Graphene Quantum Dots - From Emergence to Nanotheranostic Applications

Quantum dots are at the cutting edge of nanotechnology development. Due to their unique optical and physical properties, they have potential applications in many avenues of medicine and biotechnology. With the advancements in nano-sciences, novel applications of quantum dots are constantly being explored for drug delivery and bioimaging. Graphene quantum dots (GQDs) are nanoparticles of graphene with properties of quantum dots as well as graphene. GQDs have ignited remarkable research interest in the field of medicine and biology and are considered as well-suited candidates for nanotheranostic applications due to their excellent biocompatibility and tunable physicochemical properties. The promising emerging implications of GQD platforms for diagnostics and therapeutics advances are the basis of this chapter

Divide and Rule: DiFA - Division Property Based Fault Attacks on PRESENT and GIFT

The division property introduced by Todo in Crypto 2015 is one of the most versatile tools in the arsenal of a cryptanalyst which has given new insights into many ciphers primarily from an algebraic perspective. On the other end of the spectrum we have fault attacks which have evolved into the deadliest of all physical attacks on cryptosystems. The current work aims to combine these seemingly distant tools to come up with a new type of fault attack. We show how fault invariants are formed under special input division multi-sets and are independent of the fault injection location. It is further shown that the same division trail can be exploited as a multi-round Zero-Sum distinguisher to reduce the key-space to practical limits. As a proof of concept division trails of PRESENT and GIFT are exploited to mount practical key-recovery attacks based on the random nibble fault model. For GIFT-64, we are able to recover the unique master-key with 30 nibble faults with faults injected at rounds 21 and 19. For PRESENT-80, DiFA reduces the key-space from $2^{80}$ to $2^{16}$ with 15 faults in round 25 while for PRESENT-128, the unique key is recovered with 30 faults in rounds 25 and 24. This constitutes the best fault attacks on these ciphers in terms of fault injection rounds. We also report an interesting property pertaining to fault induced division trails which shows its inapplicability to attack GIFT-128. Overall, the usage of division trails in fault based cryptanalysis showcases new possibilities and reiterates the applicability of classical cryptanalytic tools in physical attacks

Continuous-Flow Dynamic Kinetic Resolution of Racemic Alcohols by Lipase-Oxovanadium Cocatalysis

Higashio K, Katsuragi S, Kundu D, et al. Continuous-Flow Dynamic Kinetic Resolution of Racemic Alcohols by Lipase-Oxovanadium Cocatalysis. European journal of organic chemistry. 2020;2020(13):1961-1967.A continuous-flow dynamic kinetic resolution of racemic secondary alcohols was carried out using a single column reactor packed with a mixture of immobilized lipase and an immobilized oxovanadium species, VMPS4. As a result, optically pure esters were produced in 88-92 % yields. Problems encountered in this study were overcome by using fillers that efficiently maintained the initial distribution of the catalysts in the reactor and by using a packing method in which the mixing ratio of the two catalysts was varied in a stepwise fashion. The flow process led to an increased turnover number of each catalyst compared to those of batch reactions

Temporal Control over Transient Chemical Systems using Structurally Diverse Chemical Fuels

The next generation of adaptive, intelligent chemical systems will rely on a continuous supply of energy to maintain the functional state. Such systems will require chemical methodology that provides precise control over the energy dissipation process, and thus, the lifetime of the transiently activated function. This manuscript reports on the use of structurally diverse chemical fuels to control the lifetime of two different systems under dissipative conditions: transient signal generation and the transient formation of self-assembled aggregates. The energy stored in the fuels is dissipated at different rates by an enzyme, which in-stalls a dependence of the lifetime of the active system on the chemical structure of the fuel. In the case of transient signal generation, it is shown that different chemical fuels can be used to generate a vast range of signal profiles, allowing temporal control over two orders of magnitude. Regarding self-assembly under dissipative conditions, the ability to control the lifetime using different fuels turns out to be particularly important as stable aggregates are formed only at well-defined surfactant/fuel ratios, meaning that temporal control cannot be achieved by simply changing the fuel concentration

Of cattle, sand flies and men : a systematic review of risk factor analyses for South Asian visceral leishmaniasis and implications for elimination

Background: Studies performed over the past decade have identified fairly consistent epidemiological patterns of risk factors for visceral leishmaniasis (VL) in the Indian subcontinent. Methods and Principal Findings: To inform the current regional VL elimination effort and identify key gaps in knowledge, we performed a systematic review of the literature, with a special emphasis on data regarding the role of cattle because primary risk factor studies have yielded apparently contradictory results. Because humans form the sole infection reservoir, clustering of kala-azar cases is a prominent epidemiological feature, both at the household level and on a larger scale. Subclinical infection also tends to show clustering around kala-azar cases. Within villages, areas become saturated over a period of several years; kala-azar incidence then decreases while neighboring areas see increases. More recently, post kalaazar dermal leishmaniasis (PKDL) cases have followed kala-azar peaks. Mud walls, palpable dampness in houses, and peridomestic vegetation may increase infection risk through enhanced density and prolonged survival of the sand fly vector. Bed net use, sleeping on a cot and indoor residual spraying are generally associated with decreased risk. Poor micronutrient status increases the risk of progression to kala-azar. The presence of cattle is associated with increased risk in some studies and decreased risk in others, reflecting the complexity of the effect of bovines on sand fly abundance, aggregation, feeding behavior and leishmanial infection rates. Poverty is an overarching theme, interacting with individual risk factors on multiple levels. Conclusions: Carefully designed demonstration projects, taking into account the complex web of interconnected risk factors, are needed to provide direct proof of principle for elimination and to identify the most effective maintenance activities to prevent a rapid resurgence when interventions are scaled back. More effective, short-course treatment regimens for PKDL are urgently needed to enable the elimination initiative to succeed

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Modern MAP Inference Methods for Accurate and Fast Occupancy Grid Mapping on Higher Order Factor Graphs

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.DOI: 10.1109/ICRA.2014.6907129Using the inverse sensor model has been popular in occupancy grid mapping. However, it is widely known that applying the inverse sensor model to mapping requires certain assumptions that are not necessarily true. Even the works that use forward sensor models have relied on methods like expectation maximization or Gibbs sampling which have been succeeded by more effective methods of maximum a posteriori (MAP) inference over graphical models. In this paper, we propose the use of modern MAP inference methods along with the forward sensor model. Our implementation and experimental results demonstrate that these modern inference methods deliver more accurate maps more efficiently than previously used methods

Structural and Physical Properties of Fe2O3-B2O3-V2O5 Glasses

The structural and physical properties of xFe2O3-(40-x) B2O3-60V2O5  (0≤x≤20) glass system have been investigated. The samples were prepared by normal melt-quench technique. The structural changes were inferred by means of FTIR by monitoring the infrared (IR) spectra in the spectral range 600–4000 cm-1. The absence of boroxol ring (806 cm-1) in the present glass system suggested that these glasses consist of randomly connected BO3 and BO4 units. The conversion of BO3 to BO4 and VO5 to VO4 tetrahedra along with the formation of non-bridging oxygen's (NBOs) attached to boron and vanadium takes place in the glasses under investigation. The density and molar volume of the present glass system were found to depend on Fe2O3 content. DC conductivity of the glass system has been determined in the temperature range 310–500 K. It was found that the general behavior of electrical conductivity was similar for all glass compositions and found to increase with increasing iron content. The parameters such as activation energy, average separation between transition metal ions (TMIs), polaron radius, and so forth have been calculated in adiabatic region and are found consistent with Mott's model of phonon-assisted polaronic hopping

Photocatalytic Degradation of Congo Red and Methyl Orange Dye Under Visible Light Using Silver and Iron co-doped TiO2 Nanoparticles

In the present report TiO2 nanoparticles co-doped with iron and different mol % of silver have been successfully synthesized by sol-gel route and studied by X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX), UV-visible absorption spectroscopy (UV-Vis), Photoluminescence spectroscopy (PL), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), and FTIR spectroscopy. The XRD data analysis confirms the formation of mixed phases of TiO2 (anatase) and Ag2O phase. The crystalline size was vary from 48.0 nm to 44.6 nm determined from XRD further verified from TEM micrograph. The EDXS measurements suggest that iron is completely incorporated however silver has not incorporated into TiO2 matrix. The optical band gap of the prepared nanoparticles was calculated by UV-Visible absorption spectroscopy using Tauc-Davis and Mott expression and found to varying from 2.92 to 2.30 eV. The absorption bands in the UV-visible spectra shift towards higher wave length region and appearance of emission bands in PL spectra confirms the formation of energy substates in the forbidden gap of the prepared samples. TEM micrographs showed that prepared nanoparticles are somewhat spherical in shape. The formation of different functional groups and bonds in the structure of synthesized nanoparticles as observed in FTIR spectra helps in degradation of organic dyes (congo red and methyl orange) and enhance the photocatalytic activity under visible light. It is observed that the higher doping concentration of silver causes to decrease the band gap energy as a result the carrier recombination rate decreases and therefore enhance the degradation efficiency