A study of plasma stability in microwave cavities by a frequency-shift analog.

"Prepared for the Air Force Ballistic Missile Division, Headquarters Air Research and Development Command, under contract AF 04 (647)-309, Thermonuclear Propulsion Research."

Radial flow behavior of artificial recharge from surface cavities,

Bibliography: p. 53.

Diseases of the ear, nose, and throat and their accessory cavities. A condensed text-book.

The colored plates are accompanied by leaves with explanatory letterpress.

Diseases of the chest, throat and nasal cavities ..

Mode of access: Internet.

Dog peritoneal and pleural cavities as bioreactors to grow autologous vascular grafts

Objective: The purpose of this study was to grow artificial blood vessels for autologous transplantation as arterial interposition grafts in a large animal model (dog). Method and results: Tubing up to 250 mm long, either bare or wrapped in biodegradable polyglycolic acid (Dexon) or nonbiodegradable polypropylene (Prolene) mesh, was inserted in the peritoneal or pleural cavity of dogs, using minimally invasive techniques, and tethered at one end to the wall with a loose suture. After 3 weeks the tubes and their tissue capsules were harvested, and the inert tubing was discarded. The wall of living tissue was uniformly 1-1.5 mm thick throughout its length, and consisted of multiple layers of myofibroblasts and matrix overlaid with a single layer of mesothelium. The myofibroblasts stained for a-smooth muscle actin, vimentin, and desmin. The bursting strength of tissue tubes with no biodegradable mesh scaffolds was in excess of 2500 mm Hg, and the suture holding strength was 11.5 N, both similar to that in dog carotid and femoral arteries. Eleven tissue tubes were transplanted as interposition grafts into the femoral artery of the same dog in which they were grown, and were harvested after 3 to 6.5 months. Eight remained patent during this time. At harvest, their lumens were lined with endothelium-like cells, and wall cells stained for alpha-actin, smooth muscle myosin, desmin and smoothelin; there was also a thick adventitia containing vasa vasorum. Conclusion: Peritoneal and pleural cavities of large animals can function as bioreactors to grow myofibroblast tubes for use as autologous vascular grafts.

Enhanced clearance of Candida albicans from the oral cavities of mice following oral administration of Lactobacillus acidophilus

Orally administered live Lactobacillus acidophilus was assessed for its capacity to enhance clearance from the oral cavity of DBA/2 mice shown previously to be 'infection prone'. L. acidophilus fed to DBA/2 mice significantly shortened the duration of colonization of the oral cavity compared to controls. Enhanced clearance of Candida albicans correlated with both early mRNA gene expression for interleukin (IL)-4 and interferon (IFN)-gamma and expression of their secreted products in cultures of cervical lymph nodes stimulated with Candida antigen. In addition rapid clearance correlated with higher levels of IFN-gamma and nitric oxide in saliva. Delayed clearance, less pronounced levels of the cytokine response, saliva IFN-gamma and nitric oxide, and later mRNA expression for IL-4 and IFN-gamma relative to feeding with the L. acidophilus isolate were noted in mice fed a different Lactobacillus isolate (L. fermentum). These observations indicate significant variations in individual isolates to activate the common mucosal system.

Quantum memory scheme based on optical fibers and cavities

An optical quantum memory scheme using two narrow-linewidth cavities and some optical fibers is proposed. The cavities are connected via an optical fiber, and the gap of each cavity can be adjusted to allow photons with a certain bandwidth to transmit through or reflect back. Hence, each cavity acts as a shutter and the photons can be stored in the optical fiber between the cavities at will. We investigate the feasibility of using this device in storing a single photon. We estimate that with current technology storage of a photon qubit for up to 50 clock cycles (round trips) could be achieved with a probability of success of 85%. We discuss how this figure could be improved.

Enhanced supercontinuum generation using multi-fibre ultra-long Raman cavities

Supercontinuum generation in a TrueWave and SMF fibre based ultra-long Raman fibre laser cavity is investigated experimentally. By including SMF in the ultra-long Raman cavity, bandwidth and flatness can be dramatically improved.

Effect of fibre base and reflectors profile on the efficiency of ultra- long laser cavities

We study the effect of fibre base and grating profile on the efficiency of ultra-long Raman lasers. We show that for the studied parameters, FBG profile does not affect the performance when operating away from the zero-dispersion wavelength.

High efficiency supercontinuum generation using ultra-long Raman fiber cavities

Supercontinuum generation in a multi-fiber ultra-long Raman fiber laser cavity is experimentally investigated for the first time. We demonstrate significantly enhanced spectral flatness and supercontinuum generation efficiency using only conventional single mode silica fiber. With a pump power of only 1.63W a ~15dB bandwidth >260 nm wide (from 1440 to >1700nm) supercontinuum source is reported with a flatness of <1dB over 180nm using an optimised hybrid TW/HNLF cavity. We address the dependence of the supercontinuum spectrum on the input pump power and ultra-long Raman cavity.

Unrepeatered transmission through ultra-long fiber laser cavities

We present a study on the potential use of ultra-longlasercavities for unrepeateredfiber communication, based on the theory of nonlinearity management. A comparison is offered between the performance of ultra-longlasers and standard bi-directional distributed amplification schemes in nonrepeated transmission. Links based on both traditional (SMF/DCF) and modern Ultrawave transmissionfibers are considered.

Performance optimization of ultra-long Raman laser cavities for quasi-lossless transmission links

Performance optimization of ultra-long Raman laser links is studied theoretically and experimentally. We demonstrate that it is possible to reduce the signal power excursion by adjusting FBG reflectivity without compromising pump efficiency. Furthermore, we experimentally demonstrate an OSNR improvement of 4.3 dB in our system after 4000 km transmission by switching from conventional erbium-doped fibre amplifiers to quasi-lossless transmission.