27 research outputs found
Histopathology of aortic complications in bicuspid aortic valve versus Marfan syndrome: relevance for therapy?
Patients with bicuspid aortic valve (BAV) and patients with Marfan syndrome (MFS) are more prone to develop aortic dilation and dissection compared to persons with a tricuspid aortic valve (TAV). To elucidate potential common and distinct pathways of clinical relevance, we compared the histopathological substrates of aortopathy. Ascending aortic wall biopsies were divided in five groups: BAV (n = 36) and TAV (n = 23) without and with dilation and non-dilated MFS (n = 8). General histologic features, apoptosis, the expr
Effects of thermoregulation on human sleep patterns: A mathematical model of sleep-wake cycles with REM-NREM subcircuit
In this paper we construct a mathematical model of human sleep/wake regulation with thermoregulation and temperature e ects. Simulations of this model show features previously presented in experimental data such as elongation of duration and number of REM bouts across the night as well as the appearance of awakenings due to deviations in body temperature from thermoneutrality. This model helps to demonstrate the importance of temperature in the sleep cycle. Further modi cations of the model to include more temperature e ects on other aspects of sleep regulation such as sleep and REM latency are discussedPostprint (author's final draft
Skin hardening effect in patients with polymorphic light eruption: Comparison of UVB hardening in hospital with a novel home UV-hardening device
Backgroundâ An effective prophylactic treatment of patients with polymorphic light eruption (PLE) consists of repeated low, gradually increasing exposures to UVB radiation. This so-called UV(B) hardening induces better tolerance of the skin to sunlight. Objectiveâ SunshowerMedical company (Amsterdam) has developed an UV (B) source that can be used during taking shower. The low UV fluence of this apparatus makes it an interesting device for UV hardening. In a group of PLE patients, we compared the effectiveness of the irradiation with SunshowerMedical at home with that of the UVB treatment in the hospital. Methodsâ The PLE patients were randomized for one of the treatments. The hospital treatment consisted of irradiations with broad-band UVB (Waldmann 85/UV21 lamps) twice a week during 6âweeks. The home UV-device was used each day with the maximal irradiation time of 6âmin. The outcome assessment was based on the information obtained from patients' dermatological quality of life (DLQI) questionnaires, the ability of both phototherapies to reduce the provocation reaction and from the patients' evaluation of the long-term benefits of their phototherapies. Resultsâ Sixteen patients completed treatment with SunshowerMedical and thirteen completed treatment in hospital. Both types of phototherapy were effective. There was a highly significant improvement in DLQI with either treatment. In most cases, the hardening reduced or even completely suppressed clinical UV provocation of PLE. The patients using SunshowerMedical at home were, however, much more content with the treatment procedure than the patients visiting the dermatological units. Conclusionsâ Both treatments were equally effective in the induction of skin tolerance to sunlight in PLE patients. However, the home treatment was much better accepted than the treatment in the hospital.Dermatology and Venereolog
The Economics of Agricultural Supply Chain Design: A Portfolio Selection Approach
Agrifood firms in the modernizing/globalizing world, both in developing and developed countries,
regularly need to undertake innovations. They develop supply chains to accommodate
the nature of the innovations. In this paper we analyze an innovatorâs supply chain design
problem. The design of the supply chain may include allocating resources between production
of feedstock (agricultural products) and processing and marketing, and determining
the amount of feedstock to be obtained through contracts. We show that the innovator
determines its overall level of production taking advantage of its monopoly power in the
output market, and behaves as a monopsony in buying feedstock from contractors. These
decisions are constrained by the marginal cost of capital and the properties of production
and marketing technologies. When the innovator is risk averse, risk considerations in production
processing and marketing and the correlation between risks will affect both overall
production and share of input purchased through contracts