Exploring radiographers' experience with mobile X-ray of patients in their homes.

INTRODUCTION: To offer citizens with frailty or dementia living in nursing homes or other institutions a less stressful and anxious X-ray examination, a Danish hospital offers to perform the examination in the citizen's residence. This has changed the working procedure for the radiographers performing the examination. The aim of this study was to explore if the radiographers self-perceived competencies have changed whilst working in the mobile X-ray unit and if so, how these competencies are utilised within the department-based medical imaging team. METHOD: This study had a qualitative design following a hermeneutic approach. Individual semi structured interviews included nine radiographers, four radiographers working in the mobile X-ray unit and five radiographers working exclusively in the medical imaging team. RESULTS: Radiographers who worked in the mobile X-ray unit did acquire new competencies such as better communication and creative positioning skills. All nine participants recognised the advantage of sharing experiences and competencies with colleagues, and recommended a formal forum to do so. They sought opportunities for the use of the mobile X-ray unit to be more widespread within their own region, and within the profession. CONCLUSION: This study indicates that radiographers working with mobile X-ray unit gained new competencies in communication and positioning, but without spread of new knowledge to colleagues in the medical imaging team. IMPLICATION FOR PRACTICE: The use of home-based mobile X-ray is a new way to provide health care services and gain new competencies for the radiographers to focus on patient centred care.

Towards low-dimensional hole systems in Be-doped GaAs nanowires.

GaAs was central to the development of quantum devices but is rarely used for nanowire-based quantum devices with InAs, InSb and SiGe instead taking the leading role. p-type GaAs nanowires offer a path to studying strongly confined 0D and 1D hole systems with strong spin-orbit effects, motivating our development of nanowire transistors featuring Be-doped p-type GaAs nanowires, AuBe alloy contacts and patterned local gate electrodes towards making nanowire-based quantum hole devices. We report on nanowire transistors with traditional substrate back-gates and EBL-defined metal/oxide top-gates produced using GaAs nanowires with three different Be-doping densities and various AuBe contact processing recipes. We show that contact annealing only brings small improvements for the moderately doped devices under conditions of lower anneal temperature and short anneal time. We only obtain good transistor performance for moderate doping, with conduction freezing out at low temperature for lowly doped nanowires and inability to reach a clear off-state under gating for the highly doped nanowires. Our best devices give on-state conductivity 95 nS, off-state conductivity 2 pS, on-off ratio [Formula: see text], and sub-threshold slope 50 mV/dec at [Formula: see text] K. Lastly, we made a device featuring a moderately doped nanowire with annealed contacts and multiple top-gates. Top-gate sweeps show a plateau in the sub-threshold region that is reproducible in separate cool-downs and indicative of possible conductance quantisation highlighting the potential for future quantum device studies in this material system.

Large animal models of atherosclerosis--new tools for persistent problems in cardiovascular medicine.

Coronary heart disease and ischaemic stroke caused by atherosclerosis are leading causes of illness and death worldwide. Small animal models have provided insight into the fundamental mechanisms driving early atherosclerosis, but it is increasingly clear that new strategies and research tools are needed to translate these discoveries into improved prevention and treatment of symptomatic atherosclerosis in humans. Key challenges include better understanding of processes in late atherosclerosis, factors affecting atherosclerosis in the coronary bed, and the development of reliable imaging biomarker tools for risk stratification and monitoring of drug effects in humans. Efficient large animal models of atherosclerosis may help tackle these problems. Recent years have seen tremendous advances in gene-editing tools for large animals. This has made it possible to create gene-modified minipigs that develop atherosclerosis with many similarities to humans in terms of predilection for lesion sites and histopathology. Together with existing porcine models of atherosclerosis that are based on spontaneous mutations or severe diabetes, such models open new avenues for translational research in atherosclerosis. In this review, we discuss the merits of different animal models of atherosclerosis and give examples of important research problems where porcine models could prove pivotal for progress.

Kondo-enhanced Andreev tunneling in InAs nanowire quantum dots.

We report measurements of the nonlinear conductance of InAs nanowire quantum dots coupled to superconducting leads. We observe a clear alternation between odd and even occupation of the dot, with subgap peaks at |V(sd)| = Delta/e markedly stronger (weaker) than the quasiparticle tunneling peaks at |V(sd)| = 2Delta/e for odd (even) occupation. We attribute the enhanced Delta peak to an interplay between Kondo correlations and Andreev tunneling in dots with an odd number of spins, and we substantiate this interpretation by a poor man's scaling analysis.

[Keratin diseases]. / Keratinsygdomme.

The rapid development in human genome research has resulted in a tremendous increase in our understanding of the molecular basis of many genetic skin diseases. One outstanding example of this is diseases caused by mutations in keratin genes, which comprise several disorders of the epidermis, as for example the different types of epidermolysis bullosa simplex. In this respect, the most important questions have been to 1. Define the molecular defect. 2. Unravel the pathophysiological mechanisms that lead to the characteristic phenotype and 3. Design of new therapeutic strategies. Molecular research has contributed significantly to the first two issues whereas a therapeutic break-through has yet to appear.

[Epidermolysis bullosa simplex: genotype-phenotype correlation in Danish patients]. / Epidermolysis bullosa simplex: korrelation mellem genotype og faenotype hos danske patienter.

Epidermolysis bullosa simplex (EBS) is a group of autosomal dominant inherited skin disorders caused by mutations in the keratin genes K5 or K14. We examined five Danish families with EBS-Weber-Cockayne (WC) or EBS-Koebner (K) and two sporadic cases of EBS-Dowling-Meara (DM) in order to investigate the mutational spectrum and evaluate the genotype-phenotype correlation in Danish patients. Three new K14 mutations, one new and one previously described K5 mutation were identified by DNA sequence analysis. The positions of the EBS-DM mutations were consistent with previous studies, whereas the EBS-WC and EBS-K mutations were found in regions of the keratin genes not typically associated with this type of EBS mutations. In conclusion, we found a strict genotype-phenotype correlation. Furthermore, we found that the position of the mutation in the keratin gene is not the only determinant for severity of the disease; the nature of the amino acid substitution should also be considered when predicting the severity of the EBS disorder.

Identification of novel and known mutations in the genes for keratin 5 and 14 in Danish patients with epidermolysis bullosa simplex: correlation between genotype and phenotype.

Epidermolysis bullosa simplex (EBS) is a group of autosomal dominant inherited skin diseases caused by mutations in either the keratin 5 (K5) or the keratin 14 (K14) genes and characterized by development of intraepidermal skin blisters. The three major subtypes of EBS are Weber-Cockayne, Koebner, and Dowling-Meara, of which the Dowling-Meara form is the most severe. We have investigated five large Danish families with EBS and two sporadic patients with the Dowling-Meara form of EBS. In the sporadic Dowling-Meara EBS patients, a novel K14 mutation (N123S) and a previously published K5 mutation (N176S) were identified, respectively. A novel K14 mutation (K116N) was found in three seemingly unrelated families, whereas another family harbored a different novel K14 mutation (L143P). The last family harbored a novel K5 mutation (L325P). The identified mutations were not present in more than 100 normal chromosomes. Six polymorphisms were identified in the K14 gene and their frequencies were determined in normal controls. These polymorphisms were used to show that the K14 K116N mutation was located in chromosomes with the same haplotype in all three families, suggesting a common ancestor. We observed a strict genotype-phenotype correlation in the investigated patients as the same mutation always resulted in a similar phenotype in all individuals with the mutation, but our results also show that it is not possible to predict the EBS phenotype merely by the location (i.e., head, rod, or linker domains) of a mutation. The nature of the amino acid substitution must also be taken into account.

Cloning of the murine tetranectin gene and 5'-flanking region.

The gene encoding murine tetranectin (Tna) and its 5'-flanking region was isolated and cloned from a EMBL3 SP6/T7 genomic library. The compiled nucleotide sequence was determined by sequencing, revealing a conserved Tna structure in man and mouse. Mapping of the transcription start point (tsp) suggests that murine Tna has more than one of these. In addition, no consensus TATA-box was found uptream for the putative tsp(s) in the 5'-flanking region of the gene, indicating that the murine Tna promoter belongs to the TATA-less class of genes. The cloned murine Tna was mapped to region F1-F3 on mouse chromosome 9 by fluorescence in situ hybridization (FISH).

Cloning of a cDNA encoding murine tetranectin.

A full-length cDNA encoding murine tetranectin (TN) was isolated and cloned from a murine lung lambda ZAPII cDNA library. The complete nucleotide sequence was determined revealing an open reading frame encoding 202 amino acids (aa) including a signal peptide of 21 aa. An overall aa identity of 79% exists between the deduced aa sequences of human and murine TN, revealing a high evolutionary conservation of the protein. The highest expression of mouse TN was found in lung and skeletal muscle.

Determination of the disulphide bridge arrangement of bovine histidine-rich glycoprotein.

Histidine-rich glycoprotein (HRG) was purified from bovine plasma and the disulphide bridge arrangement established. Disulphide-bridged peptides were obtained from peptic and tryptic degradation of native bovine HRG. Twelve half-cystine residues were found in bovine HRG (compared to sixteen cysteines in human HRG), all involved in the formation of six disulphide bridges connecting Cys-1 to Cys-12, Cys-2 to Cys-3, Cys-4 to Cys-5, Cys-6 to Cys-11, Cys-7 to Cys-8, and Cys-9 to Cys-10. Additional sequence analysis of 14C-carboxymethylated chymotryptic and Staphylococcus aureus V8 protease generated peptides and CNBr-fragments of bovine HRG yielded a partial amino acid sequence of bovine HRG constituting 78% of the sequence when compared to the human cDNA sequence.