Multiscale Investigation of Sodium-Ion Battery Anodes: Analytical Techniques and Applications

The anode/electrolyte interface behavior, and by extension, the overall cell performance of sodium-ion batteries is determined by a complex interaction of processes that occur at all components of the electrochemical cell across a wide range of size- and timescales. Single-scale studies may provide incomplete insights, as they cannot capture the full picture of this complex and intertwined behavior. Broad, multiscale studies are essential to elucidate these processes. Within this perspectives article, several analytical and theoretical techniques are introduced, and described how they can be combined to provide a more complete and comprehensive understanding of sodium-ion battery (SIB) performance throughout its lifetime, with a special focus on the interfaces of hard carbon anodes. These methods target various length- and time scales, ranging from micro to nano, from cell level to atomistic structures, and account for a broad spectrum of physical and (electro)chemical characteristics. Specifically, how mass spectrometric, microscopic, spectroscopic, electrochemical, thermodynamic, and physical methods can be employed to obtain the various types of information required to understand battery behavior will be explored. Ways are then discussed how these methods can be coupled together in order to elucidate the multiscale phenomena at the anode interface and develop a holistic understanding of their relationship to overall sodium-ion battery function.     

Conjugation of Multiple Copies of Polyethylene Glycol to Hemoglobin Facilitated Through Thiolation: Influence on Hemoglobin Structure and Function

PEGylation induced changes in molecular volume and solution properties of HbA have been implicated as potential modulators of its vasoconstrictive activity. However, our recent studies with PEGylated Hbs carrying two PEG chains/Hb, have demonstrated that the modulation of the vasoconstrictive activity of Hb is not a direct correlate of the molecular volume and solution properties of the PEGylated Hb and implicated a role for the surface charge and/or the pattern of surface decoration of Hb with PEG. HbA has now been modified by thiolation mediated maleimide chemistry based PEGylation that does not alter its surface charge and conjugates multiple copies of PEG5K chains. This protocol has been optimized to generate a PEGylated Hb, (SP-PEG5K)₆-Hb, that carries ~six PEG5K chains/Hb – HexaPEGylated Hb. PEGylation increased the O₂ affinity of Hb and desensitized the molecule for the influence of ionic strength, pH, and allosteric effectors, presumably a consequence of the hydrated PEG-shell generated around the protein. The total PEG mass in (SP-PEG5K)₆-Hb, its molecular volume, O₂ affinity and solution properties are similar to that of another PEGylated Hb, (SP-PEG20K)₂-Hb, that carries two PEG20K chains/Hb. However, (SP-PEG5K)₆-Hb exhibited significantly reduced vasoconstriction mediated response than (SP-PEG20K)₂-Hb. These results demonstrate that the enhanced molecular size and solution properties achieved through the conjugation of multiple copies of small PEG chains to Hb is more effective in decreasing its vasoconstrictive activity than that achieved through the conjugation of a comparable PEG mass using a small number of large PEG chains.     

The Differential Reaction of Rice Hybrids to Tungro Virus by Phenotyping and PCR Analysis

Twenty popular rice hybrids were used to screen for rice tungro virus (RTV) disease reaction. Virulent green leafhoppers (GLH) were used as vector to introduce RTV to the rice hybrids. Virus symptoms scores were recorded at 14, 21, 34, 41 and 59 days postinoculation (DPI), which suggested that virus symptoms are greatly influenced by growth stage of plants. To confirm the presence of virus, polymerase chain reaction (PCR)‐based detection of Rice tungro bacilliform virus (RTBV) was carried out at 7, 14, 21 and 59 DPI using virus genome‐specific primers. Virus presence was observed in all the rice hybrids and check varieties, particularly at later stages of infection. This study shows that phenotyping for tungro virus resistance in rice hybrids at 21 DPI gives most reliable results based on both virus symptoms and presence of virus. Further, to assess the relative difference in population of RTBV, quantitative PCR was performed in all the genotypes at 21 DPI. Yield data were also recorded from control and virus‐infected plants to estimate yield loss percentage due to tungro disease. This study is important to understand the response of rice hybrids to tungro virus disease. Results obtained in this study emphasize that molecular detection of virus is very important to screen the rice plants accurately for tungro disease reaction.     

OrFin: A web tool for detection of putative orthologs

Identification of ortholog is one of the important tasks to understand a novel genome. It helps to assign functional annotations, from one organism to another organism. To identify the putative ortholog, Reciprocal Best BLAST hit (RBBH) method is known to be an efficient approach. OrFin makes use of the same approach to identify pair of orthologous proteins for a given set of sequences of two species. It is a user-friendly web tool which works with user defined parameters to search RBBHs. Results are produced in both html and text format.

Availability

This web tool is freely available at http://bifl.uohyd.ac.in/orfin     

Antioxidants prevent UV-induced apoptosis by inhibiting mitochondrial cytochrome c release and caspase activation in Spodoptera frugiperda (Sf9) cells

Oxidative stress has been shown to be associated with apoptosis (programmed cell death) in a number of cell systems. We earlier reported in vitro cultured Spodoptera frugiperda (Sf9) cells as a model system to study oxidative stress induced apoptosis (J Biosciences 24 (1999) 13) and the inhibition of UV-induced apoptosis by the baculovirus antiapoptotic p35 protein that acts as a sink to sequester reactive oxygen species (Proc Natl Acad Sci USA 96 (1999) 4838). We now show that UV-induced apoptosis in Sf9 cells, is preceded by the release of mitochondrial cytochrome c into the cytosol and consequent activation of Sf-caspase-1. The inhibitory effect of different antioxidants including scavengers of oxygen radicals such as butylated hydroxyanisole (BHA), alpha tocopherol acetate, benzoate and reduced-glutathione (GSH) on ultra violet B (UVB)-induced apoptosis in cultured Sf9 cells was assessed. Both, cytochrome c release as well as Sf-caspase-1 activation was inhibited by pre-treatment with antioxidants such as BHA and alpha tocopherol acetate, suggesting that these antioxidants inhibit apoptosis by acting quite upstream in the apoptosis cascade at the mitochondrial level, as well as downstream at the caspase level.     

MRI denoising using nonlocal neutrosophic set approach of Wiener filtering

In this paper, a new filtering method is presented to remove the Rician noise from magnetic resonance images (MRI) acquired using single coil MRI acquisition system. This filter is based on nonlocal neutrosophic set (NLNS) approach of Wiener filtering. A neutrosophic set (NS), a part of neutrosophy theory, studies the origin, nature, and scope of neutralities, as well as their interactions with different ideational spectra. Now, we apply the neutrosophic set into image domain and define some concepts and operators for image denoising. First, the nonlocal mean is applied to the noisy MRI. The resultant image is transformed into NS domain, described using three membership sets: true (T), indeterminacy (I) and false (F). The entropy of the neutrosophic set is defined and employed to measure the indeterminacy. The ω-Wiener filtering operation is used on T and F to decrease the set indeterminacy and to remove the noise. The experiments have been conducted on simulated MR images from Brainweb database and clinical MR images. The results show that the NLNS Wiener filter produces better denoising results in terms of qualitative and quantitative measures compared with other denoising methods, such as classical Wiener filter, the anisotropic diffusion filter, the total variation minimization and the nonlocal means filter. The visual and the diagnostic quality of the denoised image are well preserved.     

Optimization of extracellular thermotolerant alkaline protease produced by marine <Emphasis Type="Italic">Roseobacter</Emphasis> sp. (MMD040)

Marine endosymbiontic Roseobacter sp. (MMD040), which produced high yields of protease, was isolated from marine sponge Fasciospongia cavernosa, collected from the peninsular coast of India. Maximum production of enzyme was obtained in Luria-Bertani broth. Catabolite repression was observed when the medium was supplemented with readily available carbon sources. The optimum temperature and pH for the enzyme production was 37 degrees C and 7.0, respectively. The enzyme exhibited maximum activity in pH range of 6-9 with an optimum pH of 8.0 and retained nearly 92.5% activity at pH 9.0. The enzyme was stable at 40 degrees C and showed 89% activity at 50 degrees C. Based on the present findings, the enzyme was characterized as thermotolerant alkaline protease, which can be developed for industrial applications.