Going to Where No One Went Before: Endoscopic Procedures of the Small Bowel

__Abstract__ Diagnostic and therapeutic endoscopic procedures of the small-bowel have for a long time been a great challenge to gastroenterologists. Especially the anatomy of the small intestine in combination with the lack of adequate, non-invasive, diagnostic tools, made it an almost ‘no-go’zone. Only in selected cases push enteroscopy and intraoperative enteroscopy were performed. Push enteroscopy has both diagnostic and therapeutic capabilities, but typically only examines a limited part of the proximal small bowel. Intraoperative enteroscopy permits examination of the entire small bowel and therapeutic interventions, but is much more invasive. The need for endoscopic access to improve diagnosis and treatment of small bowel disease has led to the development of novel endoscopic technologies. In 2000 the diagnostic and non-invasive video capsule endoscopy was introduced, followed by the more invasive double-balloon enteroscopy system in 2001, the latter combining diagnostic and therapeutic capabilities. The following years, single balloon enteroscopy and spiral enteroscopy were introduced as alternatives for double balloon enteroscopy, with in theory, comparable diagnostic and therapeutic capabilities. Complete enteroscopy of the small bowel is now in reach: ‘easy’ and much less invasive, and can be performed world wide in any endoscopy unit

A theoretical and experimental study of HFE-7000 in a small scale solar organic Rankine cycle as a thermofluid

The use of thermofluids with boiling temperatures lower than the water, allows the operation of low and medium temperature solar thermal systems on an Organic Rankine Cycle (ORC) to generate both mechanical and heat energy. At the same time, the selection of appropriate thermofluid is an important process and has a significant effect both on the system performance and the environment. Conventional thermofluids such as Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbons (HCFCs) have high ozone depletion (ODP) and high global warming (GWP) potential. It is therefore important to investigate novel and environmentally friendly thermofluids to address environmental impacts as global warming and ozone layer depletion. Hydrofluoroethers (HFEs) have zero ODP and relatively low GWP and therefore can be used as a replacement for CFCs and HCFCs. In this study, a small scale solar ORC is designed and commissioned to use HFE 7000 as a thermofluids. The system has a flat plate collector and a vane expander as the heat source and prime mover of the cycle respectively. The system performance is determined through energy analysis. Then, a mathematical model of the cycle is developed and the effect of various operating conditions on the components, as well as the whole cycle is examined through performing simulation analyses. Both the experimental and theoretical research indicates that HFE 7000 offers a viable alternative to be used efficiently in small scale solar ORCs to generate mechanical and heat energy

Therapeutic balloon-assisted enteroscopy

Since the introduction of the first balloon-based enteroscopic technique in 2001, therapeutic balloon-assisted enteroscopy (BAE) using either the single or double balloon enteroscopy technique (respectively SBE and DBE) has evolved rapidly. Argon plasma coagulation (APC), polypectomy, dilation therapy of strictures, and therapy of the pancreatico-biliary system in patients with surgical altered proximal intestinal anatomy: all have been successfully introduced to treat pathological findings in all segments of the small bowel. The clinical impact of treatment of vascular malformations, strictures caused by chronic inflammation (especially Crohn's disease) and polypectomy therapy (especially in the Peutz-Jeghers syndrome) seems evident. The decrease of, often repeated, surgical therapy after successful therapeutic BAE in the latter 2 patient groups appears to be a big step forward in treatment. The development of newer enteroscopes, specialized equipment and improved sedation of patients adds positively to the clinical management of undergoing therapeutic BAE. The overall complication rate of therapeutic BAE seems acceptable, but is higher compared to therapeutic colonoscopy which needs further attention in future

RENTQUAL: a new measurement scale for car rental services

Service quality perception is one of the key determinants of customer satisfaction and repeat purchase. As such, it has received considerable attention in the marketing literature. Quality issues in the car rental industry, however, have received less attention. Furthermore, there is lack of a scale developed to measure service quality in car rental services. This paper aims to develop a measurement scale in accordance with the procedure recommended by Churchill (1979) and Parasuraman, Zeithaml, and Berry (1988). Empirical studies were conducted in two waves. First, qualitative research was undertaken in the form of 23 in-depth interviews that produced 61 items describing tourists’ perceptions. Then, a quantitative study was used to purify the scale items and to examine dimensionality, reliability, factor structure and validity. Finally, an 18-item RENTQUAL scale with the following six factors emerged: comfort, delivery, safety, handing over, ergonomics and accessibility. Results show that safety is the most important factor in car rental services. Paper also presents scale development procedure, discussion, implications and limitations

Homology and symmetry breaking in Rayleigh-Benard convection: Experiments and simulations

Algebraic topology (homology) is used to analyze the weakly turbulent state of spiral defect chaos in both laboratory experiments and numerical simulations of Rayleigh-Benard convection.The analysis reveals topological asymmetries that arise when non-Boussinesq effects are present.Comment: 21 pages with 6 figure