Crucial Role of the Chaperonin GroES/EL for Heterologous Production of the Soluble Methane Monooxygenase from Methylomonas methanica MC09

Methane is a widespread energy source and can serve as an attractive C1 building block for a future bioeconomy. The soluble methane monooxygenase (sMMO) is able to break the strong C−H bond of methane and convert it to methanol. The high structural complexity, multiplex cofactors, and unfamiliar folding or maturation procedures of sMMO have hampered the heterologous production and thus biotechnological applications. Here, we demonstrate the heterologous production of active sMMO from the marine Methylomonas methanica MC09 in Escherichia coli by co-synthesizing the GroES/EL chaperonin. Iron determination, electron paramagnetic resonance spectroscopy, and native gel immunoblots revealed the incorporation of the non-heme diiron centre and homodimer formation of active sMMO. The production of recombinant sMMO will enable the expansion of the possibilities of detailed studies, allowing for a variety of novel biotechnological applications.     

Compaction and relaxation characteristics of single compacts produced from distiller’s spent grain

Compaction and relaxation characteristics of densified distiller’s spent grain compacts produced at different levels of compressive pressure (60.3–135.7 MPa), initial moisture content (15%, 20% and 25% wb) and soluble content (15% and 30%) were analyzed during the study. The compaction levels used in this study caused up to a 4% wb reduction in the moisture of compacts in comparison to their initial moisture. The density of compacts was analyzed to determine the compaction characteristics of distiller’s spent grain using Jones model. Analysis of the Jones model showed that there was a significant (P = 0.004) decrease in compressibility with an increase in soluble content from 0% to 30%. The distiller’s spent grain compacts were subjected to relaxation tests and the relaxation data obtained were normalized and analyzed to determine the asymptotic modulus (E_A) of the compacts. The asymptotic modulus was used as a measure of rigidity of the compacts. Distiller’s spent grain compact produced with a compressive force of 135.7 MPa and initial moisture of 25% wb possessed the highest E_A value.     

Thermal modeling of a dual-purposed snap biopsy acquisition procedure in a suspected cancerous lesion

The needle-based biopsy procedure is common in cancer detection and patient-specific targeted therapy, wherein a tissue sample from the potential diseased site is acquired and frozen instantly with the help of a coolant medium. While liquid nitrogen (LN₂) is the most widely used coolant for preserving the acquired sample and performing biopsy tests on the same at a later time, cold ischemia leads to inevitable cell degradation beyond a threshold time. In an effort to circumvent this challenge, here we aim to put forward the concept of an integrated biopsy sample acquisition and cryotherapy procedure, by incorporating an exclusively designed cooling circuit in a conventional biopsy-needle for freezing the sample in vivo as soon as it is acquired, while causing cryoablation in the surrounding tissues simultaneously. An enthalpy-based approach is employed to develop a bioheat transfer model for the cryotherapy design, with illustrative simulation data presented for breast cancer. Our model is demonstrated by considering a constant LN₂ cooling temperature of 77.15 K, and cooling powers ranging from 2 to 10 W. The model results elucidate procedure-specific insights such as the thermal penetration depth and the cooling time on being subjected to the cryoablation. The cooling rates thus obtained are further assessed from the simultaneous considerations of cryopreservation and cryosurgery, deriving critical insights on tissue survival and damage for acting as a precursor to patient-specific treatment planning.     

Design and Performance Evaluation of a Novel Dual Tunneling based TFET Considering Trap Charges for Reliability Improvement

Silicon - Interface trap charges originate in the semiconductor while, fabricating the device, which occur due to the process, radiation stimulated impairments, leading to serious reliability...     

Investigation on Effect of Radial and Extended Fins in PCM Heat Sink for LED Cooling

This work focuses on the efficiency of the LED acting as the heat sink containing Phase Change Material (PCM). Three different heat sink configurations (H-1, H-2, and H-3) are used in this study. Input power and the number of fins are altered to find their effect on junction temperatures, luminous flux, and thermal resistance. The junction temperature of heat sink H-3 with PCM decreased by 3.1 % when compared with heat sink devoid of PCM at 10 W. The thermal resistance of the heat sink H-3 is reduced by 18.2 % when compared to its counterpart devoid of PCM at 10 W. The luminous flux of the PCM filled heat sink H-3 is found to increase by 12.15 % against the PCM not filled heat sink H-1 at 10 W. The H-3 heat sink with PCM showed superior performance because of the enhanced natural convection and conduction in bulk PCM with fins, and with added high latent heat capacity of PCM.     

Fly Ash Based Geopolymer Concrete: a Comprehensive Review

Silicon - Manufacturing of ordinary Portland cement is an energy intensive process that emits harmful greenhouse gases in the atmosphere which pollutes the environment. With the surge in...     

Synthesis of bio-based materials from agricultural residues for treatment of petrochemical wastewater

Clean Technologies and Environmental Policy - 4-Carboxybenzaldehyde (4-CBA), a major component of purified terephthalic acid wastewater, is toxic to living organisms and required to be removed...     

Historical perspectives on gas hydrates and citation impact analysis

Gas hydrates, or clathrate hydrates, is a multidisciplinary field of research involving potential applications to the oil and gas industry, energy security, and innovative technological applications with literature referenced back to 1810. The field of gas hydrates or clathrate hydrates has progressed over the past several decades from academic curiosity-driven research to industrially relevant research related to flow assurance and methane hydrates in nature as an energy resource. In the recent few decades, several innovative and sustainable applications have emerged with gas hydrate or clathrate hydrate as a technology enabler. In this work, I present a bibliometric analysis of the field of gas hydrates or clathrate hydrates for the period from 1901 to 2020 from the Web of Science core collection database of Clarivate Analytics. In total, 12 152 journal publications (review and original research articles) were analyzed from Web of Science core collection database spanning 121 years (1901–2020). Top countries, top cited review articles, and original research articles along with top source titles (journals) are identified and highlighted. In addition, the field classifications and citation rate trends have been analyzed and presented. Network visualization maps are presented for countries, sources, and organizations by analysing citations in VOSviewer. Co-occurrence analysis is performed to identify the top keywords and their links through network visualization based on VOSviewer.     

An overview of mono-ethylene glycol synthesis via CO coupling reaction: Catalysts,kinetics, and reaction pathways

Monoethylene glycol (MEG) is a promising chemical and a useful feedstock for the synthesis of several industrial products. The current commercial process of MEG production utilizes petroleum feedstock (ethylene) and an expensive catalyst, and the yield is low. Syngas is an attractive alternate feedstock for MEG. Syngas to MEG proceeds in two steps: the self-closing, green step of carbonylation of alkyl nitrile to produce dialkyl oxalate, and further hydrogenation of oxalate to MEG. Many reviews which focused on catalyst development, reaction mechanisms, and process variables were published earlier. The present work covers the developments in the syngas-to-MEG synthesis process after 2014. It overviews the performance of novel catalyst systems reported in literature. A discussion on reaction pathways and kinetic models is also presented. This work will provide useful insight into syngas-to-MEG conversion.