Efficient Chemical and Enzymatic Syntheses of FAD Nucleobase Analogues and Their Analysis as Enzyme Cofactors**

Flavin adenine dinucleotide (FAD) is an essential redox cofactor in cellular metabolism. The organic synthesis of FAD typically involves coupling flavin mononucleotide (FMN) with adenosine monophosphate, however, existing synthesis routes present limitations such as multiple steps, low yields, and/or difficult-to-obtain starting materials. In this study, we report the synthesis of FAD nucleobase analogues with guanine/cytosine/uracil in place of adenine and deoxyadenosine in place of adenosine using chemical and enzymatic approaches with readily available starting materials, achieved in 1–3 steps with moderate yields (10–57 %). We find that the enzymatic route using Methanocaldococcus jannaschii FMN adenylyltransferase (MjFMNAT) is versatile and can produce these FAD analogues in high yields. Further, we demonstrate that Escherichia coli glutathione reductase is capable of binding and using these analogues as cofactors. Finally, we show that FAD nucleobase analogues can be synthesized inside a cell from cellular substrates FMN and nucleoside triphosphates by the heterologous expression of MjFMNAT. This lays the foundation for their use in studying the molecular role of FAD in cellular metabolism and as biorthogonal reagents in biotechnology and synthetic biology.     

Prioritizing towards a green export portfolio for India: An environmental input–output approach

Proponents of free trade have often hailed international trade as an engine of economic growth. However, the foreign trade sector, like many other sectors in developing countries, frequently involves these countries walking a tightrope between their developmental objectives and environmental goals. In this regard, prioritizing for developing a ‘green’ yet internationally competitive export portfolio provides a quintessential win–win solution to the problem. This study factors in both environmental benignity (indicated by total CO₂ emission intensity) as well as trade competitiveness (indicated by revealed comparative advantage index) in identifying the ‘ideal’ Indian export portfolio. The analysis calculates the level of direct and indirect emissions from the foreign trade sector (exports and imports) using the environmental input–output (EIO) matrix for 2003/04 for India that has been jointly developed by researchers from Keio University, Japan, and The Energy and Resources Institute (TERI), New Delhi. The derived basket is compared to the current portfolio to estimate the potential saving from compositional changes and to suggest directions for policymaking to emphasize or de-emphasize the export of certain categories of exports.     

Potential of Sr4Al14O25: Eu2+,Dy3+ inorganic oxide-based nanophosphor in Latent fingermark detection

In this paper, the potential of the Sr₄Al₁₄O₂₅: Eu²⁺,Dy³⁺ fluorescent nanophosphor is explored to visualize the latent fingermarks. The nanophosphor has been synthesized using self-propagating high temperature synthesis and shows intense luminescence and strong long after glow properties. These nano particles have been characterized for their particle size, crystalline phase, and photoluminescent properties. The calculated PL CIE co-ordinates (0.138, 0.359) correspond to the blue–green shade. Different porous, non-porous, as well as slightly non-smooth surfaces are taken and successfully tested for latent fingerprints development with the prepared Sr₄Al₁₄O₂₅: Eu²⁺,Dy³⁺ fluorescent nanophosphor powder. Present nano powder is advantageous to use on luminescent or multicolored surfaces as it gives greater contrast and also eliminates the problem of background interferences with the friction ridges due to its strong long after glow property. The results are very good when latent fingerprints were developed on the currency notes with optical variable ink and highly fluorescent pattern areas.     

Parallel and serial heuristics for the minimum set cover problem

We present a theoretical analysis and an experimental evaluation of four serial heuristics and four parallel heuristics for the minimum set cover problem. The serial heuristics trade off run time with the quality of the solution. The parallel heuristics are derived from one of the serial heuristics. These heuristics show considerable speedup when the number of processors is increased. The quality of the solution computed by the heuristics does not degrade with an increase in the number of processors.Research of both authors was supported by NSF Grant No. MIP-8807540.     

Energy conservation : An elasticity of substitution approach

Long-term forecasts of demand, used in energy planning, are based on assumptions alleged to be reasonable at the time of projections. The political debate can then focus on whether these assumptions are indeed reasonable. Common considers two sets of projections, and estimates the implicit price and income elasticities, thereby translating assumptions entailed in two different reports into concepts which are directly comparable. It is argued here that this approach need be taken a step further and elasticities of substitution between energy and other inputs should be calculated. Possibilities of energy conservation could then be taken into account.     

GOX-functionalized nanodiamond films for electrochemical biosensor

The importance of nanodiamond in biological and technological applications has been recognized recently, and applied in drug delivery, biochip, sensors and biosensors. Under this investigation, nanodiamond (ND) and nitrogen doped nanodiamond (NND) were deposited on n-type silicon films, and later functionalized with enzyme Glucose oxidase (GOX). The GOX functionalized doped and undoped ND films were characterized using combination of several techniques; i.e. FTIR spectroscopy, Raman spectroscopy, atomic force microscopy (AFM) and electrochemical techniques. ND/GOX and NND/GOX thin films on n-type silicon have been found to provide sensitive glucose sensor. GOX has been chosen as a model enzyme system to functionalize with ND at molecular level to understand the glucose biosensor.     

Organic photovoltaics using thin gold film as an alternative anode to indium tin oxide

Indium Tin Oxide (ITO) is the most commonly used anode as a transparent electrode and more recently as an anode for organic photovoltaics (OPVs). However, there are significant drawbacks in using ITO which include high material costs, mechanical instability including brittleness and poor electrical properties which limit its use in low-cost flexible devices. We present initial results of poly(3-hexylthiophene): phenyl-C₆₁-butyric acid methyl ester OPVs showing that an efficiency of 1.9% (short-circuit current 7.01 mA/cm², open-circuit voltage 0.55 V, fill factor 0.49) can be attained using an ultra thin film of gold coated glass as the device anode. The initial I-V characteristics demonstrate that using high work function metals when the thin film is kept ultra thin can be used as a replacement to ITO due to their greater stability and better morphological control.     

Strategic Allocation of Inspection Effort In A Serial, Multi-Product Production System

For a multi-stage production system, optimal location of inspection activities is an important consideration in minimizing the inspection-related and salvage costs. Set-up and inventory carrying costs also become important factors when several products are produced on the same line due to the product changeovers involved.

In this paper we discuss the effect of these additional costs (set-up and inventory carrying) on the inspection strategy, i.e., “all or none” versus partial inspection. We suggest a shortest path heuristic to determine the strategic location of inspection activities and the production lot sizes.     

A DELAY-LINE CANCELLATION METHOD FOR CLUTTER ATTENUATION AND ELIMINATION OF BLIND SPEED

In this paper, a conceptual schematic for the search radar has been presented which offers clutter cancellation as well as blind speed elimination. It is assumed that the radar is performing conical scan in both azimuth and elevation. For such cases, strong clutter signals are likely to be intercepted from off-boresight angles. A pulse-to-pulse comparison method is presented where the radar transmits and receives SUM beam during the first pulse and DIFFERENCE beam in the second pulse. The detected voltages for the echoes received during the pulse intervals are subtracted from each other and the negative voltage at the output of subtractor is discarded. This result in a narrow beam pointed in the direction of angle of arrival. This method, in receive only mode, can also be used for calibration of large phased arrays.