Illinois Institute of Technology

About: Illinois Institute of Technology is a education organization based out in Chicago, Illinois, United States. It is known for research contribution in the topics: Electric power system & Wireless network. The organization has 10188 authors who have published 21062 publications receiving 554178 citations. The organization is also known as: IIT & Illinois Tech.

Effects of Ru on the high-temperature phase stability of Ni-base single-crystal superalloys

Abstract: Microstructural instabilities associated with the precipitation of refractory-rich topologically-close-packed (TCP) phases within the microstructure of advanced Ni-base single-crystal superalloys were quantified in two nominally identical alloys with and without additions of Ru. Differences in the microstructural kinetics associated with the formation of TCP precipitates in these experimental single-crystal superalloys enabled the influence of Ru to be assessed. Detailed microstructural investigations were carried out on specimens subjected to prolonged isothermal exposures at elevated temperature. Even after 1000 hours at temperatures in excess of 1100 °C, the microstructure of the Ru-bearing alloy was highly resistant to the formation of TCP phases. Transmission electron micro-analysis (TEM) coupled with X-ray diffraction (XRD) was used to identify the characteristic crystal structures of the TCP precipitates in both alloys as being primarily the orthorhombic P and tetragonal σ phase. The sluggish precipitation kinetics of TCP phases in the Ru-bearing single-crystal Ni-base superalloy prevents the breakdown of the parent γ-γ′ microstructure and greatly enhances the high-temperature creep characteristics.

Titin isoform variance and length dependence of activation in skinned bovine cardiac muscle.

Abstract: We have explored the role of the giant elastic protein titin in the Frank-Starling mechanism of the heart by measuring the sarcomere length (SL) dependence of activation in skinned cardiac muscles with different titin-based passive stiffness characteristics. We studied muscle from the bovine left ventricle (BLV), which expresses a high level of a stiff titin isoform, and muscle from the bovine left atrium (BLA), which expresses more compliant titin isoforms. Passive tension was also varied in each muscle type by manipulating the pre-history of stretch prior to activation. We found that the SL-dependent increases in Ca2+ sensitivity and maximal Ca2+-activated tension were markedly more pronounced when titin-based passive tension was high. Small-angle X-ray diffraction experiments revealed that the SL dependence of reduction of interfilament lattice spacing is greater in BLV than in BLA and that the lattice spacing is coupled with titin-based passive tension. These results support the notion that titin-based passive tension promotes actomyosin interaction by reducing the lattice spacing. This work indicates that titin may be a factor involved in the Frank-Starling mechanism of the heart by promoting actomyosin interaction in response to stretch.

Effect of grape seed extract on blood pressure in subjects with the metabolic syndrome.

Abstract: This study was undertaken to determine whether grape seed extracts (GSE) that contain powerful vasodilator phenolic compounds lower blood pressure in subjects with the metabolic syndrome. The subjects were randomized into 3 groups—(a) placebo, (b) 150 mg GSE per day, and (c) 300 mg GSE per day—and treated for 4 weeks. Serum lipids and blood glucose were measured at the beginning of the study and at the end. Blood pressure was recorded using an ambulatory monitoring device at the start of the treatment period and at the end. Both the systolic and diastolic blood pressures were lowered after treatment with GSE as compared with placebo. There were no significant changes in serum lipids or blood glucose values. These findings suggest that GSE could be used as a nutraceutical in a lifestyle modification program for patients with the metabolic syndrome.

Use of Genetically Engineered Microorganisms (GEMs) for the Bioremediation of Contaminants

Abstract: This paper presents a critical review of the literature on the application of genetically engineered microorganisms (GEMs) in bioremediation. The important aspects of using GEMs in bioremediation, such as development of novel strains with desirable properties through pathway construction and the modification of enzyme specificity and affinity, are discussed in detail. Particular attention is given to the genetic engineering of bacteria using bacterial hemoglobin (VHb) for the treatment of aromatic organic compounds under hypoxic conditions. The application of VHb technology may advance treatment of contaminated sites, where oxygen availability limits the growth of aerobic bioremediating bacteria, as well as the functioning of oxygenases required for mineralization of many organic pollutants. Despite the many advantages of GEMs, there are still concerns that their introduction into polluted sites to enhance bioremediation may have adverse environmental effects, such as gene transfer. The extent of horizontal gene transfer from GEMs in the environment, compared to that of native organisms including benefits regarding bacterial bioremediation that may occur as a result of such transfer, is discussed. Recent advances in tracking methods and containment strategies for GEMs, including several biological systems that have been developed to detect the fate of GEMs in the environment, are also summarized in this review. Critical research questions pertaining to the development and implementation of GEMs for enhanced bioremediation have been identified and posed for possible future research.