A Three-Dimensional Solution of Flows over Wings with Leading-Edge Vortex Separation. Part 1: Engineering Document

A method of predicting forces, moments, and detailed surface pressures on thin, sharp-edged wings with leading-edge vortex separation in incompressible flow is presented. The method employs an inviscid flow model in which the wing and the rolled-up vortex sheets are represented by piecewise, continuous quadratic doublet sheet distributions. The Kutta condition is imposed on all wing edges. Computed results are compared with experimental data and with the predictions of the leading-edge suction analogy for a selected number of wing planforms over a wide range of angle of attack. These comparisons show the method to be very promising, capable of producing not only force predictions, but also accurate predictions of detailed surface pressure distributions, loads, and moments

A higher order panel method for linearized supersonic flow

The basic integral equations of linearized supersonic theory for an advanced supersonic panel method are derived. Methods using only linear varying source strength over each panel or only quadratic doublet strength over each panel gave good agreement with analytic solutions over cones and zero thickness cambered wings. For three dimensional bodies and wings of general shape, combined source and doublet panels with interior boundary conditions to eliminate the internal perturbations lead to a stable method providing good agreement experiment. A panel system with all edges contiguous resulted from dividing the basic four point non-planar panel into eight triangular subpanels, and the doublet strength was made continuous at all edges by a quadratic distribution over each subpanel. Superinclined panels were developed and tested on s simple nacelle and on an airplane model having engine inlets, with excellent results

Effect of nocturnal ventilation on the occurrence of Botrytis cinerea in Mediterranean unheated tomato greenhouses

Botrytis cinerea is the causal agent of grey mould disease which is one of the most important diseases affecting tomato crops in unheated greenhouses. Nocturnal ventilation is a technique that can be used to reduce relative humidity inside unheated greenhouses. The main objectives of this research were to investigate the effect of ventilation management on the environmental conditions and on the disease severity, to develop and validate a model which could predict disease severity and to present a warning system. Experiments were conducted in two plastic greenhouses. Two natural ventilation treatments were randomly assigned to the greenhouses. One was nocturnal ventilation (NV), with the vents open during the day and night, while the other was classical ventilation (CV), in which the vents were open during the day and closed during the night. A tomato crop was grown directly in the soil between the end of February and the end of July during two crop seasons. Climatic data were measured with three meteorological stations, averaged and recorded on an hourly basis. The number of diseased leaflets were counted and removed from the greenhouse. In the NV greenhouse a significant reduction of air humidity and disease appearance was observed. A warning system was developed and can be a useful tool for helping to decide on appropriate actions and the correct timing to avoid conditions that favour disease development. For a more practical application, disease risk levels were defined as a function of the duration of periods with RH > 90%

Mesenchymal stem cell-conditioned medium reduces disease severity and immune responses in inflammatory arthritis

We evaluated the therapeutic potential of mesenchymal stem cell-conditioned medium (CM-MSC) as an alternative to cell therapy in an antigen-induced model of arthritis (AIA). Disease severity and cartilage loss were evaluated by histopathological analysis of arthritic knee joints and immunostaining of aggrecan neoepitopes. Cell proliferation was assessed for activated and naïve CD4+ T cells from healthy mice following culture with CM-MSC or co-culture with MSCs. T cell polarization was analysed in CD4+ T cells isolated from spleens and lymph nodes of arthritic mice treated with CM-MSC or MSCs. CM-MSC treatment significantly reduced knee-joint swelling, histopathological signs of AIA, cartilage loss and suppressed TNFα induction. Proliferation of CD4+ cells from spleens of healthy mice was not affected by CM-MSC but reduced when cells were co-cultured with MSCs. In the presence of CM-MSC or MSCs, increases in IL-10 concentration were observed in culture medium. Finally, CD4+ T cells from arthritic mice treated with CM-MSC showed increases in FOXP3 and IL-4 expression and positively affected the Treg:Th17 balance in the tissue. CM-MSC treatment reduces cartilage damage and suppresses immune responses by reducing aggrecan cleavage, enhancing Treg function and adjusting the Treg:Th17 ratio. CM-MSC may provide an effective cell-free therapy for inflammatory arthritis

Concurrent Oral 1 - Rheumatoid Arthritis: Treatment [OP4-OP9]: OP4. Inhibition of Radiographic Progression and Improvements in Physical Function at 2 Years, with Increasing Clinical Efficacy Over Time, in Rheumatoid Arthritis (Ra) Patients Treated with Tocilizumab (Tcz): The Lithe Study

Background: Patients with moderate to severe RA who remained on methotrexate (MTX) despite inadequate response were treated with TCZ in a double-blind, randomized, controlled phase 3 trial. Results of a 2-year planned analysis from this study are presented. Methods: Patients were randomized to treatment with TCZ 4 mg/kg + MTX (TCZ4), TCZ 8 mg/kg + MTX (TCZ8) or placebo + MTX (CON) every 4 weeks. If patients failed to respond ( 60% of patients and the DAS28 remission (DAS28 < 2.6) rate was 48% at week 52 and continued to increase to week 104. By week 52, patients treated with TCZ8 had clinically significant improvements in SJC that were maintained through week 104. Rates per 100 PY for adverse events (AEs) were higher in TCZ8 and TCZ4 (263.6, 275.4) vs CON patients (251.4) while rates for serious AEs were comparable (11.4, 12.1, 10.9, respectively). Rates per 100 PY of AEs leading to withdrawal (7.4, 32.5, 4.8) and treatment modification (8.4, 30.7, 20.4) were higher in TCZ8 and TCZ4 vs CON patients, respectively and death rates were comparable (0.6, 0.2, 0.4). Conclusions: Treatment with TCZ + MTX inhibits radiographic progression over 2 years and improves physical function as shown by DAS28 remission, LDAS and low SJC, with a manageable safety profile. Disclosure statement: E.A., F. Hoffmann-La Roche - Employee. P.A., F. Hoffmann-La Roche - Employee. R.B.-V., F. Hoffmann-La Roche - Honoraria. R.F., Genentech - Research Funding, Honoraria. J.K., F. Hoffmann-La Roche - Research funding, Honorari

Concurrent Oral 1 - Therapy of rheumatic disease: OP4. Effectiveness of Rituximab in Rheumatoid Arthritis: Results from the British Society for Rheumatology Biologics Register (BSRBR)

Background: Rituximab (RTX) in combination with methotrexate (MTX) has been licensed since 2006 for the management of severe active rheumatoid arthritis (RA) in patients who have failed at least one anti-tumour necrosis factor (anti-TNF) therapy. Published clinical trials have demonstrated the efficacy of RTX in improving both clinical symptoms and patients' physical function. This study aimed to assess the effectiveness of RTX in RA patients treated in routine clinical practice by examining clinical and patient reported outcomes six months after receiving a first course of RTX. Methods: The analysis involved 550 RA patients registered with the BSRBR, who were starting RTX and were followed up for at least 6 months. Change in Disease Activity Score (DAS28) and European League Against Rheumatism (EULAR) response were used to assess the clinical response while change in Health Assessment Questionnaire (HAQ) score was used to assess the physical function of the patients 6 months after starting RTX. The change in DAS28 and HAQ was compared between seronegative and seropositive patients and anti-TNF naïve patients versus anti-TNF failures. The response was also compared between patients receiving RTX in combination with MTX, other non-biologic disease modifying anti-rheumatic drugs (nbDMARDs) or no nbDMARDs. Results: The mean (s.d.) age of the cohort was 59 (12) years and 78% of the patients were females. The patients had a mean (s.d.) of 15 (10) years of disease duration. 16% were biologic naïve while 84% were anti-TNF failures. 32% of the patients were seronegative and 68% were seropositive. The mean (95% CI) DAS28 at baseline was 6.2 (6.1, 6.3) which decreased to 4.8 (4.7, 4.9) at 6 months of follow up. 16% were EULAR good responders, 43% were moderate responders and 41% were non responders. The mean (95% CI) change in HAQ was −0.1 (−0.2, −0.1) (Table 1). The mean change in DAS28 was similar in seropositive and seronegative patients (p = 0.18) while the anti-TNF naïve patients showed a greater reduction in DAS28 scores than anti-TNF failures (p = 0.05). Patients receiving RTX in combination with MTX showed similar changes in DAS28 and HAQ compared to patients receiving RTX alone or with other nbDMARDs. Conclusions: RTX has proven to be effective in the routine clinical practice. Anti-TNF naïve patients seem to benefit more from RTX treatment than anti-TNF failures. Disclosure statement: The authors have declared no conflicts of interes

Cerebral perfusion changes in acute subdural hematoma

Introduction: Acute subdural hematoma (aSDH) is one of the main causes of high mortality and morbidity in traumatic brain injury. Prognosis is poor due to the rapid volume shift and mass effect. Cerebral perfusion is likely affected in this condition. This study quantifies perfusion changes in aSDH using early ER polytrauma CT with perfusion imaging (CTP). Methods: Data of 54 patients with traumatic aSDH were retrospectively collected. Glasgow Coma scale (GCS), perfusion parameters, therapeutic decisions and imaging data including hematoma thickness, midline shift, and hematoma localization were analyzed. The cortical perfusion parameters of each hemisphere, the area anterior to the hematoma (AAH), area below the hematoma (ABH), area posterior to the hematoma (PAH), and corresponding mirrored contralateral regions were determined. Results We found a significant difference in Tmax in affected and unaffected whole-hemisphere data (mean 4.0 s vs. 3.3 s, p  < 0.05) and a significantly different mean for Tmax in ABH and for the corresponding mirrored area (mABH) (mean 3.8 s vs. 3.1 s, p  < 0.05). No significant perfusion changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were found. Conclusion: There was a significant elevation of time to maximum (Tmax) values in the underlying cortical area of aSDH. Possible pathophysiological explanations, the influence on immediate surgical decision-making and further therapeutic consequences have to be evaluated

Demonstration of an ac Josephson junction laser

Superconducting electronic devices have re-emerged as contenders for both classical and quantum computing due to their fast operation speeds, low dissipation and long coherence times. An ultimate demonstration of coherence is lasing. We use one of the fundamental aspects of superconductivity, the ac Josephson effect, to demonstrate a laser made from a Josephson junction strongly coupled to a multi-mode superconducting cavity. A dc voltage bias to the junction provides a source of microwave photons, while the circuit's nonlinearity allows for efficient down-conversion of higher order Josephson frequencies down to the cavity's fundamental mode. The simple fabrication and operation allows for easy integration with a range of quantum devices, allowing for efficient on-chip generation of coherent microwave photons at low temperatures.Comment: Supplementary Information available at https://qutech.nl/kouwenhoven-lab/publications