CHO cell engineering to prevent polypeptide aggregation and improve therapeutic protein secretion.

The ability to efficiently produce recombinant proteins in a secreted form is highly desirable and cultured mammalian cells such as CHO cells have become the preferred host as they secrete proteins with human-like post-translational modifications. However, attempts to express high levels of particular proteins in CHO cells may consistently result in low yields, even for non-engineered proteins such as immunoglobulins. In this study, we identified the responsible faulty step at the stage of translational arrest, translocation and early processing for such a "difficult-to-express" immunoglobulin, resulting in improper cleavage of the light chain and its precipitation in an insoluble cellular fraction unable to contribute to immunoglobulin assembly. We further show that proper processing and secretion were restored by over-expressing human signal receptor protein SRP14 and other components of the secretion pathway. This allowed the expression of the difficult-to-express protein to high yields, and it also increased the production of an easy-to-express protein. Our results demonstrate that components of the secretory and processing pathways can be limiting, and that engineering of the secretory pathway may be used to improve the secretion efficiency of therapeutic proteins from CHO cells.

Smart instrumentation for determination of ligament stiffness and ligament balance in total knee arthroplasty.

Ligament balance is an important and subjective task performed during total knee arthroplasty (TKA) procedure. For this reason, it is desirable to develop instruments to quantitatively assess the soft-tissue balance since excessive imbalance can accelerate prosthesis wear and lead to early surgical revision. The instrumented distractor proposed in this study can assist surgeons on performing ligament balance by measuring the distraction gap and applied load. Also the device allows the determination of the ligament stiffness which can contribute a better understanding of the intrinsic mechanical behavior of the knee joint. Instrumentation of the device involved the use of hall-sensors for measuring the distractor displacement and strain gauges to transduce the force. The sensors were calibrated and tested to demonstrate their suitability for surgical use. Results show the distraction gap can be measured reliably with 0.1mm accuracy and the distractive loads could be assessed with an accuracy in the range of 4N. These characteristics are consistent with those have been proposed, in this work, for a device that could assist on performing ligament balance while permitting surgeons evaluation based on his experience. Preliminary results from in vitro tests were in accordance with expected stiffness values for medial collateral ligament (MCL) and lateral collateral ligament (LCL).

In vitro characterization of immune-related properties of human fetal bone cells for potential tissue engineering applications.

We describe herein some immunological properties of human fetal bone cells recently tested for bone tissue-engineering applications. Adult mesenchymal stem cells (MSCs) and osteoblasts were included in the study for comparison. Surface markers involved in bone metabolism and immune recognition were analyzed using flow cytometry before and after differentiation or treatment with cytokines. Immunomodulatory properties were studied on activated peripheral blood mononuclear cells (PBMCs). The immuno-profile of fetal bone cells was further investigated at the gene expression level. Fetal bone cells and adult MSCs were positive for Stro-1, alkaline phosphatase, CD10, CD44, CD54, and beta2-microglobulin, but human leukocyte antigen (HLA)-I and CD80 were less present than on adult osteoblasts. All cells were negative for HLA-II. Treatment with recombinant human interferon gamma increased the presence of HLA-I in adult cells much more than in fetal cells. In the presence of activated PBMCs, fetal cells had antiproliferative effects, although with patterns not always comparable with those of adult MSCs and osteoblasts. Because of the immunological profile, and with their more-differentiated phenotype than of stem cells, fetal bone cells present an interesting potential for allogeneic cell source in tissue-engineering applications.

Engineering Study for the Evaluation of Public Road Administration and Maintenance Alternatives, Executive Summary for HR-265, 1985

Iowa's public road system of 112,000 miles is one of the largest and the best in the nation. It represents a considerable financial investment of taxpayer revenues over the years. And, it requires a sustained investment to preserve an economical level of transport service into the future. In 1982, a Governor's Blue Ribbon Transportation Task Force evaluated the effectiveness of Iowa's entire transportation system. Four important Task Force recommendations dealt with public road administrative issues in Iowa. These issues were related to: 1. design criteria and levels of maintenance 2. consistency in the use of standards among jurisdictions 3. consolidation of maintenance operations at one jurisdictional level and 4. jurisdictional authority for roads. The issues formed the background for Research Project HR-265.

Field Evaluation of Engineering Fabrics for Asphalt Concrete Resurfacing - Audubon County, HR-360, Construction Report, 1994

An asphalt concrete (ACC) overlay is most often the rehabilitative effort used to maintain the serviceability of either an ACC or PCC pavement. The major problem in durability of this ACC overlay comes from reflective cracking. These cracks usually open, allowing water to enter the unsealed crack and strip the ACC in the overlay. The stripping of the ACC allows accelerated deterioration at the crack. Two engineering fabrics were evaluated in this project in order to determine their effectiveness in reducing reflective cracking. These two materials are: PavePrep, Contech Construction Products, Inc., and Pro-Guard, Phillips Fiber Corporation. A 4.2 km (2.6 mi) roadway in Audubon County was selected for the research project. The roadway was divided into eight test sections. Four of the test sections are conventional resurfacing. The other four sections are split between the two engineering fabrics (two Pro-Guard and two PavePrep). A 75 mm (3 in.) thick overlay was placed over the entire project.

Engineering Fabric Repair Prior to Resurfacing - Roadglas - US 30, HR-525, 1992

In Iowa it is normal procedure to either use partial or full-depth patching to repair deteriorated areas of pavement prior to resurfacing. The Owens/Corning Corporation introduced a repair system to replace the patching process. Their Roadglas repair system was used in this research project on US 30 in Story County. It was installed in 1985 and has been observed annually since that time. There were some construction problems with slippage as the roller crossed the abundant Roadglas binder. It appears the Roadglas system has helped to control reflective cracking in the research areas. Since the time when this project was completed it has been reported that Owens/Corning has discontinued production of the Roadglas system.

Crystal engineering studies: polymorphs and co-crystals

We review the key topics of one of the areas with the biggest impact of the last years in the chemical and pharmaceutical industry that is Crystal Engineering. The relevance of polymorphs and co-crystals from different points of view is been highlighted and broadly illustrated by means of several recent examples of studies carried out in this field. In addition, the most suitableinstrumental techniques and the intellectual property implications are reviewed.

Pilot Project for a Hybrid Road-Flooding Forecasting System on Squaw Creek, TR-642

A network of 25 sonic stage sensors were deployed in the Squaw Creek basin upstream from Ames Iowa to determine if the state-of-the-art distributed hydrological model CUENCAS can produce reliable information for all road crossings including those that cross small creeks draining basins as small as 1 sq. mile. A hydraulic model was implemented for the major tributaries of the Squaw Creek where IFC sonic instruments were deployed and it was coupled to CUENCAS to validate the predictions made at small tributaries in the basin. This study demonstrates that the predictions made by the hydrological model at internal locations in the basins are as accurate as the predictions made at the outlet of the basin. Final rating curves based on surveyed cross sections were developed for the 22 IFC-bridge sites that are currently operating, and routine forecast is provided at those locations (see IFIS). Rating curves were developed for 60 additional bridge locations in the basin, however, we do not use those rating curves for routine forecast because the lack of accuracy of LiDAR derived cross sections is not optimal. The results of our work form the basis for two papers that have been submitted for publication to the Journal of Hydrological Engineering. Peer review of our work will gives a strong footing to our ability to expand our results from the pilot Squaw Creek basin to all basins in Iowa.

WISE: Women in Science and Engineering, Fall 2006

Women in Science and Engineering (WISE) Program is to expand and improve educational and professional opportunities for women in all fields of science, technology, engineering and math (STEM) by facilitating individual, institutional, and social change.

WISE: Women in Science and Engineering, Spring 2007

Women in Science and Engineering (WISE) Program is to expand and improve educational and professional opportunities for women in all fields of science, technology, engineering and math (STEM) by facilitating individual, institutional, and social change.

WISE: Women in Science and Engineering, Spring 2009

Women in Science and Engineering (WISE) Program is to expand and improve educational and professional opportunities for women in all fields of science, technology, engineering and math (STEM) by facilitating individual, institutional, and social change.