Resonance Raman Spectroscopy of the Oxygenated Intermediates of Human CYP19A1 Implicates a Compound I Intermediate in the Final Lyase Step

CYP19A1, or aromatase, a cytochrome P450 responsible for estrogen biosynthesis in humans, is an important therapeutic target for the treatment of breast cancer. There is still controversy surrounding the identity of reaction intermediate that catalyzes carbon–carbon scission in this key enzyme. Probing the oxy-complexes of CYP19A1 poised for hydroxylase and lyase chemistries using resonance Raman spectroscopy and drawing a comparison with CYP17A1, we have found no significant difference in the frequencies or isotopic shifts for these two steps in CYP19A1. Our experiments implicate the involvement of Compound I in the terminal lyase step of CYP19A1 catalysis

Pion-Nucleon Scattering Relations at Next-to-Leading Order in 1/N_c

We obtain relations between partial-wave amplitudes for pi-N-->pi-N and pi-N-->pi-Delta directly from large N_c QCD. While linear relations among certain amplitudes holding at leading order (LO) in 1/N_c were derived in the context of chiral soliton models two decades ago, the present work employs a fully model-independent framework based on consistency with the large N_c expansion. At LO we reproduce the soliton model results; however, this method allows for systematic corrections. At next-to-leading order (NLO), most relations require additional unknown functions beyond those appearing at leading order (LO) and thus have little additional predictive power. However, three NLO relations for the pi-N-->pi-Delta reaction are independent of unknown functions and make predictions accurate at this order. The amplitudes relevant to two of these relations were previously extracted from experiment. These relations describe experiment dramatically better than their LO counterparts.Comment: 8 pages, 2 figures; references adde

A Discussion on Uncertainty Representation and Interpretation in Model-Based Prognostics Algorithms based on Kalman Filter Estimation Applied to Prognostics of Electronics Components

This article discusses several aspects of uncertainty representation and management for model-based prognostics methodologies based on our experience with Kalman Filters when applied to prognostics for electronics components. In particular, it explores the implications of modeling remaining useful life prediction as a stochastic process and how it relates to uncertainty representation, management, and the role of prognostics in decision-making. A distinction between the interpretations of estimated remaining useful life probability density function and the true remaining useful life probability density function is explained and a cautionary argument is provided against mixing interpretations for the two while considering prognostics in making critical decisions

Design of Small Scale Anaerobic Digester for Application in Indian Village: A Review

Proper choosing of design of anaerobic digester and estimation of it size is an important point in the successful implementation of anaerobic digester. The end users of anaerobic digester in most cases are farmers whose technical knowledge of the systems is limited. And there is a lack of information available on design methods for these systems. The goals of this study were to develop literature that could be used by laymen to decide the design and size of anaerobic digester. To develop a design formula that could be used for anaerobic digester sizing based on livestock waste availability. The case studies were conducted on three scales: one household, six households, and a village of 67 and 28 households. The biogas produced in case study for one household was0.44 m3, for six household was 2.60 m3, for Kapurpur village of 67 household was 11.33 m3

Analysis of a Rotating Spool Expander for Organic Rankine Cycles in Heat Recovery Applications

The increasing cost of energy, coupled with the recent drive for energy security and climate change mitigation have provided the impetus for harnessing renewable energy sources as viable alternatives to conventional fossil fuels. Furthermore, recovering heat that is discharged from power plants, automobiles and various other industrial processes is of growing interest. Nevertheless, technologies attempting to provide small-scale heat recovery solutions have seen very limited commercialization. This is broadly due to two reasons: lack of historical research and development in the area of waste-heat recovery and small-scale power generation due to technical and cost impediments; and technical challenges associated with scaling the technology from utility-scale to commercial-scale, particularly with regard to expansion machines (turbines). However, due to rising primary energy costs and the environmental premium being placed on fossil fuels, the conversion from low-grade heat to electrical energy as well as small-scale distributed power generation is of increasing interest. In this regard, this project focuses on a novel rotating spool expansion machine at the heart of an Organic Rankine Cycle (ORC), which in turn is used as a heat recovery system. A comprehensive simulation model of the rotating spool expander is presented. The spool expander provides a new rotating expansion mechanism with easily manufactured components. Apart from efficiency improvements compared with other rotary machines, the spool expander also has the ability to control the expansion ratio using a novel mechanically-driven suction valve mechanism. Another advantage is the relocation of the face sealing surfaces to the outer radius of the device. The spool expander is also scalable to a size range (50-200 kW) that is too large for conventional positive displacement machines, and too small for dynamic machines with respect to manufacturability, efficiency and cost. A detailed analytical geometry model of the spool expander and the suction valve mechanism is presented. This geometry model forms a part of a comprehensive model that includes submodels for friction, leakage, and heat transfer. The results of the comprehensive model are validated using experimental data from a 50 kW prototype expander in an ORC system. Given the promise of the technology, this paper explores the design space using both a simulation based approach as well as an experimental prototype for concept validation

EVALUATION OF BURN WOUND HEALING ACTIVITY OF TOPICAL REGULAR INSULIN IN NON-DIABETIC AND STREPTOZOCIN-INDUCED DIABETIC RATS

Objective: The role of insulin in the regulation of energy metabolism, protein synthesis, cell differentiation and growth suggests that this hormone could also play an essential role in regulation of wound healing. Consequently, the aim of the present study was to investigate the effects of topical insulin administration on burn wound healing in both non-diabetic and streptozocin-induced diabetic Wistar rats. Methods: Wound healing activity was assessed by burn-wound model. This study was conducted using six groups of Wistar strain adult rats of either sex (n = 6). First three groups were non-diabetic (ND) rats and the other three had diabetic (D) rats: (i) ND control (sterile water); (ii) ND standard (silver sulfadiazine cream); (iii) ND test (topical Insulin); (iv) D control (sterile water); (v) D standard (silver sulfadiazine cream); (vi) D test (topical insulin). Wound healing was assessed by wound contraction rate and complete epithelialization time. Results: There was significant (p<0.05) delay in wound healing in diabetic rats when compared to normal rats. It was found that topical insulin administration enhanced burn wound healing by shortening the time needed for complete epithelialization in the non-diabetic and diabetic group. Conclusion: This study revealed that topical insulin application to partial thickness burn wounds accelerates wound healing in rats with or without acute diabetes