DDX3X loss is an adverse prognostic marker in diffuse large B-cell lymphoma and is associated with chemoresistance in aggressive non-Hodgkin lymphoma subtypes.

Funder: addenbrooke's charitable trust, cambridge university hospital

Electrochemistry: A basic and powerful tool for micro- and nanomotor fabrication and characterization

Electrochemistry, although an ancient field of knowledge, has become of paramount importance in the synthesis of materials at the nanoscale, with great interest not only for fundamental research but also for practical applications. One of the promising fields in which electrochemistry meets nanoscience and nanotechnology is micro/nanoscale motors. Micro/nano motors, which are devices able to perform complex tasks at the nanoscale, are commonly multifunctional nanostructures of different materials - metals, polymers, oxides- and shapes -spheres, wires, helices- with the ability to be propelled in fluids. Here, we first introduce the topic of micro/nanomotors and make a concise review of the field up to day. We have analyzed the field from different points of view (e.g. materials science and nanotechnology, physics, chemistry, engineering, biology or environmental science) to have a broader view of how the different disciplines have contributed to such exciting and impactful topic. After that, we focus our attention on describing what electrochemical technology is and how it can be successfully used to fabricate and characterize micro/nanostructures composed of different materials and showing complex shapes. Finally, we will review the micro and nanomotors fabricated using electrochemical techniques with applications in biomedicine and environmental remediation, the two main applications investigated so far in this field. Thus, different strategies have thus been shown capable of producing core-shell nanomaterials combining the properties of different materials, multisegmented nanostructures made of, for example, alternating metal and polymer segments to confer them with flexibility or helicoidal systems to favor propulsion. Moreover, further functionalization and interaction with other materials to form hybrid and more complex objects is also shown

Iterative (turbo) detection and stopping criterions for CDMA channel

In this thesis, we propose an iterative (turbo) detector for CDMA channel using cross entropy minimization.Master of Engineerin

SINGAPORE INVESTORS IN OVERSEAS PROPERTY MARKETS

BACHELOR OF SCIENCE (ESTATE MANAGEMENT

SINGAPORE INVESTORS IN OVERSEAS PROPERTY MARKETS

Bachelor'sBACHELOR OF SCIENCE (ESTATE MANAGEMENT

Influence of impurities on the electrochemistry of carbon nanotubes and the toxicity of nanomaterials

Carbon nanomaterials such as carbon nanotubes and graphene are well recognized for their exceptional physical, structural and electronic properties that can be exploited for a wide range of electrochemical and biomedicine applications. Owing to the inherent electrocatalytic property of carbon nanotubes, their application as an electrochemical material has reportedly led to lowered overpotentials as well as enhanced redox reactions. However, all of these were elucidated to be due to the presence of metallic and carbonaceous impurities within carbon nanotubes which acted as electroactive sites. This project will expand on the influence of impurities on the electrochemistry of carbon nanotubes, and introduce an improved purification technique for an efficient removal of these impurities. With the subsequent discovery of graphene, their potential use in applications was modelled after carbon nanotubes. Along with the advent of graphene synthesis methods, numerous graphene-family nanomaterials were produced and these were explored for their use in numerous biomedicine applications. Consequently, concerns were raised about their possible nanotoxicological impact but the variations in their physiochemical properties have made it challenging to evaluate their toxicities. This project will investigate the toxicity effects of multiple derivatives of graphene, and this is also extended to include molybdenum sulfide which is another 2D material as well as nanomotors. All these are integral to the continuing efforts on nanosafety research as part of the rapid advancements in nanotechnology. ​Doctor of Philosophy (SPMS

In-situ infra-red spectroscopy of reduced forms of vitamin K1.

Infra-red spectra of the redox products of Vitamin K1 (VK1) were obtained in order to acquire information on the positions of their characteristic bands. We have investigated the reduction processes of VK1 in acetonitrile containing 0.2 M Bu4NPF6 as the supporting electrolyte with an amalgamation of electrochemistry techniques and in-situ infra-red spectroscopy. A spectroelectrochemical cell with a glass frit fitted at the bottom was used as the cathodic compartment to produce redox products and to allow monitoring of the electrolysis process simultaneously in the infra-red spectral range. In acetonitrile, two chemically reversible one-electron transfer reactions were detected via cyclic voltammetry and the E0 values obtained from it were used to determine the potentials for generating the reduced products during constant potential electrolysis. The reduction processes were also conducted at very low water concentrations and it was found that the second reduction step could not proceed due to the reduced forms undergoing adsorptive process with the electrode surface. The effect of water on the shifting of infra-red bands for both reduction processes was investigated and it was revealed that only bands belonging to the second reduced product were affected. The sequential addition low volumes of water (0 μL - 100 μL) to the VK1 in dry acetonitrile without Bu4NPF6 was discovered to cause a dramatic increase of approximately twenty-fold in the intensities of the absorbance bands belonging to VK1. Hydrogen bonding effect and solubility effect are the two plausible reasons deduced to explain the effects observed. The hydrogen bonding effect was investigated by using dimethyl terephthalate and VK1 model compound; and the solubility effect examined by using Vitamin E to find out which is responsible for the effect we observe on the intensities of the bands so as to have a better understanding of how VK1 is able to interact with water.Bachelor of Science in Chemistry and Biological Chemistr

The toxicity of graphene oxides : dependence on the oxidative methods used

Graphene, a class of two-dimensional carbon nanomaterial, has attracted extensive interest in recent years, with a significant amount of research focusing on graphene oxides (GOs). They have been primed as potential candidates for biomedical applications such as cell labeling and drug delivery, thus the toxicity and behavior of graphene oxides in biological systems are fundamental issues that need urgent attention. The production of GO is generally achieved through a top-down route, which includes the usage of concentrated H2SO4 along with: 1) concentrated nitric acid and KClO3 oxidant (Hoffmann); 2) fuming nitric acid and KClO3 oxidant (Staudenmaier); 3) concentrated phosphoric acid with KMnO4 (Tour); or 4) sodium nitrate for in-situ production of nitric acid in the presence of KMnO4 (Hummers). It has been widely assumed that the properties of these four GOs produced by using the above different methods are roughly similar, so the methods have been used interchangeably. However, several studies have reported that the toxicity of graphene-related nanomaterials in biological systems may be influenced by their physiochemical properties, such as surface functional groups and structural defects. In addition, considering how GOs are increasingly used in the field of biomedicine, we are interested to see how the oxygen content/functional groups of GOs can impact their toxicological profiles. Since in-vitro testing is a common first step in assessing the health risks related with engineered nanomaterials, the cytotoxicity of the GOs prepared by the four different oxidative treatments was investigated by measuring the mitochondrial activity in adherent lung epithelial cells (A549) by using commercially available viability assays. The dose–response data was generated by using two assays, the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and the water-soluble tetrazolium salt (WST-8). From the viability data, it is evident that there is a strong dose-dependent cytotoxic response resulting from the four GO nanomaterials tested after a 24 h exposure, and it is suggested that there is a correlation between the amounts of oxygen content/functional groups of GOs with their toxicological behavior towards the A549 cells

Nanographite impurities in carbon nanotubes : their influence on the oxidation of insulin, nitric oxide, and extracellular thiols

There has been growing interest in the use of modified-carbon-nanotube electrodes in applications such as the electrochemical detection of biologically significant compounds, owing to their apparent “electrocatalytic” properties and ability to enhance oxidative signals. In spite of their salient properties, little work has been done to further examine the reasons for these reported characteristics. In this report, we present clear evidence that the presence of nanographite impurities within carbon nanotubes (CNTs) is responsible for providing the previously reported enhanced electrochemical response. We have demonstrated this effect on homocysteine, N-acetyl-l-cysteine, nitric oxide, and insulin, which are important biological agents in the body. Moreover, we also showed that the influence of nanographite impurities on the electrochemistry of carbon nanotubes is prevalent among a variety of CNTs, such as single-walled CNTs, double-walled CNTs, and few-walled CNTs. Our findings will have a profound influence upon the biomedical applications of CNTs