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To address the question posed in the title, we have created, and now report details of, an open-access database of cluster structures with a web-assisted interface and toolkit as part of the WASP@N project. The database establishes a map of connectivities within each structure, the information about which is coded and kept as individual labels, called hashkeys, for the nanoclusters. These hashkeys are the basis for structure comparison within the database, and for establishing a map of connectivities between similar structures (topologies). The database is successfully used as a key element in a data-mining study of (MX)12 clusters of three binary compounds (LiI, SrO and GaAs) of which the database has no prior knowledge. The structures are assessed on the energy landscapes determined by the corresponding bulk interatomic potentials. Global optimisation, using a Lamarckian genetic algorithm, is used to search for low lying minima on the same energy landscape to confirm that the data-mined structures form a representative sample of the landscapes, with only very few structures missing from the close energy neighbourhood of the respective global minima.

We report a new class of carbon nanostructures at a lower sub-nano end of the size scale with a surprising stability, as compared to the well-known carbon fullerenes. The octahedral carbon clusters contain tetragonal rings, which, in spite of a common belief, prove to be an energy efficient means of plying graphene sheets to make three-dimensional spheroid shapes, similar to fullerenes. The two families of structures are shown to be competitive at small sizes (∼20 atoms) at room temperature, and for higher temperatures, at both small and large sizes (>200 atoms). Our calculations demonstrate that both vibrational and electronic spectra of these cluster families are similar, which thus might cloud their experimental identification. However, there is a sufficiently strong shift in vibrational frequencies below 160 and in the range of 600-800 cm -1 , which should help to identify different types of carbon clusters experimentally. We propose octahedral clusters and other structures containing tetragonal rings as viable structural elements and building units in inorganic chemistry and materials science of carbon along with fullerenes., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

We have performed a genetic algorithm search on the tight-binding interatomic potential energy surface (PES) for small TiN (N = 2-32) clusters. The low energy candidate clusters were further refined using density functional theory (DFT) calculations with the PBEsol exchange-correlation functional and evaluated with the PBEsol0 hybrid functional. The resulting clusters were analysed in terms of their structural features, growth mechanism and surface area. The results suggest a growth mechanism that is based on forming coordination centres by interpenetrating icosahedra, icositetrahedra and Frank-Kasper polyhedra. We identify centres of coordination, which act as centres of bulk nucleation in medium sized clusters and determine the morphological features of the cluster.

We have developed and implemented a new global optimization technique based on a Lamarckian genetic algorithm with the focus on structure diversity. The key process in the efficient search on a given complex energy landscape proves to be the removal of duplicates that is achieved using a topological analysis of candidate structures. The careful geometrical prescreening of newly formed structures and the introduction of new mutation move classes improve the rate of success further. The power of the developed technique, implemented in the Knowledge Led Master Code, or KLMC, is demonstrated by its ability to locate and explore a challenging double funnel landscape of a Lennard-Jones 38 atom system (LJ 38 ). We apply the redeveloped KLMC to investigate three chemically different systems: ionic semiconductor (ZnO) 1-32 , metallic Ni 13 and covalently bonded C 60 . All four systems have been systematically explored on the energy landscape defined using interatomic potentials. The new developments allowed us to successfully locate the double funnels of LJ 38 , find new local and global minima for ZnO clusters, extensively explore the Ni 13 and C 60 (the buckminsterfullerene, or buckyball) potential energy surfaces.

We present a study of the influence of the prefactor in the Arrhenius equation for the long time scale motion of defects in α-Fe. It is shown that calculated prefactors vary widely between different defect types and it is thus important to determine these accurately when implementing on-the-fly kinetic Monte Carlo (otf-KMC) simulations. The results were verified by reproducing many events using Molecular Dynamics (MD) and Temperature-Accelerated Dynamics (TAD). The calculated prefactor was shown to increase the relative interstitial-vacancy diffusion rates by an order of magnitude compared to the assumption of a constant prefactor value and the ordering of the rate table for the interstitial defect migration mechanisms was also changed. In addition, low prefactor values were observed for the 4 interstitial dumbbells configuration with low barrier transitions.

Thalidomide was recently suggested to be angiogenesis-inhibitor following the demonstration of its activity in a rabbit cornea micropocket model. The purpose of the present study was to test its efficacy in solid tumors in mice. B16-F10 melanoma and CT-26 colon carcinoma cells were injected subcutaneously, intravenously and intraperitoneally, and mice received daily gavage of 0.3-1.0 mg thalidomide starting either two or 10 days following tumor cell injection. The tumors were measured and compared with controls. There was no growth retardation in CT-26 bearing mice nor in mice with pulmonary or peritoneal metastases of B16-F10 melanoma. In 3/7 groups of mice with SC B16-F10 tumors, growth retardation was demonstrated, however the difference was not statistically significant. All tumors eventually reached maximal size, similar to controls. Morphological evaluation of the blood vessels oriented towards the tumor revealed that in both thalidomide and control groups, all mice had developed an intact network of new blood vessels. In our model for the oral administration of thalidomide inhibition of tumor growth and angiogenesis did not occur. We hypothesize that the lack of sustained antiangiogenic response was either due to immune modulation or to tumor heterogeneity and adaptation.

Simple liver cysts of various sizes are present in 1% of the population. Most are found incidentally and require no treatment. However, in a few the cyst is symptomatic and requires surgery: celiotomy and unroofing of the cyst. A 64-year-old woman with a symptomatic, simple cyst of the liver underwent laparoscopic surgery. After an uneventful course she was discharged on the 3rd postoperative day. Simple liver cysts can be safely treated by laparoscopic surgery.

The prognostic value of various subjective and objective noninvasive urological parameters was evaluated for their possible role in the prediction of post-hernioplasty urinary retention. In a prospective study, 35 patients aged 55-85 years without previous micturition complaints or urological surgery were evaluated 1 day prior to inguinal hernioplasty. This included medical history for modified Madsen subjective scoring profile, physical examination and uroflowmetry. Bladder capacity, residual urine and prostatic volume were measured by ultrasound. All patients underwent a similar method of hernioplasty, were closely followed 48 h postoperatively and any voiding difficulties or urinary retention were noted. Urinary retention occurred in 12 patients. None of the remaining 23 patients had urination difficulties. Comparing these two groups, we concluded that patient age, bladder capacity and prostatic volume have no prognostic value for potential postoperative urinary obstruction. On the other hand, obtaining a good anamnesis of obstructive and irritative symptoms for scoring, measuring maximal flow rate on urinary flowmetry and estimating residual urine volume may predict patients who are potentially at high risk for posthernioplasty urinary retention.