Successful repair of mega aorta using reversed elephant trunk procedure

AbstractThe case reported is of a patient with mega aorta and a symptomatic thoracoabdominal aortic segment. Successful treatment involved resection and graft replacement of the thoracoabdominal segment as an initial procedure using a “reversed elephant trunk” technique, followed by resection and replacement of the ascending aorta and transverse aortic arch as the second stage. (J Vasc Surg 1998;27:183-8.

Mechanical strength of aneurysmatic and dissected human thoracic aortas at different shear loading modes

Rupture of aneurysms and acute dissection of the thoracic aorta are life-threatening events which affect tens of thousands of people per year. The underlying mechanisms remain unclear and the aortic wall is known to lose its structural integrity, which in turn affects its mechanical response to the loading conditions. Hence, research on such aortic diseases is an important area in biomechanics. The present study investigates the mechanical properties of aneurysmatic and dissected human thoracic aortas via triaxial shear and uniaxial tensile testing with a focus on the former. In particular, ultimate stress values from triaxial shear tests in different orientations regarding the aorta's orthotropic microstructure, and from uniaxial tensile tests in radial, circumferential and longitudinal directions were determined. In total, 16 human thoracic aortas were investigated from which it is evident that the aortic media has much stronger resistance to rupture under ‘out-of-plane’ than under ‘in-plane’ shear loadings. Under different shear loadings the aortic tissues revealed anisotropic failure properties with higher ultimate shear stresses and amounts of shear in the longitudinal than in the circumferential direction. Furthermore, the aortic media decreased its tensile strength as follows: circumferential direction > longitudinal direction > radial direction. Anisotropic and nonlinear tissue properties are apparent from the experimental data. The results clearly showed interspecimen differences influenced by the anamnesis of the donors such as aortic diseases or connective tissue disorders, e.g., dissected specimens exhibited on average a markedly lower mechanical strength than aneurysmatic specimens. The rupture data based on the combination of triaxial shear and uniaxial extension testing are unique and build a good basis for developing a 3D failure criterion of diseased human thoracic aortic media. This is a step forward to more realistic modeling of mechanically induced tissue failure i.e. rupture of aneurysms or progression of aortic dissections

Acute respiratory infection in patients with cystic fibrosis with mild pulmonary impairment: Comparison of two physiotherapy regimens

Chest physiotherapy is an essential part of the management of cystic fibrosis, yet comparatively few studies have investigated the commonly used forms of chest physiotherapy during acute respiratory exacerbations. Fifteen subjects with cystic fibrosis and predominantly mild pulmonary impairment completed a randomised cross-over trial with 24 hours between treatments. The active cycle of breathing techniques (ACBT) assisted by a physiotherapist was compared with the ACBT performed independently by the patient. Measurement outcomes included pulmonary function tests, indirect calorimetry and oximetry parameters. Energy expenditure was not significantly different between the two treatment regimens, though significant improvements in pulmonary function were apparent 24 hours following the therapist-assisted ACBT. In this group of subjects, neither form of treatment proved superior in terms of energy consumption, but a reduction in airways obstruction was observed as a carry-over effect following the therapist-assisted ACBT.Marie T Williams, David W Parsons , Ross A Frick, Elizabeth R Ellis, A James Martin, Sally E Giles and E Ruth Gran

Diploids in the Cryptococcus neoformans Serotype A Population Homozygous for the α Mating Type Originate via Unisexual Mating

The ubiquitous environmental human pathogen Cryptococcus neoformans is traditionally considered a haploid fungus with a bipolar mating system. In nature, the α mating type is overwhelmingly predominant over a. How genetic diversity is generated and maintained by this heterothallic fungus in a largely unisexual α population is unclear. Recently it was discovered that C. neoformans can undergo same-sex mating under laboratory conditions generating both diploid intermediates and haploid recombinant progeny. Same-sex mating (α-α) also occurs in nature as evidenced by the existence of natural diploid αADα hybrids that arose by fusion between two α cells of different serotypes (A and D). How significantly this novel sexual style contributes to genetic diversity of the Cryptococcus population was unknown. In this study, ∼500 natural C. neoformans isolates were tested for ploidy and close to 8% were found to be diploid by fluorescence flow cytometry analysis. The majority of these diploids were serotype A isolates with two copies of the α MAT locus allele. Among those, several are intra-varietal allodiploid hybrids produced by fusion of two genetically distinct α cells through same-sex mating. The majority, however, are autodiploids that harbor two seemingly identical copies of the genome and arose via either endoreplication or clonal mating. The diploids identified were isolated from different geographic locations and varied genotypically and phenotypically, indicating independent non-clonal origins. The present study demonstrates that unisexual mating produces diploid isolates of C. neoformans in nature, giving rise to populations of hybrids and mixed ploidy. Our findings underscore the importance of same-sex mating in shaping the current population structure of this important human pathogenic fungus, with implications for mechanisms of selfing and inbreeding in other microbial pathogens

Human studies of anorectal sensory function.

This review addresses three main questions: (1) Why is anorectal sensory function important in humans? (2) What is the evidence for anorectal sensory dysfunction in disease? (3) Can anorectal sensory function be modified for therapeutic benefit

Continence and micturition : an anatomical basis

Urinary incontinence remains an important clinical problem worldwide, having a significant socio-economic, psychological, and medical burden. Maintaining urinary continence and coordinating micturition are complex processes relying on interaction between somatic and visceral elements, moderated by learned behavior. Urinary viscera and pelvic floor must interact with higher centers to ensure a functionally competent system. This article aims to describe the relevant anatomy and neuronal pathways involved in the maintenance of urinary continence and micturition. Review of relevant literature focusing on pelvic floor and urinary sphincters anatomy, and neuroanatomy of urinary continence and micturition. Data obtained from both live and cadaveric human studies are included. The stretch during bladder filling is believed to cause release of urothelial chemical mediators, which in turn activates afferent nerves and myofibroblasts in the muscosal and submucosal layers respectively, thereby relaying sensation of bladder fullness. The internal urethral sphincter is continuous with detrusor muscle, but its arrangement is variable. The external urethral sphincter blends with fibers of levator ani muscle. Executive decisions about micturition in humans rely on a complex mechanism involving communication between several cerebral centers and primitive sacral spinal reflexes. The pudendal nerve is most commonly damaged in females at the level of sacrospinous ligament. We describe the pelvic anatomy and relevant neuroanatomy involved in maintaining urinary continence and during micturition, subsequently highlighting the anatomical basis of urinary incontinence. Comprehensive anatomical understanding is vital for appropriate medical and surgical management of affected patients, and helps guide development of future therapies. Clin. Anat., 2014. © 2014 Wiley Periodicals, Inc

Impact of user behavior assumptions on computed urban scale building energy use

Mit Hilfe von thermischer Gebäudesimulation können heute verschiedene Key Performance Indikatoren relativ mühelos mit einem hohen Grad an Genauigkeit ermittelt werden. In üblichen Simulationswerkzeugen wird das Nutzer*innenverhalten zumindest rudimentär beschrieben. Nichtsdestotrotz muss festgehalten werden, dass eine genaue Abbildung der Interaktion von Nutzer*innen mit dem Gebäude als Aufenthaltsort und als Aggregat von die Gebäudeperformance beeinflussenden Systemen nach wie vor als eine der größten Herausforderungen in der Domäne Gebäudesimulation gilt. Das hat mitunter mit der sehr diversen Struktur des Nutzer*innenverhaltens betreffend Anwesenheit in zeitlicher und räumlicher Dimension, wie auch mit der Interaktion der Nutzer*innen mit verschiedenen Teilsystemen des Systems Gebäude, wie Heizungssysteme, Verschattung und Lüftung und der damit verbundenen Implikationen auf die verschiedenen Teilaspekte, welche die (thermische) Gebäudeperformance beeinflussen. In verschiedenen wissenschaftlichen Studien wurden historische, durch Beobachtung oder Messung erlangte Werte als geeignet zum Einsatz in den Simulationen verwendet. Dies ist jedoch offensichtlich mit einem großen Aufwand betreffend Datensammlung und entsprechender Bearbeitung (Stukturierung, Skalierung, etc.) verbunden. In dieser Masterthese werden unterschiedliche Szenarien der Nutzer*innen Interaktion („Occupancy“) mit Gebäuden untersucht. Die übergeordnete Zielsetzung ist es, ein besseres Verständnis für den Einfluss des Nutzer*Innenverhaltens auf die Gebäudeperformance zu erlangen. Um dies großmaßstäblich studieren zu können, wurde ein Gebäudesample aus Wien gewählt, welches basierend auf Aspekten wie Volumen, Größe, Nutzung und Alter geeignet ist, die Gebäudestruktur eines Wiener Bezirksteils zu repräsentieren. Da eine genaue simulationsbezogene Analyse des gesamten Gebäudebestands auf Grund des damit verbundenen enormen Aufwands kaum sinnvoll durchführbar ist, dient dieses Sample zur Detailuntersuchung. Auf das Gebäudesample werden unterschiedliche Occupancy-Szenarien angewandt und diese dann mittels thermischer Gebäudesimulation hinsichtlich ihres Einflusses auf KPIs untersucht.Die Ergebnisse aus dem Gebäudesample werden dann mittels statistischer Methoden auf den Bezirk übertragen („Upscaling“). Damit kann ermittelt werden, mit welchem Einsparungspotentialen hinsichtlich einer Veränderung des Nutzer*innenverhaltens gerechnet werden kann.Building performance simulation software tools deliver various key performance indicators of different aspects of building performance. To a certain extent such tools integrate occupant behaviour input data. However, an accurate mapping of real user behaviour in form of human interaction with the building and its systems into simulation models can be considered as challenging. This is due to the diverse nature of user behaviour regarding occupancy, time dimension, and impact on the different aspects of the building performance. Several studies suggest the integration of available historical and measured data as input data for simulation. Needless to say, this approach is connected with the strenuous effort of collecting and structuring such data.In this contribution, reasonable scenarios of occupant’s interaction with buildings are studied. Thereby, the major aim is to gain a better understanding of the impact of occupant behaviour onto the building’s performance. For this purpose, a sample of buildings, which have been chosen to represent the building stock in the central area of Vienna, Austria, is subjected to building performance simulation with different assumptions regarding the occupancy behaviour. These different assumptions lead to different results in view of building performance KPIs. As such, the impact of different occupancy assumptions onto buildings that vary in size, usage, and thermal envelope quality is extensively studied.The results obtained for these sample buildings include heating loads, cooling loads, and the temperature conditions including potential occurrences of overheating. An extensive comparison of the different buildings with associated occupant population patterns is undertaken. These interim results are then upscaled to the overall building stock via methods of statistics. As a result, the described efforts allow for a qualified estimation of potential of the behavioural changes in reducing building-related energy use.11