Frequency response of intracavity laser coupling modulation

A resonant energy coupling between the atomic system and the oscillating optical mode leads to severe output distortion in intracavity laser coupling modulation. This anomalous behavior, which places a lower limit on the modulation frequency, is investigated in a case of a CO2 laser and compared with theoretical predictions

Elevated Ratio of Urinary Metabolites of Thromboxane and Prostacyclin Is Associated with Adverse Cardiovascular Events in ADAPT

Results from prevention trials, including the Alzheimer's Disease Anti-inflammatory Prevention Trial (ADAPT), have fueled discussion about the cardiovascular (CV) risks associated with non-steroidal anti-inflammatory drugs (NSAIDs). We tested the hypotheses that (i) adverse CV events reported among ADAPT participants (aged 70 years and older) are associated with increased ratio of urine 11-dehydrothromboxane B2 (Tx-M) to 2′3-donor–6-keto-PGF1 (PGI-M) attributable to NSAID treatments; (ii) coincident use of aspirin (ASA) would attenuate NSAID-induced changes in Tx-M/PGI-M ratio; and (iii) use of NSAIDs and/or ASA would not alter urine or plasma concentrations of F2-isoprostanes (IsoPs), in vivo biomarkers of free radical damage. We quantified urine Tx-M and PGI-M, and urine and plasma F2-IsoPs from 315 ADAPT participants using stable isotope dilution assays with gas chromatography/mass spectrometry, and analyzed these data by randomized drug assignment and self-report compliance as well as ASA use. Adverse CV events were significantly associated with higher urine Tx-M/PGI-M ratio, which seemed to derive mainly from lowered PGI-M. Participants taking ASA alone had reduced urine Tx-M/PGI-M compared to no ASA or NSAID; however, participants taking NSAIDs plus ASA did not have reduced urine Tx-M/PGI-M ratio compared to NSAIDs alone. Neither NSAID nor ASA use altered plasma or urine F2-IsoPs. These data suggest a possible mechanism for the increased risk of CV events reported in ADAPT participants assigned to NSAIDs, and suggest that the changes in the Tx-M/PGI-M ratio was not substantively mitigated by coincident use of ASA in individuals 70 years or older

A 10.6 μm TERRESTRIAL COMMUNICATION LINK*

International Telemetering Conference Proceedings / October 09-11, 1973 / Sheraton Inn Northeast, Washington, D.C.This paper reports the development of an experimental type 10.6 μm laser communication system, consisting of a transmitter terminal and a receiver terminal, designed to operate one wav over a nominal five-mile path. The system provides a 5 MB/s digital data channel using a frequency shift keying format and optical heterodyne detection with a mercury cadmium telluride detector operating at a temperature of 77°K. The system is the first CO2 laser heterodyne communication system which is capable of hands-off, uninterrupted operation in a nonlaboratory environment. The achievement of single frequency operation of a laser transmitter and local oscillator in a field system is the result of more than seven years of research and development. Laser frequency purity, stability and control, all questions of primary concern previously, have been proven satisfactory with the development of this system. This paper reports the operation of the system during environmental tests, over a 4.1-mile test range, a 19.5-mile test range at the Hughes facility, and over a three mile test range at Ft. Monmouth, N.J. over a period of several months. During a period of 1320 hours of continuous operation, the system was inoperable for 65 hours due to weather conditions, demonstrating a reliability of 95%.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Antagonism of thromboxane receptors by diclofenac and lumiracoxib

Background and purpose: Non-steroidal anti-inflammatory drugs (NSAIDs) are analgesic and anti-inflammatory by virtue of inhibition of the cyclooxygenase (COX) reaction that initiates biosynthesis of prostaglandins. Findings in a pulmonary pharmacology project gave rise to the hypothesis that certain members of the NSAID class might also be antagonists of the thromboxane (TP) receptor. Experimental approach: Functional responses due to activation of the TP receptor were studied in isolated airway and vascular smooth muscle preparations from guinea pigs and rats as well as in human platelets. Receptor binding and activation of the TP receptor was studied in HEK293 cells. Key results: Diclofenac concentration-dependently and selectively inhibited the contraction responses to TP receptor agonists such as prostaglandin D 2 and U-46619 in the tested smooth muscle preparations and the aggregation of human platelets. The competitive antagonism of the TP receptor was confirmed by binding studies and at the level of signal transduction. The selective COX-2 inhibitor lumiracoxib shared this activity profile, whereas a number of standard NSAIDs and other selective COX-2 inhibitors did not. Conclusions and implications: Diclofenac and lumiracoxib, in addition to being COX unselective and highly COX-2 selective inhibitors, respectively, displayed a previously unknown pharmacological activity, namely TP receptor antagonism. Development of COX-2 selective inhibitors with dual activity as potent TP antagonists may lead to coxibs with improved cardiovascular safety, as the TP receptor mediates cardiovascular effects of thromboxane A 2 and isoprostanes