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Full-Text Articles in Physical Sciences and Mathematics

Nanoroughened Surfaces For Efficient Capture Of Circulating Tumor Cells Without Using Capture Antibodies, Weiqiang Chen, Shinuo Weng, Feng Zhang, Steven Allen, Xiang Li, Liwei Bao, Raymond H. W. Lam, Jill A. Macoska, Sofia D. Merajver, Jianping Fu Nov 2012

Nanoroughened Surfaces For Efficient Capture Of Circulating Tumor Cells Without Using Capture Antibodies, Weiqiang Chen, Shinuo Weng, Feng Zhang, Steven Allen, Xiang Li, Liwei Bao, Raymond H. W. Lam, Jill A. Macoska, Sofia D. Merajver, Jianping Fu

Weiqiang Chen

Circulating tumor cells (CTCs) detached from both primary and metastatic lesions represent a potential alternative to invasive biopsies as a source of tumor tissue for the detection, characterization and monitoring of cancers. Here we report a simple yet effective strategy for capturing CTCs without using capture antibodies. Our method uniquely utilized the differential adhesion preference of cancer cells to nanorough surfaces when compared to normal blood cells and thus did not depend on their physical size or surface protein expression, a significant advantage as compared to other existing CTC capture techniques.


Cosmic Ray Particles Images With Orca-Ii Erg, George Mcnamara Aug 2012

Cosmic Ray Particles Images With Orca-Ii Erg, George Mcnamara

George McNamara

Cosmic ray particles image series acquired using a Hamamatsu ORCA-II ERG scientific grade CCD camera, cooled to -60 C. Each image is a consecutive 600 second (10 minute) exposure time with no light to the camera.

While processing the data, I discoverd that the background changed around planes 25 and 227 (see Excel file and jpeg screenshots), so I also processed only planes 025-227 (203 planes total, 2030 minutes, 33.83 hours). the CCD industry "rule of thumb" for a "typical" CCD sensor (i.e. 1/3" CCD) is that one cosmic ray particle strikes a sensor approximately every 30 seconds (assuming not …


Environmental Impacts Of Stover Removal In The Corn Belt, Alicia English, Wallace E. Tyner, Juan Sesmero, Phillip Owens, David J. Muth Jr. Aug 2012

Environmental Impacts Of Stover Removal In The Corn Belt, Alicia English, Wallace E. Tyner, Juan Sesmero, Phillip Owens, David J. Muth Jr.

David J. Muth

When considering the market for biomass from corn stover resources erosion and soil quality issues are important to consider. Removal of stover can be beneficial in some areas, especially when coordinated with other conservation practices, such as vegetative barrier strips and cover crops. However, benefits are highly dependent on several factors, namely if farmers see costs and benefits associated with erosion and the tradeoffs with the removal of biomass. This paper uses results from an integrated RUSLE2/WEPS model to incorporate six different regime choices, covering management, harvest and conservation, into a simple profit maximization model to show these tradeoffs.


Nanotopography Influences Adhesion, Spreading, And Self-Renewal Of Human Embryonic Stem Cells, Weiqiang Chen, Luis G. Villa-Diaz, Yubing Sun, Shinuo Weng, Jin Koo Kim, Raymond H. W. Lam, Lin Han, Rong Fan, Paul H. Krebsbach, Jianping Fu Apr 2012

Nanotopography Influences Adhesion, Spreading, And Self-Renewal Of Human Embryonic Stem Cells, Weiqiang Chen, Luis G. Villa-Diaz, Yubing Sun, Shinuo Weng, Jin Koo Kim, Raymond H. W. Lam, Lin Han, Rong Fan, Paul H. Krebsbach, Jianping Fu

Weiqiang Chen

Human embryonic stem cells (hESCs) have great potentials for future cell-based therapeutics. However, their mechanosensitivity to biophysical signals from the cellular microenvironment is not well characterized. Here we introduced an effective microfabrication strategy for accurate control and patterning of nanoroughness on glass surfaces. Our results demonstrated that nanotopography could provide a potent regulatory signal over different hESC behaviors, including cell morphology, adhesion, proliferation, clonal expansion, and self-renewal. Our results indicated that topological sensing of hESCs might include feedback regulation involving mechanosensory integrin-mediated cell matrix adhesion, myosin II, and E-cadherin. Our results also demonstrated that cellular responses to nanotopography were cell-type …


Integrative Bayesian Analysis Of High-Dimensional Multi-Platform Genomics Data, Wenting Wang, Veerabhadran Baladandayuthapani, Jeffrey S. Morris, Bradley M. Broom, Ganiraju C. Manyam, Kim-Anh Do Jan 2012

Integrative Bayesian Analysis Of High-Dimensional Multi-Platform Genomics Data, Wenting Wang, Veerabhadran Baladandayuthapani, Jeffrey S. Morris, Bradley M. Broom, Ganiraju C. Manyam, Kim-Anh Do

Jeffrey S. Morris

Motivation: Analyzing data from multi-platform genomics experiments combined with patients’ clinical outcomes helps us understand the complex biological processes that characterize a disease, as well as how these processes relate to the development of the disease. Current integration approaches that treat the data are limited in that they do not consider the fundamental biological relationships that exist among the data from platforms.

Statistical Model: We propose an integrative Bayesian analysis of genomics data (iBAG) framework for identifying important genes/biomarkers that are associated with clinical outcome. This framework uses a hierarchical modeling technique to combine the data obtained from multiple platforms …


Optimal Switching Control Of A Fed-Batch Fermentation Process, Chongyang Liu, Zhaohua Gong, Enmin Feng, Hongchao Yin Jan 2012

Optimal Switching Control Of A Fed-Batch Fermentation Process, Chongyang Liu, Zhaohua Gong, Enmin Feng, Hongchao Yin

Chongyang Liu

Considering the hybrid nature in fed-batch culture of glycerol biconversion to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae, we propose a state-based switching dynamical system to describe the fermentation process. To maximize the concentration of 1,3-PD at the terminal time, an optimal switching control model subject to our proposed switching system and constraints of continuous state inequality and control function is presented. Because the number of the switchings is not known a priori, we reformulate the above optimal control problem as a two-level optimization problem. An optimization algorithm is developed to seek the optimal solution on the basis of a heuristic approach …


Nonlinear Dynamical Systems Of Fed-Batch Fermentation And Their Optimal Control, Chongyang Liu, Zhaohua Gong, Enmin Feng, Hongchao Yin Jan 2012

Nonlinear Dynamical Systems Of Fed-Batch Fermentation And Their Optimal Control, Chongyang Liu, Zhaohua Gong, Enmin Feng, Hongchao Yin

Chongyang Liu

In this article, we propose a controlled nonlinear dynamical system with variable switching instants, in which the feeding rate of glycerol is regarded as the control function and the moments between the batch and feeding processes as switching instants, to formulate the fed-batch fermentation of glycerol bioconversion to 1,3-propanediol (1,3-PD). Some important properties of the proposed system and its solution are then discussed. Taking the concentration of 1,3-PD at the terminal time as the cost functional, we establish an optimal control model involving the controlled nonlinear dynamical system and subject to continuous state inequality constraints. The existence of the optimal …


Modeling And Parameter Identification Involving 3-Hydroxypropionaldehyde Inhibitory Effects In Glycerol Continuous Fermentation, Zhaohua Gong, Chongyang Liu, Yongsheng Yu Jan 2012

Modeling And Parameter Identification Involving 3-Hydroxypropionaldehyde Inhibitory Effects In Glycerol Continuous Fermentation, Zhaohua Gong, Chongyang Liu, Yongsheng Yu

Chongyang Liu

Mathematical modeling and parameter estimation are critical steps in the optimization of biotechnological processes. In the 1,3-propanediol (1,3-PD )production by glycerol fermentation process under anaerobic conditions, 3-hydroxypropionaldehyde (3-HPA) accumulation would arouse an irreversible cessation of the fermentation process. Considering 3-HPA inhibitions to cells growth and to activities of enzymes, we propose a novel mathematical model to describe glycerol continuous cultures. Some properties of the above model are discussed. On the basis of the concentrations of extracellular substances, a parameter identification model is established to determine the kinetic parameters in the presented system. Through the penalty function technique combined with an …


Optimal Control Of A Fed-Batch Fermentation Involving Multiple Feeds, Chongyang Liu, Zhaohua Gong, Zhaoyi Huo, Bangyu Shen Jan 2012

Optimal Control Of A Fed-Batch Fermentation Involving Multiple Feeds, Chongyang Liu, Zhaohua Gong, Zhaoyi Huo, Bangyu Shen

Chongyang Liu

A nonlinear dynamical system, in which the feed rates of glycerol and alkali are taken as the control functions, is first proposed to formulate the fed-batch culture of 1,3-propanediol (1,3-PD) production. To maximize the 1,3-PD concentration at the terminal time, a constrained optimal control model is then presented. A solution approach is developed to seek the optimal feed rates based on control vector parametrization method and improved differential evolution algorithm. The proposed methodology yielded an increase by 32.17% of 1,3-PD concentration at the terminal time.


Improving Biomass Logistics Cost Within Agronomic Sustainability Constratints And Biomass Quality Targets, Kevin L. Kenney, J. Richard Hess, William A. Smith, David J. Muth Jr. Jan 2012

Improving Biomass Logistics Cost Within Agronomic Sustainability Constratints And Biomass Quality Targets, Kevin L. Kenney, J. Richard Hess, William A. Smith, David J. Muth Jr.

David J. Muth

Equipment manufacturers have made rapid improvements in biomass harvesting and handling equipment. These improvements have increased transportation and handling efficiencies due to higher biomass densities and reduced losses. Improvements in grinder efficiencies and capacity have reduced biomass grinding costs. Biomass collection efficiencies (the ratio of biomass collected to the amount available in the field) as high as 75% for crop residues and greater than 90% for perennial energy crops have also been demonstrated. However, as collection rates increase, the fraction of entrained soil in the biomass increases, and high biomass residue removal rates can violate agronomic sustainability limits. Advancements in …


Economics Of Residue Harvest: Regional Partnership Evaluation, David W. Archer, David J. Muth Jr., Jacob J. Jacobson, Douglas L. Karlen Jan 2012

Economics Of Residue Harvest: Regional Partnership Evaluation, David W. Archer, David J. Muth Jr., Jacob J. Jacobson, Douglas L. Karlen

David J. Muth

Economic analyses on the viability of corn (Zea mays, L.) stover harvest for bioenergy production have largely been based on simulation modeling. While some studies have utilized field research data, most field-based analyses have included a limited number of sites and a narrow geographic distribution. An Iowa case study is developed illustrating the use of data extracted from a database of geographically distributed field studies for a region-specific economic analysis. The analysis utilizes grain and residue yield and associated management information from two Iowa field research sites that are Sun Grant Regional Partnership locations associated with the Corn Stover Regional …


Economics Of Residue Harvest: Regional Partnership Evaluation, David W. Archer, David J. Muth Jr., Jacob J. Jacobson, Douglas L. Karlen Dec 2011

Economics Of Residue Harvest: Regional Partnership Evaluation, David W. Archer, David J. Muth Jr., Jacob J. Jacobson, Douglas L. Karlen

Douglas L Karlen

Economic analyses on the viability of corn (Zea mays, L.) stover harvest for bioenergy production have largely been based on simulation modeling. While some studies have utilized field research data, most field-based analyses have included a limited number of sites and a narrow geographic distribution. An Iowa case study is developed illustrating the use of data extracted from a database of geographically distributed field studies for a region-specific economic analysis. The analysis utilizes grain and residue yield and associated management information from two Iowa field research sites that are Sun Grant Regional Partnership locations associated with the Corn Stover Regional …