SLM Materials Development

The purpose of this project was to create a procedure to efficiently determine a “recipe” of parameter values that create a desired set of mechanical properties. Research was conducted into the laser powder bed fusion process with focus on underdeveloped materials. A design of experiment was used with a set of density correlated parameters to establish a method of producing nearly dense parts. Our methods include SLM printing, metrology, and statistical analysis. An experimental procedure for materials development was designed, but unable to be validated during the scope of this project, due to unforeseen safety issues (exposure to Chromium 6, a toxic substance). Next steps include validation of this procedure using various metal powders in a SLM 125 HL

Notes concerning the semi-terrestrial and freshwater amphipods (Crustacea : Peracarida) of the Maltese Islands

Interest in Mediterranean amphipods has been re-focused recently by the appearance of a new multi-author monograph on the group edited by Professor Sandro Ruffo (1982 and continuing) which, when complete, will replace the classic work of Chevreux & Fage (1925). In spite of this progress, however, wide areas of the Mediterranean are still almost unknown amphipodologically (Ruffo (ed.), 1982) and detailed fauna lists are wanting for many regions. For the past few years, one of us (P.I.S.) has been surveying bodies of freshwater in the Maltese Islands and samples have now been amassed from all the main fresh- and brackish water sites in the islands. Since just about every body of freshwater dries up early in the summer (and remains so for the best part of six months each year) it is interesting to see just how many amphipod species the islands' freshwaters support. Since present knowledge of Maltese semi-terrestrial amphipods is also limited they too have been included in our surveys. The following list summarizes our taxonomic (P.G.M.) and ecological (P.I.S.) knowledge of the Amphipoda from these habitats on the Maltese Islands. All material is deposited in the personal collections of P.I.S. with the exception of Allorchestes aquilinus (A. Costa) which is in the collections of P.G.M.peer-reviewe

Vaccination approaches for the prevention of urinary tract infection

Urinary tract infections (UTIs) are one of the most common infectious diseases of humans, with approximately 150 million cases estimated to occur globally every year. UTIs usually start as a bladder infection (cystitis), but can develop into acute kidney infection (pyelonephritis) and even infection of the bloodstream (urosepsis). The high frequency of UTIs in community and nosocomial settings places an enormous burden on healthcare systems worldwide. Multiple different pathogens cause UTI, with uropathogenic E. coli (UPEC) the most common etiological agent. UTIs caused by these pathogens are increasingly associated with antibiotic resistance, thus severely reducing treatment options and significantly increasing UTI-associated morbidity and mortality. In this review we present an overview of the recent advances in vaccine research targeted towards the prevention of UPEC-mediated UTI. In the context of multidrug resistance, we conclude that vaccination represents a viable approach for the prevention of chronic and recurrent UTI

Detection of the United States Neisseria meningitidis urethritis clade in the United Kingdom, August and December 2019 - emergence of multiple antibiotic resistance calls for vigilance.

Since 2015 in the United States (US), the US Neisseria meningitidis urethritis clade (US_NmUC) has caused a large multistate outbreak of urethritis among heterosexual males. Its 'parent' strain caused numerous outbreaks of invasive meningococcal disease among men who have sex with men in Europe and North America. We highlight the arrival and dissemination of US_NmUC in the United Kingdom and the emergence of multiple antibiotic resistance. Surveillance systems should be developed that include anogenital meningococci

The mutual relationship between heart failure and atrial fibrillation

Atrial fibrillation (AF) and Heart Failure (HF) are evolving epidemies, together responsible for substantial human suffering and health-care expenditure. The simultaneous co-existence of the two conditions is associated with higher mortality rates than those observed in individuals with only one or none of them. Patients with concomitant HF and AF suffer from even worse symptoms and poorer prognosis, yet evidence-based evaluation and management of this group of patients is lacking. In this review, we evaluate the common mechanisms for the development of AF in HF patients and vice versa, focusing on the evidence for potential treatment strategies. Recent data have suggested that these patients may respond differently if compared to those with HF or AF alone. These results highlight the clear clinical need to identify and treat these diseases according to best evidence, in order to prevent adverse outcomes and reduce the huge burden er that HF and AF are expected to have on global healthcare systems in the future

Diversity of group B streptococcus serotypes causing urinary tract infection in adults

Serotypes of group B streptococcus (GBS) that cause urinary tract infection (UTI) are poorly characterized. We conducted a prospective study of GBS UTI in adults to define the clinical and microbiological characteristics of these infections, including which serotypes cause disease. Patients who had GBS cultured from urine over a 1-year period were grouped according to symptoms, bacteriuria, and urinalysis. Demographic data were obtained by reviewing medical records. Isolates were serotyped by latex agglutination and multiplex PCRreverse line blotting (mPCR/RLB). Antibiotic susceptibilities were determined by disc diffusion. GBS was cultured from 387/34,367 consecutive urine samples (1.1%): 62 patients had bacteriuria of >10 7 CFU/liter and at least one UTI symptom; of these patients, 31 had urinary leukocyte esterase and pyuria (others not tested), 50 (81%) had symptoms consistent with cystitis, and 12 (19%) had symptoms of pyelonephritis. Compared with controls (who had GBS isolated without symptoms), a prior history of UTI was an independent risk factor for disease. Increased age was also significantly associated with acute infection. Serotyping results were consistent between latex agglutination and mPCR/RLB for 331/387 (85.5%) isolates; 22 (5.7%) and 7 (1.8%) isolates were nontypeable with antisera and by mPCR/RLB, respectively; and 45/56 (80.4%) isolates with discrepant results were typed by mPCR/RLB as belonging to serotype V. Serotypes V, Ia, and III caused the most UTIs; serotypes II, Ib, and IV were less common. Nontypeable GBS was not associated with UTI. Erythromycin (39.5%) and clindamycin (26.4%) resistance was common. We conclude that a more diverse spectrum of GBS serotypes causes UTI than previously recognized, with the exception of nontypeable GBS

Differences in demersal community structure and biomass size spectra within and outside the Maltese Fishery Management Zone (FMZ)

We examined the protection effect of a long-established fisheries protection zone by studying the demersal communities and the biomass size spectra of specific taxonomic groups. The results and the relevant management implications of the community analysis are discussed within the context of the MEDITS trawl survey program, from which the data was derived. The demersal fishery resources on the muddy bottoms of Maltese trawling grounds were found to be stratified in four main depth ranges: 83 to 166 m (outer continental shelf), 140 to 230 m (shelf break), 270 to 440 m (shallow slope), and 466 to 701 m (deep slope). Significant differences were detected between the inside and outside zones of the outer continental shelf. Stations from this stratum inside the protected zone had twice as much biomass as those outside as well as larger individuals of some species (e.g. elasmobranchs). The depth strata identified do not coincide with those sampled in existing trawl survey programmes in the Sicilian Channel, which were set up without reference to demersal assemblage structure and its relation to depth. It is therefore clear that characterisation of the biotic assemblages is important in order to obtain a better sampling representation of each depth-stratum/assemblage type, and this should be considered in the survey design.peer-reviewe

The influence of pH, temperature and salt on the ethanolic desolvation of dilute cold water fish skin gelatin from aqueous solution

Gelatin is a heterogeneous mixture of water-soluble proteins of high molecular weight. It is the degradation product of the protein collagen, a long triple-stranded helical rod which is stabilized by non-covalent interactions and covalent crosslinking. A number of studies have been carried on the desolvation of various types of gelatin of mammalian origin.1,2 Cold-water fish skin gelatin (CWFSG) has a different imino acid composition to mammalian gelatin. The number of proline and hydroxylproline groups in CWFSG is lower and this means that there is less hydrogen bonding. This leads to a different secondary structure. Moreover, the differences in the primary structure of the protein would also be expected to cause differences in other physical properties fish gelatin may exhibit. The objective of this work was to determine the response of CWFSG in aqueous solution, to the non- solvent ethanol under different conditions of pH, temperature and concentration.peer-reviewe

Uropathogenic Escherichia coli virulence and innate immune responses during urinary tract infection

Urinary tract infections (UTI) are among the most common infectious diseases of humans and are the most common nosocomial infections in the developed world. It is estimated that 40-50% of women and 5% of men will develop a UTI in their lifetime, and UTI accounts for more than 1 million hospitalizations and $1.6 billion in medical expenses each year in the USA. Uropathogenic Escherichia coli (UPEC) is the primary cause of UTI. This review presents an overview of recent discoveries related to the primary virulence factors of UPEC and major innate immune responses to infection of the lower urinary tract. New and emerging themes in UPEC research are discussed in the context of the interface between host and pathogen