3,335 research outputs found
The development of a resource-efficient photovoltaic system
This paper presents the measures taken in the demonstration of the photovoltaic case study developed within the European project ‘Towards zero waste in industrial networks’ (Zerowin), integrating the D4R (Design for recycling, repair, refurbishment and reuse) criteria at both system and industrial network level. The demonstration is divided into three phases. The first phase concerns the development of a D4R photovoltaic concept, the second phase focused on the development of a specific component of photovoltaic systems and the third phase was the demonstration of the D4R design in two complete photovoltaic systems (grid-connected and stand-alone). This paper includes a description of the installed photovoltaic systems, including a brief summary at component level of the lithium ion battery system and the D4R power conditioning system developed for the pilot installations. Additionally, industrial symbioses within the network associated with the photovoltaic systems and the production model for the network are described
Overruled!: Implicit cues rather than an orthographic rule determine Dutch children's vowel spelling
Therapeutic Drug-Monitoring of Methotrexate-Polyglutamates in Rheumatoid Arthritis
__Abstract__
Rheumatoid Arthritis (RA) is a chronic autoimmune disease, characterized by the swelling
of joints, uncontrolled proliferation of synovial tissue and multisystem co-morbidities. RA
mainly affects the joints of the hands, feet, knees, wrist and elbows, with joint damage
occurring early in the disease course. RA affects an estimated 1% of the general population
and women have a higher risk of developing RA than men. Despite the fact that treatment
strategy has changed considerably over the years, reflected by a much improved disease
outcome, there is still no cure for RA.
Early initiation of therapy is effective in prevention of joint damage and results in
milder medication regimes while maintaining disease remission. Early in the disease,
the inflammation is less self-perpetuating and easier to suppress, therefore it is important
to start treatment as early as possible in order to optimize outcome, minimize medical costs,
improve quality of life, and improve medical decision making
NG-nitro L-arginine methyl ester: systemic and pulmonary haemodynamics, tissue blood flow and arteriovenous shunting in the pig
The effects of NG-nitro-Lrarginine methyl ester (L-NAME), an inhibitor of the endothelial nitric oxide (NO) biosynthesis, on systemic and pulmonary haemodynamics, and tissue as well as arteriovenous anastomotic blood flows were investigated in the anaesthetized pig, using simultaneous injections of radioactive microspheres of two different sizes (diameter: 15 and 50μm). L-NAME (1, 3 and 10 mg·kg-1) reduced systemic and pulmonary artery conductance and cardiac output, but heart rate and mean arterial blood pressure remained unchanged. L-arginine reversed the systemic and pulmonary haemodynamic changes induced by L-NAME. As detected with 15 μm microspheres, L-NAME (1 and 3 mg·kg-1) decreased tissue blood flow to and vascular conductance in the eyes, lungs, atria, kidneys, adrenals and liver. Furthermore, the difference between blood flows simultaneously measured with 15 and 50 μm microspheres, which can be equated to blood flow through arteriovenous anastomoses with a diameter between about 28 and 90 μm, was reduced by L-NAME (3 mg · kg-1) in the skin of head and gluteal regions and, as indicated by the microsphere content of the lungs, in the total systemic circulation. These results suggest that in the anaesthetized pig (i) NO is involved in the regulation of both systemic and pulmonary vascular conductance, (ii) the decrease in systemic vascular conductance is in part due to constriction of systemic arteriovenous anastomoses, and (iii) the decrease in pulmonary vascular conductance, leading to reduction of cardiac output, seems to negate the expected rise in arterial blood pressure observed, for example, in rats and rabbits following inhibition of NO-synthesis
Recruitment of bone marrow derived cells during anti-angiogenic therapy in GBM:The potential of combination strategies
Glioblastoma (GBM) is a highly vascular tumor characterized by rapid and invasive tumor growth, followed by oxygen depletion, hypoxia and neovascularization, which generate a network of disorganized, tortuous and permeable vessels. Recruitment of bone marrow derived cells (BMDC) is crucial for vasculogenesis. These dells may act as vascular progenitors by integrating into the newly formed blood vessels or as vascular modulators by releasing pro-angiogenic factors. In patients with recurrent GBM, anti-vascular endothelial growth factor (VEGF) therapy has been evaluated in combination with chemotherapy, yielding improvements in progression-free survival (PFS). However, benefits are temporary as vascular tumors acquire angiogenic pathways independently of VEGF. Specifically, acute hypoxia following prolonged VEGF depletion induces the recruitment of certain myeloid cell subpopulations, which highly contribute to treatment refractoriness. Here we review the molecular mechanisms of neovascularization in relation to bevacizumab therapy with special emphasis on the recruitment of BMDCs and possible combination therapies for GBM patients. (C) 2014 Elsevier Ireland Ltd. All rights reserved
Social welfare and profit maximization from revealed preferences
Consider the seller's problem of finding optimal prices for her
(divisible) goods when faced with a set of consumers, given that she can
only observe their purchased bundles at posted prices, i.e., revealed
preferences. We study both social welfare and profit maximization with revealed
preferences. Although social welfare maximization is a seemingly non-convex
optimization problem in prices, we show that (i) it can be reduced to a dual
convex optimization problem in prices, and (ii) the revealed preferences can be
interpreted as supergradients of the concave conjugate of valuation, with which
subgradients of the dual function can be computed. We thereby obtain a simple
subgradient-based algorithm for strongly concave valuations and convex cost,
with query complexity , where is the additive
difference between the social welfare induced by our algorithm and the optimum
social welfare. We also study social welfare maximization under the online
setting, specifically the random permutation model, where consumers arrive
one-by-one in a random order. For the case where consumer valuations can be
arbitrary continuous functions, we propose a price posting mechanism that
achieves an expected social welfare up to an additive factor of
from the maximum social welfare. Finally, for profit maximization (which may be
non-convex in simple cases), we give nearly matching upper and lower bounds on
the query complexity for separable valuations and cost (i.e., each good can be
treated independently)
Myocardial blood flow under general anaesthesia with sevoflurane in type 2 diabetic patients: a pilot study
BACKGROUND: In type 2 diabetic patients, cardiac events in the perioperative period may be associated with diminished myocardial vasomotor function and endothelial dysfunction. The influence of sevoflurane anaesthesia on myocardial endothelial dysfunction in type 2 diabetic mellitus is investigated in this pilot study. METHODS: Six males with type 2 diabetes mellitus and eight healthy controls were included. Using myocardial contrast echocardiography, myocardial blood flow (MBF) was measured at rest, during adenosine-induced hyperaemia (endothelium-independent vasodilation) and after sympathetic stimulation by the cold pressor test (endothelium-dependent vasodilation). Measurements were performed before and after induction of sevoflurane anaesthesia. RESULTS: Sevoflurane anaesthesia decreased resting MBF in diabetics but not in controls (P = 0.03), while baseline MBF did not differ between diabetics and controls. Without anaesthesia, adenosine-induced hyperaemia increased MBF in both groups compared to resting values. Adenosine combined with sevoflurane resulted in a lower hyperaemic MBF in both groups compared to no anaesthesia. Differences in MBF in response to adenosine before and after sevoflurane administration were larger in diabetic patients, however not statistically significant in this pilot group (P = 0.08). Myocardial blood flow parameters after the cold pressor test were not different between groups. CONCLUSION: These pilot data in type 2 diabetic patients show that sevoflurane anaesthesia decreases resting myocardial blood flow compared to healthy controls. Further, we observed a trend towards a lower endothelium-independent vasodilation capacity in diabetic patients under sevoflurane anaesthesia. Endothelium-dependent vasodilation was not affected by sevoflurane in diabetic patients. These data provide preliminary insight into myocardial responses in type 2 diabetic patients under general anaesthesia. TRIAL REGISTRATION: http://www.clinicialtrials.gov, NCT0086680
- …