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- Title
- TWO PROBLEMS ON CROSSING NUMBERS
- Creator
- Wang, Lujia
- Date
- 2013-05-01, 2013-05
- Description
-
The crossing number of a graph G, cr(G) is the minimum number of intersections among edges over all possible drawings on a plane. The pairwise...
Show moreThe crossing number of a graph G, cr(G) is the minimum number of intersections among edges over all possible drawings on a plane. The pairwise crossing number pcr(G) is the the minimum number of pairs of edges that cross at least once over drawings. In the rst part of this survey, we deal with the conjecture that pcr(G) = cr(G), and prove that this is true for 4-edge weighted maps on the annulus. Moreover, we develop methods for solving analogous n-edge problems including the classi cation of permutations on a circle. In the second part, we de ne the generalized crossing number cri(G) as the crossing number of a graph on the orientable surface of genus i. The crossing sequence is de ned as (cri(G))g(G) i=0 , where g(G) is the genus of the graph. This part aims at the conjecture that for each sequence of four numbers decreasing to 0, there is some graph with such numbers as its crossing sequence. We come up with a particular family of graphs which have concave crossing sequences of length 4, but partially prove it.
M.S. in Applied Mathematics, May 2013
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- Title
- Learning Company, Literacy Center, Johannesburg, South Africa: learning co. aisling gray
- Creator
- Gray, Aisling
- Date
- 2010-07-29
- Title
- LICENSE PLATE RECOGNITION SYSTEM USING K NEAREST NEIGHBOR ALGORITHM
- Creator
- Xia, Yong
- Date
- 2012-12-03, 2012-12
- Description
-
License Plate Recognition (LPR) is an image-processing technology, also known as Automatic Number Plate Recognition (ANPR). This technology is...
Show moreLicense Plate Recognition (LPR) is an image-processing technology, also known as Automatic Number Plate Recognition (ANPR). This technology is very popular in fighting crime, locating stolen car, identifying parking-ticket and so on. In LPR system, the image is taken of the front or rear of the car and its quality needs to be enhanced for further process. With this enhanced image, first license plate region is located and extracted. Then character segmentation is performed on extracted license plate image. In this thesis, we use K Nearest Neighbor (KNN) algorithm to recognize these segmented characters. Keywords: LPR, Plate location, character segmentation, Image Processing, KNN
M.S.in Electrical Engineering, December 2012
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- Title
- THERMAL PROCESSING TO MITIGATE ARSENIC CONTENT IN NORTH AMERICAN RICE: TOTAL, SPECIATED ARSENIC AND NUTRIENT EVALUATION
- Creator
- Zhao, Pengyi
- Date
- 2015, 2015-05
- Description
-
Arsenic in the food supply has been a concern since public news reports in 2011 of the detection of arsenic in apple juice. Food and Drug...
Show moreArsenic in the food supply has been a concern since public news reports in 2011 of the detection of arsenic in apple juice. Food and Drug Administration (FDA) work on this issue has proposed a guidance for no more than 10 ppb of inorganic arsenic in apple juice. More recently rice harvested from the southern states of the United States is of concern of the arsenic content. Arsenic levels in rice have been attributed to the natural levels of arsenic in the soil and the farming practices used to grow rice. FDA released data that showed inorganic arsenic amounts in long grain white rice between 70 and 150 ppb. This work presents a process through washing/ rinsing to reduce the arsenic levels in prepared/cooked rice. Four different rice materials were obtained from Mississippi, Arkansas, Texas and Louisiana. Different processing methods such as common cooking, washing and cooking, excess water cooking, were used to prepare the rice. The common cooking method cooked the rice in a 2:1 (water : rice) ratio. The washing and cooking method rinsed a batch of rice with a 2:1 (water : rice) ratio at first, and then poured off wash water and added new water to cook rice in a 2:1 (water : rice) ratio. The excess water cooking method cooked the rice in excess water of a ratio of 4:1 (water : rice) and the excess water was removed after cooking. Controls of raw rice samples were also evaluated. The common cooked rice showed variable to no difference (-13.9% to 14.9%) from the raw control in arsenic retention. The washed and cooked rice showed a 9.8% to 36.8% reduction of arsenic from the control. The excess water cooked rice showed the greatest reduction of arsenic from 39.1% to 65.5% compared to the control. The species of arsenic mimic the total arsenic loss. There is a visible trend for reduction of arsenic content by washing, but the most reduction was achieved by cooking rice with an excess volume of water.
M.S. in Food Safety and Technology, May 2015
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- Title
- Development and Application of an Occupational Odor Hazard Index
- Creator
- Wang, Tingting
- Date
- 2011-04-24, 2011-05
- Description
-
Odors emitted from wastewater treatment and sludge processing facilities may lead to employee complaints regarding discomfort, stress or...
Show moreOdors emitted from wastewater treatment and sludge processing facilities may lead to employee complaints regarding discomfort, stress or disease, and affect productivity and worker turnover in Water Reclamation Plants (WRPs). This study reports and assesses a comprehensive method that estimates the odor perception and associated hazards from exposures to odors in a post-digestion dewatering building in a WRP and its vicinity areas. An Odor Reference Concentration (ORfC) is developed as an index of acceptable odor level. This index is applied to ensure that the majority of building occupants (80 percent or more) do not perceive the odor. This index is developed to fill the lack of a uniform standard and method to assess hazard of exposed individuals to odors in occupational environments and to regulate odor exposures.A comprehensive odor and odorant concentration database was formulated by a monitoring study in the occupational environment of a post-digestion dewatering building. The presence of odorants in the building are at concentrations below occupational exposure limits but higher than odor detection threshold values. This finding indicates that reducing odorant concentrations below exposure limits does not assure an odor-free environment. A model is formulated and validated for this dewatering building associating odor perception with concentrations of total sulfur compounds and relative humidity and is used for prediction of indoor odor concentrations under various conditions. Odor and odorant emission rates as the strength of sources are input variables of the indoor air quality model. In this study, odor and odorant emission rates from freshly dewatered biosolids in a dewatering building were measured using two widely used dynamic methods: the USEPA flux chamber and wind tunnel, and results from the two methods are not significantly different. Comparison of the two methods indicates that both methods can be used to estimate odor and odorant emission rates but the most effective and efficient method depends on prevailing environmental conditions. The ORfC established based on the comprehensive odor and odorant concentration database for this dewatering building is 13D/T (dilution to threshold). This index is used to evaluate seven control strategies recommended to reduce odor levels. If indoor odor concentrations in the occupational environment exceed the ORfC, then the hazard of odor exposures is unacceptable. Deterministic results of this study indicate that if appropriate control strategy is applied, odor concentration in the dewatering building would reach to below levels that cause unnecessary stress and other effects. The control strategy focus of this work is reduction of the indoor odor perception. But indoor control strategies must not cause outdoor odor problems to surrounding residential areas. Therefore, the potential impact of the control strategy recommended is also investigated in this thesis using the US EPA recommended air dispersion modeling AERMOD. Predictions of hydrogen sulfide concentrations at surrounding areas of the plant indicate that only one strategy, which proposes to add a new exhaust system in the dewatering building, would cause the ambient hydrogen sulfide concentration to be 7% higher than the odor detection threshold; other six strategies would not induce odor annoyance to surrounding areas. Acute and long-term ambient hydrogen sulfide exposure limits based on human health and irritation effects would not be violated under any of the seven control strategies.
Ph.D. in Environmental Engineering, May 2011
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- Title
- The titration of iron by potassium permanganate
- Creator
- Finkelstein, Leo
- Date
- 2009, 1914
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/titrationofironb00fink
Thesis (B.S.)--Armour Institute of Technology
- Title
- Church & School Energy Efficiency and Financing Program (sequence unknown), IPRO 328 - Deliverables: IPRO 328 Final Report F09_redacted
- Creator
- Ciuffini, Kathryn, Kim, Ja Young, Knapczyk, Robert, Mckinley, Matthew, O'brien, Patrick, Maddamma, Todd, Schafer, Michael, Soderling, Philip, Wedster, Bonnie
- Date
- 2009-12
- Description
-
The Fall 2009 IPRO 328 team envisions the development and ultimately execution of a volunteer program which would facilitate the...
Show moreThe Fall 2009 IPRO 328 team envisions the development and ultimately execution of a volunteer program which would facilitate the implementation of energy saving improvements in a church and/or parochial school within the surrounding neighborhoods of IIT campus.
Sponsorship: Vince Cushing of Clean Urban Energy
Deliverables for IPRO 328: Church & School Energy Efficiency and Financing Program for the fall 2009 semester
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- Title
- APPROACHES TO QUANTIFY AND COMPARE THE THERMAL STABILITY OF FOOD ALLERGENS
- Creator
- Meng Xu
- Date
- 2013-04-24, 2013-05
- Description
-
Stability to heat or other food processing conditions has been suggested as one of the characteristics of food allergens, however there is in...
Show moreStability to heat or other food processing conditions has been suggested as one of the characteristics of food allergens, however there is in general a lack of standardized approach to determine or compare the thermal stabilities of food allergens. This study evaluated the use of several analytical tools including the BCA total protein assay, Far-UV Circular Dichroism Spectroscopy, Differential Scanning Calorimetry, and inhibition ELISA assays to study the changes in the structural and immunological properties of major allergens as a result of heat treatments, and identified parameters that can be used to quantify and compare the thermal stability of food allergens. Purified allergens from milk, egg, and almond were subjected to moist-heat or dry-heat treatments and changes in protein solubility, IC50 values and thermodynamic properties of each protein were determined. It was found that high transition temperature (Tm) was closely related to a greater resistance to changes in immunological properties after heat treatments, suggesting that it can be a good parameter to quantify and compare the thermal stability of different food allergens.
M.S. in Food Safety and Technology, May 2013
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- Title
- Cessation of Screech in Underexpanded Jets
- Creator
- Raman, G.
- Date
- 1997-04-10
- Publisher
- Cambridge Univ Press
- Description
-
In significantly underexpanded jets, screech inherently ceases to exist. This paper studies screech cessation in a supersonic rectangular jet...
Show moreIn significantly underexpanded jets, screech inherently ceases to exist. This paper studies screech cessation in a supersonic rectangular jet and provides an explanation for its occurrence. Experimental data are presented for fully expanded Mach numbers, M-j, ranging from 1.1 to 1.9. Screech becomes unsteady beyond M-j = 1.65 and ceases to exist beyond M-j = 1.75. The reason for this cessation has remained a mystery, and this paper examines three suspects: (i) the theory of a frequency mismatch between screech tones and the band of the most-amplified jet instability waves, (ii) the notion that Mach disk formation disrupts the shock-cell structure and weakens the screech-producing shocks, and (iii) the idea that acoustic feedback and receptivity diminish at high levels of underexpansion. A thorough interrogation of experimental data shows that (i) is not the main cause of screech cessation here, (ii) plays an insignificant role, and (iii) appears to have been largely responsible for screech cessation. Cessation occurs because feedback to the jet lip is diminished due to excessive expansion of the jet boundary. Further, since the jet lip now reflects and scatters low intensity sound, the end result is poor receptivity at the initial shear layer. This theory is substantiated by the re-activation of screech when the nozzle lip thickness is made larger than the expanded jet boundary. Finally, increasing lip thickness is seen to produce a systematic shift (to higher M-j) of the onset of cessation. The results of this study are of direct relevance to the sonic fatigue problem in aircraft structures, because understanding screech helps prevent such damage.
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- Title
- Interactive Urban Landmark Kiosks for Memorial Walk of Martin Luther King (sequence unknown), IPRO 314 - Deliverables: IPRO 314 IPRO Day Presentation F09
- Creator
- O’leary, Kevin, Petty, Sonya, Qi, Tianshu, Tan, Sophia, Noor, Nashrah, Schleich, Kenneth, Akhtar, Ayesha, Cheng, Eric, Kim, James, Parker, Joseph, Saha, Sougata
- Date
- 2009-12
- Description
-
The objective of this IPRO is to help the students of Gage Park H.S. bring their vision of a memorial to a historical event into existence.
Spo...
Show moreThe objective of this IPRO is to help the students of Gage Park H.S. bring their vision of a memorial to a historical event into existence.
Sponsorship: Gage Park High School
Deliverables for IPRO 314: Interactive Urban Landmark Kiosks for Memorial Walk of Martin Luther King for the fall 2009 semester.
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- Title
- INVESTIGATION OF ANION EXCHANGE MEMBRANES FOR ELECTROCHEMICAL ENERGY CONVERSION AND STORAGE SYSTEMS
- Creator
- Wang, Lihui
- Date
- 2017, 2017-05
- Description
-
The alkaline stability of poly (arylene ether) backbones in anion exchange membranes (AEMs) derivatized with quaternary benzyl N, N-...
Show moreThe alkaline stability of poly (arylene ether) backbones in anion exchange membranes (AEMs) derivatized with quaternary benzyl N, N- dimethylhexylammmonium (DMH+) and trimethylammonium (TMA+) cation groups were investigated in poly (2,6- dimethyl 1,4-phenylene) oxide (PPO) and Udel® polysulfone (PSF) polymers. Previous studies have demonstrated that quaternary ammonium and phosphonium groups trigger backbone degradation in commercially available poly (arylene ether)-based AEMs, despite the base polymers’ resilience to alkaline solutions. Herein, I demonstrate that the electron withdrawing or donating character in the poly (arylene ether) backbone ultimately dictates whether the prepared AEMs will become brittle in alkaline media due to cation-triggered backbone degradation (Arges, Parrondo, Johnson, Nadhan, & Ramani, 2012a; Christopher G. Arges, Lihui Wang, Javier Parrondo, & Vijay Ramani, 2013). Mitigation of cation-triggered backbone degradation was only achieved when electron withdrawing substituents (not including the cation), such as sulfone or bromine, were eliminated from the polymer backbone (or, alternately, when electron donating groups were present). Hence, PPO AEMs prepared through chloromethylation, rather than free radical bromination, were resistant to backbone hydrolysis in alkaline media because each cation-functionalized repeat unit had two electron-donating methyl groups rather than a single methyl group. This study presents some design rules for preparing mechanically stable poly (arylene ether) AEMs from low cost, commercially available polymers for alkaline electrochemical devices.
Ph.D. in Chemical Engineering, May 2017
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- Title
- NUMERICAL SIMULATIONS OF CURVATURE WEAKENING MODEL OF REACTIVE HELE-SHAW FLOW
- Creator
- Zhao, Meng
- Date
- 2013, 2013-12
- Description
-
In this paper, we study a moving interface problem in a Hele-Shaw cell, where two immiscible reactive fluids meet at the interface and...
Show moreIn this paper, we study a moving interface problem in a Hele-Shaw cell, where two immiscible reactive fluids meet at the interface and initiate chemical reactions. A new gel-like phase is produced at the interface and may modify the elastic bending property there. We model the interface as an elastic membrane with a local curva- ture dependent bending rigidity. In the first part of this paper, we review the linear stability analysis on a curvature weakening model, and derive critical flux conditions such that a Hele-Shaw bubble can develop unstable fingering pattern and self-similar morphology. In the second part of this report, we develop a boundary integral nu- merical algorithm to perform nonlinear simulations. Preliminary numerical results show that in the nonlinear regime, there also exist stable self-similar solutions.
M.S. in Applied Mathematics, December 2013
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- Title
- Study of pp interactions at high multiplicity at U-70, Proceedings of the XLIII International Symposium on Multiparticle Dynamics
- Creator
- Aleev, A., Avdeichikov, V., Balandin, V., Borzunov, Yu., Chencov, Yu., Dunin, V., Furmanec, N., Kekelidze, G., Kireev, V., Kokoulina, E., Ladygin, V., Myalkovsky, V., Nikitin, V., Peshehonov, V., Petukhov, Yu., Rufanov, I., Yukaev, A., Zhidkov, N., Basiladze, S., Bogdanova, G., Erofeeva, I., Grishin, N., Grishkevich, Ya., Karmanov, D., Kramarenko, V., Leflat, A., Merkin, M., Popov, V., Tihonova, L., Vishnevskaya, A., Volkov, V., Voronin, A., Zverev, E., Ardashev, E., Afonin, A., Golovkin, V., Golovnya, S., Gorokhov, S., Kholodenko, A., Kiryakov, A., Kurchaniniv, L., Lobanov, I., Lobanova, E., Mitrofanov, G., Petrov, V., Pleskach, A., Polkovnikov, M., Ronzhin, V., Ryadovikov, V., Senko, V., Soldatov, M., Shalanda, N., Tsyupa, Yu., Vorobiev, A., Yakimchuk, V., Zapolsky, V., Kutov, A.
- Date
- 2013-09-15, 2013-09-15
- Publisher
- IIT Press
- Description
-
The E190 Experiment is aimed at the search for collective phenomena in a quark-gluon system and a hadron system. It is carried out at U-70 in...
Show moreThe E190 Experiment is aimed at the search for collective phenomena in a quark-gluon system and a hadron system. It is carried out at U-70 in IHEP, Protvino. The evidence of Bose-Einstein condensation of pions has been confirmed with a twofold increasing of sampling at a level of 7 standard deviations. We study soft photon (smaller than 60 MeV) yield by using of an electromagnetic calorimeter with low energy threshold. In the gluon dominance model we explain multiparticle production by the active gluons. In this model the estimation of the contribution of charge exchange has been obtained.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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- Title
- Power Measurement for Road Bicycles: Towards a Universal Solution (sequence unknown), IPRO 324 - Deliverables: IPRO 324 Project Plan F09_redacted
- Creator
- Adrianzen, Luis, Allen, Ross, Antonio, Chris, Callan, Mark, Claxton, Sara, Diesse, Patrick, Gaylord, Matthew, Herbert, Greg, Shaffer, Dan, Wegrzyn, Celeste
- Date
- 2009-12
- Description
-
The goal of the IPRO is to try to find an inexpensive, but accurate way of measuring the power output of a rider on a bicycle. Problems with...
Show moreThe goal of the IPRO is to try to find an inexpensive, but accurate way of measuring the power output of a rider on a bicycle. Problems with systems currently available are: some products are not compatible with all bike systems causing the need to purchase new parts, the cost of the available products is expensive, and some of the available measuring systems are not very accurate.
Deliverables for IPRO 324: Power Measurement for Road Bicycles: Towards a Universal Solution for the fall 2009 semester
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- Title
- HACCP with multivariate process monitoring and fault diagnosis techniques: application to a food pasteurization process
- Creator
- Tokatli, F., Cinar, A., Schlesser, J. E.
- Date
- 2005-06
- Publisher
- ELSEVIER SCI LTD
- Description
-
Multivariate statistical process monitoring (SPM), and fault detection and diagnosis (FDD) methods are developed to monitor the critical...
Show moreMultivariate statistical process monitoring (SPM), and fault detection and diagnosis (FDD) methods are developed to monitor the critical control points (CCPs) in a continuous food pasteurization process. Multivariate SPM techniques effectively use information from all process variables to detect abnormal process behavior. Fault diagnosis techniques isolate the source cause of the deviation in process variable(s). The methods developed are illustrated by implementing them to monitor the critical control points and diagnose causes of abnormal operation of a high temperature short time (HTST) pasteurization pilot plant. The detection power of multivariate SPM and FDD techniques over univariate SPM techniques is shown and their integrated use to ensure the product safety and quality in food processes is demonstrated.
Endnote format citation for DOI:10.1016/j.foodcont.2004.04.008
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- Title
- Ozone Delivery System Binder
- Creator
- Cooper, Kerri, Lee, Alvin, Slade, Peter
- Date
- 2010-09-10T18:51:34Z
- Description
-
Development and validation of the Ozone Delivery System
- Title
- Fab Lab: Creating Design-to-Prototype Learning Modules at the Museum of Science and Industry (sequence unknown), IPRO 333 - Deliverables: IPRO 333 Final Report F09
- Creator
- Bonesz, Andrew, Clark, Howard, Douglas, Carlie, Gajdorus, Michael, Gottschall, Keenan, Hendricks, Rachel, Kimball, Clayton, Linares, Jared, Marks, Paul, Mellom, James, Oblenida, Cindy, Pop, Sabina, Stelcel, Carl, Young, Jeremy, Zhou, Raymond
- Date
- 2009-12
- Description
-
The primary objective of IPRO 333 is to partner the knowledge and ideas of young engineers, architects, and scientists at IIT with the...
Show moreThe primary objective of IPRO 333 is to partner the knowledge and ideas of young engineers, architects, and scientists at IIT with the resources of the Museum of Science and Industry (MSI) in Chicago. This partnership endeavors to help the museum's Fabrication Laboratory (Fab Lab) maximize its potential as a resource for museum guests, young and old, as well as for IIT students, staff, and faculty.
Sponsorship: Museum of Science and Industry. Steven Willis- Director, Fabrication Lab
Deliverables for IPRO 333: Fab Lab: Creating Design-to-Prototype Learning Modules at the Museum of Science and Industry for the fall 2009 semester
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- Title
- TRANSFER RATE OF NOROVIRUS DURING CHOPPING ROMAINE LETTUCE
- Creator
- Li, Mingming
- Date
- 2012-11-24, 2012-12
- Description
-
Human noroviruses (HuNoV) are the leading cause of outbreaks of nonbacterial gastroenteritis in the U.S., and are often implicated in...
Show moreHuman noroviruses (HuNoV) are the leading cause of outbreaks of nonbacterial gastroenteritis in the U.S., and are often implicated in outbreaks associated with ready-to-eat foods, such as salads. Such foods may be extensively handled, and norovirus may be transferred readily between infected food handlers and food surfaces. The aim of this study was to investigate norovirus transfer between surfaces and romaine lettuce which were commonly used in the preparation of fresh food. Fresh Romaine lettuce was cut into 25cm2 pieces and inoculated with 25 μl (approx. 7-log PFU) murine norovirus (MNV-1) per leaf. After 10 min air-drying, 5 g piles of inoculated leaves were cut with a sterile stainless steel knife on a sterile cutting board. Sampling sponges soaked in Dulbecco’s Modified Eagle’s Media (DMEM) were used to swab blade and board surfaces for MNV-1 transferred from lettuce. In some cases, fresh, uninoculated Romaine lettuce was chopped using the contaminated knife and board. MNV-1 transferred to the chopped lettuce was recovered by stomaching in DMEM and enumerated by plaque assay. MNV-1 transfer was lower from contaminated lettuce to cutting board (p<0.05) than that from a contaminated cutting board to lettuce. This same trend was observed between a stainless steel knife and lettuce. The MNV-1 transfer coefficient was lower when contaminated lettuce was chopped on a wood board (p<0.05) compared to a polyvinyl cutting board. Norovirus transfers readily between surfaces common in the preparation of fresh produce preparation, but the transfer coefficient appears to be dependent on the surface type. This research provides the scientific basis for the development of a risk assessment model for norovirus transfer during the fresh food preparation.
M.S. in Food Safety and Technology, December 2012
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- Title
- MODELING OF A DCFC ANODE IN CONNECTION WITH THE EXPERIMENTAL RESEARCH ON THE WETTING BEHAVIOR OF A GRAPHIC ROD IN MOLTEN CARBONATE
- Creator
- Li, Yue
- Date
- 2013, 2013-12
- Description
-
Not available
M.S. in Civil Engineering, July 2013
- Title
- THE EFFECT OF FLOW ON MICROPARTICLE TRANSPORT AND THE ROLE OF MICROPARTICLES IN THROMBOSIS
- Creator
- Lee, Ying-hui
- Date
- 2012-11-27, 2012-12
- Description
-
Elevated monocyte/macrophage-derived microparticles (MPs) have been found to correlate with thrombotic complications. These MPs carry tissue...
Show moreElevated monocyte/macrophage-derived microparticles (MPs) have been found to correlate with thrombotic complications. These MPs carry tissue factor (TF), the principal coagulation pathway initiator, as their parental cells and expose anionic phospholipid phosphatidylserine (PS), which can promote thrombin generation and fibrin formation. During thrombus development, MPs may be delivered to the injured/dysfunctional vascular endothelium or biomaterial surfaces and influence the process of thrombosis. MPs are submicron membrane vesicles that may have increased transport and/or binding capabilities compared to platelets or other cell types due to their decreased size and their higher Brownian diffusion. MPs and their surface molecules can be delivered to surfaces, either biological or prosthetic, and alter the local environment. Little is known of the mechanisms by which MPs are transported to and impart their biological activity on surfaces, especially in blood. Such a transfer of activity will depend on the ability of MPs to be transported to the surface, the strength of adhesion of the MPs on the surface and the nature of the activity/host interaction. In the present study, physical and biological properties of MPs generated from macrophage-like cell lines by endotoxin stimulation were characterized, the transport of MPs to surface by flow was investigated, and the import biological activity on surfaces was elucidated. We observed that the deposition of MPs suspended in buffer on glass surfaces was strongly shear-dependent using a well-defined parallel plate flow chamber. The diffusivity coefficients of MPs at shear rate ranges ranging from 100 to 3200 s-1 were determined from the classical mass transport equation proposed by Leveque and the values were found to be of the same order of magnitude as predicted by Brownian xi diffusion. MPs non-specific attachment to glass was dominated by electrostatic interactions; this was verified by changing the surrounding ionic strength of the suspending solution. In addition to shear rate, red blood cells (RBCs) also influenced MP adhesion due to the complex movement of RBCs. Such movement has been shown to enhance the adhesion of platelets (1-2 micron size cells) to surfaces in flowing blood. MP lateral transport was enhanced at low concentrations of RBCs and reduced at higher concentration of RBCs. The reduction of MP deposition was due to the competition for surface binding sites between the two populations of MPs. The two types of MPs studied here, those produced by macrophages after endotoxin stimulation and those produced by RBCs during experimental preparation (repeated centrifugal washing) have the capability of nonspecific binding to artificial surfaces in a competitive manner. Finally, we demonstrated that the amount of adherent MPs on surfaces influenced fibrin formation via both a TF-dependent and a negatively charged phospholipid pathway. These findings suggest that procoagulant MPs may modulate thrombotic events under certain conditions, especially in MP-associated diseases. The knowledge of the effects of flow on MP transport and the influence of increased MPs on thrombosis may provide novel insights for the transfer of biological activity to relatively passive surfaces.
PH.D in in Biomedical Engineering, December 2012
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