In the present study, we report the preparation of silver nanoparticles in the range of 10–15 nm with increased stability and enhanced anti-bacterial potency. The morphology of the nanoparticles was characterized by transmission electron microscopy. The antibacterial effect of silver nanoparticles used in this study was found to be far more potent than that described in the earlier reports. This effect was dose dependent and was more pronounced against gram-negative bacteria than gram-positive organisms. Although bacterial cell lysis could be one of the reasons for the observed antibacterial property, nanoparticles also modulated the phosphotyrosine profile of putative bacterial peptides, which could thus affect bacterial signal transduction and inhibit the growth of the organisms.

Thrombotic disorders have emerged as serious threat to society. As anticoagulant and thrombolytic therapies are usually associated with serious bleeding complications, the focus has now shifted to regulating and maintaining platelets in an inactive state. In the present study we show that nanosilver has an innate antiplatelet property and effectively prevents integrin-mediated platelet responses, both in vivo and in vitro, in a concentration-dependent manner. Ultrastructural studies show that nanosilver accumulates within platelet granules and reduces interplatelet proximity. Our findings further suggest that these nanoparticles do not confer any lytic effect on platelets and thus hold potential to be promoted as antiplatelet/antithrombotic agents after careful evaluation of toxic effects.

The extensive use of silver nanoparticles needs a synthesis process that is greener without compromising their properties. The present study describes a novel green synthesis of silver nanoparticles using Guava (Psidium guajava) leaf extract. In order to compare with the conventionally synthesized ones, we also prepared Ag-NPs by chemical reduction. Their optical and morphological characteristics were thoroughly investigated and tested for their antibacterial properties on Escherichia coli. The green synthesized silver nanoparticles showed better antibacterial properties than their chemical counterparts even though there was not much difference between their morphologies. Fourier transform infrared (FTIR) spectroscopic analysis of the used extract and as-synthesized silver nanoparticles suggests the possible reduction of Ag(+) by the water-soluble ingredients of the guava leaf like tannins, eugenol and flavonoids. The possible reaction mechanism for the reduction of Ag(+) has been proposed and discussed. The time-dependent electron micrographs and the simulation studies indicated that a physical interaction between the silver nanoparticles and the bacterial cell membrane may be responsible for this effect. Based on the findings, it seems very reasonable to believe that this greener way of synthesizing silver nanoparticles is not just an environmentally viable technique but it also opens up scope to improve their antibacterial properties.

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We report that liquid crystal elastomers (LCEs), often portrayed as artificial muscles, serve as scaffolds for skeletal muscle cell. A simultaneous microemulsion photopolymerization and cross-linking results in nematic LCE microspheres 10-30 μm in diameter that when conjoined form a LCE construct that serves as the first proof-of-concept for responsive LCE muscle cell scaffolds. Confocal microscopy experiments clearly established that LCEs with a globular, porous morphology permit both attachment and proliferation of C2C12 myoblasts, while the nonporous elastomer morphology, prepared in the absence of a microemulsion, does not. In addition, cytotoxicity and proliferation assays confirm that the liquid crystal elastomer materials are biocompatible promoting cellular proliferation without any inherent cytotoxicity.

Insect pests, such as pantry beetles, are often associated with food contaminations and public health risks. Machine learning has the potential to provide a more accurate and efficient solution in detecting their presence in food products, which is currently done manually. In our previous research, we demonstrated such feasibility where Artificial Neural Network (ANN) based pattern recognition techniques could be implemented for species identification in the context of food safety. In this study, we present a Support Vector Machine (SVM) model which improved the average accuracy up to 85%. Contrary to this, the ANN method yielded ~80% accuracy after extensive parameter optimization. Both methods showed excellent genus level identification, but SVM showed slightly better accuracy  for most species. Highly accurate species level identification remains a challenge, especially in distinguishing between species from the same genus which may require improvements in both imaging and machine learning techniques. In summary, our work does illustrate a new SVM based technique and provides a good comparison with the ANN model in our context. We believe such insights will pave better way forward for the application of machine learning towards species identification and food safety.

Liquid-crystal droplets are of great interest because of their large surface areas, rich phases, and tunable optical properties. The director configuration of liquid-crystal droplets provides a unique optical sign to detect the events occurring at the droplet surface. In this article, we report the alternating bipolar/radial configuration transitions of 4-n-pentyl-4'-cyanobiphenyl (5CB) droplets triggered by the layer-by-layer coating of negatively charged poly(styrenesulfonate sodium (PSS) and positively charged poly(diallyldimethylammonium chloride) (PDADMAC) on the droplet surface. The alternating configuration transitions are due to the interactions of the 5CB with polar versus nonpolar PDADMAC/PSS multilayer coatings. Furthermore, we find that the coating of PDADMAC/PSS multilayers makes the director configuration of the 5CB in the droplets sensitive to environmental salt concentrations.

The concentration level of bile acids is a clinical biomarker for the diagnosis of intestinal diseases because individuals suffering from intestinal diseases have a sharply increased concentration of bile acids at micromolar levels. Here, we report the detection of lithocholic acid (LCA) in aqueous solution by using surfactant-stabilized 4-n-pentyl-4'-cyanobiphenyl (5CB) liquid crystal droplets as an optical probe. We find that the surfactant adsorbed at the 5CB/water interface can be replaced by LCA, triggering a radial-to-bipolar configuration transition of the 5CB in the droplets. By simply observing the LCA-triggered transition with a polarizing optical microscope, micromolar levels of LCA in aqueous solution can be detected. The detection limit and selectivity of surfactant-stabilized 5CB droplets for LCA depend on the chain length and headgroup of the surfactants used for stabilizing 5CB droplets.