Therapeutic Potential of Tuna Backbone Peptide and Its Analogs: An In Vitro and In Silico Study

Tuna backbone peptide (TBP) has been reported to exert potent inhibitory activity against lipid peroxidation in vitro. Since this bears relevant physiological implications, this study was undertaken to assess the impact of peptide modifications on its bioactivity and other therapeutic potential using in vitro and in silico approach. Some TBP analogs, despite lower purity than the parent peptide, exerted promising antioxidant activities in vitro demonstrated by ABTS radical scavenging assay and cellular antioxidant activity assay. In silico digestion of the peptides resulted in the generation of antioxidant, angiotensin-converting enzyme (ACE), and dipeptidyl peptidase-IV (DPPIV) inhibitory dipeptides. Using bioinformatics platforms, we found five stable TBP analogs that hold therapeutic potential with their predicted multifunctionality, stability, non-toxicity, and low bitterness intensity. This work shows how screening and prospecting for bioactive peptides can be improved with the use of in vitro and in silico approaches.     

Detection of intermediates through high-resolution mass spectrometry for constructing biosynthetic pathways for major chemical constituents in a medicinally important herb,Swertia chirayita

Swertia chirayita is an endangered medicinal herb widely used as an antidiabetic. It contains two major classes of metabolites, secoiridoids and xanthones, i.e. swertiamarin, mangiferin, amarogentin and amaroswerin. The biosynthetic pathways for these chemical constituents are not completely deciphered due to gaps and redundancy of routes proposed such as for mangiferin. The missing intermediates in pathways were detected through LC-ESI-QToF-HRMS/MS, including the detection of new secoiridoids, amaronitidin and gentiopicroside. The study also reports that the biosynthesis of amaronitidin occurs through the coupling of gentiopicroside and biphenyl acid derivatives such as amarogentin and amaroswerin. This study reports for the first time complete biosynthetic pathways for gentiopicroside, mangiferin, amarogentin, amaroswerin and amaronitidin in S. chirayita with the detection of intermediate metabolites iriflophenone, maclurin, deoxyloganic acid, loganic acid and 1,3,6,7-tetrahydroxy-9H-xanthen-9-one.     

Off-line integration of CE and MALDI-MS using a closed-open-closed microchannel system

In this work, a new technique for off-line hyphenation between CE and MALDI-MS is presented. Two closed fused-silica capillaries were connected via a silicon chip comprising an open microcanal. The EOF in the system was evaluated using mesityloxide or leucine-enkephalin as a sample and with a running buffer that rendered the analyte neutrally charged. Comparison was made between the EOF in a closed system (first capillary solely included in the electrical circuit) and in a closed-open system (first capillary and microcanal included in the electrical circuit). It was concluded that the experimental values of the EOF agreed with the theory. The influence of the capillary outer diameter on the peak dispersion was investigated using a closed-open-closed system (first capillary, microcanal and second capillary included in the electrical circuit). It was clearly seen that a capillary with 375 microm od induced considerably higher peak dispersion than a 150 microm od capillary, due to a larger liquid dead volume in the connection between the first capillary outlet and the microcanal. Mass spectrometric analysis has also been performed following CE separation runs in a closed-open-closed system with cytochrome c and lysozyme as model proteins. It was demonstrated that a signal distribution profile of the separated analytes could be recorded over a 30 mm long microcanal.     

Evaluating a novel gasoline surrogate containing isopentane using a rapid compression machine and an engine

Simple surrogate formulations for gasoline are useful for modelling purposes and for comparing experimental results using a carefully designed fuel. Simple three-component surrogates based on primary reference fuels (PRF) and Toluene (TPRF) are frequently used to match the antiknock properties of actual gasoline fuels through the RON and MON. However, using PRF or TPRFs to test or to calibrate gasoline engines is still challenging, with the main difficulty being the capabilities of PRF fuels to match the physical properties of the road fuel such density, volatility (DVPE) and the distillation curve. To overcome such issues, an alternative to TPRF is presented in this work with a focus on premium fuel (RON98 EN228). This alternative consists of replacing some or all of isooctane by isopentane. In the event of total replacement, a three-component “THIP” (Toluene, Heptane, IsoPentane) surrogate fuel is produced. The physical and combustion properties of isopentane makes it easier to create surrogates that can match the DVPE, RON, MON and distillation characteristics of a real fuel. Furthermore, the use of isopentane allows the definition of a wider range of surrogate fuel compositions that can replicate the RON and MON of a given fuel. Surrogate formulations were developed at Shell Global Solutions that matched the RON, MON and selected physical properties of a reference premium gasoline (RPG). A Rapid Compression Machine (RCM) in PCFC was used to demonstrate that those surrogates can reproduce the essential autoignition characteristics of the selected RPG. Two mechanisms were used to predict RCM data and showed reasonable agreement, opening some perspective for further investigations. Finally, an engine test performed at Ferrari test facilities demonstrated that simple surrogates containing isopentane can be used to closely match the knock-limited combustion phasing of an RPG. In this paper, it is demonstrated such surrogates have advantages compared to TPRFs in being able to match the properties of a real fuel and that the surrogate approach is consistent with RCM data and engine results.     

Discovering Intrinsic Magnetism of Silk Fibroins

Silk fibroin (SF) is an interesting biomaterials with intriguing mechanical, optical, piezoelectric, and biocompatible properties. The present study reports the first magnetic experiments to show that organic radicals in the building blocks of SF induce permanent magnetization in these materials. A saturation magnetization of 2.8 × 10⁻³ emu g⁻¹ and non-zero remnant magnetization of 2.2 × 10⁻⁴ emu g⁻¹ with a coercive field of 65 Oe is observed in multiple SFs. Tightly bound β-sheets of polyglycine-alanine motifs provides sufficient steric hinderance to organic radicals and protects them from attack of reactive species. Moreover, it also shows that silk's ferromagnetic character can be enhanced by simple mechanical stretching and heating. This work demonstrates a new paradigm of magnetic proteins and opens a route toward the biomimetic discovery of iron-free magnetic proteins.     

Suppression of Interference Caused by Fragment Brownian Movement through the Utilisation of Fuzzy Formulation

The proposed fuzzy composition-based filtering method aims to remove a presence of fractal Brownian noise in the MR brain images. The fractional Brownian motion (FBM) noise is a continuous time Gaussian processed noise and it''s very difficult to identify the positions and range of noise density level, due to a smoothed noise. The projected fuzzy scheme encloses an equivalent fuzzy interference scheme, a fuzzy average procedure and a fuzzy composition procedure. The noise subtraction scheme has been confirmed to be the finest while the depiction is tainted by means of \textit{fractional Brownian motion}. With an average o/p Peak Signal to Noise Ratio(PSNR) of 37.22 and an average noisy image PSNR of 20.28, the average PSNR rate has improved by 16.94. In addition, the average mean square error (MSE) rate has decreased from 609.48 to 12.33 percent. An experimental result confirms that the fuzzy filtering achieves an outstanding eminence of reinstated images in terms of PSNR and MSE without the assistance of noiseless depiction.     

Living with lambda

This talk presents a brief overview of recent results pertaining to the cosmological constant ‘A’. I summarize the observational situation focussing on observations of high redshift Type Ia supernovae which suggest A > 0. Observations of small angular anisotropies in the cosmic microwave background complement Type Ia supernovae observations and both CMB and Sn can be combined to place strong constraints on the value of A. The presence of a small A-term increases the age of the universe and slows down the formation of large scale structure. I also review recent theoretical attempts to generate a small A-term at the current epoch and a model independent approach for determining the cosmic equation of state.     

Partially Ion-Paired Solvation Structure Design for Lithium-Sulfur Batteries under Extreme Operating Conditions

Achieving increased energy density under extreme operating conditions remains a major challenge in rechargeable batteries. Herein, we demonstrate an all-fluorinated ester-based electrolyte comprising partially fluorinated carboxylate and carbonate esters. This electrolyte exhibits temperature-resilient physicochemical properties and moderate ion-paired solvation, leading to a half solvent-separated and half contact-ion pair in a sole electrolyte. As a result, facile desolvation and preferential reduction of anions/fluorinated co-solvents for LiF-dominated interphases are achieved without compromising ionic conductivity (>1 mS cm⁻¹ even at −40 °C). These advantageous features were found to apply to both lithium metal and sulfur-based electrodes even under extreme operating conditions, allowing stable cycling of Li || sulfurized polyacrylonitrile (SPAN) full cells with high SPAN loading (>3.5 mAh cm⁻²) and thin Li anode (50 μm) at −40, 23 and 50 °C. This work offers a promising path for designing temperature-resilient electrolytes to support high energy density Li metal batteries operating in extreme conditions.     

Augmenting the immersed boundary method with Radial Basis Functions (RBFs) for the modeling of platelets in hemodynamic flows

We present a new computational method by extending the immersed boundary (IB) method with a geometric model based on parametric radial basis function (RBF) interpolation of the Lagrangian structures. Our specific motivation is the modeling of platelets in hemodynamic flows, although we anticipate that our method will be useful in other applications involving surface elasticity. The efficacy of our new RBF‐IB method is shown through a series of numerical experiments. Specifically, we test the convergence of our method and compare our method with the traditional IB method in terms of computational cost, maximum stable time‐step size, and volume loss. We conclude that the RBF‐IB method has advantages over the traditional IB method and is well‐suited for modeling of platelets in hemodynamic flows. Copyright © 2015 John Wiley & Sons, Ltd.     

The Rise and Fall of Anomalies in Tetrahedral Liquids

The thermodynamic liquid-state anomalies and associated structural changes of the Stillinger-Weber family of liquids are mapped out as a function of the degree of tetrahedrality of the interaction potential, focusing in particular on tetrahedrality values suitable for modeling C, H₂O, Si, Ge and Sn. We show that the density anomaly, associated with a rise in molar volume on isobaric cooling, emerges at intermediate tetrahedralities (e.g. Ge, Si and H₂O) but is absent in the low (e.g. Sn) and high (e.g. C) tetrahedrality liquids. The rise in entropy on isothermal compression associated with the density anomaly is related to the structural changes in the liquid using the pair correlation entropy. An anomalous increase in the heat capacity on isobaric cooling exists at high tetrahedralities but is absent at low tetrahedralities (e.g. Sn). Structurally, this heat capacity anomaly originates in a sharp rise in the fraction of four-coordinated particles and local tetrahedral order in the liquid as its structure approaches that of the tetrahedral crystal.