9,549 research outputs found
Tests of a full-scale annular ram-induction combustor for a Mach 3 cruise turbojet engine
Full-scale annular ram-induction combustor tests for Mach 3 cruise turbojet engin
Full scale tests of a short length, double annular ram induction turbojet combustor for supersonic flight
Performance tests and characteristics of short length, double annular ram induction turbojet combustion chambers for supersonic fligh
Mapping the dynamic interactions between vortex species in highly anisotropic superconductors
Here we use highly sensitive magnetisation measurements performed using a
Hall probe sensor on single crystals of highly anisotropic high temperature
superconductors to study the dynamic interactions
between the two species of vortices that exist in such superconductors. We
observe a remarkable and clearly delineated high temperature regime that
mirrors the underlying vortex phase diagram. Our results map out the parameter
space over which these dynamic interaction processes can be used to create
vortex ratchets, pumps and other fluxonic devices.Comment: 7 pages, 3 figures, to be published in Supercond. Sci. Techno
In vitro and in vivo effects of salbutamol on neutrophil function in acute lung injury
Background: Intravenous salbutamol (albuterol) reduces lung water in patients with the acute respiratory
distress syndrome (ARDS). Experimental data show that it also reduces pulmonary neutrophil accumulation or
activation and inflammation in ARDS.
Aim: To investigate the effects of salbutamol on neutrophil function.
Methods: The in vitro effects of salbutamol on neutrophil function were determined. Blood and
bronchoalveolar lavage (BAL) fluid were collected from 35 patients with acute lung injury (ALI)/ARDS, 14
patients at risk from ARDS and 7 ventilated controls at baseline and after 4 days’ treatment with placebo or
salbutamol (ALI/ARDS group). Alveolar–capillary permeability was measured in vivo by thermodilution
(PiCCO). Neutrophil activation, adhesion molecule expression and inflammatory cytokines were measured.
Results: In vitro, physiological concentrations of salbutamol had no effect on neutrophil chemotaxis, viability
or apoptosis. Patients with ALI/ARDS showed increased neutrophil activation and adhesion molecule
expression compared with at risk-patients and ventilated controls. There were associations between alveolar–
capillary permeability and BAL myeloperoxidase (r = 0.4, p = 0.038) and BAL interleukin 8 (r = 0.38,
p = 0.033). In patients with ALI/ARDS, salbutamol increased numbers of circulating neutrophils but had no
effect on alveolar neutrophils.
Conclusion: At the onset of ALI/ARDS, there is increased neutrophil recruitment and activation. Physiological
concentrations of salbutamol did not alter neutrophil chemotaxis, viability or apoptosis in vitro. In vivo,
salbutamol increased circulating neutrophils, but had no effect on alveolar neutrophils or on neutrophil
activation. These data suggest that the beneficial effects of salbutamol in reducing lung water are unrelated to
modulation of neutrophil-dependent inflammatory pathways
Regulation of vascular endothelial growth factor bioactivity in patients with acute lung injury
Background: Reduced bioactive vascular endothelial growth factor (VEGF) has been demonstrated in
several inflammatory lung conditions including the acute respiratory distress syndrome (ARDS). sVEGFR-1,
a soluble form of VEGF-1 receptor, is a potent natural inhibitor of VEGF. We hypothesised that sVEGFR-1
plays an important role in the regulation of the bioactivity of VEGF within the lung in patients with ARDS.
Methods: Forty one patients with ARDS, 12 at risk of developing ARDS, and 16 normal controls were
studied. Bioactive VEGF, total VEGF, and sVEGFR-1 were measured by ELISA in plasma and
bronchoalveolar lavage (BAL) fluid. Reverse transcriptase polymerase chain reaction for sVEGFR-1 was
performed on BAL cells.
Results: sVEGFR-1 was detectable in the BAL fluid of 48% (20/41) of patients with early ARDS (1.4–
54.8 ng/ml epithelial lining fluid (ELF)) compared with 8% (1/12) at risk patients (p = 0.017) and none of
the normal controls (p = 0.002). By day 4 sVEGFR-1 was detectable in only 2/18 ARDS patients
(p = 0.008). Patients with detectable sVEGFR-1 had lower ELF median (IQR) levels of bioactive VEGF than
those without detectable sVEGFR-1 (1415.2 (474.9–3192) pg/ml v 4761 (1349–7596.6) pg/ml, median
difference 3346 pg/ml (95% CI 305.1 to 14711.9), p = 0.016), but there was no difference in total VEGF
levels. BAL cells expressed mRNA for sVEGFR-1 and produced sVEGFR-1 protein which increased
following incubation with tumour necrosis factor a.
Conclusion: This study shows for the first time the presence of sVEGFR-1 in the BAL fluid of patients with
ARDS. This may explain the presence of reduced bioactive VEGF in patients early in the course of ARDS
Flight Tests, Performances and Flight Certification of a Twin-Engine Light Aircraft
This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS-23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled speed, stall speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate stall tests have been performed in all configurations and influence of both entry-rate and load factor on stall speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification
Putative multiple alleles at the vegetative (heterokaryon) incompatibility loci het-c and het-8 in Neurospora crassa
It has never been determined in Neurospora whether multiple alleles exist at individual het loci such that interaction between any two unlike alleles will result in an incompatibility reaction. The evidence summarized here from recombination genetics and from sampling natural populations suggests multiple allelism at two of the best studied het loci. However, an alternate explanation is not excluded that invokes linked multiple loci rather than multiple alleles
Strains for identifying and studying individual vegetative (heterokaryon) incompatibility loci in Neurospora crassa
Genetic and molecular studies of vegetative incompatibility are proceeding in several Neurospora labs. The purpose of this note is to present an expanded list of strains in the Fungal Genetics Stock Center that are potentially useful when partial diploids are employed to identify different alleles at any of the 11 known het loci of N. crassa. Some of the strains are newly deposited in FGSC. Others have previously been listed under other categories in the stock list
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