A comparison between nursing degree programmes offered at the University of Malta and the University of Fort Hare

Gout, a disease resulting from the effects of hyperuricemia and a crystal-induced arthropathy, may produce soft tissue masses (tophi) which mimick neoplasia clinically and radiographically. We have recently diagnosed three cases of gouty tophus, two of which were clinically suspected to represent sarcomas, by fine-needle aspiration biopsy (FNAB) after extensive radiologic and clinical evaluation. There were two women and one man. aged 71, 73, and 50 yr, with palpable soft tissue masses that involved the right forearm, right hand, and right foot, respectively, Biopsies were obtained by using 25-gauge needles without the aid of general anesthesia. Morphologically, aggregates and disassociated slender, needle-shaped crystals were abundant and easily recognized on both Diff-Quik and Papanicolaou stains. By using a polarizing microscope with a first-order red compensator, the crystals showed negative birefringence, characteristic of sodium urate. Benign-appearing histiocytes, foreign-body-type giant cells, neutrophils, and amorphous debris were scattered among the diagnostic crystals. The diagnosis of gouty tophus can be easily established with FNAB in conjunction with compensated polarizing microscopy. Application of FNAB in the initial evaluation of appropriate soft-tissue masses provides a cost-effective diagnostic method, preventing more costly and often unnecessary clinical and radiologic tests.     

Ultra electron microscopy in the SEM and STEM modes

 The approach, in this paper, to the subject of ultra electron microscopy, is based on the fundamental assumption, that the classical laws of electrodynamics and electrostatics, will apply at all levels of image formation, down to spacings which approach the electron diameter itself. The electron optical principles of ultra electron microscopy, are shown to be based on a phenomenon found in cold field-emission sources, namely, a phenomenon where the paraxial emission manifests an electron density which is orders of magnitude greater than the overall density of emission. It is argued, further, that the laws of electrodynamics and electrostatics will be valid, also, in regard to the constitution of the atom, and an example which supports that point of view, is shown. Received: 10 November 1997 / Accepted: 13 December 1997     

SuperNEC: antenna and indoor-propagation simulation program

SuperNEC is a hybrid MoM-UTD antenna and electromagnetic simulation program, developed by Poynting Software (Pty) Ltd. The UTD primitives available in the code are dielectrically coated, multi-faceted plates and elliptical cylinders. The MoM primitives supported are wire segments. The program is capable of running in parallel on a heterogeneous network of processors. A Matlab-based, interactive graphical user interface is used to define the geometry to be simulated, as well as to view the simulation results. The program has been extensively verified using a multitude of test cases, which include comparison to published results and measurements     

Electrochemical dissolution of metallic platinum in ionic liquids

The electrochemical dissolution of Pt in several ionic liquids (IL’s) was studied. Different IL’s were tested assessing their potential to dissolve Pt. Dissolution rate and current efficiency were evaluated. The main focus was on Cl containing IL’s: first generation, eutectic based IL’s and second generation IL’s with discrete anions. Pt dissolution only occurred in type 1 eutectic-based IL’s with a max. dissolution rate of 192.2 g m^?2 h^?1 and a max. current efficiency of 99 % for the ZnCl₂-1-ethyl-3-methylimidazolium chloride IL, and 9.090 g m^?2 h^?1 and 96 % for the 1:1 ZnCl₂–choline chloride ionic liquid. The dissolution occurred via the formation of [PtCl _x ] ^y? complexes. To form these complexes, addition of a metal chloride was necessary. Furthermore, an IL with an electrochemical window of 1.5 V, preferably 2.0 V is required to achieve Pt dissolution. The added metal salt needed to have a higher decomposition potential than 1.5 V or should be a Pt salt.     

Ni/Carbon Hybrid Prepared by Hydrothermal Carbonization and Thermal Treatment as Support for PtRu Nanoparticles for Direct Methanol Fuel Cell

Ni/Carbon was prepared in two steps:initially cellulose as carbon source and NiCI₂·6H20 as catalyst of the carbonization process were submitted to hydrothermal treatment at 200℃and further to thermal treatment at 900℃under argon atmosphere.The obtained material contains Ni nanoparticles with face-centered cubic （fcc） structure dispersed on amorphous carbon with graphitic domains.PtRu/C electrocatalysts（carbon-supported PtRu nanoparticles） were prepared by an alcohol-reduction process using Ni/Carbon as support.The materials were characterized by thermogravimetric analysis,energy-dispersive X-ray spectroscopy,Fourier transform infrared spectroscopy.X-ray diffraction,transmission electron microscopy and tested as anodes in single direct methanol fuel cell（DMFC）.The performances of PtRu/C electrocatalysts using Ni/Carbon as support were superior to those obtained for FtRu/C using commercial carbon black Vulcan XC72 as support.     

Distortion of DNA Origami on Graphene Imaged with Advanced TEM Techniques

While graphene may appear to be the ultimate support membrane for transmission electron microscopy (TEM) imaging of DNA nanostructures, very little is known if it poses an advantage over conventional carbon supports in terms of resolution and contrast. Microscopic investigations are carried out on DNA origami nanoplates that are supported onto freestanding graphene, using advanced TEM techniques, including a new dark‐field technique that is recently developed in our lab. TEM images of stained and unstained DNA origami are presented with high contrast on both graphene and amorphous carbon membranes. On graphene, the images of the origami plates show severe unwanted distortions, where the rectangular shape of the nanoplates is significantly distorted. From a number of comparative control experiments, it is demonstrated that neither staining agents, nor screening ions, nor the level of electron‐beam irradiation cause this distortion. Instead, it is suggested that origami nanoplates are distorted due to hydrophobic interaction of the DNA bases with graphene upon adsorption of the DNA origami nanoplates.     

A linear process-algebraic format with data for probabilistic automata

This paper presents a novel linear process-algebraic format for probabilistic automata. The key ingredient is a symbolic transformation of probabilistic process algebra terms that incorporate data into this linear format while preserving strong probabilistic bisimulation. This generalises similar techniques for traditional process algebras with data, and — more importantly — treats data and data-dependent probabilistic choice in a fully symbolic manner, leading to the symbolic analysis of parameterised probabilistic systems. We discuss several reduction techniques that can easily be applied to our models. A validation of our approach on two benchmark leader election protocols shows reductions of more than an order of magnitude.