32 research outputs found
Wideband-tuneable, nanotube mode-locked, fibre laser
Ultrashort-pulse lasers with spectral tuning capability have widespread applications in fields such as spectroscopy, biomedical research and telecommunications1–3. Mode-locked fibre lasers are convenient and powerful sources of ultrashort pulses4, and the inclusion of a broadband saturable absorber as a passive optical switch inside the laser cavity may offer tuneability over a range of wavelengths5. Semiconductor saturable absorber mirrors are widely used in fibre lasers4–6, but their operating range is typically limited to a few tens of nanometres7,8, and their fabrication can be challenging in the 1.3–1.5 mm wavelength region used for optical communications9,10. Single-walled carbon nanotubes are excellent saturable absorbers because of their subpicosecond recovery time, low saturation intensity, polarization insensitivity, and mechanical and environmental robustness11–16. Here, we engineer a nanotube–polycarbonate film with a wide bandwidth (>300 nm) around 1.55 mm, and then use it to demonstrate a 2.4 ps Er31-doped fibre laser that is tuneable from 1,518 to 1,558 nm. In principle, different diameters and chiralities of nanotubes could be combined to enable compact, mode-locked fibre lasers that are tuneable over a much broader range of wavelengths than other systems
Passive Q-switching and mode-locking for the generation of nanosecond to femtosecond pulses
Roadside Trees
The severity of the global economic crisis has put the spotlight firmly on measuring academic and research performance and productivity, and assessing its contribution, value, impact and benefit. While traditionally, research output and impact was measured by peer-publications and citations, there is increased emphasis on a “market-driven approach”, which favours the bio-, medical and technological sciences, and helped reinforce a disciplinary hierarchy in which arts and humanities research (A&HR) has struggled for attention. This article charts the changing policy environment across Ireland, the Netherlands and Norway. It draws on evidence from the HERAVALUE project which studied how different stakeholders value arts and humanities research; almost 100 interviews were conducted with representatives from the academy, policymakers and civil society these three countries. Although the arts and culture have played a distinctive nation-forming role, and continue to do so, each country has adopted very different policy responses towards A&HR
Pulmonary neutral fat embolism in dogs.
Twenty-two adult dogs were each given a single, 30-minute injection of 1.5 ml/kg body weight of pure triolein, and their pulmonary, hepatic, renal, and cerebral morphology was observed for 1, 2, 3, 4, 5, 6, 15, 24, and 48 hours; 3,4, and 5 days; 1 and 2 weeks; and 1 month after the injection. A picture of massive capillary occlusion by lipid droplets was followed by rapidly resolvable inflammatory pneumopathy of granulomatous type, leaving a normal lung at the end of the experiment. The cleaning of the capillaries may be attributed to the mechanical action of the blood flow and to the inflammatory reaction with evacuation of necrotic cells via the bronchial route. Transient pulmonary edema is attributed to increased pulmonary arterial pressure. There was no intravacular coagulation. The few pulmonary lesions observed after the triolein injection suggest that the chemical theory of neutral fat hydrolysis by pulmonary lipase and the toxicity of free fatty acids that are released should be reconsidered
Embolic pneumopathy induced by oleic acid. A systematic morphologic study.
This paper presents a systematic study of acute and chronic pulmonary lesions resulting from a single intravenous injection of oleic acid and a new fibrosis lung model is proposed: pulmonary interstitial fibrosis is obtained by means of a number of oleic acid intravenous injections. Nineteen adult dogs received 0.045 g/kg or 0.09 g/kg of oleic acid. A systematic morphologic study was carried out after 1, 2, 3, 4, 6, 12, 24, and 48 hours and 1, 2 and 4 weeks. Eleven other adult dogs received weekly one injection of 0.09 g/kg of pure oleic acid over a period of 1 to 3 months. Examination of the lung was carried out by means of light and electron microscopy and morphometry. An early stage characterized by the formation of thrombosis and cellular necrosis was followed by a repair stage with the proliferation of Type 2 cells and fibrotic foci in the subpleural areas. Lipid staining with Sudan IV allowed the onset and disappearance of lipid-laden macrophages to be ascertained. The late stage showed pulmonary fibrosis. The extent of the lesions is related to the number of oleic acid injections. Since interstitial pulmonary fibrosis invariably appeared, and only 2 dogs out of 11 died, the model is satisfactory for pathologist and physiologist
Successful removal of an intramedullary spinal paraganglioma from a dog
info:eu-repo/semantics/publishe
Focal Neurological Deficit with Sudden Onset as the First Manifestation of Sarcoidosis: A Case Report with MRI Follow-Up
Association of cadmium exposure with rapidly progressive emphysema in a smoker.
Rapidly progressive emphysema developed in a 59 year old smoker after exposure to cadmium fumes in a factory. Very high levels of cadmium in air sampled at the workplace and in the patient's blood, urine, and lung tissue confirmed massive exposure. These data strongly suggest an association between the patient's cadmium exposure and the development of emphysema