the absence of cells. A more persistent SCE-inducing factor(s), which can survive freeze-thaw and is heat labile is produced by fibroblasts after exposure to the alpha-particles. These results indicate that the initiating target for alpha-particle-induced genetic changes can be larger than a cell's nucleus or even a whole cell. How transmissible factors like those observed here in vitro may extend to the in vivo condition in the context of a-particle-induced carcinogenesis in the respiratory tract remains to be determined.

Lehnert, B E; Goodwin, E H

1997-01-01

288

Interaction of the human cytomegalovirus particle with the host cell induces hypoxia-inducible factor 1 alpha  

SciTech Connect

The cellular protein hypoxia-inducible factor 1 alpha (HIF-1{alpha}) was induced after infection of human fibroblasts with human cytomegalovirus (HCMV). HCMV irradiated with ultraviolet light (uv-HCMV) also elicited the effect, demonstrating that the response was provoked by interaction of the infecting virion with the cell and that viral gene expression was not required. Although induction of HIF-1{alpha} was initiated by an early event, accumulation of the protein was not detected until 9 hours post infection, with levels increasing thereafter. Infection with uv-HCMV resulted in increased abundance of HIF-1{alpha}-specific RNA, indicating stimulation of transcription. In addition, greater phosphorylation of the protein kinase Akt was observed, and the activity of this enzyme was required for induction of HIF-1{alpha} to occur. HIF-1{alpha} controls the expression of many cellular gene products; therefore the findings reveal new ways in which interaction of the HCMV particle with the host cell may cause significant alterations to cellular physiology.

McFarlane, Steven; Nicholl, Mary Jane; Sutherland, Jane S.; Preston, Chris M., E-mail: Christopher.preston@glasgow.ac.u

2011-05-25

289

Induced pluripotent stem cells as tools for disease modelling and drug discovery in Alzheimer's disease.  

PubMed

Alzheimer's disease (AD) is a progressive neurodegenerative brain disorder that leads to a progressive decline in a person's memory and ability to communicate and carry out daily activities. The brain pathology in AD is characterized by extensive neuronal loss, particularly of cholinergic neurons, intracellular neurofibrillary tangles composed of the tau protein (NFTs) and extracellular deposition of plaques composed of ?-amyloid (A?), a cleavage product of the amyloid precursor protein (APP). These two insoluble protein aggregates are accompanied by a chronic inflammatory response and extensive oxidative damage. Whereas dys-regulation of APP expression or processing appears to be important for the familial, early-onset form of AD, controversy exists between the "Baptists" (in favour of A?) and the "Tauists" (in favour of tau) as to which of these two protein dysfunctions occur at the earliest stages or are the most important contributors to the disease process in sporadic AD. However, more and more "non-amyloid" and "non-tau" causes have been proposed, including, glycation, inflammation, oxidative stress and dys-regulation of the cell cycle. However, to get an insight into the ultimate cause of AD, and to prove that any drug target is valuable in AD, disease-relevant models giving insight into the pathogenic processes in AD are urgently needed. In the absence of a good animal model for sporadic AD, we propose in this review that induced pluripotent stem cells, derived from dermal fibroblasts of AD patients, and differentiated into cholinergic neurons, might be a promising novel tool for disease modelling and drug discovery for the sporadic form of AD. PMID:22695755

Ooi, Lezanne; Sidhu, Kuldip; Poljak, Anne; Sutherland, Greg; O'Connor, Michael D; Sachdev, Perminder; Münch, Gerald

2012-06-13

290

Implications of prion-induced diseases for animal-derived pharmaceutical products.  

PubMed

The implications of prion-induced diseases for the use of medications that theoretically could harbor the infectious pathogens are discussed. Prions have been identified as protein particles that lack nucleic acids. There is evidence that prions cause the transmissible neurodegenerative diseases known as transmissible spongiform encephalopathies. Of these diseases, bovine spongiform encephalopathy (BSE) and the human spongiform encephalopathy to which it has been linked, new variant Creutzfeldt-Jakob disease (CJD), have generated the most attention. The first cases of new variant CJD appeared in Britain in the mid-1990s. Ingestion of prion-infected beef remains the only known cause of new variant CJD. No cases of BSE or new variant CJD have been documented in the United States. The time from exposure to the development of clinical sequelae appears to be about 10 years. The median duration of illness is 14 months, and the outcome is invariably death. There is no treatment; currently the only available approach is prevention. There is no reliable method of predicting the number of new cases that might occur because of lack of definitive information on the efficiency of transmission from animals to humans and the number of people currently infected and at risk for infection. The infectivity of medications and plasma fractionation products containing material from cattle with BSE is unknown, but the risk is believed to be very low. No cases of such transmission have been identified. Guidelines to keep the risk of transmission via medications low have been promulgated by FDA, and further research is warranted. There have been no reports of medications or plasma fractionation products being contaminated with the prions that cause new variant CJD. Ongoing vigilance and research are appropriate, however. PMID:11862637

Erstad, Brian L

2002-02-01

291

Emergency Admissions for Cardiovascular and Respiratory Diseases and the Chemical Composition of Fine Particle Air Pollution  

PubMed Central

Background Population-based studies have estimated health risks of short-term exposure to fine particles using mass of PM2.5 (particulate matter ? 2.5 ?m in aerodynamic diameter) as the indicator. Evidence regarding the toxicity of the chemical components of the PM2.5 mixture is limited. Objective In this study we investigated the association between hospital admission for cardiovascular disease (CVD) and respiratory disease and the chemical components of PM2.5 in the United States. Methods We used a national database comprising daily data for 2000–2006 on emergency hospital admissions for cardiovascular and respiratory outcomes, ambient levels of major PM2.5 chemical components [sulfate, nitrate, silicon, elemental carbon (EC), organic carbon matter (OCM), and sodium and ammonium ions], and weather. Using Bayesian hierarchical statistical models, we estimated the associations between daily levels of PM2.5 components and risk of hospital admissions in 119 U.S. urban communities for 12 million Medicare enrollees (? 65 years of age). Results In multiple-pollutant models that adjust for the levels of other pollutants, an interquartile range (IQR) increase in EC was associated with a 0.80% [95% posterior interval (PI), 0.34–1.27%] increase in risk of same-day cardiovascular admissions, and an IQR increase in OCM was associated with a 1.01% (95% PI, 0.04–1.98%) increase in risk of respiratory admissions on the same day. Other components were not associated with cardiovascular or respiratory hospital admissions in multiple-pollutant models. Conclusions Ambient levels of EC and OCM, which are generated primarily from vehicle emissions, diesel, and wood burning, were associated with the largest risks of emergency hospitalization across the major chemical constituents of PM2.5.

Peng, Roger D.; Bell, Michelle L.; Geyh, Alison S.; McDermott, Aidan; Zeger, Scott L.; Samet, Jonathan M.; Dominici, Francesca

2009-01-01

292

The time dependence of the surface-force-induced contact radius between glass particles and polyurethane substrates: Effects of substrate viscoelasticity on particle adhesion  

Microsoft Academic Search

Glass particles having mean diameters of 20 ?m were deposited onto substrates consisting of cross-linked polyurethane having Young’s moduli of 2.5 and 32 MPa. The surface-force-induced contact radii were then determined, as a function of time for periods between 20 and 3600 min, using scanning electron microscopy. No changes in the contact radius with time was found with either substrate.

R. C. Bowen; L. P. DeMejo; D. S. Rimai; W. B. Vreeland

1991-01-01

293

Studying the cytotoxicity and oxidative stress induced by two kinds of bentonite particles on human B lymphoblast cells in vitro  

Microsoft Academic Search

The aim of the present study was to evaluate the cytotoxicity and oxidative stress induced by native and active bentonite particles (BPs) on human B lymphoblast cells using seven assays. Our results showed that the order of cytotoxicity was: active BPs>native BPs>quartz particles (DQ-12)>gypsum, according to the IC50 values in CCK-8 assay and neutral red uptake (NRU) assay. The lactate

Meibian Zhang; Yezhen Lu; Xiaoxue Li; Qing Chen; Longxi Lu; Mingluan Xing; Hua Zou; Jiliang He

2010-01-01

294

Potential fluctuation associated with the energetic-particle-induced geodesic acoustic mode in the Large Helical Device  

NASA Astrophysics Data System (ADS)

Geodesic acoustic modes (GAM) driven by energetic particles are observed in the Large Helical Device (LHD) by a heavy ion beam probe. The GAM localizes near the magnetic axis. It is confirmed that the energetic-particle-induced GAM is accompanied by an electrostatic potential fluctuation and radial electric field fluctuation. The amplitude of the potential fluctuation is several hundred volts, and it is much larger than the potential fluctuation associated with turbulence-induced GAMs observed in the edge region in tokamak plasmas. The energetic-particle-induced GAM modulates the amplitude of the density fluctuation in a high-frequency range. The observed GAM frequency is constant at the predicted GAM frequency in plasmas with reversed magnetic shear. On the other hand, it shifts upwards from the predicted GAM frequency in plasmas with monotonic magnetic shear.

Ido, T.; Shimizu, A.; Nishiura, M.; Nakamura, S.; Kato, S.; Nakano, H.; Yoshimura, Y.; Toi, K.; Ida, K.; Yoshinuma, M.; Satake, S.; Watanabe, F.; Morita, S.; Goto, M.; Itoh, K.; Kubo, S.; Shimozuma, T.; Igami, H.; Takahashi, H.; Yamada, I.; Narihara, K.; LHD Experiment Group

2011-07-01

295

Understanding the mechanisms of sickle cell disease by simulations with a discrete particle model  

NASA Astrophysics Data System (ADS)

Sickle cell disease (SCD) is an inherited blood disorder characterized by rigid, sickle-shaped red blood cells (RBCs). Because of their rigidity and shape, sickle cells can get stuck in smaller blood vessels, causing blockages and depriving oxygen to tissues. This study develops and applies mathematical models to better understand the mechanism of SCD. Two-dimensional models of RBCs and blood vessels have been constructed by representing them as discrete particles interacting with different forces. The nonlinear, elastic property of healthy RBCs could be adequately reproduced using a cosine angle bending force and a worm-like chain spring force. With the ability to deform, RBCs can squeeze through narrow blood vessels. In modeling sickle cells as rigid bodies and applying repelling and friction forces from the blood vessel, this study shows that geometrical factors (dimensions of the sickle cell and blood vessels) as well as rigidity and adhesiveness of the sickle cell all play an important role in determining how, and if, sickle cells become trapped within narrow blood capillaries. With lack of data to validate the model, this study primarily provides a sensitivity analysis of factors influencing sickle cell occlusion and identified critical data to support future modeling.

Hui, Katrina; Lin, Guang; Pan, Wenxiao

2013-01-01

296

Laboratory experiments on the determination of polycyclic aromatic hydrocarbon coverage of submicrometer particles by laser-induced aerosol photoemission  

SciTech Connect

First measurements of laser-induced photoelectric charging of submicrometer particles with different polycyclic aromatic hydrocarbon (PAH) coatings are presented. Pure carbon and NaCl particles were generated, and a monodisperse fraction was selected for subsequent coating with a PAH. The growth of the particles due to PAH adsorption or condensation was controlled with a screen type diffusion battery with a resolution better than 1 nm. These aerosols were irradiated with an excimer-laser-pumped dye laser that was frequency-doubled with a BBO crystal. Once photoelectrons were emitted, the remaining positively charged particles were detected with an aerosol electrometer. Wavelengths between 207.5 and 241 nm were investigated. Pure NaCl particles showed a clearly nonlinear behavior when irradiated with increasing energy density of the laser at a fixed wavelength, while pure carbon particles showed a linear behavior. The spectral dependences of the charging of NaCl and carbon particles are given for different PAH submonolayer coatings. Emission of coated NaCl particles is enhanced for all the PAHs, while in the case of carbon particles different PAHs had a different influence on the emission.

Niessner, R.; Robers, W.; Wilbring, P.

1989-02-15

297

Observations on the resistance in Hb E thalassaemia disease to induced infection with Plasmodium vivax  

PubMed Central

Subjects with sickle cell trait have been known to offer resistance to induced Plasmodium falciparum infection. The resistance to malarial infection in other haemoglobinopathic disorders is not clearly known. Investigations were undertaken to test for resistance to malaria in Hb E thalassaemia disease. Compared to controls, subjects with Hb E thalassaemia disease were found to have significant resistance to induced Plasmodium vivax infection.

Ray, R. N.; Chatterjea, J. B.; Chaudhuri, R. N.

1964-01-01

298

Bubbling behavior of a fluidized bed of fine particles caused by vibration-induced air inflow  

PubMed Central

We demonstrate that a vibration-induced air inflow can cause vigorous bubbling in a bed of fine particles and report the mechanism by which this phenomenon occurs. When convective flow occurs in a powder bed as a result of vibrations, the upper powder layer with a high void ratio moves downward and is compressed. This process forces the air in the powder layer out, which leads to the formation of bubbles that rise and eventually burst at the top surface of the powder bed. A negative pressure is created below the rising bubbles. A narrow opening at the bottom allows the outside air to flow into the powder bed, which produces a vigorously bubbling fluidized bed that does not require the use of an external air supply system.

Matsusaka, Shuji; Kobayakawa, Murino; Mizutani, Megumi; Imran, Mohd; Yasuda, Masatoshi

2013-01-01

299

Elemental analysis of agricultural soil samples by particle induced X-ray emission (PIXE) technique  

NASA Astrophysics Data System (ADS)

In agriculture, elements essential to vital processes are also called nutrients. A suitable and reliable particle induced X-ray emission (PIXE) methodology for content determination of essential nutrients in soil samples was developed and its effectiveness proved. The PIXE method is applied to intermediate thickness samples, whose mass per area unit are smaller than 1?g/cm2. Precision and accuracy of the method was estimated after repeated measurements of a single reference material: CRM PACS-2 (estuarine sediment) with a matrix quite similar to the soil samples measured. This paper reports the results of elemental measurements in soil samples. A discussion of agricultural soil sample preparation for PIXE analysis is also presented.

Cruvinel, Paulo E.; Flocchini, Robert G.; Artaxo, Paulo; Crestana, Silvio; Herrmann, Paulo S. P., Jr.

1999-04-01

300

Determination of primary particle size distributions from time-resolved laser-induced incandescence measurements.  

PubMed

For a polydisperse nanoparticle ensemble the evaluation of time-resolved laser-induced incandescence (LII) measurements yields a weighted average value for the primary nanoparticle size. Although this value is sufficient for narrow size distributions, a comprehensive characterization of a particle-evolution process requires the reconstruction of the size distribution. An easy-to-use online approach is presented to evaluate the LII signal regarding higher moments of the distribution. One advantage of this approach is that the size distribution results in a deceleration of the LII signal decay with time after the laser pulse. Therefore LII signal-decay curves are evaluated in two different time intervals after the laser pulse, providing information about the desired distribution parameters that has been tested successfully with experimental curves taken in different soot-formation processes. PMID:15218614

Dankers, Stefan; Leipertz, Alfred

2004-06-20

301

Shear-induced reaction-limited aggregation kinetics of Brownian particles at arbitrary concentrations  

NASA Astrophysics Data System (ADS)

The aggregation of interacting Brownian particles in sheared concentrated suspensions is an important issue in colloid and soft matter science per se. Also, it serves as a model to understand biochemical reactions occurring in vivo where both crowding and shear play an important role. We present an effective medium approach within the Smoluchowski equation with shear which allows one to calculate the encounter kinetics through a potential barrier under shear at arbitrary colloid concentrations. Experiments on a model colloidal system in simple shear flow support the validity of the model in the concentration range considered. By generalizing Kramers' rate theory to the presence of shear and collective hydrodynamics, our model explains the significant increase in the shear-induced reaction-limited aggregation kinetics upon increasing the colloid concentration.

Zaccone, Alessio; Gentili, Daniele; Wu, Hua; Morbidelli, Massimo

2010-04-01

302

Effect of the recoil pressure induced by evaporation on motion of powder particles in the light field during laser cladding  

NASA Astrophysics Data System (ADS)

A model is proposed, which takes into account acceleration of powder particles by a force induced by recoil of material vapors from the irradiated region of the particle surface. Results of a numerical analysis of heat and mass transfer in the case of motion of individual stainless steel powder particles in a gas flow and in a light field of laser radiation under conditions of laser cladding are presented. Acceleration of particles is found to depend on their diameter, carrier gas velocity, powder material properties, laser radiation power, and degree of attenuation of the power density in the laser beam in the direction of its action on the substrate. The calculated results are compared with experimental data on light-propulsion acceleration of individual particles (of aluminum, aluminum oxide, and graphite) under the action of pulsed laser radiation.

Kovaleva, I. O.; Kovalev, O. B.

2012-01-01

303

Marek's disease virus induced transient paralysis--a closer look  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s Disease (MD) is a lymphoproliferative disease of domestic chickens caused by a highly cell-associated alpha herpesvirus, Marek’s disease virus (MDV). Clinical signs of MD include depression, crippling, weight loss, and transient paralysis (TP). TP is a disease of the central nervous system...

304

Bystander-induced apoptosis and premature differentiation in primary urothelial explants after charged particle microbeam irradiation.  

PubMed

The ureter primary explant technique was developed to study bystander effects under in vivo like conditions where stem and differentiated cells are present. Irradiation was performed with a 3He2+ charged particle microbeam available at the Gray Cancer Institute, with high (approximately 2 microns) precision. Tissue sections from porcine ureters were pre-irradiated with the microbeam at a single location with 10 3He2+ particles (5 MeV; LET 70 keV.micron-1). After irradiation, the tissue section was incubated for 7 days, thus allowing the explant outgrowth to form. Total cellular damage (total fraction of micronucleated and apoptotic cells) was measured according to morphological criteria. Apoptosis was also assessed using a 3'-OH DNA end-labelling technique. Premature differentiation was estimated using antibodies to uroplakin III, a specific marker of terminal urothelial differentiation. Results of our experiments demonstrated a significant bystander-induced differentiation and a less significant increase in apoptotic and micronucleated cells. A hypothesis based on the protective nature of the bystander effect is proposed. PMID:12194297

Belyakov, O V; Folkard, M; Mothersill, C; Prise, K M; Michael, B D

2002-01-01

305

Mechanism of vibration-induced repulsion force on a particle in a viscous fluid cell.  

PubMed

Space platforms such as the Space Shuttle and International Space Station have been considered an ideal environment for production of protein and semiconductor crystals of superior quality due to the negligible gravity-induced convection. Although it was believed that under microgravity environment diffusive mass transport would dominate the growth of the crystals, some related experiments have not shown satisfactory results possibly due to the movement of the growing crystals in fluid cells caused by small vibrations present in the space platforms called g-jitter. In ground-based experiments, there have been clear observations of attraction and repulsion of a solid particle with respect to a nearby wall of the fluid cell due to small vibrations. The present work is a numerical investigation on the physical mechanisms responsible for the repulsion force, which has been predicted to increase with the cell vibration frequency and amplitude, as well as the fluid viscosity. Moreover, the simulations have revealed that the repulsion force occurs mostly due to the increased pressure in the narrow gap between the particle and the nearest wall. PMID:24032936

Saadatmand, Mehrrad; Kawaji, Masahiro

2013-08-19

306

Modeling particle-induced electron emission in a simplified plasma Test Cell  

NASA Astrophysics Data System (ADS)

Particle-induced electron emission (PIE) is modeled in a simplified, well-characterized plasma Test Cell operated at UCLA. In order for PIE to be a useful model in this environment, its governing equations are first reduced to lower-order models which can be implemented in a direct simulation Monte Carlo and Particle-in-Cell framework. These reduced-order models are described in full and presented as semi-empirical models. The models are implemented to analyze the interaction of low- and high-energy (~1-2 keV) xenon ions and atoms with the stainless steel electrodes of the Test Cell in order to gain insight into the emission and transport of secondary electrons. Furthermore, there is a lack of data for xenon-stainless steel atom- and ion-surface interactions for similar environments. Using experimental data as a reference, both total yields and emitted electron energy distribution functions can be deduced by observing sensitivities of current collection results to these numerical models and their parameters.

Giuliano, Paul N.; Boyd, Iain D.

2013-03-01

307

Mechanism of vibration-induced repulsion force on a particle in a viscous fluid cell  

NASA Astrophysics Data System (ADS)

Space platforms such as the Space Shuttle and International Space Station have been considered an ideal environment for production of protein and semiconductor crystals of superior quality due to the negligible gravity-induced convection. Although it was believed that under microgravity environment diffusive mass transport would dominate the growth of the crystals, some related experiments have not shown satisfactory results possibly due to the movement of the growing crystals in fluid cells caused by small vibrations present in the space platforms called g-jitter. In ground-based experiments, there have been clear observations of attraction and repulsion of a solid particle with respect to a nearby wall of the fluid cell due to small vibrations. The present work is a numerical investigation on the physical mechanisms responsible for the repulsion force, which has been predicted to increase with the cell vibration frequency and amplitude, as well as the fluid viscosity. Moreover, the simulations have revealed that the repulsion force occurs mostly due to the increased pressure in the narrow gap between the particle and the nearest wall.

Saadatmand, Mehrrad; Kawaji, Masahiro

2013-08-01

308

MATERNALLY INDUCED TRANSPLANTATION IMMUNITY, TOLERANCE, AND RUNT DISEASE IN RATS  

PubMed Central

A previous report that the offspring of outbred Sprague-Dawley rats, born of mothers presensitized or tolerant with respect to tissue antigens of the Lewis strain, and reinoculated with Lewis cells during their pregnancy, reject test grafts of Lewis skin in an accelerated manner has been confirmed. This "maternally induced" alteration in reactivity of the progeny has been found to be long lasting, immunologically specific, and probably not due to transfer of humoral antibody. It has been established that the reexposure of the mothers to donor cellular antigen during pregnancy augmented the influence of the prior states of tolerance or sensitivity. To obviate the complications inherent in working with the outbred Sprague-Dawley rats, the key experiments summarized above were repeated with isogenic Fischer rats as parents and Lewis rats as the tissue donors as before. With this combination it was found that a state of prior sensitization or tolerance in the mothers resulted in the apparent induction of tolerance in some of their progeny. Reinoculation of either the tolerant or sensitized mothers during pregnancy slightly increased the incidence and degree of impairment of their offsprings' capacity to reject Lewis skin grafts. A single intraperitoneal injection of 100 x 106 million Lewis lymphoid cells into normal Fischer rats in the 14th–16th day of pregnancy also weakened the reactivity of their progeny to Lewis test grafts. Further to test the premise that this weakened reactivity might be due to maternal induction of tolerance, by antenatal transmission of alien cells, the lymphohematopoietic tissue system of adult Fischer females was replaced by that from Lewis donors with the aid of cyclophosphamide. It was anticipated that when these animals were mated with Fischer males, sufficient Lewis leukocytes might cross the placentas to induce high degrees of tolerance. Although normal sized healthy litters were born, about 50% of the infants succumbed to graft-versus-host (GVH) or runt disease within 40 days, many of them giving evidence of being tolerant of Lewis grafts. The mothers, too, developed chronic GVH disease. The offspring of Fischer females made chimeric with cells from (Fischer x Lewis)F1 hybrid donors, as well as their mothers, remained healthy. Intraperitoneal injection of normal Fischer females, in the 15th–17th day of pregnancy, with 100 million lymphoid cells from specifically sensitized Lewis rats, also caused fatal runt disease to develop in about 50% of their offspring, but left the mothers unscathed. Taken together, these various findings indicate that in some genetic contexts at least the extent of the natural surreptitious transplacental cellular traffic can be considerably augmented experimentally, though how this comes about and why lymphocytic cells that are foreign to the mother can apparently gain access to fetuses more readily than her own cells remain to be determined.

Beer, Alan E.; Billingham, R. E.; Yang, S. L.

1972-01-01

309

Modeling three-dimensional constituent particle microstructure and particle-induced pitting corrosion in rolled aluminum alloys  

Microsoft Academic Search

In the last two decades there has been a surge in research surrounding the corrosion and fatigue properties of high strength aluminum alloys aimed at extending the service life of commercial and military aircraft. It is recognized that corrosion damage in aluminum alloys is the direct result of local galvanic coupling between constituent particles and the metal matrix. As the

Matthew Joseph Cullin

2009-01-01

310

Anacardic Acids from Cashew Nuts Ameliorate Lung Damage Induced by Exposure to Diesel Exhaust Particles in Mice  

PubMed Central

Anacardic acids from cashew nut shell liquid, a Brazilian natural substance, have antimicrobial and antioxidant activities and modulate immune responses and angiogenesis. As inflammatory lung diseases have been correlated to environmental pollutants exposure and no reports addressing the effects of dietary supplementation with anacardic acids on lung inflammation in vivo have been evidenced, we investigated the effects of supplementation with anacardic acids in a model of diesel exhaust particle- (DEP-) induced lung inflammation. BALB/c mice received an intranasal instillation of 50??g of DEP for 20 days. Ten days prior to DEP instillation, animals were pretreated orally with 50, 150, or 250?mg/kg of anacardic acids or vehicle (100??L of cashew nut oil) for 30 days. The biomarkers of inflammatory and antioxidant responses in the alveolar parenchyma, bronchoalveolar lavage fluid (BALF), and pulmonary vessels were investigated. All doses of anacardic acids ameliorated antioxidant enzyme activities and decreased vascular adhesion molecule in vessels. Animals that received 50?mg/kg of anacardic acids showed decreased levels of neutrophils and tumor necrosis factor in the lungs and BALF, respectively. In summary, we demonstrated that AAs supplementation has a potential protective role on oxidative and inflammatory mechanisms in the lungs.

Carvalho, Ana Laura Nicoletti; Annoni, Raquel; Torres, Larissa Helena Lobo; Durao, Ana Carolina Cardoso Santos; Shimada, Ana Lucia Borges; Almeida, Francine Maria; Hebeda, Cristina Bichels; Lopes, Fernanda Degobbi Tenorio Quirino Santos; Dolhnikoff, Marisa; Martins, Milton Arruda; Silva, Luiz Fernando Ferraz; Farsky, Sandra Helena Poliselli; Saldiva, Paulo Hilario Nascimento; Ulrich, Cornelia M.; Owen, Robert W.; Marcourakis, Tania; Trevisan, Maria Teresa Salles; Mauad, Thais

2013-01-01

311

The use of induced sputum in the assessment of pulmonary involvement in Crohn's disease  

Microsoft Academic Search

OBJECTIVE:Our aim was to evaluate lung involvement in Crohn's disease (CRD) patients by induced sputum (IS). Extraintestinal manifestations are frequent in CRD, but lung involvement is rare. Induced sputum is a reliable noninvasive method of investigating the pathogenesis, pathophysiology, and treatment of lung disease.METHODS:Twenty-four CRD patients and nine control subjects (all nonsmokers) without respiratory symptoms were tested. Sputum was induced

Zvi Fireman; Aya Osipov; Shmuel Kivity; Yael Kopelman; Amos Sternberg; Edna Lazarov; Elizabeth Fireman

2000-01-01

312

The Role of Induced Sputum in Amiodarone-Associated Interstitial Lung Diseases  

Microsoft Academic Search

Amiodarone, a highly effective medication for suppressing cardiac rhythm disturbances, may cause pulmonary injury, such as chronic interstitial lung diseases, in 5–15% of the patients who take it. We applied induced sputum (IS), a non-invasive technique, for diagnosing amiodarone-induced pulmonary toxicity. Four patients with interstitial lung disease who were treated by amiodarone for ischemic heart diseases were evaluated by a

Elizabeth Fireman; Ian Topilsky; Sami Viskin; Israel E. Priel

2007-01-01

313

A decoy oligonucleotide to NF-?B delivered through inhalable particles prevents LPS-induced rat airway inflammation.  

PubMed

The inflammatory process plays a crucial role in the onset and progression of several lung pathologies, including cystic fibrosis (CF), and the involvement of NF-?B is widely recognized. The specific inhibition of NF-?B by decoy oligonucleotides delivered within the lung may be beneficial, although rationally designed systems are needed to optimize their pharmacological response. Prompted by this need, we have developed and tested in vivo an inhalable dry powder for the prolonged delivery of a decoy oligodeoxynucleotide to NF-?B (dec-ODN), consisting of large porous particles (LPPs) based on poly(lactic-co-glycolic) acid. First, LPPs containing dec-ODN (dec-ODN LPPs) were engineered to meet the aerodynamic criteria crucial for pulmonary delivery, to gain an effective loading of dec-ODN, to sustain its release, and to preserve its structural integrity in lung lining fluids. We then investigated the effects of dec-ODN LPPs in a rat model of lung inflammation induced by the intratracheal aerosolization of LPS from Pseudomonas aeruginosa. The results show that a single intratracheal insufflation of dec-ODN LPPs reduced the bronchoalveolar neutrophil infiltration induced by LPS for up to 72 hours, whereas naked dec-ODN was able to inhibit it only at 6 hours. The persistent inhibition of neutrophil infiltrate was associated with reduced NF-?B/DNA binding activity, as well as reduced IL-6, IL-8, and mucin-2 mRNA expression in lung homogenates. We consider it noteworthy that the developed LPPs, preventing the accumulation of neutrophils and NF-?B-related gene expression, may provide a new therapeutic option for the local treatment of inflammation associated with lung disease. PMID:23590300

De Stefano, Daniela; Coletta, Ciro; Bianca, Roberta d'Emmanuele di Villa; Falcone, Lucia; d'Angelo, Ivana; Ungaro, Francesca; Quaglia, Fabiana; Carnuccio, Rosa; Sorrentino, Raffaella

2013-08-01

314

Neutrino-Induced Reactions for Nucleosynthesis by the Quasi-particle RPA  

SciTech Connect

We calculated neutrino-induced reactions in the energy range below the quasi-elastic region for nuclei of astrophysical importance. Neutrino-induced reactions have been found to be important for the nucleosynthesis in core collapsing supernovae explosions because expected neutrino flux is sufficiently high enough to excite many relevant nuclei in spite of small cross sections of the weak interaction. Our calculations are carried out with the Quasi-particle Random Phase Approximation (QRPA), which successfully described the nuclear beta decays of relevant nuclei by taking neutron-proton pairing as well as neutron-neutron and proton-proton pairing correlations into account. To describe neutrino-nucleus reactions, general multipole transitions by the weak interaction with finite momentum transfers are considered for neutral and charged current reactions. Both reactions are described in a theoretical framework. Our results are shown to well reproduce the sparse experimental data and extended further for neutrino reactions on various nuclear targets. Parts of the results are reported in this talk.

Cheoun, Myung-Ki [Department of Physics, Soongsil University, Seoul, 156-743 (Korea, Republic of); Ha, Eunja; Kajino, T. [National Astronomical Observatory, Mitaka Tokyo 181-8589 (Japan); Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033 (Japan)

2010-08-12

315

Wear particles promote endotoxin tolerance in macrophages by inducing interleukin-1 receptor-associated kinase-M expression.  

PubMed

Toll-like receptors (TLRs) recognizing pathogen-associated molecular patterns (PAMP) play a role in local immunity and participate in implant-associated loosening. TLRs-mediated signaling is regulated by interleukin-1 receptor-associated kinase-M (IRAK-M). Our previous studies have proved that IRAK-M is induced by wear particles in macrophages from periprosthetic tissues. In this study, the IRAK-M-related mechanisms were further explored by lipopolysaccharide (LPS) and/or titanium (Ti) particles stimulations and small interfering RNAs (siRNAs). The protein level of IRAK-M was studied using western blotting and tumor necrosis factor-? (TNF-?), and interleukin-1? (IL-1?) levels were measured using ELISA. Results showed that in RAW264.7 cells stimulated by LPS after Ti particle pre-exposure, IRAK-M was slightly changed, compared with LPS stimulation. And levels of TNF-? and IL-1? in cultures stimulated by LPS first after Ti particle pre-exposure were lower than in the other two groups which were stimulated by LPS with or without Ti particles (p < 0.001), whereas there were no statistic differences between the later two (p > 0.05). The cytokines were lowest in Ti particles alone stimulation. After siRNAs silenced, IRAK-M-deficient cells exhibited increased expression of the cytokines in LPS stimulation after Ti particle pre-exposure and when stimulated with Ti particles alone. Our findings suggest that debris-induced IRAK-M decreases foreign body reactions, but at the same time, the over-expression of IRAK-M may also be detrimental on local intrusion of PAMPs or bacteria, negatively regulates the LPS-induced and TLRs-mediated inflammation and results in immunosuppression in periprosthetic tissue, which may predispose to implant-associated infections. PMID:22941946

Zhang, Yangchun; Yu, Shiming; Xiao, Jianhong; Hou, Changhe; Li, Ziqing; Zhang, Ziji; Zhai, Qiyi; Lehto, Matti; Konttinen, Yrjö T; Sheng, Puyi

2012-08-31

316

Marek's Disease Virus-Induced Immunosuppression: Array Analysis of Chicken Immune Response Gene Expression Profiling  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease (MD) is a lymphoproliferative disease of chickens induced by a highly cell-associated oncogenic alpha-herpesvirus, Marek’s disease virus (MDV). MDV replicates in chicken lymphocytes and establishes a latency infection within CD4+ T cells. Host-virus interaction, immune responses to...

317

Immune responses induced by lower airway mucosal immunisation with a human papillomavirus type 16 virus-like particle vaccine  

Microsoft Academic Search

Cervical cancer results from cervical infection by human papillomaviruses (HPV), especially HPV16. Previous studies have shown that intramuscular vaccination of women with an HPV16 virus-like particle (VLP) vaccine induced a strong IgG response and protected against genital HPV16 infection. However, an alternative route of administration that avoids parenteral injection while inducing mucosal immunity might facilitate vaccine implementation in some settings,

Denise Nardelli-Haefliger; Floriana Lurati; Daniel Wirthner; François Spertini; John T. Schiller; Douglas R. Lowy; Françoise Ponci; Pierre De Grandi

2005-01-01

318

Evaluation of hydrophobic and hydrophilic kaolin particle films for peach crop, arthropod and disease management.  

PubMed

Hydrophobic and/or hydrophilic kaolin particle film treatments to peach (Prunus persica (L) Batsch) trees were evaluated for crop and pest management capabilities in six studies from 1997 to 2000. Unsprayed control and standard treatments, the latter consisting of a commercial pesticide program, were included for comparison. Treatments in initial studies were applied via handgun, which resulted in a uniform and heavy deposit of kaolin after the first application. In contrast, treatments in subsequent studies used airblast equipment, which provided a uniform but less dense coverage, even after multiple applications. Results showed that both formulations of kaolin provided control of oriental fruit moth (Grapholita molesta (Busck)), plum curculio (Conotrachelus nenuphar (Herbst)) and Japanese beetle (Popillia japonica Newman) that was comparable with or better than the standard pesticide program. Effective management of late season catfacing insects (tarnished plant bugs Lygus lineolaris (Palisot de Beauvois) and stinkbugs Acrosternum hilare (Say), Euschistus servus (Say), and E tristigmus (Say)) and leafrollers (undetermined species) was also observed, although kaolin applications significantly increased phytophagous mite (Panonychus ulmi (Koch)) levels. In contrast to arthropod management, kaolin failed to control either peach scab (Cladosporium carpophilum (Von Thumen)) or rusty spot (Podosphaera leucotricha (Ell and Ev) ES Salmon) in any of the 4 years of the study. However, hydrophobic kaolin provided effective brown rot (Monilinia fructicola (G Winter) Honey) control when applied via handgun, and partial control when applied via airblast; hydrophilic kaolin failed to provide any control. These results suggest that hydrophobicity and deposit density may be important factors for effective disease management. The application of kaolin significantly delayed fruit maturation, increased fruit size and increased soluble solids relative to the standard. This effect, attributed to a reduction in plant stress, also resulted in increased fruit number and yield on young trees, indicating that an accentuated beneficial response from kaolin applications may be possible. PMID:15593071

Lalancette, Norman; Belding, Robert D; Shearer, Peter W; Frecon, Jerome L; Tietjen, William H

2005-01-01

319

Propagation distance of the alpha-particle-induced bystander effect: the role of nuclear traversal and gap junction communication.  

PubMed

When cell populations are exposed to low-dose alpha-particle radiation, a significant fraction of the cells will not be traversed by a radiation track. However, stressful effects occur in both irradiated and bystander cells in the population. Characterizing these effects, and investigating their underlying mechanism(s), is critical to understanding human health risks associated with exposure to alpha particles. To this end, confluent normal human fibroblast cultures were grown on polyethylene terephthalate foil grafted to an ultrathin solid-state nuclear track detector and exposed under non-perturbing conditions to low-fluence alpha particles from a broadbeam irradiator. Irradiated and affected bystander cells were localized with micrometer precision. The stress-responsive protein p21(Waf1) (also known as CDKN1A) was induced in bystander cells within a 100-microm radius from an irradiated cell. The mean propagation distance ranged from 20 to 40 microm around the intranuclear alpha-particle impact point, which corresponds to a set of approximately 30 cells. Nuclear traversal, induced DNA damage, and gap junction communication were critical contributors to propagation of this stressful effect. The strategy described here may be ideal to investigate the size of radiation-affected target and the relative contribution of different cellular organelles to bystander effects induced by energetic particles, which is relevant to radioprotection and cancer radiotherapy. PMID:19580486

Gaillard, Sylvain; Pusset, David; de Toledo, Sonia M; Fromm, Michel; Azzam, Edouard I

2009-05-01

320

Propagation Distance of the ?-Particle-Induced Bystander Effect: The Role of Nuclear Traversal and Gap Junction Communication  

PubMed Central

When cell populations are exposed to low-dose ?-particle radiation, a significant fraction of the cells will not be traversed by a radiation track. However, stressful effects occur in both irradiated and bystander cells in the population. Characterizing these effects, and investigating their underlying mechanism(s), is critical to understanding human health risks associated with exposure to ? particles. To this end, confluent normal human fibroblast cultures were grown on polyethylene terephthalate foil grafted to an ultrathin solid-state nuclear track detector and exposed under non-perturbing conditions to low-fluence ? particles from a broadbeam irradiator. Irradiated and affected bystander cells were localized with micrometer precision. The stress-responsive protein p21Waf1 (also known as CDKN1A) was induced in bystander cells within a 100-µm radius from an irradiated cell. The mean propagation distance ranged from 20 to 40 µm around the intranuclear ?-particle impact point, which corresponds to a set of ?30 cells. Nuclear traversal, induced DNA damage, and gap junction communication were critical contributors to propagation of this stressful effect The strategy described here may be ideal to investigate the size of radiation-affected target and the relative contribution of different cellular organelles to bystander effects induced by energetic particles, which is relevant to radioprotection and cancer radiotherapy.

Gaillard, Sylvain; Pusset, David; de Toledo, Sonia M.; Fromm, Michel; Azzam, Edouard I.

2009-01-01

321

Reaction Mechanisms in HELIUM3 Induced Projectile Breakup: a Study of Breakup-Related Processes Induced by HELIUM3 Particles at E(HELIUM3) = 52 Mev  

Microsoft Academic Search

Inclusive proton and deuteron spectra from He induced reactions on ('12)C, ('28)Si and ('58)Ni have been studied. Each spectrum contains a continuum part that may be separated into a broad bump, centered around beam velocity energies at forward angles, and an exponential tail. The properties of each of these components have been investigated as function of outgoing particle, detection angle

Emile Hubertus Leonardus Aarts

1984-01-01

322

Amphetamine-Induced Taste Aversion Learning in Young and Old F-344 Rats Following Exposure to 56Fe Particles  

Technology Transfer Automated Retrieval System (TEKTRAN)

Exposure to 56Fe particles produces changes in dopaminergic function and in dopamine dependent behaviors, including amphetamine-induced conditioned taste aversion (CTA) learning. Because many of these changes are characteristic of the changes that accompany the aging process, the present study was ...

323

Shear-induced particle migration in Couette and parallel-plate viscometers: NMR imaging and stress measurements  

Microsoft Academic Search

Couette and parallel plate viscometers are two commonly used flow geometries to characterize shear viscosity of concentrated suspensions. In Couette flow, it is well documented that prolonged shearing causes a decrease in the apparent viscosity of concentrated suspensions due to shear-induced particle migration from the annulus region to the stagnant region under the bob. In this study, the technique of

Andrea W. Chow; Steven W. Sinton; Joseph H. Iwamiya; Thomas S. Stephens

1994-01-01

324

Virus-Like Particles in 3-Methylcholathrene-Induced Primary and Transplanted Sarcomas of Germ-Free Rodents.  

National Technical Information Service (NTIS)

Primary and serially transplanted 3-methylcholanthrene-induced sarcomas of germ-free mice and rats and the thymuses of tumor-bearing and tumor-free experimental animals were examined by electron microscopy for virus particles. The results can be summarize...

M. Kajima M. Pollard

1967-01-01

325

Glutathione-S-transferase M1 regulation of diesel exhaust particle-induced pro-inflammatory mediator expression in normal human bronchial epithelial cells  

PubMed Central

Background Diesel exhaust particles (DEP) contribute substantially to ambient particulate matter (PM) air pollution in urban areas. Inhalation of PM has been associated with increased incidence of lung disease in susceptible populations. We have demonstrated that the glutathione S-transferase M1 (GSTM1) null genotype could aggravate DEP-induced airway inflammation in human subjects. Given the critical role airway epithelial cells play in the pathogenesis of airway inflammation, we established the GSTM1 deficiency condition in primary bronchial epithelial cells from human volunteers with GSTM1 sufficient genotype (GSTM1+) using GSTM1 shRNA to determine whether GSTM1 deficiency could exaggerate DEP-induced expression of interleukin-8 (IL-8) and IL-1? proteins. Furthermore, the mechanisms underlying GSTM1 regulation of DEP-induced IL-8 and IL-1? expression were also investigated. Methods IL-8 and IL-1? protein levels were measured using enzyme-linked immunosorbent assay. GSTM1 deficiency in primary human bronchial epithelial cells was achieved using lentiviral GSTM1 shRNA particles and verified using real-time polymerase chain reaction and immunoblotting. Intracellular reactive oxygen species (ROS) production was evaluated using flow cytometry. Phosphorylation of protein kinases was detected using immunoblotting. Results Exposure of primary human bronchial epithelial cells (GSTM1+) to 25-100??g/ml DEP for 24?h significantly increased IL-8 and IL-1? protein expression. Knockdown of GSTM1 in these cells further elevated DEP-induced IL-8 and IL-1? expression, implying that GSTM1 deficiency aggravated DEP-induced pro-inflammatory response. DEP stimulation induced the phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, the downstream kinase of phosphoinositide 3-kinase (PI3K), in GSTM1+ bronchial epithelial cells. Pharmacological inhibition of ERK kinase and PI3K activity blocked DEP-induced IL-8 and IL-1? expression. DEP-induced ERK and Akt phosphorylation could be increased by GSTM1 knockdown. In addition, pretreatment of HBEC with the antioxidant N-acetyl cysteine significantly inhibited DEP-induced ERK and Akt phosphorylation, and subsequent IL-8 and IL-1? expression. Conclusion GSTM1 regulates DEP-induced IL-8 and IL-1? expression in primary human bronchial epithelial cells by modulation of ROS, ERK and Akt signaling.

2012-01-01

326

Gravitational perturbation of the BTZ black hole induced by test particles and weak cosmic censorship in AdS spacetime  

SciTech Connect

We analyze the gravitational perturbations induced by particles falling into a three dimensional, asymptotically AdS black hole geometry. More specifically, we solve the linearized perturbation equations obtained from the geodesic motion of a ringlike distribution of test particles in the BTZ background. This setup ensures that the U(1) symmetry of the background is preserved. The nonasymptotic flatness of the background raises difficulties in attributing the significance of energy and angular momentum to the conserved quantities of the test particles. This issue is well known but, to the best of our knowledge, has never been addressed in the literature. We confirm that the naive expressions for energy and angular momentum are the correct definitions. Finally, we put an asymptotically AdS version of the weak cosmic censorship to a test: by attempting to overspin the BTZ black hole with test particles it is found that the black hole cannot be spun-up past its extremal limit.

Rocha, Jorge V. [CENTRA, Departamento de Fisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais 1, 1049 Lisboa (Portugal); Cardoso, Vitor [CENTRA, Departamento de Fisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais 1, 1049 Lisboa (Portugal); Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677 (United States)

2011-05-15

327

Exposure to metal welding fume particles and risk for cardiovascular disease in Denmark: a prospective cohort study  

Microsoft Academic Search

ObjectivesTo study welding fume particles in relation to cardiovascular diseases.MethodsIn 1986, 10 059 male metal workers in 75 welding companies were sent a questionnaire about their welding experience and lifestyle (83.3% response rate). Of these, 5866 were available for analysis and had ever welded at baseline. Information on exposure to welding fumes after 1986 was obtained by individual linkage to

Else Ibfelt; Jens Peter Bonde; Johnni Hansen

2010-01-01

328

Properties of virus-like particles associated with banana bunchy top disease in Hawaii, Indonesia and Tonga  

Microsoft Academic Search

Field samples of banana plants affected by bunchy top disease from Hawaii, Indonesia and Tonga, but not unaffected controls,\\u000a gave strong positive reactions when tested by enzyme-linked immunosorbent assay using Australian polyclonal and Australian\\u000a and Taiwanese monoclonal antibodies specific for banana bunchy top virus (BBTV). Isometric virus-like particles, 18-19 nm\\u000a in diameter, were isolated from these field samples. BBTV-Indonesia, BBTV-Hawaii

R. G. Dietzgen; J. E. Thomas

1991-01-01

329

Association of remnant-like particle cholesterol with coronary artery disease in patients with normal total cholesterol levels  

Microsoft Academic Search

Background Limited information is available as to whether there is a difference in the association of lipid and fibrinolytic variables with coronary artery disease according to the presence or absence of elevated serum total cholesterol. We examined the levels of various lipid and fibrinolytic variables including remnant-like particle cholesterol (RLP-C). RLP-C is a recently established simple assay method for the

Hiroshi Masuoka; Shigeru Kamei; Hidetaka Wagayama; Morihiro Ozaki; Atsushi Kawasaki; Tsuyoshi Tanaka; Masami Kitamura; Shigeki Katoh; Uichiro Shintani; Moriharu Misaki; Masahiro Sugawa; Masaaki Ito; Takeshi Nakano

2000-01-01

330

Synthesis of adenosine triphosphate in respiration-inhibited submitochondrial particles induced by microsecond electric pulses  

PubMed Central

Phosphorylation of ADP to ATP was induced in nonrespiring submitochondrial particles (SMP) from rat liver by the application of electric pulses with field strengths of 10-35 kV/cm and a decay time of 60 ?s. In all cases respiration was inhibited completely by using cyanide or rotenone. Newly formed ATP was measured by two independent methods, (i) the luciferase/luciferin bioluminescence assay and (ii) synthesis of [32P]ATP from ADP and 32Pi. Both methods gave consistent and essentially identical results. Above 10 kV/cm the amount of ATP synthesized increased with increasing field strength, and at 30 kV/cm, approximately 40 pmol of ATP was synthesized per mg of SMP protein per pulse. ATP synthesis was shown to be related to the field-induced transmembrane potential, not to Joule heating of the suspension. Synthesis was abolished by the uncouplers carbonyl cyanide p-trifluoromethoxyphenylhydrazone, carbonyl cyanide m-chlorophenylhydrazone, and 2,4-dinitrophenol. The ionophores valinomycin and A23187 reduced the level of synthesis by 75% and 50%, respectively. ATP synthesis was also blocked by inhibitors of the F0F1 ATPase complex, oligomycin, N,N?-dicyclohexyl carbodiimide, venturicidin, and aurovertin. The activities of the adenine nucleotide translocator and adenylate kinase, as well as release of bound nucleotides, could be excluded as sources of the new ATP. The data indicate that the minimal applied field at which ATP synthesis could be detected is approximately 8 kV/cm, corresponding to a maximal induced membrane potential of 60 mV in SMP. The maximal synthesis occurred at around 30 kV/cm, or an induced transmembrane potential of 200 mV. The duration of the applied pulse was also found to be critical, with 8 ?s being the minimal triggering time for the synthesis. The induction of ATP synthesis in nonrespiring SMP by an externally applied electrical field is a direct demonstration of the transformation, by the mitochondrial inner membrane, of electrical energy into the chemical bond energy of ATP.

Teissie, Justin; Knox, Barry E.; Tsong, Tian Yow; Wehrle, Janna

1981-01-01

331

Adenovirus-mediated small interfering RNA targeting tumor necrosis factor-? inhibits titanium particle-induced osteoclastogenesis and bone resorption.  

PubMed

Wear particles are phagocytosed by macrophages, resulting in cellular activation and the release of pro-inflammatory factors, which cause periprosthetic osteolysis and subsequent aseptic loosening, the most common causes of total joint arthroplasty (TJA) failure. During this pathological process, tumor necrosis factor (TNF)-? plays an important role in wear particle-induced osteolysis. Therefore, in this study, we used adenovirus-mediated small interfering RNA (siRNA) targeting TNF-? to suppress the TNF-? release from activated macrophages in response to titanium particles. Our results showed that recombinant adenovirus (Ad-TNF-?-siRNA) suppressed the TNF-? release from activated macrophages in response to titanium particles, and reduced titanium particle-induced osteoclastogenesis and bone resorption in the presence of receptor activator of nuclear factor-?B ligand (RANKL). In addition, the conditioned medium of macrophages challenged with titanium particles (Ti CM) stimulated osteoprogenitor RANKL expression. The conditioned medium of macrophages challenged with titanium particles and Ad-TNF-?-siRNA (Ti-Ad CM) reduced the mRNA expression in MC3T3-E1 cells compared to Ti CM. Based on these data, TNF-? strongly synergizes with RANKL to promote osteoclast differentiation. Furthermore, TNF-? promoted osteoclast differentiation by stimulating osteoprogenitor RANKL expression. Ad-TNF??-siRNA effectively suppressed osteoclast differentiation and bone resorption following exposure to titanium particles in the presence of RANKL. In addition, recombinant adenovirus (Ad-TNF-?-siRNA) does not have a toxic effect on the murine macrophage cell line, RAW264.7. Consequently, it can be concluded that recombinant adenovirus-mediated siRNA targeting TNF?? (Ad-TNF??-siRNA) may provide a novel therapeutic approach for the treatment of periprosthetic osteolysis. PMID:23760678

Guo, Haohui; Zhang, Jian; Hao, Shaowen; Jin, Qunhua

2013-06-11

332

Growth and sedimentation of fine particles produced in aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation.  

National Technical Information Service (NTIS)

It is known that palladium and palladium-silver fine particles were formed from deaerated aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation. Changes in particle size and with amount of particles i...

M. Hatada C. D. Jonah

1994-01-01

333

MRI findings in Hirayama’s disease: flexion-induced cervical myelopathy or intrinsic motor neuron disease?  

Microsoft Academic Search

Hirayama’s disease is a benign juvenile form of focal amyotrophy affecting the upper limbs. Previous studies have suggested\\u000a that the disorder is a neck flexion induced cervical myelopathy. We report clinical and magnetic resonance imaging findings\\u000a in nine patients with Hirayama’s disease. Cervical imaging of seven patients revealed spinal cord changes consisting of focal\\u000a atrophy and foci of signal alterations.

Rolf Schröder; Ewald Keller; Sebastian Flacke; Stephan Schmidt; Christoph Pohl; Thomas Klockgether; Uwe Schlegel

1999-01-01

334

Avian adenovirus CELO recombinants expressing VP2 of infectious bursal disease virus induce protection against bursal disease in chickens  

Microsoft Academic Search

To develop a CELO virus vector that can induce protection against infectious bursal disease, CELO viruses expressing the host-protective antigen VP2 of infectious bursal disease virus (IBDV) were constructed. In the engineered recombinants, the VP2 gene (the 441-first codons of the IBDA polyprotein) was placed under the control of the CMV promoter. Two positions in the CELO genome were chosen

Achille Francois; Christophe Chevalier; Bernard Delmas; Nicolas Eterradossi; Didier Toquin; Gaëlle Rivallan; Patrick Langlois

2004-01-01

335

Nuclear factor-? B inducing kinase is required for graft-versus-host disease  

PubMed Central

Background Donor T lymphocytes are directly responsible for graft-versus-host disease. Molecules important in T-cell function may, therefore, be appropriate targets for graft-versus-host disease therapy and/or prophylaxis. Here we analyzed whether nuclear factor-? B inducing kinase might have a role in graft-versus-host disease. Design and Methods We studied the expression of nuclear factor-? B inducing kinase in human samples from patients with graft-versus-host disease. We also explored the effect of nuclear factor-? B inducing kinase in a murine model of graft-versus-host disease using donor cells from aly/aly mice (deficient in nuclear factor-? B inducing kinase) and C57BL/6 mice (control). Results We detected expression of nuclear factor-? B inducing kinase in T-lymphocytes in the pathological lesions of patients with acute graft-versus-host disease. Mice transplanted with aly/aly T lymphocytes did not develop graft-versus-host disease at all, while mice receiving C57BL/6 cells died of a lethal form of the disease. Deficiency of nuclear factor-? B inducing kinase did not affect the engrafting ability of donor T cells, but severely impaired their expansion capacity early after transplantation, and aly/aly T cells showed a higher proportion of apoptosis than did C57BL/6 T cells. Effector T lymphocytes were the T-cell subset most affected by nuclear factor-? B inducing kinase deficiency. We also detected lower amounts of inflammatory cytokines in the serum of mice receiving aly/aly T cells than in the serum of mice receiving C57BL/6 T cells. Conclusions Our results show that nuclear factor-? B inducing kinase has a role in graft-versus-host disease by maintaining the viability of activated alloreactive T lymphocytes.

Sanchez-Valdepenas, Carmen; Casanova, Lucia; Colmenero, Isabel; Arriero, Mar; Gonzalez, Africa; Lozano, Nieves; Gonzalez-Vicent, Marta; Diaz, Miguel A.; Madero, Luis; Fresno, Manuel; Ramirez, Manuel

2010-01-01

336

The simple atomic hopping problem. Particle correlation functions with application to dipolar induced spin lattice relaxation  

Microsoft Academic Search

A model of atomic hopping is developed which takes into account the correlated motion of distinguishable particles in a lattice. These correlations are included by prohibiting multiple occupancy of a lattice site or particles to pass through each other. The method is used to derive expressions for the correlation functions which describe the motion of a single specific particle or

O. F. Sankey

1979-01-01

337

Maintenance of Medically Induced Remission of Crohn’s Disease  

Microsoft Academic Search

The natural history of Crohn’s disease is characterized by recurring flares alternating with periods of inactive disease and remission. This implies that most patients need to take medication for a large period of their life, mostly for maintenance of remission and, intermittently, additional therapy during a flare. Low-dose systemic corticosteroids are not effective in maintaining remission and should not be

Jean-Jacques Gonvers; Pascal Juillerat; Christian Mottet; Valérie Pittet; Christian Felley; John-Paul Vader; Pierre Michetti; Florian Froehlich

2007-01-01

338

Particle-Induced X-Ray Emission (PIXE) Of Silicate Coatings On High Impact Resistance Polycarbonates  

NASA Astrophysics Data System (ADS)

Particle-Induced X-ray Emission (PIXE) analysis was employed to characterize hydroxypropyl methylcellulose (HPMC) C32H60O19 polymer film via areal density measurement on silicon-based substrates utilizing the differential PIXE concept, and compared with Rutherford backscattering spectrometry (RBS) results. It is demonstrated in this paper that PIXE and RBS measurements both yield comparable results for areal densities ranging from 1018 atom/cm2 to several 1019 atom/cm2. A collection of techniques including PIXE, RBS, tapping mode atomic force microscopy (TMAFM), and contact angle analysis were used to compute surface free energy, analyze surface topography and roughness parameters, determine surface composition and areal density, and to predict the water affinity and condensation behaviors of silicates and other compounds used for high impact resistance vision ware coatings. The visor surface under study is slightly hydrophilic, with root mean square of surface roughness on the order of one nm, and surface wavelength between 200 nm and 300 nm. Water condensation can be controlled on such surfaces via polymers adsorption. HPMC polymer areal density measurement supports the analysis of the surface water affinity and topography and the subsequent control of condensation behavior. HPMC film between 1018 atom/cm2 and 1019 atom/cm2 was found to effectively alter the water condensation pattern and prevents fogging by forming a wetting layer during condensation.

Xing, Qian; Hart, M. A.; Culbertson, R. J.; Bradley, J. D.; Herbots, N.; Wilkens, Barry J.; Sell, David A.; Watson, Clarizza Fiel

2011-06-01

339

Search for wave-induced particle precipitation from lightning and transmitter sources. Master's thesis  

SciTech Connect

Wave-induced particle precipitation is introduced and examined for whistlers whose sources are within the plasmapause. The possible correlation between lightning strokes that carry positive charge to the ground and the observed Trimpi events is discussed, sudden phase and/or amplitude shifts of a received VLF signal with gradual return to predisturbed values. The thunderstorm charging mechanisms that lead to the observed charge distribution and the advection of the positively charged cirrus anvil away from the body of the thunderstorm are briefly examined. The comparative current strengths and the relative frequency of positive and negative strokes is studied for different types of thunderstorms. The magnetospheric ducting of the lightning-generated whistler wave and the interaction with trapped electrons is examined. The detectable effects the precipitating electrons have on the ionosphere is introduced. Included are testing and design of the x-ray detector and balloon-launch considerations. The problems encountered during the x-ray-detector's balloon flights are examined. The riometer and x-ray-detector data-analysis methods are mentioned. The results were negative for the data analyzed, but the limiting factors severely restricted the usable data. Possible experimental methods are mentioned.

Lundberg, J.E.

1988-01-01

340

Underwater pressure amplification of laser-induced plasma shock waves for particle removal applications  

SciTech Connect

Underwater amplification of laser-induced plasma (LIP)-generated transient pressure waves using shock tubes is introduced and demonstrated. Previously, it has been shown that LIP for noncontact particle removal is possible on the sub-100-nm level. This is now enhanced through shock tube utilization in a medium such as water by substantially increasing shock wave pressure for the same pulse energy. A shock tube constrains the volume and changes the propagation direction of the expanding plasma core by focusing a pulsed-laser beam inside a tube with a blind end, thus increasing the wave front pressure generated. Current amplification approach can reduce radiation exposure of the substrate from the shock wave because of the increased distance from the LIP core to the substrate provided by the increased pressure per unit pulse energy. For the same pulsed laser, with the aid of a shock tube, substantial levels of pressure amplitude amplification (8.95) and maximum pressure (6.48 MPa) are observed and reported.

Dunbar, Thomas J.; Cetinkaya, Cetin [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York 13699-5725 (United States) and Center for Advanced Materials Processing, Clarkson University, Potsdam, New York 13699-5725 (United States)

2007-07-30

341

Underwater pressure amplification of laser-induced plasma shock waves for particle removal applications  

NASA Astrophysics Data System (ADS)

Underwater amplification of laser-induced plasma (LIP)-generated transient pressure waves using shock tubes is introduced and demonstrated. Previously, it has been shown that LIP for noncontact particle removal is possible on the sub-100-nm level. This is now enhanced through shock tube utilization in a medium such as water by substantially increasing shock wave pressure for the same pulse energy. A shock tube constrains the volume and changes the propagation direction of the expanding plasma core by focusing a pulsed-laser beam inside a tube with a blind end, thus increasing the wave front pressure generated. Current amplification approach can reduce radiation exposure of the substrate from the shock wave because of the increased distance from the LIP core to the substrate provided by the increased pressure per unit pulse energy. For the same pulsed laser, with the aid of a shock tube, substantial levels of pressure amplitude amplification (8.95) and maximum pressure (6.48 MPa) are observed and reported.

Dunbar, Thomas J.; Cetinkaya, Cetin

2007-07-01

342

Formation of precise 2D Au particle arrays via thermally induced dewetting on pre-patterned substrates  

PubMed Central

Summary The fabrication of precise 2D Au nanoparticle arrays over a large area is presented. The technique was based on pre-patterning of the substrate before the deposition of a thin Au film, and the creation of periodic particle arrays by subsequent dewetting induced by annealing. Two types of pre-patterned substrates were used: The first comprised an array of pyramidal pits and the second an array of circular holes. For the dewetting of Au films on the pyramidal pit substrate, the structural curvature-driven diffusion cooperates with capillarity-driven diffusion, resulting in the formation of precise 2D particle arrays for films within a structure dependent thickness-window. For the dewetting of Au films on the circular hole substrate, the periodic discontinuities in the films, induced by the deposition, can limit the diffusion paths and lead to the formation of one particle per individual separated region (holes or mesas between holes), and thus, result in the evolution of precise 2D particle arrays. The influence of the pre-patterned structures and the film thickness is analyzed and discussed. For both types of pre-patterned substrate, the Au film thickness had to be adjusted in a certain thickness-window in order to achieve the precise 2D particle arrays.

Ji, Ran

2011-01-01

343

The influence of secondary flows induced by normal stress differences on the shear-induced migration of particles in concentrated suspensions  

NASA Astrophysics Data System (ADS)

It was first demonstrated experimentally by H. Giesekus in 1965 that the second normal stress difference in polymers can induce a secondary flow within the cross-section of a non-axisymmetric conduit. In this paper, we show through simulations that the same may be true for suspensions of rigid non-colloidal particles that are known to exhibit a strong negative second normal stress difference. Typically, the magnitudes of the transverse velocity components are small compared to the average axial velocity of the suspension; but the ratio of this transverse convective velocity to the shear-induced migration velocity is characterized by the shear-induced migration P which scales as B2/a2, B being the characteristic length scale of the cross-section and a being the particle radius. Since this Péclet number is kept high in suspension experiments (typically 100 to 2500), the influence of the weak circulation currents on the concentration profile can be very strong, a result that has not been appreciated in previous work. The principal effect of secondary flows on the concentration distribution as determined from simulations using the suspension balance model of Nott & Brady (J. Fluid Mech. vol. 275, 1994, p. 157) and the constitutive equations of Zarraga et al. (J. Rheol. vol. 44, 2000, p. 185) is three-fold. First, the steady-state particle concentration distribution is no longer independent of particle size; rather, it depends on the aspect ratio B/a. Secondly, the direction of the secondary flow is such that particles are swept out of regions of high streamsurface curvature, e.g. particle concentrations in corners reach a minimum rather than the local maximum predicted in the absence of such flows. Finally, the second normal stress differences lead to instabilities even in such simple geometries as plane-Poiseuille flow.

Ramachandran, Arun; Leighton, David T.

344

Assay of mutation induced in human lymphoblastoid cells by combustion-generated soot particles.  

PubMed Central

A human lymphoblastoid cell line has been used to test for mutations caused by combustion-generated soot particles and their constituent components, which are substrate carbon-black and adsorbed condensate, principally in the form of polycyclic aromatic hydrocarbons (PAH). It was found that the mutagenicity of the PAH fraction is higher when it is contacted with cells as a liquid extract than when it is supplied as a coating on soot particles. The substrate particles were found to be nonmutagenic. The rate of transfer of mutagens from the surface of particles, combined with the retention time of respirable aerosol particles, are deemed to define their mutagenic potential.

Bolsaitis, P P; Feitelberg, A S; Dekermendjian, V; Elliott, J F; Sarofim, A F; Thilly, W G

1991-01-01

345

Bone Turnover Markers Correlate with Implant fixation in a Rat Model Using LPS Doped Particles to Induced Implant Loosening1  

PubMed Central

Revision surgery for particle-induced implant loosening in total joint replacement is expected to increase dramatically over the next few decades. This study was designed to investigate if local tissue and serum markers of bone remodeling reflect implant fixation following administration of lipopolysaccharide (LPS)-doped polyethylene (PE) particles in a rat model. 24 rats received bilateral implantation of intramedullary titanium rods in the distal femur, followed by weekly bilateral intra-articular injection of either LPS-doped PE particles (n = 12) or vehicle which contained no particles (n= 12) for 12 weeks. The group in which the particles were injected had increased serum C-terminal telopeptide of type I collagen, decreased serum osteocalcin, increased peri-implant eroded surface, decreased peri-implant bone volume, and decreased mechanical pull-out strength compared to the controls. Implant fixation strength was positively correlated with peri-implant bone volume and serum osteocalcin and inversely correlated with serum C-terminal telopeptide of type I collagen, while energy to yield was positively correlated with serum osteocalcin and inversely correlated with the number of tartrate resistant acid phosphatase positive cells at the interface and the amount of peri-implant eroded surface. There was no effect on trabecular bone volume at a remote site. Thus, the particle-induced impaired fixation in this rat model was directly associated with local and serum markers of elevated bone resorption and depressed bone formation, supporting the rationale of exploring both anti-catabolic and anabolic strategies to treat and prevent particle-related implant osteolysis and loosening and indicating that serum markers may prove useful in tracking implant fixation.

Liu, Shuo; Virdi, Amarjit S.; Sena, Kotaro; Hughes, W. Frank; Sumner, Dale R.

2011-01-01

346

Detection and Reduction of the Yield Impact of Particle Induced Structure Defects at Batch Ion Implanters  

NASA Astrophysics Data System (ADS)

This paper focuses on the introduction and qualification of the in situ particle monitor so called High Yield Technology (HYT) sensor on an Axcelis NV-GSD/E 200mm high current batch implanter to detect particles in real time during the implantation process. The particles on the wafer surface were measured with Surfscan and their composition was determined by means of Energy Dispersive X-ray (EDX) analysis. A good correlation between the HYT particle counts and surface particles on dummy wafers as well as defect densities measured on wafers structured with photo resist was found. Moreover, there is a well defined linear correlation of the HYT particle counts to the yield loss. To reduce the level of particle contamination, preventive maintenance procedures were optimized and the hardware in the beam line was modified. In order to minimize structural damage from high velocity particles, the disk drive was upgraded from a belt drive to a direct drive which offers the possibility to decrease the spin speed, thus to reduce the kinetic energy of the particles. Furthermore, measures to repair the already broken structures and to reduce the impact of particles on the products were taken. Depending on the values of the HYT in situ particle monitor, rework steps on various products were introduced. The results of these actions are discussed in combination with the costs.

Schmeide, Matthias; Kokot, Michael; Franke, Dirk-Wito; Sauter, Bernd

2006-11-01

347

Clinical Features, Pathophysiology, and Treatment of Levodopa-Induced Dyskinesias in Parkinson's Disease  

PubMed Central

Dyskinetic disorders are characterized by excess of motor activity that may interfere with normal movement control. In patients with Parkinson's disease, the chronic levodopa treatment induces dyskinetic movements known as levodopa-induced dyskinesias (LID). This paper analyzed the pathophysiology, clinical manifestations, pharmacological treatments, and surgical procedures to treat hyperkinetic disorders. Surgery is currently the only treatment available for Parkinson's disease that may improve both parkinsonian motor syndrome and LID. However, this paper shows the different mechanisms involved are not well understood.

Guridi, J.; Gonzalez-Redondo, R.; Obeso, J. A.

2012-01-01

348

Clinical analysis of 275 cases of acute drug-induced liver disease  

Microsoft Academic Search

In order to analyze the causative drugs, clinical manifestation and pathological characteristics of the patients with acute\\u000a drug-induced liver disease, from January 2000 to December 2005, 275 cases diagnosed as acute drug-induced liver diseases according\\u000a to Maria Criterion and hospitalized in Zhongshan Hospital of Fudan University were retrospectively reviewed. Each was determined\\u000a by drug history, clinical symptoms and signs, laboratory

Lei Li; Wei Jiang; Jiyao Wang

2007-01-01

349

Studying the cytotoxicity and oxidative stress induced by two kinds of bentonite particles on human B lymphoblast cells in vitro.  

PubMed

The aim of the present study was to evaluate the cytotoxicity and oxidative stress induced by native and active bentonite particles (BPs) on human B lymphoblast cells using seven assays. Our results showed that the order of cytotoxicity was: active BPs>native BPs>quartz particles (DQ-12)>gypsum, according to the IC50 values in CCK-8 assay and neutral red uptake (NRU) assay. The lactate dehydrogenase (LDH) leakage, the proportions of early apoptotic cells, the reactive oxygen species (ROS) generation, the superoxide dismutase (SOD) inhibition and the malondialdehyde (MDA) release in the native and active BPs groups were significantly higher than those in the gypsum and DQ-12 groups (P<0.05 or P<0.01). Moreover, the cytotoxicity of active BPs with higher adsorption capacity of phenol was higher than that of native BPs with relatively lower adsorption capacity of phenol. The oxidative stress induced by active BPs was significantly higher than that induced by native BPs (P<0.05 or P<0.01). The water-soluble fractions of BPs did not induce the cytotoxicity and ROS generation. These findings indicated that active and native BPs could induce significantly the cytotoxic effects and oxidative stress on human B lymphoblast cells in vitro. The cytotoxic difference between active BPs and native BPs may be associated with the adsorption capacity of BPs and oxidative stress induced by BPs to a certain extent. The insoluble particle fractions may play a main role in the cytotoxic effects and oxidative stress induced by BPs. PMID:19948159

Zhang, Meibian; Lu, Yezhen; Li, Xiaoxue; Chen, Qing; Lu, Longxi; Xing, Mingluan; Zou, Hua; He, Jiliang

2009-12-03

350

Activation of the Stress Axis and Neurochemical Alterations in Specific Brain Areas by Concentrated Ambient Particle Exposure with Concomitant Allergic Airway Disease  

PubMed Central

Objective Exposure to ambient particulate matter (PM) has been linked to respiratory diseases in people living in urban communities. The mechanism by which PM produces these diseases is not clear. We hypothesized that PM could act on the brain directly to stimulate the stress axis and predispose individuals to these diseases. The purpose of this study was to test if exposure to PM can affect brain areas involved in the regulation of neuroendocrine functions, especially the stress axis, and to study whether the presence of preexisting allergic airway disease aggravates the stress response. Design Adult male rats (n = 8/group) with or without ovalbumin (OVA)-induced allergic airway disease were exposed to concentrated air particles containing PM with an aerodynamic diameter ? 2.5 ?m (PM2.5) for 8 hr, generated from ambient air in an urban Grand Rapids, Michigan, community using a mobile air research laboratory (AirCARE 1). Control animals were exposed to normal air and were treated with saline. Measurements A day after PM2.5 exposure, animals were sacrificed and the brains were removed, frozen, and sectioned. The paraventricular nucleus (PVN) and other brain nuclei were micro-dissected, and the concentrations of aminergic neurotransmitters and their metabolites were measured using high-performance liquid chromatography with electrochemical detection. Serum corticosterone levels were measured using radioimmunoassay. Results A significant increase in the concentration (mean ± SE, pg/?g protein) of norepinephrine in the PVN was produced by exposure to concentrated ambient particles (CAPs) or OVA alone (12.45 ± 2.7 and 15.84 ± 2.8, respectively) or after sensitization with OVA (19.06 ± 3.8) compared with controls (7.98 ± 1.3; p < 0.05). Serum corticosterone (mean ± SE, ng/mL) was significantly elevated in the OVA + CAPs group (242.786 ± 33.315) and in the OVA-presensitized group (242.786 ± 33.315) compared with CAP exposure alone (114.55 ± 20.9). Exposure to CAPs (alone or in combination with OVA pretreatment) can activate the stress axis, and this could probably play a role in aggravating allergic airway disease.

Sirivelu, Madhu P.; MohanKumar, Sheba M.J.; Wagner, James G.; Harkema, Jack R.; MohanKumar, Puliyur S.

2006-01-01

351

Particle-induced artifacts in the MTT and LDH viability assays  

PubMed Central

In vitro testing is a common first step in assessing combustion generated and engineered nanoparticle related health hazards. Commercially available viability assays are frequently used to compare the toxicity of different particle types and to generate dose response data. Nanoparticles, well known for having large surface areas and chemically active surfaces, may interfere with viability assays, producing a false assessment of toxicity and making it difficult to compare toxicity data. The objective of this study is to measure the extent of particle interference in two common viability assays, the MTT reduction and the lactate dehydrogenase (LDH) release assays. Diesel particles, activated carbon, flame soot, oxidized flame soot, and titanium dioxide particles are assessed for interactions with the MTT and LDH assay under cell-free conditions. Diesel particles, at concentrations as low as 0.05 ?g/ml, reduce MTT. Other particle types reduce MTT only at a concentration of 50 ?g/ml and higher. The activated carbon, soot, and oxidized soot particles bind LDH to varying extents, reducing the concentration measured in the LDH assay. The interfering effects of the particles explain in part the different toxicities measured in human bronchial epithelial cells (16HBE14o). We conclude that valid particle toxicity assessments can only be assured after first performing controls to verify that the particles under investigation do not interfere with a specific assay at the expected concentrations.

Holder, Amara L.; Goth-Goldstein, Regine; Lucas, Donald; Koshland, Catherine P.

2012-01-01

352

Role of Mutagenicity in Asbestos Fiber-Induced Carcinogenicity and Other Diseases  

Microsoft Academic Search

The cellular and molecular mechanisms of how asbestos fibers induce cancers and other diseases are not well understood. Both serpentine and amphibole asbestos fibers have been shown to induce oxidative stress, inflammatory responses, cellular toxicity and tissue injuries, genetic changes, and epigenetic alterations in target cells in vitro and tissues in vivo. Most of these mechanisms are believe to be

Sarah X. L. Huang; Marie-Claude Jaurand; David W. Kamp; John Whysner; Tom K. Hei

2011-01-01

353

Crry, a complement regulatory protein, modulates renal interstitial disease induced by proteinuria1  

Microsoft Academic Search

Crry, a complement regulatory protein, modulates renal interstitial disease induced by proteinuria.BackgroundRecent studies have suggested a role for urinary complement components in mediating tubulointerstitial damage, which is known to have a good correlation with progression of chronic renal diseases. Although accumulating evidence suggests that complement regulatory proteins play an important protective role in glomeruli, their role in renal tubules remains

Yuichi Hori; Koei Yamada; Norio Hanafusa; Toshihiro Okuda; Noriko Okada; Toshio Miyata; William G. Couser; Kiyoshi Kurokawa; Toshiro Fujita; Masaomi Nangaku

1999-01-01

354

MIF induces osteoclast differentiation and contributes to progression of periodontal disease in mice  

Microsoft Academic Search

Periodontal disease (PD) is a chronic inflammatory and alveolar bone destructive disease triggered by microorganisms from the oral biofilm. Oral inoculation of mice with the periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) induces marked alveolar bone loss and local production of inflammatory mediators, including Macrophage Migration Inhibitory Factor (MIF). The role of MIF for alveolar bone resorption during PD is not known. In

Mila Fernandes Moreira Madeira; Celso Martins Queiroz-Junior; Graciela Mitre Costa; Patrícia Campi Santos; Elcia Maria Silveira; Gustavo Pompermaier Garlet; Patrícia Silva Cisalpino; Mauro Martins Teixeira; Tarcília Aparecida Silva; Daniele da Glória Souza

355

Can Systemic Diseases Co-induce (Not Just Exacerbate) Periodontitis? A Hypothetical “Two-hit” Model  

Microsoft Academic Search

he connection between systemic diseases and chronic destructive periodontitis (CDP) has received increasing attention in recent years. A major unanswered question is how disease in one part of the body (e.g., the joints and skeletal tissues) can transmit signals to the periodontium to enhance or, as we hypothesize in this report, to co-induce CDP. The inflammatory mediators and effector molecules

L. M. Golub; J. B. Payne; R. A. Reinhardt; G. Nieman

2006-01-01

356

Quantative aspects of transfusion-transmitted retrovirus-induced lymphoproliferative disease in mice.  

PubMed

Healthy, adult C57BL/6Kh mice of both sexes were transfused with blood or blood products from syngeneic donors with retrovirus (LP-BM5)-induced lymphoproliferative disease. The disease produced in the recipients 8 weeks after transfusion was characterized by splenomegaly, disseminated lymphadenopathy, leukopenia with neutrophilia, abrogation of the primary immune response to SRBC, decreased in vitro proliferation of spleen cells co-stimulated with phorbol ester and IL-2 or ionomycin and abrogation of synergistic effect of the co stimulators. Quantitative analysis of the blood or blood products used for transfusion show that a single transfusion of 0.2 ml of PBS containing 0.2 mu 1 of whole blood or 2 microliters of plasma or 400 Ficoll-isolated peripheral blood mononuclear cells was sufficient for the inducing the disease. The results suggest that the retroviruses were present in preparations of peripheral blood mononuclear cells and plasma of mice with the disease. However, the latter was 10-fold less efficient in inducing the disease. Transfusion of 1.8 x 10(6) isolated erythrocytes failed to induce the disease suggesting a marginal role, if any, in transmission of the disease via transfusion of these cells. Thus, a simple, reliable and reproducible method for propagation of the murine lymphoproliferative disease in the laboratory has been elaborated. These results also point to some important differences with regard to blood transfusion between human and murine AIDS. PMID:8926622

Thacore, H R; Cunningham, R K; Nakeeb, S; Zaleski, M B

1995-01-01

357

Involvement of Caspase3 and GD3 Ganglioside in Ceramide-induced Apoptosis in Farber Disease  

Microsoft Academic Search

Farber's disease (FD) is a rare genetic disorder caused by ceramidase deficiency, which results in ceramide accumulation in lung, liver, colon, skeletal muscle, cartilage, and bone. Although this disease has been symptomatically characterized, little is known about its molecular pathogenetic process. Because recent studies reported that ceramide accumulation induces GD3 ganglioside formation and apoptosis, we investigated, in tissue obtained via

Felicia Farina; Francesco Cappello; Matilde Todaro; Fabio Bucchieri; Giovanni Peri; Giovanni Zummo; Giorgio Stassi

2000-01-01

358

Thiopurine-Induced Liver Injury in Patients With Inflammatory Bowel Disease: A Systematic Review  

Microsoft Academic Search

The mean prevalence of azathioprine (AZA) or 6-mercaptopurine (MP)-induced liver injury in patients with inflammatory bowel disease was approximately 3%, and the mean annual drug-induced liver disorder rate was only 1.4%. However, this low figure calculated from retrospective studies contrasts with a much higher incidence (>10%) reported by a prospective study. Thiopurine-induced hepatotoxicity can be grouped into three syndromes: hypersensitivity,

Javier P. Gisbert; Yago González-Lama; Jose Maté

2007-01-01

359

Observations of turbulence-induced new particle formation in the residual layer  

NASA Astrophysics Data System (ADS)

Aerosol particle measurements in the atmospheric boundary layer performed by a helicopter-borne measurement payload and by a lidar system from a case study during the IMPACT field campaign in Cabauw (NL) are presented. Layers of increased number concentrations of ultrafine particles were observed in the residual layer, indicating relatively recent new-particle formation. These layers were characterized by a sub-critical Richardson number and concomitant increased turbulence. Turbulent mixing is likely to lead to local supersaturation of possible precursor gases which are essential for new particle formation. Observed peaks in the number concentrations of ultrafine particles at ground level are connected to the new particle formation in the residual layer by boundary layer development and vertical mixing.

Wehner, B.; Siebert, H.; Ansmann, A.; Ditas, F.; Seifert, P.; Stratmann, F.; Wiedensohler, A.; Apituley, A.; Shaw, R. A.; Manninen, H. E.; Kulmala, M.

2010-01-01

360

Observations of turbulence-induced new particle formation in the residual layer  

NASA Astrophysics Data System (ADS)

Aerosol particle measurements in the atmospheric boundary layer performed by a helicopter-borne measurement payload and by a lidar system from a case study during the IMPACT field campaign in Cabauw (NL) are presented. Layers of increased number concentrations of ultrafine particles were observed in the residual layer, indicating relatively recent new-particle formation. These layers were characterized by a sub-critical Richardson number and concomitant increased turbulence. Turbulent mixing is likely to lead to local supersaturation of possible precursor gases which are essential for new particle formation. Observed peaks in the number concentrations of ultrafine particles at ground level are connected to the new particle formation in the residual layer by boundary layer development and vertical mixing.

Wehner, B.; Siebert, H.; Ansmann, A.; Ditas, F.; Seifert, P.; Stratmann, F.; Wiedensohler, A.; Apituley, A.; Shaw, R. A.; Manninen, H. E.; Kulmala, M.

2010-05-01

361

Gluten induces an intestinal cytokine response strongly dominated by interferon gamma in patients with celiac disease  

Microsoft Academic Search

Background & Aims: Celiac disease appears to be a T cell–mediated enteropathy induced by gluten in genetically predisposed individuals. Duodenal biopsy specimens from patients with celiac disease and histologically normal controls were investigated to see if cytokine expression is related to disease activity. Methods: Cytokine messenger RNA (mRNA) expression was determined by quantitative reverse-transcription polymerase chain reaction and in situ

Ellen M. Nilsen; Frode L. Jahnsen; Knut E. A. Lundin; Olav Fausa; Ludvig M. Sollid; Jørgen Jahnsen; Helge Scott; Per Brandtzaeg

1998-01-01

362

Induced pluripotent stem cells for retinal degenerative diseases: a new perspective on the challenges  

Microsoft Academic Search

Retinal degenerative diseases, including age-related macular degeneration and retinitis pigmentosa, are the prodominant causes\\u000a of human blindness in the world; however, these diseases are difficult to treat. Currently, knowledge on the mechanisms of\\u000a these diseases is still very limited and no radical drugs are available. Induced pluripotent stem (iPS) cells are an innovative\\u000a technology that turns somatic cells into embryonic

Zi-Bing Jin; Satoshi Okamoto; Michiko Mandai; Masayo Takahashi

2009-01-01

363

Emission-particle-induced ventilatory abnormalities in a rat model of pulmonary hypertension.  

PubMed Central

Preexistent cardiopulmonary disease in humans appears to enhance susceptibility to the adverse effects of ambient particulate matter. Previous studies in this laboratory have demonstrated enhanced inflammation and mortality after intratracheal instillation (IT) and inhalation (INH) of residual oil fly ash (ROFA) in a rat model of pulmonary hypertension induced by monocrotaline (MCT). The present study was conducted to examine the effects of ROFA in this model on ventilatory function in unanesthetized, unrestrained animals. Sixty-day-old male CD rats were injected with MCT (60 mg/kg) or vehicle (VEH) intraperitoneally 10 days before IT of ROFA (8.3 mg/kg) or saline (SAL) (control) or nose-only INH of ROFA [15 mg/m3 for 6 hr on 3 consecutive days or air (control)]. At 24 and 72 hr after exposure, rats were studied individually in a simultaneous gas uptake/whole-body plethysmograph. Lungs were removed at 72 hr for histology. Pulmonary test results showed that tidal volume (VT) decreased 24 hr after IT of ROFA in MCT-treated rats. Breathing frequency, minute volume (VE), and the ventilatory equivalent for oxygen increased in MCT- and VEH-treated rats 24 hr after IT or INH of ROFA and remained elevated 72 hr post-IT. O2 uptake (VO2) decreased after IT of ROFA in MCT-treated rats. Carbon monoxide uptake decreased 24 hr after IT of ROFA, returning to control values in VEH-treated rats but remaining low in MCT-treated rats 72 hr post-IT. ROFA exposure induced histologic changes and abnormalities in several ventilatory parameters, many of which were enhanced by MCT treatment.

Gardner, Sarah Y; McGee, John K; Kodavanti, Urmila P; Ledbetter, Allen; Everitt, Jeffrey I; Winsett, Darrell W; Doerfler, Donald L; Costa, Daniel L

2004-01-01

364

Linear flow induced in fluid particle suspension by an infinite differentially rotating disk  

Microsoft Academic Search

The steady, axisymmetric laminar flow of a homogeneous incompressible fluid with suspended particles occupying the half-infinite\\u000a space over a differentially rotating rigid plane boundary is analyzed in this paper. The effect of suspended particles is\\u000a described by two parametersf and ?. The mass concentration parameterf is a measure of the concentration of suspended dust particles. The interaction parameter ? is

C N B Rao; V Vasudeva Murty; V Somaraju

1991-01-01

365

Human Pompe disease-induced pluripotent stem cells for pathogenesis modeling, drug testing and disease marker identification.  

PubMed

Pompe disease is caused by autosomal recessive mutations in the acid alpha-glucosidase (GAA) gene, which encodes GAA. Although enzyme replacement therapy has recently improved patient survival greatly, the results in skeletal muscles and for advanced disease are still not satisfactory. Here, we report the derivation of Pompe disease-induced pluripotent stem cells (PomD-iPSCs) from two patients with different GAA mutations and their potential for pathogenesis modeling, drug testing and disease marker identification. PomD-iPSCs maintained pluripotent features and had low GAA activity and high glycogen content. Cardiomyocyte-like cells (CMLCs) differentiated from PomD-iPSCs recapitulated the hallmark Pompe disease pathophysiological phenotypes, including high levels of glycogen and multiple ultrastructural aberrances. Drug rescue assessment showed that exposure of PomD-iPSC-derived CMLCs to recombinant human GAA reversed the major pathologic phenotypes. Furthermore, l-carnitine treatment reduced defective cellular respiration in the diseased cells. By comparative transcriptome analysis, we identified glycogen metabolism, lysosome and mitochondria-related marker genes whose expression robustly correlated with the therapeutic effect of drug treatment in PomD-iPSC-derived CMLCs. Collectively, these results demonstrate that PomD-iPSCs are a promising in vitro disease model for the development of novel therapeutic strategies for Pompe disease. PMID:21926084

Huang, Hsiang-Po; Chen, Pin-Hsun; Hwu, Wuh-Liang; Chuang, Ching-Yu; Chien, Yin-Hsiu; Stone, Lee; Chien, Chung-Liang; Li, Li-Tzu; Chiang, Shu-Chuan; Chen, Hsin-Fu; Ho, Hong-Nerng; Chen, Chung-Hsuan; Kuo, Hung-Chih

2011-09-15

366

Low doses of alpha particles do not induce sister chromatid exchanges in bystander Chinese hamster cells defective in homologous recombination  

SciTech Connect

We reported previously that the homologous recombinational repair (HRR)-deficient Chinese hamster mutant cell line irs3 (deficient in the Rad51 paralog Rad51C) showed only a 50% spontaneous frequency of sister chromatid exchange (SCE) as compared to parental wild-type V79 cells. Furthermore, when irradiated with very low doses of alpha particles, SCEs were not induced in irs3 cells, as compared to a prominent bystander effect observed in V79 cells (Nagasawa et al., Radiat. Res. 164, 141-147, 2005). In the present study, we examined additional Chinese hamster cell lines deficient in the Rad51 paralogs Rad51C, Rad51D, Xrcc2, and Xrcc3 as well as another essential HRR protein, Brca2. Spontaneous SCE frequencies in non-irradiated wild-type cell lines CHO, AA8 and V79 were 0.33 SCE/chromosome, whereas two Rad51C-deficient cell lines showed only 0.16 SCE/chromosome. Spontaneous SCE frequencies in cell lines defective in Rad51D, Xrcc2, Xrcc3, and Brca2 ranged from 0.23-0.33 SCE/chromosome, 0-30% lower than wild-type cells. SCEs were induced significantly 20-50% above spontaneous levels in wild-type cells exposed to a mean dose of 1.3 mGy of alpha particles (<1% of nuclei traversed by an alpha particle). However, induction of SCEs above spontaneous levels was minimal or absent after {alpha}-particle irradiation in all of the HRR-deficient cell lines. These data suggest that Brca2 and the Rad51 paralogs contribute to DNA damage repair processes induced in bystander cells (presumably oxidative damage repair in S-phase cells) following irradiation with very low doses of alpha particles.

Nagasawa, H; Wilson, P F; Chen, D J; Thompson, L H; Bedford, J S; Little, J B

2007-10-26

367

Experimental wake-induced oscillations of dust particles in a rf plasma  

NASA Astrophysics Data System (ADS)

Self-excited nonlinear oscillations of dust particles floating in a rf plasma are described. Small assemblies of two and three dust particles are levitated in the sheath, above the driven electrode due to the equilibrium between the electrostatic, gravitational, friction and ion drag forces. In a very narrow range of pressures, spontaneous oscillations of the particles are observed. A heating mechanism based on the ion focusing effect produced by the particles as ions flow vertically past them in the plasma sheath, is proposed to explain the oscillations.

Tico?, C. M.; Smith, P. W.; Shukla, P. K.

2003-12-01

368

Hydrogen absorption induced metal deposition on palladium and palladium-alloy particles  

DOEpatents

The present invention relates to methods for producing metal-coated palladium or palladium-alloy particles. The method includes contacting hydrogen-absorbed palladium or palladium-alloy particles with one or more metal salts to produce a sub-monoatomic or monoatomic metal- or metal-alloy coating on the surface of the hydrogen-absorbed palladium or palladium-alloy particles. The invention also relates to methods for producing catalysts and methods for producing electrical energy using the metal-coated palladium or palladium-alloy particles of the present invention.

Wang, Jia X. (East Setauket, NY); Adzic, Radoslav R. (East Setauket, NY)

2009-03-24

369

Labetalol-induced Peyronie's disease? A case report.  

PubMed

Peyronie's disease (induratio penis plastica) has been observed in a 58-year-old man 8 months after initiation of treatment with the new combined alpha- and beta-blocking agent, labetalol. During the last 2 months before onset of symptoms he had received 2400 mg labetalol daily. He showed no other signs of abnormal fibrous tissue production and the ANF test was negative. Cessation of the drug revealed no improvement. Peyronie's disease has also been observed in relation to treatment with propranolol, practolol and metoprolol and might be due to an impaired balance between alpha- and beta-receptors in connective tissue, but there may also be an immunological basis for the fibrosis. A possible coincidence is stressed, as the ages of the reported cases are within the range where this disease most often develops. PMID:231377

Kristensen, B O

1979-01-01

370

Size-partitioning of an urban aerosol to identify particle determinants involved in the proinflammatory response induced in airway epithelial cells  

PubMed Central

Background The contribution of air particles in human cardio-respiratory diseases has been enlightened by several epidemiological studies. However the respective involvement of coarse, fine and ultrafine particles in health effects is still unclear. The aim of the present study is to determine which size fraction from a chemically characterized background aerosol has the most important short term biological effect and to decipher the determinants of such a behaviour. Results Ambient aerosols were collected at an urban background site in Paris using four 13-stage low pressure cascade impactors running in parallel (winter and summer 2005) in order to separate four size-classes (PM0.03–0.17 (defined here as ultrafine particles), PM0.17–1 (fine), PM1–2.5(intermediate) and PM2.5–10 (coarse)). Accordingly, their chemical composition and their pro-inflammatory potential on human airway epithelial cells were investigated. Considering isomass exposures (same particle concentrations for each size fractions) the pro-inflammatory response characterized by Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF) release was found to decrease with aerosol size with no seasonal dependency. When cells were exposed to isovolume of particle suspensions in order to respect the particle proportions observed in ambient air, the GM-CSF release was maximal with the fine fraction. In presence of a recombinant endotoxin neutralizing protein, the GM-CSF release induced by particles is reduced for all size-fractions, with exception of the ultra-fine fraction which response is not modified. The different aerosol size-fractions were found to display important chemical differences related to the various contributing primary and secondary sources and aerosol age. The GM-CSF release was correlated to the organic component of the aerosols and especially its water soluble fraction. Finally, Cytochrome P450 1A1 activity that reflects PAH bioavailability varied as a function of the season: it was maximal for the fine fraction in winter and for the ultrafine fraction in summer. Conclusion In the frame of future regulations, a particular attention should thus be paid to the ultrafine/fine (here referred to as PM1) fraction due to their overwhelming anthropogenic origin and predominance in the urban aerosol and their pro-inflammatory potential.

Ramgolam, Kiran; Favez, Olivier; Cachier, Helene; Gaudichet, Annie; Marano, Francelyne; Martinon, Laurent; Baeza-Squiban, Armelle

2009-01-01

371

Evidence for immunological (allergic) mechanisms in a subgroup of patients with phenprocoumon-induced liver disease  

Microsoft Academic Search

Purpose  Phenprocoumon-induced liver injury is a rare complication of oral anticoagulation. The mechanisms leading to this side effect\\u000a are not entirely clear. Here we present data that at least in a subgroup of patients in whom phenprocoumon-induced liver disease\\u000a was suspected, immunological processes may play an important role.\\u000a \\u000a \\u000a \\u000a Patients and methods  Thirty patients with suspected phenprocoumon-induced liver disease from different hospitals in

Reinhild Klein

2009-01-01

372

Drug-Induced Pulmonary Vascular Disease--Mechanisms and Clinical Patterns  

PubMed Central

An extensive vascular surface area places the lungs at risk for damage by blood-borne drugs. Drug-induced pulmonary vascular disease may present clinically as acute pulmonary edema, pulmonary edema followed by diffuse interstitial lung disease, pulmonary vascular occlusion, pulmonary hypertension or hemorrhage. It is important to recognize these reactions as drug-related because many are reversible with discontinuation of the drug and supportive therapy. Failure to recognize drug-induced pulmonary vascular disease can lead to significant morbidity and, in some cases, death. ImagesFigure 1.Figure 2.Figure 2.Figure 3.

Kumar, Kusum; Holden, William E.

1986-01-01

373

Multifractal analysis of particles produced in 197Au, 32S and 16O induced interactions at high energies  

Microsoft Academic Search

We analyse the multifractal structure of moments Gq in terms of a new variable X on data of 197Au, 32S and 16O induced interactions with emulsion nuclei and Monte Carlo generated samples. The dynamical properties of the produced particles are mapped onto multifractal spectra. We compare ln langleGrangle in experimental data of 197Au, 32S and 16O with pure statistical fluctuations.

M. I. Adamovich; M. M. Aggarwal; Y. A. Alexandrov; R. Amirikas; N. P. Andreeva; F. A. Avetyan; S. K. Badyal; A. M. Bakich; E. S. Basova; K. B. Bhalla; A. Bhasin; V. S. Bhatia; V. G. Bogdanov; V. Bradnova; V. I. Bubnov; X. Cai; I. Y. Chasnikov; G. M. Chen; L. P. Chernova; M. M. Chernyavski; S. Dhamija; K. El Chenawi; D. Felea; S. Q. Feng; A. S. Gaitinov; E. R. Ganssauge; S. Garpman; S. G. Gerassimov; A. Gheata; M. Gheata; J. Grote; K. G. Gulamov; S. K. Gupta; V. K. Gupta; M. Haiduc; D. Hasegan; Z. R. Hu; B. Jakobsson; L. Just; E. K. Kanygina; M. Karabova; S. P. Kharlamov; Y. C. Kim; A. D. Kovalenko; S. A. Krasnov; V. Kumar; V. G. Larionova; C. G. Lee; F. G. Lepekhin; H. Liu; O. V. Levitskaya; Y. X. Li; L. Liang; L. S. Liu; Z. G. Liu; S. Lokanathan; J. J. Lord; Y. Lu; N. S. Lukicheva; W. Li; S. B. Luo; L. K. Mangotra; N. A. Marutyan; I. S. Mittra; A. K. Musaeva; S. Z. Nasyrov; V. S. Navotny; P. Nilsson; J. Nystrand; G. I. Orlova; I. Otterlund; A. Pavukova; L. S. Peak; N. G. Peresadko; N. V. Petrov; V. A. Plyushchev; W. Y. Qian; Y. M. Qin; R. Raniwala; N. K. Rao; J. T. Rhee; M. Roeper; V. V. Rusakova; N. Saidkhanov; N. A. Salmanova; L. G. Sarkisova; V. R. Sarkisyan; A. M. Seitimbetov; D. M. Seliverstov; R. Sethi; C. I. Shakhova; B. B. Simonov; B. Singh; D. Skelding; V. I. Skorobogatova; K. Söderström; E. Stenlund; L. N. Svechnikova; A. M. Tawfik; M. Tothova; M. I. Tretyakova; T. P. Trofimova; U. I. Tuleeva; V. Vashisht; S. Vokal; J. Vrlakova; H. Q. Wang; S. H. Wang; X. R. Wang; Z. Q. Weng; R. J. Wilkes; T. Wu; C. B. Yang; Z. B. Yin; L. Z. Yu; Y. L. Yu; D. H. Zhang; P. Y. Zheng; S. I. Zhokhova; D. C. Zhou

1998-01-01

374

Adsorption behaviors of organic vapors using mesoporous silica particles made by evaporation induced self-assembly method  

Microsoft Academic Search

Spherical mesoporous silica materials with controllable surface area and uniform pore size were synthesized via evaporation induced self-assembly (EISA) method in this study. Both well-ordered and less-ordered mesoporous silica particle (MSP) adsorbents were made via adjusting the surfactant\\/silica precursor molar ratio. And the relationships between the physical characteristics of MSP adsorbents and the acetone adsorption behaviors were examined for the

Chin-Te Hung; Hsunling Bai

2008-01-01

375

Induced self-energy on a static scalar charged particle in the spacetime of a global monopole with finite core  

Microsoft Academic Search

We analyze the induced self-energy and self-force on a scalar point-like charged test particle placed at rest in the spacetime of a global monopole admitting a general spherically symmetric inner structure to it. In order to develop this analysis we calculate the three-dimensional Green's function associated with this physical system. We explicitly show that for points outside the monopole's core

D. Barbosa; U. de Freitas; E. R. Bezerra de Mello

2011-01-01

376

Effects of thin, semi-rigid coatings on the adhesion-induced deformations between rigid particles and soft substrates  

Microsoft Academic Search

Glass particles, having nominal radii of approximately 20 ?m, were deposited onto polyurethane substrates, which had been overcoated with a 5-?m-thick thermoplastic layer, and the surface-force-induced contact radii were measured using scanning electron microscopy. It was found that the size of the deformations depends only on the modulus of the coating and not on the modulus of the underlying substrate.

D. S. Rimai; L. P. DeMejo; W. B. Vreeland; R. C. Bowen; S. R. Gaboury; M. W. Urban

1993-01-01

377

Motorcycle Exhaust Particles Induce IL8 Production Through NF-?B Activation in Human Airway Epithelial Cells  

Microsoft Academic Search

Motorcycle exhaust particles (MEP) are among the major air pollutants, especially in urban area of Taiwan. In our previous study, data showed that MEP induce proinflammatory and proallergic response profiles in BALB\\/c mice. Effects of MEP on interleukin (IL)-8 production in A549 human airway epithelial cells were further investigated in this study. It was found that MEP enhanced IL-8 protein

Chen-Chen Lee; Yu-Wen Cheng; Jaw-Jou Kang

2005-01-01

378

TIME COURSE OF QUARTZ AND TiO 2 PARTICLE-INDUCED PULMONARY INFLAMMATION AND NEUTROPHIL APOPTOTIC RESPONSES IN RATS  

Microsoft Academic Search

Apoptosis, or programmed cell death, has been reported to play an important role in the resolu- tion of pulmonary inammation. This study was undertaken to investigate the role of apoptosis in resolving particle-induced lung inammatory responses in exposed rats, using a dose-response=time course experimental design. Groups of rats were exposed via intratracheal instillation to 0, 0.5, 1, 5, 10, or

Donna D. Zhang; Mark A. Hartsky; David B. Warheit

2002-01-01

379

Low doses of alpha particles do not induce sister chromatid exchanges in bystander Chinese hamster cells defective in homologous recombination  

Microsoft Academic Search

We reported previously that the homologous recombinational repair (HRR)-deficient Chinese hamster mutant cell line irs3 (deficient in the Rad51 paralog Rad51C) showed only a 50% spontaneous frequency of sister chromatid exchange (SCE) as compared to parental wild-type V79 cells. Furthermore, when irradiated with very low doses of alpha particles, SCEs were not induced in irs3 cells, as compared to a

Hatsumi Nagasawa; Paul F. Wilson; David J. Chen; Larry H. Thompson; Joel S. Bedford; John B. Little

2008-01-01

380

Low doses of alpha particles do not induce sister chromatid exchanges in bystander Chinese hamster cells defective in homologous recombination  

Microsoft Academic Search

We reported previously that the homologous recombinational repair (HRR)-deficient Chinese hamster mutant cell line irs3 (deficient in the Rad51 paralog Rad51C) showed only a 50% spontaneous frequency of sister chromatid exchange (SCE) as compared to parental wild-type V79 cells. Furthermore, when irradiated with very low doses of alpha particles, SCEs were not induced in irs3 cells, as compared to a

H Nagasawa; P F Wilson; D J Chen; L H Thompson; J S Bedford; J B Little

2007-01-01

381

Oral vaccination of mice with human papillomavirus virus-like particles induces systemic virus-neutralizing antibodies  

Microsoft Academic Search

To assess whether oral vaccination against human papillomavirus (HPV) may be feasible, we administered HPV virus-like particles (VLPs) to mice by gavage. Enzyme-linked immunosorbent assay (ELISA) results indicated that serum anti-VLP immunoglobulin G (IgG) and IgA antibodies were induced after oral vaccination, and these responses demonstrated antigenic specificities that were conformationally dependent and restricted according to HPV genotype. Importantly, orally

Robert C Rose; Susan Wilson; JoAnn A Suzich; Edward Rybicki; Anna-Lise Williamson

1999-01-01

382

Towards Simulating Charged Particles in a Magnetic Field with a Bose-Einstein Condensate Using Light-induced Vector potentials  

Microsoft Academic Search

We experimentally study light-induced gauge potentials in a ^87Rb Bose-Einstein condensate. The atoms, dressed by a two-photon Raman coupling between the three F=1 hyperfine ground states, acquire a controllable quasi-momentum (static in the lab frame). We adiabatically load the atoms into the lowest energy dressed state, whose measured spin and momentum decomposition agrees quantitatively with a simple single- particle model.

Yu-Ju Lin; Robert Compton; Abigail Perry; William Phillips; Trey Porto; Ian Spielman

2009-01-01

383

Mildly oxidized LDL particle subspecies are distinct in their capacity to induce apoptosis in endothelial cells: role of lipid hydroperoxides  

Microsoft Academic Search

The risk of atherosclerosis is intimately related to the heterogeneity of low-density lipoprotein (LDL) particles. The potential relationship between oxidative modification of distinct LDL subspecies and induction of apoptosis in arterial wall cells is indeterminate. The capacity of light LDL3 versus dense LDL5 to induce cytotoxicity in endothelial cells as a function of the degree of copper-mediated oxidation was compared.

Anatol Kontush; Laurent Chancharme; Isabelle Escargueil-Blanc; Patrice Therond; Robert Salvayre; Anne Nègre-Salvayre; M. John Chapman

2002-01-01

384

Curcumin reduces ?-synuclein induced cytotoxicity in Parkinson's disease cell model  

Microsoft Academic Search

BACKGROUND: Overexpression and abnormal accumulation of aggregated ?-synuclein (?S) have been linked to Parkinson's disease (PD) and other synucleinopathies. ?S can misfold and adopt a variety of morphologies but recent studies implicate oligomeric forms as the most cytotoxic species. Both genetic mutations and chronic exposure to neurotoxins increase ?S aggregation and intracellular reactive oxygen species (ROS), leading to mitochondrial dysfunction

Min S Wang; Shanta Boddapati; Sharareh Emadi; Michael R Sierks

2010-01-01

385

Drug-induced impulse control disorders in Parkinson's disease.  

PubMed

Dopamine replacement treatment with excessive or aberrant dopamine receptor stimulation can cause behavioral disturbances in Parkinson's disease, comprising dopamine dysregulation syndrome, punding, and impulse control disorders. Common impulse control disorders are compulsive buying, pathological gambling, binge eating, hypersexuality, and compulsive reckless driving. PMID:21560063

Reiff, J; Jost, W H

2011-05-01

386

Mechanisms of lead-induced hypertension and cardiovascular disease  

PubMed Central

Lead is a ubiquitous environmental toxin that is capable of causing numerous acute and chronic illnesses. Population studies have demonstrated a link between lead exposure and subsequent development of hypertension (HTN) and cardiovascular disease. In vivo and in vitro studies have shown that chronic lead exposure causes HTN and cardiovascular disease by promoting oxidative stress, limiting nitric oxide availability, impairing nitric oxide signaling, augmenting adrenergic activity, increasing endothelin production, altering the renin-angiotensin system, raising vasoconstrictor prostaglandins, lowering vasodilator prostaglandins, promoting inflammation, disturbing vascular smooth muscle Ca2+ signaling, diminishing endothelium-dependent vasorelaxation, and modifying the vascular response to vasoactive agonists. Moreover, lead has been shown to cause endothelial injury, impede endothelial repair, inhibit angiogenesis, reduce endothelial cell growth, suppress proteoglycan production, stimulate vascular smooth muscle cell proliferation and phenotypic transformation, reduce tissue plasminogen activator, and raise plasminogen activator inhibitor-1 production. Via these and other actions, lead exposure causes HTN and promotes arteriosclerosis, atherosclerosis, thrombosis, and cardiovascular disease. In conclusion, studies performed in experimental animals, isolated tissues, and cultured cells have provided compelling evidence that chronic exposure to low levels of lead can cause HTN, endothelial injury/dysfunction, arteriosclerosis, and cardiovascular disease. More importantly, these studies have elucidated the cellular and molecular mechanisms of lead's action on cardiovascular/renal systems, a task that is impossible to accomplish using clinical and epidemiological investigations alone.

Vaziri, Nosratola D.

2008-01-01

387

Dopamine-Induced Nonmotor Symptoms of Parkinson's Disease  

PubMed Central

Nonmotor symptoms of Parkinson's disease (PD) may emerge secondary to the underlying pathogenesis of the disease, while others are recognized side effects of treatment. Inevitably, there is an overlap as the disease advances and patients require higher dosages and more complex medical regimens. The non-motor symptoms that emerge secondary to dopaminergic therapy encompass several domains, including neuropsychiatric, autonomic, and sleep. These are detailed in the paper. Neuropsychiatric complications include hallucinations and psychosis. In addition, compulsive behaviors, such as pathological gambling, hypersexuality, shopping, binge eating, and punding, have been shown to have a clear association with dopaminergic medications. Dopamine dysregulation syndrome (DDS) is a compulsive behavior that is typically viewed through the lens of addiction, with patients needing escalating dosages of dopamine replacement therapy. Treatment side effects on the autonomic system include nausea, orthostatic hypotension, and constipation. Sleep disturbances include fragmented sleep, nighttime sleep problems, daytime sleepiness, and sleep attacks. Recognizing the non-motor symptoms that can arise specifically from dopamine therapy is useful to help optimize treatment regimens for this complex disease.

Park, Ariane; Stacy, Mark

2011-01-01

388

Comparative Elongated Mineral Particle Toxicology & Erionite?s Apparent  High Potency for Inducing Mesothelioma  

EPA Science Inventory

Recent NHEERL research under EPA's Libby Action Plan has determined that elongated particle relative potency for rat pleural mesothelioma is best predicted on the basis of total external surface area (TSA) of slightly acid leached test samples which simulate particle bio-durabili...

389

CONCENTRATED AMBIENT AIR PARTICLES INDUCE PULMONARY INFLAMMATION IN HEALTHY HUMAN VOLUNTEERS  

EPA Science Inventory

We tested the hypothesis that exposure of healthy volunteers to concentrated ambient particles (CAPS) is associated with an influx of inflammatory cells into the lower respiratory tract. Thirty-eight volunteers were exposed to either filtered air or particles concentrated fro...

390

The shear induced motion of a particle over a rough plane  

NASA Astrophysics Data System (ADS)

The interaction of a spherical particle with a fixed rough bed in a simple shear viscous flow is studied experimentally. The shear flow is produced using an annular Couette cell which has a rectangular cross section and is filled with silicon oil. The rough bed consists of a monolayer of glued particles, randomly positioned on an annular ring placed on the bottom of the channel. By means of digital image particle tracking, the position of the test particle was obtained from a high speed video imaging system. The velocity of the particle was calculated in the stream, cross stream and vertical directions. Values of the mean and fluctuating components were calculated for a wide range of parameters, varying the particle size and density, the fluid viscosity and the mean shear, ?. It was found that the normalized stream-wise mean particle velocity U/US, where US is the Stokes settling velocity, depends only on the dimensionless shear rate, ?=??/(??g d), also called Shields number. This is consistent with the fact that the particle Reynolds number was smaller than 1 for most experiments. A simple model is proposed, based on a balance of hydrodynamic forces and a lumped friction force. Good agreement is found between the model predictions and the experiments.

Charru, F.; Zenit, R.

2005-11-01

391

Vortex Formation in a Shock-Accelerated Gas Induced by Particle Seeding  

Microsoft Academic Search

An instability forms in gas of constant density (air) with an initial nonuniform seeding of small particles or droplets as a planar shock wave passes through the two-phase medium. The seeding nonuniformity is produced by vertical injection of a slow-moving jet of air premixed with glycol droplets or smoke particles into the test section of a shock tube, with the

Peter Vorobieff; Michael Anderson; Joseph Conroy; Ross White; C. Randall Truman; Sanjay Kumar

2011-01-01

392

OXIDATIVE STRESS AND LIPID MEDIATORS INDUCED IN ALVEOLAR MACHROPHAGES BY ULTRAFINE PARTICLES  

EPA Science Inventory

In ambient aerosols, ultrafine particles (UFP) and their agglomerates are considered to be major factors contributing to adverse health effects. Reactivity of agglomerated UFP of elemental carbon (EC), Printex 90, Printex G, and diesel exhaust particles (DEP) was evaluated by the...

393

The formation of chlorine-induced alterations in daguerreotype image particles: a high resolution SEM-EDS study  

NASA Astrophysics Data System (ADS)

The daguerreotype image, composed of nanosized silver-mercury or silver-mercury-gold amalgam particles formed on a polished silver substrate, is particularly sensitive to deterioration by chlorine-containing compounds resulting in the formation of AgCl that generates redeposited silver upon exposure to UV and visible lights. In the present study, alterations caused by chlorides on daguerreotype test samples prepared following 19th century recipes were studied. The dependence of variations in the production steps of daguerreotypes, such as multiple sensitization and gilding, on the impact of the exposure to chlorine were analyzed by scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDS) and atomic force microscopy (AFM), complemented by X-ray fluorescence (XRF) and Raman spectroscopy. It was observed that AgCl nucleates on the image particles and in the substrate defects, regardless of the particle density or the sensitization process. In gilded samples, Au was observed over the image particles and the polished silver substrate as a tightly packed grainy layer, which conformably follows the polishing irregularities. For the first time it is shown that Au preferentially accumulates on top of the image particles. This gold layer does not protect the image from chlorine-induced deterioration.

Centeno, Silvia A.; Schulte, Franziska; Kennedy, Nora W.; Schrott, Alejandro G.

2011-10-01

394

Driven hard-core fluid on a ladder: shear-induced particle redistribution  

NASA Astrophysics Data System (ADS)

We study driven particle systems with excluded volume interactions on a two-level ladder with periodic boundaries, using Monte Carlo simulation, cluster mean-field theory, and exact (numerical) solution of the master equation. Particles on one level are subject to a drive that forbids motion along one direction, while in the other level the motion is unbiased; particles may jump between levels. Despite the symmetry of the rates for transitions between layers, the associated particle densities are unequal: at low densities there is an excess of particles in the non-driven layer, while at higher densities the tendency is reversed. Similar results are found for an off-lattice model. We quantify the reduction in the stationary entropy caused by the drive.

Dickman, Ronald; Vidigal, Ronaldo

2007-03-01

395

Are Thiopurines Always Contraindicated After Thiopurine Induced Pancreatitis in Inflammatory Bowel Disease?  

PubMed

BACKGROUND AND AIMS:: Thiopurine use in Inflammatory Bowel Disease (IBD) is well established for maintenance of disease remission. Approximately 3% of patients with IBD develop thiopurine induced pancreatitis, as an idiosyncratic reaction. Patients diagnosed with thiopurine induced pancreatitis are largely considered not candidates for future use of this drug. We hypothesize that previous thiopurine induced pancreatitis is not an absolute contraindication to retrialing a different thiopurine. METHODS:: Retrospective chart review of those patients with IBD in whom thiopurines were successfully reintroduced following suspected thiopurine induced pancreatitis. The patients were all cared for in two Australasian Paediatric IBD services. Four cases are presented of thiopurine induced pancreatitis appropriately related temporally to azathioprine commencement, with no other apparent cause of pancreatitis identified. All these patients were trialled on 6-Mercaptopurine according to clinical need and this was well tolerated in all cases. CONCLUSIONS:: This report is the largest case series to date focusing on the reintroduction of a thiopurine following suspected thiopurine induced pancreatitis. All patients had a very typical presentation of thiopurine induced pancreatitis. This case series should call into question the assumption that suspected thiopurine induced pancreatitis is an absolute contraindication to the future use of this class of drug. Cautious reintroduction of a thiopurine, in a controlled setting, should be considered in certain circumstances. The clinical relevance of this option is most marked in patients with complicated disease requiring long-term immunosuppression, in whom other therapies are poorly tolerated or contraindicated. PMID:23783022

Ledder, Oren D; Lemberg, Daniel A; Ooi, Chee Y; Day, Andrew S

2013-06-17

396

Low doses of alpha particles do not induce sister chromatid exchanges in bystander Chinese hamster cells defective in homologous recombination.  

PubMed

We reported previously that the homologous recombinational repair (HRR)-deficient Chinese hamster mutant cell line irs3 (deficient in the Rad51 paralog Rad51C) showed only a 50% spontaneous frequency of sister chromatid exchange (SCE) as compared to parental wild-type V79 cells. Furthermore, when irradiated with very low doses of alpha particles, SCEs were not induced in irs3 cells, as compared to a prominent bystander effect observed in V79 cells [H. Nagasawa, Y. Peng, P.F. Wilson, Y.C. Lio, D.J. Chen, J.S. Bedford, J.B. Little, Role of homologous recombination in the alpha-particle-induced bystander effect for sister chromatid exchanges and chromosomal aberrations, Radiat. Res. 164 (2005) 141-147]. In the present study, we examined additional Chinese hamster cell lines deficient in the Rad51 paralogs Rad51C, Rad51D, Xrcc2, and Xrcc3 as well as another essential HRR protein, Brca2. Spontaneous SCE frequencies in non-irradiated wild-type cell lines CHO, AA8 and V79 were 0.33SCE/chromosome, whereas two Rad51C-deficient cell lines showed only 0.16SCE/chromosome. Spontaneous SCE frequencies in cell lines defective in Rad51D, Xrcc2, Xrcc3, and Brca2 ranged from 0.23 to 0.33SCE/chromosome, 0-30% lower than wild-type cells. SCEs were induced significantly 20-50% above spontaneous levels in wild-type cells exposed to a mean dose of 1.3mGy of alpha particles (<1% of nuclei traversed by an alpha particle). However, induction of SCEs above spontaneous levels was minimal or absent after alpha-particle irradiation in all of the HRR-deficient cell lines. These data suggest that Brca2 and the Rad51 paralogs contribute to DNA damage repair processes induced in bystander cells (presumably oxidative damage repair in S-phase cells) following irradiation with very low doses of alpha particles. PMID:18182331

Nagasawa, Hatsumi; Wilson, Paul F; Chen, David J; Thompson, Larry H; Bedford, Joel S; Little, John B

2008-01-07

397

Herpesvirus saimiri-induced lymphoproliferative disease in howler monkeys.  

PubMed

Four of 5 howler monkeys (Alouatta caraya) experimentally infected with Herpesvirus saimiri (HVS) developed a rapidly fatal malignant lymphoma accompanied by peripheral T-cell lymphocytosis. HVS was isolated from fresh and tissue cultured blood and tissue lymphocytes and from cell cultures derived from nonlymphoid organs. Humoral antibodies against HVS-induced antigens were detected in the sera of the animals. The in vitro response of the peripheral blood lymphocytes to mitogenic stimulants was depressed following HVS infection. PMID:195067

Rangan, S R; Martin, L N; Enright, F M; Abee, C R

1977-07-01

398

Induced Systemic Resistance in Biocontrol of Plant Diseases  

Microsoft Academic Search

\\u000a Induction of resistance to pathogens by some strains of plant growth-promoting rhizobacteria (PGPR) and other microorganisms\\u000a is termed induced systemic resistance (ISR). In contrast to systemic acquired resistance, ISR develops as a result of the\\u000a colonization of plant roots by PGPR and other plant-beneficial microorganisms. ISR is mediated predominantly by a jasmonate-\\u000a or ethylene-sensitive pathway. Some strains of Pseudomonas, Bacillus,

Sudhamoy Mandal; Ramesh C. Ray

399

Immunologically-mediated toxin-induced renal disease  

Microsoft Academic Search

There is still a long way to go before all the mechanisms responsible for drug-induced immune kidney lesions will be explained.\\u000a However, the notion that T-cell activation in addition to T-cell receptor-MHC peptide interactions also requires a tissue\\u000a environment is an important concept for better understanding immunopathogenic mechanisms. For example, it is noteworthy that\\u000a a toxic effect of the drugs

Lucette Pelletier; Magali Savignac; Philippe Druet

400

Beneficial Effect of Oxytetracycline in Cortisone-induced Wasting Disease  

Microsoft Academic Search

INJECTION of hydrocortisone into new-born mice results in the development of a wasting syndrome similar to that seen in mice after neonatal thymectomy1. McIntire et al.2 suggested that the wasting disease seen in neonatally thymectomized mice is associated with an infectious process as the wasting syndrome does not appear in neonatally thymectomized germ-free mice. Administration of antibiotics to neonatally thymectomized

James T. Duhig

1965-01-01

401

Radiation-Induced Heart Disease: A Clinical Update  

PubMed Central

Cardiovascular diseases and cancer are the two leading causes of morbidity and mortality worldwide. Improvement in cancer therapy has led to increasing number of cancer survivors, some of whom may suffer from adverse cardiovascular effects of radiation therapy. Longterm followup is essential, as the cardiac complication may manifest years after completion of radiation therapy. In this paper, we have discussed the cardiovascular effects of radiation therapy.

Yusuf, Syed Wamique; Sami, Shehzad; Daher, Iyad N.

2011-01-01

402

Pityriasis rosea – a virus-induced skin disease? An update  

Microsoft Academic Search

Summary.  ?Pityriasis rosea (PR) is an acute, inflammatory skin disease of unknown cause. Clinical and experimental findings indicate\\u000a an infectious etiology of PR. Various infectious agents including viruses have been proposed as causative agents and their\\u000a presence in PR samples has been extensively investigated. Recently, human herpesvirus 7 was linked to PR, but contradictory\\u000a findings have been reported by various investigators.

W. Kempf; G. Burg

2000-01-01

403

[The mechanism of laser induced damage to film by metal impurity particle].  

PubMed

The film can be easily damaged by impurity particles, and the damage characteristics of HfO2 film produced by metal particles and the corresponding thermodynamic process were studied. The strong absorption of laser light by metal particles can make film melt, gasified and ionized, and by this way, the film can be peeled and form tround pits point; The metal particle size is closely related to the processes of laser absorption, thermal diffusivity and thermal expansion closely related effects, etc. Under the same irritation energy, the temperature rise is determined by particle size, which can make different size of film damage pits. There is a certain size of metal particle which cause the highest temperature rise and make the film damage easily. Based on the analysis of irradiation ionization effects of laser plasma emission spectrum of the metal particles, the radiation spectrum is mainly focused on the ultraviolet part and photon energy is higher than the incident laser, which has stronger ionization effects, exacerbating the film removal. PMID:23586247

Zhang, Qiu-Hui; Feng, Guo-Ying; Li, Na; Han, Jing-Hua

2013-01-01

404

Erosion induced controllable release of gliclazide encapsulated inside degradable polymeric particles.  

PubMed

The microphase inversion of water-insoluble poly(L-lactide), "poly[(L-lactide)-co-glycolide] and polylactide-block-poly(ethylene oxide)-block-polylactide from THF to water can result in narrowly distributed stable particles. Gliclazide, a commercial drug, can be encapsulated inside during the process. The formation and degradation of such particles was studied by laser light scattering. In comparison with the corrosion of a bulk material, the degradation of each particle is so fast that we only detect the decrease of the particle number, not the corrosion of individual particles. Therefore, the degradation is a "one-by-one" random process, just like the chemical reaction of molecules in solution. The disappearing rate of the particle number is nearly independent of time, ideal for the controlled release of drugs encapsulated inside. The amount of encapsulated gliclazide depends on the copolymer's hydrophobicity (composition), while the releasing rate mainly is, directly related to the disappearing rate of the particles. The correlation between the fluorescence intensity and the degradation was used to study the kinetics of gliclazide releasing. The releasing pattern is controllable with a proper choice of the drug loading, copolymer composition, pH and temperature. PMID:15468221

Zhao, Yue; Chen, Wenna; Cai, Qing; Wang, Shenguo; Bo, Jun; Wu, Chi

2004-03-15

405

Particles shed from syringe filters and their effects on agitation-induced protein aggregation.  

PubMed

We tested the hypothesis that foreign particles shed from filters can accelerate the rate of protein aggregation and particle formation during agitation stress. Various types and brands of syringe filters were tested. Particle counts and size distribution (?1 µm) in buffer alone or in solutions of keratinocyte growth factor 2 (KGF-2) were determined with a micro-flow imaging. Submicron particle populations were characterized by dynamic light scattering. Loss of soluble protein during filtration or postfiltration incubation was determined by ultraviolet spectroscopy and bicinchoninic acid protein assay. There was a wide range (from essentially none to >100,000/mL) in the counts for at least 1 µm particles shed into buffer or KGF-2 solution from the different syringe filters (with or without borosilicate glass microfibers). Filtration of KGF-2 with units containing glass microfibers above the membrane resulted in 20%-80% loss of protein due to adsorption to filter components. Filtration with systems containing a membrane alone resulted in 0%-20% loss of KGF-2. Effects of 24-h postfiltration incubation were tested on KGF-2 solution filtered with polyether sulfone membrane filters. Loss of soluble protein and formation of particles during agitation were much greater than that in control, unfiltered KGF-2 solutions. Similar acceleration of protein aggregation and particle formation was observed when unfiltered KGF-2 solution was mixed with filtered buffer and agitated. Particle shedding from syringe filters--and the resulting acceleration of protein aggregation during agitation--varied greatly among the different syringe filters and individual units of a given filter type. Our results demonstrate that nanoparticles and microparticles shed from the filters can accelerate protein aggregation and particle formation, especially during agitation. PMID:22674153

Liu, Lu; Randolph, Theodore W; Carpenter, John F

2012-06-06

406

High-density lipoprotein subclass and particle size in coronary heart disease patients with or without diabetes  

PubMed Central

Background A higher prevalence of coronary heart disease (CHD) in people with diabetes. We investigated the high-density lipoprotein (HDL) subclass profiles and alterations of particle size in CHD patients with diabetes or without diabetes. Methods Plasma HDL subclasses were quantified in CHD by 1-dimensional gel electrophoresis coupled with immunodetection. Results Although the particle size of HDL tend to small, the mean levels of low density lipoprotein cholesterol(LDL-C) and total cholesterol (TC) have achieved normal or desirable for CHD patients with or without diabetes who administered statins therapy. Fasting plasma glucose (FPG), triglyceride (TG), TC, LDL-C concentrations, and HDL3 (HDL3b and 3a) contents along with Gensini Score were significantly higher; but those of HDL-C, HDL2b+pre?2, and HDL2a were significantly lower in CHD patients with diabetes versus CHD patients without diabetes; The pre?1-HDL contents did not differ significantly between these groups. Multivariate regression analysis revealed that Gensini Score was significantly and independently predicted by HDL2a, and HDL2b+pre?2. Conclusions The abnormality of HDL subpopulations distribution and particle size may contribute to CHD risk in diabetes patients. The HDL subclasses distribution may help in severity of coronary artery and risk stratification, especially in CHD patients with therapeutic LDL, TG and HDL levels.

2012-01-01

407

Surface-enhanced Raman scattering inducible by recyclable Ag-coated magnetic particles  

Microsoft Academic Search

A novel fabrication of Ag-deposited silica-coated Fe3O4 particles and their application as surface-enhanced Raman scattering (SERS) substrates in chemical analyses are demonstrated. Initially, 426-nm sized spherical magnetite particles composed of 13-nm-sized superparamagnetic Fe3O4 nanoparticles were synthesized, and silver coating was conducted using butylamine as the reductant of AgNO3 in ethanol, after direct silica coating on the Fe3O4 particles. The Ag-deposited

Jeong-Yong Choi; Kwan Kim; Kuan Soo Shin

2010-01-01

408

Role of Mutagenicity in Asbestos Fiber-Induced Carcinogenicity and Other Diseases  

PubMed Central

The cellular and molecular mechanisms of how asbestos fibers induce cancers and other diseases are not well understood. Both serpentine and amphibole asbestos fibers have been shown to induce oxidative stress, inflammatory responses, cellular toxicity and tissue injuries, genetic changes, and epigenetic alterations in target cells in vitro and tissues in vivo. Most of these mechanisms are believe to be shared by both fiber-induced cancers and noncancerous diseases. This article summarizes the findings from existing literature with a focus on genetic changes, specifically, mutagenicity of asbestos fibers. Thus far, experimental evidence suggesting the involvement of mutagenesis in asbestos carcinogenicity is more convincing than asbestos-induced fibrotic diseases. The potential contributions of mutagenicity to asbestos-induced diseases, with an emphasis on carcinogenicity, are reviewed from five aspects: (1) whether there is a mutagenic mode of action (MOA) in fiber-induced carcinogenesis; (2) mutagenicity/carcinogenicity at low dose; (3) biological activities that contribute to mutagenicity and impact of target tissue/cell type; (4) health endpoints with or without mutagenicity as a key event; and finally, (5) determinant factors of toxicity in mutagenicity. At the end of this review, a consensus statement of what is known, what is believed to be factual but requires confirmation, and existing data gaps, as well as future research needs and directions, is provided.

Huang, Sarah X. L.; Jaurand, Marie-Claude; Kamp, David W.; Whysner, John; Hei, Tom K.

2011-01-01

409

Role of mutagenicity in asbestos fiber-induced carcinogenicity and other diseases.  

PubMed

The cellular and molecular mechanisms of how asbestos fibers induce cancers and other diseases are not well understood. Both serpentine and amphibole asbestos fibers have been shown to induce oxidative stress, inflammatory responses, cellular toxicity and tissue injuries, genetic changes, and epi