Multiplex electric discharge gas laser system

A multiple pulse electric discharge gas laser system is described in which a plurality of pulsed electric discharge gas lasers are supported in a common housing. Each laser is supplied with excitation pulses from a separate power supply. A controller, which may be a microprocessor, is connected to each power supply for controlling the application of excitation pulses to each laser so that the lasers can be fired simultaneously or in any desired sequence. The output light beams from the individual lasers may be combined or utilized independently, depending on the desired application. The individual lasers may include multiple pairs of discharge electrodes with a separate power supply connected across each electrode pair so that multiple light output beams can be generated from a single laser tube and combined or utilized separately

Paper Session III-C - Outer Space to Inner Space: The Story of the Transfer of NASA Exclimer Laser Technology to Medical Angioplasty Projects

The transfer of the NASA/JPL technology started with a phone call from three physicians at Cedars-Sinai Medical Center (CSMC) in Los Angeles in the fall of 1983. The three physicians a surgeon, Dr. Warren Grundfest and two cardiologists, Drs. Frank Litvack and James Forrester called me in a serendipitous manner. They were calling local institutions to inquire about the availability of excimer laser technology to continue experimental studies they had started at CSMC and then continued with Argonne National Laboratories in Illinois. They were looking for a site in the area to continue their experiments on excimer laser ultraviolet radiation to ablate coronary blockages in the heart. CSMC was funded to do research by the NIH and later through private donations from hospital support groups. After discussing their ideas, I suggested they visit me at NASA\u27s Jet Propulsion Laboratory (JPL). I immediately notified our biomedical program manager at JPL, Dr. Ed Beckenbach, to inform him of the meeting. At the meeting the physicians went over their current results and presented their proposed plan for collaboration. Since my group had pioneered the early development of excimer lasers and had several home-built as well as commercial excimer lasers, Dr. Beckenbach thought that this could be an ideal collaboration. Dr. Beckenbach went back to NASA Headquarters and discussed the proposed collaboration. He then notified us that, if we wrote a short proposal, we could obtain funding from the NASA Technology Utilization Office. The proposal was submitted and Dr. Beckenbach provided a discretionary charge number to begin collaboration until the proposal was formally approved and funds sent to JPL. Thus began a two and one half year collaboration between NASA, JPL, CSMC, and the NIH to study laser tissue interactions to define a suitable laser angioplasty system

Remote detection of OH

This is a remote measurement technique utilizing a XeCl excimer laser tuned to the Q sub 21 1 rotational transition of the 0-0, A-X band at 307.847 nm. A wavemeter is under development to monitor, on a pulse-to-pulse basis, both the laser lineshape and absolute wavelength. Fluorescence is detected with a multiple Fabry-Perot type filter with a spectral resolution on the order of 0.001 nm. This is tuned to the overlapping Q sub 2 2, Q sub 12 2, Q sub 2 3, and Q sub 12 3 rotational transitions at 308.986 nm. The fringe pattern from this filter is imaged using a discrete, multi-anode detector which has a photon gain of 10 to the 8th power. This permits the simultaneous monitoring of OH fluorescence, N2 and/or O2 rotational Raman scattering and broadband background levels. The use of three etalons in series provides sufficient rejection, approx. greater than 10 to the 10th power, against the laser radiation only 1.2 nm away

Lidar technology measurements and technology: Report of panel

Lidar is ready to make an important contribution to tropospheric chemistry research with a variety of spaceborne measurements that complement the measurements from passive instruments. Lidar can now be considered for near-term and far-term space missions dealing with a number of scientifically important issues in tropospheric chemistry. The evolution in the lidar missions from space are addressed and details of these missions are given. The laser availability for space missions based upon the technical data is assessed

Characterization of Self-Assembled Polyelectrolyte Complex Nanoparticles Formed from Chitosan and Pectin

Chronic wounds continue to be a global healthcare concern. Thus, the development of new nanoparticle-based therapies that treat multiple symptoms of these “non-healing” wounds without encouraging antibiotic resistance is imperative. One potential solution is to use chitosan, a naturally antimicrobial polycation, which can spontaneously form polyelectrolyte complexes when mixed with a polyanion in appropriate aqueous conditions. The requirement of at least two different polymers opens up the opportunity for us to form chitosan complexes with an additional functional polyanion. In this study, chitosan:pectin (CS:Pec) nanoparticles were synthesized using an aqueous spontaneous ionic gelation method. Systematically, a number of parameters, polymer concentration, addition order, mass ratio, and solution pH, were explored and their effect on nanoparticle formation was determined. The size and surface charge of the particles were characterized, as well as their morphology using transmission electron microscopy. The effect of polymer concentration and addition order on the nanoparticles was found to be similar to that of other chitosan:polyanion complexes. The mass ratio was tuned to create nanoparticles with a chitosan shell and a controllable positive zeta potential. The particles were stable in a pH range from 3.5 to 6.0 and lost stability after 14 days of storage in aqueous media. Due to the high positive surface charge of the particles, the innate properties of the polysaccharides used, and the harmless disassociation of the polyelectrolytes, we suggest that the development of these CS:Pec nanoparticles offers great promise as a chronic wound healing platform